gcc/config/m68k/m68kv4.h

   1 /* Target definitions for GNU compiler for mc680x0 running System V.4
   2    Copyright (C) 1991, 1993, 1994, 1995, 1996, 1998, 1999, 2000
   3    Free Software Foundation, Inc.
   4    Contributed by Ron Guilmette (rfg@monkeys.com) and
   5    Fred Fish (fnf@cygnus.com).
   6
   7 This file is part of GNU CC.
   8
   9 GNU CC is free software; you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation; either version 2, or (at your option)
  12 any later version.
  13
  14 GNU CC is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GNU CC; see the file COPYING.  If not, write to
  21 the Free Software Foundation, 59 Temple Place - Suite 330,
  22 Boston, MA 02111-1307, USA.  */
  23
  24 /* Use SGS_* macros to control compilation in m68k.md */
  25
  26 #define SGS_SWITCH_TABLES       /* Different switch table handling */
  27
  28 /* TODO: convert includes to ${tm_file} list in config.gcc.  */
  29 #include "m68k/sgs.h"           /* The m68k/SVR4 assembler is SGS based */
  30
  31 #include "dbxelf.h"
  32 #include "elfos.h"
  33 #include "svr4.h"               /* Pick up the generic SVR4 macros */
  34
  35 /* See m68k.h.  7 means 68020 with 68881.  */
  36
  37 #ifndef TARGET_DEFAULT
  38 #define TARGET_DEFAULT (MASK_BITFIELD|MASK_68881|MASK_68020)
  39 #endif
  40
  41 /*  Override the definition of NO_DOLLAR_IN_LABEL in svr4.h, for special
  42     g++ assembler names.  When this is defined, g++ uses embedded '.'
  43     characters and some m68k assemblers have problems with this.  The
  44     chances are much greater that any particular assembler will permit
  45     embedded '$' characters.  */
  46
  47 #undef NO_DOLLAR_IN_LABEL
  48
  49 /* Define PCC_STATIC_STRUCT_RETURN if the convention on the target machine
  50    is to use the nonreentrant technique for returning structure and union
  51    values, as commonly implemented by the AT&T Portable C Compiler (PCC).
  52    When defined, the gcc option -fpcc-struct-return can be used to cause
  53    this form to be generated.  When undefined, the option does nothing.
  54    For m68k SVR4, the convention is to use a reentrant technique compatible
  55    with the gcc default, so override the definition of this macro in m68k.h */
  56
  57 #undef PCC_STATIC_STRUCT_RETURN
  58
  59 /* Provide a set of pre-definitions and pre-assertions appropriate for
  60    the m68k running svr4.  __svr4__ is our extension.  */
  61
  62 #define CPP_PREDEFINES \
  63   "-Dm68k -Dunix -D__svr4__ -D__motorola__ \
  64  -Asystem=unix -Asystem=svr4 -Acpu=m68k -Amachine=m68k"
  65
  66 /* Test to see if the target includes a 68881 by default, and use CPP_SPEC
  67    to control whether or not __HAVE_68881__ is defined by default or not.
  68    If a 68881 is the default, gcc will use inline 68881 instructions, by
  69    predefining __HAVE_68881__, unless -msoft-float is specified.
  70    If a 68881 is not the default, gcc will only define __HAVE_68881__ if
  71    -m68881 is specified.  */
  72
  73 #if TARGET_DEFAULT & MASK_68881
  74 #define CPP_SPEC "%{!msoft-float:-D__HAVE_68881__}"
  75 #else
  76 #define CPP_SPEC "%{m68881:-D__HAVE_68881__}"
  77 #endif
  78
  79 /* Output assembler code to FILE to increment profiler label # LABELNO
  80    for profiling a function entry.  We override the definition in m68k.h
  81    and match the way the native m68k/SVR4 compiler does profiling, with the
  82    address of the profile counter in a1, not a0, and using bsr rather
  83    than jsr.  */
  84
  85 #undef FUNCTION_PROFILER
  86 #define FUNCTION_PROFILER(FILE, LABELNO)                                \
  87   asm_fprintf ((FILE), "\tlea.l\t(%LLP%d,%Rpc),%Ra1\n\tbsr\t_mcount\n", \
  88                (LABELNO))
  89
  90 /* Local common symbols are declared to the assembler with ".lcomm" rather
  91    than ".bss", so override the definition in svr4.h */
  92 /* ??? svr4.h no longer defines this, and this is only used by m68k/amix.h.  */
  