* config/arm/arm.c (arm_return_in_msb): New function.

[official-gcc.git] / gcc / config / arm / arm.c

/* Output routines for GCC for ARM.
   Copyright (C) 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
   2002, 2003, 2004, 2005  Free Software Foundation, Inc.
   Contributed by Pieter `Tiggr' Schoenmakers (rcpieter@win.tue.nl)
   and Martin Simmons (@harleqn.co.uk).
   More major hacks by Richard Earnshaw (rearnsha@arm.com).

   This file is part of GCC.

   GCC is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published
   by the Free Software Foundation; either version 2, or (at your
   option) any later version.

   GCC is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
   License for more details.

   You should have received a copy of the GNU General Public License
   along with GCC; see the file COPYING.  If not, write to
   the Free Software Foundation, 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "rtl.h"
#include "tree.h"
#include "obstack.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "real.h"
#include "insn-config.h"
#include "conditions.h"
#include "output.h"
#include "insn-attr.h"
#include "flags.h"
#include "reload.h"
#include "function.h"
#include "expr.h"
#include "optabs.h"
#include "toplev.h"
#include "recog.h"
#include "ggc.h"
#include "except.h"
#include "c-pragma.h"
#include "integrate.h"
#include "tm_p.h"
#include "target.h"
#include "target-def.h"
#include "debug.h"
#include "langhooks.h"

/* Forward definitions of types.  */
typedef struct minipool_node    Mnode;
typedef struct minipool_fixup   Mfix;

const struct attribute_spec arm_attribute_table[];

/* Forward function declarations.  */
static arm_stack_offsets *arm_get_frame_offsets (void);
static void arm_add_gc_roots (void);
static int arm_gen_constant (enum rtx_code, enum machine_mode, rtx,
                             HOST_WIDE_INT, rtx, rtx, int, int);
static unsigned bit_count (unsigned long);
static int arm_address_register_rtx_p (rtx, int);
static int arm_legitimate_index_p (enum machine_mode, rtx, RTX_CODE, int);
static int thumb_base_register_rtx_p (rtx, enum machine_mode, int);
inline static int thumb_index_register_rtx_p (rtx, int);
static int thumb_far_jump_used_p (void);
static bool thumb_force_lr_save (void);
static int const_ok_for_op (HOST_WIDE_INT, enum rtx_code);
static rtx emit_sfm (int, int);
#ifndef AOF_ASSEMBLER
static bool arm_assemble_integer (rtx, unsigned int, int);
#endif
static const char *fp_const_from_val (REAL_VALUE_TYPE *);
static arm_cc get_arm_condition_code (rtx);
static HOST_WIDE_INT int_log2 (HOST_WIDE_INT);
static rtx is_jump_table (rtx);
static const char *output_multi_immediate (rtx *, const char *, const char *,
                                           int, HOST_WIDE_INT);
static const char *shift_op (rtx, HOST_WIDE_INT *);
static struct machine_function *arm_init_machine_status (void);
static void thumb_exit (FILE *, int);
static rtx is_jump_table (rtx);
static HOST_WIDE_INT get_jump_table_size (rtx);
static Mnode *move_minipool_fix_forward_ref (Mnode *, Mnode *, HOST_WIDE_INT);
static Mnode *add_minipool_forward_ref (Mfix *);
static Mnode *move_minipool_fix_backward_ref (Mnode *, Mnode *, HOST_WIDE_INT);
static Mnode *add_minipool_backward_ref (Mfix *);
static void assign_minipool_offsets (Mfix *);
static void arm_print_value (FILE *, rtx);
static void dump_minipool (rtx);
static int arm_barrier_cost (rtx);
static Mfix *create_fix_barrier (Mfix *, HOST_WIDE_INT);
static void push_minipool_barrier (rtx, HOST_WIDE_INT);
static void push_minipool_fix (rtx, HOST_WIDE_INT, rtx *, enum machine_mode,
                               rtx);
static void arm_reorg (void);
static bool note_invalid_constants (rtx, HOST_WIDE_INT, int);
static int current_file_function_operand (rtx);
static unsigned long arm_compute_save_reg0_reg12_mask (void);
static unsigned long arm_compute_save_reg_mask (void);
static unsigned long arm_isr_value (tree);
static unsigned long arm_compute_func_type (void);
static tree arm_handle_fndecl_attribute (tree *, tree, tree, int, bool *);
static tree arm_handle_isr_attribute (tree *, tree, tree, int, bool *);
#if TARGET_DLLIMPORT_DECL_ATTRIBUTES
static tree arm_handle_notshared_attribute (tree *, tree, tree, int, bool *);
#endif
static void arm_output_function_epilogue (FILE *, HOST_WIDE_INT);
static void arm_output_function_prologue (FILE *, HOST_WIDE_INT);
static void thumb_output_function_prologue (FILE *, HOST_WIDE_INT);
static int arm_comp_type_attributes (tree, tree);
static void arm_set_default_type_attributes (tree);
static int arm_adjust_cost (rtx, rtx, rtx, int);
static int count_insns_for_constant (HOST_WIDE_INT, int);
static int arm_get_strip_length (int);
static bool arm_function_ok_for_sibcall (tree, tree);
static void arm_internal_label (FILE *, const char *, unsigned long);
static void arm_output_mi_thunk (FILE *, tree, HOST_WIDE_INT, HOST_WIDE_INT,
                                 tree);
static int arm_rtx_costs_1 (rtx, enum rtx_code, enum rtx_code);
static bool arm_size_rtx_costs (rtx, int, int, int *);
static bool arm_slowmul_rtx_costs (rtx, int, int, int *);
static bool arm_fastmul_rtx_costs (rtx, int, int, int *);
static bool arm_xscale_rtx_costs (rtx, int, int, int *);
static bool arm_9e_rtx_costs (rtx, int, int, int *);
static int arm_address_cost (rtx);
static bool arm_memory_load_p (rtx);
static bool arm_cirrus_insn_p (rtx);
static void cirrus_reorg (rtx);
static void arm_init_builtins (void);
static rtx arm_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
static void arm_init_iwmmxt_builtins (void);
static rtx safe_vector_operand (rtx, enum machine_mode);
static rtx arm_expand_binop_builtin (enum insn_code, tree, rtx);
static rtx arm_expand_unop_builtin (enum insn_code, tree, rtx, int);
static rtx arm_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
static void emit_constant_insn (rtx cond, rtx pattern);
static int arm_arg_partial_bytes (CUMULATIVE_ARGS *, enum machine_mode,
                                  tree, bool);

#ifndef ARM_PE
static void arm_encode_section_info (tree, rtx, int);
#endif

static void arm_file_end (void);

#ifdef AOF_ASSEMBLER
static void aof_globalize_label (FILE *, const char *);
static void aof_dump_imports (FILE *);
static void aof_dump_pic_table (FILE *);
static void aof_file_start (void);
static void aof_file_end (void);
#endif
static rtx arm_struct_value_rtx (tree, int);
static void arm_setup_incoming_varargs (CUMULATIVE_ARGS *, enum machine_mode,
                                        tree, int *, int);
static bool arm_pass_by_reference (CUMULATIVE_ARGS *,
                                   enum machine_mode, tree, bool);
static bool arm_promote_prototypes (tree);
static bool arm_default_short_enums (void);
static bool arm_align_anon_bitfield (void);
static bool arm_return_in_msb (tree);
static bool arm_must_pass_in_stack (enum machine_mode, tree);

static tree arm_cxx_guard_type (void);
static bool arm_cxx_guard_mask_bit (void);
static tree arm_get_cookie_size (tree);
static bool arm_cookie_has_size (void);
static bool arm_cxx_cdtor_returns_this (void);
static bool arm_cxx_key_method_may_be_inline (void);
static void arm_cxx_determine_class_data_visibility (tree);
static bool arm_cxx_class_data_always_comdat (void);
static bool arm_cxx_use_aeabi_atexit (void);
static void arm_init_libfuncs (void);
static unsigned HOST_WIDE_INT arm_shift_truncation_mask (enum machine_mode);
\f
/* Initialize the GCC target structure.  */
#if TARGET_DLLIMPORT_DECL_ATTRIBUTES
#undef  TARGET_MERGE_DECL_ATTRIBUTES
#define TARGET_MERGE_DECL_ATTRIBUTES merge_dllimport_decl_attributes
#endif

#undef  TARGET_ATTRIBUTE_TABLE
#define TARGET_ATTRIBUTE_TABLE arm_attribute_table

#undef TARGET_ASM_FILE_END
#define TARGET_ASM_FILE_END arm_file_end

#ifdef AOF_ASSEMBLER
#undef  TARGET_ASM_BYTE_OP
#define TARGET_ASM_BYTE_OP "\tDCB\t"
#undef  TARGET_ASM_ALIGNED_HI_OP
#define TARGET_ASM_ALIGNED_HI_OP "\tDCW\t"
#undef  TARGET_ASM_ALIGNED_SI_OP
#define TARGET_ASM_ALIGNED_SI_OP "\tDCD\t"
#undef TARGET_ASM_GLOBALIZE_LABEL
#define TARGET_ASM_GLOBALIZE_LABEL aof_globalize_label
#undef TARGET_ASM_FILE_START
#define TARGET_ASM_FILE_START aof_file_start
#undef TARGET_ASM_FILE_END
#define TARGET_ASM_FILE_END aof_file_end
#else
#undef  TARGET_ASM_ALIGNED_SI_OP
#define TARGET_ASM_ALIGNED_SI_OP NULL
#undef  TARGET_ASM_INTEGER
#define TARGET_ASM_INTEGER arm_assemble_integer
#endif

#undef  TARGET_ASM_FUNCTION_PROLOGUE
#define TARGET_ASM_FUNCTION_PROLOGUE arm_output_function_prologue

#undef  TARGET_ASM_FUNCTION_EPILOGUE
#define TARGET_ASM_FUNCTION_EPILOGUE arm_output_function_epilogue

#undef  TARGET_COMP_TYPE_ATTRIBUTES
#define TARGET_COMP_TYPE_ATTRIBUTES arm_comp_type_attributes

#undef  TARGET_SET_DEFAULT_TYPE_ATTRIBUTES
#define TARGET_SET_DEFAULT_TYPE_ATTRIBUTES arm_set_default_type_attributes

#undef  TARGET_SCHED_ADJUST_COST
#define TARGET_SCHED_ADJUST_COST arm_adjust_cost

#undef TARGET_ENCODE_SECTION_INFO
#ifdef ARM_PE
#define TARGET_ENCODE_SECTION_INFO  arm_pe_encode_section_info
#else
#define TARGET_ENCODE_SECTION_INFO  arm_encode_section_info
#endif

#undef  TARGET_STRIP_NAME_ENCODING
#define TARGET_STRIP_NAME_ENCODING arm_strip_name_encoding

#undef  TARGET_ASM_INTERNAL_LABEL
#define TARGET_ASM_INTERNAL_LABEL arm_internal_label

#undef  TARGET_FUNCTION_OK_FOR_SIBCALL
#define TARGET_FUNCTION_OK_FOR_SIBCALL arm_function_ok_for_sibcall

#undef  TARGET_ASM_OUTPUT_MI_THUNK
#define TARGET_ASM_OUTPUT_MI_THUNK arm_output_mi_thunk
#undef  TARGET_ASM_CAN_OUTPUT_MI_THUNK
#define TARGET_ASM_CAN_OUTPUT_MI_THUNK default_can_output_mi_thunk_no_vcall

/* This will be overridden in arm_override_options.  */
#undef  TARGET_RTX_COSTS
#define TARGET_RTX_COSTS arm_slowmul_rtx_costs
#undef  TARGET_ADDRESS_COST
#define TARGET_ADDRESS_COST arm_address_cost

#undef TARGET_SHIFT_TRUNCATION_MASK
#define TARGET_SHIFT_TRUNCATION_MASK arm_shift_truncation_mask
#undef TARGET_VECTOR_MODE_SUPPORTED_P
#define TARGET_VECTOR_MODE_SUPPORTED_P arm_vector_mode_supported_p

#undef  TARGET_MACHINE_DEPENDENT_REORG
#define TARGET_MACHINE_DEPENDENT_REORG arm_reorg

#undef  TARGET_INIT_BUILTINS
#define TARGET_INIT_BUILTINS  arm_init_builtins
#undef  TARGET_EXPAND_BUILTIN
#define TARGET_EXPAND_BUILTIN arm_expand_builtin

#undef TARGET_INIT_LIBFUNCS
#define TARGET_INIT_LIBFUNCS arm_init_libfuncs

#undef TARGET_PROMOTE_FUNCTION_ARGS
#define TARGET_PROMOTE_FUNCTION_ARGS hook_bool_tree_true
#undef TARGET_PROMOTE_FUNCTION_RETURN
#define TARGET_PROMOTE_FUNCTION_RETURN hook_bool_tree_true
#undef TARGET_PROMOTE_PROTOTYPES
#define TARGET_PROMOTE_PROTOTYPES arm_promote_prototypes
#undef TARGET_PASS_BY_REFERENCE
#define TARGET_PASS_BY_REFERENCE arm_pass_by_reference
#undef TARGET_ARG_PARTIAL_BYTES
#define TARGET_ARG_PARTIAL_BYTES arm_arg_partial_bytes

#undef TARGET_STRUCT_VALUE_RTX
#define TARGET_STRUCT_VALUE_RTX arm_struct_value_rtx

#undef  TARGET_SETUP_INCOMING_VARARGS
#define TARGET_SETUP_INCOMING_VARARGS arm_setup_incoming_varargs

#undef TARGET_DEFAULT_SHORT_ENUMS
#define TARGET_DEFAULT_SHORT_ENUMS arm_default_short_enums

#undef TARGET_ALIGN_ANON_BITFIELD
#define TARGET_ALIGN_ANON_BITFIELD arm_align_anon_bitfield

#undef TARGET_CXX_GUARD_TYPE
#define TARGET_CXX_GUARD_TYPE arm_cxx_guard_type

#undef TARGET_CXX_GUARD_MASK_BIT
#define TARGET_CXX_GUARD_MASK_BIT arm_cxx_guard_mask_bit

#undef TARGET_CXX_GET_COOKIE_SIZE
#define TARGET_CXX_GET_COOKIE_SIZE arm_get_cookie_size

#undef TARGET_CXX_COOKIE_HAS_SIZE
#define TARGET_CXX_COOKIE_HAS_SIZE arm_cookie_has_size

#undef TARGET_CXX_CDTOR_RETURNS_THIS
#define TARGET_CXX_CDTOR_RETURNS_THIS arm_cxx_cdtor_returns_this

#undef TARGET_CXX_KEY_METHOD_MAY_BE_INLINE
#define TARGET_CXX_KEY_METHOD_MAY_BE_INLINE arm_cxx_key_method_may_be_inline

#undef TARGET_CXX_USE_AEABI_ATEXIT
#define TARGET_CXX_USE_AEABI_ATEXIT arm_cxx_use_aeabi_atexit

#undef TARGET_CXX_DETERMINE_CLASS_DATA_VISIBILITY
#define TARGET_CXX_DETERMINE_CLASS_DATA_VISIBILITY \
  arm_cxx_determine_class_data_visibility

#undef TARGET_CXX_CLASS_DATA_ALWAYS_COMDAT
#define TARGET_CXX_CLASS_DATA_ALWAYS_COMDAT arm_cxx_class_data_always_comdat

#undef TARGET_RETURN_IN_MSB
#define TARGET_RETURN_IN_MSB arm_return_in_msb

#undef TARGET_MUST_PASS_IN_STACK
#define TARGET_MUST_PASS_IN_STACK arm_must_pass_in_stack

struct gcc_target targetm = TARGET_INITIALIZER;
\f
/* Obstack for minipool constant handling.  */
static struct obstack minipool_obstack;
static char *         minipool_startobj;

/* The maximum number of insns skipped which
   will be conditionalised if possible.  */
static int max_insns_skipped = 5;

extern FILE * asm_out_file;

/* True if we are currently building a constant table.  */
int making_const_table;

/* Define the information needed to generate branch insns.  This is
   stored from the compare operation.  */
rtx arm_compare_op0, arm_compare_op1;

/* The processor for which instructions should be scheduled.  */
enum processor_type arm_tune = arm_none;

/* Which floating point model to use.  */
enum arm_fp_model arm_fp_model;

/* Which floating point hardware is available.  */
enum fputype arm_fpu_arch;

/* Which floating point hardware to schedule for.  */
enum fputype arm_fpu_tune;

/* Whether to use floating point hardware.  */
enum float_abi_type arm_float_abi;

/* Which ABI to use.  */
enum arm_abi_type arm_abi;

/* Set by the -mfpu=... option.  */
const char * target_fpu_name = NULL;

/* Set by the -mfpe=... option.  */
const char * target_fpe_name = NULL;

/* Set by the -mfloat-abi=... option.  */
const char * target_float_abi_name = NULL;

/* Set by the legacy -mhard-float and -msoft-float options.  */
const char * target_float_switch = NULL;

/* Set by the -mabi=... option.  */
const char * target_abi_name = NULL;

/* Used to parse -mstructure_size_boundary command line option.  */
const char * structure_size_string = NULL;
int    arm_structure_size_boundary = DEFAULT_STRUCTURE_SIZE_BOUNDARY;

/* Used for Thumb call_via trampolines.  */
rtx thumb_call_via_label[14];
static int thumb_call_reg_needed;

/* Bit values used to identify processor capabilities.  */
#define FL_CO_PROC    (1 << 0)        /* Has external co-processor bus */
#define FL_ARCH3M     (1 << 1)        /* Extended multiply */
#define FL_MODE26     (1 << 2)        /* 26-bit mode support */
#define FL_MODE32     (1 << 3)        /* 32-bit mode support */
#define FL_ARCH4      (1 << 4)        /* Architecture rel 4 */
#define FL_ARCH5      (1 << 5)        /* Architecture rel 5 */
#define FL_THUMB      (1 << 6)        /* Thumb aware */
#define FL_LDSCHED    (1 << 7)        /* Load scheduling necessary */
#define FL_STRONG     (1 << 8)        /* StrongARM */
#define FL_ARCH5E     (1 << 9)        /* DSP extensions to v5 */
#define FL_XSCALE     (1 << 10)       /* XScale */
#define FL_CIRRUS     (1 << 11)       /* Cirrus/DSP.  */
#define FL_ARCH6      (1 << 12)       /* Architecture rel 6.  Adds
                                         media instructions.  */
#define FL_VFPV2      (1 << 13)       /* Vector Floating Point V2.  */
#define FL_WBUF       (1 << 14)       /* Schedule for write buffer ops.
                                         Note: ARM6 & 7 derivatives only.  */

#define FL_IWMMXT     (1 << 29)       /* XScale v2 or "Intel Wireless MMX technology".  */

#define FL_FOR_ARCH2    0
#define FL_FOR_ARCH3    FL_MODE32
#define FL_FOR_ARCH3M   (FL_FOR_ARCH3 | FL_ARCH3M)
#define FL_FOR_ARCH4    (FL_FOR_ARCH3M | FL_ARCH4)
#define FL_FOR_ARCH4T   (FL_FOR_ARCH4 | FL_THUMB)
#define FL_FOR_ARCH5    (FL_FOR_ARCH4 | FL_ARCH5)
#define FL_FOR_ARCH5T   (FL_FOR_ARCH5 | FL_THUMB)
#define FL_FOR_ARCH5E   (FL_FOR_ARCH5 | FL_ARCH5E)
#define FL_FOR_ARCH5TE  (FL_FOR_ARCH5E | FL_THUMB)
#define FL_FOR_ARCH5TEJ FL_FOR_ARCH5TE
#define FL_FOR_ARCH6    (FL_FOR_ARCH5TE | FL_ARCH6)
#define FL_FOR_ARCH6J   FL_FOR_ARCH6
#define FL_FOR_ARCH6K   FL_FOR_ARCH6
#define FL_FOR_ARCH6Z   FL_FOR_ARCH6
#define FL_FOR_ARCH6ZK  FL_FOR_ARCH6

/* The bits in this mask specify which
   instructions we are allowed to generate.  */
static unsigned long insn_flags = 0;

/* The bits in this mask specify which instruction scheduling options should
   be used.  */
static unsigned long tune_flags = 0;

/* The following are used in the arm.md file as equivalents to bits
   in the above two flag variables.  */

/* Nonzero if this chip supports the ARM Architecture 3M extensions.  */
int arm_arch3m = 0;

/* Nonzero if this chip supports the ARM Architecture 4 extensions.  */
int arm_arch4 = 0;

/* Nonzero if this chip supports the ARM Architecture 4t extensions.  */
int arm_arch4t = 0;

/* Nonzero if this chip supports the ARM Architecture 5 extensions.  */
int arm_arch5 = 0;

/* Nonzero if this chip supports the ARM Architecture 5E extensions.  */
int arm_arch5e = 0;

/* Nonzero if this chip supports the ARM Architecture 6 extensions.  */
int arm_arch6 = 0;

/* Nonzero if this chip can benefit from load scheduling.  */
int arm_ld_sched = 0;

/* Nonzero if this chip is a StrongARM.  */
int arm_tune_strongarm = 0;

/* Nonzero if this chip is a Cirrus variant.  */
int arm_arch_cirrus = 0;

/* Nonzero if this chip supports Intel Wireless MMX technology.  */
int arm_arch_iwmmxt = 0;

/* Nonzero if this chip is an XScale.  */
int arm_arch_xscale = 0;

/* Nonzero if tuning for XScale  */
int arm_tune_xscale = 0;

/* Nonzero if we want to tune for stores that access the write-buffer. 
   This typically means an ARM6 or ARM7 with MMU or MPU.  */
int arm_tune_wbuf = 0;

/* Nonzero if generating Thumb instructions.  */
int thumb_code = 0;

/* Nonzero if we should define __THUMB_INTERWORK__ in the
   preprocessor.
   XXX This is a bit of a hack, it's intended to help work around
   problems in GLD which doesn't understand that armv5t code is
   interworking clean.  */
int arm_cpp_interwork = 0;

/* In case of a PRE_INC, POST_INC, PRE_DEC, POST_DEC memory reference, we
   must report the mode of the memory reference from PRINT_OPERAND to
   PRINT_OPERAND_ADDRESS.  */
enum machine_mode output_memory_reference_mode;

/* The register number to be used for the PIC offset register.  */
const char * arm_pic_register_string = NULL;
int arm_pic_register = INVALID_REGNUM;

/* Set to 1 when a return insn is output, this means that the epilogue
   is not needed.  */
int return_used_this_function;

/* Set to 1 after arm_reorg has started.  Reset to start at the start of
   the next function.  */
static int after_arm_reorg = 0;

/* The maximum number of insns to be used when loading a constant.  */
static int arm_constant_limit = 3;

/* For an explanation of these variables, see final_prescan_insn below.  */
int arm_ccfsm_state;
enum arm_cond_code arm_current_cc;
rtx arm_target_insn;
int arm_target_label;

/* The condition codes of the ARM, and the inverse function.  */
static const char * const arm_condition_codes[] =
{
  "eq", "ne", "cs", "cc", "mi", "pl", "vs", "vc",
  "hi", "ls", "ge", "lt", "gt", "le", "al", "nv"
};

#define streq(string1, string2) (strcmp (string1, string2) == 0)
\f
/* Initialization code.  */

struct processors
{
  const char *const name;
  enum processor_type core;
  const char *arch;
  const unsigned long flags;
  bool (* rtx_costs) (rtx, int, int, int *);
};

/* Not all of these give usefully different compilation alternatives,
   but there is no simple way of generalizing them.  */
static const struct processors all_cores[] =
{
  /* ARM Cores */
#define ARM_CORE(NAME, IDENT, ARCH, FLAGS, COSTS) \
  {NAME, arm_none, #ARCH, FLAGS | FL_FOR_ARCH##ARCH, arm_##COSTS##_rtx_costs},
#include "arm-cores.def"
#undef ARM_CORE
  {NULL, arm_none, NULL, 0, NULL}
};

static const struct processors all_architectures[] =
{
  /* ARM Architectures */
  /* We don't specify rtx_costs here as it will be figured out
     from the core.  */

  {"armv2",   arm2,       "2",   FL_CO_PROC | FL_MODE26 | FL_FOR_ARCH2, NULL},
  {"armv2a",  arm2,       "2",   FL_CO_PROC | FL_MODE26 | FL_FOR_ARCH2, NULL},
  {"armv3",   arm6,       "3",   FL_CO_PROC | FL_MODE26 | FL_FOR_ARCH3, NULL},
  {"armv3m",  arm7m,      "3M",  FL_CO_PROC | FL_MODE26 | FL_FOR_ARCH3M, NULL},
  {"armv4",   arm7tdmi,   "4",   FL_CO_PROC | FL_MODE26 | FL_FOR_ARCH4, NULL},
  /* Strictly, FL_MODE26 is a permitted option for v4t, but there are no
     implementations that support it, so we will leave it out for now.  */
  {"armv4t",  arm7tdmi,   "4T",  FL_CO_PROC |             FL_FOR_ARCH4T, NULL},
  {"armv5",   arm10tdmi,  "5",   FL_CO_PROC |             FL_FOR_ARCH5, NULL},
  {"armv5t",  arm10tdmi,  "5T",  FL_CO_PROC |             FL_FOR_ARCH5T, NULL},
  {"armv5e",  arm1026ejs, "5E",  FL_CO_PROC |             FL_FOR_ARCH5E, NULL},
  {"armv5te", arm1026ejs, "5TE", FL_CO_PROC |             FL_FOR_ARCH5TE, NULL},
  {"armv6",   arm1136js,  "6",   FL_CO_PROC |             FL_FOR_ARCH6, NULL},
  {"armv6j",  arm1136js,  "6J",  FL_CO_PROC |             FL_FOR_ARCH6J, NULL},
  {"armv6k",  mpcore,     "6K",  FL_CO_PROC |             FL_FOR_ARCH6K, NULL},
  {"armv6z",  arm1176jzs, "6Z",  FL_CO_PROC |             FL_FOR_ARCH6Z, NULL},
  {"armv6zk", arm1176jzs, "6ZK", FL_CO_PROC |             FL_FOR_ARCH6ZK, NULL},
  {"ep9312",  ep9312,     "4T",  FL_LDSCHED | FL_CIRRUS | FL_FOR_ARCH4, NULL},
  {"iwmmxt",  iwmmxt,     "5TE", FL_LDSCHED | FL_STRONG | FL_FOR_ARCH5TE | FL_XSCALE | FL_IWMMXT , NULL},
  {NULL, arm_none, NULL, 0 , NULL}
};

/* This is a magic structure.  The 'string' field is magically filled in
   with a pointer to the value specified by the user on the command line
   assuming that the user has specified such a value.  */

struct arm_cpu_select arm_select[] =
{
  /* string       name            processors  */
  { NULL,       "-mcpu=",       all_cores  },
  { NULL,       "-march=",      all_architectures },
  { NULL,       "-mtune=",      all_cores }
};


/* The name of the proprocessor macro to define for this architecture.  */

char arm_arch_name[] = "__ARM_ARCH_0UNK__";

struct fpu_desc
{
  const char * name;
  enum fputype fpu;
};


/* Available values for for -mfpu=.  */

static const struct fpu_desc all_fpus[] =
{
  {"fpa",       FPUTYPE_FPA},
  {"fpe2",      FPUTYPE_FPA_EMU2},
  {"fpe3",      FPUTYPE_FPA_EMU2},
  {"maverick",  FPUTYPE_MAVERICK},
  {"vfp",       FPUTYPE_VFP}
};


/* Floating point models used by the different hardware.
   See fputype in arm.h.  */

static const enum fputype fp_model_for_fpu[] =
{
  /* No FP hardware.  */
  ARM_FP_MODEL_UNKNOWN,         /* FPUTYPE_NONE  */
  ARM_FP_MODEL_FPA,             /* FPUTYPE_FPA  */
  ARM_FP_MODEL_FPA,             /* FPUTYPE_FPA_EMU2  */
  ARM_FP_MODEL_FPA,             /* FPUTYPE_FPA_EMU3  */
  ARM_FP_MODEL_MAVERICK,        /* FPUTYPE_MAVERICK  */
  ARM_FP_MODEL_VFP              /* FPUTYPE_VFP  */
};


struct float_abi
{
  const char * name;
  enum float_abi_type abi_type;
};


/* Available values for -mfloat-abi=.  */

static const struct float_abi all_float_abis[] =
{
  {"soft",      ARM_FLOAT_ABI_SOFT},
  {"softfp",    ARM_FLOAT_ABI_SOFTFP},
  {"hard",      ARM_FLOAT_ABI_HARD}
};


struct abi_name
{
  const char *name;
  enum arm_abi_type abi_type;
};


/* Available values for -mabi=.  */

static const struct abi_name arm_all_abis[] =
{
  {"apcs-gnu",    ARM_ABI_APCS},
  {"atpcs",   ARM_ABI_ATPCS},
  {"aapcs",   ARM_ABI_AAPCS},
  {"iwmmxt",  ARM_ABI_IWMMXT}
};

/* Return the number of bits set in VALUE.  */
static unsigned
bit_count (unsigned long value)
{
  unsigned long count = 0;

  while (value)
    {
      count++;
      value &= value - 1;  /* Clear the least-significant set bit.  */
    }

  return count;
}

/* Set up library functions unique to ARM.  */

static void
arm_init_libfuncs (void)
{
  /* There are no special library functions unless we are using the
     ARM BPABI.  */
  if (!TARGET_BPABI)
    return;

  /* The functions below are described in Section 4 of the "Run-Time
     ABI for the ARM architecture", Version 1.0.  */

  /* Double-precision floating-point arithmetic.  Table 2.  */
  set_optab_libfunc (add_optab, DFmode, "__aeabi_dadd");
  set_optab_libfunc (sdiv_optab, DFmode, "__aeabi_ddiv");
  set_optab_libfunc (smul_optab, DFmode, "__aeabi_dmul");
  set_optab_libfunc (neg_optab, DFmode, "__aeabi_dneg");
  set_optab_libfunc (sub_optab, DFmode, "__aeabi_dsub");

  /* Double-precision comparisons.  Table 3.  */
  set_optab_libfunc (eq_optab, DFmode, "__aeabi_dcmpeq");
  set_optab_libfunc (ne_optab, DFmode, NULL);
  set_optab_libfunc (lt_optab, DFmode, "__aeabi_dcmplt");
  set_optab_libfunc (le_optab, DFmode, "__aeabi_dcmple");
  set_optab_libfunc (ge_optab, DFmode, "__aeabi_dcmpge");
  set_optab_libfunc (gt_optab, DFmode, "__aeabi_dcmpgt");
  set_optab_libfunc (unord_optab, DFmode, "__aeabi_dcmpun");

  /* Single-precision floating-point arithmetic.  Table 4.  */
  set_optab_libfunc (add_optab, SFmode, "__aeabi_fadd");
  set_optab_libfunc (sdiv_optab, SFmode, "__aeabi_fdiv");
  set_optab_libfunc (smul_optab, SFmode, "__aeabi_fmul");
  set_optab_libfunc (neg_optab, SFmode, "__aeabi_fneg");
  set_optab_libfunc (sub_optab, SFmode, "__aeabi_fsub");

  /* Single-precision comparisons.  Table 5.  */
  set_optab_libfunc (eq_optab, SFmode, "__aeabi_fcmpeq");
  set_optab_libfunc (ne_optab, SFmode, NULL);
  set_optab_libfunc (lt_optab, SFmode, "__aeabi_fcmplt");
  set_optab_libfunc (le_optab, SFmode, "__aeabi_fcmple");
  set_optab_libfunc (ge_optab, SFmode, "__aeabi_fcmpge");
  set_optab_libfunc (gt_optab, SFmode, "__aeabi_fcmpgt");
  set_optab_libfunc (unord_optab, SFmode, "__aeabi_fcmpun");

  /* Floating-point to integer conversions.  Table 6.  */
  set_conv_libfunc (sfix_optab, SImode, DFmode, "__aeabi_d2iz");
  set_conv_libfunc (ufix_optab, SImode, DFmode, "__aeabi_d2uiz");
  set_conv_libfunc (sfix_optab, DImode, DFmode, "__aeabi_d2lz");
  set_conv_libfunc (ufix_optab, DImode, DFmode, "__aeabi_d2ulz");
  set_conv_libfunc (sfix_optab, SImode, SFmode, "__aeabi_f2iz");
  set_conv_libfunc (ufix_optab, SImode, SFmode, "__aeabi_f2uiz");
  set_conv_libfunc (sfix_optab, DImode, SFmode, "__aeabi_f2lz");
  set_conv_libfunc (ufix_optab, DImode, SFmode, "__aeabi_f2ulz");

  /* Conversions between floating types.  Table 7.  */
  set_conv_libfunc (trunc_optab, SFmode, DFmode, "__aeabi_d2f");
  set_conv_libfunc (sext_optab, DFmode, SFmode, "__aeabi_f2d");

  /* Integer to floating-point conversions.  Table 8.  */
  set_conv_libfunc (sfloat_optab, DFmode, SImode, "__aeabi_i2d");
  set_conv_libfunc (ufloat_optab, DFmode, SImode, "__aeabi_ui2d");
  set_conv_libfunc (sfloat_optab, DFmode, DImode, "__aeabi_l2d");
  set_conv_libfunc (ufloat_optab, DFmode, DImode, "__aeabi_ul2d");
  set_conv_libfunc (sfloat_optab, SFmode, SImode, "__aeabi_i2f");
  set_conv_libfunc (ufloat_optab, SFmode, SImode, "__aeabi_ui2f");
  set_conv_libfunc (sfloat_optab, SFmode, DImode, "__aeabi_l2f");
  set_conv_libfunc (ufloat_optab, SFmode, DImode, "__aeabi_ul2f");

  /* Long long.  Table 9.  */
  set_optab_libfunc (smul_optab, DImode, "__aeabi_lmul");
  set_optab_libfunc (sdivmod_optab, DImode, "__aeabi_ldivmod");
  set_optab_libfunc (udivmod_optab, DImode, "__aeabi_uldivmod");
  set_optab_libfunc (ashl_optab, DImode, "__aeabi_llsl");
  set_optab_libfunc (lshr_optab, DImode, "__aeabi_llsr");
  set_optab_libfunc (ashr_optab, DImode, "__aeabi_lasr");
  set_optab_libfunc (cmp_optab, DImode, "__aeabi_lcmp");
  set_optab_libfunc (ucmp_optab, DImode, "__aeabi_ulcmp");

  /* Integer (32/32->32) division.  \S 4.3.1.  */
  set_optab_libfunc (sdivmod_optab, SImode, "__aeabi_idivmod");
  set_optab_libfunc (udivmod_optab, SImode, "__aeabi_uidivmod");

  /* The divmod functions are designed so that they can be used for
     plain division, even though they return both the quotient and the
     remainder.  The quotient is returned in the usual location (i.e.,
     r0 for SImode, {r0, r1} for DImode), just as would be expected
     for an ordinary division routine.  Because the AAPCS calling
     conventions specify that all of { r0, r1, r2, r3 } are
     callee-saved registers, there is no need to tell the compiler
     explicitly that those registers are clobbered by these
     routines.  */
  set_optab_libfunc (sdiv_optab, DImode, "__aeabi_ldivmod");
  set_optab_libfunc (udiv_optab, DImode, "__aeabi_uldivmod");
  set_optab_libfunc (sdiv_optab, SImode, "__aeabi_idivmod");
  set_optab_libfunc (udiv_optab, SImode, "__aeabi_uidivmod");

  /* We don't have mod libcalls.  Fortunately gcc knows how to use the
     divmod libcalls instead.  */
  set_optab_libfunc (smod_optab, DImode, NULL);
  set_optab_libfunc (umod_optab, DImode, NULL);
  set_optab_libfunc (smod_optab, SImode, NULL);
  set_optab_libfunc (umod_optab, SImode, NULL);
}

/* Fix up any incompatible options that the user has specified.
   This has now turned into a maze.  */
void
arm_override_options (void)
{
  unsigned i;

  /* Set up the flags based on the cpu/architecture selected by the user.  */
  for (i = ARRAY_SIZE (arm_select); i--;)
    {
      struct arm_cpu_select * ptr = arm_select + i;

      if (ptr->string != NULL && ptr->string[0] != '\0')
        {
          const struct processors * sel;

          for (sel = ptr->processors; sel->name != NULL; sel++)
            if (streq (ptr->string, sel->name))
              {
                /* Set the architecture define.  */
                if (i != 2)
                  sprintf (arm_arch_name, "__ARM_ARCH_%s__", sel->arch);

                /* Determine the processor core for which we should
                   tune code-generation.  */
                if (/* -mcpu= is a sensible default.  */
                    i == 0
                    /* If -march= is used, and -mcpu= has not been used,
                       assume that we should tune for a representative
                       CPU from that architecture.  */
                    || i == 1
                    /* -mtune= overrides -mcpu= and -march=.  */
                    || i == 2)
                  arm_tune = (enum processor_type) (sel - ptr->processors);

                if (i != 2)
                  {
                    /* If we have been given an architecture and a processor
                       make sure that they are compatible.  We only generate
                       a warning though, and we prefer the CPU over the
                       architecture.  */
                    if (insn_flags != 0 && (insn_flags ^ sel->flags))
                      warning (0, "switch -mcpu=%s conflicts with -march= switch",
                               ptr->string);

                    insn_flags = sel->flags;
                  }

                break;
              }

          if (sel->name == NULL)
            error ("bad value (%s) for %s switch", ptr->string, ptr->name);
        }
    }

  /* If the user did not specify a processor, choose one for them.  */
  if (insn_flags == 0)
    {
      const struct processors * sel;
      unsigned int        sought;
      enum processor_type cpu;

      cpu = TARGET_CPU_DEFAULT;
      if (cpu == arm_none)
        {
#ifdef SUBTARGET_CPU_DEFAULT
          /* Use the subtarget default CPU if none was specified by
             configure.  */
          cpu = SUBTARGET_CPU_DEFAULT;
#endif
          /* Default to ARM6.  */
          if (cpu == arm_none)
            cpu = arm6;
        }
      sel = &all_cores[cpu];

      insn_flags = sel->flags;

      /* Now check to see if the user has specified some command line
         switch that require certain abilities from the cpu.  */
      sought = 0;

      if (TARGET_INTERWORK || TARGET_THUMB)
        {
          sought |= (FL_THUMB | FL_MODE32);

          /* There are no ARM processors that support both APCS-26 and
             interworking.  Therefore we force FL_MODE26 to be removed
             from insn_flags here (if it was set), so that the search
             below will always be able to find a compatible processor.  */
          insn_flags &= ~FL_MODE26;
        }

      if (sought != 0 && ((sought & insn_flags) != sought))
        {
          /* Try to locate a CPU type that supports all of the abilities
             of the default CPU, plus the extra abilities requested by
             the user.  */
          for (sel = all_cores; sel->name != NULL; sel++)
            if ((sel->flags & sought) == (sought | insn_flags))
              break;

          if (sel->name == NULL)
            {
              unsigned current_bit_count = 0;
              const struct processors * best_fit = NULL;

              /* Ideally we would like to issue an error message here
                 saying that it was not possible to find a CPU compatible
                 with the default CPU, but which also supports the command
                 line options specified by the programmer, and so they
                 ought to use the -mcpu=<name> command line option to
                 override the default CPU type.

                 If we cannot find a cpu that has both the
                 characteristics of the default cpu and the given
                 command line options we scan the array again looking
                 for a best match.  */
              for (sel = all_cores; sel->name != NULL; sel++)
                if ((sel->flags & sought) == sought)
                  {
                    unsigned count;

                    count = bit_count (sel->flags & insn_flags);

                    if (count >= current_bit_count)
                      {
                        best_fit = sel;
                        current_bit_count = count;
                      }
                  }

              if (best_fit == NULL)
                abort ();
              else
                sel = best_fit;
            }

          insn_flags = sel->flags;
        }
      sprintf (arm_arch_name, "__ARM_ARCH_%s__", sel->arch);
      if (arm_tune == arm_none)
        arm_tune = (enum processor_type) (sel - all_cores);
    }

  /* The processor for which we should tune should now have been
     chosen.  */
  if (arm_tune == arm_none)
    abort ();

  tune_flags = all_cores[(int)arm_tune].flags;
  if (optimize_size)
    targetm.rtx_costs = arm_size_rtx_costs;
  else
    targetm.rtx_costs = all_cores[(int)arm_tune].rtx_costs;

  /* Make sure that the processor choice does not conflict with any of the
     other command line choices.  */
  if (TARGET_INTERWORK && !(insn_flags & FL_THUMB))
    {
      warning (0, "target CPU does not support interworking" );
      target_flags &= ~ARM_FLAG_INTERWORK;
    }

  if (TARGET_THUMB && !(insn_flags & FL_THUMB))
    {
      warning (0, "target CPU does not support THUMB instructions");
      target_flags &= ~ARM_FLAG_THUMB;
    }

  if (TARGET_APCS_FRAME && TARGET_THUMB)
    {
      /* warning (0, "ignoring -mapcs-frame because -mthumb was used"); */
      target_flags &= ~ARM_FLAG_APCS_FRAME;
    }

  /* TARGET_BACKTRACE calls leaf_function_p, which causes a crash if done
     from here where no function is being compiled currently.  */
  if ((target_flags & (THUMB_FLAG_LEAF_BACKTRACE | THUMB_FLAG_BACKTRACE))
      && TARGET_ARM)
    warning (0, "enabling backtrace support is only meaningful when compiling for the Thumb");

  if (TARGET_ARM && TARGET_CALLEE_INTERWORKING)
    warning (0, "enabling callee interworking support is only meaningful when compiling for the Thumb");

  if (TARGET_ARM && TARGET_CALLER_INTERWORKING)
    warning (0, "enabling caller interworking support is only meaningful when compiling for the Thumb");

  if (TARGET_APCS_STACK && !TARGET_APCS_FRAME)
    {
      warning (0, "-mapcs-stack-check incompatible with -mno-apcs-frame");
      target_flags |= ARM_FLAG_APCS_FRAME;
    }

  if (TARGET_POKE_FUNCTION_NAME)
    target_flags |= ARM_FLAG_APCS_FRAME;

  if (TARGET_APCS_REENT && flag_pic)
    error ("-fpic and -mapcs-reent are incompatible");

  if (TARGET_APCS_REENT)
    warning (0, "APCS reentrant code not supported.  Ignored");

  /* If this target is normally configured to use APCS frames, warn if they
     are turned off and debugging is turned on.  */
  if (TARGET_ARM
      && write_symbols != NO_DEBUG
      && !TARGET_APCS_FRAME
      && (TARGET_DEFAULT & ARM_FLAG_APCS_FRAME))
    warning (0, "-g with -mno-apcs-frame may not give sensible debugging");

  /* If stack checking is disabled, we can use r10 as the PIC register,
     which keeps r9 available.  */
  if (flag_pic)
    arm_pic_register = TARGET_APCS_STACK ? 9 : 10;

  if (TARGET_APCS_FLOAT)
    warning (0, "passing floating point arguments in fp regs not yet supported");

  /* Initialize boolean versions of the flags, for use in the arm.md file.  */
  arm_arch3m = (insn_flags & FL_ARCH3M) != 0;
  arm_arch4 = (insn_flags & FL_ARCH4) != 0;
  arm_arch4t = arm_arch4 & ((insn_flags & FL_THUMB) != 0);
  arm_arch5 = (insn_flags & FL_ARCH5) != 0;
  arm_arch5e = (insn_flags & FL_ARCH5E) != 0;
  arm_arch6 = (insn_flags & FL_ARCH6) != 0;
  arm_arch_xscale = (insn_flags & FL_XSCALE) != 0;
  arm_arch_cirrus = (insn_flags & FL_CIRRUS) != 0;

  arm_ld_sched = (tune_flags & FL_LDSCHED) != 0;
  arm_tune_strongarm = (tune_flags & FL_STRONG) != 0;
  thumb_code = (TARGET_ARM == 0);
  arm_tune_wbuf = (tune_flags & FL_WBUF) != 0;
  arm_tune_xscale = (tune_flags & FL_XSCALE) != 0;
  arm_arch_iwmmxt = (insn_flags & FL_IWMMXT) != 0;

  /* V5 code we generate is completely interworking capable, so we turn off
     TARGET_INTERWORK here to avoid many tests later on.  */

  /* XXX However, we must pass the right pre-processor defines to CPP
     or GLD can get confused.  This is a hack.  */
  if (TARGET_INTERWORK)
    arm_cpp_interwork = 1;

  if (arm_arch5)
    target_flags &= ~ARM_FLAG_INTERWORK;

  if (target_abi_name)
    {
      for (i = 0; i < ARRAY_SIZE (arm_all_abis); i++)
        {
          if (streq (arm_all_abis[i].name, target_abi_name))
            {
              arm_abi = arm_all_abis[i].abi_type;
              break;
            }
        }
      if (i == ARRAY_SIZE (arm_all_abis))
        error ("invalid ABI option: -mabi=%s", target_abi_name);
    }
  else
    arm_abi = ARM_DEFAULT_ABI;

  if (TARGET_IWMMXT && !ARM_DOUBLEWORD_ALIGN)
    error ("iwmmxt requires an AAPCS compatible ABI for proper operation");

  if (TARGET_IWMMXT_ABI && !TARGET_IWMMXT)
    error ("iwmmxt abi requires an iwmmxt capable cpu");

  arm_fp_model = ARM_FP_MODEL_UNKNOWN;
  if (target_fpu_name == NULL && target_fpe_name != NULL)
    {
      if (streq (target_fpe_name, "2"))
        target_fpu_name = "fpe2";
      else if (streq (target_fpe_name, "3"))
        target_fpu_name = "fpe3";
      else
        error ("invalid floating point emulation option: -mfpe=%s",
               target_fpe_name);
    }
  if (target_fpu_name != NULL)
    {
      /* The user specified a FPU.  */
      for (i = 0; i < ARRAY_SIZE (all_fpus); i++)
        {
          if (streq (all_fpus[i].name, target_fpu_name))
            {
              arm_fpu_arch = all_fpus[i].fpu;
              arm_fpu_tune = arm_fpu_arch;
              arm_fp_model = fp_model_for_fpu[arm_fpu_arch];
              break;
            }
        }
      if (arm_fp_model == ARM_FP_MODEL_UNKNOWN)
        error ("invalid floating point option: -mfpu=%s", target_fpu_name);
    }
  else
    {
#ifdef FPUTYPE_DEFAULT
      /* Use the default if it is specified for this platform.  */
      arm_fpu_arch = FPUTYPE_DEFAULT;
      arm_fpu_tune = FPUTYPE_DEFAULT;
#else
      /* Pick one based on CPU type.  */
      /* ??? Some targets assume FPA is the default.
      if ((insn_flags & FL_VFP) != 0)
        arm_fpu_arch = FPUTYPE_VFP;
      else
      */
      if (arm_arch_cirrus)
        arm_fpu_arch = FPUTYPE_MAVERICK;
      else
        arm_fpu_arch = FPUTYPE_FPA_EMU2;
#endif
      if (tune_flags & FL_CO_PROC && arm_fpu_arch == FPUTYPE_FPA_EMU2)
        arm_fpu_tune = FPUTYPE_FPA;
      else
        arm_fpu_tune = arm_fpu_arch;
      arm_fp_model = fp_model_for_fpu[arm_fpu_arch];
      if (arm_fp_model == ARM_FP_MODEL_UNKNOWN)
        abort ();
    }

  if (target_float_abi_name != NULL)
    {
      /* The user specified a FP ABI.  */
      for (i = 0; i < ARRAY_SIZE (all_float_abis); i++)
        {
          if (streq (all_float_abis[i].name, target_float_abi_name))
            {
              arm_float_abi = all_float_abis[i].abi_type;
              break;
            }
        }
      if (i == ARRAY_SIZE (all_float_abis))
        error ("invalid floating point abi: -mfloat-abi=%s",
               target_float_abi_name);
    }
  else if (target_float_switch)
    {
      /* This is a bit of a hack to avoid needing target flags for these.  */
      if (target_float_switch[0] == 'h')
        arm_float_abi = ARM_FLOAT_ABI_HARD;
      else
        arm_float_abi = ARM_FLOAT_ABI_SOFT;
    }
  else
    arm_float_abi = TARGET_DEFAULT_FLOAT_ABI;

  if (arm_float_abi == ARM_FLOAT_ABI_HARD && TARGET_VFP)
    sorry ("-mfloat-abi=hard and VFP");

  /* If soft-float is specified then don't use FPU.  */
  if (TARGET_SOFT_FLOAT)
    arm_fpu_arch = FPUTYPE_NONE;

  /* For arm2/3 there is no need to do any scheduling if there is only
     a floating point emulator, or we are doing software floating-point.  */
  if ((TARGET_SOFT_FLOAT
       || arm_fpu_tune == FPUTYPE_FPA_EMU2
       || arm_fpu_tune == FPUTYPE_FPA_EMU3)
      && (tune_flags & FL_MODE32) == 0)
    flag_schedule_insns = flag_schedule_insns_after_reload = 0;

  /* Override the default structure alignment for AAPCS ABI.  */
  if (arm_abi == ARM_ABI_AAPCS)
    arm_structure_size_boundary = 8;

  if (structure_size_string != NULL)
    {
      int size = strtol (structure_size_string, NULL, 0);

      if (size == 8 || size == 32
          || (ARM_DOUBLEWORD_ALIGN && size == 64))
        arm_structure_size_boundary = size;
      else
        warning (0, "structure size boundary can only be set to %s",
                 ARM_DOUBLEWORD_ALIGN ? "8, 32 or 64": "8 or 32");
    }

  if (arm_pic_register_string != NULL)
    {
      int pic_register = decode_reg_name (arm_pic_register_string);

      if (!flag_pic)
        warning (0, "-mpic-register= is useless without -fpic");

      /* Prevent the user from choosing an obviously stupid PIC register.  */
      else if (pic_register < 0 || call_used_regs[pic_register]
               || pic_register == HARD_FRAME_POINTER_REGNUM
               || pic_register == STACK_POINTER_REGNUM
               || pic_register >= PC_REGNUM)
        error ("unable to use '%s' for PIC register", arm_pic_register_string);
      else
        arm_pic_register = pic_register;
    }

  if (TARGET_THUMB && flag_schedule_insns)
    {
      /* Don't warn since it's on by default in -O2.  */
      flag_schedule_insns = 0;
    }

  if (optimize_size)
    {
      /* There's some dispute as to whether this should be 1 or 2.  However,
         experiments seem to show that in pathological cases a setting of
         1 degrades less severely than a setting of 2.  This could change if
         other parts of the compiler change their behavior.  */
      arm_constant_limit = 1;

      /* If optimizing for size, bump the number of instructions that we
         are prepared to conditionally execute (even on a StrongARM).  */
      max_insns_skipped = 6;
    }
  else
    {
      /* For processors with load scheduling, it never costs more than
         2 cycles to load a constant, and the load scheduler may well
         reduce that to 1.  */
      if (arm_ld_sched)
        arm_constant_limit = 1;

      /* On XScale the longer latency of a load makes it more difficult
         to achieve a good schedule, so it's faster to synthesize
         constants that can be done in two insns.  */
      if (arm_tune_xscale)
        arm_constant_limit = 2;

      /* StrongARM has early execution of branches, so a sequence
         that is worth skipping is shorter.  */
      if (arm_tune_strongarm)
        max_insns_skipped = 3;
    }

  /* Register global variables with the garbage collector.  */
  arm_add_gc_roots ();
}

static void
arm_add_gc_roots (void)
{
  gcc_obstack_init(&minipool_obstack);
  minipool_startobj = (char *) obstack_alloc (&minipool_obstack, 0);
}
\f
/* A table of known ARM exception types.
   For use with the interrupt function attribute.  */

typedef struct
{
  const char *const arg;
  const unsigned long return_value;
}
isr_attribute_arg;

static const isr_attribute_arg isr_attribute_args [] =
{
  { "IRQ",   ARM_FT_ISR },
  { "irq",   ARM_FT_ISR },
  { "FIQ",   ARM_FT_FIQ },
  { "fiq",   ARM_FT_FIQ },
  { "ABORT", ARM_FT_ISR },
  { "abort", ARM_FT_ISR },
  { "ABORT", ARM_FT_ISR },
  { "abort", ARM_FT_ISR },
  { "UNDEF", ARM_FT_EXCEPTION },
  { "undef", ARM_FT_EXCEPTION },
  { "SWI",   ARM_FT_EXCEPTION },
  { "swi",   ARM_FT_EXCEPTION },
  { NULL,    ARM_FT_NORMAL }
};

/* Returns the (interrupt) function type of the current
   function, or ARM_FT_UNKNOWN if the type cannot be determined.  */

static unsigned long
arm_isr_value (tree argument)
{
  const isr_attribute_arg * ptr;
  const char *              arg;

  /* No argument - default to IRQ.  */
  if (argument == NULL_TREE)
    return ARM_FT_ISR;

  /* Get the value of the argument.  */
  if (TREE_VALUE (argument) == NULL_TREE
      || TREE_CODE (TREE_VALUE (argument)) != STRING_CST)
    return ARM_FT_UNKNOWN;

  arg = TREE_STRING_POINTER (TREE_VALUE (argument));

  /* Check it against the list of known arguments.  */
  for (ptr = isr_attribute_args; ptr->arg != NULL; ptr++)
    if (streq (arg, ptr->arg))
      return ptr->return_value;

  /* An unrecognized interrupt type.  */
  return ARM_FT_UNKNOWN;
}

/* Computes the type of the current function.  */

static unsigned long
arm_compute_func_type (void)
{
  unsigned long type = ARM_FT_UNKNOWN;
  tree a;
  tree attr;

  if (TREE_CODE (current_function_decl) != FUNCTION_DECL)
    abort ();

  /* Decide if the current function is volatile.  Such functions
     never return, and many memory cycles can be saved by not storing
     register values that will never be needed again.  This optimization
     was added to speed up context switching in a kernel application.  */
  if (optimize > 0
      && TREE_NOTHROW (current_function_decl)
      && TREE_THIS_VOLATILE (current_function_decl))
    type |= ARM_FT_VOLATILE;

  if (cfun->static_chain_decl != NULL)
    type |= ARM_FT_NESTED;

  attr = DECL_ATTRIBUTES (current_function_decl);

  a = lookup_attribute ("naked", attr);
  if (a != NULL_TREE)
    type |= ARM_FT_NAKED;

  a = lookup_attribute ("isr", attr);
  if (a == NULL_TREE)
    a = lookup_attribute ("interrupt", attr);

  if (a == NULL_TREE)
    type |= TARGET_INTERWORK ? ARM_FT_INTERWORKED : ARM_FT_NORMAL;
  else
    type |= arm_isr_value (TREE_VALUE (a));

  return type;
}

/* Returns the type of the current function.  */

unsigned long
arm_current_func_type (void)
{
  if (ARM_FUNC_TYPE (cfun->machine->func_type) == ARM_FT_UNKNOWN)
    cfun->machine->func_type = arm_compute_func_type ();

  return cfun->machine->func_type;
}
\f
/* Return 1 if it is possible to return using a single instruction.
   If SIBLING is non-null, this is a test for a return before a sibling
   call.  SIBLING is the call insn, so we can examine its register usage.  */

int
use_return_insn (int iscond, rtx sibling)
{
  int regno;
  unsigned int func_type;
  unsigned long saved_int_regs;
  unsigned HOST_WIDE_INT stack_adjust;
  arm_stack_offsets *offsets;

  /* Never use a return instruction before reload has run.  */
  if (!reload_completed)
    return 0;

  func_type = arm_current_func_type ();

  /* Naked functions and volatile functions need special
     consideration.  */
  if (func_type & (ARM_FT_VOLATILE | ARM_FT_NAKED))
    return 0;

  /* So do interrupt functions that use the frame pointer.  */
  if (IS_INTERRUPT (func_type) && frame_pointer_needed)
    return 0;

  offsets = arm_get_frame_offsets ();
  stack_adjust = offsets->outgoing_args - offsets->saved_regs;

  /* As do variadic functions.  */
  if (current_function_pretend_args_size
      || cfun->machine->uses_anonymous_args
      /* Or if the function calls __builtin_eh_return () */
      || current_function_calls_eh_return
      /* Or if the function calls alloca */
      || current_function_calls_alloca
      /* Or if there is a stack adjustment.  However, if the stack pointer
         is saved on the stack, we can use a pre-incrementing stack load.  */
      || !(stack_adjust == 0 || (frame_pointer_needed && stack_adjust == 4)))
    return 0;

  saved_int_regs = arm_compute_save_reg_mask ();

  /* Unfortunately, the insn

       ldmib sp, {..., sp, ...}

     triggers a bug on most SA-110 based devices, such that the stack
     pointer won't be correctly restored if the instruction takes a
     page fault.  We work around this problem by popping r3 along with
     the other registers, since that is never slower than executing
     another instruction.

     We test for !arm_arch5 here, because code for any architecture
     less than this could potentially be run on one of the buggy
     chips.  */
  if (stack_adjust == 4 && !arm_arch5)
    {
      /* Validate that r3 is a call-clobbered register (always true in
         the default abi) ...  */
      if (!call_used_regs[3])
        return 0;

      /* ... that it isn't being used for a return value (always true
         until we implement return-in-regs), or for a tail-call
         argument ...  */
      if (sibling)
        {
          if (GET_CODE (sibling) != CALL_INSN)
            abort ();

          if (find_regno_fusage (sibling, USE, 3))
            return 0;
        }

      /* ... and that there are no call-saved registers in r0-r2
         (always true in the default ABI).  */
      if (saved_int_regs & 0x7)
        return 0;
    }

  /* Can't be done if interworking with Thumb, and any registers have been
     stacked.  */
  if (TARGET_INTERWORK && saved_int_regs != 0)
    return 0;

  /* On StrongARM, conditional returns are expensive if they aren't
     taken and multiple registers have been stacked.  */
  if (iscond && arm_tune_strongarm)
    {
      /* Conditional return when just the LR is stored is a simple
         conditional-load instruction, that's not expensive.  */
      if (saved_int_regs != 0 && saved_int_regs != (1 << LR_REGNUM))
        return 0;

      if (flag_pic && regs_ever_live[PIC_OFFSET_TABLE_REGNUM])
        return 0;
    }

  /* If there are saved registers but the LR isn't saved, then we need
     two instructions for the return.  */
  if (saved_int_regs && !(saved_int_regs & (1 << LR_REGNUM)))
    return 0;

  /* Can't be done if any of the FPA regs are pushed,
     since this also requires an insn.  */
  if (TARGET_HARD_FLOAT && TARGET_FPA)
    for (regno = FIRST_FPA_REGNUM; regno <= LAST_FPA_REGNUM; regno++)
      if (regs_ever_live[regno] && !call_used_regs[regno])
        return 0;

  /* Likewise VFP regs.  */
  if (TARGET_HARD_FLOAT && TARGET_VFP)
    for (regno = FIRST_VFP_REGNUM; regno <= LAST_VFP_REGNUM; regno++)
      if (regs_ever_live[regno] && !call_used_regs[regno])
        return 0;

  if (TARGET_REALLY_IWMMXT)
    for (regno = FIRST_IWMMXT_REGNUM; regno <= LAST_IWMMXT_REGNUM; regno++)
      if (regs_ever_live[regno] && ! call_used_regs [regno])
        return 0;

  return 1;
}

/* Return TRUE if int I is a valid immediate ARM constant.  */

int
const_ok_for_arm (HOST_WIDE_INT i)
{
  unsigned HOST_WIDE_INT mask = ~(unsigned HOST_WIDE_INT)0xFF;

  /* For machines with >32 bit HOST_WIDE_INT, the bits above bit 31 must
     be all zero, or all one.  */
  if ((i & ~(unsigned HOST_WIDE_INT) 0xffffffff) != 0
      && ((i & ~(unsigned HOST_WIDE_INT) 0xffffffff)
          != ((~(unsigned HOST_WIDE_INT) 0)
              & ~(unsigned HOST_WIDE_INT) 0xffffffff)))
    return FALSE;

  /* Fast return for 0 and powers of 2 */
  if ((i & (i - 1)) == 0)
    return TRUE;

  do
    {
      if ((i & mask & (unsigned HOST_WIDE_INT) 0xffffffff) == 0)
        return TRUE;
      mask =
          (mask << 2) | ((mask & (unsigned HOST_WIDE_INT) 0xffffffff)
                          >> (32 - 2)) | ~(unsigned HOST_WIDE_INT) 0xffffffff;
    }
  while (mask != ~(unsigned HOST_WIDE_INT) 0xFF);

  return FALSE;
}

/* Return true if I is a valid constant for the operation CODE.  */
static int
const_ok_for_op (HOST_WIDE_INT i, enum rtx_code code)
{
  if (const_ok_for_arm (i))
    return 1;

  switch (code)
    {
    case PLUS:
      return const_ok_for_arm (ARM_SIGN_EXTEND (-i));

    case MINUS:         /* Should only occur with (MINUS I reg) => rsb */
    case XOR:
    case IOR:
      return 0;

    case AND:
      return const_ok_for_arm (ARM_SIGN_EXTEND (~i));

    default:
      abort ();
    }
}

/* Emit a sequence of insns to handle a large constant.
   CODE is the code of the operation required, it can be any of SET, PLUS,
   IOR, AND, XOR, MINUS;
   MODE is the mode in which the operation is being performed;
   VAL is the integer to operate on;
   SOURCE is the other operand (a register, or a null-pointer for SET);
   SUBTARGETS means it is safe to create scratch registers if that will
   either produce a simpler sequence, or we will want to cse the values.
   Return value is the number of insns emitted.  */

int
arm_split_constant (enum rtx_code code, enum machine_mode mode, rtx insn,
                    HOST_WIDE_INT val, rtx target, rtx source, int subtargets)
{
  rtx cond;

  if (insn && GET_CODE (PATTERN (insn)) == COND_EXEC)
    cond = COND_EXEC_TEST (PATTERN (insn));
  else
    cond = NULL_RTX;

  if (subtargets || code == SET
      || (GET_CODE (target) == REG && GET_CODE (source) == REG
          && REGNO (target) != REGNO (source)))
    {
      /* After arm_reorg has been called, we can't fix up expensive
         constants by pushing them into memory so we must synthesize
         them in-line, regardless of the cost.  This is only likely to
         be more costly on chips that have load delay slots and we are
         compiling without running the scheduler (so no splitting
         occurred before the final instruction emission).

         Ref: gcc -O1 -mcpu=strongarm gcc.c-torture/compile/980506-2.c
      */
      if (!after_arm_reorg
          && !cond
          && (arm_gen_constant (code, mode, NULL_RTX, val, target, source,
                                1, 0)
              > arm_constant_limit + (code != SET)))
        {
          if (code == SET)
            {
              /* Currently SET is the only monadic value for CODE, all
                 the rest are diadic.  */
              emit_insn (gen_rtx_SET (VOIDmode, target, GEN_INT (val)));
              return 1;
            }
          else
            {
              rtx temp = subtargets ? gen_reg_rtx (mode) : target;

              emit_insn (gen_rtx_SET (VOIDmode, temp, GEN_INT (val)));
              /* For MINUS, the value is subtracted from, since we never
                 have subtraction of a constant.  */
              if (code == MINUS)
                emit_insn (gen_rtx_SET (VOIDmode, target,
                                        gen_rtx_MINUS (mode, temp, source)));
              else
                emit_insn (gen_rtx_SET (VOIDmode, target,
                                        gen_rtx_fmt_ee (code, mode, source, temp)));
              return 2;
            }
        }
    }

  return arm_gen_constant (code, mode, cond, val, target, source, subtargets,
                           1);
}

static int
count_insns_for_constant (HOST_WIDE_INT remainder, int i)
{
  HOST_WIDE_INT temp1;
  int num_insns = 0;
  do
    {
      int end;

      if (i <= 0)
        i += 32;
      if (remainder & (3 << (i - 2)))
        {
          end = i - 8;
          if (end < 0)
            end += 32;
          temp1 = remainder & ((0x0ff << end)
                                    | ((i < end) ? (0xff >> (32 - end)) : 0));
          remainder &= ~temp1;
          num_insns++;
          i -= 6;
        }
      i -= 2;
    } while (remainder);
  return num_insns;
}

/* Emit an instruction with the indicated PATTERN.  If COND is
   non-NULL, conditionalize the execution of the instruction on COND
   being true.  */

static void
emit_constant_insn (rtx cond, rtx pattern)
{
  if (cond)
    pattern = gen_rtx_COND_EXEC (VOIDmode, copy_rtx (cond), pattern);
  emit_insn (pattern);
}

/* As above, but extra parameter GENERATE which, if clear, suppresses
   RTL generation.  */

static int
arm_gen_constant (enum rtx_code code, enum machine_mode mode, rtx cond,
                  HOST_WIDE_INT val, rtx target, rtx source, int subtargets,
                  int generate)
{
  int can_invert = 0;
  int can_negate = 0;
  int can_negate_initial = 0;
  int can_shift = 0;
  int i;
  int num_bits_set = 0;
  int set_sign_bit_copies = 0;
  int clear_sign_bit_copies = 0;
  int clear_zero_bit_copies = 0;
  int set_zero_bit_copies = 0;
  int insns = 0;
  unsigned HOST_WIDE_INT temp1, temp2;
  unsigned HOST_WIDE_INT remainder = val & 0xffffffff;

  /* Find out which operations are safe for a given CODE.  Also do a quick
     check for degenerate cases; these can occur when DImode operations
     are split.  */
  switch (code)
    {
    case SET:
      can_invert = 1;
      can_shift = 1;
      can_negate = 1;
      break;

    case PLUS:
      can_negate = 1;
      can_negate_initial = 1;
      break;

    case IOR:
      if (remainder == 0xffffffff)
        {
          if (generate)
            emit_constant_insn (cond,
                                gen_rtx_SET (VOIDmode, target,
                                             GEN_INT (ARM_SIGN_EXTEND (val))));
          return 1;
        }
      if (remainder == 0)
        {
          if (reload_completed && rtx_equal_p (target, source))
            return 0;
          if (generate)
            emit_constant_insn (cond,
                                gen_rtx_SET (VOIDmode, target, source));
          return 1;
        }
      break;

    case AND:
      if (remainder == 0)
        {
          if (generate)
            emit_constant_insn (cond,
                                gen_rtx_SET (VOIDmode, target, const0_rtx));
          return 1;
        }
      if (remainder == 0xffffffff)
        {
          if (reload_completed && rtx_equal_p (target, source))
            return 0;
          if (generate)
            emit_constant_insn (cond,
                                gen_rtx_SET (VOIDmode, target, source));
          return 1;
        }
      can_invert = 1;
      break;

    case XOR:
      if (remainder == 0)
        {
          if (reload_completed && rtx_equal_p (target, source))
            return 0;
          if (generate)
            emit_constant_insn (cond,
                                gen_rtx_SET (VOIDmode, target, source));
          return 1;
        }
      if (remainder == 0xffffffff)
        {
          if (generate)
            emit_constant_insn (cond,
                                gen_rtx_SET (VOIDmode, target,
                                             gen_rtx_NOT (mode, source)));
          return 1;
        }

      /* We don't know how to handle this yet below.  */
      abort ();

    case MINUS:
      /* We treat MINUS as (val - source), since (source - val) is always
         passed as (source + (-val)).  */
      if (remainder == 0)
        {
          if (generate)
            emit_constant_insn (cond,
                                gen_rtx_SET (VOIDmode, target,
                                             gen_rtx_NEG (mode, source)));
          return 1;
        }
      if (const_ok_for_arm (val))
        {
          if (generate)
            emit_constant_insn (cond,
                                gen_rtx_SET (VOIDmode, target,
                                             gen_rtx_MINUS (mode, GEN_INT (val),
                                                            source)));
          return 1;
        }
      can_negate = 1;

      break;

    default:
      abort ();
    }

  /* If we can do it in one insn get out quickly.  */
  if (const_ok_for_arm (val)
      || (can_negate_initial && const_ok_for_arm (-val))
      || (can_invert && const_ok_for_arm (~val)))
    {
      if (generate)
        emit_constant_insn (cond,
                            gen_rtx_SET (VOIDmode, target,
                                         (source
                                          ? gen_rtx_fmt_ee (code, mode, source,
                                                            GEN_INT (val))
                                          : GEN_INT (val))));
      return 1;
    }

  /* Calculate a few attributes that may be useful for specific
     optimizations.  */
  for (i = 31; i >= 0; i--)
    {
      if ((remainder & (1 << i)) == 0)
        clear_sign_bit_copies++;
      else
        break;
    }

  for (i = 31; i >= 0; i--)
    {
      if ((remainder & (1 << i)) != 0)
        set_sign_bit_copies++;
      else
        break;
    }

  for (i = 0; i <= 31; i++)
    {
      if ((remainder & (1 << i)) == 0)
        clear_zero_bit_copies++;
      else
        break;
    }

  for (i = 0; i <= 31; i++)
    {
      if ((remainder & (1 << i)) != 0)
        set_zero_bit_copies++;
      else
        break;
    }

  switch (code)
    {
    case SET:
      /* See if we can do this by sign_extending a constant that is known
         to be negative.  This is a good, way of doing it, since the shift
         may well merge into a subsequent insn.  */
      if (set_sign_bit_copies > 1)
        {
          if (const_ok_for_arm
              (temp1 = ARM_SIGN_EXTEND (remainder
                                        << (set_sign_bit_copies - 1))))
            {
              if (generate)
                {
                  rtx new_src = subtargets ? gen_reg_rtx (mode) : target;
                  emit_constant_insn (cond,
                                      gen_rtx_SET (VOIDmode, new_src,
                                                   GEN_INT (temp1)));
                  emit_constant_insn (cond,
                                      gen_ashrsi3 (target, new_src,
                                                   GEN_INT (set_sign_bit_copies - 1)));
                }
              return 2;
            }
          /* For an inverted constant, we will need to set the low bits,
             these will be shifted out of harm's way.  */
          temp1 |= (1 << (set_sign_bit_copies - 1)) - 1;
          if (const_ok_for_arm (~temp1))
            {
              if (generate)
                {
                  rtx new_src = subtargets ? gen_reg_rtx (mode) : target;
                  emit_constant_insn (cond,
                                      gen_rtx_SET (VOIDmode, new_src,
                                                   GEN_INT (temp1)));
                  emit_constant_insn (cond,
                                      gen_ashrsi3 (target, new_src,
                                                   GEN_INT (set_sign_bit_copies - 1)));
                }
              return 2;
            }
        }

      /* See if we can generate this by setting the bottom (or the top)
         16 bits, and then shifting these into the other half of the
         word.  We only look for the simplest cases, to do more would cost
         too much.  Be careful, however, not to generate this when the
         alternative would take fewer insns.  */
      if (val & 0xffff0000)
        {
          temp1 = remainder & 0xffff0000;
          temp2 = remainder & 0x0000ffff;

          /* Overlaps outside this range are best done using other methods.  */
          for (i = 9; i < 24; i++)
            {
              if ((((temp2 | (temp2 << i)) & 0xffffffff) == remainder)
                  && !const_ok_for_arm (temp2))
                {
                  rtx new_src = (subtargets
                                 ? (generate ? gen_reg_rtx (mode) : NULL_RTX)
                                 : target);
                  insns = arm_gen_constant (code, mode, cond, temp2, new_src,
                                            source, subtargets, generate);
                  source = new_src;
                  if (generate)
                    emit_constant_insn
                      (cond,
                       gen_rtx_SET
                       (VOIDmode, target,
                        gen_rtx_IOR (mode,
                                     gen_rtx_ASHIFT (mode, source,
                                                     GEN_INT (i)),
                                     source)));
                  return insns + 1;
                }
            }

          /* Don't duplicate cases already considered.  */
          for (i = 17; i < 24; i++)
            {
              if (((temp1 | (temp1 >> i)) == remainder)
                  && !const_ok_for_arm (temp1))
                {
                  rtx new_src = (subtargets
                                 ? (generate ? gen_reg_rtx (mode) : NULL_RTX)
                                 : target);
                  insns = arm_gen_constant (code, mode, cond, temp1, new_src,
                                            source, subtargets, generate);
                  source = new_src;
                  if (generate)
                    emit_constant_insn
                      (cond,
                       gen_rtx_SET (VOIDmode, target,
                                    gen_rtx_IOR
                                    (mode,
                                     gen_rtx_LSHIFTRT (mode, source,
                                                       GEN_INT (i)),
                                     source)));
                  return insns + 1;
                }
            }
        }
      break;

    case IOR:
    case XOR:
      /* If we have IOR or XOR, and the constant can be loaded in a
         single instruction, and we can find a temporary to put it in,
         then this can be done in two instructions instead of 3-4.  */
      if (subtargets
          /* TARGET can't be NULL if SUBTARGETS is 0 */
          || (reload_completed && !reg_mentioned_p (target, source)))
        {
          if (const_ok_for_arm (ARM_SIGN_EXTEND (~val)))
            {
              if (generate)
                {
                  rtx sub = subtargets ? gen_reg_rtx (mode) : target;

                  emit_constant_insn (cond,
                                      gen_rtx_SET (VOIDmode, sub,
                                                   GEN_INT (val)));
                  emit_constant_insn (cond,
                                      gen_rtx_SET (VOIDmode, target,
                                                   gen_rtx_fmt_ee (code, mode,
                                                                   source, sub)));
                }
              return 2;
            }
        }

      if (code == XOR)
        break;

      if (set_sign_bit_copies > 8
          && (val & (-1 << (32 - set_sign_bit_copies))) == val)
        {
          if (generate)
            {
              rtx sub = subtargets ? gen_reg_rtx (mode) : target;
              rtx shift = GEN_INT (set_sign_bit_copies);

              emit_constant_insn
                (cond,
                 gen_rtx_SET (VOIDmode, sub,
                              gen_rtx_NOT (mode,
                                           gen_rtx_ASHIFT (mode,
                                                           source,
                                                           shift))));
              emit_constant_insn
                (cond,
                 gen_rtx_SET (VOIDmode, target,
                              gen_rtx_NOT (mode,
                                           gen_rtx_LSHIFTRT (mode, sub,
                                                             shift))));
            }
          return 2;
        }

      if (set_zero_bit_copies > 8
          && (remainder & ((1 << set_zero_bit_copies) - 1)) == remainder)
        {
          if (generate)
            {
              rtx sub = subtargets ? gen_reg_rtx (mode) : target;
              rtx shift = GEN_INT (set_zero_bit_copies);

              emit_constant_insn
                (cond,
                 gen_rtx_SET (VOIDmode, sub,
                              gen_rtx_NOT (mode,
                                           gen_rtx_LSHIFTRT (mode,
                                                             source,
                                                             shift))));
              emit_constant_insn
                (cond,
                 gen_rtx_SET (VOIDmode, target,
                              gen_rtx_NOT (mode,
                                           gen_rtx_ASHIFT (mode, sub,
                                                           shift))));
            }
          return 2;
        }

      if (const_ok_for_arm (temp1 = ARM_SIGN_EXTEND (~val)))
        {
          if (generate)
            {
              rtx sub = subtargets ? gen_reg_rtx (mode) : target;
              emit_constant_insn (cond,
                                  gen_rtx_SET (VOIDmode, sub,
                                               gen_rtx_NOT (mode, source)));
              source = sub;
              if (subtargets)
                sub = gen_reg_rtx (mode);
              emit_constant_insn (cond,
                                  gen_rtx_SET (VOIDmode, sub,
                                               gen_rtx_AND (mode, source,
                                                            GEN_INT (temp1))));
              emit_constant_insn (cond,
                                  gen_rtx_SET (VOIDmode, target,
                                               gen_rtx_NOT (mode, sub)));
            }
          return 3;
        }
      break;

    case AND:
      /* See if two shifts will do 2 or more insn's worth of work.  */
      if (clear_sign_bit_copies >= 16 && clear_sign_bit_copies < 24)
        {
          HOST_WIDE_INT shift_mask = ((0xffffffff
                                       << (32 - clear_sign_bit_copies))
                                      & 0xffffffff);

          if ((remainder | shift_mask) != 0xffffffff)
            {
              if (generate)
                {
                  rtx new_src = subtargets ? gen_reg_rtx (mode) : target;
                  insns = arm_gen_constant (AND, mode, cond,
                                            remainder | shift_mask,
                                            new_src, source, subtargets, 1);
                  source = new_src;
                }
              else
                {
                  rtx targ = subtargets ? NULL_RTX : target;
                  insns = arm_gen_constant (AND, mode, cond,
                                            remainder | shift_mask,
                                            targ, source, subtargets, 0);
                }
            }

          if (generate)
            {
              rtx new_src = subtargets ? gen_reg_rtx (mode) : target;
              rtx shift = GEN_INT (clear_sign_bit_copies);

              emit_insn (gen_ashlsi3 (new_src, source, shift));
              emit_insn (gen_lshrsi3 (target, new_src, shift));
            }

          return insns + 2;
        }

      if (clear_zero_bit_copies >= 16 && clear_zero_bit_copies < 24)
        {
          HOST_WIDE_INT shift_mask = (1 << clear_zero_bit_copies) - 1;

          if ((remainder | shift_mask) != 0xffffffff)
            {
              if (generate)
                {
                  rtx new_src = subtargets ? gen_reg_rtx (mode) : target;

                  insns = arm_gen_constant (AND, mode, cond,
                                            remainder | shift_mask,
                                            new_src, source, subtargets, 1);
                  source = new_src;
                }
              else
                {
                  rtx targ = subtargets ? NULL_RTX : target;

                  insns = arm_gen_constant (AND, mode, cond,
                                            remainder | shift_mask,
                                            targ, source, subtargets, 0);
                }
            }

          if (generate)
            {
              rtx new_src = subtargets ? gen_reg_rtx (mode) : target;
              rtx shift = GEN_INT (clear_zero_bit_copies);

              emit_insn (gen_lshrsi3 (new_src, source, shift));
              emit_insn (gen_ashlsi3 (target, new_src, shift));
            }

          return insns + 2;
        }

      break;

    default:
      break;
    }

  for (i = 0; i < 32; i++)
    if (remainder & (1 << i))
      num_bits_set++;

  if (code == AND || (can_invert && num_bits_set > 16))
    remainder = (~remainder) & 0xffffffff;
  else if (code == PLUS && num_bits_set > 16)
    remainder = (-remainder) & 0xffffffff;
  else
    {
      can_invert = 0;
      can_negate = 0;
    }

  /* Now try and find a way of doing the job in either two or three
     instructions.
     We start by looking for the largest block of zeros that are aligned on
     a 2-bit boundary, we then fill up the temps, wrapping around to the
     top of the word when we drop off the bottom.
     In the worst case this code should produce no more than four insns.  */
  {
    int best_start = 0;
    int best_consecutive_zeros = 0;

    for (i = 0; i < 32; i += 2)
      {
        int consecutive_zeros = 0;

        if (!(remainder & (3 << i)))
          {
            while ((i < 32) && !(remainder & (3 << i)))
              {
                consecutive_zeros += 2;
                i += 2;
              }
            if (consecutive_zeros > best_consecutive_zeros)
              {
                best_consecutive_zeros = consecutive_zeros;
                best_start = i - consecutive_zeros;
              }
            i -= 2;
          }
      }

    /* So long as it won't require any more insns to do so, it's
       desirable to emit a small constant (in bits 0...9) in the last
       insn.  This way there is more chance that it can be combined with
       a later addressing insn to form a pre-indexed load or store
       operation.  Consider:

               *((volatile int *)0xe0000100) = 1;
               *((volatile int *)0xe0000110) = 2;

       We want this to wind up as:

                mov rA, #0xe0000000
                mov rB, #1
                str rB, [rA, #0x100]
                mov rB, #2
                str rB, [rA, #0x110]

       rather than having to synthesize both large constants from scratch.

       Therefore, we calculate how many insns would be required to emit
       the constant starting from `best_start', and also starting from
       zero (i.e. with bit 31 first to be output).  If `best_start' doesn't
       yield a shorter sequence, we may as well use zero.  */
    if (best_start != 0
        && ((((unsigned HOST_WIDE_INT) 1) << best_start) < remainder)
        && (count_insns_for_constant (remainder, 0) <=
            count_insns_for_constant (remainder, best_start)))
      best_start = 0;

    /* Now start emitting the insns.  */
    i = best_start;
    do
      {
        int end;

        if (i <= 0)
          i += 32;
        if (remainder & (3 << (i - 2)))
          {
            end = i - 8;
            if (end < 0)
              end += 32;
            temp1 = remainder & ((0x0ff << end)
                                 | ((i < end) ? (0xff >> (32 - end)) : 0));
            remainder &= ~temp1;

            if (generate)
              {
                rtx new_src, temp1_rtx;

                if (code == SET || code == MINUS)
                  {
                    new_src = (subtargets ? gen_reg_rtx (mode) : target);
                    if (can_invert && code != MINUS)
                      temp1 = ~temp1;
                  }
                else
                  {
                    if (remainder && subtargets)
                      new_src = gen_reg_rtx (mode);
                    else
                      new_src = target;
                    if (can_invert)
                      temp1 = ~temp1;
                    else if (can_negate)
                      temp1 = -temp1;
                  }

                temp1 = trunc_int_for_mode (temp1, mode);
                temp1_rtx = GEN_INT (temp1);

                if (code == SET)
                  ;
                else if (code == MINUS)
                  temp1_rtx = gen_rtx_MINUS (mode, temp1_rtx, source);
                else
                  temp1_rtx = gen_rtx_fmt_ee (code, mode, source, temp1_rtx);

                emit_constant_insn (cond,
                                    gen_rtx_SET (VOIDmode, new_src,
                                                 temp1_rtx));
                source = new_src;
              }

            if (code == SET)
              {
                can_invert = 0;
                code = PLUS;
              }
            else if (code == MINUS)
              code = PLUS;

            insns++;
            i -= 6;
          }
        i -= 2;
      }
    while (remainder);
  }

  return insns;
}

/* Canonicalize a comparison so that we are more likely to recognize it.
   This can be done for a few constant compares, where we can make the
   immediate value easier to load.  */

enum rtx_code
arm_canonicalize_comparison (enum rtx_code code, rtx * op1)
{
  unsigned HOST_WIDE_INT i = INTVAL (*op1);

  switch (code)
    {
    case EQ:
    case NE:
      return code;

    case GT:
    case LE:
      if (i != ((((unsigned HOST_WIDE_INT) 1) << (HOST_BITS_PER_WIDE_INT - 1)) - 1)
          && (const_ok_for_arm (i + 1) || const_ok_for_arm (-(i + 1))))
        {
          *op1 = GEN_INT (i + 1);
          return code == GT ? GE : LT;
        }
      break;

    case GE:
    case LT:
      if (i != (((unsigned HOST_WIDE_INT) 1) << (HOST_BITS_PER_WIDE_INT - 1))
          && (const_ok_for_arm (i - 1) || const_ok_for_arm (-(i - 1))))
        {
          *op1 = GEN_INT (i - 1);
          return code == GE ? GT : LE;
        }
      break;

    case GTU:
    case LEU:
      if (i != ~((unsigned HOST_WIDE_INT) 0)
          && (const_ok_for_arm (i + 1) || const_ok_for_arm (-(i + 1))))
        {
          *op1 = GEN_INT (i + 1);
          return code == GTU ? GEU : LTU;
        }
      break;

    case GEU:
    case LTU:
      if (i != 0
          && (const_ok_for_arm (i - 1) || const_ok_for_arm (-(i - 1))))
        {
          *op1 = GEN_INT (i - 1);
          return code == GEU ? GTU : LEU;
        }
      break;

    default:
      abort ();
    }

  return code;
}


/* Define how to find the value returned by a function.  */

rtx
arm_function_value(tree type, tree func ATTRIBUTE_UNUSED)
{
  enum machine_mode mode;
  int unsignedp ATTRIBUTE_UNUSED;
  rtx r ATTRIBUTE_UNUSED;

  mode = TYPE_MODE (type);
  /* Promote integer types.  */
  if (INTEGRAL_TYPE_P (type))
    PROMOTE_FUNCTION_MODE (mode, unsignedp, type);

  /* Promotes small structs returned in a register to full-word size
     for big-endian AAPCS.  */
  if (arm_return_in_msb (type))
    {
      HOST_WIDE_INT size = int_size_in_bytes (type);
      if (size % UNITS_PER_WORD != 0)
        {
          size += UNITS_PER_WORD - size % UNITS_PER_WORD;
          mode = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
        }
    }
  
  return LIBCALL_VALUE(mode);
}

/* Determine the amount of memory needed to store the possible return 
   registers of an untyped call.  */
int
arm_apply_result_size (void)
{
  int size = 16;

  if (TARGET_ARM)
    {
      if (TARGET_HARD_FLOAT_ABI)
        {
          if (TARGET_FPA)
            size += 12;
          if (TARGET_MAVERICK)
            size += 8;
        }
      if (TARGET_IWMMXT_ABI)
        size += 8;
    }

  return size;
}

/* Decide whether a type should be returned in memory (true)
   or in a register (false).  This is called by the macro
   RETURN_IN_MEMORY.  */
int
arm_return_in_memory (tree type)
{
  HOST_WIDE_INT size;

  if (!AGGREGATE_TYPE_P (type) &&
      !(TARGET_AAPCS_BASED && TREE_CODE (type) == COMPLEX_TYPE))
    /* All simple types are returned in registers.
       For AAPCS, complex types are treated the same as aggregates.  */
    return 0;

  size = int_size_in_bytes (type);

  if (arm_abi != ARM_ABI_APCS)
    {
      /* ATPCS and later return aggregate types in memory only if they are
         larger than a word (or are variable size).  */
      return (size < 0 || size > UNITS_PER_WORD);
    }

  /* For the arm-wince targets we choose to be compatible with Microsoft's
     ARM and Thumb compilers, which always return aggregates in memory.  */
#ifndef ARM_WINCE
  /* All structures/unions bigger than one word are returned in memory.
     Also catch the case where int_size_in_bytes returns -1.  In this case
     the aggregate is either huge or of variable size, and in either case
     we will want to return it via memory and not in a register.  */
  if (size < 0 || size > UNITS_PER_WORD)
    return 1;

  if (TREE_CODE (type) == RECORD_TYPE)
    {
      tree field;

      /* For a struct the APCS says that we only return in a register
         if the type is 'integer like' and every addressable element
         has an offset of zero.  For practical purposes this means
         that the structure can have at most one non bit-field element
         and that this element must be the first one in the structure.  */

      /* Find the first field, ignoring non FIELD_DECL things which will
         have been created by C++.  */
      for (field = TYPE_FIELDS (type);
           field && TREE_CODE (field) != FIELD_DECL;
           field = TREE_CHAIN (field))
        continue;

      if (field == NULL)
        return 0; /* An empty structure.  Allowed by an extension to ANSI C.  */

      /* Check that the first field is valid for returning in a register.  */

      /* ... Floats are not allowed */
      if (FLOAT_TYPE_P (TREE_TYPE (field)))
        return 1;

      /* ... Aggregates that are not themselves valid for returning in
         a register are not allowed.  */
      if (RETURN_IN_MEMORY (TREE_TYPE (field)))
        return 1;

      /* Now check the remaining fields, if any.  Only bitfields are allowed,
         since they are not addressable.  */
      for (field = TREE_CHAIN (field);
           field;
           field = TREE_CHAIN (field))
        {
          if (TREE_CODE (field) != FIELD_DECL)
            continue;

          if (!DECL_BIT_FIELD_TYPE (field))
            return 1;
        }

      return 0;
    }

  if (TREE_CODE (type) == UNION_TYPE)
    {
      tree field;

      /* Unions can be returned in registers if every element is
         integral, or can be returned in an integer register.  */
      for (field = TYPE_FIELDS (type);
           field;
           field = TREE_CHAIN (field))
        {
          if (TREE_CODE (field) != FIELD_DECL)
            continue;

          if (FLOAT_TYPE_P (TREE_TYPE (field)))
            return 1;

          if (RETURN_IN_MEMORY (TREE_TYPE (field)))
            return 1;
        }

      return 0;
    }
#endif /* not ARM_WINCE */

  /* Return all other types in memory.  */
  return 1;
}

/* Indicate whether or not words of a double are in big-endian order.  */

int
arm_float_words_big_endian (void)
{
  if (TARGET_MAVERICK)
    return 0;

  /* For FPA, float words are always big-endian.  For VFP, floats words
     follow the memory system mode.  */

  if (TARGET_FPA)
    {
      return 1;
    }

  if (TARGET_VFP)
    return (TARGET_BIG_END ? 1 : 0);

  return 1;
}

/* Initialize a variable CUM of type CUMULATIVE_ARGS
   for a call to a function whose data type is FNTYPE.
   For a library call, FNTYPE is NULL.  */
void
arm_init_cumulative_args (CUMULATIVE_ARGS *pcum, tree fntype,
                          rtx libname  ATTRIBUTE_UNUSED,
                          tree fndecl ATTRIBUTE_UNUSED)
{
  /* On the ARM, the offset starts at 0.  */
  pcum->nregs = ((fntype && aggregate_value_p (TREE_TYPE (fntype), fntype)) ? 1 : 0);
  pcum->iwmmxt_nregs = 0;
  pcum->can_split = true;

  pcum->call_cookie = CALL_NORMAL;

  if (TARGET_LONG_CALLS)
    pcum->call_cookie = CALL_LONG;

  /* Check for long call/short call attributes.  The attributes
     override any command line option.  */
  if (fntype)
    {
      if (lookup_attribute ("short_call", TYPE_ATTRIBUTES (fntype)))
        pcum->call_cookie = CALL_SHORT;
      else if (lookup_attribute ("long_call", TYPE_ATTRIBUTES (fntype)))
        pcum->call_cookie = CALL_LONG;
    }

  /* Varargs vectors are treated the same as long long.
     named_count avoids having to change the way arm handles 'named' */
  pcum->named_count = 0;
  pcum->nargs = 0;

  if (TARGET_REALLY_IWMMXT && fntype)
    {
      tree fn_arg;

      for (fn_arg = TYPE_ARG_TYPES (fntype);
           fn_arg;
           fn_arg = TREE_CHAIN (fn_arg))
        pcum->named_count += 1;

      if (! pcum->named_count)
        pcum->named_count = INT_MAX;
    }
}


/* Return true if mode/type need doubleword alignment.  */
bool
arm_needs_doubleword_align (enum machine_mode mode, tree type)
{
  return (GET_MODE_ALIGNMENT (mode) > PARM_BOUNDARY
          || (type && TYPE_ALIGN (type) > PARM_BOUNDARY));
}


/* Determine where to put an argument to a function.
   Value is zero to push the argument on the stack,
   or a hard register in which to store the argument.

   MODE is the argument's machine mode.
   TYPE is the data type of the argument (as a tree).
    This is null for libcalls where that information may
    not be available.
   CUM is a variable of type CUMULATIVE_ARGS which gives info about
    the preceding args and about the function being called.
   NAMED is nonzero if this argument is a named parameter
    (otherwise it is an extra parameter matching an ellipsis).  */

rtx
arm_function_arg (CUMULATIVE_ARGS *pcum, enum machine_mode mode,
                  tree type, int named)
{
  int nregs;

  /* Varargs vectors are treated the same as long long.
     named_count avoids having to change the way arm handles 'named' */
  if (TARGET_IWMMXT_ABI
      && arm_vector_mode_supported_p (mode)
      && pcum->named_count > pcum->nargs + 1)
    {
      if (pcum->iwmmxt_nregs <= 9)
        return gen_rtx_REG (mode, pcum->iwmmxt_nregs + FIRST_IWMMXT_REGNUM);
      else
        {
          pcum->can_split = false;
          return NULL_RTX;
        }
    }

  /* Put doubleword aligned quantities in even register pairs.  */
  if (pcum->nregs & 1
      && ARM_DOUBLEWORD_ALIGN
      && arm_needs_doubleword_align (mode, type))
    pcum->nregs++;

  if (mode == VOIDmode)
    /* Compute operand 2 of the call insn.  */
    return GEN_INT (pcum->call_cookie);

  /* Only allow splitting an arg between regs and memory if all preceding
     args were allocated to regs.  For args passed by reference we only count
     the reference pointer.  */
  if (pcum->can_split)
    nregs = 1;
  else
    nregs = ARM_NUM_REGS2 (mode, type);

  if (!named || pcum->nregs + nregs > NUM_ARG_REGS)
    return NULL_RTX;

  return gen_rtx_REG (mode, pcum->nregs);
}

static int
arm_arg_partial_bytes (CUMULATIVE_ARGS *pcum, enum machine_mode mode,
                       tree type, bool named ATTRIBUTE_UNUSED)
{
  int nregs = pcum->nregs;

  if (arm_vector_mode_supported_p (mode))
    return 0;

  if (NUM_ARG_REGS > nregs
      && (NUM_ARG_REGS < nregs + ARM_NUM_REGS2 (mode, type))
      && pcum->can_split)
    return (NUM_ARG_REGS - nregs) * UNITS_PER_WORD;

  return 0;
}

/* Variable sized types are passed by reference.  This is a GCC
   extension to the ARM ABI.  */

static bool
arm_pass_by_reference (CUMULATIVE_ARGS *cum ATTRIBUTE_UNUSED,
                       enum machine_mode mode ATTRIBUTE_UNUSED,
                       tree type, bool named ATTRIBUTE_UNUSED)
{
  return type && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST;
}
\f
/* Encode the current state of the #pragma [no_]long_calls.  */
typedef enum
{
  OFF,          /* No #pramgma [no_]long_calls is in effect.  */
  LONG,         /* #pragma long_calls is in effect.  */
  SHORT         /* #pragma no_long_calls is in effect.  */
} arm_pragma_enum;

static arm_pragma_enum arm_pragma_long_calls = OFF;

void
arm_pr_long_calls (struct cpp_reader * pfile ATTRIBUTE_UNUSED)
{
  arm_pragma_long_calls = LONG;
}

void
arm_pr_no_long_calls (struct cpp_reader * pfile ATTRIBUTE_UNUSED)
{
  arm_pragma_long_calls = SHORT;
}

void
arm_pr_long_calls_off (struct cpp_reader * pfile ATTRIBUTE_UNUSED)
{
  arm_pragma_long_calls = OFF;
}
\f
/* Table of machine attributes.  */
const struct attribute_spec arm_attribute_table[] =
{
  /* { name, min_len, max_len, decl_req, type_req, fn_type_req, handler } */
  /* Function calls made to this symbol must be done indirectly, because
     it may lie outside of the 26 bit addressing range of a normal function
     call.  */
  { "long_call",    0, 0, false, true,  true,  NULL },
  /* Whereas these functions are always known to reside within the 26 bit
     addressing range.  */
  { "short_call",   0, 0, false, true,  true,  NULL },
  /* Interrupt Service Routines have special prologue and epilogue requirements.  */
  { "isr",          0, 1, false, false, false, arm_handle_isr_attribute },
  { "interrupt",    0, 1, false, false, false, arm_handle_isr_attribute },
  { "naked",        0, 0, true,  false, false, arm_handle_fndecl_attribute },
#ifdef ARM_PE
  /* ARM/PE has three new attributes:
     interfacearm - ?
     dllexport - for exporting a function/variable that will live in a dll
     dllimport - for importing a function/variable from a dll

     Microsoft allows multiple declspecs in one __declspec, separating
     them with spaces.  We do NOT support this.  Instead, use __declspec
     multiple times.
  */
  { "dllimport",    0, 0, true,  false, false, NULL },
  { "dllexport",    0, 0, true,  false, false, NULL },
  { "interfacearm", 0, 0, true,  false, false, arm_handle_fndecl_attribute },
#elif TARGET_DLLIMPORT_DECL_ATTRIBUTES
  { "dllimport",    0, 0, false, false, false, handle_dll_attribute },
  { "dllexport",    0, 0, false, false, false, handle_dll_attribute },
  { "notshared",    0, 0, false, true, false, arm_handle_notshared_attribute },
#endif
  { NULL,           0, 0, false, false, false, NULL }
};

/* Handle an attribute requiring a FUNCTION_DECL;
   arguments as in struct attribute_spec.handler.  */
static tree
arm_handle_fndecl_attribute (tree *node, tree name, tree args ATTRIBUTE_UNUSED,
                             int flags ATTRIBUTE_UNUSED, bool *no_add_attrs)
{
  if (TREE_CODE (*node) != FUNCTION_DECL)
    {
      warning (0, "%qs attribute only applies to functions",
               IDENTIFIER_POINTER (name));
      *no_add_attrs = true;
    }

  return NULL_TREE;
}

/* Handle an "interrupt" or "isr" attribute;
   arguments as in struct attribute_spec.handler.  */
static tree
arm_handle_isr_attribute (tree *node, tree name, tree args, int flags,
                          bool *no_add_attrs)
{
  if (DECL_P (*node))
    {
      if (TREE_CODE (*node) != FUNCTION_DECL)
        {
          warning (0, "%qs attribute only applies to functions",
                   IDENTIFIER_POINTER (name));
          *no_add_attrs = true;
        }
      /* FIXME: the argument if any is checked for type attributes;
         should it be checked for decl ones?  */
    }
  else
    {
      if (TREE_CODE (*node) == FUNCTION_TYPE
          || TREE_CODE (*node) == METHOD_TYPE)
        {
          if (arm_isr_value (args) == ARM_FT_UNKNOWN)
            {
              warning (0, "%qs attribute ignored", IDENTIFIER_POINTER (name));
              *no_add_attrs = true;
            }
        }
      else if (TREE_CODE (*node) == POINTER_TYPE
               && (TREE_CODE (TREE_TYPE (*node)) == FUNCTION_TYPE
                   || TREE_CODE (TREE_TYPE (*node)) == METHOD_TYPE)
               && arm_isr_value (args) != ARM_FT_UNKNOWN)
        {
          *node = build_variant_type_copy (*node);
          TREE_TYPE (*node) = build_type_attribute_variant
            (TREE_TYPE (*node),
             tree_cons (name, args, TYPE_ATTRIBUTES (TREE_TYPE (*node))));
          *no_add_attrs = true;
        }
      else
        {
          /* Possibly pass this attribute on from the type to a decl.  */
          if (flags & ((int) ATTR_FLAG_DECL_NEXT
                       | (int) ATTR_FLAG_FUNCTION_NEXT
                       | (int) ATTR_FLAG_ARRAY_NEXT))
            {
              *no_add_attrs = true;
              return tree_cons (name, args, NULL_TREE);
            }
          else
            {
              warning (0, "%qs attribute ignored", IDENTIFIER_POINTER (name));
            }
        }
    }

  return NULL_TREE;
}

#if TARGET_DLLIMPORT_DECL_ATTRIBUTES
/* Handle the "notshared" attribute.  This attribute is another way of
   requesting hidden visibility.  ARM's compiler supports
   "__declspec(notshared)"; we support the same thing via an
   attribute.  */

static tree
arm_handle_notshared_attribute (tree *node, 
                                tree name ATTRIBUTE_UNUSED, 
                                tree args ATTRIBUTE_UNUSED, 
                                int flags ATTRIBUTE_UNUSED, 
                                bool *no_add_attrs)
{
  tree decl = TYPE_NAME (*node);

  if (decl)
    {
      DECL_VISIBILITY (decl) = VISIBILITY_HIDDEN;
      DECL_VISIBILITY_SPECIFIED (decl) = 1;
      *no_add_attrs = false;
    }
  return NULL_TREE;
}
#endif

/* Return 0 if the attributes for two types are incompatible, 1 if they
   are compatible, and 2 if they are nearly compatible (which causes a
   warning to be generated).  */
static int
arm_comp_type_attributes (tree type1, tree type2)
{
  int l1, l2, s1, s2;

  /* Check for mismatch of non-default calling convention.  */
  if (TREE_CODE (type1) != FUNCTION_TYPE)
    return 1;

  /* Check for mismatched call attributes.  */
  l1 = lookup_attribute ("long_call", TYPE_ATTRIBUTES (type1)) != NULL;
  l2 = lookup_attribute ("long_call", TYPE_ATTRIBUTES (type2)) != NULL;
  s1 = lookup_attribute ("short_call", TYPE_ATTRIBUTES (type1)) != NULL;
  s2 = lookup_attribute ("short_call", TYPE_ATTRIBUTES (type2)) != NULL;

  /* Only bother to check if an attribute is defined.  */
  if (l1 | l2 | s1 | s2)
    {
      /* If one type has an attribute, the other must have the same attribute.  */
      if ((l1 != l2) || (s1 != s2))
        return 0;

      /* Disallow mixed attributes.  */
      if ((l1 & s2) || (l2 & s1))
        return 0;
    }

  /* Check for mismatched ISR attribute.  */
  l1 = lookup_attribute ("isr", TYPE_ATTRIBUTES (type1)) != NULL;
  if (! l1)
    l1 = lookup_attribute ("interrupt", TYPE_ATTRIBUTES (type1)) != NULL;
  l2 = lookup_attribute ("isr", TYPE_ATTRIBUTES (type2)) != NULL;
  if (! l2)
    l1 = lookup_attribute ("interrupt", TYPE_ATTRIBUTES (type2)) != NULL;
  if (l1 != l2)
    return 0;

  return 1;
}

/*  Encode long_call or short_call attribute by prefixing
    symbol name in DECL with a special character FLAG.  */
void
arm_encode_call_attribute (tree decl, int flag)
{
  const char * str = XSTR (XEXP (DECL_RTL (decl), 0), 0);
  int          len = strlen (str);
  char *       newstr;

  /* Do not allow weak functions to be treated as short call.  */
  if (DECL_WEAK (decl) && flag == SHORT_CALL_FLAG_CHAR)
    return;

  newstr = alloca (len + 2);
  newstr[0] = flag;
  strcpy (newstr + 1, str);

  newstr = (char *) ggc_alloc_string (newstr, len + 1);
  XSTR (XEXP (DECL_RTL (decl), 0), 0) = newstr;
}

/*  Assigns default attributes to newly defined type.  This is used to
    set short_call/long_call attributes for function types of
    functions defined inside corresponding #pragma scopes.  */
static void
arm_set_default_type_attributes (tree type)
{
  /* Add __attribute__ ((long_call)) to all functions, when
     inside #pragma long_calls or __attribute__ ((short_call)),
     when inside #pragma no_long_calls.  */
  if (TREE_CODE (type) == FUNCTION_TYPE || TREE_CODE (type) == METHOD_TYPE)
    {
      tree type_attr_list, attr_name;
      type_attr_list = TYPE_ATTRIBUTES (type);

      if (arm_pragma_long_calls == LONG)
        attr_name = get_identifier ("long_call");
      else if (arm_pragma_long_calls == SHORT)
        attr_name = get_identifier ("short_call");
      else
        return;

      type_attr_list = tree_cons (attr_name, NULL_TREE, type_attr_list);
      TYPE_ATTRIBUTES (type) = type_attr_list;
    }
}
\f
/* Return 1 if the operand is a SYMBOL_REF for a function known to be
   defined within the current compilation unit.  If this cannot be
   determined, then 0 is returned.  */
static int
current_file_function_operand (rtx sym_ref)
{
  /* This is a bit of a fib.  A function will have a short call flag
     applied to its name if it has the short call attribute, or it has
     already been defined within the current compilation unit.  */
  if (ENCODED_SHORT_CALL_ATTR_P (XSTR (sym_ref, 0)))
    return 1;

  /* The current function is always defined within the current compilation
     unit.  If it s a weak definition however, then this may not be the real
     definition of the function, and so we have to say no.  */
  if (sym_ref == XEXP (DECL_RTL (current_function_decl), 0)
      && !DECL_WEAK (current_function_decl))
    return 1;

  /* We cannot make the determination - default to returning 0.  */
  return 0;
}

/* Return nonzero if a 32 bit "long_call" should be generated for
   this call.  We generate a long_call if the function:

        a.  has an __attribute__((long call))
     or b.  is within the scope of a #pragma long_calls
     or c.  the -mlong-calls command line switch has been specified
         .  and either:
                1. -ffunction-sections is in effect
             or 2. the current function has __attribute__ ((section))
             or 3. the target function has __attribute__ ((section))

   However we do not generate a long call if the function:

        d.  has an __attribute__ ((short_call))
     or e.  is inside the scope of a #pragma no_long_calls
     or f.  is defined within the current compilation unit.

   This function will be called by C fragments contained in the machine
   description file.  SYM_REF and CALL_COOKIE correspond to the matched
   rtl operands.  CALL_SYMBOL is used to distinguish between
   two different callers of the function.  It is set to 1 in the
   "call_symbol" and "call_symbol_value" patterns and to 0 in the "call"
   and "call_value" patterns.  This is because of the difference in the
   SYM_REFs passed by these patterns.  */
int
arm_is_longcall_p (rtx sym_ref, int call_cookie, int call_symbol)
{
  if (!call_symbol)
    {
      if (GET_CODE (sym_ref) != MEM)
        return 0;

      sym_ref = XEXP (sym_ref, 0);
    }

  if (GET_CODE (sym_ref) != SYMBOL_REF)
    return 0;

  if (call_cookie & CALL_SHORT)
    return 0;

  if (TARGET_LONG_CALLS)
    {
      if (flag_function_sections
          || DECL_SECTION_NAME (current_function_decl))
        /* c.3 is handled by the definition of the
           ARM_DECLARE_FUNCTION_SIZE macro.  */
        return 1;
    }

  if (current_file_function_operand (sym_ref))
    return 0;

  return (call_cookie & CALL_LONG)
    || ENCODED_LONG_CALL_ATTR_P (XSTR (sym_ref, 0))
    || TARGET_LONG_CALLS;
}

/* Return nonzero if it is ok to make a tail-call to DECL.  */
static bool
arm_function_ok_for_sibcall (tree decl, tree exp ATTRIBUTE_UNUSED)
{
  int call_type = TARGET_LONG_CALLS ? CALL_LONG : CALL_NORMAL;

  if (cfun->machine->sibcall_blocked)
    return false;

  /* Never tailcall something for which we have no decl, or if we
     are in Thumb mode.  */
  if (decl == NULL || TARGET_THUMB)
    return false;

  /* Get the calling method.  */
  if (lookup_attribute ("short_call", TYPE_ATTRIBUTES (TREE_TYPE (decl))))
    call_type = CALL_SHORT;
  else if (lookup_attribute ("long_call", TYPE_ATTRIBUTES (TREE_TYPE (decl))))
    call_type = CALL_LONG;

  /* Cannot tail-call to long calls, since these are out of range of
     a branch instruction.  However, if not compiling PIC, we know
     we can reach the symbol if it is in this compilation unit.  */
  if (call_type == CALL_LONG && (flag_pic || !TREE_ASM_WRITTEN (decl)))
    return false;

  /* If we are interworking and the function is not declared static
     then we can't tail-call it unless we know that it exists in this
     compilation unit (since it might be a Thumb routine).  */
  if (TARGET_INTERWORK && TREE_PUBLIC (decl) && !TREE_ASM_WRITTEN (decl))
    return false;

  /* Never tailcall from an ISR routine - it needs a special exit sequence.  */
  if (IS_INTERRUPT (arm_current_func_type ()))
    return false;

  /* Everything else is ok.  */
  return true;
}

\f
/* Addressing mode support functions.  */

/* Return nonzero if X is a legitimate immediate operand when compiling
   for PIC.  */
int
legitimate_pic_operand_p (rtx x)
{
  if (CONSTANT_P (x)
      && flag_pic
      && (GET_CODE (x) == SYMBOL_REF
          || (GET_CODE (x) == CONST
              && GET_CODE (XEXP (x, 0)) == PLUS
              && GET_CODE (XEXP (XEXP (x, 0), 0)) == SYMBOL_REF)))
    return 0;

  return 1;
}

rtx
legitimize_pic_address (rtx orig, enum machine_mode mode, rtx reg)
{
  if (GET_CODE (orig) == SYMBOL_REF
      || GET_CODE (orig) == LABEL_REF)
    {
#ifndef AOF_ASSEMBLER
      rtx pic_ref, address;
#endif
      rtx insn;
      int subregs = 0;

      if (reg == 0)
        {
          if (no_new_pseudos)
            abort ();
          else
            reg = gen_reg_rtx (Pmode);

          subregs = 1;
        }

#ifdef AOF_ASSEMBLER
      /* The AOF assembler can generate relocations for these directly, and
         understands that the PIC register has to be added into the offset.  */
      insn = emit_insn (gen_pic_load_addr_based (reg, orig));
#else
      if (subregs)
        address = gen_reg_rtx (Pmode);
      else
        address = reg;

      if (TARGET_ARM)
        emit_insn (gen_pic_load_addr_arm (address, orig));
      else
        emit_insn (gen_pic_load_addr_thumb (address, orig));

      if ((GET_CODE (orig) == LABEL_REF
           || (GET_CODE (orig) == SYMBOL_REF &&
               SYMBOL_REF_LOCAL_P (orig)))
          && NEED_GOT_RELOC)
        pic_ref = gen_rtx_PLUS (Pmode, pic_offset_table_rtx, address);
      else
        {
          pic_ref = gen_const_mem (Pmode,
                                   gen_rtx_PLUS (Pmode, pic_offset_table_rtx,
                                                 address));
        }

      insn = emit_move_insn (reg, pic_ref);
#endif
      current_function_uses_pic_offset_table = 1;
      /* Put a REG_EQUAL note on this insn, so that it can be optimized
         by loop.  */
      REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUAL, orig,
                                            REG_NOTES (insn));
      return reg;
    }
  else if (GET_CODE (orig) == CONST)
    {
      rtx base, offset;

      if (GET_CODE (XEXP (orig, 0)) == PLUS
          && XEXP (XEXP (orig, 0), 0) == pic_offset_table_rtx)
        return orig;

      if (reg == 0)
        {
          if (no_new_pseudos)
            abort ();
          else
            reg = gen_reg_rtx (Pmode);
        }

      if (GET_CODE (XEXP (orig, 0)) == PLUS)
        {
          base = legitimize_pic_address (XEXP (XEXP (orig, 0), 0), Pmode, reg);
          offset = legitimize_pic_address (XEXP (XEXP (orig, 0), 1), Pmode,
                                           base == reg ? 0 : reg);
        }
      else
        abort ();

      if (GET_CODE (offset) == CONST_INT)
        {
          /* The base register doesn't really matter, we only want to
             test the index for the appropriate mode.  */
          if (!arm_legitimate_index_p (mode, offset, SET, 0))
            {
              if (!no_new_pseudos)
                offset = force_reg (Pmode, offset);
              else
                abort ();
            }

          if (GET_CODE (offset) == CONST_INT)
            return plus_constant (base, INTVAL (offset));
        }

      if (GET_MODE_SIZE (mode) > 4
          && (GET_MODE_CLASS (mode) == MODE_INT
              || TARGET_SOFT_FLOAT))
        {
          emit_insn (gen_addsi3 (reg, base, offset));
          return reg;
        }

      return gen_rtx_PLUS (Pmode, base, offset);
    }

  return orig;
}


/* Find a spare low register to use during the prolog of a function.  */

static int
thumb_find_work_register (unsigned long pushed_regs_mask)
{
  int reg;

  /* Check the argument registers first as these are call-used.  The
     register allocation order means that sometimes r3 might be used
     but earlier argument registers might not, so check them all.  */
  for (reg = LAST_ARG_REGNUM; reg >= 0; reg --)
    if (!regs_ever_live[reg])
      return reg;

  /* Before going on to check the call-saved registers we can try a couple
     more ways of deducing that r3 is available.  The first is when we are
     pushing anonymous arguments onto the stack and we have less than 4
     registers worth of fixed arguments(*).  In this case r3 will be part of
     the variable argument list and so we can be sure that it will be
     pushed right at the start of the function.  Hence it will be available
     for the rest of the prologue.
     (*): ie current_function_pretend_args_size is greater than 0.  */
  if (cfun->machine->uses_anonymous_args
      && current_function_pretend_args_size > 0)
    return LAST_ARG_REGNUM;

  /* The other case is when we have fixed arguments but less than 4 registers
     worth.  In this case r3 might be used in the body of the function, but
     it is not being used to convey an argument into the function.  In theory
     we could just check current_function_args_size to see how many bytes are
     being passed in argument registers, but it seems that it is unreliable.
     Sometimes it will have the value 0 when in fact arguments are being
     passed.  (See testcase execute/20021111-1.c for an example).  So we also
     check the args_info.nregs field as well.  The problem with this field is
     that it makes no allowances for arguments that are passed to the
     function but which are not used.  Hence we could miss an opportunity
     when a function has an unused argument in r3.  But it is better to be
     safe than to be sorry.  */
  if (! cfun->machine->uses_anonymous_args
      && current_function_args_size >= 0
      && current_function_args_size <= (LAST_ARG_REGNUM * UNITS_PER_WORD)
      && cfun->args_info.nregs < 4)
    return LAST_ARG_REGNUM;
  
  /* Otherwise look for a call-saved register that is going to be pushed.  */
  for (reg = LAST_LO_REGNUM; reg > LAST_ARG_REGNUM; reg --)
    if (pushed_regs_mask & (1 << reg))
      return reg;

  /* Something went wrong - thumb_compute_save_reg_mask()
     should have arranged for a suitable register to be pushed.  */
  abort ();
}


/* Generate code to load the PIC register.  In thumb mode SCRATCH is a
   low register.  */

void
arm_load_pic_register (unsigned int scratch)
{
#ifndef AOF_ASSEMBLER
  rtx l1, pic_tmp, pic_tmp2, pic_rtx;
  rtx global_offset_table;

  if (current_function_uses_pic_offset_table == 0 || TARGET_SINGLE_PIC_BASE)
    return;

  if (!flag_pic)
    abort ();

  l1 = gen_label_rtx ();

  global_offset_table = gen_rtx_SYMBOL_REF (Pmode, "_GLOBAL_OFFSET_TABLE_");
  /* On the ARM the PC register contains 'dot + 8' at the time of the
     addition, on the Thumb it is 'dot + 4'.  */
  pic_tmp = plus_constant (gen_rtx_LABEL_REF (Pmode, l1), TARGET_ARM ? 8 : 4);
  if (GOT_PCREL)
    pic_tmp2 = gen_rtx_CONST (VOIDmode,
                            gen_rtx_PLUS (Pmode, global_offset_table, pc_rtx));
  else
    pic_tmp2 = gen_rtx_CONST (VOIDmode, global_offset_table);

  pic_rtx = gen_rtx_CONST (Pmode, gen_rtx_MINUS (Pmode, pic_tmp2, pic_tmp));

  if (TARGET_ARM)
    {
      emit_insn (gen_pic_load_addr_arm (pic_offset_table_rtx, pic_rtx));
      emit_insn (gen_pic_add_dot_plus_eight (pic_offset_table_rtx, l1));
    }
  else
    {
      if (REGNO (pic_offset_table_rtx) > LAST_LO_REGNUM)
        {
          /* We will have pushed the pic register, so should always be
             able to find a work register.  */
          pic_tmp = gen_rtx_REG (SImode, scratch);
          emit_insn (gen_pic_load_addr_thumb (pic_tmp, pic_rtx));
          emit_insn (gen_movsi (pic_offset_table_rtx, pic_tmp));
        }
      else
        emit_insn (gen_pic_load_addr_thumb (pic_offset_table_rtx, pic_rtx));
      emit_insn (gen_pic_add_dot_plus_four (pic_offset_table_rtx, l1));
    }

  /* Need to emit this whether or not we obey regdecls,
     since setjmp/longjmp can cause life info to screw up.  */
  emit_insn (gen_rtx_USE (VOIDmode, pic_offset_table_rtx));
#endif /* AOF_ASSEMBLER */
}


/* Return nonzero if X is valid as an ARM state addressing register.  */
static int
arm_address_register_rtx_p (rtx x, int strict_p)
{
  int regno;

  if (GET_CODE (x) != REG)
    return 0;

  regno = REGNO (x);

  if (strict_p)
    return ARM_REGNO_OK_FOR_BASE_P (regno);

  return (regno <= LAST_ARM_REGNUM
          || regno >= FIRST_PSEUDO_REGISTER
          || regno == FRAME_POINTER_REGNUM
          || regno == ARG_POINTER_REGNUM);
}

/* Return nonzero if X is a valid ARM state address operand.  */
int
arm_legitimate_address_p (enum machine_mode mode, rtx x, RTX_CODE outer,
                          int strict_p)
{
  bool use_ldrd;
  enum rtx_code code = GET_CODE (x);

  if (arm_address_register_rtx_p (x, strict_p))
    return 1;

  use_ldrd = (TARGET_LDRD
              && (mode == DImode
                  || (mode == DFmode && (TARGET_SOFT_FLOAT || TARGET_VFP))));

  if (code == POST_INC || code == PRE_DEC
      || ((code == PRE_INC || code == POST_DEC)
          && (use_ldrd || GET_MODE_SIZE (mode) <= 4)))
    return arm_address_register_rtx_p (XEXP (x, 0), strict_p);

  else if ((code == POST_MODIFY || code == PRE_MODIFY)
           && arm_address_register_rtx_p (XEXP (x, 0), strict_p)
           && GET_CODE (XEXP (x, 1)) == PLUS
           && rtx_equal_p (XEXP (XEXP (x, 1), 0), XEXP (x, 0)))
    {
      rtx addend = XEXP (XEXP (x, 1), 1);

      /* Don't allow ldrd post increment by register because it's hard
         to fixup invalid register choices.  */
      if (use_ldrd
          && GET_CODE (x) == POST_MODIFY
          && GET_CODE (addend) == REG)
        return 0;

      return ((use_ldrd || GET_MODE_SIZE (mode) <= 4)
              && arm_legitimate_index_p (mode, addend, outer, strict_p));
    }

  /* After reload constants split into minipools will have addresses
     from a LABEL_REF.  */
  else if (reload_completed
           && (code == LABEL_REF
               || (code == CONST
                   && GET_CODE (XEXP (x, 0)) == PLUS
                   && GET_CODE (XEXP (XEXP (x, 0), 0)) == LABEL_REF
                   && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)))
    return 1;

  else if (mode == TImode)
    return 0;

  else if (code == PLUS)
    {
      rtx xop0 = XEXP (x, 0);
      rtx xop1 = XEXP (x, 1);

      return ((arm_address_register_rtx_p (xop0, strict_p)
               && arm_legitimate_index_p (mode, xop1, outer, strict_p))
              || (arm_address_register_rtx_p (xop1, strict_p)
                  && arm_legitimate_index_p (mode, xop0, outer, strict_p)));
    }

#if 0
  /* Reload currently can't handle MINUS, so disable this for now */
  else if (GET_CODE (x) == MINUS)
    {
      rtx xop0 = XEXP (x, 0);
      rtx xop1 = XEXP (x, 1);

      return (arm_address_register_rtx_p (xop0, strict_p)
              && arm_legitimate_index_p (mode, xop1, outer, strict_p));
    }
#endif

  else if (GET_MODE_CLASS (mode) != MODE_FLOAT
           && code == SYMBOL_REF
           && CONSTANT_POOL_ADDRESS_P (x)
           && ! (flag_pic
                 && symbol_mentioned_p (get_pool_constant (x))))
    return 1;

  return 0;
}

/* Return nonzero if INDEX is valid for an address index operand in
   ARM state.  */
static int
arm_legitimate_index_p (enum machine_mode mode, rtx index, RTX_CODE outer,
                        int strict_p)
{
  HOST_WIDE_INT range;
  enum rtx_code code = GET_CODE (index);

  /* Standard coprocessor addressing modes.  */
  if (TARGET_HARD_FLOAT
      && (TARGET_FPA || TARGET_MAVERICK)
      && (GET_MODE_CLASS (mode) == MODE_FLOAT
          || (TARGET_MAVERICK && mode == DImode)))
    return (code == CONST_INT && INTVAL (index) < 1024
            && INTVAL (index) > -1024
            && (INTVAL (index) & 3) == 0);

  if (TARGET_REALLY_IWMMXT && VALID_IWMMXT_REG_MODE (mode))
    return (code == CONST_INT
            && INTVAL (index) < 1024
            && INTVAL (index) > -1024
            && (INTVAL (index) & 3) == 0);

  if (arm_address_register_rtx_p (index, strict_p)
      && (GET_MODE_SIZE (mode) <= 4))
    return 1;

  if (mode == DImode || mode == DFmode)
    {
      if (code == CONST_INT)
        {
          HOST_WIDE_INT val = INTVAL (index);

          if (TARGET_LDRD)
            return val > -256 && val < 256;
          else
            return val > -4096 && val < 4092;
        }

      return TARGET_LDRD && arm_address_register_rtx_p (index, strict_p);
    }

  if (GET_MODE_SIZE (mode) <= 4
      && ! (arm_arch4
            && (mode == HImode
                || (mode == QImode && outer == SIGN_EXTEND))))
    {
      if (code == MULT)
        {
          rtx xiop0 = XEXP (index, 0);
          rtx xiop1 = XEXP (index, 1);

          return ((arm_address_register_rtx_p (xiop0, strict_p)
                   && power_of_two_operand (xiop1, SImode))
                  || (arm_address_register_rtx_p (xiop1, strict_p)
                      && power_of_two_operand (xiop0, SImode)));
        }
      else if (code == LSHIFTRT || code == ASHIFTRT
               || code == ASHIFT || code == ROTATERT)
        {
          rtx op = XEXP (index, 1);

          return (arm_address_register_rtx_p (XEXP (index, 0), strict_p)
                  && GET_CODE (op) == CONST_INT
                  && INTVAL (op) > 0
                  && INTVAL (op) <= 31);
        }
    }

  /* For ARM v4 we may be doing a sign-extend operation during the
     load.  */
  if (arm_arch4)
    {
      if (mode == HImode || (outer == SIGN_EXTEND && mode == QImode))
        range = 256;
      else
        range = 4096;
    }
  else
    range = (mode == HImode) ? 4095 : 4096;

  return (code == CONST_INT
          && INTVAL (index) < range
          && INTVAL (index) > -range);
}

/* Return nonzero if X is valid as a Thumb state base register.  */
static int
thumb_base_register_rtx_p (rtx x, enum machine_mode mode, int strict_p)
{
  int regno;

  if (GET_CODE (x) != REG)
    return 0;

  regno = REGNO (x);

  if (strict_p)
    return THUMB_REGNO_MODE_OK_FOR_BASE_P (regno, mode);

  return (regno <= LAST_LO_REGNUM
          || regno > LAST_VIRTUAL_REGISTER
          || regno == FRAME_POINTER_REGNUM
          || (GET_MODE_SIZE (mode) >= 4
              && (regno == STACK_POINTER_REGNUM
                  || regno >= FIRST_PSEUDO_REGISTER
                  || x == hard_frame_pointer_rtx
                  || x == arg_pointer_rtx)));
}

/* Return nonzero if x is a legitimate index register.  This is the case
   for any base register that can access a QImode object.  */
inline static int
thumb_index_register_rtx_p (rtx x, int strict_p)
{
  return thumb_base_register_rtx_p (x, QImode, strict_p);
}

/* Return nonzero if x is a legitimate Thumb-state address.

   The AP may be eliminated to either the SP or the FP, so we use the
   least common denominator, e.g. SImode, and offsets from 0 to 64.

   ??? Verify whether the above is the right approach.

   ??? Also, the FP may be eliminated to the SP, so perhaps that
   needs special handling also.

   ??? Look at how the mips16 port solves this problem.  It probably uses
   better ways to solve some of these problems.

   Although it is not incorrect, we don't accept QImode and HImode
   addresses based on the frame pointer or arg pointer until the
   reload pass starts.  This is so that eliminating such addresses
   into stack based ones won't produce impossible code.  */
int
thumb_legitimate_address_p (enum machine_mode mode, rtx x, int strict_p)
{
  /* ??? Not clear if this is right.  Experiment.  */
  if (GET_MODE_SIZE (mode) < 4
      && !(reload_in_progress || reload_completed)
      && (reg_mentioned_p (frame_pointer_rtx, x)
          || reg_mentioned_p (arg_pointer_rtx, x)
          || reg_mentioned_p (virtual_incoming_args_rtx, x)
          || reg_mentioned_p (virtual_outgoing_args_rtx, x)
          || reg_mentioned_p (virtual_stack_dynamic_rtx, x)
          || reg_mentioned_p (virtual_stack_vars_rtx, x)))
    return 0;

  /* Accept any base register.  SP only in SImode or larger.  */
  else if (thumb_base_register_rtx_p (x, mode, strict_p))
    return 1;

  /* This is PC relative data before arm_reorg runs.  */
  else if (GET_MODE_SIZE (mode) >= 4 && CONSTANT_P (x)
           && GET_CODE (x) == SYMBOL_REF
           && CONSTANT_POOL_ADDRESS_P (x) && ! flag_pic)
    return 1;

  /* This is PC relative data after arm_reorg runs.  */
  else if (GET_MODE_SIZE (mode) >= 4 && reload_completed
           && (GET_CODE (x) == LABEL_REF
               || (GET_CODE (x) == CONST
                   && GET_CODE (XEXP (x, 0)) == PLUS
                   && GET_CODE (XEXP (XEXP (x, 0), 0)) == LABEL_REF
                   && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)))
    return 1;

  /* Post-inc indexing only supported for SImode and larger.  */
  else if (GET_CODE (x) == POST_INC && GET_MODE_SIZE (mode) >= 4
           && thumb_index_register_rtx_p (XEXP (x, 0), strict_p))
    return 1;

  else if (GET_CODE (x) == PLUS)
    {
      /* REG+REG address can be any two index registers.  */
      /* We disallow FRAME+REG addressing since we know that FRAME
         will be replaced with STACK, and SP relative addressing only
         permits SP+OFFSET.  */
      if (GET_MODE_SIZE (mode) <= 4
          && XEXP (x, 0) != frame_pointer_rtx
          && XEXP (x, 1) != frame_pointer_rtx
          && thumb_index_register_rtx_p (XEXP (x, 0), strict_p)
          && thumb_index_register_rtx_p (XEXP (x, 1), strict_p))
        return 1;

      /* REG+const has 5-7 bit offset for non-SP registers.  */
      else if ((thumb_index_register_rtx_p (XEXP (x, 0), strict_p)
                || XEXP (x, 0) == arg_pointer_rtx)
               && GET_CODE (XEXP (x, 1)) == CONST_INT
               && thumb_legitimate_offset_p (mode, INTVAL (XEXP (x, 1))))
        return 1;

      /* REG+const has 10 bit offset for SP, but only SImode and
         larger is supported.  */
      /* ??? Should probably check for DI/DFmode overflow here
         just like GO_IF_LEGITIMATE_OFFSET does.  */
      else if (GET_CODE (XEXP (x, 0)) == REG
               && REGNO (XEXP (x, 0)) == STACK_POINTER_REGNUM
               && GET_MODE_SIZE (mode) >= 4
               && GET_CODE (XEXP (x, 1)) == CONST_INT
               && INTVAL (XEXP (x, 1)) >= 0
               && INTVAL (XEXP (x, 1)) + GET_MODE_SIZE (mode) <= 1024
               && (INTVAL (XEXP (x, 1)) & 3) == 0)
        return 1;

      else if (GET_CODE (XEXP (x, 0)) == REG
               && REGNO (XEXP (x, 0)) == FRAME_POINTER_REGNUM
               && GET_MODE_SIZE (mode) >= 4
               && GET_CODE (XEXP (x, 1)) == CONST_INT
               && (INTVAL (XEXP (x, 1)) & 3) == 0)
        return 1;
    }

  else if (GET_MODE_CLASS (mode) != MODE_FLOAT
           && GET_MODE_SIZE (mode) == 4
           && GET_CODE (x) == SYMBOL_REF
           && CONSTANT_POOL_ADDRESS_P (x)
           && !(flag_pic
                && symbol_mentioned_p (get_pool_constant (x))))
    return 1;

  return 0;
}

/* Return nonzero if VAL can be used as an offset in a Thumb-state address
   instruction of mode MODE.  */
int
thumb_legitimate_offset_p (enum machine_mode mode, HOST_WIDE_INT val)
{
  switch (GET_MODE_SIZE (mode))
    {
    case 1:
      return val >= 0 && val < 32;

    case 2:
      return val >= 0 && val < 64 && (val & 1) == 0;

    default:
      return (val >= 0
              && (val + GET_MODE_SIZE (mode)) <= 128
              && (val & 3) == 0);
    }
}

/* Try machine-dependent ways of modifying an illegitimate address
   to be legitimate.  If we find one, return the new, valid address.  */
rtx
arm_legitimize_address (rtx x, rtx orig_x, enum machine_mode mode)
{
  if (GET_CODE (x) == PLUS)
    {
      rtx xop0 = XEXP (x, 0);
      rtx xop1 = XEXP (x, 1);

      if (CONSTANT_P (xop0) && !symbol_mentioned_p (xop0))
        xop0 = force_reg (SImode, xop0);

      if (CONSTANT_P (xop1) && !symbol_mentioned_p (xop1))
        xop1 = force_reg (SImode, xop1);

      if (ARM_BASE_REGISTER_RTX_P (xop0)
          && GET_CODE (xop1) == CONST_INT)
        {
          HOST_WIDE_INT n, low_n;
          rtx base_reg, val;
          n = INTVAL (xop1);

          /* VFP addressing modes actually allow greater offsets, but for
             now we just stick with the lowest common denominator.  */
          if (mode == DImode
              || ((TARGET_SOFT_FLOAT || TARGET_VFP) && mode == DFmode))
            {
              low_n = n & 0x0f;
              n &= ~0x0f;
              if (low_n > 4)
                {
                  n += 16;
                  low_n -= 16;
                }
            }
          else
            {
              low_n = ((mode) == TImode ? 0
                       : n >= 0 ? (n & 0xfff) : -((-n) & 0xfff));
              n -= low_n;
            }

          base_reg = gen_reg_rtx (SImode);
          val = force_operand (gen_rtx_PLUS (SImode, xop0,
                                             GEN_INT (n)), NULL_RTX);
          emit_move_insn (base_reg, val);
          x = (low_n == 0 ? base_reg
               : gen_rtx_PLUS (SImode, base_reg, GEN_INT (low_n)));
        }
      else if (xop0 != XEXP (x, 0) || xop1 != XEXP (x, 1))
        x = gen_rtx_PLUS (SImode, xop0, xop1);
    }

  /* XXX We don't allow MINUS any more -- see comment in
     arm_legitimate_address_p ().  */
  else if (GET_CODE (x) == MINUS)
    {
      rtx xop0 = XEXP (x, 0);
      rtx xop1 = XEXP (x, 1);

      if (CONSTANT_P (xop0))
        xop0 = force_reg (SImode, xop0);

      if (CONSTANT_P (xop1) && ! symbol_mentioned_p (xop1))
        xop1 = force_reg (SImode, xop1);

      if (xop0 != XEXP (x, 0) || xop1 != XEXP (x, 1))
        x = gen_rtx_MINUS (SImode, xop0, xop1);
    }

  if (flag_pic)
    {
      /* We need to find and carefully transform any SYMBOL and LABEL
         references; so go back to the original address expression.  */
      rtx new_x = legitimize_pic_address (orig_x, mode, NULL_RTX);

      if (new_x != orig_x)
        x = new_x;
    }

  return x;
}


/* Try machine-dependent ways of modifying an illegitimate Thumb address
   to be legitimate.  If we find one, return the new, valid address.  */
rtx
thumb_legitimize_address (rtx x, rtx orig_x, enum machine_mode mode)
{
  if (GET_CODE (x) == PLUS
      && GET_CODE (XEXP (x, 1)) == CONST_INT
      && (INTVAL (XEXP (x, 1)) >= 32 * GET_MODE_SIZE (mode)
          || INTVAL (XEXP (x, 1)) < 0))
    {
      rtx xop0 = XEXP (x, 0);
      rtx xop1 = XEXP (x, 1);
      HOST_WIDE_INT offset = INTVAL (xop1);

      /* Try and fold the offset into a biasing of the base register and
         then offsetting that.  Don't do this when optimizing for space
         since it can cause too many CSEs.  */
      if (optimize_size && offset >= 0
          && offset < 256 + 31 * GET_MODE_SIZE (mode))
        {
          HOST_WIDE_INT delta;

          if (offset >= 256)
            delta = offset - (256 - GET_MODE_SIZE (mode));
          else if (offset < 32 * GET_MODE_SIZE (mode) + 8)
            delta = 31 * GET_MODE_SIZE (mode);
          else
            delta = offset & (~31 * GET_MODE_SIZE (mode));

          xop0 = force_operand (plus_constant (xop0, offset - delta),
                                NULL_RTX);
          x = plus_constant (xop0, delta);
        }
      else if (offset < 0 && offset > -256)
        /* Small negative offsets are best done with a subtract before the
           dereference, forcing these into a register normally takes two
           instructions.  */
        x = force_operand (x, NULL_RTX);
      else
        {
          /* For the remaining cases, force the constant into a register.  */
          xop1 = force_reg (SImode, xop1);
          x = gen_rtx_PLUS (SImode, xop0, xop1);
        }
    }
  else if (GET_CODE (x) == PLUS
           && s_register_operand (XEXP (x, 1), SImode)
           && !s_register_operand (XEXP (x, 0), SImode))
    {
      rtx xop0 = force_operand (XEXP (x, 0), NULL_RTX);

      x = gen_rtx_PLUS (SImode, xop0, XEXP (x, 1));
    }

  if (flag_pic)
    {
      /* We need to find and carefully transform any SYMBOL and LABEL
         references; so go back to the original address expression.  */
      rtx new_x = legitimize_pic_address (orig_x, mode, NULL_RTX);

      if (new_x != orig_x)
        x = new_x;
    }

  return x;
}

\f

#define REG_OR_SUBREG_REG(X)                                            \
  (GET_CODE (X) == REG                                                  \
   || (GET_CODE (X) == SUBREG && GET_CODE (SUBREG_REG (X)) == REG))

#define REG_OR_SUBREG_RTX(X)                    \
   (GET_CODE (X) == REG ? (X) : SUBREG_REG (X))

#ifndef COSTS_N_INSNS
#define COSTS_N_INSNS(N) ((N) * 4 - 2)
#endif
static inline int
thumb_rtx_costs (rtx x, enum rtx_code code, enum rtx_code outer)
{
  enum machine_mode mode = GET_MODE (x);

  switch (code)
    {
    case ASHIFT:
    case ASHIFTRT:
    case LSHIFTRT:
    case ROTATERT:
    case PLUS:
    case MINUS:
    case COMPARE:
    case NEG:
    case NOT:
      return COSTS_N_INSNS (1);

    case MULT:
      if (GET_CODE (XEXP (x, 1)) == CONST_INT)
        {
          int cycles = 0;
          unsigned HOST_WIDE_INT i = INTVAL (XEXP (x, 1));

          while (i)
            {
              i >>= 2;
              cycles++;
            }
          return COSTS_N_INSNS (2) + cycles;
        }
      return COSTS_N_INSNS (1) + 16;

    case SET:
      return (COSTS_N_INSNS (1)
              + 4 * ((GET_CODE (SET_SRC (x)) == MEM)
                     + GET_CODE (SET_DEST (x)) == MEM));

    case CONST_INT:
      if (outer == SET)
        {
          if ((unsigned HOST_WIDE_INT) INTVAL (x) < 256)
            return 0;
          if (thumb_shiftable_const (INTVAL (x)))
            return COSTS_N_INSNS (2);
          return COSTS_N_INSNS (3);
        }
      else if ((outer == PLUS || outer == COMPARE)
               && INTVAL (x) < 256 && INTVAL (x) > -256)
        return 0;
      else if (outer == AND
               && INTVAL (x) < 256 && INTVAL (x) >= -256)
        return COSTS_N_INSNS (1);
      else if (outer == ASHIFT || outer == ASHIFTRT
               || outer == LSHIFTRT)
        return 0;
      return COSTS_N_INSNS (2);

    case CONST:
    case CONST_DOUBLE:
    case LABEL_REF:
    case SYMBOL_REF:
      return COSTS_N_INSNS (3);

    case UDIV:
    case UMOD:
    case DIV:
    case MOD:
      return 100;

    case TRUNCATE:
      return 99;

    case AND:
    case XOR:
    case IOR:
      /* XXX guess.  */
      return 8;

    case MEM:
      /* XXX another guess.  */
      /* Memory costs quite a lot for the first word, but subsequent words
         load at the equivalent of a single insn each.  */
      return (10 + 4 * ((GET_MODE_SIZE (mode) - 1) / UNITS_PER_WORD)
              + ((GET_CODE (x) == SYMBOL_REF && CONSTANT_POOL_ADDRESS_P (x))
                 ? 4 : 0));

    case IF_THEN_ELSE:
      /* XXX a guess.  */
      if (GET_CODE (XEXP (x, 1)) == PC || GET_CODE (XEXP (x, 2)) == PC)
        return 14;
      return 2;

    case ZERO_EXTEND:
      /* XXX still guessing.  */
      switch (GET_MODE (XEXP (x, 0)))
        {
        case QImode:
          return (1 + (mode == DImode ? 4 : 0)
                  + (GET_CODE (XEXP (x, 0)) == MEM ? 10 : 0));

        case HImode:
          return (4 + (mode == DImode ? 4 : 0)
                  + (GET_CODE (XEXP (x, 0)) == MEM ? 10 : 0));

        case SImode:
          return (1 + (GET_CODE (XEXP (x, 0)) == MEM ? 10 : 0));

        default:
          return 99;
        }

    default:
      return 99;
    }
}


/* Worker routine for arm_rtx_costs.  */
static inline int
arm_rtx_costs_1 (rtx x, enum rtx_code code, enum rtx_code outer)
{
  enum machine_mode mode = GET_MODE (x);
  enum rtx_code subcode;
  int extra_cost;

  switch (code)
    {
    case MEM:
      /* Memory costs quite a lot for the first word, but subsequent words
         load at the equivalent of a single insn each.  */
      return (10 + 4 * ((GET_MODE_SIZE (mode) - 1) / UNITS_PER_WORD)
              + (GET_CODE (x) == SYMBOL_REF
                 && CONSTANT_POOL_ADDRESS_P (x) ? 4 : 0));

    case DIV:
    case MOD:
    case UDIV:
    case UMOD:
      return optimize_size ? COSTS_N_INSNS (2) : 100;

    case ROTATE:
      if (mode == SImode && GET_CODE (XEXP (x, 1)) == REG)
        return 4;
      /* Fall through */
    case ROTATERT:
      if (mode != SImode)
        return 8;
      /* Fall through */
    case ASHIFT: case LSHIFTRT: case ASHIFTRT:
      if (mode == DImode)
        return (8 + (GET_CODE (XEXP (x, 1)) == CONST_INT ? 0 : 8)
                + ((GET_CODE (XEXP (x, 0)) == REG
                    || (GET_CODE (XEXP (x, 0)) == SUBREG
                        && GET_CODE (SUBREG_REG (XEXP (x, 0))) == REG))
                   ? 0 : 8));
      return (1 + ((GET_CODE (XEXP (x, 0)) == REG
                    || (GET_CODE (XEXP (x, 0)) == SUBREG
                        && GET_CODE (SUBREG_REG (XEXP (x, 0))) == REG))
                   ? 0 : 4)
              + ((GET_CODE (XEXP (x, 1)) == REG
                  || (GET_CODE (XEXP (x, 1)) == SUBREG
                      && GET_CODE (SUBREG_REG (XEXP (x, 1))) == REG)
                  || (GET_CODE (XEXP (x, 1)) == CONST_INT))
                 ? 0 : 4));

    case MINUS:
      if (mode == DImode)
        return (4 + (REG_OR_SUBREG_REG (XEXP (x, 1)) ? 0 : 8)
                + ((REG_OR_SUBREG_REG (XEXP (x, 0))
                    || (GET_CODE (XEXP (x, 0)) == CONST_INT
                       && const_ok_for_arm (INTVAL (XEXP (x, 0)))))
                   ? 0 : 8));

      if (GET_MODE_CLASS (mode) == MODE_FLOAT)
        return (2 + ((REG_OR_SUBREG_REG (XEXP (x, 1))
                      || (GET_CODE (XEXP (x, 1)) == CONST_DOUBLE
                          && arm_const_double_rtx (XEXP (x, 1))))
                     ? 0 : 8)
                + ((REG_OR_SUBREG_REG (XEXP (x, 0))
                    || (GET_CODE (XEXP (x, 0)) == CONST_DOUBLE
                        && arm_const_double_rtx (XEXP (x, 0))))
                   ? 0 : 8));

      if (((GET_CODE (XEXP (x, 0)) == CONST_INT
            && const_ok_for_arm (INTVAL (XEXP (x, 0)))
            && REG_OR_SUBREG_REG (XEXP (x, 1))))
          || (((subcode = GET_CODE (XEXP (x, 1))) == ASHIFT
               || subcode == ASHIFTRT || subcode == LSHIFTRT
               || subcode == ROTATE || subcode == ROTATERT
               || (subcode == MULT
                   && GET_CODE (XEXP (XEXP (x, 1), 1)) == CONST_INT
                   && ((INTVAL (XEXP (XEXP (x, 1), 1)) &
                        (INTVAL (XEXP (XEXP (x, 1), 1)) - 1)) == 0)))
              && REG_OR_SUBREG_REG (XEXP (XEXP (x, 1), 0))
              && (REG_OR_SUBREG_REG (XEXP (XEXP (x, 1), 1))
                  || GET_CODE (XEXP (XEXP (x, 1), 1)) == CONST_INT)
              && REG_OR_SUBREG_REG (XEXP (x, 0))))
        return 1;
      /* Fall through */

    case PLUS:
      if (GET_MODE_CLASS (mode) == MODE_FLOAT)
        return (2 + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : 8)
                + ((REG_OR_SUBREG_REG (XEXP (x, 1))
                    || (GET_CODE (XEXP (x, 1)) == CONST_DOUBLE
                        && arm_const_double_rtx (XEXP (x, 1))))
                   ? 0 : 8));

      /* Fall through */
    case AND: case XOR: case IOR:
      extra_cost = 0;

      /* Normally the frame registers will be spilt into reg+const during
         reload, so it is a bad idea to combine them with other instructions,
         since then they might not be moved outside of loops.  As a compromise
         we allow integration with ops that have a constant as their second
         operand.  */
      if ((REG_OR_SUBREG_REG (XEXP (x, 0))
           && ARM_FRAME_RTX (REG_OR_SUBREG_RTX (XEXP (x, 0)))
           && GET_CODE (XEXP (x, 1)) != CONST_INT)
          || (REG_OR_SUBREG_REG (XEXP (x, 0))
              && ARM_FRAME_RTX (REG_OR_SUBREG_RTX (XEXP (x, 0)))))
        extra_cost = 4;

      if (mode == DImode)
        return (4 + extra_cost + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : 8)
                + ((REG_OR_SUBREG_REG (XEXP (x, 1))
                    || (GET_CODE (XEXP (x, 1)) == CONST_INT
                        && const_ok_for_op (INTVAL (XEXP (x, 1)), code)))
                   ? 0 : 8));

      if (REG_OR_SUBREG_REG (XEXP (x, 0)))
        return (1 + (GET_CODE (XEXP (x, 1)) == CONST_INT ? 0 : extra_cost)
                + ((REG_OR_SUBREG_REG (XEXP (x, 1))
                    || (GET_CODE (XEXP (x, 1)) == CONST_INT
                        && const_ok_for_op (INTVAL (XEXP (x, 1)), code)))
                   ? 0 : 4));

      else if (REG_OR_SUBREG_REG (XEXP (x, 1)))
        return (1 + extra_cost
                + ((((subcode = GET_CODE (XEXP (x, 0))) == ASHIFT
                     || subcode == LSHIFTRT || subcode == ASHIFTRT
                     || subcode == ROTATE || subcode == ROTATERT
                     || (subcode == MULT
                         && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT
                         && ((INTVAL (XEXP (XEXP (x, 0), 1)) &
                              (INTVAL (XEXP (XEXP (x, 0), 1)) - 1)) == 0)))
                    && (REG_OR_SUBREG_REG (XEXP (XEXP (x, 0), 0)))
                    && ((REG_OR_SUBREG_REG (XEXP (XEXP (x, 0), 1)))
                        || GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
                   ? 0 : 4));

      return 8;

    case MULT:
      /* This should have been handled by the CPU specific routines.  */
      abort ();

    case TRUNCATE:
      if (arm_arch3m && mode == SImode
          && GET_CODE (XEXP (x, 0)) == LSHIFTRT
          && GET_CODE (XEXP (XEXP (x, 0), 0)) == MULT
          && (GET_CODE (XEXP (XEXP (XEXP (x, 0), 0), 0))
              == GET_CODE (XEXP (XEXP (XEXP (x, 0), 0), 1)))
          && (GET_CODE (XEXP (XEXP (XEXP (x, 0), 0), 0)) == ZERO_EXTEND
              || GET_CODE (XEXP (XEXP (XEXP (x, 0), 0), 0)) == SIGN_EXTEND))
        return 8;
      return 99;

    case NEG:
      if (GET_MODE_CLASS (mode) == MODE_FLOAT)
        return 4 + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : 6);
      /* Fall through */
    case NOT:
      if (mode == DImode)
        return 4 + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : 4);

      return 1 + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : 4);

    case IF_THEN_ELSE:
      if (GET_CODE (XEXP (x, 1)) == PC || GET_CODE (XEXP (x, 2)) == PC)
        return 14;
      return 2;

    case COMPARE:
      return 1;

    case ABS:
      return 4 + (mode == DImode ? 4 : 0);

    case SIGN_EXTEND:
      if (GET_MODE (XEXP (x, 0)) == QImode)
        return (4 + (mode == DImode ? 4 : 0)
                + (GET_CODE (XEXP (x, 0)) == MEM ? 10 : 0));
      /* Fall through */
    case ZERO_EXTEND:
      switch (GET_MODE (XEXP (x, 0)))
        {
        case QImode:
          return (1 + (mode == DImode ? 4 : 0)
                  + (GET_CODE (XEXP (x, 0)) == MEM ? 10 : 0));

        case HImode:
          return (4 + (mode == DImode ? 4 : 0)
                  + (GET_CODE (XEXP (x, 0)) == MEM ? 10 : 0));

        case SImode:
          return (1 + (GET_CODE (XEXP (x, 0)) == MEM ? 10 : 0));

        case V8QImode:
        case V4HImode:
        case V2SImode:
        case V4QImode:
        case V2HImode:
            return 1;

        default:
          break;
        }
      abort ();

    case CONST_INT:
      if (const_ok_for_arm (INTVAL (x)))
        return outer == SET ? 2 : -1;
      else if (outer == AND
               && const_ok_for_arm (~INTVAL (x)))
        return -1;
      else if ((outer == COMPARE
                || outer == PLUS || outer == MINUS)
               && const_ok_for_arm (-INTVAL (x)))
        return -1;
      else
        return 5;

    case CONST:
    case LABEL_REF:
    case SYMBOL_REF:
      return 6;

    case CONST_DOUBLE:
      if (arm_const_double_rtx (x))
        return outer == SET ? 2 : -1;
      else if ((outer == COMPARE || outer == PLUS)
               && neg_const_double_rtx_ok_for_fpa (x))
        return -1;
      return 7;

    default:
      return 99;
    }
}

/* RTX costs when optimizing for size.  */
static bool
arm_size_rtx_costs (rtx x, int code, int outer_code, int *total)
{
  enum machine_mode mode = GET_MODE (x);

  if (TARGET_THUMB)
    {
      /* XXX TBD.  For now, use the standard costs.  */
      *total = thumb_rtx_costs (x, code, outer_code);
      return true;
    }

  switch (code)
    {
    case MEM:
      /* A memory access costs 1 insn if the mode is small, or the address is
         a single register, otherwise it costs one insn per word.  */
      if (REG_P (XEXP (x, 0)))
        *total = COSTS_N_INSNS (1);
      else
        *total = COSTS_N_INSNS (ARM_NUM_REGS (mode));
      return true;

    case DIV:
    case MOD:
    case UDIV:
    case UMOD:
      /* Needs a libcall, so it costs about this.  */
      *total = COSTS_N_INSNS (2);
      return false;

    case ROTATE:
      if (mode == SImode && GET_CODE (XEXP (x, 1)) == REG)
        {
          *total = COSTS_N_INSNS (2) + rtx_cost (XEXP (x, 0), code);
          return true;
        }
      /* Fall through */
    case ROTATERT:
    case ASHIFT:
    case LSHIFTRT:
    case ASHIFTRT:
      if (mode == DImode && GET_CODE (XEXP (x, 1)) == CONST_INT)
        {
          *total = COSTS_N_INSNS (3) + rtx_cost (XEXP (x, 0), code);
          return true;
        }
      else if (mode == SImode)
        {
          *total = COSTS_N_INSNS (1) + rtx_cost (XEXP (x, 0), code);
          /* Slightly disparage register shifts, but not by much.  */
          if (GET_CODE (XEXP (x, 1)) != CONST_INT)
            *total += 1 + rtx_cost (XEXP (x, 1), code);
          return true;
        }

      /* Needs a libcall.  */
      *total = COSTS_N_INSNS (2);
      return false;

    case MINUS:
      if (TARGET_HARD_FLOAT && GET_MODE_CLASS (mode) == MODE_FLOAT)
        {
          *total = COSTS_N_INSNS (1);
          return false;
        }

      if (mode == SImode)
        {
          enum rtx_code subcode0 = GET_CODE (XEXP (x, 0));
          enum rtx_code subcode1 = GET_CODE (XEXP (x, 1));

          if (subcode0 == ROTATE || subcode0 == ROTATERT || subcode0 == ASHIFT
              || subcode0 == LSHIFTRT || subcode0 == ASHIFTRT
              || subcode1 == ROTATE || subcode1 == ROTATERT
              || subcode1 == ASHIFT || subcode1 == LSHIFTRT
              || subcode1 == ASHIFTRT)
            {
              /* It's just the cost of the two operands.  */
              *total = 0;
              return false;
            }

          *total = COSTS_N_INSNS (1);
          return false;
        }

      *total = COSTS_N_INSNS (ARM_NUM_REGS (mode));
      return false;

    case PLUS:
      if (TARGET_HARD_FLOAT && GET_MODE_CLASS (mode) == MODE_FLOAT)
        {
          *total = COSTS_N_INSNS (1);
          return false;
        }

      /* Fall through */
    case AND: case XOR: case IOR:
      if (mode == SImode)
        {
          enum rtx_code subcode = GET_CODE (XEXP (x, 0));

          if (subcode == ROTATE || subcode == ROTATERT || subcode == ASHIFT
              || subcode == LSHIFTRT || subcode == ASHIFTRT
              || (code == AND && subcode == NOT))
            {
              /* It's just the cost of the two operands.  */
              *total = 0;
              return false;
            }
        }

      *total = COSTS_N_INSNS (ARM_NUM_REGS (mode));
      return false;

    case MULT:
      *total = COSTS_N_INSNS (ARM_NUM_REGS (mode));
      return false;

    case NEG:
      if (TARGET_HARD_FLOAT && GET_MODE_CLASS (mode) == MODE_FLOAT)
        *total = COSTS_N_INSNS (1);
      /* Fall through */
    case NOT:
      *total = COSTS_N_INSNS (ARM_NUM_REGS (mode));

      return false;

    case IF_THEN_ELSE:
      *total = 0;
      return false;

    case COMPARE:
      if (cc_register (XEXP (x, 0), VOIDmode))
        * total = 0;
      else
        *total = COSTS_N_INSNS (1);
      return false;

    case ABS:
      if (TARGET_HARD_FLOAT && GET_MODE_CLASS (mode) == MODE_FLOAT)
        *total = COSTS_N_INSNS (1);
      else
        *total = COSTS_N_INSNS (1 + ARM_NUM_REGS (mode));
      return false;

    case SIGN_EXTEND:
      *total = 0;
      if (GET_MODE_SIZE (GET_MODE (XEXP (x, 0))) < 4)
        {
          if (!(arm_arch4 && MEM_P (XEXP (x, 0))))
            *total += COSTS_N_INSNS (arm_arch6 ? 1 : 2);
        }
      if (mode == DImode)
        *total += COSTS_N_INSNS (1);
      return false;

    case ZERO_EXTEND:
      *total = 0;
      if (!(arm_arch4 && MEM_P (XEXP (x, 0))))
        {
          switch (GET_MODE (XEXP (x, 0)))
            {
            case QImode:
              *total += COSTS_N_INSNS (1);
              break;

            case HImode:
              *total += COSTS_N_INSNS (arm_arch6 ? 1 : 2);

            case SImode:
              break;

            default:
              *total += COSTS_N_INSNS (2);
            }
        }

      if (mode == DImode)
        *total += COSTS_N_INSNS (1);

      return false;

    case CONST_INT:
      if (const_ok_for_arm (INTVAL (x)))
        *total = COSTS_N_INSNS (outer_code == SET ? 1 : 0);
      else if (const_ok_for_arm (~INTVAL (x)))
        *total = COSTS_N_INSNS (outer_code == AND ? 0 : 1);
      else if (const_ok_for_arm (-INTVAL (x)))
        {
          if (outer_code == COMPARE || outer_code == PLUS
              || outer_code == MINUS)
            *total = 0;
          else
            *total = COSTS_N_INSNS (1);
        }
      else
        *total = COSTS_N_INSNS (2);
      return true;

    case CONST:
    case LABEL_REF:
    case SYMBOL_REF:
      *total = COSTS_N_INSNS (2);
      return true;

    case CONST_DOUBLE:
      *total = COSTS_N_INSNS (4);
      return true;

    default:
      if (mode != VOIDmode)
        *total = COSTS_N_INSNS (ARM_NUM_REGS (mode));
      else
        *total = COSTS_N_INSNS (4); /* How knows?  */
      return false;
    }
}

/* RTX costs for cores with a slow MUL implementation.  */

static bool
arm_slowmul_rtx_costs (rtx x, int code, int outer_code, int *total)
{
  enum machine_mode mode = GET_MODE (x);

  if (TARGET_THUMB)
    {
      *total = thumb_rtx_costs (x, code, outer_code);
      return true;
    }

  switch (code)
    {
    case MULT:
      if (GET_MODE_CLASS (mode) == MODE_FLOAT
          || mode == DImode)
        {
          *total = 30;
          return true;
        }

      if (GET_CODE (XEXP (x, 1)) == CONST_INT)
        {
          unsigned HOST_WIDE_INT i = (INTVAL (XEXP (x, 1))
                                      & (unsigned HOST_WIDE_INT) 0xffffffff);
          int cost, const_ok = const_ok_for_arm (i);
          int j, booth_unit_size;

          /* Tune as appropriate.  */
          cost = const_ok ? 4 : 8;
          booth_unit_size = 2;
          for (j = 0; i && j < 32; j += booth_unit_size)
            {
              i >>= booth_unit_size;
              cost += 2;
            }

          *total = cost;
          return true;
        }

      *total = 30 + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : 4)
                  + (REG_OR_SUBREG_REG (XEXP (x, 1)) ? 0 : 4);
      return true;

    default:
      *total = arm_rtx_costs_1 (x, code, outer_code);
      return true;
    }
}


/* RTX cost for cores with a fast multiply unit (M variants).  */

static bool
arm_fastmul_rtx_costs (rtx x, int code, int outer_code, int *total)
{
  enum machine_mode mode = GET_MODE (x);

  if (TARGET_THUMB)
    {
      *total = thumb_rtx_costs (x, code, outer_code);
      return true;
    }

  switch (code)
    {
    case MULT:
      /* There is no point basing this on the tuning, since it is always the
         fast variant if it exists at all.  */
      if (mode == DImode
          && (GET_CODE (XEXP (x, 0)) == GET_CODE (XEXP (x, 1)))
          && (GET_CODE (XEXP (x, 0)) == ZERO_EXTEND
              || GET_CODE (XEXP (x, 0)) == SIGN_EXTEND))
        {
          *total = 8;
          return true;
        }


      if (GET_MODE_CLASS (mode) == MODE_FLOAT
          || mode == DImode)
        {
          *total = 30;
          return true;
        }

      if (GET_CODE (XEXP (x, 1)) == CONST_INT)
        {
          unsigned HOST_WIDE_INT i = (INTVAL (XEXP (x, 1))
                                      & (unsigned HOST_WIDE_INT) 0xffffffff);
          int cost, const_ok = const_ok_for_arm (i);
          int j, booth_unit_size;

          /* Tune as appropriate.  */
          cost = const_ok ? 4 : 8;
          booth_unit_size = 8;
          for (j = 0; i && j < 32; j += booth_unit_size)
            {
              i >>= booth_unit_size;
              cost += 2;
            }

          *total = cost;
          return true;
        }

      *total = 8 + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : 4)
                 + (REG_OR_SUBREG_REG (XEXP (x, 1)) ? 0 : 4);
      return true;

    default:
      *total = arm_rtx_costs_1 (x, code, outer_code);
      return true;
    }
}


/* RTX cost for XScale CPUs.  */

static bool
arm_xscale_rtx_costs (rtx x, int code, int outer_code, int *total)
{
  enum machine_mode mode = GET_MODE (x);

  if (TARGET_THUMB)
    {
      *total = thumb_rtx_costs (x, code, outer_code);
      return true;
    }

  switch (code)
    {
    case MULT:
      /* There is no point basing this on the tuning, since it is always the
         fast variant if it exists at all.  */
      if (mode == DImode
          && (GET_CODE (XEXP (x, 0)) == GET_CODE (XEXP (x, 1)))
          && (GET_CODE (XEXP (x, 0)) == ZERO_EXTEND
              || GET_CODE (XEXP (x, 0)) == SIGN_EXTEND))
        {
          *total = 8;
          return true;
        }


      if (GET_MODE_CLASS (mode) == MODE_FLOAT
          || mode == DImode)
        {
          *total = 30;
          return true;
        }

      if (GET_CODE (XEXP (x, 1)) == CONST_INT)
        {
          unsigned HOST_WIDE_INT i = (INTVAL (XEXP (x, 1))
                                      & (unsigned HOST_WIDE_INT) 0xffffffff);
          int cost, const_ok = const_ok_for_arm (i);
          unsigned HOST_WIDE_INT masked_const;

          /* The cost will be related to two insns.
             First a load of the constant (MOV or LDR), then a multiply.  */
          cost = 2;
          if (! const_ok)
            cost += 1;      /* LDR is probably more expensive because
                               of longer result latency.  */
          masked_const = i & 0xffff8000;
          if (masked_const != 0 && masked_const != 0xffff8000)
            {
              masked_const = i & 0xf8000000;
              if (masked_const == 0 || masked_const == 0xf8000000)
                cost += 1;
              else
                cost += 2;
            }
          *total = cost;
          return true;
        }

      *total = 8 + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : 4)
                 + (REG_OR_SUBREG_REG (XEXP (x, 1)) ? 0 : 4);
      return true;

    case COMPARE:
      /* A COMPARE of a MULT is slow on XScale; the muls instruction
         will stall until the multiplication is complete.  */
      if (GET_CODE (XEXP (x, 0)) == MULT)
        *total = 4 + rtx_cost (XEXP (x, 0), code);
      else
        *total = arm_rtx_costs_1 (x, code, outer_code);
      return true;

    default:
      *total = arm_rtx_costs_1 (x, code, outer_code);
      return true;
    }
}


/* RTX costs for 9e (and later) cores.  */

static bool
arm_9e_rtx_costs (rtx x, int code, int outer_code, int *total)
{
  enum machine_mode mode = GET_MODE (x);
  int nonreg_cost;
  int cost;

  if (TARGET_THUMB)
    {
      switch (code)
        {
        case MULT:
          *total = COSTS_N_INSNS (3);
          return true;

        default:
          *total = thumb_rtx_costs (x, code, outer_code);
          return true;
        }
    }

  switch (code)
    {
    case MULT:
      /* There is no point basing this on the tuning, since it is always the
         fast variant if it exists at all.  */
      if (mode == DImode
          && (GET_CODE (XEXP (x, 0)) == GET_CODE (XEXP (x, 1)))
          && (GET_CODE (XEXP (x, 0)) == ZERO_EXTEND
              || GET_CODE (XEXP (x, 0)) == SIGN_EXTEND))
        {
          *total = 3;
          return true;
        }


      if (GET_MODE_CLASS (mode) == MODE_FLOAT)
        {
          *total = 30;
          return true;
        }
      if (mode == DImode)
        {
          cost = 7;
          nonreg_cost = 8;
        }
      else
        {
          cost = 2;
          nonreg_cost = 4;
        }


      *total = cost + (REG_OR_SUBREG_REG (XEXP (x, 0)) ? 0 : nonreg_cost)
                    + (REG_OR_SUBREG_REG (XEXP (x, 1)) ? 0 : nonreg_cost);
      return true;

    default:
      *total = arm_rtx_costs_1 (x, code, outer_code);
      return true;
    }
}
/* All address computations that can be done are free, but rtx cost returns
   the same for practically all of them.  So we weight the different types
   of address here in the order (most pref first):
   PRE/POST_INC/DEC, SHIFT or NON-INT sum, INT sum, REG, MEM or LABEL.  */
static inline int
arm_arm_address_cost (rtx x)
{
  enum rtx_code c  = GET_CODE (x);

  if (c == PRE_INC || c == PRE_DEC || c == POST_INC || c == POST_DEC)
    return 0;
  if (c == MEM || c == LABEL_REF || c == SYMBOL_REF)
    return 10;

  if (c == PLUS || c == MINUS)
    {
      if (GET_CODE (XEXP (x, 0)) == CONST_INT)
        return 2;

      if (ARITHMETIC_P (XEXP (x, 0)) || ARITHMETIC_P (XEXP (x, 1)))
        return 3;

      return 4;
    }

  return 6;
}

static inline int
arm_thumb_address_cost (rtx x)
{
  enum rtx_code c  = GET_CODE (x);

  if (c == REG)
    return 1;
  if (c == PLUS
      && GET_CODE (XEXP (x, 0)) == REG
      && GET_CODE (XEXP (x, 1)) == CONST_INT)
    return 1;

  return 2;
}

static int
arm_address_cost (rtx x)
{
  return TARGET_ARM ? arm_arm_address_cost (x) : arm_thumb_address_cost (x);
}

static int
arm_adjust_cost (rtx insn, rtx link, rtx dep, int cost)
{
  rtx i_pat, d_pat;

  /* Some true dependencies can have a higher cost depending
     on precisely how certain input operands are used.  */
  if (arm_tune_xscale
      && REG_NOTE_KIND (link) == 0
      && recog_memoized (insn) >= 0
      && recog_memoized (dep) >= 0)
    {
      int shift_opnum = get_attr_shift (insn);
      enum attr_type attr_type = get_attr_type (dep);

      /* If nonzero, SHIFT_OPNUM contains the operand number of a shifted
         operand for INSN.  If we have a shifted input operand and the
         instruction we depend on is another ALU instruction, then we may
         have to account for an additional stall.  */
      if (shift_opnum != 0
          && (attr_type == TYPE_ALU_SHIFT || attr_type == TYPE_ALU_SHIFT_REG))
        {
          rtx shifted_operand;
          int opno;

          /* Get the shifted operand.  */
          extract_insn (insn);
          shifted_operand = recog_data.operand[shift_opnum];

          /* Iterate over all the operands in DEP.  If we write an operand
             that overlaps with SHIFTED_OPERAND, then we have increase the
             cost of this dependency.  */
          extract_insn (dep);
          preprocess_constraints ();
          for (opno = 0; opno < recog_data.n_operands; opno++)
            {
              /* We can ignore strict inputs.  */
              if (recog_data.operand_type[opno] == OP_IN)
                continue;

              if (reg_overlap_mentioned_p (recog_data.operand[opno],
                                           shifted_operand))
                return 2;
            }
        }
    }

  /* XXX This is not strictly true for the FPA.  */
  if (REG_NOTE_KIND (link) == REG_DEP_ANTI
      || REG_NOTE_KIND (link) == REG_DEP_OUTPUT)
    return 0;

  /* Call insns don't incur a stall, even if they follow a load.  */
  if (REG_NOTE_KIND (link) == 0
      && GET_CODE (insn) == CALL_INSN)
    return 1;

  if ((i_pat = single_set (insn)) != NULL
      && GET_CODE (SET_SRC (i_pat)) == MEM
      && (d_pat = single_set (dep)) != NULL
      && GET_CODE (SET_DEST (d_pat)) == MEM)
    {
      rtx src_mem = XEXP (SET_SRC (i_pat), 0);
      /* This is a load after a store, there is no conflict if the load reads
         from a cached area.  Assume that loads from the stack, and from the
         constant pool are cached, and that others will miss.  This is a
         hack.  */

      if ((GET_CODE (src_mem) == SYMBOL_REF && CONSTANT_POOL_ADDRESS_P (src_mem))
          || reg_mentioned_p (stack_pointer_rtx, src_mem)
          || reg_mentioned_p (frame_pointer_rtx, src_mem)
          || reg_mentioned_p (hard_frame_pointer_rtx, src_mem))
        return 1;
    }

  return cost;
}

static int fp_consts_inited = 0;

/* Only zero is valid for VFP.  Other values are also valid for FPA.  */
static const char * const strings_fp[8] =
{
  "0",   "1",   "2",   "3",
  "4",   "5",   "0.5", "10"
};

static REAL_VALUE_TYPE values_fp[8];

static void
init_fp_table (void)
{
  int i;
  REAL_VALUE_TYPE r;

  if (TARGET_VFP)
    fp_consts_inited = 1;
  else
    fp_consts_inited = 8;

  for (i = 0; i < fp_consts_inited; i++)
    {
      r = REAL_VALUE_ATOF (strings_fp[i], DFmode);
      values_fp[i] = r;
    }
}

/* Return TRUE if rtx X is a valid immediate FP constant.  */
int
arm_const_double_rtx (rtx x)
{
  REAL_VALUE_TYPE r;
  int i;

  if (!fp_consts_inited)
    init_fp_table ();

  REAL_VALUE_FROM_CONST_DOUBLE (r, x);
  if (REAL_VALUE_MINUS_ZERO (r))
    return 0;

  for (i = 0; i < fp_consts_inited; i++)
    if (REAL_VALUES_EQUAL (r, values_fp[i]))
      return 1;

  return 0;
}

/* Return TRUE if rtx X is a valid immediate FPA constant.  */
int
neg_const_double_rtx_ok_for_fpa (rtx x)
{
  REAL_VALUE_TYPE r;
  int i;

  if (!fp_consts_inited)
    init_fp_table ();

  REAL_VALUE_FROM_CONST_DOUBLE (r, x);
  r = REAL_VALUE_NEGATE (r);
  if (REAL_VALUE_MINUS_ZERO (r))
    return 0;

  for (i = 0; i < 8; i++)
    if (REAL_VALUES_EQUAL (r, values_fp[i]))
      return 1;

  return 0;
}
\f
/* Predicates for `match_operand' and `match_operator'.  */

/* Return nonzero if OP is a valid Cirrus memory address pattern.  */
int
cirrus_memory_offset (rtx op)
{
  /* Reject eliminable registers.  */
  if (! (reload_in_progress || reload_completed)
      && (   reg_mentioned_p (frame_pointer_rtx, op)
          || reg_mentioned_p (arg_pointer_rtx, op)
          || reg_mentioned_p (virtual_incoming_args_rtx, op)
          || reg_mentioned_p (virtual_outgoing_args_rtx, op)
          || reg_mentioned_p (virtual_stack_dynamic_rtx, op)
          || reg_mentioned_p (virtual_stack_vars_rtx, op)))
    return 0;

  if (GET_CODE (op) == MEM)
    {
      rtx ind;

      ind = XEXP (op, 0);

      /* Match: (mem (reg)).  */
      if (GET_CODE (ind) == REG)
        return 1;

      /* Match:
         (mem (plus (reg)
                    (const))).  */
      if (GET_CODE (ind) == PLUS
          && GET_CODE (XEXP (ind, 0)) == REG
          && REG_MODE_OK_FOR_BASE_P (XEXP (ind, 0), VOIDmode)
          && GET_CODE (XEXP (ind, 1)) == CONST_INT)
        return 1;
    }

  return 0;
}

/* Return TRUE if OP is a valid VFP memory address pattern.
   WB if true if writeback address modes are allowed.  */

int
arm_coproc_mem_operand (rtx op, bool wb)
{
  rtx ind;

  /* Reject eliminable registers.  */
  if (! (reload_in_progress || reload_completed)
      && (   reg_mentioned_p (frame_pointer_rtx, op)
          || reg_mentioned_p (arg_pointer_rtx, op)
          || reg_mentioned_p (virtual_incoming_args_rtx, op)
          || reg_mentioned_p (virtual_outgoing_args_rtx, op)
          || reg_mentioned_p (virtual_stack_dynamic_rtx, op)
          || reg_mentioned_p (virtual_stack_vars_rtx, op)))
    return FALSE;

  /* Constants are converted into offsets from labels.  */
  if (GET_CODE (op) != MEM)
    return FALSE;

  ind = XEXP (op, 0);

  if (reload_completed
      && (GET_CODE (ind) == LABEL_REF
          || (GET_CODE (ind) == CONST
              && GET_CODE (XEXP (ind, 0)) == PLUS
              && GET_CODE (XEXP (XEXP (ind, 0), 0)) == LABEL_REF
              && GET_CODE (XEXP (XEXP (ind, 0), 1)) == CONST_INT)))
    return TRUE;

  /* Match: (mem (reg)).  */
  if (GET_CODE (ind) == REG)
    return arm_address_register_rtx_p (ind, 0);

  /* Autoincremment addressing modes.  */
  if (wb
      && (GET_CODE (ind) == PRE_INC
          || GET_CODE (ind) == POST_INC
          || GET_CODE (ind) == PRE_DEC
          || GET_CODE (ind) == POST_DEC))
    return arm_address_register_rtx_p (XEXP (ind, 0), 0);

  if (wb
      && (GET_CODE (ind) == POST_MODIFY || GET_CODE (ind) == PRE_MODIFY)
      && arm_address_register_rtx_p (XEXP (ind, 0), 0)
      && GET_CODE (XEXP (ind, 1)) == PLUS
      && rtx_equal_p (XEXP (XEXP (ind, 1), 0), XEXP (ind, 0)))
    ind = XEXP (ind, 1);

  /* Match:
     (plus (reg)
           (const)).  */
  if (GET_CODE (ind) == PLUS
      && GET_CODE (XEXP (ind, 0)) == REG
      && REG_MODE_OK_FOR_BASE_P (XEXP (ind, 0), VOIDmode)
      && GET_CODE (XEXP (ind, 1)) == CONST_INT
      && INTVAL (XEXP (ind, 1)) > -1024
      && INTVAL (XEXP (ind, 1)) <  1024
      && (INTVAL (XEXP (ind, 1)) & 3) == 0)
    return TRUE;

  return FALSE;
}

/* Return true if X is a register that will be eliminated later on.  */
int
arm_eliminable_register (rtx x)
{
  return REG_P (x) && (REGNO (x) == FRAME_POINTER_REGNUM
                       || REGNO (x) == ARG_POINTER_REGNUM
                       || (REGNO (x) >= FIRST_VIRTUAL_REGISTER
                           && REGNO (x) <= LAST_VIRTUAL_REGISTER));
}

/* Return GENERAL_REGS if a scratch register required to reload x to/from
   VFP registers.  Otherwise return NO_REGS.  */

enum reg_class
vfp_secondary_reload_class (enum machine_mode mode, rtx x)
{
  if (arm_coproc_mem_operand (x, FALSE) || s_register_operand (x, mode))
    return NO_REGS;

  return GENERAL_REGS;
}

/* Values which must be returned in the most-significant end of the return
   register.  */

static bool
arm_return_in_msb (tree valtype)
{
  return (TARGET_AAPCS_BASED
          && BYTES_BIG_ENDIAN
          && (AGGREGATE_TYPE_P (valtype)
              || TREE_CODE (valtype) == COMPLEX_TYPE));
}

/* Returns TRUE if INSN is an "LDR REG, ADDR" instruction.
   Use by the Cirrus Maverick code which has to workaround
   a hardware bug triggered by such instructions.  */
static bool
arm_memory_load_p (rtx insn)
{
  rtx body, lhs, rhs;;

  if (insn == NULL_RTX || GET_CODE (insn) != INSN)
    return false;

  body = PATTERN (insn);

  if (GET_CODE (body) != SET)
    return false;

  lhs = XEXP (body, 0);
  rhs = XEXP (body, 1);

  lhs = REG_OR_SUBREG_RTX (lhs);

  /* If the destination is not a general purpose
     register we do not have to worry.  */
  if (GET_CODE (lhs) != REG
      || REGNO_REG_CLASS (REGNO (lhs)) != GENERAL_REGS)
    return false;

  /* As well as loads from memory we also have to react
     to loads of invalid constants which will be turned
     into loads from the minipool.  */
  return (GET_CODE (rhs) == MEM
          || GET_CODE (rhs) == SYMBOL_REF
          || note_invalid_constants (insn, -1, false));
}

/* Return TRUE if INSN is a Cirrus instruction.  */
static bool
arm_cirrus_insn_p (rtx insn)
{
  enum attr_cirrus attr;

  /* get_attr aborts on USE and CLOBBER.  */
  if (!insn
      || GET_CODE (insn) != INSN
      || GET_CODE (PATTERN (insn)) == USE
      || GET_CODE (PATTERN (insn)) == CLOBBER)
    return 0;

  attr = get_attr_cirrus (insn);

  return attr != CIRRUS_NOT;
}

/* Cirrus reorg for invalid instruction combinations.  */
static void
cirrus_reorg (rtx first)
{
  enum attr_cirrus attr;
  rtx body = PATTERN (first);
  rtx t;
  int nops;

  /* Any branch must be followed by 2 non Cirrus instructions.  */
  if (GET_CODE (first) == JUMP_INSN && GET_CODE (body) != RETURN)
    {
      nops = 0;
      t = next_nonnote_insn (first);

      if (arm_cirrus_insn_p (t))
        ++ nops;

      if (arm_cirrus_insn_p (next_nonnote_insn (t)))
        ++ nops;

      while (nops --)
        emit_insn_after (gen_nop (), first);

      return;
    }

  /* (float (blah)) is in parallel with a clobber.  */
  if (GET_CODE (body) == PARALLEL && XVECLEN (body, 0) > 0)
    body = XVECEXP (body, 0, 0);

  if (GET_CODE (body) == SET)
    {
      rtx lhs = XEXP (body, 0), rhs = XEXP (body, 1);

      /* cfldrd, cfldr64, cfstrd, cfstr64 must
         be followed by a non Cirrus insn.  */
      if (get_attr_cirrus (first) == CIRRUS_DOUBLE)
        {
          if (arm_cirrus_insn_p (next_nonnote_insn (first)))
            emit_insn_after (gen_nop (), first);

          return;
        }
      else if (arm_memory_load_p (first))
        {
          unsigned int arm_regno;

          /* Any ldr/cfmvdlr, ldr/cfmvdhr, ldr/cfmvsr, ldr/cfmv64lr,
             ldr/cfmv64hr combination where the Rd field is the same
             in both instructions must be split with a non Cirrus
             insn.  Example:

             ldr r0, blah
             nop
             cfmvsr mvf0, r0.  */

          /* Get Arm register number for ldr insn.  */
          if (GET_CODE (lhs) == REG)
            arm_regno = REGNO (lhs);
          else if (GET_CODE (rhs) == REG)
            arm_regno = REGNO (rhs);
          else
            abort ();

          /* Next insn.  */
          first = next_nonnote_insn (first);

          if (! arm_cirrus_insn_p (first))
            return;

          body = PATTERN (first);

          /* (float (blah)) is in parallel with a clobber.  */
          if (GET_CODE (body) == PARALLEL && XVECLEN (body, 0))
            body = XVECEXP (body, 0, 0);

          if (GET_CODE (body) == FLOAT)
            body = XEXP (body, 0);

          if (get_attr_cirrus (first) == CIRRUS_MOVE
              && GET_CODE (XEXP (body, 1)) == REG
              && arm_regno == REGNO (XEXP (body, 1)))
            emit_insn_after (gen_nop (), first);

          return;
        }
    }

  /* get_attr aborts on USE and CLOBBER.  */
  if (!first
      || GET_CODE (first) != INSN
      || GET_CODE (PATTERN (first)) == USE
      || GET_CODE (PATTERN (first)) == CLOBBER)
    return;

  attr = get_attr_cirrus (first);

  /* Any coprocessor compare instruction (cfcmps, cfcmpd, ...)
     must be followed by a non-coprocessor instruction.  */
  if (attr == CIRRUS_COMPARE)
    {
      nops = 0;

      t = next_nonnote_insn (first);

      if (arm_cirrus_insn_p (t))
        ++ nops;

      if (arm_cirrus_insn_p (next_nonnote_insn (t)))
        ++ nops;

      while (nops --)
        emit_insn_after (gen_nop (), first);

      return;
    }
}

/* Return TRUE if X references a SYMBOL_REF.  */
int
symbol_mentioned_p (rtx x)
{
  const char * fmt;
  int i;

  if (GET_CODE (x) == SYMBOL_REF)
    return 1;

  fmt = GET_RTX_FORMAT (GET_CODE (x));

  for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
    {
      if (fmt[i] == 'E')
        {
          int j;

          for (j = XVECLEN (x, i) - 1; j >= 0; j--)
            if (symbol_mentioned_p (XVECEXP (x, i, j)))
              return 1;
        }
      else if (fmt[i] == 'e' && symbol_mentioned_p (XEXP (x, i)))
        return 1;
    }

  return 0;
}

/* Return TRUE if X references a LABEL_REF.  */
int
label_mentioned_p (rtx x)
{
  const char * fmt;
  int i;

  if (GET_CODE (x) == LABEL_REF)
    return 1;

  fmt = GET_RTX_FORMAT (GET_CODE (x));
  for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
    {
      if (fmt[i] == 'E')
        {
          int j;

          for (j = XVECLEN (x, i) - 1; j >= 0; j--)
            if (label_mentioned_p (XVECEXP (x, i, j)))
              return 1;
        }
      else if (fmt[i] == 'e' && label_mentioned_p (XEXP (x, i)))
        return 1;
    }

  return 0;
}

enum rtx_code
minmax_code (rtx x)
{
  enum rtx_code code = GET_CODE (x);

  if (code == SMAX)
    return GE;
  else if (code == SMIN)
    return LE;
  else if (code == UMIN)
    return LEU;
  else if (code == UMAX)
    return GEU;

  abort ();
}

/* Return 1 if memory locations are adjacent.  */
int
adjacent_mem_locations (rtx a, rtx b)
{
  /* We don't guarantee to preserve the order of these memory refs.  */
  if (volatile_refs_p (a) || volatile_refs_p (b))
    return 0;

  if ((GET_CODE (XEXP (a, 0)) == REG
       || (GET_CODE (XEXP (a, 0)) == PLUS
           && GET_CODE (XEXP (XEXP (a, 0), 1)) == CONST_INT))
      && (GET_CODE (XEXP (b, 0)) == REG
          || (GET_CODE (XEXP (b, 0)) == PLUS
              && GET_CODE (XEXP (XEXP (b, 0), 1)) == CONST_INT)))
    {
      HOST_WIDE_INT val0 = 0, val1 = 0;
      rtx reg0, reg1;
      int val_diff;

      if (GET_CODE (XEXP (a, 0)) == PLUS)
        {
          reg0 = XEXP (XEXP (a, 0), 0);
          val0 = INTVAL (XEXP (XEXP (a, 0), 1));
        }
      else
        reg0 = XEXP (a, 0);

      if (GET_CODE (XEXP (b, 0)) == PLUS)
        {
          reg1 = XEXP (XEXP (b, 0), 0);
          val1 = INTVAL (XEXP (XEXP (b, 0), 1));
        }
      else
        reg1 = XEXP (b, 0);

      /* Don't accept any offset that will require multiple
         instructions to handle, since this would cause the
         arith_adjacentmem pattern to output an overlong sequence.  */
      if (!const_ok_for_op (PLUS, val0) || !const_ok_for_op (PLUS, val1))
        return 0;

      /* Don't allow an eliminable register: register elimination can make
         the offset too large.  */
      if (arm_eliminable_register (reg0))
        return 0;

      val_diff = val1 - val0;

      if (arm_ld_sched)
        {
          /* If the target has load delay slots, then there's no benefit
             to using an ldm instruction unless the offset is zero and
             we are optimizing for size.  */
          return (optimize_size && (REGNO (reg0) == REGNO (reg1))
                  && (val0 == 0 || val1 == 0 || val0 == 4 || val1 == 4)
                  && (val_diff == 4 || val_diff == -4));
        }

      return ((REGNO (reg0) == REGNO (reg1))
              && (val_diff == 4 || val_diff == -4));
    }

  return 0;
}

int
load_multiple_sequence (rtx *operands, int nops, int *regs, int *base,
                        HOST_WIDE_INT *load_offset)
{
  int unsorted_regs[4];
  HOST_WIDE_INT unsorted_offsets[4];
  int order[4];
  int base_reg = -1;
  int i;

  /* Can only handle 2, 3, or 4 insns at present,
     though could be easily extended if required.  */
  if (nops < 2 || nops > 4)
    abort ();

  /* Loop over the operands and check that the memory references are
     suitable (i.e. immediate offsets from the same base register).  At
     the same time, extract the target register, and the memory
     offsets.  */
  for (i = 0; i < nops; i++)
    {
      rtx reg;
      rtx offset;

      /* Convert a subreg of a mem into the mem itself.  */
      if (GET_CODE (operands[nops + i]) == SUBREG)
        operands[nops + i] = alter_subreg (operands + (nops + i));

      if (GET_CODE (operands[nops + i]) != MEM)
        abort ();

      /* Don't reorder volatile memory references; it doesn't seem worth
         looking for the case where the order is ok anyway.  */
      if (MEM_VOLATILE_P (operands[nops + i]))
        return 0;

      offset = const0_rtx;

      if ((GET_CODE (reg = XEXP (operands[nops + i], 0)) == REG
           || (GET_CODE (reg) == SUBREG
               && GET_CODE (reg = SUBREG_REG (reg)) == REG))
          || (GET_CODE (XEXP (operands[nops + i], 0)) == PLUS
              && ((GET_CODE (reg = XEXP (XEXP (operands[nops + i], 0), 0))
                   == REG)
                  || (GET_CODE (reg) == SUBREG
                      && GET_CODE (reg = SUBREG_REG (reg)) == REG))
              && (GET_CODE (offset = XEXP (XEXP (operands[nops + i], 0), 1))
                  == CONST_INT)))
        {
          if (i == 0)
            {
              base_reg = REGNO (reg);
              unsorted_regs[0] = (GET_CODE (operands[i]) == REG
                                  ? REGNO (operands[i])
                                  : REGNO (SUBREG_REG (operands[i])));
              order[0] = 0;
            }
          else
            {
              if (base_reg != (int) REGNO (reg))
                /* Not addressed from the same base register.  */
                return 0;

              unsorted_regs[i] = (GET_CODE (operands[i]) == REG
                                  ? REGNO (operands[i])
                                  : REGNO (SUBREG_REG (operands[i])));
              if (unsorted_regs[i] < unsorted_regs[order[0]])
                order[0] = i;
            }

          /* If it isn't an integer register, or if it overwrites the
             base register but isn't the last insn in the list, then
             we can't do this.  */
          if (unsorted_regs[i] < 0 || unsorted_regs[i] > 14
              || (i != nops - 1 && unsorted_regs[i] == base_reg))
            return 0;

          unsorted_offsets[i] = INTVAL (offset);
        }
      else
        /* Not a suitable memory address.  */
        return 0;
    }

  /* All the useful information has now been extracted from the
     operands into unsorted_regs and unsorted_offsets; additionally,
     order[0] has been set to the lowest numbered register in the
     list.  Sort the registers into order, and check that the memory
     offsets are ascending and adjacent.  */

  for (i = 1; i < nops; i++)
    {
      int j;

      order[i] = order[i - 1];
      for (j = 0; j < nops; j++)
        if (unsorted_regs[j] > unsorted_regs[order[i - 1]]
            && (order[i] == order[i - 1]
                || unsorted_regs[j] < unsorted_regs[order[i]]))
          order[i] = j;

      /* Have we found a suitable register? if not, one must be used more
         than once.  */
      if (order[i] == order[i - 1])
        return 0;

      /* Is the memory address adjacent and ascending? */
      if (unsorted_offsets[order[i]] != unsorted_offsets[order[i - 1]] + 4)
        return 0;
    }

  if (base)
    {
      *base = base_reg;

      for (i = 0; i < nops; i++)
        regs[i] = unsorted_regs[order[i]];

      *load_offset = unsorted_offsets[order[0]];
    }

  if (unsorted_offsets[order[0]] == 0)
    return 1; /* ldmia */

  if (unsorted_offsets[order[0]] == 4)
    return 2; /* ldmib */

  if (unsorted_offsets[order[nops - 1]] == 0)
    return 3; /* ldmda */

  if (unsorted_offsets[order[nops - 1]] == -4)
    return 4; /* ldmdb */

  /* For ARM8,9 & StrongARM, 2 ldr instructions are faster than an ldm
     if the offset isn't small enough.  The reason 2 ldrs are faster
     is because these ARMs are able to do more than one cache access
     in a single cycle.  The ARM9 and StrongARM have Harvard caches,
     whilst the ARM8 has a double bandwidth cache.  This means that
     these cores can do both an instruction fetch and a data fetch in
     a single cycle, so the trick of calculating the address into a
     scratch register (one of the result regs) and then doing a load
     multiple actually becomes slower (and no smaller in code size).
     That is the transformation

        ldr     rd1, [rbase + offset]
        ldr     rd2, [rbase + offset + 4]

     to

        add     rd1, rbase, offset
        ldmia   rd1, {rd1, rd2}

     produces worse code -- '3 cycles + any stalls on rd2' instead of
     '2 cycles + any stalls on rd2'.  On ARMs with only one cache
     access per cycle, the first sequence could never complete in less
     than 6 cycles, whereas the ldm sequence would only take 5 and
     would make better use of sequential accesses if not hitting the
     cache.

     We cheat here and test 'arm_ld_sched' which we currently know to
     only be true for the ARM8, ARM9 and StrongARM.  If this ever
     changes, then the test below needs to be reworked.  */
  if (nops == 2 && arm_ld_sched)
    return 0;

  /* Can't do it without setting up the offset, only do this if it takes
     no more than one insn.  */
  return (const_ok_for_arm (unsorted_offsets[order[0]])
          || const_ok_for_arm (-unsorted_offsets[order[0]])) ? 5 : 0;
}

const char *
emit_ldm_seq (rtx *operands, int nops)
{
  int regs[4];
  int base_reg;
  HOST_WIDE_INT offset;
  char buf[100];
  int i;

  switch (load_multiple_sequence (operands, nops, regs, &base_reg, &offset))
    {
    case 1:
      strcpy (buf, "ldm%?ia\t");
      break;

    case 2:
      strcpy (buf, "ldm%?ib\t");
      break;

    case 3:
      strcpy (buf, "ldm%?da\t");
      break;

    case 4:
      strcpy (buf, "ldm%?db\t");
      break;

    case 5:
      if (offset >= 0)
        sprintf (buf, "add%%?\t%s%s, %s%s, #%ld", REGISTER_PREFIX,
                 reg_names[regs[0]], REGISTER_PREFIX, reg_names[base_reg],
                 (long) offset);
      else
        sprintf (buf, "sub%%?\t%s%s, %s%s, #%ld", REGISTER_PREFIX,
                 reg_names[regs[0]], REGISTER_PREFIX, reg_names[base_reg],
                 (long) -offset);
      output_asm_insn (buf, operands);
      base_reg = regs[0];
      strcpy (buf, "ldm%?ia\t");
      break;

    default:
      abort ();
    }

  sprintf (buf + strlen (buf), "%s%s, {%s%s", REGISTER_PREFIX,
           reg_names[base_reg], REGISTER_PREFIX, reg_names[regs[0]]);

  for (i = 1; i < nops; i++)
    sprintf (buf + strlen (buf), ", %s%s", REGISTER_PREFIX,
             reg_names[regs[i]]);

  strcat (buf, "}\t%@ phole ldm");

  output_asm_insn (buf, operands);
  return "";
}

int
store_multiple_sequence (rtx *operands, int nops, int *regs, int *base,
                         HOST_WIDE_INT * load_offset)
{
  int unsorted_regs[4];
  HOST_WIDE_INT unsorted_offsets[4];
  int order[4];
  int base_reg = -1;
  int i;

  /* Can only handle 2, 3, or 4 insns at present, though could be easily
     extended if required.  */
  if (nops < 2 || nops > 4)
    abort ();

  /* Loop over the operands and check that the memory references are
     suitable (i.e. immediate offsets from the same base register).  At
     the same time, extract the target register, and the memory
     offsets.  */
  for (i = 0; i < nops; i++)
    {
      rtx reg;
      rtx offset;

      /* Convert a subreg of a mem into the mem itself.  */
      if (GET_CODE (operands[nops + i]) == SUBREG)
        operands[nops + i] = alter_subreg (operands + (nops + i));

      if (GET_CODE (operands[nops + i]) != MEM)
        abort ();

      /* Don't reorder volatile memory references; it doesn't seem worth
         looking for the case where the order is ok anyway.  */
      if (MEM_VOLATILE_P (operands[nops + i]))
        return 0;

      offset = const0_rtx;

      if ((GET_CODE (reg = XEXP (operands[nops + i], 0)) == REG
           || (GET_CODE (reg) == SUBREG
               && GET_CODE (reg = SUBREG_REG (reg)) == REG))
          || (GET_CODE (XEXP (operands[nops + i], 0)) == PLUS
              && ((GET_CODE (reg = XEXP (XEXP (operands[nops + i], 0), 0))
                   == REG)
                  || (GET_CODE (reg) == SUBREG
                      && GET_CODE (reg = SUBREG_REG (reg)) == REG))
              && (GET_CODE (offset = XEXP (XEXP (operands[nops + i], 0), 1))
                  == CONST_INT)))
        {
          if (i == 0)
            {
              base_reg = REGNO (reg);
              unsorted_regs[0] = (GET_CODE (operands[i]) == REG
                                  ? REGNO (operands[i])
                                  : REGNO (SUBREG_REG (operands[i])));
              order[0] = 0;
            }
          else
            {
              if (base_reg != (int) REGNO (reg))
                /* Not addressed from the same base register.  */
                return 0;

              unsorted_regs[i] = (GET_CODE (operands[i]) == REG
                                  ? REGNO (operands[i])
                                  : REGNO (SUBREG_REG (operands[i])));
              if (unsorted_regs[i] < unsorted_regs[order[0]])
                order[0] = i;
            }

          /* If it isn't an integer register, then we can't do this.  */
          if (unsorted_regs[i] < 0 || unsorted_regs[i] > 14)
            return 0;

          unsorted_offsets[i] = INTVAL (offset);
        }
      else
        /* Not a suitable memory address.  */
        return 0;
    }

  /* All the useful information has now been extracted from the
     operands into unsorted_regs and unsorted_offsets; additionally,
     order[0] has been set to the lowest numbered register in the
     list.  Sort the registers into order, and check that the memory
     offsets are ascending and adjacent.  */

  for (i = 1; i < nops; i++)
    {
      int j;

      order[i] = order[i - 1];
      for (j = 0; j < nops; j++)
        if (unsorted_regs[j] > unsorted_regs[order[i - 1]]
            && (order[i] == order[i - 1]
                || unsorted_regs[j] < unsorted_regs[order[i]]))
          order[i] = j;

      /* Have we found a suitable register? if not, one must be used more
         than once.  */
      if (order[i] == order[i - 1])
        return 0;

      /* Is the memory address adjacent and ascending? */
      if (unsorted_offsets[order[i]] != unsorted_offsets[order[i - 1]] + 4)
        return 0;
    }

  if (base)
    {
      *base = base_reg;

      for (i = 0; i < nops; i++)
        regs[i] = unsorted_regs[order[i]];

      *load_offset = unsorted_offsets[order[0]];
    }

  if (unsorted_offsets[order[0]] == 0)
    return 1; /* stmia */

  if (unsorted_offsets[order[0]] == 4)
    return 2; /* stmib */

  if (unsorted_offsets[order[nops - 1]] == 0)
    return 3; /* stmda */

  if (unsorted_offsets[order[nops - 1]] == -4)
    return 4; /* stmdb */

  return 0;
}

const char *
emit_stm_seq (rtx *operands, int nops)
{
  int regs[4];
  int base_reg;
  HOST_WIDE_INT offset;
  char buf[100];
  int i;

  switch (store_multiple_sequence (operands, nops, regs, &base_reg, &offset))
    {
    case 1:
      strcpy (buf, "stm%?ia\t");
      break;

    case 2:
      strcpy (buf, "stm%?ib\t");
      break;

    case 3:
      strcpy (buf, "stm%?da\t");
      break;

    case 4:
      strcpy (buf, "stm%?db\t");
      break;

    default:
      abort ();
    }

  sprintf (buf + strlen (buf), "%s%s, {%s%s", REGISTER_PREFIX,
           reg_names[base_reg], REGISTER_PREFIX, reg_names[regs[0]]);

  for (i = 1; i < nops; i++)
    sprintf (buf + strlen (buf), ", %s%s", REGISTER_PREFIX,
             reg_names[regs[i]]);

  strcat (buf, "}\t%@ phole stm");

  output_asm_insn (buf, operands);
  return "";
}

\f
/* Routines for use in generating RTL.  */

rtx
arm_gen_load_multiple (int base_regno, int count, rtx from, int up,
                       int write_back, rtx basemem, HOST_WIDE_INT *offsetp)
{
  HOST_WIDE_INT offset = *offsetp;
  int i = 0, j;
  rtx result;
  int sign = up ? 1 : -1;
  rtx mem, addr;

  /* XScale has load-store double instructions, but they have stricter
     alignment requirements than load-store multiple, so we cannot
     use them.

     For XScale ldm requires 2 + NREGS cycles to complete and blocks
     the pipeline until completion.

        NREGS           CYCLES
          1               3
          2               4
          3               5
          4               6

     An ldr instruction takes 1-3 cycles, but does not block the
     pipeline.

        NREGS           CYCLES
          1              1-3
          2              2-6
          3              3-9
          4              4-12

     Best case ldr will always win.  However, the more ldr instructions
     we issue, the less likely we are to be able to schedule them well.
     Using ldr instructions also increases code size.

     As a compromise, we use ldr for counts of 1 or 2 regs, and ldm
     for counts of 3 or 4 regs.  */
  if (arm_tune_xscale && count <= 2 && ! optimize_size)
    {
      rtx seq;

      start_sequence ();

      for (i = 0; i < count; i++)
        {
          addr = plus_constant (from, i * 4 * sign);
          mem = adjust_automodify_address (basemem, SImode, addr, offset);
          emit_move_insn (gen_rtx_REG (SImode, base_regno + i), mem);
          offset += 4 * sign;
        }

      if (write_back)
        {
          emit_move_insn (from, plus_constant (from, count * 4 * sign));
          *offsetp = offset;
        }

      seq = get_insns ();
      end_sequence ();

      return seq;
    }

  result = gen_rtx_PARALLEL (VOIDmode,
                             rtvec_alloc (count + (write_back ? 1 : 0)));
  if (write_back)
    {
      XVECEXP (result, 0, 0)
        = gen_rtx_SET (GET_MODE (from), from,
                       plus_constant (from, count * 4 * sign));
      i = 1;
      count++;
    }

  for (j = 0; i < count; i++, j++)
    {
      addr = plus_constant (from, j * 4 * sign);
      mem = adjust_automodify_address_nv (basemem, SImode, addr, offset);
      XVECEXP (result, 0, i)
        = gen_rtx_SET (VOIDmode, gen_rtx_REG (SImode, base_regno + j), mem);
      offset += 4 * sign;
    }

  if (write_back)
    *offsetp = offset;

  return result;
}

rtx
arm_gen_store_multiple (int base_regno, int count, rtx to, int up,
                        int write_back, rtx basemem, HOST_WIDE_INT *offsetp)
{
  HOST_WIDE_INT offset = *offsetp;
  int i = 0, j;
  rtx result;
  int sign = up ? 1 : -1;
  rtx mem, addr;

  /* See arm_gen_load_multiple for discussion of
     the pros/cons of ldm/stm usage for XScale.  */
  if (arm_tune_xscale && count <= 2 && ! optimize_size)
    {
      rtx seq;

      start_sequence ();

      for (i = 0; i < count; i++)
        {
          addr = plus_constant (to, i * 4 * sign);
          mem = adjust_automodify_address (basemem, SImode, addr, offset);
          emit_move_insn (mem, gen_rtx_REG (SImode, base_regno + i));
          offset += 4 * sign;
        }

      if (write_back)
        {
          emit_move_insn (to, plus_constant (to, count * 4 * sign));
          *offsetp = offset;
        }

      seq = get_insns ();
      end_sequence ();

      return seq;
    }

  result = gen_rtx_PARALLEL (VOIDmode,
                             rtvec_alloc (count + (write_back ? 1 : 0)));
  if (write_back)
    {
      XVECEXP (result, 0, 0)
        = gen_rtx_SET (GET_MODE (to), to,
                       plus_constant (to, count * 4 * sign));
      i = 1;
      count++;
    }

  for (j = 0; i < count; i++, j++)
    {
      addr = plus_constant (to, j * 4 * sign);
      mem = adjust_automodify_address_nv (basemem, SImode, addr, offset);
      XVECEXP (result, 0, i)
        = gen_rtx_SET (VOIDmode, mem, gen_rtx_REG (SImode, base_regno + j));
      offset += 4 * sign;
    }

  if (write_back)
    *offsetp = offset;

  return result;
}

int
arm_gen_movmemqi (rtx *operands)
{
  HOST_WIDE_INT in_words_to_go, out_words_to_go, last_bytes;
  HOST_WIDE_INT srcoffset, dstoffset;
  int i;
  rtx src, dst, srcbase, dstbase;
  rtx part_bytes_reg = NULL;
  rtx mem;

  if (GET_CODE (operands[2]) != CONST_INT
      || GET_CODE (operands[3]) != CONST_INT
      || INTVAL (operands[2]) > 64
      || INTVAL (operands[3]) & 3)
    return 0;

  dstbase = operands[0];
  srcbase = operands[1];

  dst = copy_to_mode_reg (SImode, XEXP (dstbase, 0));
  src = copy_to_mode_reg (SImode, XEXP (srcbase, 0));

  in_words_to_go = ARM_NUM_INTS (INTVAL (operands[2]));
  out_words_to_go = INTVAL (operands[2]) / 4;
  last_bytes = INTVAL (operands[2]) & 3;
  dstoffset = srcoffset = 0;

  if (out_words_to_go != in_words_to_go && ((in_words_to_go - 1) & 3) != 0)
    part_bytes_reg = gen_rtx_REG (SImode, (in_words_to_go - 1) & 3);

  for (i = 0; in_words_to_go >= 2; i+=4)
    {
      if (in_words_to_go > 4)
        emit_insn (arm_gen_load_multiple (0, 4, src, TRUE, TRUE,
                                          srcbase, &srcoffset));
      else
        emit_insn (arm_gen_load_multiple (0, in_words_to_go, src, TRUE,
                                          FALSE, srcbase, &srcoffset));

      if (out_words_to_go)
        {
          if (out_words_to_go > 4)
            emit_insn (arm_gen_store_multiple (0, 4, dst, TRUE, TRUE,
                                               dstbase, &dstoffset));
          else if (out_words_to_go != 1)
            emit_insn (arm_gen_store_multiple (0, out_words_to_go,
                                               dst, TRUE,
                                               (last_bytes == 0
                                                ? FALSE : TRUE),
                                               dstbase, &dstoffset));
          else
            {
              mem = adjust_automodify_address (dstbase, SImode, dst, dstoffset);
              emit_move_insn (mem, gen_rtx_REG (SImode, 0));
              if (last_bytes != 0)
                {
                  emit_insn (gen_addsi3 (dst, dst, GEN_INT (4)));
                  dstoffset += 4;
                }
            }
        }

      in_words_to_go -= in_words_to_go < 4 ? in_words_to_go : 4;
      out_words_to_go -= out_words_to_go < 4 ? out_words_to_go : 4;
    }

  /* OUT_WORDS_TO_GO will be zero here if there are byte stores to do.  */
  if (out_words_to_go)
    {
      rtx sreg;

      mem = adjust_automodify_address (srcbase, SImode, src, srcoffset);
      sreg = copy_to_reg (mem);

      mem = adjust_automodify_address (dstbase, SImode, dst, dstoffset);
      emit_move_insn (mem, sreg);
      in_words_to_go--;

      if (in_words_to_go)       /* Sanity check */
        abort ();
    }

  if (in_words_to_go)
    {
      if (in_words_to_go < 0)
        abort ();

      mem = adjust_automodify_address (srcbase, SImode, src, srcoffset);
      part_bytes_reg = copy_to_mode_reg (SImode, mem);
    }

  if (last_bytes && part_bytes_reg == NULL)
    abort ();

  if (BYTES_BIG_ENDIAN && last_bytes)
    {
      rtx tmp = gen_reg_rtx (SImode);

      /* The bytes we want are in the top end of the word.  */
      emit_insn (gen_lshrsi3 (tmp, part_bytes_reg,
                              GEN_INT (8 * (4 - last_bytes))));
      part_bytes_reg = tmp;

      while (last_bytes)
        {
          mem = adjust_automodify_address (dstbase, QImode,
                                           plus_constant (dst, last_bytes - 1),
                                           dstoffset + last_bytes - 1);
          emit_move_insn (mem, gen_lowpart (QImode, part_bytes_reg));

          if (--last_bytes)
            {
              tmp = gen_reg_rtx (SImode);
              emit_insn (gen_lshrsi3 (tmp, part_bytes_reg, GEN_INT (8)));
              part_bytes_reg = tmp;
            }
        }

    }
  else
    {
      if (last_bytes > 1)
        {
          mem = adjust_automodify_address (dstbase, HImode, dst, dstoffset);
          emit_move_insn (mem, gen_lowpart (HImode, part_bytes_reg));
          last_bytes -= 2;
          if (last_bytes)
            {
              rtx tmp = gen_reg_rtx (SImode);
              emit_insn (gen_addsi3 (dst, dst, const2_rtx));
              emit_insn (gen_lshrsi3 (tmp, part_bytes_reg, GEN_INT (16)));
              part_bytes_reg = tmp;
              dstoffset += 2;
            }
        }

      if (last_bytes)
        {
          mem = adjust_automodify_address (dstbase, QImode, dst, dstoffset);
          emit_move_insn (mem, gen_lowpart (QImode, part_bytes_reg));
        }
    }

  return 1;
}

/* Generate a memory reference for a half word, such that it will be loaded
   into the top 16 bits of the word.  We can assume that the address is
   known to be alignable and of the form reg, or plus (reg, const).  */

rtx
arm_gen_rotated_half_load (rtx memref)
{
  HOST_WIDE_INT offset = 0;
  rtx base = XEXP (memref, 0);

  if (GET_CODE (base) == PLUS)
    {
      offset = INTVAL (XEXP (base, 1));
      base = XEXP (base, 0);
    }

  /* If we aren't allowed to generate unaligned addresses, then fail.  */
  if ((BYTES_BIG_ENDIAN ? 1 : 0) ^ ((offset & 2) == 0))
    return NULL;

  base = gen_rtx_MEM (SImode, plus_constant (base, offset & ~2));

  if ((BYTES_BIG_ENDIAN ? 1 : 0) ^ ((offset & 2) == 2))
    return base;

  return gen_rtx_ROTATE (SImode, base, GEN_INT (16));
}

/* Select a dominance comparison mode if possible for a test of the general
   form (OP (COND_OR (X) (Y)) (const_int 0)).  We support three forms.
   COND_OR == DOM_CC_X_AND_Y => (X && Y)
   COND_OR == DOM_CC_NX_OR_Y => ((! X) || Y)
   COND_OR == DOM_CC_X_OR_Y => (X || Y)
   In all cases OP will be either EQ or NE, but we don't need to know which
   here.  If we are unable to support a dominance comparison we return
   CC mode.  This will then fail to match for the RTL expressions that
   generate this call.  */
enum machine_mode
arm_select_dominance_cc_mode (rtx x, rtx y, HOST_WIDE_INT cond_or)
{
  enum rtx_code cond1, cond2;
  int swapped = 0;

  /* Currently we will probably get the wrong result if the individual
     comparisons are not simple.  This also ensures that it is safe to
     reverse a comparison if necessary.  */
  if ((arm_select_cc_mode (cond1 = GET_CODE (x), XEXP (x, 0), XEXP (x, 1))
       != CCmode)
      || (arm_select_cc_mode (cond2 = GET_CODE (y), XEXP (y, 0), XEXP (y, 1))
          != CCmode))
    return CCmode;

  /* The if_then_else variant of this tests the second condition if the
     first passes, but is true if the first fails.  Reverse the first
     condition to get a true "inclusive-or" expression.  */
  if (cond_or == DOM_CC_NX_OR_Y)
    cond1 = reverse_condition (cond1);

  /* If the comparisons are not equal, and one doesn't dominate the other,
     then we can't do this.  */
  if (cond1 != cond2
      && !comparison_dominates_p (cond1, cond2)
      && (swapped = 1, !comparison_dominates_p (cond2, cond1)))
    return CCmode;

  if (swapped)
    {
      enum rtx_code temp = cond1;
      cond1 = cond2;
      cond2 = temp;
    }

  switch (cond1)
    {
    case EQ:
      if (cond2 == EQ || cond_or == DOM_CC_X_AND_Y)
        return CC_DEQmode;

      switch (cond2)
        {
        case LE: return CC_DLEmode;
        case LEU: return CC_DLEUmode;
        case GE: return CC_DGEmode;
        case GEU: return CC_DGEUmode;
        default: break;
        }

      break;

    case LT:
      if (cond2 == LT || cond_or == DOM_CC_X_AND_Y)
        return CC_DLTmode;
      if (cond2 == LE)
        return CC_DLEmode;
      if (cond2 == NE)
        return CC_DNEmode;
      break;

    case GT:
      if (cond2 == GT || cond_or == DOM_CC_X_AND_Y)
        return CC_DGTmode;
      if (cond2 == GE)
        return CC_DGEmode;
      if (cond2 == NE)
        return CC_DNEmode;
      break;

    case LTU:
      if (cond2 == LTU || cond_or == DOM_CC_X_AND_Y)
        return CC_DLTUmode;
      if (cond2 == LEU)
        return CC_DLEUmode;
      if (cond2 == NE)
        return CC_DNEmode;
      break;

    case GTU:
      if (cond2 == GTU || cond_or == DOM_CC_X_AND_Y)
        return CC_DGTUmode;
      if (cond2 == GEU)
        return CC_DGEUmode;
      if (cond2 == NE)
        return CC_DNEmode;
      break;

    /* The remaining cases only occur when both comparisons are the
       same.  */
    case NE:
      return CC_DNEmode;

    case LE:
      return CC_DLEmode;

    case GE:
      return CC_DGEmode;

    case LEU:
      return CC_DLEUmode;

    case GEU:
      return CC_DGEUmode;

    default:
      break;
    }

  abort ();
}

enum machine_mode
arm_select_cc_mode (enum rtx_code op, rtx x, rtx y)
{
  /* All floating point compares return CCFP if it is an equality
     comparison, and CCFPE otherwise.  */
  if (GET_MODE_CLASS (GET_MODE (x)) == MODE_FLOAT)
    {
      switch (op)
        {
        case EQ:
        case NE:
        case UNORDERED:
        case ORDERED:
        case UNLT:
        case UNLE:
        case UNGT:
        case UNGE:
        case UNEQ:
        case LTGT:
          return CCFPmode;

        case LT:
        case LE:
        case GT:
        case GE:
          if (TARGET_HARD_FLOAT && TARGET_MAVERICK)
            return CCFPmode;
          return CCFPEmode;

        default:
          abort ();
        }
    }

  /* A compare with a shifted operand.  Because of canonicalization, the
     comparison will have to be swapped when we emit the assembler.  */
  if (GET_MODE (y) == SImode && GET_CODE (y) == REG
      && (GET_CODE (x) == ASHIFT || GET_CODE (x) == ASHIFTRT
          || GET_CODE (x) == LSHIFTRT || GET_CODE (x) == ROTATE
          || GET_CODE (x) == ROTATERT))
    return CC_SWPmode;

  /* This operation is performed swapped, but since we only rely on the Z
     flag we don't need an additional mode.  */
  if (GET_MODE (y) == SImode && REG_P (y)
      && GET_CODE (x) == NEG
      && (op == EQ || op == NE))
    return CC_Zmode;

  /* This is a special case that is used by combine to allow a
     comparison of a shifted byte load to be split into a zero-extend
     followed by a comparison of the shifted integer (only valid for
     equalities and unsigned inequalities).  */
  if (GET_MODE (x) == SImode
      && GET_CODE (x) == ASHIFT
      && GET_CODE (XEXP (x, 1)) == CONST_INT && INTVAL (XEXP (x, 1)) == 24
      && GET_CODE (XEXP (x, 0)) == SUBREG
      && GET_CODE (SUBREG_REG (XEXP (x, 0))) == MEM
      && GET_MODE (SUBREG_REG (XEXP (x, 0))) == QImode
      && (op == EQ || op == NE
          || op == GEU || op == GTU || op == LTU || op == LEU)
      && GET_CODE (y) == CONST_INT)
    return CC_Zmode;

  /* A construct for a conditional compare, if the false arm contains
     0, then both conditions must be true, otherwise either condition
     must be true.  Not all conditions are possible, so CCmode is
     returned if it can't be done.  */
  if (GET_CODE (x) == IF_THEN_ELSE
      && (XEXP (x, 2) == const0_rtx
          || XEXP (x, 2) == const1_rtx)
      && COMPARISON_P (XEXP (x, 0))
      && COMPARISON_P (XEXP (x, 1)))
    return arm_select_dominance_cc_mode (XEXP (x, 0), XEXP (x, 1),
                                         INTVAL (XEXP (x, 2)));

  /* Alternate canonicalizations of the above.  These are somewhat cleaner.  */
  if (GET_CODE (x) == AND
      && COMPARISON_P (XEXP (x, 0))
      && COMPARISON_P (XEXP (x, 1)))
    return arm_select_dominance_cc_mode (XEXP (x, 0), XEXP (x, 1),
                                         DOM_CC_X_AND_Y);

  if (GET_CODE (x) == IOR
      && COMPARISON_P (XEXP (x, 0))
      && COMPARISON_P (XEXP (x, 1)))
    return arm_select_dominance_cc_mode (XEXP (x, 0), XEXP (x, 1),
                                         DOM_CC_X_OR_Y);

  /* An operation (on Thumb) where we want to test for a single bit.
     This is done by shifting that bit up into the top bit of a
     scratch register; we can then branch on the sign bit.  */
  if (TARGET_THUMB
      && GET_MODE (x) == SImode
      && (op == EQ || op == NE)
      && (GET_CODE (x) == ZERO_EXTRACT))
    return CC_Nmode;

  /* An operation that sets the condition codes as a side-effect, the
     V flag is not set correctly, so we can only use comparisons where
     this doesn't matter.  (For LT and GE we can use "mi" and "pl"
     instead.)  */
  if (GET_MODE (x) == SImode
      && y == const0_rtx
      && (op == EQ || op == NE || op == LT || op == GE)
      && (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
          || GET_CODE (x) == AND || GET_CODE (x) == IOR
          || GET_CODE (x) == XOR || GET_CODE (x) == MULT
          || GET_CODE (x) == NOT || GET_CODE (x) == NEG
          || GET_CODE (x) == LSHIFTRT
          || GET_CODE (x) == ASHIFT || GET_CODE (x) == ASHIFTRT
          || GET_CODE (x) == ROTATERT
          || (TARGET_ARM && GET_CODE (x) == ZERO_EXTRACT)))
    return CC_NOOVmode;

  if (GET_MODE (x) == QImode && (op == EQ || op == NE))
    return CC_Zmode;

  if (GET_MODE (x) == SImode && (op == LTU || op == GEU)
      && GET_CODE (x) == PLUS
      && (rtx_equal_p (XEXP (x, 0), y) || rtx_equal_p (XEXP (x, 1), y)))
    return CC_Cmode;

  return CCmode;
}

/* X and Y are two things to compare using CODE.  Emit the compare insn and
   return the rtx for register 0 in the proper mode.  FP means this is a
   floating point compare: I don't think that it is needed on the arm.  */
rtx
arm_gen_compare_reg (enum rtx_code code, rtx x, rtx y)
{
  enum machine_mode mode = SELECT_CC_MODE (code, x, y);
  rtx cc_reg = gen_rtx_REG (mode, CC_REGNUM);

  emit_insn (gen_rtx_SET (VOIDmode, cc_reg,
                          gen_rtx_COMPARE (mode, x, y)));

  return cc_reg;
}

/* Generate a sequence of insns that will generate the correct return
   address mask depending on the physical architecture that the program
   is running on.  */
rtx
arm_gen_return_addr_mask (void)
{
  rtx reg = gen_reg_rtx (Pmode);

  emit_insn (gen_return_addr_mask (reg));
  return reg;
}

void
arm_reload_in_hi (rtx *operands)
{
  rtx ref = operands[1];
  rtx base, scratch;
  HOST_WIDE_INT offset = 0;

  if (GET_CODE (ref) == SUBREG)
    {
      offset = SUBREG_BYTE (ref);
      ref = SUBREG_REG (ref);
    }

  if (GET_CODE (ref) == REG)
    {
      /* We have a pseudo which has been spilt onto the stack; there
         are two cases here: the first where there is a simple
         stack-slot replacement and a second where the stack-slot is
         out of range, or is used as a subreg.  */
      if (reg_equiv_mem[REGNO (ref)])
        {
          ref = reg_equiv_mem[REGNO (ref)];
          base = find_replacement (&XEXP (ref, 0));
        }
      else
        /* The slot is out of range, or was dressed up in a SUBREG.  */
        base = reg_equiv_address[REGNO (ref)];
    }
  else
    base = find_replacement (&XEXP (ref, 0));

  /* Handle the case where the address is too complex to be offset by 1.  */
  if (GET_CODE (base) == MINUS
      || (GET_CODE (base) == PLUS && GET_CODE (XEXP (base, 1)) != CONST_INT))
    {
      rtx base_plus = gen_rtx_REG (SImode, REGNO (operands[2]) + 1);

      emit_insn (gen_rtx_SET (VOIDmode, base_plus, base));
      base = base_plus;
    }
  else if (GET_CODE (base) == PLUS)
    {
      /* The addend must be CONST_INT, or we would have dealt with it above.  */
      HOST_WIDE_INT hi, lo;

      offset += INTVAL (XEXP (base, 1));
      base = XEXP (base, 0);

      /* Rework the address into a legal sequence of insns.  */
      /* Valid range for lo is -4095 -> 4095 */
      lo = (offset >= 0
            ? (offset & 0xfff)
            : -((-offset) & 0xfff));

      /* Corner case, if lo is the max offset then we would be out of range
         once we have added the additional 1 below, so bump the msb into the
         pre-loading insn(s).  */
      if (lo == 4095)
        lo &= 0x7ff;

      hi = ((((offset - lo) & (HOST_WIDE_INT) 0xffffffff)
             ^ (HOST_WIDE_INT) 0x80000000)
            - (HOST_WIDE_INT) 0x80000000);

      if (hi + lo != offset)
        abort ();

      if (hi != 0)
        {
          rtx base_plus = gen_rtx_REG (SImode, REGNO (operands[2]) + 1);

          /* Get the base address; addsi3 knows how to handle constants
             that require more than one insn.  */
          emit_insn (gen_addsi3 (base_plus, base, GEN_INT (hi)));
          base = base_plus;
          offset = lo;
        }
    }

  /* Operands[2] may overlap operands[0] (though it won't overlap
     operands[1]), that's why we asked for a DImode reg -- so we can
     use the bit that does not overlap.  */
  if (REGNO (operands[2]) == REGNO (operands[0]))
    scratch = gen_rtx_REG (SImode, REGNO (operands[2]) + 1);
  else
    scratch = gen_rtx_REG (SImode, REGNO (operands[2]));

  emit_insn (gen_zero_extendqisi2 (scratch,
                                   gen_rtx_MEM (QImode,
                                                plus_constant (base,
                                                               offset))));
  emit_insn (gen_zero_extendqisi2 (gen_rtx_SUBREG (SImode, operands[0], 0),
                                   gen_rtx_MEM (QImode,
                                                plus_constant (base,
                                                               offset + 1))));
  if (!BYTES_BIG_ENDIAN)
    emit_insn (gen_rtx_SET (VOIDmode, gen_rtx_SUBREG (SImode, operands[0], 0),
                        gen_rtx_IOR (SImode,
                                     gen_rtx_ASHIFT
                                     (SImode,
                                      gen_rtx_SUBREG (SImode, operands[0], 0),
                                      GEN_INT (8)),
                                     scratch)));
  else
    emit_insn (gen_rtx_SET (VOIDmode, gen_rtx_SUBREG (SImode, operands[0], 0),
                            gen_rtx_IOR (SImode,
                                         gen_rtx_ASHIFT (SImode, scratch,
                                                         GEN_INT (8)),
                                         gen_rtx_SUBREG (SImode, operands[0],
                                                         0))));
}

/* Handle storing a half-word to memory during reload by synthesizing as two
   byte stores.  Take care not to clobber the input values until after we
   have moved them somewhere safe.  This code assumes that if the DImode
   scratch in operands[2] overlaps either the input value or output address
   in some way, then that value must die in this insn (we absolutely need
   two scratch registers for some corner cases).  */
void
arm_reload_out_hi (rtx *operands)
{
  rtx ref = operands[0];
  rtx outval = operands[1];
  rtx base, scratch;
  HOST_WIDE_INT offset = 0;

  if (GET_CODE (ref) == SUBREG)
    {
      offset = SUBREG_BYTE (ref);
      ref = SUBREG_REG (ref);
    }

  if (GET_CODE (ref) == REG)
    {
      /* We have a pseudo which has been spilt onto the stack; there
         are two cases here: the first where there is a simple
         stack-slot replacement and a second where the stack-slot is
         out of range, or is used as a subreg.  */
      if (reg_equiv_mem[REGNO (ref)])
        {
          ref = reg_equiv_mem[REGNO (ref)];
          base = find_replacement (&XEXP (ref, 0));
        }
      else
        /* The slot is out of range, or was dressed up in a SUBREG.  */
        base = reg_equiv_address[REGNO (ref)];
    }
  else
    base = find_replacement (&XEXP (ref, 0));

  scratch = gen_rtx_REG (SImode, REGNO (operands[2]));

  /* Handle the case where the address is too complex to be offset by 1.  */
  if (GET_CODE (base) == MINUS
      || (GET_CODE (base) == PLUS && GET_CODE (XEXP (base, 1)) != CONST_INT))
    {
      rtx base_plus = gen_rtx_REG (SImode, REGNO (operands[2]) + 1);

      /* Be careful not to destroy OUTVAL.  */
      if (reg_overlap_mentioned_p (base_plus, outval))
        {
          /* Updating base_plus might destroy outval, see if we can
             swap the scratch and base_plus.  */
          if (!reg_overlap_mentioned_p (scratch, outval))
            {
              rtx tmp = scratch;
              scratch = base_plus;
              base_plus = tmp;
            }
          else
            {
              rtx scratch_hi = gen_rtx_REG (HImode, REGNO (operands[2]));

              /* Be conservative and copy OUTVAL into the scratch now,
                 this should only be necessary if outval is a subreg
                 of something larger than a word.  */
              /* XXX Might this clobber base?  I can't see how it can,
                 since scratch is known to overlap with OUTVAL, and
                 must be wider than a word.  */
              emit_insn (gen_movhi (scratch_hi, outval));
              outval = scratch_hi;
            }
        }

      emit_insn (gen_rtx_SET (VOIDmode, base_plus, base));
      base = base_plus;
    }
  else if (GET_CODE (base) == PLUS)
    {
      /* The addend must be CONST_INT, or we would have dealt with it above.  */
      HOST_WIDE_INT hi, lo;

      offset += INTVAL (XEXP (base, 1));
      base = XEXP (base, 0);

      /* Rework the address into a legal sequence of insns.  */
      /* Valid range for lo is -4095 -> 4095 */
      lo = (offset >= 0
            ? (offset & 0xfff)
            : -((-offset) & 0xfff));

      /* Corner case, if lo is the max offset then we would be out of range
         once we have added the additional 1 below, so bump the msb into the
         pre-loading insn(s).  */
      if (lo == 4095)
        lo &= 0x7ff;

      hi = ((((offset - lo) & (HOST_WIDE_INT) 0xffffffff)
             ^ (HOST_WIDE_INT) 0x80000000)
            - (HOST_WIDE_INT) 0x80000000);

      if (hi + lo != offset)
        abort ();

      if (hi != 0)
        {
          rtx base_plus = gen_rtx_REG (SImode, REGNO (operands[2]) + 1);

          /* Be careful not to destroy OUTVAL.  */
          if (reg_overlap_mentioned_p (base_plus, outval))
            {
              /* Updating base_plus might destroy outval, see if we
                 can swap the scratch and base_plus.  */
              if (!reg_overlap_mentioned_p (scratch, outval))
                {
                  rtx tmp = scratch;
                  scratch = base_plus;
                  base_plus = tmp;
                }
              else
                {
                  rtx scratch_hi = gen_rtx_REG (HImode, REGNO (operands[2]));

                  /* Be conservative and copy outval into scratch now,
                     this should only be necessary if outval is a
                     subreg of something larger than a word.  */
                  /* XXX Might this clobber base?  I can't see how it
                     can, since scratch is known to overlap with
                     outval.  */
                  emit_insn (gen_movhi (scratch_hi, outval));
                  outval = scratch_hi;
                }
            }

          /* Get the base address; addsi3 knows how to handle constants
             that require more than one insn.  */
          emit_insn (gen_addsi3 (base_plus, base, GEN_INT (hi)));
          base = base_plus;
          offset = lo;
        }
    }

  if (BYTES_BIG_ENDIAN)
    {
      emit_insn (gen_movqi (gen_rtx_MEM (QImode,
                                         plus_constant (base, offset + 1)),
                            gen_lowpart (QImode, outval)));
      emit_insn (gen_lshrsi3 (scratch,
                              gen_rtx_SUBREG (SImode, outval, 0),
                              GEN_INT (8)));
      emit_insn (gen_movqi (gen_rtx_MEM (QImode, plus_constant (base, offset)),
                            gen_lowpart (QImode, scratch)));
    }
  else
    {
      emit_insn (gen_movqi (gen_rtx_MEM (QImode, plus_constant (base, offset)),
                            gen_lowpart (QImode, outval)));
      emit_insn (gen_lshrsi3 (scratch,
                              gen_rtx_SUBREG (SImode, outval, 0),
                              GEN_INT (8)));
      emit_insn (gen_movqi (gen_rtx_MEM (QImode,
                                         plus_constant (base, offset + 1)),
                            gen_lowpart (QImode, scratch)));
    }
}

/* Return true if a type must be passed in memory. For AAPCS, small aggregates
   (padded to the size of a word) should be passed in a register.  */

static bool
arm_must_pass_in_stack (enum machine_mode mode, tree type)
{
  if (TARGET_AAPCS_BASED)
    return must_pass_in_stack_var_size (mode, type);
  else
    return must_pass_in_stack_var_size_or_pad (mode, type);
}


/* For use by FUNCTION_ARG_PADDING (MODE, TYPE).
   Return true if an argument passed on the stack should be padded upwards,
   i.e. if the least-significant byte has useful data.  */

bool
arm_pad_arg_upward (enum machine_mode mode, tree type)
{
  if (!TARGET_AAPCS_BASED)
    return DEFAULT_FUNCTION_ARG_PADDING(mode, type);

  if (type && BYTES_BIG_ENDIAN && INTEGRAL_TYPE_P (type))
    return false;

  return true;
}


/* Similarly, for use by BLOCK_REG_PADDING (MODE, TYPE, FIRST).
   For non-AAPCS, return !BYTES_BIG_ENDIAN if the least significant
   byte of the register has useful data, and return the opposite if the
   most significant byte does.
   For AAPCS, small aggregates and small complex types are always padded
   upwards.  */

bool
arm_pad_reg_upward (enum machine_mode mode ATTRIBUTE_UNUSED,
                    tree type, int first ATTRIBUTE_UNUSED)
{
  if (TARGET_AAPCS_BASED
      && BYTES_BIG_ENDIAN
      && (AGGREGATE_TYPE_P (type) || TREE_CODE (type) == COMPLEX_TYPE)
      && int_size_in_bytes (type) <= 4)
    return true;

  /* Otherwise, use default padding.  */
  return !BYTES_BIG_ENDIAN;
}


\f
/* Print a symbolic form of X to the debug file, F.  */
static void
arm_print_value (FILE *f, rtx x)
{
  switch (GET_CODE (x))
    {
    case CONST_INT:
      fprintf (f, HOST_WIDE_INT_PRINT_HEX, INTVAL (x));
      return;

    case CONST_DOUBLE:
      fprintf (f, "<0x%lx,0x%lx>", (long)XWINT (x, 2), (long)XWINT (x, 3));
      return;

    case CONST_VECTOR:
      {
        int i;

        fprintf (f, "<");
        for (i = 0; i < CONST_VECTOR_NUNITS (x); i++)
          {
            fprintf (f, HOST_WIDE_INT_PRINT_HEX, INTVAL (CONST_VECTOR_ELT (x, i)));
            if (i < (CONST_VECTOR_NUNITS (x) - 1))
              fputc (',', f);
          }
        fprintf (f, ">");
      }
      return;

    case CONST_STRING:
      fprintf (f, "\"%s\"", XSTR (x, 0));
      return;

    case SYMBOL_REF:
      fprintf (f, "`%s'", XSTR (x, 0));
      return;

    case LABEL_REF:
      fprintf (f, "L%d", INSN_UID (XEXP (x, 0)));
      return;

    case CONST:
      arm_print_value (f, XEXP (x, 0));
      return;

    case PLUS:
      arm_print_value (f, XEXP (x, 0));
      fprintf (f, "+");
      arm_print_value (f, XEXP (x, 1));
      return;

    case PC:
      fprintf (f, "pc");
      return;

    default:
      fprintf (f, "????");
      return;
    }
}
\f
/* Routines for manipulation of the constant pool.  */

/* Arm instructions cannot load a large constant directly into a
   register; they have to come from a pc relative load.  The constant
   must therefore be placed in the addressable range of the pc
   relative load.  Depending on the precise pc relative load
   instruction the range is somewhere between 256 bytes and 4k.  This
   means that we often have to dump a constant inside a function, and
   generate code to branch around it.

   It is important to minimize this, since the branches will slow
   things down and make the code larger.

   Normally we can hide the table after an existing unconditional
   branch so that there is no interruption of the flow, but in the
   worst case the code looks like this:

        ldr     rn, L1
        ...
        b       L2
        align
        L1:     .long value
        L2:
        ...

        ldr     rn, L3
        ...
        b       L4
        align
        L3:     .long value
        L4:
        ...

   We fix this by performing a scan after scheduling, which notices
   which instructions need to have their operands fetched from the
   constant table and builds the table.

   The algorithm starts by building a table of all the constants that
   need fixing up and all the natural barriers in the function (places
   where a constant table can be dropped without breaking the flow).
   For each fixup we note how far the pc-relative replacement will be
   able to reach and the offset of the instruction into the function.

   Having built the table we then group the fixes together to form
   tables that are as large as possible (subject to addressing
   constraints) and emit each table of constants after the last
   barrier that is within range of all the instructions in the group.
   If a group does not contain a barrier, then we forcibly create one
   by inserting a jump instruction into the flow.  Once the table has
   been inserted, the insns are then modified to reference the
   relevant entry in the pool.

   Possible enhancements to the algorithm (not implemented) are:

   1) For some processors and object formats, there may be benefit in
   aligning the pools to the start of cache lines; this alignment
   would need to be taken into account when calculating addressability
   of a pool.  */

/* These typedefs are located at the start of this file, so that
   they can be used in the prototypes there.  This comment is to
   remind readers of that fact so that the following structures
   can be understood more easily.

     typedef struct minipool_node    Mnode;
     typedef struct minipool_fixup   Mfix;  */

struct minipool_node
{
  /* Doubly linked chain of entries.  */
  Mnode * next;
  Mnode * prev;
  /* The maximum offset into the code that this entry can be placed.  While
     pushing fixes for forward references, all entries are sorted in order
     of increasing max_address.  */
  HOST_WIDE_INT max_address;
  /* Similarly for an entry inserted for a backwards ref.  */
  HOST_WIDE_INT min_address;
  /* The number of fixes referencing this entry.  This can become zero
     if we "unpush" an entry.  In this case we ignore the entry when we
     come to emit the code.  */
  int refcount;
  /* The offset from the start of the minipool.  */
  HOST_WIDE_INT offset;
  /* The value in table.  */
  rtx value;
  /* The mode of value.  */
  enum machine_mode mode;
  /* The size of the value.  With iWMMXt enabled
     sizes > 4 also imply an alignment of 8-bytes.  */
  int fix_size;
};

struct minipool_fixup
{
  Mfix *            next;
  rtx               insn;
  HOST_WIDE_INT     address;
  rtx *             loc;
  enum machine_mode mode;
  int               fix_size;
  rtx               value;
  Mnode *           minipool;
  HOST_WIDE_INT     forwards;
  HOST_WIDE_INT     backwards;
};

/* Fixes less than a word need padding out to a word boundary.  */
#define MINIPOOL_FIX_SIZE(mode) \
  (GET_MODE_SIZE ((mode)) >= 4 ? GET_MODE_SIZE ((mode)) : 4)

static Mnode *  minipool_vector_head;
static Mnode *  minipool_vector_tail;
static rtx      minipool_vector_label;

/* The linked list of all minipool fixes required for this function.  */
Mfix *          minipool_fix_head;
Mfix *          minipool_fix_tail;
/* The fix entry for the current minipool, once it has been placed.  */
Mfix *          minipool_barrier;

/* Determines if INSN is the start of a jump table.  Returns the end
   of the TABLE or NULL_RTX.  */
static rtx
is_jump_table (rtx insn)
{
  rtx table;

  if (GET_CODE (insn) == JUMP_INSN
      && JUMP_LABEL (insn) != NULL
      && ((table = next_real_insn (JUMP_LABEL (insn)))
          == next_real_insn (insn))
      && table != NULL
      && GET_CODE (table) == JUMP_INSN
      && (GET_CODE (PATTERN (table)) == ADDR_VEC
          || GET_CODE (PATTERN (table)) == ADDR_DIFF_VEC))
    return table;

  return NULL_RTX;
}

#ifndef JUMP_TABLES_IN_TEXT_SECTION
#define JUMP_TABLES_IN_TEXT_SECTION 0
#endif

static HOST_WIDE_INT
get_jump_table_size (rtx insn)
{
  /* ADDR_VECs only take room if read-only data does into the text
     section.  */
  if (JUMP_TABLES_IN_TEXT_SECTION
#if !defined(READONLY_DATA_SECTION) && !defined(READONLY_DATA_SECTION_ASM_OP)
      || 1
#endif
      )
    {
      rtx body = PATTERN (insn);
      int elt = GET_CODE (body) == ADDR_DIFF_VEC ? 1 : 0;

      return GET_MODE_SIZE (GET_MODE (body)) * XVECLEN (body, elt);
    }

  return 0;
}

/* Move a minipool fix MP from its current location to before MAX_MP.
   If MAX_MP is NULL, then MP doesn't need moving, but the addressing
   constraints may need updating.  */
static Mnode *
move_minipool_fix_forward_ref (Mnode *mp, Mnode *max_mp,
                               HOST_WIDE_INT max_address)
{
  /* This should never be true and the code below assumes these are
     different.  */
  if (mp == max_mp)
    abort ();

  if (max_mp == NULL)
    {
      if (max_address < mp->max_address)
        mp->max_address = max_address;
    }
  else
    {
      if (max_address > max_mp->max_address - mp->fix_size)
        mp->max_address = max_mp->max_address - mp->fix_size;
      else
        mp->max_address = max_address;

      /* Unlink MP from its current position.  Since max_mp is non-null,
       mp->prev must be non-null.  */
      mp->prev->next = mp->next;
      if (mp->next != NULL)
        mp->next->prev = mp->prev;
      else
        minipool_vector_tail = mp->prev;

      /* Re-insert it before MAX_MP.  */
      mp->next = max_mp;
      mp->prev = max_mp->prev;
      max_mp->prev = mp;

      if (mp->prev != NULL)
        mp->prev->next = mp;
      else
        minipool_vector_head = mp;
    }

  /* Save the new entry.  */
  max_mp = mp;

  /* Scan over the preceding entries and adjust their addresses as
     required.  */
  while (mp->prev != NULL
         && mp->prev->max_address > mp->max_address - mp->prev->fix_size)
    {
      mp->prev->max_address = mp->max_address - mp->prev->fix_size;
      mp = mp->prev;
    }

  return max_mp;
}

/* Add a constant to the minipool for a forward reference.  Returns the
   node added or NULL if the constant will not fit in this pool.  */
static Mnode *
add_minipool_forward_ref (Mfix *fix)
{
  /* If set, max_mp is the first pool_entry that has a lower
     constraint than the one we are trying to add.  */
  Mnode *       max_mp = NULL;
  HOST_WIDE_INT max_address = fix->address + fix->forwards;
  Mnode *       mp;

  /* If this fix's address is greater than the address of the first
     entry, then we can't put the fix in this pool.  We subtract the
     size of the current fix to ensure that if the table is fully
     packed we still have enough room to insert this value by suffling
     the other fixes forwards.  */
  if (minipool_vector_head &&
      fix->address >= minipool_vector_head->max_address - fix->fix_size)
    return NULL;

  /* Scan the pool to see if a constant with the same value has
     already been added.  While we are doing this, also note the
     location where we must insert the constant if it doesn't already
     exist.  */
  for (mp = minipool_vector_head; mp != NULL; mp = mp->next)
    {
      if (GET_CODE (fix->value) == GET_CODE (mp->value)
          && fix->mode == mp->mode
          && (GET_CODE (fix->value) != CODE_LABEL
              || (CODE_LABEL_NUMBER (fix->value)
                  == CODE_LABEL_NUMBER (mp->value)))
          && rtx_equal_p (fix->value, mp->value))
        {
          /* More than one fix references this entry.  */
          mp->refcount++;
          return move_minipool_fix_forward_ref (mp, max_mp, max_address);
        }

      /* Note the insertion point if necessary.  */
      if (max_mp == NULL
          && mp->max_address > max_address)
        max_mp = mp;

      /* If we are inserting an 8-bytes aligned quantity and
         we have not already found an insertion point, then
         make sure that all such 8-byte aligned quantities are
         placed at the start of the pool.  */
      if (ARM_DOUBLEWORD_ALIGN
          && max_mp == NULL
          && fix->fix_size == 8
          && mp->fix_size != 8)
        {
          max_mp = mp;
          max_address = mp->max_address;
        }
    }

  /* The value is not currently in the minipool, so we need to create
     a new entry for it.  If MAX_MP is NULL, the entry will be put on
     the end of the list since the placement is less constrained than
     any existing entry.  Otherwise, we insert the new fix before
     MAX_MP and, if necessary, adjust the constraints on the other
     entries.  */
  mp = xmalloc (sizeof (* mp));
  mp->fix_size = fix->fix_size;
  mp->mode = fix->mode;
  mp->value = fix->value;
  mp->refcount = 1;
  /* Not yet required for a backwards ref.  */
  mp->min_address = -65536;

  if (max_mp == NULL)
    {
      mp->max_address = max_address;
      mp->next = NULL;
      mp->prev = minipool_vector_tail;

      if (mp->prev == NULL)
        {
          minipool_vector_head = mp;
          minipool_vector_label = gen_label_rtx ();
        }
      else
        mp->prev->next = mp;

      minipool_vector_tail = mp;
    }
  else
    {
      if (max_address > max_mp->max_address - mp->fix_size)
        mp->max_address = max_mp->max_address - mp->fix_size;
      else
        mp->max_address = max_address;

      mp->next = max_mp;
      mp->prev = max_mp->prev;
      max_mp->prev = mp;
      if (mp->prev != NULL)
        mp->prev->next = mp;
      else
        minipool_vector_head = mp;
    }

  /* Save the new entry.  */
  max_mp = mp;

  /* Scan over the preceding entries and adjust their addresses as
     required.  */
  while (mp->prev != NULL
         && mp->prev->max_address > mp->max_address - mp->prev->fix_size)
    {
      mp->prev->max_address = mp->max_address - mp->prev->fix_size;
      mp = mp->prev;
    }

  return max_mp;
}

static Mnode *
move_minipool_fix_backward_ref (Mnode *mp, Mnode *min_mp,
                                HOST_WIDE_INT  min_address)
{
  HOST_WIDE_INT offset;

  /* This should never be true, and the code below assumes these are
     different.  */
  if (mp == min_mp)
    abort ();

  if (min_mp == NULL)
    {
      if (min_address > mp->min_address)
        mp->min_address = min_address;
    }
  else
    {
      /* We will adjust this below if it is too loose.  */
      mp->min_address = min_address;

      /* Unlink MP from its current position.  Since min_mp is non-null,
         mp->next must be non-null.  */
      mp->next->prev = mp->prev;
      if (mp->prev != NULL)
        mp->prev->next = mp->next;
      else
        minipool_vector_head = mp->next;

      /* Reinsert it after MIN_MP.  */
      mp->prev = min_mp;
      mp->next = min_mp->next;
      min_mp->next = mp;
      if (mp->next != NULL)
        mp->next->prev = mp;
      else
        minipool_vector_tail = mp;
    }

  min_mp = mp;

  offset = 0;
  for (mp = minipool_vector_head; mp != NULL; mp = mp->next)
    {
      mp->offset = offset;
      if (mp->refcount > 0)
        offset += mp->fix_size;

      if (mp->next && mp->next->min_address < mp->min_address + mp->fix_size)
        mp->next->min_address = mp->min_address + mp->fix_size;
    }

  return min_mp;
}

/* Add a constant to the minipool for a backward reference.  Returns the
   node added or NULL if the constant will not fit in this pool.

   Note that the code for insertion for a backwards reference can be
   somewhat confusing because the calculated offsets for each fix do
   not take into account the size of the pool (which is still under
   construction.  */
static Mnode *
add_minipool_backward_ref (Mfix *fix)
{
  /* If set, min_mp is the last pool_entry that has a lower constraint
     than the one we are trying to add.  */
  Mnode *min_mp = NULL;
  /* This can be negative, since it is only a constraint.  */
  HOST_WIDE_INT  min_address = fix->address - fix->backwards;
  Mnode *mp;

  /* If we can't reach the current pool from this insn, or if we can't
     insert this entry at the end of the pool without pushing other
     fixes out of range, then we don't try.  This ensures that we
     can't fail later on.  */
  if (min_address >= minipool_barrier->address
      || (minipool_vector_tail->min_address + fix->fix_size
          >= minipool_barrier->address))
    return NULL;

  /* Scan the pool to see if a constant with the same value has
     already been added.  While we are doing this, also note the
     location where we must insert the constant if it doesn't already
     exist.  */
  for (mp = minipool_vector_tail; mp != NULL; mp = mp->prev)
    {
      if (GET_CODE (fix->value) == GET_CODE (mp->value)
          && fix->mode == mp->mode
          && (GET_CODE (fix->value) != CODE_LABEL
              || (CODE_LABEL_NUMBER (fix->value)
                  == CODE_LABEL_NUMBER (mp->value)))
          && rtx_equal_p (fix->value, mp->value)
          /* Check that there is enough slack to move this entry to the
             end of the table (this is conservative).  */
          && (mp->max_address
              > (minipool_barrier->address
                 + minipool_vector_tail->offset
                 + minipool_vector_tail->fix_size)))
        {
          mp->refcount++;
          return move_minipool_fix_backward_ref (mp, min_mp, min_address);
        }

      if (min_mp != NULL)
        mp->min_address += fix->fix_size;
      else
        {
          /* Note the insertion point if necessary.  */
          if (mp->min_address < min_address)
            {
              /* For now, we do not allow the insertion of 8-byte alignment
                 requiring nodes anywhere but at the start of the pool.  */
              if (ARM_DOUBLEWORD_ALIGN
                  && fix->fix_size == 8 && mp->fix_size != 8)
                return NULL;
              else
                min_mp = mp;
            }
          else if (mp->max_address
                   < minipool_barrier->address + mp->offset + fix->fix_size)
            {
              /* Inserting before this entry would push the fix beyond
                 its maximum address (which can happen if we have
                 re-located a forwards fix); force the new fix to come
                 after it.  */
              min_mp = mp;
              min_address = mp->min_address + fix->fix_size;
            }
          /* If we are inserting an 8-bytes aligned quantity and
             we have not already found an insertion point, then
             make sure that all such 8-byte aligned quantities are
             placed at the start of the pool.  */
          else if (ARM_DOUBLEWORD_ALIGN
                   && min_mp == NULL
                   && fix->fix_size == 8
                   && mp->fix_size < 8)
            {
              min_mp = mp;
              min_address = mp->min_address + fix->fix_size;
            }
        }
    }

  /* We need to create a new entry.  */
  mp = xmalloc (sizeof (* mp));
  mp->fix_size = fix->fix_size;
  mp->mode = fix->mode;
  mp->value = fix->value;
  mp->refcount = 1;
  mp->max_address = minipool_barrier->address + 65536;

  mp->min_address = min_address;

  if (min_mp == NULL)
    {
      mp->prev = NULL;
      mp->next = minipool_vector_head;

      if (mp->next == NULL)
        {
          minipool_vector_tail = mp;
          minipool_vector_label = gen_label_rtx ();
        }
      else
        mp->next->prev = mp;

      minipool_vector_head = mp;
    }
  else
    {
      mp->next = min_mp->next;
      mp->prev = min_mp;
      min_mp->next = mp;

      if (mp->next != NULL)
        mp->next->prev = mp;
      else
        minipool_vector_tail = mp;
    }

  /* Save the new entry.  */
  min_mp = mp;

  if (mp->prev)
    mp = mp->prev;
  else
    mp->offset = 0;

  /* Scan over the following entries and adjust their offsets.  */
  while (mp->next != NULL)
    {
      if (mp->next->min_address < mp->min_address + mp->fix_size)
        mp->next->min_address = mp->min_address + mp->fix_size;

      if (mp->refcount)
        mp->next->offset = mp->offset + mp->fix_size;
      else
        mp->next->offset = mp->offset;

      mp = mp->next;
    }

  return min_mp;
}

static void
assign_minipool_offsets (Mfix *barrier)
{
  HOST_WIDE_INT offset = 0;
  Mnode *mp;

  minipool_barrier = barrier;

  for (mp = minipool_vector_head; mp != NULL; mp = mp->next)
    {
      mp->offset = offset;

      if (mp->refcount > 0)
        offset += mp->fix_size;
    }
}

/* Output the literal table */
static void
dump_minipool (rtx scan)
{
  Mnode * mp;
  Mnode * nmp;
  int align64 = 0;

  if (ARM_DOUBLEWORD_ALIGN)
    for (mp = minipool_vector_head; mp != NULL; mp = mp->next)
      if (mp->refcount > 0 && mp->fix_size == 8)
        {
          align64 = 1;
          break;
        }

  if (dump_file)
    fprintf (dump_file,
             ";; Emitting minipool after insn %u; address %ld; align %d (bytes)\n",
             INSN_UID (scan), (unsigned long) minipool_barrier->address, align64 ? 8 : 4);

  scan = emit_label_after (gen_label_rtx (), scan);
  scan = emit_insn_after (align64 ? gen_align_8 () : gen_align_4 (), scan);
  scan = emit_label_after (minipool_vector_label, scan);

  for (mp = minipool_vector_head; mp != NULL; mp = nmp)
    {
      if (mp->refcount > 0)
        {
          if (dump_file)
            {
              fprintf (dump_file,
                       ";;  Offset %u, min %ld, max %ld ",
                       (unsigned) mp->offset, (unsigned long) mp->min_address,
                       (unsigned long) mp->max_address);
              arm_print_value (dump_file, mp->value);
              fputc ('\n', dump_file);
            }

          switch (mp->fix_size)
            {
#ifdef HAVE_consttable_1
            case 1:
              scan = emit_insn_after (gen_consttable_1 (mp->value), scan);
              break;

#endif
#ifdef HAVE_consttable_2
            case 2:
              scan = emit_insn_after (gen_consttable_2 (mp->value), scan);
              break;

#endif
#ifdef HAVE_consttable_4
            case 4:
              scan = emit_insn_after (gen_consttable_4 (mp->value), scan);
              break;

#endif
#ifdef HAVE_consttable_8
            case 8:
              scan = emit_insn_after (gen_consttable_8 (mp->value), scan);
              break;

#endif
            default:
              abort ();
              break;
            }
        }

      nmp = mp->next;
      free (mp);
    }

  minipool_vector_head = minipool_vector_tail = NULL;
  scan = emit_insn_after (gen_consttable_end (), scan);
  scan = emit_barrier_after (scan);
}

/* Return the cost of forcibly inserting a barrier after INSN.  */
static int
arm_barrier_cost (rtx insn)
{
  /* Basing the location of the pool on the loop depth is preferable,
     but at the moment, the basic block information seems to be
     corrupt by this stage of the compilation.  */
  int base_cost = 50;
  rtx next = next_nonnote_insn (insn);

  if (next != NULL && GET_CODE (next) == CODE_LABEL)
    base_cost -= 20;

  switch (GET_CODE (insn))
    {
    case CODE_LABEL:
      /* It will always be better to place the table before the label, rather
         than after it.  */
      return 50;

    case INSN:
    case CALL_INSN:
      return base_cost;

    case JUMP_INSN:
      return base_cost - 10;

    default:
      return base_cost + 10;
    }
}

/* Find the best place in the insn stream in the range
   (FIX->address,MAX_ADDRESS) to forcibly insert a minipool barrier.
   Create the barrier by inserting a jump and add a new fix entry for
   it.  */
static Mfix *
create_fix_barrier (Mfix *fix, HOST_WIDE_INT max_address)
{
  HOST_WIDE_INT count = 0;
  rtx barrier;
  rtx from = fix->insn;
  rtx selected = from;
  int selected_cost;
  HOST_WIDE_INT selected_address;
  Mfix * new_fix;
  HOST_WIDE_INT max_count = max_address - fix->address;
  rtx label = gen_label_rtx ();

  selected_cost = arm_barrier_cost (from);
  selected_address = fix->address;

  while (from && count < max_count)
    {
      rtx tmp;
      int new_cost;

      /* This code shouldn't have been called if there was a natural barrier
         within range.  */
      if (GET_CODE (from) == BARRIER)
        abort ();

      /* Count the length of this insn.  */
      count += get_attr_length (from);

      /* If there is a jump table, add its length.  */
      tmp = is_jump_table (from);
      if (tmp != NULL)
        {
          count += get_jump_table_size (tmp);

          /* Jump tables aren't in a basic block, so base the cost on
             the dispatch insn.  If we select this location, we will
             still put the pool after the table.  */
          new_cost = arm_barrier_cost (from);

          if (count < max_count && new_cost <= selected_cost)
            {
              selected = tmp;
              selected_cost = new_cost;
              selected_address = fix->address + count;
            }

          /* Continue after the dispatch table.  */
          from = NEXT_INSN (tmp);
          continue;
        }

      new_cost = arm_barrier_cost (from);

      if (count < max_count && new_cost <= selected_cost)
        {
          selected = from;
          selected_cost = new_cost;
          selected_address = fix->address + count;
        }

      from = NEXT_INSN (from);
    }

  /* Create a new JUMP_INSN that branches around a barrier.  */
  from = emit_jump_insn_after (gen_jump (label), selected);
  JUMP_LABEL (from) = label;
  barrier = emit_barrier_after (from);
  emit_label_after (label, barrier);

  /* Create a minipool barrier entry for the new barrier.  */
  new_fix = (Mfix *) obstack_alloc (&minipool_obstack, sizeof (* new_fix));
  new_fix->insn = barrier;
  new_fix->address = selected_address;
  new_fix->next = fix->next;
  fix->next = new_fix;

  return new_fix;
}

/* Record that there is a natural barrier in the insn stream at
   ADDRESS.  */
static void
push_minipool_barrier (rtx insn, HOST_WIDE_INT address)
{
  Mfix * fix = (Mfix *) obstack_alloc (&minipool_obstack, sizeof (* fix));

  fix->insn = insn;
  fix->address = address;

  fix->next = NULL;
  if (minipool_fix_head != NULL)
    minipool_fix_tail->next = fix;
  else
    minipool_fix_head = fix;

  minipool_fix_tail = fix;
}

/* Record INSN, which will need fixing up to load a value from the
   minipool.  ADDRESS is the offset of the insn since the start of the
   function; LOC is a pointer to the part of the insn which requires
   fixing; VALUE is the constant that must be loaded, which is of type
   MODE.  */
static void
push_minipool_fix (rtx insn, HOST_WIDE_INT address, rtx *loc,
                   enum machine_mode mode, rtx value)
{
  Mfix * fix = (Mfix *) obstack_alloc (&minipool_obstack, sizeof (* fix));

#ifdef AOF_ASSEMBLER
  /* PIC symbol references need to be converted into offsets into the
     based area.  */
  /* XXX This shouldn't be done here.  */
  if (flag_pic && GET_CODE (value) == SYMBOL_REF)
    value = aof_pic_entry (value);
#endif /* AOF_ASSEMBLER */

  fix->insn = insn;
  fix->address = address;
  fix->loc = loc;
  fix->mode = mode;
  fix->fix_size = MINIPOOL_FIX_SIZE (mode);
  fix->value = value;
  fix->forwards = get_attr_pool_range (insn);
  fix->backwards = get_attr_neg_pool_range (insn);
  fix->minipool = NULL;

  /* If an insn doesn't have a range defined for it, then it isn't
     expecting to be reworked by this code.  Better to abort now than
     to generate duff assembly code.  */
  if (fix->forwards == 0 && fix->backwards == 0)
    abort ();

  /* With AAPCS/iWMMXt enabled, the pool is aligned to an 8-byte boundary.
     So there might be an empty word before the start of the pool.
     Hence we reduce the forward range by 4 to allow for this
     possibility.  */
  if (ARM_DOUBLEWORD_ALIGN && fix->fix_size == 8)
    fix->forwards -= 4;

  if (dump_file)
    {
      fprintf (dump_file,
               ";; %smode fixup for i%d; addr %lu, range (%ld,%ld): ",
               GET_MODE_NAME (mode),
               INSN_UID (insn), (unsigned long) address,
               -1 * (long)fix->backwards, (long)fix->forwards);
      arm_print_value (dump_file, fix->value);
      fprintf (dump_file, "\n");
    }

  /* Add it to the chain of fixes.  */
  fix->next = NULL;

  if (minipool_fix_head != NULL)
    minipool_fix_tail->next = fix;
  else
    minipool_fix_head = fix;

  minipool_fix_tail = fix;
}

/* Return the cost of synthesizing a 64-bit constant VAL inline.
   Returns the number of insns needed, or 99 if we don't know how to
   do it.  */
int
arm_const_double_inline_cost (rtx val)
{
  rtx lowpart, highpart;
  enum machine_mode mode;
  
  mode = GET_MODE (val);

  if (mode == VOIDmode)
    mode = DImode;

  gcc_assert (GET_MODE_SIZE (mode) == 8);
  
  lowpart = gen_lowpart (SImode, val);
  highpart = gen_highpart_mode (SImode, mode, val);
  
  gcc_assert (GET_CODE (lowpart) == CONST_INT);
  gcc_assert (GET_CODE (highpart) == CONST_INT);

  return (arm_gen_constant (SET, SImode, NULL_RTX, INTVAL (lowpart),
                            NULL_RTX, NULL_RTX, 0, 0)
          + arm_gen_constant (SET, SImode, NULL_RTX, INTVAL (highpart),
                              NULL_RTX, NULL_RTX, 0, 0));
}

/* Return true if it is worthwhile to split a 64-bit constant into two
   32-bit operations.  This is the case if optimizing for size, or
   if we have load delay slots, or if one 32-bit part can be done with
   a single data operation.  */
bool
arm_const_double_by_parts (rtx val)
{
  enum machine_mode mode = GET_MODE (val);
  rtx part;

  if (optimize_size || arm_ld_sched)
    return true;

  if (mode == VOIDmode)
    mode = DImode;
  
  part = gen_highpart_mode (SImode, mode, val);
  
  gcc_assert (GET_CODE (part) == CONST_INT);
  
  if (const_ok_for_arm (INTVAL (part))
      || const_ok_for_arm (~INTVAL (part)))
    return true;
  
  part = gen_lowpart (SImode, val);
  
  gcc_assert (GET_CODE (part) == CONST_INT);
  
  if (const_ok_for_arm (INTVAL (part))
      || const_ok_for_arm (~INTVAL (part)))
    return true;
  
  return false;
}

/* Scan INSN and note any of its operands that need fixing.
   If DO_PUSHES is false we do not actually push any of the fixups
   needed.  The function returns TRUE if any fixups were needed/pushed.
   This is used by arm_memory_load_p() which needs to know about loads
   of constants that will be converted into minipool loads.  */
static bool
note_invalid_constants (rtx insn, HOST_WIDE_INT address, int do_pushes)
{
  bool result = false;
  int opno;

  extract_insn (insn);

  if (!constrain_operands (1))
    fatal_insn_not_found (insn);

  if (recog_data.n_alternatives == 0)
    return false;

  /* Fill in recog_op_alt with information about the constraints of
     this insn.  */
  preprocess_constraints ();

  for (opno = 0; opno < recog_data.n_operands; opno++)
    {
      /* Things we need to fix can only occur in inputs.  */
      if (recog_data.operand_type[opno] != OP_IN)
        continue;

      /* If this alternative is a memory reference, then any mention
         of constants in this alternative is really to fool reload
         into allowing us to accept one there.  We need to fix them up
         now so that we output the right code.  */
      if (recog_op_alt[opno][which_alternative].memory_ok)
        {
          rtx op = recog_data.operand[opno];

          if (CONSTANT_P (op))
            {
              if (do_pushes)
                push_minipool_fix (insn, address, recog_data.operand_loc[opno],
                                   recog_data.operand_mode[opno], op);
              result = true;
            }
          else if (GET_CODE (op) == MEM
                   && GET_CODE (XEXP (op, 0)) == SYMBOL_REF
                   && CONSTANT_POOL_ADDRESS_P (XEXP (op, 0)))
            {
              if (do_pushes)
                {
                  rtx cop = avoid_constant_pool_reference (op);

                  /* Casting the address of something to a mode narrower
                     than a word can cause avoid_constant_pool_reference()
                     to return the pool reference itself.  That's no good to
                     us here.  Lets just hope that we can use the
                     constant pool value directly.  */
                  if (op == cop)
                    cop = get_pool_constant (XEXP (op, 0));

                  push_minipool_fix (insn, address,
                                     recog_data.operand_loc[opno],
                                     recog_data.operand_mode[opno], cop);
                }

              result = true;
            }
        }
    }

  return result;
}

/* Gcc puts the pool in the wrong place for ARM, since we can only
   load addresses a limited distance around the pc.  We do some
   special munging to move the constant pool values to the correct
   point in the code.  */
static void
arm_reorg (void)
{
  rtx insn;
  HOST_WIDE_INT address = 0;
  Mfix * fix;

  minipool_fix_head = minipool_fix_tail = NULL;

  /* The first insn must always be a note, or the code below won't
     scan it properly.  */
  insn = get_insns ();
  if (GET_CODE (insn) != NOTE)
    abort ();

  /* Scan all the insns and record the operands that will need fixing.  */
  for (insn = next_nonnote_insn (insn); insn; insn = next_nonnote_insn (insn))
    {
      if (TARGET_CIRRUS_FIX_INVALID_INSNS
          && (arm_cirrus_insn_p (insn)
              || GET_CODE (insn) == JUMP_INSN
              || arm_memory_load_p (insn)))
        cirrus_reorg (insn);

      if (GET_CODE (insn) == BARRIER)
        push_minipool_barrier (insn, address);
      else if (INSN_P (insn))
        {
          rtx table;

          note_invalid_constants (insn, address, true);
          address += get_attr_length (insn);

          /* If the insn is a vector jump, add the size of the table
             and skip the table.  */
          if ((table = is_jump_table (insn)) != NULL)
            {
              address += get_jump_table_size (table);
              insn = table;
            }
        }
    }

  fix = minipool_fix_head;

  /* Now scan the fixups and perform the required changes.  */
  while (fix)
    {
      Mfix * ftmp;
      Mfix * fdel;
      Mfix *  last_added_fix;
      Mfix * last_barrier = NULL;
      Mfix * this_fix;

      /* Skip any further barriers before the next fix.  */
      while (fix && GET_CODE (fix->insn) == BARRIER)
        fix = fix->next;

      /* No more fixes.  */
      if (fix == NULL)
        break;

      last_added_fix = NULL;

      for (ftmp = fix; ftmp; ftmp = ftmp->next)
        {
          if (GET_CODE (ftmp->insn) == BARRIER)
            {
              if (ftmp->address >= minipool_vector_head->max_address)
                break;

              last_barrier = ftmp;
            }
          else if ((ftmp->minipool = add_minipool_forward_ref (ftmp)) == NULL)
            break;

          last_added_fix = ftmp;  /* Keep track of the last fix added.  */
        }

      /* If we found a barrier, drop back to that; any fixes that we
         could have reached but come after the barrier will now go in
         the next mini-pool.  */
      if (last_barrier != NULL)
        {
          /* Reduce the refcount for those fixes that won't go into this
             pool after all.  */
          for (fdel = last_barrier->next;
               fdel && fdel != ftmp;
               fdel = fdel->next)
            {
              fdel->minipool->refcount--;
              fdel->minipool = NULL;
            }

          ftmp = last_barrier;
        }
      else
        {
          /* ftmp is first fix that we can't fit into this pool and
             there no natural barriers that we could use.  Insert a
             new barrier in the code somewhere between the previous
             fix and this one, and arrange to jump around it.  */
          HOST_WIDE_INT max_address;

          /* The last item on the list of fixes must be a barrier, so
             we can never run off the end of the list of fixes without
             last_barrier being set.  */
          if (ftmp == NULL)
            abort ();

          max_address = minipool_vector_head->max_address;
          /* Check that there isn't another fix that is in range that
             we couldn't fit into this pool because the pool was
             already too large: we need to put the pool before such an
             instruction.  */
          if (ftmp->address < max_address)
            max_address = ftmp->address;

          last_barrier = create_fix_barrier (last_added_fix, max_address);
        }

      assign_minipool_offsets (last_barrier);

      while (ftmp)
        {
          if (GET_CODE (ftmp->insn) != BARRIER
              && ((ftmp->minipool = add_minipool_backward_ref (ftmp))
                  == NULL))
            break;

          ftmp = ftmp->next;
        }

      /* Scan over the fixes we have identified for this pool, fixing them
         up and adding the constants to the pool itself.  */
      for (this_fix = fix; this_fix && ftmp != this_fix;
           this_fix = this_fix->next)
        if (GET_CODE (this_fix->insn) != BARRIER)
          {
            rtx addr
              = plus_constant (gen_rtx_LABEL_REF (VOIDmode,
                                                  minipool_vector_label),
                               this_fix->minipool->offset);
            *this_fix->loc = gen_rtx_MEM (this_fix->mode, addr);
          }

      dump_minipool (last_barrier->insn);
      fix = ftmp;
    }

  /* From now on we must synthesize any constants that we can't handle
     directly.  This can happen if the RTL gets split during final
     instruction generation.  */
  after_arm_reorg = 1;

  /* Free the minipool memory.  */
  obstack_free (&minipool_obstack, minipool_startobj);
}
\f
/* Routines to output assembly language.  */

/* If the rtx is the correct value then return the string of the number.
   In this way we can ensure that valid double constants are generated even
   when cross compiling.  */
const char *
fp_immediate_constant (rtx x)
{
  REAL_VALUE_TYPE r;
  int i;

  if (!fp_consts_inited)
    init_fp_table ();

  REAL_VALUE_FROM_CONST_DOUBLE (r, x);
  for (i = 0; i < 8; i++)
    if (REAL_VALUES_EQUAL (r, values_fp[i]))
      return strings_fp[i];

  abort ();
}

/* As for fp_immediate_constant, but value is passed directly, not in rtx.  */
static const char *
fp_const_from_val (REAL_VALUE_TYPE *r)
{
  int i;

  if (!fp_consts_inited)
    init_fp_table ();

  for (i = 0; i < 8; i++)
    if (REAL_VALUES_EQUAL (*r, values_fp[i]))
      return strings_fp[i];

  abort ();
}

/* Output the operands of a LDM/STM instruction to STREAM.
   MASK is the ARM register set mask of which only bits 0-15 are important.
   REG is the base register, either the frame pointer or the stack pointer,
   INSTR is the possibly suffixed load or store instruction.  */

static void
print_multi_reg (FILE *stream, const char *instr, unsigned reg,
                 unsigned long mask)
{
  unsigned i;
  bool not_first = FALSE;

  fputc ('\t', stream);
  asm_fprintf (stream, instr, reg);
  fputs (", {", stream);

  for (i = 0; i <= LAST_ARM_REGNUM; i++)
    if (mask & (1 << i))
      {
        if (not_first)
          fprintf (stream, ", ");

        asm_fprintf (stream, "%r", i);
        not_first = TRUE;
      }

  fprintf (stream, "}\n");
}


/* Output a FLDMX instruction to STREAM.
   BASE if the register containing the address.
   REG and COUNT specify the register range.
   Extra registers may be added to avoid hardware bugs.  */

static void
arm_output_fldmx (FILE * stream, unsigned int base, int reg, int count)
{
  int i;

  /* Workaround ARM10 VFPr1 bug.  */
  if (count == 2 && !arm_arch6)
    {
      if (reg == 15)
        reg--;
      count++;
    }

  fputc ('\t', stream);
  asm_fprintf (stream, "fldmfdx\t%r!, {", base);

  for (i = reg; i < reg + count; i++)
    {
      if (i > reg)
        fputs (", ", stream);
      asm_fprintf (stream, "d%d", i);
    }
  fputs ("}\n", stream);

}


/* Output the assembly for a store multiple.  */

const char *
vfp_output_fstmx (rtx * operands)
{
  char pattern[100];
  int p;
  int base;
  int i;

  strcpy (pattern, "fstmfdx\t%m0!, {%P1");
  p = strlen (pattern);

  if (GET_CODE (operands[1]) != REG)
    abort ();

  base = (REGNO (operands[1]) - FIRST_VFP_REGNUM) / 2;
  for (i = 1; i < XVECLEN (operands[2], 0); i++)
    {
      p += sprintf (&pattern[p], ", d%d", base + i);
    }
  strcpy (&pattern[p], "}");

  output_asm_insn (pattern, operands);
  return "";
}


/* Emit RTL to save block of VFP register pairs to the stack.  Returns the
   number of bytes pushed.  */

static int
vfp_emit_fstmx (int base_reg, int count)
{
  rtx par;
  rtx dwarf;
  rtx tmp, reg;
  int i;

  /* Workaround ARM10 VFPr1 bug.  Data corruption can occur when exactly two
     register pairs are stored by a store multiple insn.  We avoid this
     by pushing an extra pair.  */
  if (count == 2 && !arm_arch6)
    {
      if (base_reg == LAST_VFP_REGNUM - 3)
        base_reg -= 2;
      count++;
    }

  /* ??? The frame layout is implementation defined.  We describe
     standard format 1 (equivalent to a FSTMD insn and unused pad word).
     We really need some way of representing the whole block so that the
     unwinder can figure it out at runtime.  */
  par = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (count));
  dwarf = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (count + 1));

  reg = gen_rtx_REG (DFmode, base_reg);
  base_reg += 2;

  XVECEXP (par, 0, 0)
    = gen_rtx_SET (VOIDmode,
                   gen_rtx_MEM (BLKmode,
                                gen_rtx_PRE_DEC (BLKmode, stack_pointer_rtx)),
                   gen_rtx_UNSPEC (BLKmode,
                                   gen_rtvec (1, reg),
                                   UNSPEC_PUSH_MULT));

  tmp = gen_rtx_SET (VOIDmode, stack_pointer_rtx,
                     gen_rtx_PLUS (SImode, stack_pointer_rtx,
                                   GEN_INT (-(count * 8 + 4))));
  RTX_FRAME_RELATED_P (tmp) = 1;
  XVECEXP (dwarf, 0, 0) = tmp;

  tmp = gen_rtx_SET (VOIDmode,
                     gen_rtx_MEM (DFmode, stack_pointer_rtx),
                     reg);
  RTX_FRAME_RELATED_P (tmp) = 1;
  XVECEXP (dwarf, 0, 1) = tmp;

  for (i = 1; i < count; i++)
    {
      reg = gen_rtx_REG (DFmode, base_reg);
      base_reg += 2;
      XVECEXP (par, 0, i) = gen_rtx_USE (VOIDmode, reg);

      tmp = gen_rtx_SET (VOIDmode,
                         gen_rtx_MEM (DFmode,
                                      gen_rtx_PLUS (SImode,
                                                    stack_pointer_rtx,
                                                    GEN_INT (i * 8))),
                         reg);
      RTX_FRAME_RELATED_P (tmp) = 1;
      XVECEXP (dwarf, 0, i + 1) = tmp;
    }

  par = emit_insn (par);
  REG_NOTES (par) = gen_rtx_EXPR_LIST (REG_FRAME_RELATED_EXPR, dwarf,
                                       REG_NOTES (par));
  RTX_FRAME_RELATED_P (par) = 1;

  return count * 8 + 4;
}


/* Output a 'call' insn.  */
const char *
output_call (rtx *operands)
{
  if (arm_arch5)
    abort ();           /* Patterns should call blx <reg> directly.  */

  /* Handle calls to lr using ip (which may be clobbered in subr anyway).  */
  if (REGNO (operands[0]) == LR_REGNUM)
    {
      operands[0] = gen_rtx_REG (SImode, IP_REGNUM);
      output_asm_insn ("mov%?\t%0, %|lr", operands);
    }

  output_asm_insn ("mov%?\t%|lr, %|pc", operands);

  if (TARGET_INTERWORK || arm_arch4t)
    output_asm_insn ("bx%?\t%0", operands);
  else
    output_asm_insn ("mov%?\t%|pc, %0", operands);

  return "";
}

/* Output a 'call' insn that is a reference in memory.  */
const char *
output_call_mem (rtx *operands)
{
  if (TARGET_INTERWORK && !arm_arch5)
    {
      output_asm_insn ("ldr%?\t%|ip, %0", operands);
      output_asm_insn ("mov%?\t%|lr, %|pc", operands);
      output_asm_insn ("bx%?\t%|ip", operands);
    }
  else if (regno_use_in (LR_REGNUM, operands[0]))
    {
      /* LR is used in the memory address.  We load the address in the
         first instruction.  It's safe to use IP as the target of the
         load since the call will kill it anyway.  */
      output_asm_insn ("ldr%?\t%|ip, %0", operands);
      if (arm_arch5)
        output_asm_insn ("blx%?\t%|ip", operands);
      else
        {
          output_asm_insn ("mov%?\t%|lr, %|pc", operands);
          if (arm_arch4t)
            output_asm_insn ("bx%?\t%|ip", operands);
          else
            output_asm_insn ("mov%?\t%|pc, %|ip", operands);
        }
    }
  else
    {
      output_asm_insn ("mov%?\t%|lr, %|pc", operands);
      output_asm_insn ("ldr%?\t%|pc, %0", operands);
    }

  return "";
}


/* Output a move from arm registers to an fpa registers.
   OPERANDS[0] is an fpa register.
   OPERANDS[1] is the first registers of an arm register pair.  */
const char *
output_mov_long_double_fpa_from_arm (rtx *operands)
{
  int arm_reg0 = REGNO (operands[1]);
  rtx ops[3];

  if (arm_reg0 == IP_REGNUM)
    abort ();

  ops[0] = gen_rtx_REG (SImode, arm_reg0);
  ops[1] = gen_rtx_REG (SImode, 1 + arm_reg0);
  ops[2] = gen_rtx_REG (SImode, 2 + arm_reg0);

  output_asm_insn ("stm%?fd\t%|sp!, {%0, %1, %2}", ops);
  output_asm_insn ("ldf%?e\t%0, [%|sp], #12", operands);

  return "";
}

/* Output a move from an fpa register to arm registers.
   OPERANDS[0] is the first registers of an arm register pair.
   OPERANDS[1] is an fpa register.  */
const char *
output_mov_long_double_arm_from_fpa (rtx *operands)
{
  int arm_reg0 = REGNO (operands[0]);
  rtx ops[3];

  if (arm_reg0 == IP_REGNUM)
    abort ();

  ops[0] = gen_rtx_REG (SImode, arm_reg0);
  ops[1] = gen_rtx_REG (SImode, 1 + arm_reg0);
  ops[2] = gen_rtx_REG (SImode, 2 + arm_reg0);

  output_asm_insn ("stf%?e\t%1, [%|sp, #-12]!", operands);
  output_asm_insn ("ldm%?fd\t%|sp!, {%0, %1, %2}", ops);
  return "";
}

/* Output a move from arm registers to arm registers of a long double
   OPERANDS[0] is the destination.
   OPERANDS[1] is the source.  */
const char *
output_mov_long_double_arm_from_arm (rtx *operands)
{
  /* We have to be careful here because the two might overlap.  */
  int dest_start = REGNO (operands[0]);
  int src_start = REGNO (operands[1]);
  rtx ops[2];
  int i;

  if (dest_start < src_start)
    {
      for (i = 0; i < 3; i++)
        {
          ops[0] = gen_rtx_REG (SImode, dest_start + i);
          ops[1] = gen_rtx_REG (SImode, src_start + i);
          output_asm_insn ("mov%?\t%0, %1", ops);
        }
    }
  else
    {
      for (i = 2; i >= 0; i--)
        {
          ops[0] = gen_rtx_REG (SImode, dest_start + i);
          ops[1] = gen_rtx_REG (SImode, src_start + i);
          output_asm_insn ("mov%?\t%0, %1", ops);
        }
    }

  return "";
}


/* Output a move from arm registers to an fpa registers.
   OPERANDS[0] is an fpa register.
   OPERANDS[1] is the first registers of an arm register pair.  */
const char *
output_mov_double_fpa_from_arm (rtx *operands)
{
  int arm_reg0 = REGNO (operands[1]);
  rtx ops[2];

  if (arm_reg0 == IP_REGNUM)
    abort ();

  ops[0] = gen_rtx_REG (SImode, arm_reg0);
  ops[1] = gen_rtx_REG (SImode, 1 + arm_reg0);
  output_asm_insn ("stm%?fd\t%|sp!, {%0, %1}", ops);
  output_asm_insn ("ldf%?d\t%0, [%|sp], #8", operands);
  return "";
}

/* Output a move from an fpa register to arm registers.
   OPERANDS[0] is the first registers of an arm register pair.
   OPERANDS[1] is an fpa register.  */
const char *
output_mov_double_arm_from_fpa (rtx *operands)
{
  int arm_reg0 = REGNO (operands[0]);
  rtx ops[2];

  if (arm_reg0 == IP_REGNUM)
    abort ();

  ops[0] = gen_rtx_REG (SImode, arm_reg0);
  ops[1] = gen_rtx_REG (SImode, 1 + arm_reg0);
  output_asm_insn ("stf%?d\t%1, [%|sp, #-8]!", operands);
  output_asm_insn ("ldm%?fd\t%|sp!, {%0, %1}", ops);
  return "";
}

/* Output a move between double words.
   It must be REG<-REG, REG<-CONST_DOUBLE, REG<-CONST_INT, REG<-MEM
   or MEM<-REG and all MEMs must be offsettable addresses.  */
const char *
output_move_double (rtx *operands)
{
  enum rtx_code code0 = GET_CODE (operands[0]);
  enum rtx_code code1 = GET_CODE (operands[1]);
  rtx otherops[3];

  if (code0 == REG)
    {
      int reg0 = REGNO (operands[0]);

      otherops[0] = gen_rtx_REG (SImode, 1 + reg0);

      if (code1 == MEM)
        {
          switch (GET_CODE (XEXP (operands[1], 0)))
            {
            case REG:
              output_asm_insn ("ldm%?ia\t%m1, %M0", operands);
              break;

            case PRE_INC:
              if (!TARGET_LDRD)
                abort (); /* Should never happen now.  */
              output_asm_insn ("ldr%?d\t%0, [%m1, #8]!", operands);
              break;

            case PRE_DEC:
              output_asm_insn ("ldm%?db\t%m1!, %M0", operands);
              break;

            case POST_INC:
              output_asm_insn ("ldm%?ia\t%m1!, %M0", operands);
              break;

            case POST_DEC:
              if (!TARGET_LDRD)
                abort (); /* Should never happen now.  */
              output_asm_insn ("ldr%?d\t%0, [%m1], #-8", operands);
              break;

            case PRE_MODIFY:
            case POST_MODIFY:
              otherops[0] = operands[0];
              otherops[1] = XEXP (XEXP (XEXP (operands[1], 0), 1), 0);
              otherops[2] = XEXP (XEXP (XEXP (operands[1], 0), 1), 1);

              if (GET_CODE (XEXP (operands[1], 0)) == PRE_MODIFY)
                {
                  if (reg_overlap_mentioned_p (otherops[0], otherops[2]))
                    {
                      /* Registers overlap so split out the increment.  */
                      output_asm_insn ("add%?\t%1, %1, %2", otherops);
                      output_asm_insn ("ldr%?d\t%0, [%1] @split", otherops);
                    }
                  else
                    output_asm_insn ("ldr%?d\t%0, [%1, %2]!", otherops);
                }
              else
                {
                  /* We only allow constant increments, so this is safe.  */
                  output_asm_insn ("ldr%?d\t%0, [%1], %2", otherops);
                }
              break;

            case LABEL_REF:
            case CONST:
              output_asm_insn ("adr%?\t%0, %1", operands);
              output_asm_insn ("ldm%?ia\t%0, %M0", operands);
              break;

            default:
              if (arm_add_operand (XEXP (XEXP (operands[1], 0), 1),
                                   GET_MODE (XEXP (XEXP (operands[1], 0), 1))))
                {
                  otherops[0] = operands[0];
                  otherops[1] = XEXP (XEXP (operands[1], 0), 0);
                  otherops[2] = XEXP (XEXP (operands[1], 0), 1);

                  if (GET_CODE (XEXP (operands[1], 0)) == PLUS)
                    {
                      if (GET_CODE (otherops[2]) == CONST_INT)
                        {
                          switch ((int) INTVAL (otherops[2]))
                            {
                            case -8:
                              output_asm_insn ("ldm%?db\t%1, %M0", otherops);
                              return "";
                            case -4:
                              output_asm_insn ("ldm%?da\t%1, %M0", otherops);
                              return "";
                            case 4:
                              output_asm_insn ("ldm%?ib\t%1, %M0", otherops);
                              return "";
                            }
                        }
                      if (TARGET_LDRD
                          && (GET_CODE (otherops[2]) == REG
                              || (GET_CODE (otherops[2]) == CONST_INT
                                  && INTVAL (otherops[2]) > -256
                                  && INTVAL (otherops[2]) < 256)))
                        {
                          if (reg_overlap_mentioned_p (otherops[0],
                                                       otherops[2]))
                            {
                              /* Swap base and index registers over to
                                 avoid a conflict.  */
                              otherops[1] = XEXP (XEXP (operands[1], 0), 1);
                              otherops[2] = XEXP (XEXP (operands[1], 0), 0);

                            }
                          /* If both registers conflict, it will usually
                             have been fixed by a splitter.  */
                          if (reg_overlap_mentioned_p (otherops[0],
                                                        otherops[2]))
                            {
                              output_asm_insn ("add%?\t%1, %1, %2", otherops);
                              output_asm_insn ("ldr%?d\t%0, [%1]",
                                               otherops);
                              return "";
                            }
                          else
                            {
                              output_asm_insn ("ldr%?d\t%0, [%1, %2]",
                                               otherops);
                              return "";
                            }
                        }
                      if (GET_CODE (otherops[2]) == CONST_INT)
                        {
                          if (!(const_ok_for_arm (INTVAL (otherops[2]))))
                            output_asm_insn ("sub%?\t%0, %1, #%n2", otherops);
                          else
                            output_asm_insn ("add%?\t%0, %1, %2", otherops);
                        }
                      else
                        output_asm_insn ("add%?\t%0, %1, %2", otherops);
                    }
                  else
                    output_asm_insn ("sub%?\t%0, %1, %2", otherops);

                  return "ldm%?ia\t%0, %M0";
                }
              else
                {
                  otherops[1] = adjust_address (operands[1], SImode, 4);
                  /* Take care of overlapping base/data reg.  */
                  if (reg_mentioned_p (operands[0], operands[1]))
                    {
                      output_asm_insn ("ldr%?\t%0, %1", otherops);
                      output_asm_insn ("ldr%?\t%0, %1", operands);
                    }
                  else
                    {
                      output_asm_insn ("ldr%?\t%0, %1", operands);
                      output_asm_insn ("ldr%?\t%0, %1", otherops);
                    }
                }
            }
        }
      else
        abort ();  /* Constraints should prevent this.  */
    }
  else if (code0 == MEM && code1 == REG)
    {
      if (REGNO (operands[1]) == IP_REGNUM)
        abort ();

      switch (GET_CODE (XEXP (operands[0], 0)))
        {
        case REG:
          output_asm_insn ("stm%?ia\t%m0, %M1", operands);
          break;

        case PRE_INC:
          if (!TARGET_LDRD)
            abort (); /* Should never happen now.  */
          output_asm_insn ("str%?d\t%1, [%m0, #8]!", operands);
          break;

        case PRE_DEC:
          output_asm_insn ("stm%?db\t%m0!, %M1", operands);
          break;

        case POST_INC:
          output_asm_insn ("stm%?ia\t%m0!, %M1", operands);
          break;

        case POST_DEC:
          if (!TARGET_LDRD)
            abort (); /* Should never happen now.  */
          output_asm_insn ("str%?d\t%1, [%m0], #-8", operands);
          break;

        case PRE_MODIFY:
        case POST_MODIFY:
          otherops[0] = operands[1];
          otherops[1] = XEXP (XEXP (XEXP (operands[0], 0), 1), 0);
          otherops[2] = XEXP (XEXP (XEXP (operands[0], 0), 1), 1);

          if (GET_CODE (XEXP (operands[0], 0)) == PRE_MODIFY)
            output_asm_insn ("str%?d\t%0, [%1, %2]!", otherops);
          else
            output_asm_insn ("str%?d\t%0, [%1], %2", otherops);
          break;

        case PLUS:
          otherops[2] = XEXP (XEXP (operands[0], 0), 1);
          if (GET_CODE (otherops[2]) == CONST_INT)
            {
              switch ((int) INTVAL (XEXP (XEXP (operands[0], 0), 1)))
                {
                case -8:
                  output_asm_insn ("stm%?db\t%m0, %M1", operands);
                  return "";

                case -4:
                  output_asm_insn ("stm%?da\t%m0, %M1", operands);
                  return "";

                case 4:
                  output_asm_insn ("stm%?ib\t%m0, %M1", operands);
                  return "";
                }
            }
          if (TARGET_LDRD
              && (GET_CODE (otherops[2]) == REG
                  || (GET_CODE (otherops[2]) == CONST_INT
                      && INTVAL (otherops[2]) > -256
                      && INTVAL (otherops[2]) < 256)))
            {
              otherops[0] = operands[1];
              otherops[1] = XEXP (XEXP (operands[0], 0), 0);
              output_asm_insn ("str%?d\t%0, [%1, %2]", otherops);
              return "";
            }
          /* Fall through */

        default:
          otherops[0] = adjust_address (operands[0], SImode, 4);
          otherops[1] = gen_rtx_REG (SImode, 1 + REGNO (operands[1]));
          output_asm_insn ("str%?\t%1, %0", operands);
          output_asm_insn ("str%?\t%1, %0", otherops);
        }
    }
  else
    /* Constraints should prevent this.  */
    abort ();

  return "";
}

/* Output an ADD r, s, #n where n may be too big for one instruction.
   If adding zero to one register, output nothing.  */
const char *
output_add_immediate (rtx *operands)
{
  HOST_WIDE_INT n = INTVAL (operands[2]);

  if (n != 0 || REGNO (operands[0]) != REGNO (operands[1]))
    {
      if (n < 0)
        output_multi_immediate (operands,
                                "sub%?\t%0, %1, %2", "sub%?\t%0, %0, %2", 2,
                                -n);
      else
        output_multi_immediate (operands,
                                "add%?\t%0, %1, %2", "add%?\t%0, %0, %2", 2,
                                n);
    }

  return "";
}

/* Output a multiple immediate operation.
   OPERANDS is the vector of operands referred to in the output patterns.
   INSTR1 is the output pattern to use for the first constant.
   INSTR2 is the output pattern to use for subsequent constants.
   IMMED_OP is the index of the constant slot in OPERANDS.
   N is the constant value.  */
static const char *
output_multi_immediate (rtx *operands, const char *instr1, const char *instr2,
                        int immed_op, HOST_WIDE_INT n)
{
#if HOST_BITS_PER_WIDE_INT > 32
  n &= 0xffffffff;
#endif

  if (n == 0)
    {
      /* Quick and easy output.  */
      operands[immed_op] = const0_rtx;
      output_asm_insn (instr1, operands);
    }
  else
    {
      int i;
      const char * instr = instr1;

      /* Note that n is never zero here (which would give no output).  */
      for (i = 0; i < 32; i += 2)
        {
          if (n & (3 << i))
            {
              operands[immed_op] = GEN_INT (n & (255 << i));
              output_asm_insn (instr, operands);
              instr = instr2;
              i += 6;
            }
        }
    }

  return "";
}

/* Return the appropriate ARM instruction for the operation code.
   The returned result should not be overwritten.  OP is the rtx of the
   operation.  SHIFT_FIRST_ARG is TRUE if the first argument of the operator
   was shifted.  */
const char *
arithmetic_instr (rtx op, int shift_first_arg)
{
  switch (GET_CODE (op))
    {
    case PLUS:
      return "add";

    case MINUS:
      return shift_first_arg ? "rsb" : "sub";

    case IOR:
      return "orr";

    case XOR:
      return "eor";

    case AND:
      return "and";

    default:
      abort ();
    }
}

/* Ensure valid constant shifts and return the appropriate shift mnemonic
   for the operation code.  The returned result should not be overwritten.
   OP is the rtx code of the shift.
   On exit, *AMOUNTP will be -1 if the shift is by a register, or a constant
   shift.  */
static const char *
shift_op (rtx op, HOST_WIDE_INT *amountp)
{
  const char * mnem;
  enum rtx_code code = GET_CODE (op);

  if (GET_CODE (XEXP (op, 1)) == REG || GET_CODE (XEXP (op, 1)) == SUBREG)
    *amountp = -1;
  else if (GET_CODE (XEXP (op, 1)) == CONST_INT)
    *amountp = INTVAL (XEXP (op, 1));
  else
    abort ();

  switch (code)
    {
    case ASHIFT:
      mnem = "asl";
      break;

    case ASHIFTRT:
      mnem = "asr";
      break;

    case LSHIFTRT:
      mnem = "lsr";
      break;

    case ROTATE:
      if (*amountp == -1)
        abort ();
      *amountp = 32 - *amountp;

      /* Fall through.  */

    case ROTATERT:
      mnem = "ror";
      break;

    case MULT:
      /* We never have to worry about the amount being other than a
         power of 2, since this case can never be reloaded from a reg.  */
      if (*amountp != -1)
        *amountp = int_log2 (*amountp);
      else
        abort ();
      return "asl";

    default:
      abort ();
    }

  if (*amountp != -1)
    {
      /* This is not 100% correct, but follows from the desire to merge
         multiplication by a power of 2 with the recognizer for a
         shift.  >=32 is not a valid shift for "asl", so we must try and
         output a shift that produces the correct arithmetical result.
         Using lsr #32 is identical except for the fact that the carry bit
         is not set correctly if we set the flags; but we never use the
         carry bit from such an operation, so we can ignore that.  */
      if (code == ROTATERT)
        /* Rotate is just modulo 32.  */
        *amountp &= 31;
      else if (*amountp != (*amountp & 31))
        {
          if (code == ASHIFT)
            mnem = "lsr";
          *amountp = 32;
        }

      /* Shifts of 0 are no-ops.  */
      if (*amountp == 0)
        return NULL;
    }

  return mnem;
}

/* Obtain the shift from the POWER of two.  */

static HOST_WIDE_INT
int_log2 (HOST_WIDE_INT power)
{
  HOST_WIDE_INT shift = 0;

  while ((((HOST_WIDE_INT) 1 << shift) & power) == 0)
    {
      if (shift > 31)
        abort ();
      shift++;
    }

  return shift;
}

/* Output a .ascii pseudo-op, keeping track of lengths.  This is
   because /bin/as is horribly restrictive.  The judgement about
   whether or not each character is 'printable' (and can be output as
   is) or not (and must be printed with an octal escape) must be made
   with reference to the *host* character set -- the situation is
   similar to that discussed in the comments above pp_c_char in
   c-pretty-print.c.  */

#define MAX_ASCII_LEN 51

void
output_ascii_pseudo_op (FILE *stream, const unsigned char *p, int len)
{
  int i;
  int len_so_far = 0;

  fputs ("\t.ascii\t\"", stream);

  for (i = 0; i < len; i++)
    {
      int c = p[i];

      if (len_so_far >= MAX_ASCII_LEN)
        {
          fputs ("\"\n\t.ascii\t\"", stream);
          len_so_far = 0;
        }

      if (ISPRINT (c))
        {
          if (c == '\\' || c == '\"')
            {
              putc ('\\', stream);
              len_so_far++;
            }
          putc (c, stream);
          len_so_far++;
        }
      else
        {
          fprintf (stream, "\\%03o", c);
          len_so_far += 4;
        }
    }

  fputs ("\"\n", stream);
}
\f
/* Compute the register save mask for registers 0 through 12
   inclusive.  This code is used by arm_compute_save_reg_mask.  */

static unsigned long
arm_compute_save_reg0_reg12_mask (void)
{
  unsigned long func_type = arm_current_func_type ();
  unsigned long save_reg_mask = 0;
  unsigned int reg;

  if (IS_INTERRUPT (func_type))
    {
      unsigned int max_reg;
      /* Interrupt functions must not corrupt any registers,
         even call clobbered ones.  If this is a leaf function
         we can just examine the registers used by the RTL, but
         otherwise we have to assume that whatever function is
         called might clobber anything, and so we have to save
         all the call-clobbered registers as well.  */
      if (ARM_FUNC_TYPE (func_type) == ARM_FT_FIQ)
        /* FIQ handlers have registers r8 - r12 banked, so
           we only need to check r0 - r7, Normal ISRs only
           bank r14 and r15, so we must check up to r12.
           r13 is the stack pointer which is always preserved,
           so we do not need to consider it here.  */
        max_reg = 7;
      else
        max_reg = 12;

      for (reg = 0; reg <= max_reg; reg++)
        if (regs_ever_live[reg]
            || (! current_function_is_leaf && call_used_regs [reg]))
          save_reg_mask |= (1 << reg);

      /* Also save the pic base register if necessary.  */
      if (flag_pic
          && !TARGET_SINGLE_PIC_BASE
          && current_function_uses_pic_offset_table)
        save_reg_mask |= 1 << PIC_OFFSET_TABLE_REGNUM;
    }
  else
    {
      /* In the normal case we only need to save those registers
         which are call saved and which are used by this function.  */
      for (reg = 0; reg <= 10; reg++)
        if (regs_ever_live[reg] && ! call_used_regs [reg])
          save_reg_mask |= (1 << reg);

      /* Handle the frame pointer as a special case.  */
      if (! TARGET_APCS_FRAME
          && ! frame_pointer_needed
          && regs_ever_live[HARD_FRAME_POINTER_REGNUM]
          && ! call_used_regs[HARD_FRAME_POINTER_REGNUM])
        save_reg_mask |= 1 << HARD_FRAME_POINTER_REGNUM;

      /* If we aren't loading the PIC register,
         don't stack it even though it may be live.  */
      if (flag_pic
          && !TARGET_SINGLE_PIC_BASE 
          && (regs_ever_live[PIC_OFFSET_TABLE_REGNUM]
              || current_function_uses_pic_offset_table))
        save_reg_mask |= 1 << PIC_OFFSET_TABLE_REGNUM;
    }

  /* Save registers so the exception handler can modify them.  */
  if (current_function_calls_eh_return)
    {
      unsigned int i;

      for (i = 0; ; i++)
        {
          reg = EH_RETURN_DATA_REGNO (i);
          if (reg == INVALID_REGNUM)
            break;
          save_reg_mask |= 1 << reg;
        }
    }

  return save_reg_mask;
}

/* Compute a bit mask of which registers need to be
   saved on the stack for the current function.  */

static unsigned long
arm_compute_save_reg_mask (void)
{
  unsigned int save_reg_mask = 0;
  unsigned long func_type = arm_current_func_type ();

  if (IS_NAKED (func_type))
    /* This should never really happen.  */
    return 0;

  /* If we are creating a stack frame, then we must save the frame pointer,
     IP (which will hold the old stack pointer), LR and the PC.  */
  if (frame_pointer_needed)
    save_reg_mask |=
      (1 << ARM_HARD_FRAME_POINTER_REGNUM)
      | (1 << IP_REGNUM)
      | (1 << LR_REGNUM)
      | (1 << PC_REGNUM);

  /* Volatile functions do not return, so there
     is no need to save any other registers.  */
  if (IS_VOLATILE (func_type))
    return save_reg_mask;

  save_reg_mask |= arm_compute_save_reg0_reg12_mask ();

  /* Decide if we need to save the link register.
     Interrupt routines have their own banked link register,
     so they never need to save it.
     Otherwise if we do not use the link register we do not need to save
     it.  If we are pushing other registers onto the stack however, we
     can save an instruction in the epilogue by pushing the link register
     now and then popping it back into the PC.  This incurs extra memory
     accesses though, so we only do it when optimizing for size, and only
     if we know that we will not need a fancy return sequence.  */
  if (regs_ever_live [LR_REGNUM]
          || (save_reg_mask
              && optimize_size
              && ARM_FUNC_TYPE (func_type) == ARM_FT_NORMAL
              && !current_function_calls_eh_return))
    save_reg_mask |= 1 << LR_REGNUM;

  if (cfun->machine->lr_save_eliminated)
    save_reg_mask &= ~ (1 << LR_REGNUM);

  if (TARGET_REALLY_IWMMXT
      && ((bit_count (save_reg_mask)
           + ARM_NUM_INTS (current_function_pretend_args_size)) % 2) != 0)
    {
      unsigned int reg;

      /* The total number of registers that are going to be pushed
         onto the stack is odd.  We need to ensure that the stack
         is 64-bit aligned before we start to save iWMMXt registers,
         and also before we start to create locals.  (A local variable
         might be a double or long long which we will load/store using
         an iWMMXt instruction).  Therefore we need to push another
         ARM register, so that the stack will be 64-bit aligned.  We
         try to avoid using the arg registers (r0 -r3) as they might be
         used to pass values in a tail call.  */
      for (reg = 4; reg <= 12; reg++)
        if ((save_reg_mask & (1 << reg)) == 0)
          break;

      if (reg <= 12)
        save_reg_mask |= (1 << reg);
      else
        {
          cfun->machine->sibcall_blocked = 1;
          save_reg_mask |= (1 << 3);
        }
    }

  return save_reg_mask;
}


/* Compute a bit mask of which registers need to be
   saved on the stack for the current function.  */
static unsigned long
thumb_compute_save_reg_mask (void)
{
  unsigned long mask;
  unsigned reg;

  mask = 0;
  for (reg = 0; reg < 12; reg ++)
    if (regs_ever_live[reg] && !call_used_regs[reg])
      mask |= 1 << reg;

  if (flag_pic && !TARGET_SINGLE_PIC_BASE)
    mask |= (1 << PIC_OFFSET_TABLE_REGNUM);

  if (TARGET_SINGLE_PIC_BASE)
    mask &= ~(1 << arm_pic_register);

  /* See if we might need r11 for calls to _interwork_r11_call_via_rN().  */
  if (!frame_pointer_needed && CALLER_INTERWORKING_SLOT_SIZE > 0)
    mask |= 1 << ARM_HARD_FRAME_POINTER_REGNUM;

  /* LR will also be pushed if any lo regs are pushed.  */
  if (mask & 0xff || thumb_force_lr_save ())
    mask |= (1 << LR_REGNUM);

  /* Make sure we have a low work register if we need one.
     We will need one if we are going to push a high register,
     but we are not currently intending to push a low register.  */
  if ((mask & 0xff) == 0
      && ((mask & 0x0f00) || TARGET_BACKTRACE))
    {
      /* Use thumb_find_work_register to choose which register
         we will use.  If the register is live then we will
         have to push it.  Use LAST_LO_REGNUM as our fallback
         choice for the register to select.  */
      reg = thumb_find_work_register (1 << LAST_LO_REGNUM);

      if (! call_used_regs[reg])
        mask |= 1 << reg;
    }

  return mask;
}


/* Return the number of bytes required to save VFP registers.  */
static int
arm_get_vfp_saved_size (void)
{
  unsigned int regno;
  int count;
  int saved;

  saved = 0;
  /* Space for saved VFP registers.  */
  if (TARGET_HARD_FLOAT && TARGET_VFP)
    {
      count = 0;
      for (regno = FIRST_VFP_REGNUM;
           regno < LAST_VFP_REGNUM;
           regno += 2)
        {
          if ((!regs_ever_live[regno] || call_used_regs[regno])
              && (!regs_ever_live[regno + 1] || call_used_regs[regno + 1]))
            {
              if (count > 0)
                {
                  /* Workaround ARM10 VFPr1 bug.  */
                  if (count == 2 && !arm_arch6)
                    count++;
                  saved += count * 8 + 4;
                }
              count = 0;
            }
          else
            count++;
        }
      if (count > 0)
        {
          if (count == 2 && !arm_arch6)
            count++;
          saved += count * 8 + 4;
        }
    }
  return saved;
}


/* Generate a function exit sequence.  If REALLY_RETURN is false, then do
   everything bar the final return instruction.  */
const char *
output_return_instruction (rtx operand, int really_return, int reverse)
{
  char conditional[10];
  char instr[100];
  unsigned reg;
  unsigned long live_regs_mask;
  unsigned long func_type;
  arm_stack_offsets *offsets;

  func_type = arm_current_func_type ();

  if (IS_NAKED (func_type))
    return "";

  if (IS_VOLATILE (func_type) && TARGET_ABORT_NORETURN)
    {
      /* If this function was declared non-returning, and we have
         found a tail call, then we have to trust that the called
         function won't return.  */
      if (really_return)
        {
          rtx ops[2];

          /* Otherwise, trap an attempted return by aborting.  */
          ops[0] = operand;
          ops[1] = gen_rtx_SYMBOL_REF (Pmode, NEED_PLT_RELOC ? "abort(PLT)"
                                       : "abort");
          assemble_external_libcall (ops[1]);
          output_asm_insn (reverse ? "bl%D0\t%a1" : "bl%d0\t%a1", ops);
        }

      return "";
    }

  if (current_function_calls_alloca && !really_return)
    abort ();

  sprintf (conditional, "%%?%%%c0", reverse ? 'D' : 'd');

  return_used_this_function = 1;

  live_regs_mask = arm_compute_save_reg_mask ();

  if (live_regs_mask)
    {
      const char * return_reg;

      /* If we do not have any special requirements for function exit
         (e.g. interworking, or ISR) then we can load the return address
         directly into the PC.  Otherwise we must load it into LR.  */
      if (really_return
          && ! TARGET_INTERWORK)
        return_reg = reg_names[PC_REGNUM];
      else
        return_reg = reg_names[LR_REGNUM];

      if ((live_regs_mask & (1 << IP_REGNUM)) == (1 << IP_REGNUM))
        {
          /* There are three possible reasons for the IP register
             being saved.  1) a stack frame was created, in which case
             IP contains the old stack pointer, or 2) an ISR routine
             corrupted it, or 3) it was saved to align the stack on
             iWMMXt.  In case 1, restore IP into SP, otherwise just
             restore IP.  */
          if (frame_pointer_needed)
            {
              live_regs_mask &= ~ (1 << IP_REGNUM);
              live_regs_mask |=   (1 << SP_REGNUM);
            }
          else
            {
              if (! IS_INTERRUPT (func_type)
                  && ! TARGET_REALLY_IWMMXT)
                abort ();
            }
        }

      /* On some ARM architectures it is faster to use LDR rather than
         LDM to load a single register.  On other architectures, the
         cost is the same.  In 26 bit mode, or for exception handlers,
         we have to use LDM to load the PC so that the CPSR is also
         restored.  */
      for (reg = 0; reg <= LAST_ARM_REGNUM; reg++)
        if (live_regs_mask == (1U << reg))
          break;

      if (reg <= LAST_ARM_REGNUM
          && (reg != LR_REGNUM
              || ! really_return
              || ! IS_INTERRUPT (func_type)))
        {
          sprintf (instr, "ldr%s\t%%|%s, [%%|sp], #4", conditional,
                   (reg == LR_REGNUM) ? return_reg : reg_names[reg]);
        }
      else
        {
          char *p;
          int first = 1;

          /* Generate the load multiple instruction to restore the
             registers.  Note we can get here, even if
             frame_pointer_needed is true, but only if sp already
             points to the base of the saved core registers.  */
          if (live_regs_mask & (1 << SP_REGNUM))
            {
              unsigned HOST_WIDE_INT stack_adjust;

              offsets = arm_get_frame_offsets ();
              stack_adjust = offsets->outgoing_args - offsets->saved_regs;
              if (stack_adjust != 0 && stack_adjust != 4)
                abort ();

              if (stack_adjust && arm_arch5)
                sprintf (instr, "ldm%sib\t%%|sp, {", conditional);
              else
                {
                  /* If we can't use ldmib (SA110 bug),
                     then try to pop r3 instead.  */
                  if (stack_adjust)
                    live_regs_mask |= 1 << 3;
                  sprintf (instr, "ldm%sfd\t%%|sp, {", conditional);
                }
            }
          else
            sprintf (instr, "ldm%sfd\t%%|sp!, {", conditional);

          p = instr + strlen (instr);

          for (reg = 0; reg <= SP_REGNUM; reg++)
            if (live_regs_mask & (1 << reg))
              {
                int l = strlen (reg_names[reg]);

                if (first)
                  first = 0;
                else
                  {
                    memcpy (p, ", ", 2);
                    p += 2;
                  }

                memcpy (p, "%|", 2);
                memcpy (p + 2, reg_names[reg], l);
                p += l + 2;
              }

          if (live_regs_mask & (1 << LR_REGNUM))
            {
              sprintf (p, "%s%%|%s}", first ? "" : ", ", return_reg);
              /* If returning from an interrupt, restore the CPSR.  */
              if (IS_INTERRUPT (func_type))
                strcat (p, "^");
            }
          else
            strcpy (p, "}");
        }

      output_asm_insn (instr, & operand);

      /* See if we need to generate an extra instruction to
         perform the actual function return.  */
      if (really_return
          && func_type != ARM_FT_INTERWORKED
          && (live_regs_mask & (1 << LR_REGNUM)) != 0)
        {
          /* The return has already been handled
             by loading the LR into the PC.  */
          really_return = 0;
        }
    }

  if (really_return)
    {
      switch ((int) ARM_FUNC_TYPE (func_type))
        {
        case ARM_FT_ISR:
        case ARM_FT_FIQ:
          sprintf (instr, "sub%ss\t%%|pc, %%|lr, #4", conditional);
          break;

        case ARM_FT_INTERWORKED:
          sprintf (instr, "bx%s\t%%|lr", conditional);
          break;

        case ARM_FT_EXCEPTION:
          sprintf (instr, "mov%ss\t%%|pc, %%|lr", conditional);
          break;

        default:
          /* Use bx if it's available.  */
          if (arm_arch5 || arm_arch4t)
            sprintf (instr, "bx%s\t%%|lr", conditional);
          else
            sprintf (instr, "mov%s\t%%|pc, %%|lr", conditional);
          break;
        }

      output_asm_insn (instr, & operand);
    }

  return "";
}

/* Write the function name into the code section, directly preceding
   the function prologue.

   Code will be output similar to this:
     t0
         .ascii "arm_poke_function_name", 0
         .align
     t1
         .word 0xff000000 + (t1 - t0)
     arm_poke_function_name
         mov     ip, sp
         stmfd   sp!, {fp, ip, lr, pc}
         sub     fp, ip, #4

   When performing a stack backtrace, code can inspect the value
   of 'pc' stored at 'fp' + 0.  If the trace function then looks
   at location pc - 12 and the top 8 bits are set, then we know
   that there is a function name embedded immediately preceding this
   location and has length ((pc[-3]) & 0xff000000).

   We assume that pc is declared as a pointer to an unsigned long.

   It is of no benefit to output the function name if we are assembling
   a leaf function.  These function types will not contain a stack
   backtrace structure, therefore it is not possible to determine the
   function name.  */
void
arm_poke_function_name (FILE *stream, const char *name)
{
  unsigned long alignlength;
  unsigned long length;
  rtx           x;

  length      = strlen (name) + 1;
  alignlength = ROUND_UP_WORD (length);

  ASM_OUTPUT_ASCII (stream, name, length);
  ASM_OUTPUT_ALIGN (stream, 2);
  x = GEN_INT ((unsigned HOST_WIDE_INT) 0xff000000 + alignlength);
  assemble_aligned_integer (UNITS_PER_WORD, x);
}

/* Place some comments into the assembler stream
   describing the current function.  */
static void
arm_output_function_prologue (FILE *f, HOST_WIDE_INT frame_size)
{
  unsigned long func_type;

  if (!TARGET_ARM)
    {
      thumb_output_function_prologue (f, frame_size);
      return;
    }

  /* Sanity check.  */
  if (arm_ccfsm_state || arm_target_insn)
    abort ();

  func_type = arm_current_func_type ();

  switch ((int) ARM_FUNC_TYPE (func_type))
    {
    default:
    case ARM_FT_NORMAL:
      break;
    case ARM_FT_INTERWORKED:
      asm_fprintf (f, "\t%@ Function supports interworking.\n");
      break;
    case ARM_FT_ISR:
      asm_fprintf (f, "\t%@ Interrupt Service Routine.\n");
      break;
    case ARM_FT_FIQ:
      asm_fprintf (f, "\t%@ Fast Interrupt Service Routine.\n");
      break;
    case ARM_FT_EXCEPTION:
      asm_fprintf (f, "\t%@ ARM Exception Handler.\n");
      break;
    }

  if (IS_NAKED (func_type))
    asm_fprintf (f, "\t%@ Naked Function: prologue and epilogue provided by programmer.\n");

  if (IS_VOLATILE (func_type))
    asm_fprintf (f, "\t%@ Volatile: function does not return.\n");

  if (IS_NESTED (func_type))
    asm_fprintf (f, "\t%@ Nested: function declared inside another function.\n");

  asm_fprintf (f, "\t%@ args = %d, pretend = %d, frame = %wd\n",
               current_function_args_size,
               current_function_pretend_args_size, frame_size);

  asm_fprintf (f, "\t%@ frame_needed = %d, uses_anonymous_args = %d\n",
               frame_pointer_needed,
               cfun->machine->uses_anonymous_args);

  if (cfun->machine->lr_save_eliminated)
    asm_fprintf (f, "\t%@ link register save eliminated.\n");

  if (current_function_calls_eh_return)
    asm_fprintf (f, "\t@ Calls __builtin_eh_return.\n");

#ifdef AOF_ASSEMBLER
  if (flag_pic)
    asm_fprintf (f, "\tmov\t%r, %r\n", IP_REGNUM, PIC_OFFSET_TABLE_REGNUM);
#endif

  return_used_this_function = 0;
}

const char *
arm_output_epilogue (rtx sibling)
{
  int reg;
  unsigned long saved_regs_mask;
  unsigned long func_type;
  /* Floats_offset is the offset from the "virtual" frame.  In an APCS
     frame that is $fp + 4 for a non-variadic function.  */
  int floats_offset = 0;
  rtx operands[3];
  FILE * f = asm_out_file;
  unsigned int lrm_count = 0;
  int really_return = (sibling == NULL);
  int start_reg;
  arm_stack_offsets *offsets;

  /* If we have already generated the return instruction
     then it is futile to generate anything else.  */
  if (use_return_insn (FALSE, sibling) && return_used_this_function)
    return "";

  func_type = arm_current_func_type ();

  if (IS_NAKED (func_type))
    /* Naked functions don't have epilogues.  */
    return "";

  if (IS_VOLATILE (func_type) && TARGET_ABORT_NORETURN)
    {
      rtx op;

      /* A volatile function should never return.  Call abort.  */
      op = gen_rtx_SYMBOL_REF (Pmode, NEED_PLT_RELOC ? "abort(PLT)" : "abort");
      assemble_external_libcall (op);
      output_asm_insn ("bl\t%a0", &op);

      return "";
    }

  if (current_function_calls_eh_return
      && ! really_return)
    /* If we are throwing an exception, then we really must
       be doing a return,  so we can't tail-call.  */
    abort ();

  offsets = arm_get_frame_offsets ();
  saved_regs_mask = arm_compute_save_reg_mask ();

  if (TARGET_IWMMXT)
    lrm_count = bit_count (saved_regs_mask);

  floats_offset = offsets->saved_args;
  /* Compute how far away the floats will be.  */
  for (reg = 0; reg <= LAST_ARM_REGNUM; reg++)
    if (saved_regs_mask & (1 << reg))
      floats_offset += 4;

  if (frame_pointer_needed)
    {
      /* This variable is for the Virtual Frame Pointer, not VFP regs.  */
      int vfp_offset = offsets->frame;

      if (arm_fpu_arch == FPUTYPE_FPA_EMU2)
        {
          for (reg = LAST_FPA_REGNUM; reg >= FIRST_FPA_REGNUM; reg--)
            if (regs_ever_live[reg] && !call_used_regs[reg])
              {
                floats_offset += 12;
                asm_fprintf (f, "\tldfe\t%r, [%r, #-%d]\n",
                             reg, FP_REGNUM, floats_offset - vfp_offset);
              }
        }
      else
        {
          start_reg = LAST_FPA_REGNUM;

          for (reg = LAST_FPA_REGNUM; reg >= FIRST_FPA_REGNUM; reg--)
            {
              if (regs_ever_live[reg] && !call_used_regs[reg])
                {
                  floats_offset += 12;

                  /* We can't unstack more than four registers at once.  */
                  if (start_reg - reg == 3)
                    {
                      asm_fprintf (f, "\tlfm\t%r, 4, [%r, #-%d]\n",
                                   reg, FP_REGNUM, floats_offset - vfp_offset);
                      start_reg = reg - 1;
                    }
                }
              else
                {
                  if (reg != start_reg)
                    asm_fprintf (f, "\tlfm\t%r, %d, [%r, #-%d]\n",
                                 reg + 1, start_reg - reg,
                                 FP_REGNUM, floats_offset - vfp_offset);
                  start_reg = reg - 1;
                }
            }

          /* Just in case the last register checked also needs unstacking.  */
          if (reg != start_reg)
            asm_fprintf (f, "\tlfm\t%r, %d, [%r, #-%d]\n",
                         reg + 1, start_reg - reg,
                         FP_REGNUM, floats_offset - vfp_offset);
        }

      if (TARGET_HARD_FLOAT && TARGET_VFP)
        {
          int saved_size;

          /* The fldmx insn does not have base+offset addressing modes,
             so we use IP to hold the address.  */
          saved_size = arm_get_vfp_saved_size ();

          if (saved_size > 0)
            {
              floats_offset += saved_size;
              asm_fprintf (f, "\tsub\t%r, %r, #%d\n", IP_REGNUM,
                           FP_REGNUM, floats_offset - vfp_offset);
            }
          start_reg = FIRST_VFP_REGNUM;
          for (reg = FIRST_VFP_REGNUM; reg < LAST_VFP_REGNUM; reg += 2)
            {
              if ((!regs_ever_live[reg] || call_used_regs[reg])
                  && (!regs_ever_live[reg + 1] || call_used_regs[reg + 1]))
                {
                  if (start_reg != reg)
                    arm_output_fldmx (f, IP_REGNUM,
                                      (start_reg - FIRST_VFP_REGNUM) / 2,
                                      (reg - start_reg) / 2);
                  start_reg = reg + 2;
                }
            }
          if (start_reg != reg)
            arm_output_fldmx (f, IP_REGNUM,
                              (start_reg - FIRST_VFP_REGNUM) / 2,
                              (reg - start_reg) / 2);
        }

      if (TARGET_IWMMXT)
        {
          /* The frame pointer is guaranteed to be non-double-word aligned.
             This is because it is set to (old_stack_pointer - 4) and the
             old_stack_pointer was double word aligned.  Thus the offset to
             the iWMMXt registers to be loaded must also be non-double-word
             sized, so that the resultant address *is* double-word aligned.
             We can ignore floats_offset since that was already included in
             the live_regs_mask.  */
          lrm_count += (lrm_count % 2 ? 2 : 1);

          for (reg = LAST_IWMMXT_REGNUM; reg >= FIRST_IWMMXT_REGNUM; reg--)
            if (regs_ever_live[reg] && !call_used_regs[reg])
              {
                asm_fprintf (f, "\twldrd\t%r, [%r, #-%d]\n",
                             reg, FP_REGNUM, lrm_count * 4);
                lrm_count += 2;
              }
        }

      /* saved_regs_mask should contain the IP, which at the time of stack
         frame generation actually contains the old stack pointer.  So a
         quick way to unwind the stack is just pop the IP register directly
         into the stack pointer.  */
      if ((saved_regs_mask & (1 << IP_REGNUM)) == 0)
        abort ();
      saved_regs_mask &= ~ (1 << IP_REGNUM);
      saved_regs_mask |=   (1 << SP_REGNUM);

      /* There are two registers left in saved_regs_mask - LR and PC.  We
         only need to restore the LR register (the return address), but to
         save time we can load it directly into the PC, unless we need a
         special function exit sequence, or we are not really returning.  */
      if (really_return
          && ARM_FUNC_TYPE (func_type) == ARM_FT_NORMAL
          && !current_function_calls_eh_return)
        /* Delete the LR from the register mask, so that the LR on
           the stack is loaded into the PC in the register mask.  */
        saved_regs_mask &= ~ (1 << LR_REGNUM);
      else
        saved_regs_mask &= ~ (1 << PC_REGNUM);

      /* We must use SP as the base register, because SP is one of the
         registers being restored.  If an interrupt or page fault
         happens in the ldm instruction, the SP might or might not
         have been restored.  That would be bad, as then SP will no
         longer indicate the safe area of stack, and we can get stack
         corruption.  Using SP as the base register means that it will
         be reset correctly to the original value, should an interrupt
         occur.  If the stack pointer already points at the right
         place, then omit the subtraction.  */
      if (offsets->outgoing_args != (1 + (int) bit_count (saved_regs_mask))
          || current_function_calls_alloca)
        asm_fprintf (f, "\tsub\t%r, %r, #%d\n", SP_REGNUM, FP_REGNUM,
                     4 * bit_count (saved_regs_mask));
      print_multi_reg (f, "ldmfd\t%r", SP_REGNUM, saved_regs_mask);

      if (IS_INTERRUPT (func_type))
        /* Interrupt handlers will have pushed the
           IP onto the stack, so restore it now.  */
        print_multi_reg (f, "ldmfd\t%r!", SP_REGNUM, 1 << IP_REGNUM);
    }
  else
    {
      /* Restore stack pointer if necessary.  */
      if (offsets->outgoing_args != offsets->saved_regs)
        {
          operands[0] = operands[1] = stack_pointer_rtx;
          operands[2] = GEN_INT (offsets->outgoing_args - offsets->saved_regs);
          output_add_immediate (operands);
        }

      if (arm_fpu_arch == FPUTYPE_FPA_EMU2)
        {
          for (reg = FIRST_FPA_REGNUM; reg <= LAST_FPA_REGNUM; reg++)
            if (regs_ever_live[reg] && !call_used_regs[reg])
              asm_fprintf (f, "\tldfe\t%r, [%r], #12\n",
                           reg, SP_REGNUM);
        }
      else
        {
          start_reg = FIRST_FPA_REGNUM;

          for (reg = FIRST_FPA_REGNUM; reg <= LAST_FPA_REGNUM; reg++)
            {
              if (regs_ever_live[reg] && !call_used_regs[reg])
                {
                  if (reg - start_reg == 3)
                    {
                      asm_fprintf (f, "\tlfmfd\t%r, 4, [%r]!\n",
                                   start_reg, SP_REGNUM);
                      start_reg = reg + 1;
                    }
                }
              else
                {
                  if (reg != start_reg)
                    asm_fprintf (f, "\tlfmfd\t%r, %d, [%r]!\n",
                                 start_reg, reg - start_reg,
                                 SP_REGNUM);

                  start_reg = reg + 1;
                }
            }

          /* Just in case the last register checked also needs unstacking.  */
          if (reg != start_reg)
            asm_fprintf (f, "\tlfmfd\t%r, %d, [%r]!\n",
                         start_reg, reg - start_reg, SP_REGNUM);
        }

      if (TARGET_HARD_FLOAT && TARGET_VFP)
        {
          start_reg = FIRST_VFP_REGNUM;
          for (reg = FIRST_VFP_REGNUM; reg < LAST_VFP_REGNUM; reg += 2)
            {
              if ((!regs_ever_live[reg] || call_used_regs[reg])
                  && (!regs_ever_live[reg + 1] || call_used_regs[reg + 1]))
                {
                  if (start_reg != reg)
                    arm_output_fldmx (f, SP_REGNUM,
                                      (start_reg - FIRST_VFP_REGNUM) / 2,
                                      (reg - start_reg) / 2);
                  start_reg = reg + 2;
                }
            }
          if (start_reg != reg)
            arm_output_fldmx (f, SP_REGNUM,
                              (start_reg - FIRST_VFP_REGNUM) / 2,
                              (reg - start_reg) / 2);
        }
      if (TARGET_IWMMXT)
        for (reg = FIRST_IWMMXT_REGNUM; reg <= LAST_IWMMXT_REGNUM; reg++)
          if (regs_ever_live[reg] && !call_used_regs[reg])
            asm_fprintf (f, "\twldrd\t%r, [%r], #8\n", reg, SP_REGNUM);

      /* If we can, restore the LR into the PC.  */
      if (ARM_FUNC_TYPE (func_type) == ARM_FT_NORMAL
          && really_return
          && current_function_pretend_args_size == 0
          && saved_regs_mask & (1 << LR_REGNUM)
          && !current_function_calls_eh_return)
        {
          saved_regs_mask &= ~ (1 << LR_REGNUM);
          saved_regs_mask |=   (1 << PC_REGNUM);
        }

      /* Load the registers off the stack.  If we only have one register
         to load use the LDR instruction - it is faster.  */
      if (saved_regs_mask == (1 << LR_REGNUM))
        {
          asm_fprintf (f, "\tldr\t%r, [%r], #4\n", LR_REGNUM, SP_REGNUM);
        }
      else if (saved_regs_mask)
        {
          if (saved_regs_mask & (1 << SP_REGNUM))
            /* Note - write back to the stack register is not enabled
               (i.e. "ldmfd sp!...").  We know that the stack pointer is
               in the list of registers and if we add writeback the
               instruction becomes UNPREDICTABLE.  */
            print_multi_reg (f, "ldmfd\t%r", SP_REGNUM, saved_regs_mask);
          else
            print_multi_reg (f, "ldmfd\t%r!", SP_REGNUM, saved_regs_mask);
        }

      if (current_function_pretend_args_size)
        {
          /* Unwind the pre-pushed regs.  */
          operands[0] = operands[1] = stack_pointer_rtx;
          operands[2] = GEN_INT (current_function_pretend_args_size);
          output_add_immediate (operands);
        }
    }

  /* We may have already restored PC directly from the stack.  */
  if (!really_return || saved_regs_mask & (1 << PC_REGNUM))
    return "";

  /* Stack adjustment for exception handler.  */
  if (current_function_calls_eh_return)
    asm_fprintf (f, "\tadd\t%r, %r, %r\n", SP_REGNUM, SP_REGNUM,
                 ARM_EH_STACKADJ_REGNUM);

  /* Generate the return instruction.  */
  switch ((int) ARM_FUNC_TYPE (func_type))
    {
    case ARM_FT_ISR:
    case ARM_FT_FIQ:
      asm_fprintf (f, "\tsubs\t%r, %r, #4\n", PC_REGNUM, LR_REGNUM);
      break;

    case ARM_FT_EXCEPTION:
      asm_fprintf (f, "\tmovs\t%r, %r\n", PC_REGNUM, LR_REGNUM);
      break;

    case ARM_FT_INTERWORKED:
      asm_fprintf (f, "\tbx\t%r\n", LR_REGNUM);
      break;

    default:
      if (arm_arch5 || arm_arch4t)
        asm_fprintf (f, "\tbx\t%r\n", LR_REGNUM);
      else
        asm_fprintf (f, "\tmov\t%r, %r\n", PC_REGNUM, LR_REGNUM);
      break;
    }

  return "";
}

static void
arm_output_function_epilogue (FILE *file ATTRIBUTE_UNUSED,
                              HOST_WIDE_INT frame_size ATTRIBUTE_UNUSED)
{
  arm_stack_offsets *offsets;

  if (TARGET_THUMB)
    {
      int regno;

      /* Emit any call-via-reg trampolines that are needed for v4t support
         of call_reg and call_value_reg type insns.  */
      for (regno = 0; regno < LR_REGNUM; regno++)
        {
          rtx label = cfun->machine->call_via[regno];

          if (label != NULL)
            {
              function_section (current_function_decl);
              targetm.asm_out.internal_label (asm_out_file, "L",
                                              CODE_LABEL_NUMBER (label));
              asm_fprintf (asm_out_file, "\tbx\t%r\n", regno);
            }
        }

      /* ??? Probably not safe to set this here, since it assumes that a
         function will be emitted as assembly immediately after we generate
         RTL for it.  This does not happen for inline functions.  */
      return_used_this_function = 0;
    }
  else
    {
      /* We need to take into account any stack-frame rounding.  */
      offsets = arm_get_frame_offsets ();

      if (use_return_insn (FALSE, NULL)
          && return_used_this_function
          && offsets->saved_regs != offsets->outgoing_args
          && !frame_pointer_needed)
        abort ();

      /* Reset the ARM-specific per-function variables.  */
      after_arm_reorg = 0;
    }
}

/* Generate and emit an insn that we will recognize as a push_multi.
   Unfortunately, since this insn does not reflect very well the actual
   semantics of the operation, we need to annotate the insn for the benefit
   of DWARF2 frame unwind information.  */
static rtx
emit_multi_reg_push (unsigned long mask)
{
  int num_regs = 0;
  int num_dwarf_regs;
  int i, j;
  rtx par;
  rtx dwarf;
  int dwarf_par_index;
  rtx tmp, reg;

  for (i = 0; i <= LAST_ARM_REGNUM; i++)
    if (mask & (1 << i))
      num_regs++;

  if (num_regs == 0 || num_regs > 16)
    abort ();

  /* We don't record the PC in the dwarf frame information.  */
  num_dwarf_regs = num_regs;
  if (mask & (1 << PC_REGNUM))
    num_dwarf_regs--;

  /* For the body of the insn we are going to generate an UNSPEC in
     parallel with several USEs.  This allows the insn to be recognized
     by the push_multi pattern in the arm.md file.  The insn looks
     something like this:

       (parallel [
           (set (mem:BLK (pre_dec:BLK (reg:SI sp)))
                (unspec:BLK [(reg:SI r4)] UNSPEC_PUSH_MULT))
           (use (reg:SI 11 fp))
           (use (reg:SI 12 ip))
           (use (reg:SI 14 lr))
           (use (reg:SI 15 pc))
        ])

     For the frame note however, we try to be more explicit and actually
     show each register being stored into the stack frame, plus a (single)
     decrement of the stack pointer.  We do it this way in order to be
     friendly to the stack unwinding code, which only wants to see a single
     stack decrement per instruction.  The RTL we generate for the note looks
     something like this:

      (sequence [
           (set (reg:SI sp) (plus:SI (reg:SI sp) (const_int -20)))
           (set (mem:SI (reg:SI sp)) (reg:SI r4))
           (set (mem:SI (plus:SI (reg:SI sp) (const_int 4))) (reg:SI fp))
           (set (mem:SI (plus:SI (reg:SI sp) (const_int 8))) (reg:SI ip))
           (set (mem:SI (plus:SI (reg:SI sp) (const_int 12))) (reg:SI lr))
        ])

      This sequence is used both by the code to support stack unwinding for
      exceptions handlers and the code to generate dwarf2 frame debugging.  */

  par = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (num_regs));
  dwarf = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (num_dwarf_regs + 1));
  dwarf_par_index = 1;

  for (i = 0; i <= LAST_ARM_REGNUM; i++)
    {
      if (mask & (1 << i))
        {
          reg = gen_rtx_REG (SImode, i);

          XVECEXP (par, 0, 0)
            = gen_rtx_SET (VOIDmode,
                           gen_rtx_MEM (BLKmode,
                                        gen_rtx_PRE_DEC (BLKmode,
                                                         stack_pointer_rtx)),
                           gen_rtx_UNSPEC (BLKmode,
                                           gen_rtvec (1, reg),
                                           UNSPEC_PUSH_MULT));

          if (i != PC_REGNUM)
            {
              tmp = gen_rtx_SET (VOIDmode,
                                 gen_rtx_MEM (SImode, stack_pointer_rtx),
                                 reg);
              RTX_FRAME_RELATED_P (tmp) = 1;
              XVECEXP (dwarf, 0, dwarf_par_index) = tmp;
              dwarf_par_index++;
            }

          break;
        }
    }

  for (j = 1, i++; j < num_regs; i++)
    {
      if (mask & (1 << i))
        {
          reg = gen_rtx_REG (SImode, i);

          XVECEXP (par, 0, j) = gen_rtx_USE (VOIDmode, reg);

          if (i != PC_REGNUM)
            {
              tmp = gen_rtx_SET (VOIDmode,
                                 gen_rtx_MEM (SImode,
                                              plus_constant (stack_pointer_rtx,
                                                             4 * j)),
                                 reg);
              RTX_FRAME_RELATED_P (tmp) = 1;
              XVECEXP (dwarf, 0, dwarf_par_index++) = tmp;
            }

          j++;
        }
    }

  par = emit_insn (par);

  tmp = gen_rtx_SET (SImode,
                     stack_pointer_rtx,
                     gen_rtx_PLUS (SImode,
                                   stack_pointer_rtx,
                                   GEN_INT (-4 * num_regs)));
  RTX_FRAME_RELATED_P (tmp) = 1;
  XVECEXP (dwarf, 0, 0) = tmp;

  REG_NOTES (par) = gen_rtx_EXPR_LIST (REG_FRAME_RELATED_EXPR, dwarf,
                                       REG_NOTES (par));
  return par;
}

static rtx
emit_sfm (int base_reg, int count)
{
  rtx par;
  rtx dwarf;
  rtx tmp, reg;
  int i;

  par = gen_rtx_PARALLEL (VOIDmode, rtvec_alloc (count));
  dwarf = gen_rtx_SEQUENCE (VOIDmode, rtvec_alloc (count + 1));

  reg = gen_rtx_REG (XFmode, base_reg++);

  XVECEXP (par, 0, 0)
    = gen_rtx_SET (VOIDmode,
                   gen_rtx_MEM (BLKmode,
                                gen_rtx_PRE_DEC (BLKmode, stack_pointer_rtx)),
                   gen_rtx_UNSPEC (BLKmode,
                                   gen_rtvec (1, reg),
                                   UNSPEC_PUSH_MULT));
  tmp = gen_rtx_SET (VOIDmode,
                     gen_rtx_MEM (XFmode, stack_pointer_rtx), reg);
  RTX_FRAME_RELATED_P (tmp) = 1;
  XVECEXP (dwarf, 0, 1) = tmp;

  for (i = 1; i < count; i++)
    {
      reg = gen_rtx_REG (XFmode, base_reg++);
      XVECEXP (par, 0, i) = gen_rtx_USE (VOIDmode, reg);

      tmp = gen_rtx_SET (VOIDmode,
                         gen_rtx_MEM (XFmode,
                                      plus_constant (stack_pointer_rtx,
                                                     i * 12)),
                         reg);
      RTX_FRAME_RELATED_P (tmp) = 1;
      XVECEXP (dwarf, 0, i + 1) = tmp;
    }

  tmp = gen_rtx_SET (VOIDmode,
                     stack_pointer_rtx,
                     gen_rtx_PLUS (SImode,
                                   stack_pointer_rtx,
                                   GEN_INT (-12 * count)));
  RTX_FRAME_RELATED_P (tmp) = 1;
  XVECEXP (dwarf, 0, 0) = tmp;

  par = emit_insn (par);
  REG_NOTES (par) = gen_rtx_EXPR_LIST (REG_FRAME_RELATED_EXPR, dwarf,
                                       REG_NOTES (par));
  return par;
}


/* Return true if the current function needs to save/restore LR.  */

static bool
thumb_force_lr_save (void)
{
  return !cfun->machine->lr_save_eliminated
         && (!leaf_function_p ()
             || thumb_far_jump_used_p ()
             || regs_ever_live [LR_REGNUM]);
}


/* Compute the distance from register FROM to register TO.
   These can be the arg pointer (26), the soft frame pointer (25),
   the stack pointer (13) or the hard frame pointer (11).
   In thumb mode r7 is used as the soft frame pointer, if needed.
   Typical stack layout looks like this:

       old stack pointer -> |    |
                             ----
                            |    | \
                            |    |   saved arguments for
                            |    |   vararg functions
                            |    | /
                              --
   hard FP & arg pointer -> |    | \
                            |    |   stack
                            |    |   frame
                            |    | /
                              --
                            |    | \
                            |    |   call saved
                            |    |   registers
      soft frame pointer -> |    | /
                              --
                            |    | \
                            |    |   local
                            |    |   variables
                            |    | /
                              --
                            |    | \
                            |    |   outgoing
                            |    |   arguments
   current stack pointer -> |    | /
                              --

  For a given function some or all of these stack components
  may not be needed, giving rise to the possibility of
  eliminating some of the registers.

  The values returned by this function must reflect the behavior
  of arm_expand_prologue() and arm_compute_save_reg_mask().

  The sign of the number returned reflects the direction of stack
  growth, so the values are positive for all eliminations except
  from the soft frame pointer to the hard frame pointer.

  SFP may point just inside the local variables block to ensure correct
  alignment.  */


/* Calculate stack offsets.  These are used to calculate register elimination
   offsets and in prologue/epilogue code.  */

static arm_stack_offsets *
arm_get_frame_offsets (void)
{
  struct arm_stack_offsets *offsets;
  unsigned long func_type;
  int leaf;
  int saved;
  HOST_WIDE_INT frame_size;

  offsets = &cfun->machine->stack_offsets;

  /* We need to know if we are a leaf function.  Unfortunately, it
     is possible to be called after start_sequence has been called,
     which causes get_insns to return the insns for the sequence,
     not the function, which will cause leaf_function_p to return
     the incorrect result.

     to know about leaf functions once reload has completed, and the
     frame size cannot be changed after that time, so we can safely
     use the cached value.  */

  if (reload_completed)
    return offsets;

  /* Initially this is the size of the local variables.  It will translated
     into an offset once we have determined the size of preceding data.  */
  frame_size = ROUND_UP_WORD (get_frame_size ());

  leaf = leaf_function_p ();

  /* Space for variadic functions.  */
  offsets->saved_args = current_function_pretend_args_size;

  offsets->frame = offsets->saved_args + (frame_pointer_needed ? 4 : 0);

  if (TARGET_ARM)
    {
      unsigned int regno;

      saved = bit_count (arm_compute_save_reg_mask ()) * 4;

      /* We know that SP will be doubleword aligned on entry, and we must
         preserve that condition at any subroutine call.  We also require the
         soft frame pointer to be doubleword aligned.  */

      if (TARGET_REALLY_IWMMXT)
        {
          /* Check for the call-saved iWMMXt registers.  */
          for (regno = FIRST_IWMMXT_REGNUM;
               regno <= LAST_IWMMXT_REGNUM;
               regno++)
            if (regs_ever_live [regno] && ! call_used_regs [regno])
              saved += 8;
        }

      func_type = arm_current_func_type ();
      if (! IS_VOLATILE (func_type))
        {
          /* Space for saved FPA registers.  */
          for (regno = FIRST_FPA_REGNUM; regno <= LAST_FPA_REGNUM; regno++)
          if (regs_ever_live[regno] && ! call_used_regs[regno])
            saved += 12;

          /* Space for saved VFP registers.  */
          if (TARGET_HARD_FLOAT && TARGET_VFP)
            saved += arm_get_vfp_saved_size ();
        }
    }
  else /* TARGET_THUMB */
    {
      saved = bit_count (thumb_compute_save_reg_mask ()) * 4;
      if (TARGET_BACKTRACE)
        saved += 16;
    }

  /* Saved registers include the stack frame.  */
  offsets->saved_regs = offsets->saved_args + saved;
  offsets->soft_frame = offsets->saved_regs + CALLER_INTERWORKING_SLOT_SIZE;
  /* A leaf function does not need any stack alignment if it has nothing
     on the stack.  */
  if (leaf && frame_size == 0)
    {
      offsets->outgoing_args = offsets->soft_frame;
      return offsets;
    }

  /* Ensure SFP has the correct alignment.  */
  if (ARM_DOUBLEWORD_ALIGN
      && (offsets->soft_frame & 7))
    offsets->soft_frame += 4;

  offsets->outgoing_args = offsets->soft_frame + frame_size
                           + current_function_outgoing_args_size;

  if (ARM_DOUBLEWORD_ALIGN)
    {
      /* Ensure SP remains doubleword aligned.  */
      if (offsets->outgoing_args & 7)
        offsets->outgoing_args += 4;
      if (offsets->outgoing_args & 7)
        abort ();
    }

  return offsets;
}


/* Calculate the relative offsets for the different stack pointers.  Positive
   offsets are in the direction of stack growth.  */

HOST_WIDE_INT
arm_compute_initial_elimination_offset (unsigned int from, unsigned int to)
{
  arm_stack_offsets *offsets;

  offsets = arm_get_frame_offsets ();

  /* OK, now we have enough information to compute the distances.
     There must be an entry in these switch tables for each pair
     of registers in ELIMINABLE_REGS, even if some of the entries
     seem to be redundant or useless.  */
  switch (from)
    {
    case ARG_POINTER_REGNUM:
      switch (to)
        {
        case THUMB_HARD_FRAME_POINTER_REGNUM:
          return 0;

        case FRAME_POINTER_REGNUM:
          /* This is the reverse of the soft frame pointer
             to hard frame pointer elimination below.  */
          return offsets->soft_frame - offsets->saved_args;

        case ARM_HARD_FRAME_POINTER_REGNUM:
          /* If there is no stack frame then the hard
             frame pointer and the arg pointer coincide.  */
          if (offsets->frame == offsets->saved_regs)
            return 0;
          /* FIXME:  Not sure about this.  Maybe we should always return 0 ?  */
          return (frame_pointer_needed
                  && cfun->static_chain_decl != NULL
                  && ! cfun->machine->uses_anonymous_args) ? 4 : 0;

        case STACK_POINTER_REGNUM:
          /* If nothing has been pushed on the stack at all
             then this will return -4.  This *is* correct!  */
          return offsets->outgoing_args - (offsets->saved_args + 4);

        default:
          abort ();
        }
      break;

    case FRAME_POINTER_REGNUM:
      switch (to)
        {
        case THUMB_HARD_FRAME_POINTER_REGNUM:
          return 0;

        case ARM_HARD_FRAME_POINTER_REGNUM:
          /* The hard frame pointer points to the top entry in the
             stack frame.  The soft frame pointer to the bottom entry
             in the stack frame.  If there is no stack frame at all,
             then they are identical.  */

          return offsets->frame - offsets->soft_frame;

        case STACK_POINTER_REGNUM:
          return offsets->outgoing_args - offsets->soft_frame;

        default:
          abort ();
        }
      break;

    default:
      /* You cannot eliminate from the stack pointer.
         In theory you could eliminate from the hard frame
         pointer to the stack pointer, but this will never
         happen, since if a stack frame is not needed the
         hard frame pointer will never be used.  */
      abort ();
    }
}


/* Generate the prologue instructions for entry into an ARM function.  */
void
arm_expand_prologue (void)
{
  int reg;
  rtx amount;
  rtx insn;
  rtx ip_rtx;
  unsigned long live_regs_mask;
  unsigned long func_type;
  int fp_offset = 0;
  int saved_pretend_args = 0;
  int saved_regs = 0;
  unsigned HOST_WIDE_INT args_to_push;
  arm_stack_offsets *offsets;

  func_type = arm_current_func_type ();

  /* Naked functions don't have prologues.  */
  if (IS_NAKED (func_type))
    return;

  /* Make a copy of c_f_p_a_s as we may need to modify it locally.  */
  args_to_push = current_function_pretend_args_size;

  /* Compute which register we will have to save onto the stack.  */
  live_regs_mask = arm_compute_save_reg_mask ();

  ip_rtx = gen_rtx_REG (SImode, IP_REGNUM);

  if (frame_pointer_needed)
    {
      if (IS_INTERRUPT (func_type))
        {
          /* Interrupt functions must not corrupt any registers.
             Creating a frame pointer however, corrupts the IP
             register, so we must push it first.  */
          insn = emit_multi_reg_push (1 << IP_REGNUM);

          /* Do not set RTX_FRAME_RELATED_P on this insn.
             The dwarf stack unwinding code only wants to see one
             stack decrement per function, and this is not it.  If
             this instruction is labeled as being part of the frame
             creation sequence then dwarf2out_frame_debug_expr will
             abort when it encounters the assignment of IP to FP
             later on, since the use of SP here establishes SP as
             the CFA register and not IP.

             Anyway this instruction is not really part of the stack
             frame creation although it is part of the prologue.  */
        }
      else if (IS_NESTED (func_type))
        {
          /* The Static chain register is the same as the IP register
             used as a scratch register during stack frame creation.
             To get around this need to find somewhere to store IP
             whilst the frame is being created.  We try the following
             places in order:

               1. The last argument register.
               2. A slot on the stack above the frame.  (This only
                  works if the function is not a varargs function).
               3. Register r3, after pushing the argument registers
                  onto the stack.

             Note - we only need to tell the dwarf2 backend about the SP
             adjustment in the second variant; the static chain register
             doesn't need to be unwound, as it doesn't contain a value
             inherited from the caller.  */

          if (regs_ever_live[3] == 0)
            {
              insn = gen_rtx_REG (SImode, 3);
              insn = gen_rtx_SET (SImode, insn, ip_rtx);
              insn = emit_insn (insn);
            }
          else if (args_to_push == 0)
            {
              rtx dwarf;
              insn = gen_rtx_PRE_DEC (SImode, stack_pointer_rtx);
              insn = gen_rtx_MEM (SImode, insn);
              insn = gen_rtx_SET (VOIDmode, insn, ip_rtx);
              insn = emit_insn (insn);

              fp_offset = 4;

              /* Just tell the dwarf backend that we adjusted SP.  */
              dwarf = gen_rtx_SET (VOIDmode, stack_pointer_rtx,
                                   gen_rtx_PLUS (SImode, stack_pointer_rtx,
                                                 GEN_INT (-fp_offset)));
              RTX_FRAME_RELATED_P (insn) = 1;
              REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_FRAME_RELATED_EXPR,
                                                    dwarf, REG_NOTES (insn));
            }
          else
            {
              /* Store the args on the stack.  */
              if (cfun->machine->uses_anonymous_args)
                insn = emit_multi_reg_push
                  ((0xf0 >> (args_to_push / 4)) & 0xf);
              else
                insn = emit_insn
                  (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx,
                               GEN_INT (- args_to_push)));

              RTX_FRAME_RELATED_P (insn) = 1;

              saved_pretend_args = 1;
              fp_offset = args_to_push;
              args_to_push = 0;

              /* Now reuse r3 to preserve IP.  */
              insn = gen_rtx_REG (SImode, 3);
              insn = gen_rtx_SET (SImode, insn, ip_rtx);
              (void) emit_insn (insn);
            }
        }

      if (fp_offset)
        {
          insn = gen_rtx_PLUS (SImode, stack_pointer_rtx, GEN_INT (fp_offset));
          insn = gen_rtx_SET  (SImode, ip_rtx, insn);
        }
      else
        insn = gen_movsi (ip_rtx, stack_pointer_rtx);

      insn = emit_insn (insn);
      RTX_FRAME_RELATED_P (insn) = 1;
    }

  if (args_to_push)
    {
      /* Push the argument registers, or reserve space for them.  */
      if (cfun->machine->uses_anonymous_args)
        insn = emit_multi_reg_push
          ((0xf0 >> (args_to_push / 4)) & 0xf);
      else
        insn = emit_insn
          (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx,
                       GEN_INT (- args_to_push)));
      RTX_FRAME_RELATED_P (insn) = 1;
    }

  /* If this is an interrupt service routine, and the link register
     is going to be pushed, and we are not creating a stack frame,
     (which would involve an extra push of IP and a pop in the epilogue)
     subtracting four from LR now will mean that the function return
     can be done with a single instruction.  */
  if ((func_type == ARM_FT_ISR || func_type == ARM_FT_FIQ)
      && (live_regs_mask & (1 << LR_REGNUM)) != 0
      && ! frame_pointer_needed)
    emit_insn (gen_rtx_SET (SImode,
                            gen_rtx_REG (SImode, LR_REGNUM),
                            gen_rtx_PLUS (SImode,
                                          gen_rtx_REG (SImode, LR_REGNUM),
                                          GEN_INT (-4))));

  if (live_regs_mask)
    {
      insn = emit_multi_reg_push (live_regs_mask);
      saved_regs += bit_count (live_regs_mask) * 4;
      RTX_FRAME_RELATED_P (insn) = 1;
    }

  if (TARGET_IWMMXT)
    for (reg = LAST_IWMMXT_REGNUM; reg >= FIRST_IWMMXT_REGNUM; reg--)
      if (regs_ever_live[reg] && ! call_used_regs [reg])
        {
          insn = gen_rtx_PRE_DEC (V2SImode, stack_pointer_rtx);
          insn = gen_rtx_MEM (V2SImode, insn);
          insn = emit_insn (gen_rtx_SET (VOIDmode, insn,
                                         gen_rtx_REG (V2SImode, reg)));
          RTX_FRAME_RELATED_P (insn) = 1;
          saved_regs += 8;
        }

  if (! IS_VOLATILE (func_type))
    {
      int start_reg;

      /* Save any floating point call-saved registers used by this
         function.  */
      if (arm_fpu_arch == FPUTYPE_FPA_EMU2)
        {
          for (reg = LAST_FPA_REGNUM; reg >= FIRST_FPA_REGNUM; reg--)
            if (regs_ever_live[reg] && !call_used_regs[reg])
              {
                insn = gen_rtx_PRE_DEC (XFmode, stack_pointer_rtx);
                insn = gen_rtx_MEM (XFmode, insn);
                insn = emit_insn (gen_rtx_SET (VOIDmode, insn,
                                               gen_rtx_REG (XFmode, reg)));
                RTX_FRAME_RELATED_P (insn) = 1;
                saved_regs += 12;
              }
        }
      else
        {
          start_reg = LAST_FPA_REGNUM;

          for (reg = LAST_FPA_REGNUM; reg >= FIRST_FPA_REGNUM; reg--)
            {
              if (regs_ever_live[reg] && !call_used_regs[reg])
                {
                  if (start_reg - reg == 3)
                    {
                      insn = emit_sfm (reg, 4);
                      RTX_FRAME_RELATED_P (insn) = 1;
                      saved_regs += 48;
                      start_reg = reg - 1;
                    }
                }
              else
                {
                  if (start_reg != reg)
                    {
                      insn = emit_sfm (reg + 1, start_reg - reg);
                      RTX_FRAME_RELATED_P (insn) = 1;
                      saved_regs += (start_reg - reg) * 12;
                    }
                  start_reg = reg - 1;
                }
            }

          if (start_reg != reg)
            {
              insn = emit_sfm (reg + 1, start_reg - reg);
              saved_regs += (start_reg - reg) * 12;
              RTX_FRAME_RELATED_P (insn) = 1;
            }
        }
      if (TARGET_HARD_FLOAT && TARGET_VFP)
        {
          start_reg = FIRST_VFP_REGNUM;

          for (reg = FIRST_VFP_REGNUM; reg < LAST_VFP_REGNUM; reg += 2)
            {
              if ((!regs_ever_live[reg] || call_used_regs[reg])
                  && (!regs_ever_live[reg + 1] || call_used_regs[reg + 1]))
                {
                  if (start_reg != reg)
                    saved_regs += vfp_emit_fstmx (start_reg,
                                                  (reg - start_reg) / 2);
                  start_reg = reg + 2;
                }
            }
          if (start_reg != reg)
            saved_regs += vfp_emit_fstmx (start_reg,
                                          (reg - start_reg) / 2);
        }
    }

  if (frame_pointer_needed)
    {
      /* Create the new frame pointer.  */
      insn = GEN_INT (-(4 + args_to_push + fp_offset));
      insn = emit_insn (gen_addsi3 (hard_frame_pointer_rtx, ip_rtx, insn));
      RTX_FRAME_RELATED_P (insn) = 1;

      if (IS_NESTED (func_type))
        {
          /* Recover the static chain register.  */
          if (regs_ever_live [3] == 0
              || saved_pretend_args)
            insn = gen_rtx_REG (SImode, 3);
          else /* if (current_function_pretend_args_size == 0) */
            {
              insn = gen_rtx_PLUS (SImode, hard_frame_pointer_rtx,
                                   GEN_INT (4));
              insn = gen_rtx_MEM (SImode, insn);
            }

          emit_insn (gen_rtx_SET (SImode, ip_rtx, insn));
          /* Add a USE to stop propagate_one_insn() from barfing.  */
          emit_insn (gen_prologue_use (ip_rtx));
        }
    }

  offsets = arm_get_frame_offsets ();
  if (offsets->outgoing_args != offsets->saved_args + saved_regs)
    {
      /* This add can produce multiple insns for a large constant, so we
         need to get tricky.  */
      rtx last = get_last_insn ();

      amount = GEN_INT (offsets->saved_args + saved_regs
                        - offsets->outgoing_args);

      insn = emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx,
                                    amount));
      do
        {
          last = last ? NEXT_INSN (last) : get_insns ();
          RTX_FRAME_RELATED_P (last) = 1;
        }
      while (last != insn);

      /* If the frame pointer is needed, emit a special barrier that
         will prevent the scheduler from moving stores to the frame
         before the stack adjustment.  */
      if (frame_pointer_needed)
        insn = emit_insn (gen_stack_tie (stack_pointer_rtx,
                                         hard_frame_pointer_rtx));
    }


  if (flag_pic)
    arm_load_pic_register (INVALID_REGNUM);

  /* If we are profiling, make sure no instructions are scheduled before
     the call to mcount.  Similarly if the user has requested no
     scheduling in the prolog.  */
  if (current_function_profile || TARGET_NO_SCHED_PRO)
    emit_insn (gen_blockage ());

  /* If the link register is being kept alive, with the return address in it,
     then make sure that it does not get reused by the ce2 pass.  */
  if ((live_regs_mask & (1 << LR_REGNUM)) == 0)
    {
      emit_insn (gen_prologue_use (gen_rtx_REG (SImode, LR_REGNUM)));
      cfun->machine->lr_save_eliminated = 1;
    }
}
\f
/* If CODE is 'd', then the X is a condition operand and the instruction
   should only be executed if the condition is true.
   if CODE is 'D', then the X is a condition operand and the instruction
   should only be executed if the condition is false: however, if the mode
   of the comparison is CCFPEmode, then always execute the instruction -- we
   do this because in these circumstances !GE does not necessarily imply LT;
   in these cases the instruction pattern will take care to make sure that
   an instruction containing %d will follow, thereby undoing the effects of
   doing this instruction unconditionally.
   If CODE is 'N' then X is a floating point operand that must be negated
   before output.
   If CODE is 'B' then output a bitwise inverted value of X (a const int).
   If X is a REG and CODE is `M', output a ldm/stm style multi-reg.  */
void
arm_print_operand (FILE *stream, rtx x, int code)
{
  switch (code)
    {
    case '@':
      fputs (ASM_COMMENT_START, stream);
      return;

    case '_':
      fputs (user_label_prefix, stream);
      return;

    case '|':
      fputs (REGISTER_PREFIX, stream);
      return;

    case '?':
      if (arm_ccfsm_state == 3 || arm_ccfsm_state == 4)
        {
          if (TARGET_THUMB)
            {
              output_operand_lossage ("predicated Thumb instruction");
              break;
            }
          if (current_insn_predicate != NULL)
            {
              output_operand_lossage
                ("predicated instruction in conditional sequence");
              break;
            }

          fputs (arm_condition_codes[arm_current_cc], stream);
        }
      else if (current_insn_predicate)
        {
          enum arm_cond_code code;

          if (TARGET_THUMB)
            {
              output_operand_lossage ("predicated Thumb instruction");
              break;
            }

          code = get_arm_condition_code (current_insn_predicate);
          fputs (arm_condition_codes[code], stream);
        }
      return;

    case 'N':
      {
        REAL_VALUE_TYPE r;
        REAL_VALUE_FROM_CONST_DOUBLE (r, x);
        r = REAL_VALUE_NEGATE (r);
        fprintf (stream, "%s", fp_const_from_val (&r));
      }
      return;

    case 'B':
      if (GET_CODE (x) == CONST_INT)
        {
          HOST_WIDE_INT val;
          val = ARM_SIGN_EXTEND (~INTVAL (x));
          fprintf (stream, HOST_WIDE_INT_PRINT_DEC, val);
        }
      else
        {
          putc ('~', stream);
          output_addr_const (stream, x);
        }
      return;

    case 'i':
      fprintf (stream, "%s", arithmetic_instr (x, 1));
      return;

    /* Truncate Cirrus shift counts.  */
    case 's':
      if (GET_CODE (x) == CONST_INT)
        {
          fprintf (stream, HOST_WIDE_INT_PRINT_DEC, INTVAL (x) & 0x3f);
          return;
        }
      arm_print_operand (stream, x, 0);
      return;

    case 'I':
      fprintf (stream, "%s", arithmetic_instr (x, 0));
      return;

    case 'S':
      {
        HOST_WIDE_INT val;
        const char * shift = shift_op (x, &val);

        if (shift)
          {
            fprintf (stream, ", %s ", shift_op (x, &val));
            if (val == -1)
              arm_print_operand (stream, XEXP (x, 1), 0);
            else
              fprintf (stream, "#" HOST_WIDE_INT_PRINT_DEC, val);
          }
      }
      return;

      /* An explanation of the 'Q', 'R' and 'H' register operands:

         In a pair of registers containing a DI or DF value the 'Q'
         operand returns the register number of the register containing
         the least significant part of the value.  The 'R' operand returns
         the register number of the register containing the most
         significant part of the value.

         The 'H' operand returns the higher of the two register numbers.
         On a run where WORDS_BIG_ENDIAN is true the 'H' operand is the
         same as the 'Q' operand, since the most significant part of the
         value is held in the lower number register.  The reverse is true
         on systems where WORDS_BIG_ENDIAN is false.

         The purpose of these operands is to distinguish between cases
         where the endian-ness of the values is important (for example
         when they are added together), and cases where the endian-ness
         is irrelevant, but the order of register operations is important.
         For example when loading a value from memory into a register
         pair, the endian-ness does not matter.  Provided that the value
         from the lower memory address is put into the lower numbered
         register, and the value from the higher address is put into the
         higher numbered register, the load will work regardless of whether
         the value being loaded is big-wordian or little-wordian.  The
         order of the two register loads can matter however, if the address
         of the memory location is actually held in one of the registers
         being overwritten by the load.  */
    case 'Q':
      if (GET_CODE (x) != REG || REGNO (x) > LAST_ARM_REGNUM)
        {
          output_operand_lossage ("invalid operand for code '%c'", code);
          return;
        }

      asm_fprintf (stream, "%r", REGNO (x) + (WORDS_BIG_ENDIAN ? 1 : 0));
      return;

    case 'R':
      if (GET_CODE (x) != REG || REGNO (x) > LAST_ARM_REGNUM)
        {
          output_operand_lossage ("invalid operand for code '%c'", code);
          return;
        }

      asm_fprintf (stream, "%r", REGNO (x) + (WORDS_BIG_ENDIAN ? 0 : 1));
      return;

    case 'H':
      if (GET_CODE (x) != REG || REGNO (x) > LAST_ARM_REGNUM)
        {
          output_operand_lossage ("invalid operand for code '%c'", code);
          return;
        }

      asm_fprintf (stream, "%r", REGNO (x) + 1);
      return;

    case 'm':
      asm_fprintf (stream, "%r",
                   GET_CODE (XEXP (x, 0)) == REG
                   ? REGNO (XEXP (x, 0)) : REGNO (XEXP (XEXP (x, 0), 0)));
      return;

    case 'M':
      asm_fprintf (stream, "{%r-%r}",
                   REGNO (x),
                   REGNO (x) + ARM_NUM_REGS (GET_MODE (x)) - 1);
      return;

    case 'd':
      /* CONST_TRUE_RTX means always -- that's the default.  */
      if (x == const_true_rtx)
        return;

      if (!COMPARISON_P (x))
        {
          output_operand_lossage ("invalid operand for code '%c'", code);
          return;
        }

      fputs (arm_condition_codes[get_arm_condition_code (x)],
             stream);
      return;

    case 'D':
      /* CONST_TRUE_RTX means not always -- i.e. never.  We shouldn't ever
         want to do that.  */
      if (x == const_true_rtx)
        {
          output_operand_lossage ("instruction never exectued");
          return;
        }
      if (!COMPARISON_P (x))
        {
          output_operand_lossage ("invalid operand for code '%c'", code);
          return;
        }

      fputs (arm_condition_codes[ARM_INVERSE_CONDITION_CODE
                                 (get_arm_condition_code (x))],
             stream);
      return;

    /* Cirrus registers can be accessed in a variety of ways:
         single floating point (f)
         double floating point (d)
         32bit integer         (fx)
         64bit integer         (dx).  */
    case 'W':                   /* Cirrus register in F mode.  */
    case 'X':                   /* Cirrus register in D mode.  */
    case 'Y':                   /* Cirrus register in FX mode.  */
    case 'Z':                   /* Cirrus register in DX mode.  */
      if (GET_CODE (x) != REG || REGNO_REG_CLASS (REGNO (x)) != CIRRUS_REGS)
        abort ();

      fprintf (stream, "mv%s%s",
               code == 'W' ? "f"
               : code == 'X' ? "d"
               : code == 'Y' ? "fx" : "dx", reg_names[REGNO (x)] + 2);

      return;

    /* Print cirrus register in the mode specified by the register's mode.  */
    case 'V':
      {
        int mode = GET_MODE (x);

        if (GET_CODE (x) != REG || REGNO_REG_CLASS (REGNO (x)) != CIRRUS_REGS)
          {
            output_operand_lossage ("invalid operand for code '%c'", code);
            return;
          }

        fprintf (stream, "mv%s%s",
                 mode == DFmode ? "d"
                 : mode == SImode ? "fx"
                 : mode == DImode ? "dx"
                 : "f", reg_names[REGNO (x)] + 2);

        return;
      }

    case 'U':
      if (GET_CODE (x) != REG
          || REGNO (x) < FIRST_IWMMXT_GR_REGNUM
          || REGNO (x) > LAST_IWMMXT_GR_REGNUM)
        /* Bad value for wCG register number.  */
        {
          output_operand_lossage ("invalid operand for code '%c'", code);
          return;
        }

      else
        fprintf (stream, "%d", REGNO (x) - FIRST_IWMMXT_GR_REGNUM);
      return;

      /* Print an iWMMXt control register name.  */
    case 'w':
      if (GET_CODE (x) != CONST_INT
          || INTVAL (x) < 0
          || INTVAL (x) >= 16)
        /* Bad value for wC register number.  */
        {
          output_operand_lossage ("invalid operand for code '%c'", code);
          return;
        }

      else
        {
          static const char * wc_reg_names [16] =
            {
              "wCID",  "wCon",  "wCSSF", "wCASF",
              "wC4",   "wC5",   "wC6",   "wC7",
              "wCGR0", "wCGR1", "wCGR2", "wCGR3",
              "wC12",  "wC13",  "wC14",  "wC15"
            };

          fprintf (stream, wc_reg_names [INTVAL (x)]);
        }
      return;

      /* Print a VFP double precision register name.  */
    case 'P':
      {
        int mode = GET_MODE (x);
        int num;

        if (mode != DImode && mode != DFmode)
          {
            output_operand_lossage ("invalid operand for code '%c'", code);
            return;
          }

        if (GET_CODE (x) != REG
            || !IS_VFP_REGNUM (REGNO (x)))
          {
            output_operand_lossage ("invalid operand for code '%c'", code);
            return;
          }

        num = REGNO(x) - FIRST_VFP_REGNUM;
        if (num & 1)
          {
            output_operand_lossage ("invalid operand for code '%c'", code);
            return;
          }

        fprintf (stream, "d%d", num >> 1);
      }
      return;

    default:
      if (x == 0)
        {
          output_operand_lossage ("missing operand");
          return;
        }

      if (GET_CODE (x) == REG)
        asm_fprintf (stream, "%r", REGNO (x));
      else if (GET_CODE (x) == MEM)
        {
          output_memory_reference_mode = GET_MODE (x);
          output_address (XEXP (x, 0));
        }
      else if (GET_CODE (x) == CONST_DOUBLE)
        fprintf (stream, "#%s", fp_immediate_constant (x));
      else if (GET_CODE (x) == NEG)
        abort (); /* This should never happen now.  */
      else
        {
          fputc ('#', stream);
          output_addr_const (stream, x);
        }
    }
}
\f
#ifndef AOF_ASSEMBLER
/* Target hook for assembling integer objects.  The ARM version needs to
   handle word-sized values specially.  */
static bool
arm_assemble_integer (rtx x, unsigned int size, int aligned_p)
{
  if (size == UNITS_PER_WORD && aligned_p)
    {
      fputs ("\t.word\t", asm_out_file);
      output_addr_const (asm_out_file, x);

      /* Mark symbols as position independent.  We only do this in the
         .text segment, not in the .data segment.  */
      if (NEED_GOT_RELOC && flag_pic && making_const_table &&
          (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF))
        {
          if (GET_CODE (x) == SYMBOL_REF
              && (CONSTANT_POOL_ADDRESS_P (x)
                  || SYMBOL_REF_LOCAL_P (x)))
            fputs ("(GOTOFF)", asm_out_file);
          else if (GET_CODE (x) == LABEL_REF)
            fputs ("(GOTOFF)", asm_out_file);
          else
            fputs ("(GOT)", asm_out_file);
        }
      fputc ('\n', asm_out_file);
      return true;
    }

  if (arm_vector_mode_supported_p (GET_MODE (x)))
    {
      int i, units;

      if (GET_CODE (x) != CONST_VECTOR)
        abort ();

      units = CONST_VECTOR_NUNITS (x);

      switch (GET_MODE (x))
        {
        case V2SImode: size = 4; break;
        case V4HImode: size = 2; break;
        case V8QImode: size = 1; break;
        default:
          abort ();
        }

      for (i = 0; i < units; i++)
        {
          rtx elt;

          elt = CONST_VECTOR_ELT (x, i);
          assemble_integer
            (elt, size, i == 0 ? BIGGEST_ALIGNMENT : size * BITS_PER_UNIT, 1);
        }

      return true;
    }

  return default_assemble_integer (x, size, aligned_p);
}
#endif
\f
/* A finite state machine takes care of noticing whether or not instructions
   can be conditionally executed, and thus decrease execution time and code
   size by deleting branch instructions.  The fsm is controlled by
   final_prescan_insn, and controls the actions of ASM_OUTPUT_OPCODE.  */

/* The state of the fsm controlling condition codes are:
   0: normal, do nothing special
   1: make ASM_OUTPUT_OPCODE not output this instruction
   2: make ASM_OUTPUT_OPCODE not output this instruction
   3: make instructions conditional
   4: make instructions conditional

   State transitions (state->state by whom under condition):
   0 -> 1 final_prescan_insn if the `target' is a label
   0 -> 2 final_prescan_insn if the `target' is an unconditional branch
   1 -> 3 ASM_OUTPUT_OPCODE after not having output the conditional branch
   2 -> 4 ASM_OUTPUT_OPCODE after not having output the conditional branch
   3 -> 0 (*targetm.asm_out.internal_label) if the `target' label is reached
          (the target label has CODE_LABEL_NUMBER equal to arm_target_label).
   4 -> 0 final_prescan_insn if the `target' unconditional branch is reached
          (the target insn is arm_target_insn).

   If the jump clobbers the conditions then we use states 2 and 4.

   A similar thing can be done with conditional return insns.

   XXX In case the `target' is an unconditional branch, this conditionalising
   of the instructions always reduces code size, but not always execution
   time.  But then, I want to reduce the code size to somewhere near what
   /bin/cc produces.  */

/* Returns the index of the ARM condition code string in
   `arm_condition_codes'.  COMPARISON should be an rtx like
   `(eq (...) (...))'.  */
static enum arm_cond_code
get_arm_condition_code (rtx comparison)
{
  enum machine_mode mode = GET_MODE (XEXP (comparison, 0));
  int code;
  enum rtx_code comp_code = GET_CODE (comparison);

  if (GET_MODE_CLASS (mode) != MODE_CC)
    mode = SELECT_CC_MODE (comp_code, XEXP (comparison, 0),
                           XEXP (comparison, 1));

  switch (mode)
    {
    case CC_DNEmode: code = ARM_NE; goto dominance;
    case CC_DEQmode: code = ARM_EQ; goto dominance;
    case CC_DGEmode: code = ARM_GE; goto dominance;
    case CC_DGTmode: code = ARM_GT; goto dominance;
    case CC_DLEmode: code = ARM_LE; goto dominance;
    case CC_DLTmode: code = ARM_LT; goto dominance;
    case CC_DGEUmode: code = ARM_CS; goto dominance;
    case CC_DGTUmode: code = ARM_HI; goto dominance;
    case CC_DLEUmode: code = ARM_LS; goto dominance;
    case CC_DLTUmode: code = ARM_CC;

    dominance:
      if (comp_code != EQ && comp_code != NE)
        abort ();

      if (comp_code == EQ)
        return ARM_INVERSE_CONDITION_CODE (code);
      return code;

    case CC_NOOVmode:
      switch (comp_code)
        {
        case NE: return ARM_NE;
        case EQ: return ARM_EQ;
        case GE: return ARM_PL;
        case LT: return ARM_MI;
        default: abort ();
        }

    case CC_Zmode:
      switch (comp_code)
        {
        case NE: return ARM_NE;
        case EQ: return ARM_EQ;
        default: abort ();
        }

    case CC_Nmode:
      switch (comp_code)
        {
        case NE: return ARM_MI;
        case EQ: return ARM_PL;
        default: abort ();
        }

    case CCFPEmode:
    case CCFPmode:
      /* These encodings assume that AC=1 in the FPA system control
         byte.  This allows us to handle all cases except UNEQ and
         LTGT.  */
      switch (comp_code)
        {
        case GE: return ARM_GE;
        case GT: return ARM_GT;
        case LE: return ARM_LS;
        case LT: return ARM_MI;
        case NE: return ARM_NE;
        case EQ: return ARM_EQ;
        case ORDERED: return ARM_VC;
        case UNORDERED: return ARM_VS;
        case UNLT: return ARM_LT;
        case UNLE: return ARM_LE;
        case UNGT: return ARM_HI;
        case UNGE: return ARM_PL;
          /* UNEQ and LTGT do not have a representation.  */
        case UNEQ: /* Fall through.  */
        case LTGT: /* Fall through.  */
        default: abort ();
        }

    case CC_SWPmode:
      switch (comp_code)
        {
        case NE: return ARM_NE;
        case EQ: return ARM_EQ;
        case GE: return ARM_LE;
        case GT: return ARM_LT;
        case LE: return ARM_GE;
        case LT: return ARM_GT;
        case GEU: return ARM_LS;
        case GTU: return ARM_CC;
        case LEU: return ARM_CS;
        case LTU: return ARM_HI;
        default: abort ();
        }

    case CC_Cmode:
      switch (comp_code)
      {
      case LTU: return ARM_CS;
      case GEU: return ARM_CC;
      default: abort ();
      }

    case CCmode:
      switch (comp_code)
        {
        case NE: return ARM_NE;
        case EQ: return ARM_EQ;
        case GE: return ARM_GE;
        case GT: return ARM_GT;
        case LE: return ARM_LE;
        case LT: return ARM_LT;
        case GEU: return ARM_CS;
        case GTU: return ARM_HI;
        case LEU: return ARM_LS;
        case LTU: return ARM_CC;
        default: abort ();
        }

    default: abort ();
    }

  abort ();
}

void
arm_final_prescan_insn (rtx insn)
{
  /* BODY will hold the body of INSN.  */
  rtx body = PATTERN (insn);

  /* This will be 1 if trying to repeat the trick, and things need to be
     reversed if it appears to fail.  */
  int reverse = 0;

  /* JUMP_CLOBBERS will be one implies that the conditions if a branch is
     taken are clobbered, even if the rtl suggests otherwise.  It also
     means that we have to grub around within the jump expression to find
     out what the conditions are when the jump isn't taken.  */
  int jump_clobbers = 0;

  /* If we start with a return insn, we only succeed if we find another one.  */
  int seeking_return = 0;

  /* START_INSN will hold the insn from where we start looking.  This is the
     first insn after the following code_label if REVERSE is true.  */
  rtx start_insn = insn;

  /* If in state 4, check if the target branch is reached, in order to
     change back to state 0.  */
  if (arm_ccfsm_state == 4)
    {
      if (insn == arm_target_insn)
        {
          arm_target_insn = NULL;
          arm_ccfsm_state = 0;
        }
      return;
    }

  /* If in state 3, it is possible to repeat the trick, if this insn is an
     unconditional branch to a label, and immediately following this branch
     is the previous target label which is only used once, and the label this
     branch jumps to is not too far off.  */
  if (arm_ccfsm_state == 3)
    {
      if (simplejump_p (insn))
        {
          start_insn = next_nonnote_insn (start_insn);
          if (GET_CODE (start_insn) == BARRIER)
            {
              /* XXX Isn't this always a barrier?  */
              start_insn = next_nonnote_insn (start_insn);
            }
          if (GET_CODE (start_insn) == CODE_LABEL
              && CODE_LABEL_NUMBER (start_insn) == arm_target_label
              && LABEL_NUSES (start_insn) == 1)
            reverse = TRUE;
          else
            return;
        }
      else if (GET_CODE (body) == RETURN)
        {
          start_insn = next_nonnote_insn (start_insn);
          if (GET_CODE (start_insn) == BARRIER)
            start_insn = next_nonnote_insn (start_insn);
          if (GET_CODE (start_insn) == CODE_LABEL
              && CODE_LABEL_NUMBER (start_insn) == arm_target_label
              && LABEL_NUSES (start_insn) == 1)
            {
              reverse = TRUE;
              seeking_return = 1;
            }
          else
            return;
        }
      else
        return;
    }

  if (arm_ccfsm_state != 0 && !reverse)
    abort ();
  if (GET_CODE (insn) != JUMP_INSN)
    return;

  /* This jump might be paralleled with a clobber of the condition codes
     the jump should always come first */
  if (GET_CODE (body) == PARALLEL && XVECLEN (body, 0) > 0)
    body = XVECEXP (body, 0, 0);

  if (reverse
      || (GET_CODE (body) == SET && GET_CODE (SET_DEST (body)) == PC
          && GET_CODE (SET_SRC (body)) == IF_THEN_ELSE))
    {
      int insns_skipped;
      int fail = FALSE, succeed = FALSE;
      /* Flag which part of the IF_THEN_ELSE is the LABEL_REF.  */
      int then_not_else = TRUE;
      rtx this_insn = start_insn, label = 0;

      /* If the jump cannot be done with one instruction, we cannot
         conditionally execute the instruction in the inverse case.  */
      if (get_attr_conds (insn) == CONDS_JUMP_CLOB)
        {
          jump_clobbers = 1;
          return;
        }

      /* Register the insn jumped to.  */
      if (reverse)
        {
          if (!seeking_return)
            label = XEXP (SET_SRC (body), 0);
        }
      else if (GET_CODE (XEXP (SET_SRC (body), 1)) == LABEL_REF)
        label = XEXP (XEXP (SET_SRC (body), 1), 0);
      else if (GET_CODE (XEXP (SET_SRC (body), 2)) == LABEL_REF)
        {
          label = XEXP (XEXP (SET_SRC (body), 2), 0);
          then_not_else = FALSE;
        }
      else if (GET_CODE (XEXP (SET_SRC (body), 1)) == RETURN)
        seeking_return = 1;
      else if (GET_CODE (XEXP (SET_SRC (body), 2)) == RETURN)
        {
          seeking_return = 1;
          then_not_else = FALSE;
        }
      else
        abort ();

      /* See how many insns this branch skips, and what kind of insns.  If all
         insns are okay, and the label or unconditional branch to the same
         label is not too far away, succeed.  */
      for (insns_skipped = 0;
           !fail && !succeed && insns_skipped++ < max_insns_skipped;)
        {
          rtx scanbody;

          this_insn = next_nonnote_insn (this_insn);
          if (!this_insn)
            break;

          switch (GET_CODE (this_insn))
            {
            case CODE_LABEL:
              /* Succeed if it is the target label, otherwise fail since
                 control falls in from somewhere else.  */
              if (this_insn == label)
                {
                  if (jump_clobbers)
                    {
                      arm_ccfsm_state = 2;
                      this_insn = next_nonnote_insn (this_insn);
                    }
                  else
                    arm_ccfsm_state = 1;
                  succeed = TRUE;
                }
              else
                fail = TRUE;
              break;

            case BARRIER:
              /* Succeed if the following insn is the target label.
                 Otherwise fail.
                 If return insns are used then the last insn in a function
                 will be a barrier.  */
              this_insn = next_nonnote_insn (this_insn);
              if (this_insn && this_insn == label)
                {
                  if (jump_clobbers)
                    {
                      arm_ccfsm_state = 2;
                      this_insn = next_nonnote_insn (this_insn);
                    }
                  else
                    arm_ccfsm_state = 1;
                  succeed = TRUE;
                }
              else
                fail = TRUE;
              break;

            case CALL_INSN:
              /* The AAPCS says that conditional calls should not be
                 used since they make interworking inefficient (the
                 linker can't transform BL<cond> into BLX).  That's
                 only a problem if the machine has BLX.  */
              if (arm_arch5)
                {
                  fail = TRUE;
                  break;
                }

              /* Succeed if the following insn is the target label, or
                 if the following two insns are a barrier and the
                 target label.  */
              this_insn = next_nonnote_insn (this_insn);
              if (this_insn && GET_CODE (this_insn) == BARRIER)
                this_insn = next_nonnote_insn (this_insn);

              if (this_insn && this_insn == label
                  && insns_skipped < max_insns_skipped)
                {
                  if (jump_clobbers)
                    {
                      arm_ccfsm_state = 2;
                      this_insn = next_nonnote_insn (this_insn);
                    }
                  else
                    arm_ccfsm_state = 1;
                  succeed = TRUE;
                }
              else
                fail = TRUE;
              break;

            case JUMP_INSN:
              /* If this is an unconditional branch to the same label, succeed.
                 If it is to another label, do nothing.  If it is conditional,
                 fail.  */
              /* XXX Probably, the tests for SET and the PC are
                 unnecessary.  */

              scanbody = PATTERN (this_insn);
              if (GET_CODE (scanbody) == SET
                  && GET_CODE (SET_DEST (scanbody)) == PC)
                {
                  if (GET_CODE (SET_SRC (scanbody)) == LABEL_REF
                      && XEXP (SET_SRC (scanbody), 0) == label && !reverse)
                    {
                      arm_ccfsm_state = 2;
                      succeed = TRUE;
                    }
                  else if (GET_CODE (SET_SRC (scanbody)) == IF_THEN_ELSE)
                    fail = TRUE;
                }
              /* Fail if a conditional return is undesirable (e.g. on a
                 StrongARM), but still allow this if optimizing for size.  */
              else if (GET_CODE (scanbody) == RETURN
                       && !use_return_insn (TRUE, NULL)
                       && !optimize_size)
                fail = TRUE;
              else if (GET_CODE (scanbody) == RETURN
                       && seeking_return)
                {
                  arm_ccfsm_state = 2;
                  succeed = TRUE;
                }
              else if (GET_CODE (scanbody) == PARALLEL)
                {
                  switch (get_attr_conds (this_insn))
                    {
                    case CONDS_NOCOND:
                      break;
                    default:
                      fail = TRUE;
                      break;
                    }
                }
              else
                fail = TRUE;    /* Unrecognized jump (e.g. epilogue).  */

              break;

            case INSN:
              /* Instructions using or affecting the condition codes make it
                 fail.  */
              scanbody = PATTERN (this_insn);
              if (!(GET_CODE (scanbody) == SET
                    || GET_CODE (scanbody) == PARALLEL)
                  || get_attr_conds (this_insn) != CONDS_NOCOND)
                fail = TRUE;

              /* A conditional cirrus instruction must be followed by
                 a non Cirrus instruction.  However, since we
                 conditionalize instructions in this function and by
                 the time we get here we can't add instructions
                 (nops), because shorten_branches() has already been
                 called, we will disable conditionalizing Cirrus
                 instructions to be safe.  */
              if (GET_CODE (scanbody) != USE
                  && GET_CODE (scanbody) != CLOBBER
                  && get_attr_cirrus (this_insn) != CIRRUS_NOT)
                fail = TRUE;
              break;

            default:
              break;
            }
        }
      if (succeed)
        {
          if ((!seeking_return) && (arm_ccfsm_state == 1 || reverse))
            arm_target_label = CODE_LABEL_NUMBER (label);
          else if (seeking_return || arm_ccfsm_state == 2)
            {
              while (this_insn && GET_CODE (PATTERN (this_insn)) == USE)
                {
                  this_insn = next_nonnote_insn (this_insn);
                  if (this_insn && (GET_CODE (this_insn) == BARRIER
                                    || GET_CODE (this_insn) == CODE_LABEL))
                    abort ();
                }
              if (!this_insn)
                {
                  /* Oh, dear! we ran off the end.. give up.  */
                  recog (PATTERN (insn), insn, NULL);
                  arm_ccfsm_state = 0;
                  arm_target_insn = NULL;
                  return;
                }
              arm_target_insn = this_insn;
            }
          else
            abort ();
          if (jump_clobbers)
            {
              if (reverse)
                abort ();
              arm_current_cc =
                  get_arm_condition_code (XEXP (XEXP (XEXP (SET_SRC (body),
                                                            0), 0), 1));
              if (GET_CODE (XEXP (XEXP (SET_SRC (body), 0), 0)) == AND)
                arm_current_cc = ARM_INVERSE_CONDITION_CODE (arm_current_cc);
              if (GET_CODE (XEXP (SET_SRC (body), 0)) == NE)
                arm_current_cc = ARM_INVERSE_CONDITION_CODE (arm_current_cc);
            }
          else
            {
              /* If REVERSE is true, ARM_CURRENT_CC needs to be inverted from
                 what it was.  */
              if (!reverse)
                arm_current_cc = get_arm_condition_code (XEXP (SET_SRC (body),
                                                               0));
            }

          if (reverse || then_not_else)
            arm_current_cc = ARM_INVERSE_CONDITION_CODE (arm_current_cc);
        }

      /* Restore recog_data (getting the attributes of other insns can
         destroy this array, but final.c assumes that it remains intact
         across this call; since the insn has been recognized already we
         call recog direct).  */
      recog (PATTERN (insn), insn, NULL);
    }
}

/* Returns true if REGNO is a valid register
   for holding a quantity of type MODE.  */
int
arm_hard_regno_mode_ok (unsigned int regno, enum machine_mode mode)
{
  if (GET_MODE_CLASS (mode) == MODE_CC)
    return regno == CC_REGNUM || regno == VFPCC_REGNUM;

  if (TARGET_THUMB)
    /* For the Thumb we only allow values bigger than SImode in
       registers 0 - 6, so that there is always a second low
       register available to hold the upper part of the value.
       We probably we ought to ensure that the register is the
       start of an even numbered register pair.  */
    return (ARM_NUM_REGS (mode) < 2) || (regno < LAST_LO_REGNUM);

  if (IS_CIRRUS_REGNUM (regno))
    /* We have outlawed SI values in Cirrus registers because they
       reside in the lower 32 bits, but SF values reside in the
       upper 32 bits.  This causes gcc all sorts of grief.  We can't
       even split the registers into pairs because Cirrus SI values
       get sign extended to 64bits-- aldyh.  */
    return (GET_MODE_CLASS (mode) == MODE_FLOAT) || (mode == DImode);

  if (IS_VFP_REGNUM (regno))
    {
      if (mode == SFmode || mode == SImode)
        return TRUE;

      /* DFmode values are only valid in even register pairs.  */
      if (mode == DFmode)
        return ((regno - FIRST_VFP_REGNUM) & 1) == 0;
      return FALSE;
    }

  if (IS_IWMMXT_GR_REGNUM (regno))
    return mode == SImode;

  if (IS_IWMMXT_REGNUM (regno))
    return VALID_IWMMXT_REG_MODE (mode);

  /* We allow any value to be stored in the general registers.
     Restrict doubleword quantities to even register pairs so that we can
     use ldrd.  */
  if (regno <= LAST_ARM_REGNUM)
    return !(TARGET_LDRD && GET_MODE_SIZE (mode) > 4 && (regno & 1) != 0);

  if (   regno == FRAME_POINTER_REGNUM
      || regno == ARG_POINTER_REGNUM)
    /* We only allow integers in the fake hard registers.  */
    return GET_MODE_CLASS (mode) == MODE_INT;

  /* The only registers left are the FPA registers
     which we only allow to hold FP values.  */
  return GET_MODE_CLASS (mode) == MODE_FLOAT
    && regno >= FIRST_FPA_REGNUM
    && regno <= LAST_FPA_REGNUM;
}

int
arm_regno_class (int regno)
{
  if (TARGET_THUMB)
    {
      if (regno == STACK_POINTER_REGNUM)
        return STACK_REG;
      if (regno == CC_REGNUM)
        return CC_REG;
      if (regno < 8)
        return LO_REGS;
      return HI_REGS;
    }

  if (   regno <= LAST_ARM_REGNUM
      || regno == FRAME_POINTER_REGNUM
      || regno == ARG_POINTER_REGNUM)
    return GENERAL_REGS;

  if (regno == CC_REGNUM || regno == VFPCC_REGNUM)
    return NO_REGS;

  if (IS_CIRRUS_REGNUM (regno))
    return CIRRUS_REGS;

  if (IS_VFP_REGNUM (regno))
    return VFP_REGS;

  if (IS_IWMMXT_REGNUM (regno))
    return IWMMXT_REGS;

  if (IS_IWMMXT_GR_REGNUM (regno))
    return IWMMXT_GR_REGS;

  return FPA_REGS;
}

/* Handle a special case when computing the offset
   of an argument from the frame pointer.  */
int
arm_debugger_arg_offset (int value, rtx addr)
{
  rtx insn;

  /* We are only interested if dbxout_parms() failed to compute the offset.  */
  if (value != 0)
    return 0;

  /* We can only cope with the case where the address is held in a register.  */
  if (GET_CODE (addr) != REG)
    return 0;

  /* If we are using the frame pointer to point at the argument, then
     an offset of 0 is correct.  */
  if (REGNO (addr) == (unsigned) HARD_FRAME_POINTER_REGNUM)
    return 0;

  /* If we are using the stack pointer to point at the
     argument, then an offset of 0 is correct.  */
  if ((TARGET_THUMB || !frame_pointer_needed)
      && REGNO (addr) == SP_REGNUM)
    return 0;

  /* Oh dear.  The argument is pointed to by a register rather
     than being held in a register, or being stored at a known
     offset from the frame pointer.  Since GDB only understands
     those two kinds of argument we must translate the address
     held in the register into an offset from the frame pointer.
     We do this by searching through the insns for the function
     looking to see where this register gets its value.  If the
     register is initialized from the frame pointer plus an offset
     then we are in luck and we can continue, otherwise we give up.

     This code is exercised by producing debugging information
     for a function with arguments like this:

           double func (double a, double b, int c, double d) {return d;}

     Without this code the stab for parameter 'd' will be set to
     an offset of 0 from the frame pointer, rather than 8.  */

  /* The if() statement says:

     If the insn is a normal instruction
     and if the insn is setting the value in a register
     and if the register being set is the register holding the address of the argument
     and if the address is computing by an addition
     that involves adding to a register
     which is the frame pointer
     a constant integer

     then...  */

  for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
    {
      if (   GET_CODE (insn) == INSN
          && GET_CODE (PATTERN (insn)) == SET
          && REGNO    (XEXP (PATTERN (insn), 0)) == REGNO (addr)
          && GET_CODE (XEXP (PATTERN (insn), 1)) == PLUS
          && GET_CODE (XEXP (XEXP (PATTERN (insn), 1), 0)) == REG
          && REGNO    (XEXP (XEXP (PATTERN (insn), 1), 0)) == (unsigned) HARD_FRAME_POINTER_REGNUM
          && GET_CODE (XEXP (XEXP (PATTERN (insn), 1), 1)) == CONST_INT
             )
        {
          value = INTVAL (XEXP (XEXP (PATTERN (insn), 1), 1));

          break;
        }
    }

  if (value == 0)
    {
      debug_rtx (addr);
      warning (0, "unable to compute real location of stacked parameter");
      value = 8; /* XXX magic hack */
    }

  return value;
}
\f
#define def_mbuiltin(MASK, NAME, TYPE, CODE)                            \
  do                                                                    \
    {                                                                   \
      if ((MASK) & insn_flags)                                          \
        lang_hooks.builtin_function ((NAME), (TYPE), (CODE),            \
                                     BUILT_IN_MD, NULL, NULL_TREE);     \
    }                                                                   \
  while (0)

struct builtin_description
{
  const unsigned int       mask;
  const enum insn_code     icode;
  const char * const       name;
  const enum arm_builtins  code;
  const enum rtx_code      comparison;
  const unsigned int       flag;
};

static const struct builtin_description bdesc_2arg[] =
{
#define IWMMXT_BUILTIN(code, string, builtin) \
  { FL_IWMMXT, CODE_FOR_##code, "__builtin_arm_" string, \
    ARM_BUILTIN_##builtin, 0, 0 },

  IWMMXT_BUILTIN (addv8qi3, "waddb", WADDB)
  IWMMXT_BUILTIN (addv4hi3, "waddh", WADDH)
  IWMMXT_BUILTIN (addv2si3, "waddw", WADDW)
  IWMMXT_BUILTIN (subv8qi3, "wsubb", WSUBB)
  IWMMXT_BUILTIN (subv4hi3, "wsubh", WSUBH)
  IWMMXT_BUILTIN (subv2si3, "wsubw", WSUBW)
  IWMMXT_BUILTIN (ssaddv8qi3, "waddbss", WADDSSB)
  IWMMXT_BUILTIN (ssaddv4hi3, "waddhss", WADDSSH)
  IWMMXT_BUILTIN (ssaddv2si3, "waddwss", WADDSSW)
  IWMMXT_BUILTIN (sssubv8qi3, "wsubbss", WSUBSSB)
  IWMMXT_BUILTIN (sssubv4hi3, "wsubhss", WSUBSSH)
  IWMMXT_BUILTIN (sssubv2si3, "wsubwss", WSUBSSW)
  IWMMXT_BUILTIN (usaddv8qi3, "waddbus", WADDUSB)
  IWMMXT_BUILTIN (usaddv4hi3, "waddhus", WADDUSH)
  IWMMXT_BUILTIN (usaddv2si3, "waddwus", WADDUSW)
  IWMMXT_BUILTIN (ussubv8qi3, "wsubbus", WSUBUSB)
  IWMMXT_BUILTIN (ussubv4hi3, "wsubhus", WSUBUSH)
  IWMMXT_BUILTIN (ussubv2si3, "wsubwus", WSUBUSW)
  IWMMXT_BUILTIN (mulv4hi3, "wmulul", WMULUL)
  IWMMXT_BUILTIN (smulv4hi3_highpart, "wmulsm", WMULSM)
  IWMMXT_BUILTIN (umulv4hi3_highpart, "wmulum", WMULUM)
  IWMMXT_BUILTIN (eqv8qi3, "wcmpeqb", WCMPEQB)
  IWMMXT_BUILTIN (eqv4hi3, "wcmpeqh", WCMPEQH)
  IWMMXT_BUILTIN (eqv2si3, "wcmpeqw", WCMPEQW)
  IWMMXT_BUILTIN (gtuv8qi3, "wcmpgtub", WCMPGTUB)
  IWMMXT_BUILTIN (gtuv4hi3, "wcmpgtuh", WCMPGTUH)
  IWMMXT_BUILTIN (gtuv2si3, "wcmpgtuw", WCMPGTUW)
  IWMMXT_BUILTIN (gtv8qi3, "wcmpgtsb", WCMPGTSB)
  IWMMXT_BUILTIN (gtv4hi3, "wcmpgtsh", WCMPGTSH)
  IWMMXT_BUILTIN (gtv2si3, "wcmpgtsw", WCMPGTSW)
  IWMMXT_BUILTIN (umaxv8qi3, "wmaxub", WMAXUB)
  IWMMXT_BUILTIN (smaxv8qi3, "wmaxsb", WMAXSB)
  IWMMXT_BUILTIN (umaxv4hi3, "wmaxuh", WMAXUH)
  IWMMXT_BUILTIN (smaxv4hi3, "wmaxsh", WMAXSH)
  IWMMXT_BUILTIN (umaxv2si3, "wmaxuw", WMAXUW)
  IWMMXT_BUILTIN (smaxv2si3, "wmaxsw", WMAXSW)
  IWMMXT_BUILTIN (uminv8qi3, "wminub", WMINUB)
  IWMMXT_BUILTIN (sminv8qi3, "wminsb", WMINSB)
  IWMMXT_BUILTIN (uminv4hi3, "wminuh", WMINUH)
  IWMMXT_BUILTIN (sminv4hi3, "wminsh", WMINSH)
  IWMMXT_BUILTIN (uminv2si3, "wminuw", WMINUW)
  IWMMXT_BUILTIN (sminv2si3, "wminsw", WMINSW)
  IWMMXT_BUILTIN (iwmmxt_anddi3, "wand", WAND)
  IWMMXT_BUILTIN (iwmmxt_nanddi3, "wandn", WANDN)
  IWMMXT_BUILTIN (iwmmxt_iordi3, "wor", WOR)
  IWMMXT_BUILTIN (iwmmxt_xordi3, "wxor", WXOR)
  IWMMXT_BUILTIN (iwmmxt_uavgv8qi3, "wavg2b", WAVG2B)
  IWMMXT_BUILTIN (iwmmxt_uavgv4hi3, "wavg2h", WAVG2H)
  IWMMXT_BUILTIN (iwmmxt_uavgrndv8qi3, "wavg2br", WAVG2BR)
  IWMMXT_BUILTIN (iwmmxt_uavgrndv4hi3, "wavg2hr", WAVG2HR)
  IWMMXT_BUILTIN (iwmmxt_wunpckilb, "wunpckilb", WUNPCKILB)
  IWMMXT_BUILTIN (iwmmxt_wunpckilh, "wunpckilh", WUNPCKILH)
  IWMMXT_BUILTIN (iwmmxt_wunpckilw, "wunpckilw", WUNPCKILW)
  IWMMXT_BUILTIN (iwmmxt_wunpckihb, "wunpckihb", WUNPCKIHB)
  IWMMXT_BUILTIN (iwmmxt_wunpckihh, "wunpckihh", WUNPCKIHH)
  IWMMXT_BUILTIN (iwmmxt_wunpckihw, "wunpckihw", WUNPCKIHW)
  IWMMXT_BUILTIN (iwmmxt_wmadds, "wmadds", WMADDS)
  IWMMXT_BUILTIN (iwmmxt_wmaddu, "wmaddu", WMADDU)

#define IWMMXT_BUILTIN2(code, builtin) \
  { FL_IWMMXT, CODE_FOR_##code, NULL, ARM_BUILTIN_##builtin, 0, 0 },

  IWMMXT_BUILTIN2 (iwmmxt_wpackhss, WPACKHSS)
  IWMMXT_BUILTIN2 (iwmmxt_wpackwss, WPACKWSS)
  IWMMXT_BUILTIN2 (iwmmxt_wpackdss, WPACKDSS)
  IWMMXT_BUILTIN2 (iwmmxt_wpackhus, WPACKHUS)
  IWMMXT_BUILTIN2 (iwmmxt_wpackwus, WPACKWUS)
  IWMMXT_BUILTIN2 (iwmmxt_wpackdus, WPACKDUS)
  IWMMXT_BUILTIN2 (ashlv4hi3_di,    WSLLH)
  IWMMXT_BUILTIN2 (ashlv4hi3,       WSLLHI)
  IWMMXT_BUILTIN2 (ashlv2si3_di,    WSLLW)
  IWMMXT_BUILTIN2 (ashlv2si3,       WSLLWI)
  IWMMXT_BUILTIN2 (ashldi3_di,      WSLLD)
  IWMMXT_BUILTIN2 (ashldi3_iwmmxt,  WSLLDI)
  IWMMXT_BUILTIN2 (lshrv4hi3_di,    WSRLH)
  IWMMXT_BUILTIN2 (lshrv4hi3,       WSRLHI)
  IWMMXT_BUILTIN2 (lshrv2si3_di,    WSRLW)
  IWMMXT_BUILTIN2 (lshrv2si3,       WSRLWI)
  IWMMXT_BUILTIN2 (lshrdi3_di,      WSRLD)
  IWMMXT_BUILTIN2 (lshrdi3_iwmmxt,  WSRLDI)
  IWMMXT_BUILTIN2 (ashrv4hi3_di,    WSRAH)
  IWMMXT_BUILTIN2 (ashrv4hi3,       WSRAHI)
  IWMMXT_BUILTIN2 (ashrv2si3_di,    WSRAW)
  IWMMXT_BUILTIN2 (ashrv2si3,       WSRAWI)
  IWMMXT_BUILTIN2 (ashrdi3_di,      WSRAD)
  IWMMXT_BUILTIN2 (ashrdi3_iwmmxt,  WSRADI)
  IWMMXT_BUILTIN2 (rorv4hi3_di,     WRORH)
  IWMMXT_BUILTIN2 (rorv4hi3,        WRORHI)
  IWMMXT_BUILTIN2 (rorv2si3_di,     WRORW)
  IWMMXT_BUILTIN2 (rorv2si3,        WRORWI)
  IWMMXT_BUILTIN2 (rordi3_di,       WRORD)
  IWMMXT_BUILTIN2 (rordi3,          WRORDI)
  IWMMXT_BUILTIN2 (iwmmxt_wmacuz,   WMACUZ)
  IWMMXT_BUILTIN2 (iwmmxt_wmacsz,   WMACSZ)
};

static const struct builtin_description bdesc_1arg[] =
{
  IWMMXT_BUILTIN (iwmmxt_tmovmskb, "tmovmskb", TMOVMSKB)
  IWMMXT_BUILTIN (iwmmxt_tmovmskh, "tmovmskh", TMOVMSKH)
  IWMMXT_BUILTIN (iwmmxt_tmovmskw, "tmovmskw", TMOVMSKW)
  IWMMXT_BUILTIN (iwmmxt_waccb, "waccb", WACCB)
  IWMMXT_BUILTIN (iwmmxt_wacch, "wacch", WACCH)
  IWMMXT_BUILTIN (iwmmxt_waccw, "waccw", WACCW)
  IWMMXT_BUILTIN (iwmmxt_wunpckehub, "wunpckehub", WUNPCKEHUB)
  IWMMXT_BUILTIN (iwmmxt_wunpckehuh, "wunpckehuh", WUNPCKEHUH)
  IWMMXT_BUILTIN (iwmmxt_wunpckehuw, "wunpckehuw", WUNPCKEHUW)
  IWMMXT_BUILTIN (iwmmxt_wunpckehsb, "wunpckehsb", WUNPCKEHSB)
  IWMMXT_BUILTIN (iwmmxt_wunpckehsh, "wunpckehsh", WUNPCKEHSH)
  IWMMXT_BUILTIN (iwmmxt_wunpckehsw, "wunpckehsw", WUNPCKEHSW)
  IWMMXT_BUILTIN (iwmmxt_wunpckelub, "wunpckelub", WUNPCKELUB)
  IWMMXT_BUILTIN (iwmmxt_wunpckeluh, "wunpckeluh", WUNPCKELUH)
  IWMMXT_BUILTIN (iwmmxt_wunpckeluw, "wunpckeluw", WUNPCKELUW)
  IWMMXT_BUILTIN (iwmmxt_wunpckelsb, "wunpckelsb", WUNPCKELSB)
  IWMMXT_BUILTIN (iwmmxt_wunpckelsh, "wunpckelsh", WUNPCKELSH)
  IWMMXT_BUILTIN (iwmmxt_wunpckelsw, "wunpckelsw", WUNPCKELSW)
};

/* Set up all the iWMMXt builtins.  This is
   not called if TARGET_IWMMXT is zero.  */

static void
arm_init_iwmmxt_builtins (void)
{
  const struct builtin_description * d;
  size_t i;
  tree endlink = void_list_node;

  tree V2SI_type_node = build_vector_type_for_mode (intSI_type_node, V2SImode);
  tree V4HI_type_node = build_vector_type_for_mode (intHI_type_node, V4HImode);
  tree V8QI_type_node = build_vector_type_for_mode (intQI_type_node, V8QImode);

  tree int_ftype_int
    = build_function_type (integer_type_node,
                           tree_cons (NULL_TREE, integer_type_node, endlink));
  tree v8qi_ftype_v8qi_v8qi_int
    = build_function_type (V8QI_type_node,
                           tree_cons (NULL_TREE, V8QI_type_node,
                                      tree_cons (NULL_TREE, V8QI_type_node,
                                                 tree_cons (NULL_TREE,
                                                            integer_type_node,
                                                            endlink))));
  tree v4hi_ftype_v4hi_int
    = build_function_type (V4HI_type_node,
                           tree_cons (NULL_TREE, V4HI_type_node,
                                      tree_cons (NULL_TREE, integer_type_node,
                                                 endlink)));
  tree v2si_ftype_v2si_int
    = build_function_type (V2SI_type_node,
                           tree_cons (NULL_TREE, V2SI_type_node,
                                      tree_cons (NULL_TREE, integer_type_node,
                                                 endlink)));
  tree v2si_ftype_di_di
    = build_function_type (V2SI_type_node,
                           tree_cons (NULL_TREE, long_long_integer_type_node,
                                      tree_cons (NULL_TREE, long_long_integer_type_node,
                                                 endlink)));
  tree di_ftype_di_int
    = build_function_type (long_long_integer_type_node,
                           tree_cons (NULL_TREE, long_long_integer_type_node,
                                      tree_cons (NULL_TREE, integer_type_node,
                                                 endlink)));
  tree di_ftype_di_int_int
    = build_function_type (long_long_integer_type_node,
                           tree_cons (NULL_TREE, long_long_integer_type_node,
                                      tree_cons (NULL_TREE, integer_type_node,
                                                 tree_cons (NULL_TREE,
                                                            integer_type_node,
                                                            endlink))));
  tree int_ftype_v8qi
    = build_function_type (integer_type_node,
                           tree_cons (NULL_TREE, V8QI_type_node,
                                      endlink));
  tree int_ftype_v4hi
    = build_function_type (integer_type_node,
                           tree_cons (NULL_TREE, V4HI_type_node,
                                      endlink));
  tree int_ftype_v2si
    = build_function_type (integer_type_node,
                           tree_cons (NULL_TREE, V2SI_type_node,
                                      endlink));
  tree int_ftype_v8qi_int
    = build_function_type (integer_type_node,
                           tree_cons (NULL_TREE, V8QI_type_node,
                                      tree_cons (NULL_TREE, integer_type_node,
                                                 endlink)));
  tree int_ftype_v4hi_int
    = build_function_type (integer_type_node,
                           tree_cons (NULL_TREE, V4HI_type_node,
                                      tree_cons (NULL_TREE, integer_type_node,
                                                 endlink)));
  tree int_ftype_v2si_int
    = build_function_type (integer_type_node,
                           tree_cons (NULL_TREE, V2SI_type_node,
                                      tree_cons (NULL_TREE, integer_type_node,
                                                 endlink)));
  tree v8qi_ftype_v8qi_int_int
    = build_function_type (V8QI_type_node,
                           tree_cons (NULL_TREE, V8QI_type_node,
                                      tree_cons (NULL_TREE, integer_type_node,
                                                 tree_cons (NULL_TREE,
                                                            integer_type_node,
                                                            endlink))));
  tree v4hi_ftype_v4hi_int_int
    = build_function_type (V4HI_type_node,
                           tree_cons (NULL_TREE, V4HI_type_node,
                                      tree_cons (NULL_TREE, integer_type_node,
                                                 tree_cons (NULL_TREE,
                                                            integer_type_node,
                                                            endlink))));
  tree v2si_ftype_v2si_int_int
    = build_function_type (V2SI_type_node,
                           tree_cons (NULL_TREE, V2SI_type_node,
                                      tree_cons (NULL_TREE, integer_type_node,
                                                 tree_cons (NULL_TREE,
                                                            integer_type_node,
                                                            endlink))));
  /* Miscellaneous.  */
  tree v8qi_ftype_v4hi_v4hi
    = build_function_type (V8QI_type_node,
                           tree_cons (NULL_TREE, V4HI_type_node,
                                      tree_cons (NULL_TREE, V4HI_type_node,
                                                 endlink)));
  tree v4hi_ftype_v2si_v2si
    = build_function_type (V4HI_type_node,
                           tree_cons (NULL_TREE, V2SI_type_node,
                                      tree_cons (NULL_TREE, V2SI_type_node,
                                                 endlink)));
  tree v2si_ftype_v4hi_v4hi
    = build_function_type (V2SI_type_node,
                           tree_cons (NULL_TREE, V4HI_type_node,
                                      tree_cons (NULL_TREE, V4HI_type_node,
                                                 endlink)));
  tree v2si_ftype_v8qi_v8qi
    = build_function_type (V2SI_type_node,
                           tree_cons (NULL_TREE, V8QI_type_node,
                                      tree_cons (NULL_TREE, V8QI_type_node,
                                                 endlink)));
  tree v4hi_ftype_v4hi_di
    = build_function_type (V4HI_type_node,
                           tree_cons (NULL_TREE, V4HI_type_node,
                                      tree_cons (NULL_TREE,
                                                 long_long_integer_type_node,
                                                 endlink)));
  tree v2si_ftype_v2si_di
    = build_function_type (V2SI_type_node,
                           tree_cons (NULL_TREE, V2SI_type_node,
                                      tree_cons (NULL_TREE,
                                                 long_long_integer_type_node,
                                                 endlink)));
  tree void_ftype_int_int
    = build_function_type (void_type_node,
                           tree_cons (NULL_TREE, integer_type_node,
                                      tree_cons (NULL_TREE, integer_type_node,
                                                 endlink)));
  tree di_ftype_void
    = build_function_type (long_long_unsigned_type_node, endlink);
  tree di_ftype_v8qi
    = build_function_type (long_long_integer_type_node,
                           tree_cons (NULL_TREE, V8QI_type_node,
                                      endlink));
  tree di_ftype_v4hi
    = build_function_type (long_long_integer_type_node,
                           tree_cons (NULL_TREE, V4HI_type_node,
                                      endlink));
  tree di_ftype_v2si
    = build_function_type (long_long_integer_type_node,
                           tree_cons (NULL_TREE, V2SI_type_node,
                                      endlink));
  tree v2si_ftype_v4hi
    = build_function_type (V2SI_type_node,
                           tree_cons (NULL_TREE, V4HI_type_node,
                                      endlink));
  tree v4hi_ftype_v8qi
    = build_function_type (V4HI_type_node,
                           tree_cons (NULL_TREE, V8QI_type_node,
                                      endlink));

  tree di_ftype_di_v4hi_v4hi
    = build_function_type (long_long_unsigned_type_node,
                           tree_cons (NULL_TREE,
                                      long_long_unsigned_type_node,
                                      tree_cons (NULL_TREE, V4HI_type_node,
                                                 tree_cons (NULL_TREE,
                                                            V4HI_type_node,
                                                            endlink))));

  tree di_ftype_v4hi_v4hi
    = build_function_type (long_long_unsigned_type_node,
                           tree_cons (NULL_TREE, V4HI_type_node,
                                      tree_cons (NULL_TREE, V4HI_type_node,
                                                 endlink)));

  /* Normal vector binops.  */
  tree v8qi_ftype_v8qi_v8qi
    = build_function_type (V8QI_type_node,
                           tree_cons (NULL_TREE, V8QI_type_node,
                                      tree_cons (NULL_TREE, V8QI_type_node,
                                                 endlink)));
  tree v4hi_ftype_v4hi_v4hi
    = build_function_type (V4HI_type_node,
                           tree_cons (NULL_TREE, V4HI_type_node,
                                      tree_cons (NULL_TREE, V4HI_type_node,
                                                 endlink)));
  tree v2si_ftype_v2si_v2si
    = build_function_type (V2SI_type_node,
                           tree_cons (NULL_TREE, V2SI_type_node,
                                      tree_cons (NULL_TREE, V2SI_type_node,
                                                 endlink)));
  tree di_ftype_di_di
    = build_function_type (long_long_unsigned_type_node,
                           tree_cons (NULL_TREE, long_long_unsigned_type_node,
                                      tree_cons (NULL_TREE,
                                                 long_long_unsigned_type_node,
                                                 endlink)));

  /* Add all builtins that are more or less simple operations on two
     operands.  */
  for (i = 0, d = bdesc_2arg; i < ARRAY_SIZE (bdesc_2arg); i++, d++)
    {
      /* Use one of the operands; the target can have a different mode for
         mask-generating compares.  */
      enum machine_mode mode;
      tree type;

      if (d->name == 0)
        continue;

      mode = insn_data[d->icode].operand[1].mode;

      switch (mode)
        {
        case V8QImode:
          type = v8qi_ftype_v8qi_v8qi;
          break;
        case V4HImode:
          type = v4hi_ftype_v4hi_v4hi;
          break;
        case V2SImode:
          type = v2si_ftype_v2si_v2si;
          break;
        case DImode:
          type = di_ftype_di_di;
          break;

        default:
          abort ();
        }

      def_mbuiltin (d->mask, d->name, type, d->code);
    }

  /* Add the remaining MMX insns with somewhat more complicated types.  */
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wzero", di_ftype_void, ARM_BUILTIN_WZERO);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_setwcx", void_ftype_int_int, ARM_BUILTIN_SETWCX);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_getwcx", int_ftype_int, ARM_BUILTIN_GETWCX);

  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsllh", v4hi_ftype_v4hi_di, ARM_BUILTIN_WSLLH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsllw", v2si_ftype_v2si_di, ARM_BUILTIN_WSLLW);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wslld", di_ftype_di_di, ARM_BUILTIN_WSLLD);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsllhi", v4hi_ftype_v4hi_int, ARM_BUILTIN_WSLLHI);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsllwi", v2si_ftype_v2si_int, ARM_BUILTIN_WSLLWI);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wslldi", di_ftype_di_int, ARM_BUILTIN_WSLLDI);

  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsrlh", v4hi_ftype_v4hi_di, ARM_BUILTIN_WSRLH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsrlw", v2si_ftype_v2si_di, ARM_BUILTIN_WSRLW);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsrld", di_ftype_di_di, ARM_BUILTIN_WSRLD);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsrlhi", v4hi_ftype_v4hi_int, ARM_BUILTIN_WSRLHI);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsrlwi", v2si_ftype_v2si_int, ARM_BUILTIN_WSRLWI);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsrldi", di_ftype_di_int, ARM_BUILTIN_WSRLDI);

  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsrah", v4hi_ftype_v4hi_di, ARM_BUILTIN_WSRAH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsraw", v2si_ftype_v2si_di, ARM_BUILTIN_WSRAW);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsrad", di_ftype_di_di, ARM_BUILTIN_WSRAD);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsrahi", v4hi_ftype_v4hi_int, ARM_BUILTIN_WSRAHI);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsrawi", v2si_ftype_v2si_int, ARM_BUILTIN_WSRAWI);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsradi", di_ftype_di_int, ARM_BUILTIN_WSRADI);

  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wrorh", v4hi_ftype_v4hi_di, ARM_BUILTIN_WRORH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wrorw", v2si_ftype_v2si_di, ARM_BUILTIN_WRORW);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wrord", di_ftype_di_di, ARM_BUILTIN_WRORD);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wrorhi", v4hi_ftype_v4hi_int, ARM_BUILTIN_WRORHI);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wrorwi", v2si_ftype_v2si_int, ARM_BUILTIN_WRORWI);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wrordi", di_ftype_di_int, ARM_BUILTIN_WRORDI);

  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wshufh", v4hi_ftype_v4hi_int, ARM_BUILTIN_WSHUFH);

  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsadb", v2si_ftype_v8qi_v8qi, ARM_BUILTIN_WSADB);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsadh", v2si_ftype_v4hi_v4hi, ARM_BUILTIN_WSADH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsadbz", v2si_ftype_v8qi_v8qi, ARM_BUILTIN_WSADBZ);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wsadhz", v2si_ftype_v4hi_v4hi, ARM_BUILTIN_WSADHZ);

  def_mbuiltin (FL_IWMMXT, "__builtin_arm_textrmsb", int_ftype_v8qi_int, ARM_BUILTIN_TEXTRMSB);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_textrmsh", int_ftype_v4hi_int, ARM_BUILTIN_TEXTRMSH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_textrmsw", int_ftype_v2si_int, ARM_BUILTIN_TEXTRMSW);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_textrmub", int_ftype_v8qi_int, ARM_BUILTIN_TEXTRMUB);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_textrmuh", int_ftype_v4hi_int, ARM_BUILTIN_TEXTRMUH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_textrmuw", int_ftype_v2si_int, ARM_BUILTIN_TEXTRMUW);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_tinsrb", v8qi_ftype_v8qi_int_int, ARM_BUILTIN_TINSRB);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_tinsrh", v4hi_ftype_v4hi_int_int, ARM_BUILTIN_TINSRH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_tinsrw", v2si_ftype_v2si_int_int, ARM_BUILTIN_TINSRW);

  def_mbuiltin (FL_IWMMXT, "__builtin_arm_waccb", di_ftype_v8qi, ARM_BUILTIN_WACCB);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wacch", di_ftype_v4hi, ARM_BUILTIN_WACCH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_waccw", di_ftype_v2si, ARM_BUILTIN_WACCW);

  def_mbuiltin (FL_IWMMXT, "__builtin_arm_tmovmskb", int_ftype_v8qi, ARM_BUILTIN_TMOVMSKB);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_tmovmskh", int_ftype_v4hi, ARM_BUILTIN_TMOVMSKH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_tmovmskw", int_ftype_v2si, ARM_BUILTIN_TMOVMSKW);

  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wpackhss", v8qi_ftype_v4hi_v4hi, ARM_BUILTIN_WPACKHSS);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wpackhus", v8qi_ftype_v4hi_v4hi, ARM_BUILTIN_WPACKHUS);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wpackwus", v4hi_ftype_v2si_v2si, ARM_BUILTIN_WPACKWUS);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wpackwss", v4hi_ftype_v2si_v2si, ARM_BUILTIN_WPACKWSS);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wpackdus", v2si_ftype_di_di, ARM_BUILTIN_WPACKDUS);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wpackdss", v2si_ftype_di_di, ARM_BUILTIN_WPACKDSS);

  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wunpckehub", v4hi_ftype_v8qi, ARM_BUILTIN_WUNPCKEHUB);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wunpckehuh", v2si_ftype_v4hi, ARM_BUILTIN_WUNPCKEHUH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wunpckehuw", di_ftype_v2si, ARM_BUILTIN_WUNPCKEHUW);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wunpckehsb", v4hi_ftype_v8qi, ARM_BUILTIN_WUNPCKEHSB);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wunpckehsh", v2si_ftype_v4hi, ARM_BUILTIN_WUNPCKEHSH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wunpckehsw", di_ftype_v2si, ARM_BUILTIN_WUNPCKEHSW);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wunpckelub", v4hi_ftype_v8qi, ARM_BUILTIN_WUNPCKELUB);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wunpckeluh", v2si_ftype_v4hi, ARM_BUILTIN_WUNPCKELUH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wunpckeluw", di_ftype_v2si, ARM_BUILTIN_WUNPCKELUW);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wunpckelsb", v4hi_ftype_v8qi, ARM_BUILTIN_WUNPCKELSB);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wunpckelsh", v2si_ftype_v4hi, ARM_BUILTIN_WUNPCKELSH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wunpckelsw", di_ftype_v2si, ARM_BUILTIN_WUNPCKELSW);

  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wmacs", di_ftype_di_v4hi_v4hi, ARM_BUILTIN_WMACS);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wmacsz", di_ftype_v4hi_v4hi, ARM_BUILTIN_WMACSZ);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wmacu", di_ftype_di_v4hi_v4hi, ARM_BUILTIN_WMACU);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_wmacuz", di_ftype_v4hi_v4hi, ARM_BUILTIN_WMACUZ);

  def_mbuiltin (FL_IWMMXT, "__builtin_arm_walign", v8qi_ftype_v8qi_v8qi_int, ARM_BUILTIN_WALIGN);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_tmia", di_ftype_di_int_int, ARM_BUILTIN_TMIA);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_tmiaph", di_ftype_di_int_int, ARM_BUILTIN_TMIAPH);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_tmiabb", di_ftype_di_int_int, ARM_BUILTIN_TMIABB);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_tmiabt", di_ftype_di_int_int, ARM_BUILTIN_TMIABT);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_tmiatb", di_ftype_di_int_int, ARM_BUILTIN_TMIATB);
  def_mbuiltin (FL_IWMMXT, "__builtin_arm_tmiatt", di_ftype_di_int_int, ARM_BUILTIN_TMIATT);
}

static void
arm_init_builtins (void)
{
  if (TARGET_REALLY_IWMMXT)
    arm_init_iwmmxt_builtins ();
}

/* Errors in the source file can cause expand_expr to return const0_rtx
   where we expect a vector.  To avoid crashing, use one of the vector
   clear instructions.  */

static rtx
safe_vector_operand (rtx x, enum machine_mode mode)
{
  if (x != const0_rtx)
    return x;
  x = gen_reg_rtx (mode);

  emit_insn (gen_iwmmxt_clrdi (mode == DImode ? x
                               : gen_rtx_SUBREG (DImode, x, 0)));
  return x;
}

/* Subroutine of arm_expand_builtin to take care of binop insns.  */

static rtx
arm_expand_binop_builtin (enum insn_code icode,
                          tree arglist, rtx target)
{
  rtx pat;
  tree arg0 = TREE_VALUE (arglist);
  tree arg1 = TREE_VALUE (TREE_CHAIN (arglist));
  rtx op0 = expand_expr (arg0, NULL_RTX, VOIDmode, 0);
  rtx op1 = expand_expr (arg1, NULL_RTX, VOIDmode, 0);
  enum machine_mode tmode = insn_data[icode].operand[0].mode;
  enum machine_mode mode0 = insn_data[icode].operand[1].mode;
  enum machine_mode mode1 = insn_data[icode].operand[2].mode;

  if (VECTOR_MODE_P (mode0))
    op0 = safe_vector_operand (op0, mode0);
  if (VECTOR_MODE_P (mode1))
    op1 = safe_vector_operand (op1, mode1);

  if (! target
      || GET_MODE (target) != tmode
      || ! (*insn_data[icode].operand[0].predicate) (target, tmode))
    target = gen_reg_rtx (tmode);

  /* In case the insn wants input operands in modes different from
     the result, abort.  */
  if (GET_MODE (op0) != mode0 || GET_MODE (op1) != mode1)
    abort ();

  if (! (*insn_data[icode].operand[1].predicate) (op0, mode0))
    op0 = copy_to_mode_reg (mode0, op0);
  if (! (*insn_data[icode].operand[2].predicate) (op1, mode1))
    op1 = copy_to_mode_reg (mode1, op1);

  pat = GEN_FCN (icode) (target, op0, op1);
  if (! pat)
    return 0;
  emit_insn (pat);
  return target;
}

/* Subroutine of arm_expand_builtin to take care of unop insns.  */

static rtx
arm_expand_unop_builtin (enum insn_code icode,
                         tree arglist, rtx target, int do_load)
{
  rtx pat;
  tree arg0 = TREE_VALUE (arglist);
  rtx op0 = expand_expr (arg0, NULL_RTX, VOIDmode, 0);
  enum machine_mode tmode = insn_data[icode].operand[0].mode;
  enum machine_mode mode0 = insn_data[icode].operand[1].mode;

  if (! target
      || GET_MODE (target) != tmode
      || ! (*insn_data[icode].operand[0].predicate) (target, tmode))
    target = gen_reg_rtx (tmode);
  if (do_load)
    op0 = gen_rtx_MEM (mode0, copy_to_mode_reg (Pmode, op0));
  else
    {
      if (VECTOR_MODE_P (mode0))
        op0 = safe_vector_operand (op0, mode0);

      if (! (*insn_data[icode].operand[1].predicate) (op0, mode0))
        op0 = copy_to_mode_reg (mode0, op0);
    }

  pat = GEN_FCN (icode) (target, op0);
  if (! pat)
    return 0;
  emit_insn (pat);
  return target;
}

/* Expand an expression EXP that calls a built-in function,
   with result going to TARGET if that's convenient
   (and in mode MODE if that's convenient).
   SUBTARGET may be used as the target for computing one of EXP's operands.
   IGNORE is nonzero if the value is to be ignored.  */

static rtx
arm_expand_builtin (tree exp,
                    rtx target,
                    rtx subtarget ATTRIBUTE_UNUSED,
                    enum machine_mode mode ATTRIBUTE_UNUSED,
                    int ignore ATTRIBUTE_UNUSED)
{
  const struct builtin_description * d;
  enum insn_code    icode;
  tree              fndecl = TREE_OPERAND (TREE_OPERAND (exp, 0), 0);
  tree              arglist = TREE_OPERAND (exp, 1);
  tree              arg0;
  tree              arg1;
  tree              arg2;
  rtx               op0;
  rtx               op1;
  rtx               op2;
  rtx               pat;
  int               fcode = DECL_FUNCTION_CODE (fndecl);
  size_t            i;
  enum machine_mode tmode;
  enum machine_mode mode0;
  enum machine_mode mode1;
  enum machine_mode mode2;

  switch (fcode)
    {
    case ARM_BUILTIN_TEXTRMSB:
    case ARM_BUILTIN_TEXTRMUB:
    case ARM_BUILTIN_TEXTRMSH:
    case ARM_BUILTIN_TEXTRMUH:
    case ARM_BUILTIN_TEXTRMSW:
    case ARM_BUILTIN_TEXTRMUW:
      icode = (fcode == ARM_BUILTIN_TEXTRMSB ? CODE_FOR_iwmmxt_textrmsb
               : fcode == ARM_BUILTIN_TEXTRMUB ? CODE_FOR_iwmmxt_textrmub
               : fcode == ARM_BUILTIN_TEXTRMSH ? CODE_FOR_iwmmxt_textrmsh
               : fcode == ARM_BUILTIN_TEXTRMUH ? CODE_FOR_iwmmxt_textrmuh
               : CODE_FOR_iwmmxt_textrmw);

      arg0 = TREE_VALUE (arglist);
      arg1 = TREE_VALUE (TREE_CHAIN (arglist));
      op0 = expand_expr (arg0, NULL_RTX, VOIDmode, 0);
      op1 = expand_expr (arg1, NULL_RTX, VOIDmode, 0);
      tmode = insn_data[icode].operand[0].mode;
      mode0 = insn_data[icode].operand[1].mode;
      mode1 = insn_data[icode].operand[2].mode;

      if (! (*insn_data[icode].operand[1].predicate) (op0, mode0))
        op0 = copy_to_mode_reg (mode0, op0);
      if (! (*insn_data[icode].operand[2].predicate) (op1, mode1))
        {
          /* @@@ better error message */
          error ("selector must be an immediate");
          return gen_reg_rtx (tmode);
        }
      if (target == 0
          || GET_MODE (target) != tmode
          || ! (*insn_data[icode].operand[0].predicate) (target, tmode))
        target = gen_reg_rtx (tmode);
      pat = GEN_FCN (icode) (target, op0, op1);
      if (! pat)
        return 0;
      emit_insn (pat);
      return target;

    case ARM_BUILTIN_TINSRB:
    case ARM_BUILTIN_TINSRH:
    case ARM_BUILTIN_TINSRW:
      icode = (fcode == ARM_BUILTIN_TINSRB ? CODE_FOR_iwmmxt_tinsrb
               : fcode == ARM_BUILTIN_TINSRH ? CODE_FOR_iwmmxt_tinsrh
               : CODE_FOR_iwmmxt_tinsrw);
      arg0 = TREE_VALUE (arglist);
      arg1 = TREE_VALUE (TREE_CHAIN (arglist));
      arg2 = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (arglist)));
      op0 = expand_expr (arg0, NULL_RTX, VOIDmode, 0);
      op1 = expand_expr (arg1, NULL_RTX, VOIDmode, 0);
      op2 = expand_expr (arg2, NULL_RTX, VOIDmode, 0);
      tmode = insn_data[icode].operand[0].mode;
      mode0 = insn_data[icode].operand[1].mode;
      mode1 = insn_data[icode].operand[2].mode;
      mode2 = insn_data[icode].operand[3].mode;

      if (! (*insn_data[icode].operand[1].predicate) (op0, mode0))
        op0 = copy_to_mode_reg (mode0, op0);
      if (! (*insn_data[icode].operand[2].predicate) (op1, mode1))
        op1 = copy_to_mode_reg (mode1, op1);
      if (! (*insn_data[icode].operand[3].predicate) (op2, mode2))
        {
          /* @@@ better error message */
          error ("selector must be an immediate");
          return const0_rtx;
        }
      if (target == 0
          || GET_MODE (target) != tmode
          || ! (*insn_data[icode].operand[0].predicate) (target, tmode))
        target = gen_reg_rtx (tmode);
      pat = GEN_FCN (icode) (target, op0, op1, op2);
      if (! pat)
        return 0;
      emit_insn (pat);
      return target;

    case ARM_BUILTIN_SETWCX:
      arg0 = TREE_VALUE (arglist);
      arg1 = TREE_VALUE (TREE_CHAIN (arglist));
      op0 = force_reg (SImode, expand_expr (arg0, NULL_RTX, VOIDmode, 0));
      op1 = expand_expr (arg1, NULL_RTX, VOIDmode, 0);
      emit_insn (gen_iwmmxt_tmcr (op1, op0));
      return 0;

    case ARM_BUILTIN_GETWCX:
      arg0 = TREE_VALUE (arglist);
      op0 = expand_expr (arg0, NULL_RTX, VOIDmode, 0);
      target = gen_reg_rtx (SImode);
      emit_insn (gen_iwmmxt_tmrc (target, op0));
      return target;

    case ARM_BUILTIN_WSHUFH:
      icode = CODE_FOR_iwmmxt_wshufh;
      arg0 = TREE_VALUE (arglist);
      arg1 = TREE_VALUE (TREE_CHAIN (arglist));
      op0 = expand_expr (arg0, NULL_RTX, VOIDmode, 0);
      op1 = expand_expr (arg1, NULL_RTX, VOIDmode, 0);
      tmode = insn_data[icode].operand[0].mode;
      mode1 = insn_data[icode].operand[1].mode;
      mode2 = insn_data[icode].operand[2].mode;

      if (! (*insn_data[icode].operand[1].predicate) (op0, mode1))
        op0 = copy_to_mode_reg (mode1, op0);
      if (! (*insn_data[icode].operand[2].predicate) (op1, mode2))
        {
          /* @@@ better error message */
          error ("mask must be an immediate");
          return const0_rtx;
        }
      if (target == 0
          || GET_MODE (target) != tmode
          || ! (*insn_data[icode].operand[0].predicate) (target, tmode))
        target = gen_reg_rtx (tmode);
      pat = GEN_FCN (icode) (target, op0, op1);
      if (! pat)
        return 0;
      emit_insn (pat);
      return target;

    case ARM_BUILTIN_WSADB:
      return arm_expand_binop_builtin (CODE_FOR_iwmmxt_wsadb, arglist, target);
    case ARM_BUILTIN_WSADH:
      return arm_expand_binop_builtin (CODE_FOR_iwmmxt_wsadh, arglist, target);
    case ARM_BUILTIN_WSADBZ:
      return arm_expand_binop_builtin (CODE_FOR_iwmmxt_wsadbz, arglist, target);
    case ARM_BUILTIN_WSADHZ:
      return arm_expand_binop_builtin (CODE_FOR_iwmmxt_wsadhz, arglist, target);

      /* Several three-argument builtins.  */
    case ARM_BUILTIN_WMACS:
    case ARM_BUILTIN_WMACU:
    case ARM_BUILTIN_WALIGN:
    case ARM_BUILTIN_TMIA:
    case ARM_BUILTIN_TMIAPH:
    case ARM_BUILTIN_TMIATT:
    case ARM_BUILTIN_TMIATB:
    case ARM_BUILTIN_TMIABT:
    case ARM_BUILTIN_TMIABB:
      icode = (fcode == ARM_BUILTIN_WMACS ? CODE_FOR_iwmmxt_wmacs
               : fcode == ARM_BUILTIN_WMACU ? CODE_FOR_iwmmxt_wmacu
               : fcode == ARM_BUILTIN_TMIA ? CODE_FOR_iwmmxt_tmia
               : fcode == ARM_BUILTIN_TMIAPH ? CODE_FOR_iwmmxt_tmiaph
               : fcode == ARM_BUILTIN_TMIABB ? CODE_FOR_iwmmxt_tmiabb
               : fcode == ARM_BUILTIN_TMIABT ? CODE_FOR_iwmmxt_tmiabt
               : fcode == ARM_BUILTIN_TMIATB ? CODE_FOR_iwmmxt_tmiatb
               : fcode == ARM_BUILTIN_TMIATT ? CODE_FOR_iwmmxt_tmiatt
               : CODE_FOR_iwmmxt_walign);
      arg0 = TREE_VALUE (arglist);
      arg1 = TREE_VALUE (TREE_CHAIN (arglist));
      arg2 = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (arglist)));
      op0 = expand_expr (arg0, NULL_RTX, VOIDmode, 0);
      op1 = expand_expr (arg1, NULL_RTX, VOIDmode, 0);
      op2 = expand_expr (arg2, NULL_RTX, VOIDmode, 0);
      tmode = insn_data[icode].operand[0].mode;
      mode0 = insn_data[icode].operand[1].mode;
      mode1 = insn_data[icode].operand[2].mode;
      mode2 = insn_data[icode].operand[3].mode;

      if (! (*insn_data[icode].operand[1].predicate) (op0, mode0))
        op0 = copy_to_mode_reg (mode0, op0);
      if (! (*insn_data[icode].operand[2].predicate) (op1, mode1))
        op1 = copy_to_mode_reg (mode1, op1);
      if (! (*insn_data[icode].operand[3].predicate) (op2, mode2))
        op2 = copy_to_mode_reg (mode2, op2);
      if (target == 0
          || GET_MODE (target) != tmode
          || ! (*insn_data[icode].operand[0].predicate) (target, tmode))
        target = gen_reg_rtx (tmode);
      pat = GEN_FCN (icode) (target, op0, op1, op2);
      if (! pat)
        return 0;
      emit_insn (pat);
      return target;

    case ARM_BUILTIN_WZERO:
      target = gen_reg_rtx (DImode);
      emit_insn (gen_iwmmxt_clrdi (target));
      return target;

    default:
      break;
    }

  for (i = 0, d = bdesc_2arg; i < ARRAY_SIZE (bdesc_2arg); i++, d++)
    if (d->code == (const enum arm_builtins) fcode)
      return arm_expand_binop_builtin (d->icode, arglist, target);

  for (i = 0, d = bdesc_1arg; i < ARRAY_SIZE (bdesc_1arg); i++, d++)
    if (d->code == (const enum arm_builtins) fcode)
      return arm_expand_unop_builtin (d->icode, arglist, target, 0);

  /* @@@ Should really do something sensible here.  */
  return NULL_RTX;
}
\f
/* Return the number (counting from 0) of
   the least significant set bit in MASK.  */

inline static int
number_of_first_bit_set (unsigned mask)
{
  int bit;

  for (bit = 0;
       (mask & (1 << bit)) == 0;
       ++bit)
    continue;

  return bit;
}

/* Emit code to push or pop registers to or from the stack.  F is the
   assembly file.  MASK is the registers to push or pop.  PUSH is
   nonzero if we should push, and zero if we should pop.  For debugging
   output, if pushing, adjust CFA_OFFSET by the amount of space added
   to the stack.  REAL_REGS should have the same number of bits set as
   MASK, and will be used instead (in the same order) to describe which
   registers were saved - this is used to mark the save slots when we
   push high registers after moving them to low registers.  */
static void
thumb_pushpop (FILE *f, unsigned long mask, int push, int *cfa_offset,
               unsigned long real_regs)
{
  int regno;
  int lo_mask = mask & 0xFF;
  int pushed_words = 0;

  if (mask == 0)
    abort ();

  if (lo_mask == 0 && !push && (mask & (1 << PC_REGNUM)))
    {
      /* Special case.  Do not generate a POP PC statement here, do it in
         thumb_exit() */
      thumb_exit (f, -1);
      return;
    }

  fprintf (f, "\t%s\t{", push ? "push" : "pop");

  /* Look at the low registers first.  */
  for (regno = 0; regno <= LAST_LO_REGNUM; regno++, lo_mask >>= 1)
    {
      if (lo_mask & 1)
        {
          asm_fprintf (f, "%r", regno);

          if ((lo_mask & ~1) != 0)
            fprintf (f, ", ");

          pushed_words++;
        }
    }

  if (push && (mask & (1 << LR_REGNUM)))
    {
      /* Catch pushing the LR.  */
      if (mask & 0xFF)
        fprintf (f, ", ");

      asm_fprintf (f, "%r", LR_REGNUM);

      pushed_words++;
    }
  else if (!push && (mask & (1 << PC_REGNUM)))
    {
      /* Catch popping the PC.  */
      if (TARGET_INTERWORK || TARGET_BACKTRACE
          || current_function_calls_eh_return)
        {
          /* The PC is never poped directly, instead
             it is popped into r3 and then BX is used.  */
          fprintf (f, "}\n");

          thumb_exit (f, -1);

          return;
        }
      else
        {
          if (mask & 0xFF)
            fprintf (f, ", ");

          asm_fprintf (f, "%r", PC_REGNUM);
        }
    }

  fprintf (f, "}\n");

  if (push && pushed_words && dwarf2out_do_frame ())
    {
      char *l = dwarf2out_cfi_label ();
      int pushed_mask = real_regs;

      *cfa_offset += pushed_words * 4;
      dwarf2out_def_cfa (l, SP_REGNUM, *cfa_offset);

      pushed_words = 0;
      pushed_mask = real_regs;
      for (regno = 0; regno <= 14; regno++, pushed_mask >>= 1)
        {
          if (pushed_mask & 1)
            dwarf2out_reg_save (l, regno, 4 * pushed_words++ - *cfa_offset);
        }
    }
}

/* Generate code to return from a thumb function.
   If 'reg_containing_return_addr' is -1, then the return address is
   actually on the stack, at the stack pointer.  */
static void
thumb_exit (FILE *f, int reg_containing_return_addr)
{
  unsigned regs_available_for_popping;
  unsigned regs_to_pop;
  int pops_needed;
  unsigned available;
  unsigned required;
  int mode;
  int size;
  int restore_a4 = FALSE;

  /* Compute the registers we need to pop.  */
  regs_to_pop = 0;
  pops_needed = 0;

  if (reg_containing_return_addr == -1)
    {
      regs_to_pop |= 1 << LR_REGNUM;
      ++pops_needed;
    }

  if (TARGET_BACKTRACE)
    {
      /* Restore the (ARM) frame pointer and stack pointer.  */
      regs_to_pop |= (1 << ARM_HARD_FRAME_POINTER_REGNUM) | (1 << SP_REGNUM);
      pops_needed += 2;
    }

  /* If there is nothing to pop then just emit the BX instruction and
     return.  */
  if (pops_needed == 0)
    {
      if (current_function_calls_eh_return)
        asm_fprintf (f, "\tadd\t%r, %r\n", SP_REGNUM, ARM_EH_STACKADJ_REGNUM);

      asm_fprintf (f, "\tbx\t%r\n", reg_containing_return_addr);
      return;
    }
  /* Otherwise if we are not supporting interworking and we have not created
     a backtrace structure and the function was not entered in ARM mode then
     just pop the return address straight into the PC.  */
  else if (!TARGET_INTERWORK
           && !TARGET_BACKTRACE
           && !is_called_in_ARM_mode (current_function_decl)
           && !current_function_calls_eh_return)
    {
      asm_fprintf (f, "\tpop\t{%r}\n", PC_REGNUM);
      return;
    }

  /* Find out how many of the (return) argument registers we can corrupt.  */
  regs_available_for_popping = 0;

  /* If returning via __builtin_eh_return, the bottom three registers
     all contain information needed for the return.  */
  if (current_function_calls_eh_return)
    size = 12;
  else
    {
      /* If we can deduce the registers used from the function's
         return value.  This is more reliable that examining
         regs_ever_live[] because that will be set if the register is
         ever used in the function, not just if the register is used
         to hold a return value.  */

      if (current_function_return_rtx != 0)
        mode = GET_MODE (current_function_return_rtx);
      else
        mode = DECL_MODE (DECL_RESULT (current_function_decl));

      size = GET_MODE_SIZE (mode);

      if (size == 0)
        {
          /* In a void function we can use any argument register.
             In a function that returns a structure on the stack
             we can use the second and third argument registers.  */
          if (mode == VOIDmode)
            regs_available_for_popping =
              (1 << ARG_REGISTER (1))
              | (1 << ARG_REGISTER (2))
              | (1 << ARG_REGISTER (3));
          else
            regs_available_for_popping =
              (1 << ARG_REGISTER (2))
              | (1 << ARG_REGISTER (3));
        }
      else if (size <= 4)
        regs_available_for_popping =
          (1 << ARG_REGISTER (2))
          | (1 << ARG_REGISTER (3));
      else if (size <= 8)
        regs_available_for_popping =
          (1 << ARG_REGISTER (3));
    }

  /* Match registers to be popped with registers into which we pop them.  */
  for (available = regs_available_for_popping,
       required  = regs_to_pop;
       required != 0 && available != 0;
       available &= ~(available & - available),
       required  &= ~(required  & - required))
    -- pops_needed;

  /* If we have any popping registers left over, remove them.  */
  if (available > 0)
    regs_available_for_popping &= ~available;

  /* Otherwise if we need another popping register we can use
     the fourth argument register.  */
  else if (pops_needed)
    {
      /* If we have not found any free argument registers and
         reg a4 contains the return address, we must move it.  */
      if (regs_available_for_popping == 0
          && reg_containing_return_addr == LAST_ARG_REGNUM)
        {
          asm_fprintf (f, "\tmov\t%r, %r\n", LR_REGNUM, LAST_ARG_REGNUM);
          reg_containing_return_addr = LR_REGNUM;
        }
      else if (size > 12)
        {
          /* Register a4 is being used to hold part of the return value,
             but we have dire need of a free, low register.  */
          restore_a4 = TRUE;

          asm_fprintf (f, "\tmov\t%r, %r\n",IP_REGNUM, LAST_ARG_REGNUM);
        }

      if (reg_containing_return_addr != LAST_ARG_REGNUM)
        {
          /* The fourth argument register is available.  */
          regs_available_for_popping |= 1 << LAST_ARG_REGNUM;

          --pops_needed;
        }
    }

  /* Pop as many registers as we can.  */
  thumb_pushpop (f, regs_available_for_popping, FALSE, NULL,
                 regs_available_for_popping);

  /* Process the registers we popped.  */
  if (reg_containing_return_addr == -1)
    {
      /* The return address was popped into the lowest numbered register.  */
      regs_to_pop &= ~(1 << LR_REGNUM);

      reg_containing_return_addr =
        number_of_first_bit_set (regs_available_for_popping);

      /* Remove this register for the mask of available registers, so that
         the return address will not be corrupted by further pops.  */
      regs_available_for_popping &= ~(1 << reg_containing_return_addr);
    }

  /* If we popped other registers then handle them here.  */
  if (regs_available_for_popping)
    {
      int frame_pointer;

      /* Work out which register currently contains the frame pointer.  */
      frame_pointer = number_of_first_bit_set (regs_available_for_popping);

      /* Move it into the correct place.  */
      asm_fprintf (f, "\tmov\t%r, %r\n",
                   ARM_HARD_FRAME_POINTER_REGNUM, frame_pointer);

      /* (Temporarily) remove it from the mask of popped registers.  */
      regs_available_for_popping &= ~(1 << frame_pointer);
      regs_to_pop &= ~(1 << ARM_HARD_FRAME_POINTER_REGNUM);

      if (regs_available_for_popping)
        {
          int stack_pointer;

          /* We popped the stack pointer as well,
             find the register that contains it.  */
          stack_pointer = number_of_first_bit_set (regs_available_for_popping);

          /* Move it into the stack register.  */
          asm_fprintf (f, "\tmov\t%r, %r\n", SP_REGNUM, stack_pointer);

          /* At this point we have popped all necessary registers, so
             do not worry about restoring regs_available_for_popping
             to its correct value:

             assert (pops_needed == 0)
             assert (regs_available_for_popping == (1 << frame_pointer))
             assert (regs_to_pop == (1 << STACK_POINTER))  */
        }
      else
        {
          /* Since we have just move the popped value into the frame
             pointer, the popping register is available for reuse, and
             we know that we still have the stack pointer left to pop.  */
          regs_available_for_popping |= (1 << frame_pointer);
        }
    }

  /* If we still have registers left on the stack, but we no longer have
     any registers into which we can pop them, then we must move the return
     address into the link register and make available the register that
     contained it.  */
  if (regs_available_for_popping == 0 && pops_needed > 0)
    {
      regs_available_for_popping |= 1 << reg_containing_return_addr;

      asm_fprintf (f, "\tmov\t%r, %r\n", LR_REGNUM,
                   reg_containing_return_addr);

      reg_containing_return_addr = LR_REGNUM;
    }

  /* If we have registers left on the stack then pop some more.
     We know that at most we will want to pop FP and SP.  */
  if (pops_needed > 0)
    {
      int  popped_into;
      int  move_to;

      thumb_pushpop (f, regs_available_for_popping, FALSE, NULL,
                     regs_available_for_popping);

      /* We have popped either FP or SP.
         Move whichever one it is into the correct register.  */
      popped_into = number_of_first_bit_set (regs_available_for_popping);
      move_to     = number_of_first_bit_set (regs_to_pop);

      asm_fprintf (f, "\tmov\t%r, %r\n", move_to, popped_into);

      regs_to_pop &= ~(1 << move_to);

      --pops_needed;
    }

  /* If we still have not popped everything then we must have only
     had one register available to us and we are now popping the SP.  */
  if (pops_needed > 0)
    {
      int  popped_into;

      thumb_pushpop (f, regs_available_for_popping, FALSE, NULL,
                     regs_available_for_popping);

      popped_into = number_of_first_bit_set (regs_available_for_popping);

      asm_fprintf (f, "\tmov\t%r, %r\n", SP_REGNUM, popped_into);
      /*
        assert (regs_to_pop == (1 << STACK_POINTER))
        assert (pops_needed == 1)
      */
    }

  /* If necessary restore the a4 register.  */
  if (restore_a4)
    {
      if (reg_containing_return_addr != LR_REGNUM)
        {
          asm_fprintf (f, "\tmov\t%r, %r\n", LR_REGNUM, LAST_ARG_REGNUM);
          reg_containing_return_addr = LR_REGNUM;
        }

      asm_fprintf (f, "\tmov\t%r, %r\n", LAST_ARG_REGNUM, IP_REGNUM);
    }

  if (current_function_calls_eh_return)
    asm_fprintf (f, "\tadd\t%r, %r\n", SP_REGNUM, ARM_EH_STACKADJ_REGNUM);

  /* Return to caller.  */
  asm_fprintf (f, "\tbx\t%r\n", reg_containing_return_addr);
}

\f
void
thumb_final_prescan_insn (rtx insn)
{
  if (flag_print_asm_name)
    asm_fprintf (asm_out_file, "%@ 0x%04x\n",
                 INSN_ADDRESSES (INSN_UID (insn)));
}

int
thumb_shiftable_const (unsigned HOST_WIDE_INT val)
{
  unsigned HOST_WIDE_INT mask = 0xff;
  int i;

  if (val == 0) /* XXX */
    return 0;

  for (i = 0; i < 25; i++)
    if ((val & (mask << i)) == val)
      return 1;

  return 0;
}

/* Returns nonzero if the current function contains,
   or might contain a far jump.  */
static int
thumb_far_jump_used_p (void)
{
  rtx insn;

  /* This test is only important for leaf functions.  */
  /* assert (!leaf_function_p ()); */

  /* If we have already decided that far jumps may be used,
     do not bother checking again, and always return true even if
     it turns out that they are not being used.  Once we have made
     the decision that far jumps are present (and that hence the link
     register will be pushed onto the stack) we cannot go back on it.  */
  if (cfun->machine->far_jump_used)
    return 1;

  /* If this function is not being called from the prologue/epilogue
     generation code then it must be being called from the
     INITIAL_ELIMINATION_OFFSET macro.  */
  if (!(ARM_DOUBLEWORD_ALIGN || reload_completed))
    {
      /* In this case we know that we are being asked about the elimination
         of the arg pointer register.  If that register is not being used,
         then there are no arguments on the stack, and we do not have to
         worry that a far jump might force the prologue to push the link
         register, changing the stack offsets.  In this case we can just
         return false, since the presence of far jumps in the function will
         not affect stack offsets.

         If the arg pointer is live (or if it was live, but has now been
         eliminated and so set to dead) then we do have to test to see if
         the function might contain a far jump.  This test can lead to some
         false negatives, since before reload is completed, then length of
         branch instructions is not known, so gcc defaults to returning their
         longest length, which in turn sets the far jump attribute to true.

         A false negative will not result in bad code being generated, but it
         will result in a needless push and pop of the link register.  We
         hope that this does not occur too often.

         If we need doubleword stack alignment this could affect the other
         elimination offsets so we can't risk getting it wrong.  */
      if (regs_ever_live [ARG_POINTER_REGNUM])
        cfun->machine->arg_pointer_live = 1;
      else if (!cfun->machine->arg_pointer_live)
        return 0;
    }

  /* Check to see if the function contains a branch
     insn with the far jump attribute set.  */
  for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
    {
      if (GET_CODE (insn) == JUMP_INSN
          /* Ignore tablejump patterns.  */
          && GET_CODE (PATTERN (insn)) != ADDR_VEC
          && GET_CODE (PATTERN (insn)) != ADDR_DIFF_VEC
          && get_attr_far_jump (insn) == FAR_JUMP_YES
          )
        {
          /* Record the fact that we have decided that
             the function does use far jumps.  */
          cfun->machine->far_jump_used = 1;
          return 1;
        }
    }

  return 0;
}

/* Return nonzero if FUNC must be entered in ARM mode.  */
int
is_called_in_ARM_mode (tree func)
{
  if (TREE_CODE (func) != FUNCTION_DECL)
    abort ();

  /* Ignore the problem about functions whose address is taken.  */
  if (TARGET_CALLEE_INTERWORKING && TREE_PUBLIC (func))
    return TRUE;

#ifdef ARM_PE
  return lookup_attribute ("interfacearm", DECL_ATTRIBUTES (func)) != NULL_TREE;
#else
  return FALSE;
#endif
}

/* The bits which aren't usefully expanded as rtl.  */
const char *
thumb_unexpanded_epilogue (void)
{
  int regno;
  unsigned long live_regs_mask = 0;
  int high_regs_pushed = 0;
  int had_to_push_lr;
  int size;
  int mode;

  if (return_used_this_function)
    return "";

  if (IS_NAKED (arm_current_func_type ()))
    return "";

  live_regs_mask = thumb_compute_save_reg_mask ();
  high_regs_pushed = bit_count (live_regs_mask & 0x0f00);

  /* If we can deduce the registers used from the function's return value.
     This is more reliable that examining regs_ever_live[] because that
     will be set if the register is ever used in the function, not just if
     the register is used to hold a return value.  */

  if (current_function_return_rtx != 0)
    mode = GET_MODE (current_function_return_rtx);
  else
    mode = DECL_MODE (DECL_RESULT (current_function_decl));

  size = GET_MODE_SIZE (mode);

  /* The prolog may have pushed some high registers to use as
     work registers.  e.g. the testsuite file:
     gcc/testsuite/gcc/gcc.c-torture/execute/complex-2.c
     compiles to produce:
        push    {r4, r5, r6, r7, lr}
        mov     r7, r9
        mov     r6, r8
        push    {r6, r7}
     as part of the prolog.  We have to undo that pushing here.  */

  if (high_regs_pushed)
    {
      unsigned long mask = live_regs_mask & 0xff;
      int next_hi_reg;

      /* The available low registers depend on the size of the value we are
         returning.  */
      if (size <= 12)
        mask |=  1 << 3;
      if (size <= 8)
        mask |= 1 << 2;

      if (mask == 0)
        /* Oh dear!  We have no low registers into which we can pop
           high registers!  */
        internal_error
          ("no low registers available for popping high registers");

      for (next_hi_reg = 8; next_hi_reg < 13; next_hi_reg++)
        if (live_regs_mask & (1 << next_hi_reg))
          break;

      while (high_regs_pushed)
        {
          /* Find lo register(s) into which the high register(s) can
             be popped.  */
          for (regno = 0; regno <= LAST_LO_REGNUM; regno++)
            {
              if (mask & (1 << regno))
                high_regs_pushed--;
              if (high_regs_pushed == 0)
                break;
            }

          mask &= (2 << regno) - 1;     /* A noop if regno == 8 */

          /* Pop the values into the low register(s).  */
          thumb_pushpop (asm_out_file, mask, 0, NULL, mask);

          /* Move the value(s) into the high registers.  */
          for (regno = 0; regno <= LAST_LO_REGNUM; regno++)
            {
              if (mask & (1 << regno))
                {
                  asm_fprintf (asm_out_file, "\tmov\t%r, %r\n", next_hi_reg,
                               regno);

                  for (next_hi_reg++; next_hi_reg < 13; next_hi_reg++)
                    if (live_regs_mask & (1 << next_hi_reg))
                      break;
                }
            }
        }
      live_regs_mask &= ~0x0f00;
    }

  had_to_push_lr = (live_regs_mask & (1 << LR_REGNUM)) != 0;
  live_regs_mask &= 0xff;

  if (current_function_pretend_args_size == 0 || TARGET_BACKTRACE)
    {
      /* Pop the return address into the PC.  */
      if (had_to_push_lr)
        live_regs_mask |= 1 << PC_REGNUM;

      /* Either no argument registers were pushed or a backtrace
         structure was created which includes an adjusted stack
         pointer, so just pop everything.  */
      if (live_regs_mask)
        thumb_pushpop (asm_out_file, live_regs_mask, FALSE, NULL,
                       live_regs_mask);

      /* We have either just popped the return address into the
         PC or it is was kept in LR for the entire function.  */
      if (!had_to_push_lr)
        thumb_exit (asm_out_file, LR_REGNUM);
    }
  else
    {
      /* Pop everything but the return address.  */
      if (live_regs_mask)
        thumb_pushpop (asm_out_file, live_regs_mask, FALSE, NULL,
                       live_regs_mask);

      if (had_to_push_lr)
        {
          if (size > 12)
            {
              /* We have no free low regs, so save one.  */
              asm_fprintf (asm_out_file, "\tmov\t%r, %r\n", IP_REGNUM,
                           LAST_ARG_REGNUM);
            }

          /* Get the return address into a temporary register.  */
          thumb_pushpop (asm_out_file, 1 << LAST_ARG_REGNUM, 0, NULL,
                         1 << LAST_ARG_REGNUM);

          if (size > 12)
            {
              /* Move the return address to lr.  */
              asm_fprintf (asm_out_file, "\tmov\t%r, %r\n", LR_REGNUM,
                           LAST_ARG_REGNUM);
              /* Restore the low register.  */
              asm_fprintf (asm_out_file, "\tmov\t%r, %r\n", LAST_ARG_REGNUM,
                           IP_REGNUM);
              regno = LR_REGNUM;
            }
          else
            regno = LAST_ARG_REGNUM;
        }
      else
        regno = LR_REGNUM;

      /* Remove the argument registers that were pushed onto the stack.  */
      asm_fprintf (asm_out_file, "\tadd\t%r, %r, #%d\n",
                   SP_REGNUM, SP_REGNUM,
                   current_function_pretend_args_size);

      thumb_exit (asm_out_file, regno);
    }

  return "";
}

/* Functions to save and restore machine-specific function data.  */
static struct machine_function *
arm_init_machine_status (void)
{
  struct machine_function *machine;
  machine = (machine_function *) ggc_alloc_cleared (sizeof (machine_function));

#if ARM_FT_UNKNOWN != 0
  machine->func_type = ARM_FT_UNKNOWN;
#endif
  return machine;
}

/* Return an RTX indicating where the return address to the
   calling function can be found.  */
rtx
arm_return_addr (int count, rtx frame ATTRIBUTE_UNUSED)
{
  if (count != 0)
    return NULL_RTX;

  return get_hard_reg_initial_val (Pmode, LR_REGNUM);
}

/* Do anything needed before RTL is emitted for each function.  */
void
arm_init_expanders (void)
{
  /* Arrange to initialize and mark the machine per-function status.  */
  init_machine_status = arm_init_machine_status;

  /* This is to stop the combine pass optimizing away the alignment
     adjustment of va_arg.  */
  /* ??? It is claimed that this should not be necessary.  */
  if (cfun)
    mark_reg_pointer (arg_pointer_rtx, PARM_BOUNDARY);
}


/* Like arm_compute_initial_elimination offset.  Simpler because
   THUMB_HARD_FRAME_POINTER isn't actually the ABI specified frame pointer.  */

HOST_WIDE_INT
thumb_compute_initial_elimination_offset (unsigned int from, unsigned int to)
{
  arm_stack_offsets *offsets;

  offsets = arm_get_frame_offsets ();

  switch (from)
    {
    case ARG_POINTER_REGNUM:
      switch (to)
        {
        case STACK_POINTER_REGNUM:
          return offsets->outgoing_args - offsets->saved_args;

        case FRAME_POINTER_REGNUM:
          return offsets->soft_frame - offsets->saved_args;

        case THUMB_HARD_FRAME_POINTER_REGNUM:
        case ARM_HARD_FRAME_POINTER_REGNUM:
          return offsets->saved_regs - offsets->saved_args;

        default:
          abort();
        }
      break;

    case FRAME_POINTER_REGNUM:
      switch (to)
        {
        case STACK_POINTER_REGNUM:
          return offsets->outgoing_args - offsets->soft_frame;

        case THUMB_HARD_FRAME_POINTER_REGNUM:
        case ARM_HARD_FRAME_POINTER_REGNUM:
          return offsets->saved_regs - offsets->soft_frame;

        default:
          abort();
        }
      break;

    default:
      abort ();
    }
}


/* Generate the rest of a function's prologue.  */
void
thumb_expand_prologue (void)
{
  rtx insn, dwarf;

  HOST_WIDE_INT amount;
  arm_stack_offsets *offsets;
  unsigned long func_type;
  int regno;
  unsigned long live_regs_mask;

  func_type = arm_current_func_type ();

  /* Naked functions don't have prologues.  */
  if (IS_NAKED (func_type))
    return;

  if (IS_INTERRUPT (func_type))
    {
      error ("interrupt Service Routines cannot be coded in Thumb mode");
      return;
    }

  live_regs_mask = thumb_compute_save_reg_mask ();
  /* Load the pic register before setting the frame pointer,
     so we can use r7 as a temporary work register.  */
  if (flag_pic)
    arm_load_pic_register (thumb_find_work_register (live_regs_mask));

  offsets = arm_get_frame_offsets ();

  if (frame_pointer_needed)
    {
      insn = emit_insn (gen_movsi (hard_frame_pointer_rtx,
                                   stack_pointer_rtx));
      RTX_FRAME_RELATED_P (insn) = 1;
    }
  else if (CALLER_INTERWORKING_SLOT_SIZE > 0)
    emit_move_insn (gen_rtx_REG (Pmode, ARM_HARD_FRAME_POINTER_REGNUM),
                    stack_pointer_rtx);

  amount = offsets->outgoing_args - offsets->saved_regs;
  if (amount)
    {
      if (amount < 512)
        {
          insn = emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx,
                                        GEN_INT (- amount)));
          RTX_FRAME_RELATED_P (insn) = 1;
        }
      else
        {
          rtx reg;

          /* The stack decrement is too big for an immediate value in a single
             insn.  In theory we could issue multiple subtracts, but after
             three of them it becomes more space efficient to place the full
             value in the constant pool and load into a register.  (Also the
             ARM debugger really likes to see only one stack decrement per
             function).  So instead we look for a scratch register into which
             we can load the decrement, and then we subtract this from the
             stack pointer.  Unfortunately on the thumb the only available
             scratch registers are the argument registers, and we cannot use
             these as they may hold arguments to the function.  Instead we
             attempt to locate a call preserved register which is used by this
             function.  If we can find one, then we know that it will have
             been pushed at the start of the prologue and so we can corrupt
             it now.  */
          for (regno = LAST_ARG_REGNUM + 1; regno <= LAST_LO_REGNUM; regno++)
            if (live_regs_mask & (1 << regno)
                && !(frame_pointer_needed
                     && (regno == THUMB_HARD_FRAME_POINTER_REGNUM)))
              break;

          if (regno > LAST_LO_REGNUM) /* Very unlikely.  */
            {
              rtx spare = gen_rtx_REG (SImode, IP_REGNUM);

              /* Choose an arbitrary, non-argument low register.  */
              reg = gen_rtx_REG (SImode, LAST_LO_REGNUM);

              /* Save it by copying it into a high, scratch register.  */
              emit_insn (gen_movsi (spare, reg));
              /* Add a USE to stop propagate_one_insn() from barfing.  */
              emit_insn (gen_prologue_use (spare));

              /* Decrement the stack.  */
              emit_insn (gen_movsi (reg, GEN_INT (- amount)));
              insn = emit_insn (gen_addsi3 (stack_pointer_rtx,
                                            stack_pointer_rtx, reg));
              RTX_FRAME_RELATED_P (insn) = 1;
              dwarf = gen_rtx_SET (SImode, stack_pointer_rtx,
                                   plus_constant (stack_pointer_rtx,
                                                  -amount));
              RTX_FRAME_RELATED_P (dwarf) = 1;
              REG_NOTES (insn)
                = gen_rtx_EXPR_LIST (REG_FRAME_RELATED_EXPR, dwarf,
                                     REG_NOTES (insn));

              /* Restore the low register's original value.  */
              emit_insn (gen_movsi (reg, spare));

              /* Emit a USE of the restored scratch register, so that flow
                 analysis will not consider the restore redundant.  The
                 register won't be used again in this function and isn't
                 restored by the epilogue.  */
              emit_insn (gen_prologue_use (reg));
            }
          else
            {
              reg = gen_rtx_REG (SImode, regno);

              emit_insn (gen_movsi (reg, GEN_INT (- amount)));

              insn = emit_insn (gen_addsi3 (stack_pointer_rtx,
                                            stack_pointer_rtx, reg));
              RTX_FRAME_RELATED_P (insn) = 1;
              dwarf = gen_rtx_SET (SImode, stack_pointer_rtx,
                                   plus_constant (stack_pointer_rtx,
                                                  -amount));
              RTX_FRAME_RELATED_P (dwarf) = 1;
              REG_NOTES (insn)
                = gen_rtx_EXPR_LIST (REG_FRAME_RELATED_EXPR, dwarf,
                                     REG_NOTES (insn));
            }
        }
      /* If the frame pointer is needed, emit a special barrier that
         will prevent the scheduler from moving stores to the frame
         before the stack adjustment.  */
      if (frame_pointer_needed)
        emit_insn (gen_stack_tie (stack_pointer_rtx,
                                  hard_frame_pointer_rtx));
    }

  if (current_function_profile || TARGET_NO_SCHED_PRO)
    emit_insn (gen_blockage ());

  cfun->machine->lr_save_eliminated = !thumb_force_lr_save ();
  if (live_regs_mask & 0xff)
    cfun->machine->lr_save_eliminated = 0;

  /* If the link register is being kept alive, with the return address in it,
     then make sure that it does not get reused by the ce2 pass.  */
  if (cfun->machine->lr_save_eliminated)
    emit_insn (gen_prologue_use (gen_rtx_REG (SImode, LR_REGNUM)));
}


void
thumb_expand_epilogue (void)
{
  HOST_WIDE_INT amount;
  arm_stack_offsets *offsets;
  int regno;

  /* Naked functions don't have prologues.  */
  if (IS_NAKED (arm_current_func_type ()))
    return;

  offsets = arm_get_frame_offsets ();
  amount = offsets->outgoing_args - offsets->saved_regs;

  if (frame_pointer_needed)
    emit_insn (gen_movsi (stack_pointer_rtx, hard_frame_pointer_rtx));
  else if (amount)
    {
      if (amount < 512)
        emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx,
                               GEN_INT (amount)));
      else
        {
          /* r3 is always free in the epilogue.  */
          rtx reg = gen_rtx_REG (SImode, LAST_ARG_REGNUM);

          emit_insn (gen_movsi (reg, GEN_INT (amount)));
          emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx, reg));
        }
    }

  /* Emit a USE (stack_pointer_rtx), so that
     the stack adjustment will not be deleted.  */
  emit_insn (gen_prologue_use (stack_pointer_rtx));

  if (current_function_profile || TARGET_NO_SCHED_PRO)
    emit_insn (gen_blockage ());

  /* Emit a clobber for each insn that will be restored in the epilogue,
     so that flow2 will get register lifetimes correct.  */
  for (regno = 0; regno < 13; regno++)
    if (regs_ever_live[regno] && !call_used_regs[regno])
      emit_insn (gen_rtx_CLOBBER (VOIDmode, gen_rtx_REG (SImode, regno)));

  if (! regs_ever_live[LR_REGNUM])
    emit_insn (gen_rtx_USE (VOIDmode, gen_rtx_REG (SImode, LR_REGNUM)));
}

static void
thumb_output_function_prologue (FILE *f, HOST_WIDE_INT size ATTRIBUTE_UNUSED)
{
  unsigned long live_regs_mask = 0;
  unsigned long l_mask;
  unsigned high_regs_pushed = 0;
  int cfa_offset = 0;
  int regno;

  if (IS_NAKED (arm_current_func_type ()))
    return;

  if (is_called_in_ARM_mode (current_function_decl))
    {
      const char * name;

      if (GET_CODE (DECL_RTL (current_function_decl)) != MEM)
        abort ();
      if (GET_CODE (XEXP (DECL_RTL (current_function_decl), 0)) != SYMBOL_REF)
        abort ();
      name = XSTR  (XEXP (DECL_RTL (current_function_decl), 0), 0);

      /* Generate code sequence to switch us into Thumb mode.  */
      /* The .code 32 directive has already been emitted by
         ASM_DECLARE_FUNCTION_NAME.  */
      asm_fprintf (f, "\torr\t%r, %r, #1\n", IP_REGNUM, PC_REGNUM);
      asm_fprintf (f, "\tbx\t%r\n", IP_REGNUM);

      /* Generate a label, so that the debugger will notice the
         change in instruction sets.  This label is also used by
         the assembler to bypass the ARM code when this function
         is called from a Thumb encoded function elsewhere in the
         same file.  Hence the definition of STUB_NAME here must
         agree with the definition in gas/config/tc-arm.c.  */

#define STUB_NAME ".real_start_of"

      fprintf (f, "\t.code\t16\n");
#ifdef ARM_PE
      if (arm_dllexport_name_p (name))
        name = arm_strip_name_encoding (name);
#endif
      asm_fprintf (f, "\t.globl %s%U%s\n", STUB_NAME, name);
      fprintf (f, "\t.thumb_func\n");
      asm_fprintf (f, "%s%U%s:\n", STUB_NAME, name);
    }

  if (current_function_pretend_args_size)
    {
      if (cfun->machine->uses_anonymous_args)
        {
          int num_pushes;

          fprintf (f, "\tpush\t{");

          num_pushes = ARM_NUM_INTS (current_function_pretend_args_size);

          for (regno = LAST_ARG_REGNUM + 1 - num_pushes;
               regno <= LAST_ARG_REGNUM;
               regno++)
            asm_fprintf (f, "%r%s", regno,
                         regno == LAST_ARG_REGNUM ? "" : ", ");

          fprintf (f, "}\n");
        }
      else
        asm_fprintf (f, "\tsub\t%r, %r, #%d\n",
                     SP_REGNUM, SP_REGNUM,
                     current_function_pretend_args_size);

      /* We don't need to record the stores for unwinding (would it
         help the debugger any if we did?), but record the change in
         the stack pointer.  */
      if (dwarf2out_do_frame ())
        {
          char *l = dwarf2out_cfi_label ();

          cfa_offset = cfa_offset + current_function_pretend_args_size;
          dwarf2out_def_cfa (l, SP_REGNUM, cfa_offset);
        }
    }

  /* Get the registers we are going to push.  */
  live_regs_mask = thumb_compute_save_reg_mask ();
  /* Extract a mask of the ones we can give to the Thumb's push instruction.  */
  l_mask = live_regs_mask & 0x40ff;
  /* Then count how many other high registers will need to be pushed.  */
  high_regs_pushed = bit_count (live_regs_mask & 0x0f00);

  if (TARGET_BACKTRACE)
    {
      unsigned offset;
      unsigned work_register;

      /* We have been asked to create a stack backtrace structure.
         The code looks like this:

         0   .align 2
         0   func:
         0     sub   SP, #16         Reserve space for 4 registers.
         2     push  {R7}            Push low registers.
         4     add   R7, SP, #20     Get the stack pointer before the push.
         6     str   R7, [SP, #8]    Store the stack pointer (before reserving the space).
         8     mov   R7, PC          Get hold of the start of this code plus 12.
        10     str   R7, [SP, #16]   Store it.
        12     mov   R7, FP          Get hold of the current frame pointer.
        14     str   R7, [SP, #4]    Store it.
        16     mov   R7, LR          Get hold of the current return address.
        18     str   R7, [SP, #12]   Store it.
        20     add   R7, SP, #16     Point at the start of the backtrace structure.
        22     mov   FP, R7          Put this value into the frame pointer.  */

      work_register = thumb_find_work_register (live_regs_mask);

      asm_fprintf
        (f, "\tsub\t%r, %r, #16\t%@ Create stack backtrace structure\n",
         SP_REGNUM, SP_REGNUM);

      if (dwarf2out_do_frame ())
        {
          char *l = dwarf2out_cfi_label ();

          cfa_offset = cfa_offset + 16;
          dwarf2out_def_cfa (l, SP_REGNUM, cfa_offset);
        }

      if (l_mask)
        {
          thumb_pushpop (f, l_mask, 1, &cfa_offset, l_mask);
          offset = bit_count (l_mask);
        }
      else
        offset = 0;

      asm_fprintf (f, "\tadd\t%r, %r, #%d\n", work_register, SP_REGNUM,
                   offset + 16 + current_function_pretend_args_size);

      asm_fprintf (f, "\tstr\t%r, [%r, #%d]\n", work_register, SP_REGNUM,
                   offset + 4);

      /* Make sure that the instruction fetching the PC is in the right place
         to calculate "start of backtrace creation code + 12".  */
      if (l_mask)
        {
          asm_fprintf (f, "\tmov\t%r, %r\n", work_register, PC_REGNUM);
          asm_fprintf (f, "\tstr\t%r, [%r, #%d]\n", work_register, SP_REGNUM,
                       offset + 12);
          asm_fprintf (f, "\tmov\t%r, %r\n", work_register,
                       ARM_HARD_FRAME_POINTER_REGNUM);
          asm_fprintf (f, "\tstr\t%r, [%r, #%d]\n", work_register, SP_REGNUM,
                       offset);
        }
      else
        {
          asm_fprintf (f, "\tmov\t%r, %r\n", work_register,
                       ARM_HARD_FRAME_POINTER_REGNUM);
          asm_fprintf (f, "\tstr\t%r, [%r, #%d]\n", work_register, SP_REGNUM,
                       offset);
          asm_fprintf (f, "\tmov\t%r, %r\n", work_register, PC_REGNUM);
          asm_fprintf (f, "\tstr\t%r, [%r, #%d]\n", work_register, SP_REGNUM,
                       offset + 12);
        }

      asm_fprintf (f, "\tmov\t%r, %r\n", work_register, LR_REGNUM);
      asm_fprintf (f, "\tstr\t%r, [%r, #%d]\n", work_register, SP_REGNUM,
                   offset + 8);
      asm_fprintf (f, "\tadd\t%r, %r, #%d\n", work_register, SP_REGNUM,
                   offset + 12);
      asm_fprintf (f, "\tmov\t%r, %r\t\t%@ Backtrace structure created\n",
                   ARM_HARD_FRAME_POINTER_REGNUM, work_register);
    }
  /* Optimisation:  If we are not pushing any low registers but we are going
     to push some high registers then delay our first push.  This will just
     be a push of LR and we can combine it with the push of the first high
     register.  */
  else if ((l_mask & 0xff) != 0
           || (high_regs_pushed == 0 && l_mask))
    thumb_pushpop (f, l_mask, 1, &cfa_offset, l_mask);

  if (high_regs_pushed)
    {
      unsigned pushable_regs;
      unsigned next_hi_reg;

      for (next_hi_reg = 12; next_hi_reg > LAST_LO_REGNUM; next_hi_reg--)
        if (live_regs_mask & (1 << next_hi_reg))
          break;

      pushable_regs = l_mask & 0xff;

      if (pushable_regs == 0)
        pushable_regs = 1 << thumb_find_work_register (live_regs_mask);

      while (high_regs_pushed > 0)
        {
          unsigned long real_regs_mask = 0;

          for (regno = LAST_LO_REGNUM; regno >= 0; regno --)
            {
              if (pushable_regs & (1 << regno))
                {
                  asm_fprintf (f, "\tmov\t%r, %r\n", regno, next_hi_reg);

                  high_regs_pushed --;
                  real_regs_mask |= (1 << next_hi_reg);

                  if (high_regs_pushed)
                    {
                      for (next_hi_reg --; next_hi_reg > LAST_LO_REGNUM;
                           next_hi_reg --)
                        if (live_regs_mask & (1 << next_hi_reg))
                          break;
                    }
                  else
                    {
                      pushable_regs &= ~((1 << regno) - 1);
                      break;
                    }
                }
            }

          /* If we had to find a work register and we have not yet
             saved the LR then add it to the list of regs to push.  */
          if (l_mask == (1 << LR_REGNUM))
            {
              thumb_pushpop (f, pushable_regs | (1 << LR_REGNUM),
                             1, &cfa_offset,
                             real_regs_mask | (1 << LR_REGNUM));
              l_mask = 0;
            }
          else
            thumb_pushpop (f, pushable_regs, 1, &cfa_offset, real_regs_mask);
        }
    }
}

/* Handle the case of a double word load into a low register from
   a computed memory address.  The computed address may involve a
   register which is overwritten by the load.  */
const char *
thumb_load_double_from_address (rtx *operands)
{
  rtx addr;
  rtx base;
  rtx offset;
  rtx arg1;
  rtx arg2;

  if (GET_CODE (operands[0]) != REG)
    abort ();

  if (GET_CODE (operands[1]) != MEM)
    abort ();

  /* Get the memory address.  */
  addr = XEXP (operands[1], 0);

  /* Work out how the memory address is computed.  */
  switch (GET_CODE (addr))
    {
    case REG:
      operands[2] = gen_rtx_MEM (SImode,
                                 plus_constant (XEXP (operands[1], 0), 4));

      if (REGNO (operands[0]) == REGNO (addr))
        {
          output_asm_insn ("ldr\t%H0, %2", operands);
          output_asm_insn ("ldr\t%0, %1", operands);
        }
      else
        {
          output_asm_insn ("ldr\t%0, %1", operands);
          output_asm_insn ("ldr\t%H0, %2", operands);
        }
      break;

    case CONST:
      /* Compute <address> + 4 for the high order load.  */
      operands[2] = gen_rtx_MEM (SImode,
                                 plus_constant (XEXP (operands[1], 0), 4));

      output_asm_insn ("ldr\t%0, %1", operands);
      output_asm_insn ("ldr\t%H0, %2", operands);
      break;

    case PLUS:
      arg1   = XEXP (addr, 0);
      arg2   = XEXP (addr, 1);

      if (CONSTANT_P (arg1))
        base = arg2, offset = arg1;
      else
        base = arg1, offset = arg2;

      if (GET_CODE (base) != REG)
        abort ();

      /* Catch the case of <address> = <reg> + <reg> */
      if (GET_CODE (offset) == REG)
        {
          int reg_offset = REGNO (offset);
          int reg_base   = REGNO (base);
          int reg_dest   = REGNO (operands[0]);

          /* Add the base and offset registers together into the
             higher destination register.  */
          asm_fprintf (asm_out_file, "\tadd\t%r, %r, %r",
                       reg_dest + 1, reg_base, reg_offset);

          /* Load the lower destination register from the address in
             the higher destination register.  */
          asm_fprintf (asm_out_file, "\tldr\t%r, [%r, #0]",
                       reg_dest, reg_dest + 1);

          /* Load the higher destination register from its own address
             plus 4.  */
          asm_fprintf (asm_out_file, "\tldr\t%r, [%r, #4]",
                       reg_dest + 1, reg_dest + 1);
        }
      else
        {
          /* Compute <address> + 4 for the high order load.  */
          operands[2] = gen_rtx_MEM (SImode,
                                     plus_constant (XEXP (operands[1], 0), 4));

          /* If the computed address is held in the low order register
             then load the high order register first, otherwise always
             load the low order register first.  */
          if (REGNO (operands[0]) == REGNO (base))
            {
              output_asm_insn ("ldr\t%H0, %2", operands);
              output_asm_insn ("ldr\t%0, %1", operands);
            }
          else
            {
              output_asm_insn ("ldr\t%0, %1", operands);
              output_asm_insn ("ldr\t%H0, %2", operands);
            }
        }
      break;

    case LABEL_REF:
      /* With no registers to worry about we can just load the value
         directly.  */
      operands[2] = gen_rtx_MEM (SImode,
                                 plus_constant (XEXP (operands[1], 0), 4));

      output_asm_insn ("ldr\t%H0, %2", operands);
      output_asm_insn ("ldr\t%0, %1", operands);
      break;

    default:
      abort ();
      break;
    }

  return "";
}

const char *
thumb_output_move_mem_multiple (int n, rtx *operands)
{
  rtx tmp;

  switch (n)
    {
    case 2:
      if (REGNO (operands[4]) > REGNO (operands[5]))
        {
          tmp = operands[4];
          operands[4] = operands[5];
          operands[5] = tmp;
        }
      output_asm_insn ("ldmia\t%1!, {%4, %5}", operands);
      output_asm_insn ("stmia\t%0!, {%4, %5}", operands);
      break;

    case 3:
      if (REGNO (operands[4]) > REGNO (operands[5]))
        {
          tmp = operands[4];
          operands[4] = operands[5];
          operands[5] = tmp;
        }
      if (REGNO (operands[5]) > REGNO (operands[6]))
        {
          tmp = operands[5];
          operands[5] = operands[6];
          operands[6] = tmp;
        }
      if (REGNO (operands[4]) > REGNO (operands[5]))
        {
          tmp = operands[4];
          operands[4] = operands[5];
          operands[5] = tmp;
        }

      output_asm_insn ("ldmia\t%1!, {%4, %5, %6}", operands);
      output_asm_insn ("stmia\t%0!, {%4, %5, %6}", operands);
      break;

    default:
      abort ();
    }

  return "";
}

/* Output a call-via instruction for thumb state.  */
const char *
thumb_call_via_reg (rtx reg)
{
  int regno = REGNO (reg);
  rtx *labelp;

  gcc_assert (regno < LR_REGNUM);

  /* If we are in the normal text section we can use a single instance
     per compilation unit.  If we are doing function sections, then we need
     an entry per section, since we can't rely on reachability.  */
  if (in_text_section ())
    {
      thumb_call_reg_needed = 1;

      if (thumb_call_via_label[regno] == NULL)
        thumb_call_via_label[regno] = gen_label_rtx ();
      labelp = thumb_call_via_label + regno;
    }
  else
    {
      if (cfun->machine->call_via[regno] == NULL)
        cfun->machine->call_via[regno] = gen_label_rtx ();
      labelp = cfun->machine->call_via + regno;
    }

  output_asm_insn ("bl\t%a0", labelp);
  return "";
}

/* Routines for generating rtl.  */
void
thumb_expand_movmemqi (rtx *operands)
{
  rtx out = copy_to_mode_reg (SImode, XEXP (operands[0], 0));
  rtx in  = copy_to_mode_reg (SImode, XEXP (operands[1], 0));
  HOST_WIDE_INT len = INTVAL (operands[2]);
  HOST_WIDE_INT offset = 0;

  while (len >= 12)
    {
      emit_insn (gen_movmem12b (out, in, out, in));
      len -= 12;
    }

  if (len >= 8)
    {
      emit_insn (gen_movmem8b (out, in, out, in));
      len -= 8;
    }

  if (len >= 4)
    {
      rtx reg = gen_reg_rtx (SImode);
      emit_insn (gen_movsi (reg, gen_rtx_MEM (SImode, in)));
      emit_insn (gen_movsi (gen_rtx_MEM (SImode, out), reg));
      len -= 4;
      offset += 4;
    }

  if (len >= 2)
    {
      rtx reg = gen_reg_rtx (HImode);
      emit_insn (gen_movhi (reg, gen_rtx_MEM (HImode,
                                              plus_constant (in, offset))));
      emit_insn (gen_movhi (gen_rtx_MEM (HImode, plus_constant (out, offset)),
                            reg));
      len -= 2;
      offset += 2;
    }

  if (len)
    {
      rtx reg = gen_reg_rtx (QImode);
      emit_insn (gen_movqi (reg, gen_rtx_MEM (QImode,
                                              plus_constant (in, offset))));
      emit_insn (gen_movqi (gen_rtx_MEM (QImode, plus_constant (out, offset)),
                            reg));
    }
}

void
thumb_reload_out_hi (rtx *operands)
{
  emit_insn (gen_thumb_movhi_clobber (operands[0], operands[1], operands[2]));
}

/* Handle reading a half-word from memory during reload.  */
void
thumb_reload_in_hi (rtx *operands ATTRIBUTE_UNUSED)
{
  abort ();
}

/* Return the length of a function name prefix
    that starts with the character 'c'.  */
static int
arm_get_strip_length (int c)
{
  switch (c)
    {
    ARM_NAME_ENCODING_LENGTHS
      default: return 0;
    }
}

/* Return a pointer to a function's name with any
   and all prefix encodings stripped from it.  */
const char *
arm_strip_name_encoding (const char *name)
{
  int skip;

  while ((skip = arm_get_strip_length (* name)))
    name += skip;

  return name;
}

/* If there is a '*' anywhere in the name's prefix, then
   emit the stripped name verbatim, otherwise prepend an
   underscore if leading underscores are being used.  */
void
arm_asm_output_labelref (FILE *stream, const char *name)
{
  int skip;
  int verbatim = 0;

  while ((skip = arm_get_strip_length (* name)))
    {
      verbatim |= (*name == '*');
      name += skip;
    }

  if (verbatim)
    fputs (name, stream);
  else
    asm_fprintf (stream, "%U%s", name);
}

static void
arm_file_end (void)
{
  int regno;

  if (! thumb_call_reg_needed)
    return;

  text_section ();
  asm_fprintf (asm_out_file, "\t.code 16\n");
  ASM_OUTPUT_ALIGN (asm_out_file, 1);

  for (regno = 0; regno < LR_REGNUM; regno++)
    {
      rtx label = thumb_call_via_label[regno];

      if (label != 0)
        {
          targetm.asm_out.internal_label (asm_out_file, "L",
                                          CODE_LABEL_NUMBER (label));
          asm_fprintf (asm_out_file, "\tbx\t%r\n", regno);
        }
    }
}

rtx aof_pic_label;

#ifdef AOF_ASSEMBLER
/* Special functions only needed when producing AOF syntax assembler.  */

struct pic_chain
{
  struct pic_chain * next;
  const char * symname;
};

static struct pic_chain * aof_pic_chain = NULL;

rtx
aof_pic_entry (rtx x)
{
  struct pic_chain ** chainp;
  int offset;

  if (aof_pic_label == NULL_RTX)
    {
      aof_pic_label = gen_rtx_SYMBOL_REF (Pmode, "x$adcons");
    }

  for (offset = 0, chainp = &aof_pic_chain; *chainp;
       offset += 4, chainp = &(*chainp)->next)
    if ((*chainp)->symname == XSTR (x, 0))
      return plus_constant (aof_pic_label, offset);

  *chainp = (struct pic_chain *) xmalloc (sizeof (struct pic_chain));
  (*chainp)->next = NULL;
  (*chainp)->symname = XSTR (x, 0);
  return plus_constant (aof_pic_label, offset);
}

void
aof_dump_pic_table (FILE *f)
{
  struct pic_chain * chain;

  if (aof_pic_chain == NULL)
    return;

  asm_fprintf (f, "\tAREA |%r$$adcons|, BASED %r\n",
               PIC_OFFSET_TABLE_REGNUM,
               PIC_OFFSET_TABLE_REGNUM);
  fputs ("|x$adcons|\n", f);

  for (chain = aof_pic_chain; chain; chain = chain->next)
    {
      fputs ("\tDCD\t", f);
      assemble_name (f, chain->symname);
      fputs ("\n", f);
    }
}

int arm_text_section_count = 1;

char *
aof_text_section (void )
{
  static char buf[100];
  sprintf (buf, "\tAREA |C$$code%d|, CODE, READONLY",
           arm_text_section_count++);
  if (flag_pic)
    strcat (buf, ", PIC, REENTRANT");
  return buf;
}

static int arm_data_section_count = 1;

char *
aof_data_section (void)
{
  static char buf[100];
  sprintf (buf, "\tAREA |C$$data%d|, DATA", arm_data_section_count++);
  return buf;
}

/* The AOF assembler is religiously strict about declarations of
   imported and exported symbols, so that it is impossible to declare
   a function as imported near the beginning of the file, and then to
   export it later on.  It is, however, possible to delay the decision
   until all the functions in the file have been compiled.  To get
   around this, we maintain a list of the imports and exports, and
   delete from it any that are subsequently defined.  At the end of
   compilation we spit the remainder of the list out before the END
   directive.  */

struct import
{
  struct import * next;
  const char * name;
};

static struct import * imports_list = NULL;

void
aof_add_import (const char *name)
{
  struct import * new;

  for (new = imports_list; new; new = new->next)
    if (new->name == name)
      return;

  new = (struct import *) xmalloc (sizeof (struct import));
  new->next = imports_list;
  imports_list = new;
  new->name = name;
}

void
aof_delete_import (const char *name)
{
  struct import ** old;

  for (old = &imports_list; *old; old = & (*old)->next)
    {
      if ((*old)->name == name)
        {
          *old = (*old)->next;
          return;
        }
    }
}

int arm_main_function = 0;

static void
aof_dump_imports (FILE *f)
{
  /* The AOF assembler needs this to cause the startup code to be extracted
     from the library.  Brining in __main causes the whole thing to work
     automagically.  */
  if (arm_main_function)
    {
      text_section ();
      fputs ("\tIMPORT __main\n", f);
      fputs ("\tDCD __main\n", f);
    }

  /* Now dump the remaining imports.  */
  while (imports_list)
    {
      fprintf (f, "\tIMPORT\t");
      assemble_name (f, imports_list->name);
      fputc ('\n', f);
      imports_list = imports_list->next;
    }
}

static void
aof_globalize_label (FILE *stream, const char *name)
{
  default_globalize_label (stream, name);
  if (! strcmp (name, "main"))
    arm_main_function = 1;
}

static void
aof_file_start (void)
{
  fputs ("__r0\tRN\t0\n", asm_out_file);
  fputs ("__a1\tRN\t0\n", asm_out_file);
  fputs ("__a2\tRN\t1\n", asm_out_file);
  fputs ("__a3\tRN\t2\n", asm_out_file);
  fputs ("__a4\tRN\t3\n", asm_out_file);
  fputs ("__v1\tRN\t4\n", asm_out_file);
  fputs ("__v2\tRN\t5\n", asm_out_file);
  fputs ("__v3\tRN\t6\n", asm_out_file);
  fputs ("__v4\tRN\t7\n", asm_out_file);
  fputs ("__v5\tRN\t8\n", asm_out_file);
  fputs ("__v6\tRN\t9\n", asm_out_file);
  fputs ("__sl\tRN\t10\n", asm_out_file);
  fputs ("__fp\tRN\t11\n", asm_out_file);
  fputs ("__ip\tRN\t12\n", asm_out_file);
  fputs ("__sp\tRN\t13\n", asm_out_file);
  fputs ("__lr\tRN\t14\n", asm_out_file);
  fputs ("__pc\tRN\t15\n", asm_out_file);
  fputs ("__f0\tFN\t0\n", asm_out_file);
  fputs ("__f1\tFN\t1\n", asm_out_file);
  fputs ("__f2\tFN\t2\n", asm_out_file);
  fputs ("__f3\tFN\t3\n", asm_out_file);
  fputs ("__f4\tFN\t4\n", asm_out_file);
  fputs ("__f5\tFN\t5\n", asm_out_file);
  fputs ("__f6\tFN\t6\n", asm_out_file);
  fputs ("__f7\tFN\t7\n", asm_out_file);
  text_section ();
}

static void
aof_file_end (void)
{
  if (flag_pic)
    aof_dump_pic_table (asm_out_file);
  arm_file_end ();
  aof_dump_imports (asm_out_file);
  fputs ("\tEND\n", asm_out_file);
}
#endif /* AOF_ASSEMBLER */

#ifndef ARM_PE
/* Symbols in the text segment can be accessed without indirecting via the
   constant pool; it may take an extra binary operation, but this is still
   faster than indirecting via memory.  Don't do this when not optimizing,
   since we won't be calculating al of the offsets necessary to do this
   simplification.  */

static void
arm_encode_section_info (tree decl, rtx rtl, int first)
{
  /* This doesn't work with AOF syntax, since the string table may be in
     a different AREA.  */
#ifndef AOF_ASSEMBLER
  if (optimize > 0 && TREE_CONSTANT (decl))
    SYMBOL_REF_FLAG (XEXP (rtl, 0)) = 1;
#endif

  /* If we are referencing a function that is weak then encode a long call
     flag in the function name, otherwise if the function is static or
     or known to be defined in this file then encode a short call flag.  */
  if (first && DECL_P (decl))
    {
      if (TREE_CODE (decl) == FUNCTION_DECL && DECL_WEAK (decl))
        arm_encode_call_attribute (decl, LONG_CALL_FLAG_CHAR);
      else if (! TREE_PUBLIC (decl))
        arm_encode_call_attribute (decl, SHORT_CALL_FLAG_CHAR);
    }
}
#endif /* !ARM_PE */

static void
arm_internal_label (FILE *stream, const char *prefix, unsigned long labelno)
{
  if (arm_ccfsm_state == 3 && (unsigned) arm_target_label == labelno
      && !strcmp (prefix, "L"))
    {
      arm_ccfsm_state = 0;
      arm_target_insn = NULL;
    }
  default_internal_label (stream, prefix, labelno);
}

/* Output code to add DELTA to the first argument, and then jump
   to FUNCTION.  Used for C++ multiple inheritance.  */
static void
arm_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
                     HOST_WIDE_INT delta,
                     HOST_WIDE_INT vcall_offset ATTRIBUTE_UNUSED,
                     tree function)
{
  static int thunk_label = 0;
  char label[256];
  int mi_delta = delta;
  const char *const mi_op = mi_delta < 0 ? "sub" : "add";
  int shift = 0;
  int this_regno = (aggregate_value_p (TREE_TYPE (TREE_TYPE (function)), function)
                    ? 1 : 0);
  if (mi_delta < 0)
    mi_delta = - mi_delta;
  if (TARGET_THUMB)
    {
      int labelno = thunk_label++;
      ASM_GENERATE_INTERNAL_LABEL (label, "LTHUMBFUNC", labelno);
      fputs ("\tldr\tr12, ", file);
      assemble_name (file, label);
      fputc ('\n', file);
    }
  while (mi_delta != 0)
    {
      if ((mi_delta & (3 << shift)) == 0)
        shift += 2;
      else
        {
          asm_fprintf (file, "\t%s\t%r, %r, #%d\n",
                       mi_op, this_regno, this_regno,
                       mi_delta & (0xff << shift));
          mi_delta &= ~(0xff << shift);
          shift += 8;
        }
    }
  if (TARGET_THUMB)
    {
      fprintf (file, "\tbx\tr12\n");
      ASM_OUTPUT_ALIGN (file, 2);
      assemble_name (file, label);
      fputs (":\n", file);
      assemble_integer (XEXP (DECL_RTL (function), 0), 4, BITS_PER_WORD, 1);
    }
  else
    {
      fputs ("\tb\t", file);
      assemble_name (file, XSTR (XEXP (DECL_RTL (function), 0), 0));
      if (NEED_PLT_RELOC)
        fputs ("(PLT)", file);
      fputc ('\n', file);
    }
}

int
arm_emit_vector_const (FILE *file, rtx x)
{
  int i;
  const char * pattern;

  if (GET_CODE (x) != CONST_VECTOR)
    abort ();

  switch (GET_MODE (x))
    {
    case V2SImode: pattern = "%08x"; break;
    case V4HImode: pattern = "%04x"; break;
    case V8QImode: pattern = "%02x"; break;
    default:       abort ();
    }

  fprintf (file, "0x");
  for (i = CONST_VECTOR_NUNITS (x); i--;)
    {
      rtx element;

      element = CONST_VECTOR_ELT (x, i);
      fprintf (file, pattern, INTVAL (element));
    }

  return 1;
}

const char *
arm_output_load_gr (rtx *operands)
{
  rtx reg;
  rtx offset;
  rtx wcgr;
  rtx sum;

  if (GET_CODE (operands [1]) != MEM
      || GET_CODE (sum = XEXP (operands [1], 0)) != PLUS
      || GET_CODE (reg = XEXP (sum, 0)) != REG
      || GET_CODE (offset = XEXP (sum, 1)) != CONST_INT
      || ((INTVAL (offset) < 1024) && (INTVAL (offset) > -1024)))
    return "wldrw%?\t%0, %1";

  /* Fix up an out-of-range load of a GR register.  */
  output_asm_insn ("str%?\t%0, [sp, #-4]!\t@ Start of GR load expansion", & reg);
  wcgr = operands[0];
  operands[0] = reg;
  output_asm_insn ("ldr%?\t%0, %1", operands);

  operands[0] = wcgr;
  operands[1] = reg;
  output_asm_insn ("tmcr%?\t%0, %1", operands);
  output_asm_insn ("ldr%?\t%0, [sp], #4\t@ End of GR load expansion", & reg);

  return "";
}

static rtx
arm_struct_value_rtx (tree fntype ATTRIBUTE_UNUSED,
                      int incoming ATTRIBUTE_UNUSED)
{
#if 0
  /* FIXME: The ARM backend has special code to handle structure
         returns, and will reserve its own hidden first argument.  So
         if this macro is enabled a *second* hidden argument will be
         reserved, which will break binary compatibility with old
         toolchains and also thunk handling.  One day this should be
         fixed.  */
  return 0;
#else
  /* Register in which address to store a structure value
     is passed to a function.  */
  return gen_rtx_REG (Pmode, ARG_REGISTER (1));
#endif
}

/* Worker function for TARGET_SETUP_INCOMING_VARARGS.

   On the ARM, PRETEND_SIZE is set in order to have the prologue push the last
   named arg and all anonymous args onto the stack.
   XXX I know the prologue shouldn't be pushing registers, but it is faster
   that way.  */

static void
arm_setup_incoming_varargs (CUMULATIVE_ARGS *cum,
                            enum machine_mode mode ATTRIBUTE_UNUSED,
                            tree type ATTRIBUTE_UNUSED,
                            int *pretend_size,
                            int second_time ATTRIBUTE_UNUSED)
{
  cfun->machine->uses_anonymous_args = 1;
  if (cum->nregs < NUM_ARG_REGS)
    *pretend_size = (NUM_ARG_REGS - cum->nregs) * UNITS_PER_WORD;
}

/* Return nonzero if the CONSUMER instruction (a store) does not need
   PRODUCER's value to calculate the address.  */

int
arm_no_early_store_addr_dep (rtx producer, rtx consumer)
{
  rtx value = PATTERN (producer);
  rtx addr = PATTERN (consumer);

  if (GET_CODE (value) == COND_EXEC)
    value = COND_EXEC_CODE (value);
  if (GET_CODE (value) == PARALLEL)
    value = XVECEXP (value, 0, 0);
  value = XEXP (value, 0);
  if (GET_CODE (addr) == COND_EXEC)
    addr = COND_EXEC_CODE (addr);
  if (GET_CODE (addr) == PARALLEL)
    addr = XVECEXP (addr, 0, 0);
  addr = XEXP (addr, 0);

  return !reg_overlap_mentioned_p (value, addr);
}

/* Return nonzero if the CONSUMER instruction (an ALU op) does not
   have an early register shift value or amount dependency on the
   result of PRODUCER.  */

int
arm_no_early_alu_shift_dep (rtx producer, rtx consumer)
{
  rtx value = PATTERN (producer);
  rtx op = PATTERN (consumer);
  rtx early_op;

  if (GET_CODE (value) == COND_EXEC)
    value = COND_EXEC_CODE (value);
  if (GET_CODE (value) == PARALLEL)
    value = XVECEXP (value, 0, 0);
  value = XEXP (value, 0);
  if (GET_CODE (op) == COND_EXEC)
    op = COND_EXEC_CODE (op);
  if (GET_CODE (op) == PARALLEL)
    op = XVECEXP (op, 0, 0);
  op = XEXP (op, 1);

  early_op = XEXP (op, 0);
  /* This is either an actual independent shift, or a shift applied to
     the first operand of another operation.  We want the whole shift
     operation.  */
  if (GET_CODE (early_op) == REG)
    early_op = op;

  return !reg_overlap_mentioned_p (value, early_op);
}

/* Return nonzero if the CONSUMER instruction (an ALU op) does not
   have an early register shift value dependency on the result of
   PRODUCER.  */

int
arm_no_early_alu_shift_value_dep (rtx producer, rtx consumer)
{
  rtx value = PATTERN (producer);
  rtx op = PATTERN (consumer);
  rtx early_op;

  if (GET_CODE (value) == COND_EXEC)
    value = COND_EXEC_CODE (value);
  if (GET_CODE (value) == PARALLEL)
    value = XVECEXP (value, 0, 0);
  value = XEXP (value, 0);
  if (GET_CODE (op) == COND_EXEC)
    op = COND_EXEC_CODE (op);
  if (GET_CODE (op) == PARALLEL)
    op = XVECEXP (op, 0, 0);
  op = XEXP (op, 1);

  early_op = XEXP (op, 0);

  /* This is either an actual independent shift, or a shift applied to
     the first operand of another operation.  We want the value being
     shifted, in either case.  */
  if (GET_CODE (early_op) != REG)
    early_op = XEXP (early_op, 0);

  return !reg_overlap_mentioned_p (value, early_op);
}

/* Return nonzero if the CONSUMER (a mul or mac op) does not
   have an early register mult dependency on the result of
   PRODUCER.  */

int
arm_no_early_mul_dep (rtx producer, rtx consumer)
{
  rtx value = PATTERN (producer);
  rtx op = PATTERN (consumer);

  if (GET_CODE (value) == COND_EXEC)
    value = COND_EXEC_CODE (value);
  if (GET_CODE (value) == PARALLEL)
    value = XVECEXP (value, 0, 0);
  value = XEXP (value, 0);
  if (GET_CODE (op) == COND_EXEC)
    op = COND_EXEC_CODE (op);
  if (GET_CODE (op) == PARALLEL)
    op = XVECEXP (op, 0, 0);
  op = XEXP (op, 1);

  return (GET_CODE (op) == PLUS
          && !reg_overlap_mentioned_p (value, XEXP (op, 0)));
}


/* We can't rely on the caller doing the proper promotion when
   using APCS or ATPCS.  */

static bool
arm_promote_prototypes (tree t ATTRIBUTE_UNUSED)
{
    return !TARGET_AAPCS_BASED;
}


/* AAPCS based ABIs use short enums by default.  */

static bool
arm_default_short_enums (void)
{
  return TARGET_AAPCS_BASED;
}


/* AAPCS requires that anonymous bitfields affect structure alignment.  */

static bool
arm_align_anon_bitfield (void)
{
  return TARGET_AAPCS_BASED;
}


/* The generic C++ ABI says 64-bit (long long).  The EABI says 32-bit.  */

static tree
arm_cxx_guard_type (void)
{
  return TARGET_AAPCS_BASED ? integer_type_node : long_long_integer_type_node;
}


/* The EABI says test the least significan bit of a guard variable.  */

static bool
arm_cxx_guard_mask_bit (void)
{
  return TARGET_AAPCS_BASED;
}


/* The EABI specifies that all array cookies are 8 bytes long.  */

static tree
arm_get_cookie_size (tree type)
{
  tree size;

  if (!TARGET_AAPCS_BASED)
    return default_cxx_get_cookie_size (type);

  size = build_int_cst (sizetype, 8);
  return size;
}


/* The EABI says that array cookies should also contain the element size.  */

static bool
arm_cookie_has_size (void)
{
  return TARGET_AAPCS_BASED;
}


/* The EABI says constructors and destructors should return a pointer to
   the object constructed/destroyed.  */

static bool
arm_cxx_cdtor_returns_this (void)
{
  return TARGET_AAPCS_BASED;
}

/* The EABI says that an inline function may never be the key
   method.  */

static bool
arm_cxx_key_method_may_be_inline (void)
{
  return !TARGET_AAPCS_BASED;
}

static void
arm_cxx_determine_class_data_visibility (tree decl)
{
  if (!TARGET_AAPCS_BASED)
    return;

  /* In general, \S 3.2.5.5 of the ARM EABI requires that class data
     is exported.  However, on systems without dynamic vague linkage,
     \S 3.2.5.6 says that COMDAT class data has hidden linkage.  */
  if (!TARGET_ARM_DYNAMIC_VAGUE_LINKAGE_P && DECL_COMDAT (decl))
    DECL_VISIBILITY (decl) = VISIBILITY_HIDDEN;
  else
    DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
  DECL_VISIBILITY_SPECIFIED (decl) = 1;
}
  
static bool
arm_cxx_class_data_always_comdat (void)
{
  /* \S 3.2.5.4 of the ARM C++ ABI says that class data only have
     vague linkage if the class has no key function.  */
  return !TARGET_AAPCS_BASED;
}


/* The EABI says __aeabi_atexit should be used to register static
   destructors.  */

static bool
arm_cxx_use_aeabi_atexit (void)
{
  return TARGET_AAPCS_BASED;
}


void
arm_set_return_address (rtx source, rtx scratch)
{
  arm_stack_offsets *offsets;
  HOST_WIDE_INT delta;
  rtx addr;
  unsigned long saved_regs;

  saved_regs = arm_compute_save_reg_mask ();

  if ((saved_regs & (1 << LR_REGNUM)) == 0)
    emit_move_insn (gen_rtx_REG (Pmode, LR_REGNUM), source);
  else
    {
      if (frame_pointer_needed)
        addr = plus_constant(hard_frame_pointer_rtx, -4);
      else
        {
          /* LR will be the first saved register.  */
          offsets = arm_get_frame_offsets ();
          delta = offsets->outgoing_args - (offsets->frame + 4);


          if (delta >= 4096)
            {
              emit_insn (gen_addsi3 (scratch, stack_pointer_rtx,
                                     GEN_INT (delta & ~4095)));
              addr = scratch;
              delta &= 4095;
            }
          else
            addr = stack_pointer_rtx;

          addr = plus_constant (addr, delta);
        }
      emit_move_insn (gen_rtx_MEM (Pmode, addr), source);
    }
}


void
thumb_set_return_address (rtx source, rtx scratch)
{
  arm_stack_offsets *offsets;
  HOST_WIDE_INT delta;
  int reg;
  rtx addr;
  unsigned long mask;

  emit_insn (gen_rtx_USE (VOIDmode, source));

  mask = thumb_compute_save_reg_mask ();
  if (mask & (1 << LR_REGNUM))
    {
      offsets = arm_get_frame_offsets ();

      /* Find the saved regs.  */
      if (frame_pointer_needed)
        {
          delta = offsets->soft_frame - offsets->saved_args;
          reg = THUMB_HARD_FRAME_POINTER_REGNUM;
        }
      else
        {
          delta = offsets->outgoing_args - offsets->saved_args;
          reg = SP_REGNUM;
        }
      /* Allow for the stack frame.  */
      if (TARGET_BACKTRACE)
        delta -= 16;
      /* The link register is always the first saved register.  */
      delta -= 4;

      /* Construct the address.  */
      addr = gen_rtx_REG (SImode, reg);
      if ((reg != SP_REGNUM && delta >= 128)
          || delta >= 1024)
        {
          emit_insn (gen_movsi (scratch, GEN_INT (delta)));
          emit_insn (gen_addsi3 (scratch, scratch, stack_pointer_rtx));
          addr = scratch;
        }
      else
        addr = plus_constant (addr, delta);

      emit_move_insn (gen_rtx_MEM (Pmode, addr), source);
    }
  else
    emit_move_insn (gen_rtx_REG (Pmode, LR_REGNUM), source);
}

/* Implements target hook vector_mode_supported_p.  */
bool
arm_vector_mode_supported_p (enum machine_mode mode)
{
  if ((mode == V2SImode)
      || (mode == V4HImode)
      || (mode == V8QImode))
    return true;

  return false;
}

/* Implement TARGET_SHIFT_TRUNCATION_MASK.  SImode shifts use normal
   ARM insns and therefore guarantee that the shift count is modulo 256.
   DImode shifts (those implemented by lib1funcs.asm or by optabs.c)
   guarantee no particular behavior for out-of-range counts.  */

static unsigned HOST_WIDE_INT
arm_shift_truncation_mask (enum machine_mode mode)
{
  return mode == SImode ? 255 : 0;
}


/* Map internal gcc register numbers to DWARF2 register numbers.  */

unsigned int
arm_dbx_register_number (unsigned int regno)
{
  if (regno < 16)
    return regno;

  /* TODO: Legacy targets output FPA regs as registers 16-23 for backwards
     compatibility.  The EABI defines them as registers 96-103.  */
  if (IS_FPA_REGNUM (regno))
    return (TARGET_AAPCS_BASED ? 96 : 16) + regno - FIRST_FPA_REGNUM;

  if (IS_VFP_REGNUM (regno))
    return 64 + regno - FIRST_VFP_REGNUM;

  if (IS_IWMMXT_GR_REGNUM (regno))
    return 104 + regno - FIRST_IWMMXT_GR_REGNUM;

  if (IS_IWMMXT_REGNUM (regno))
    return 112 + regno - FIRST_IWMMXT_REGNUM;

  abort ();
}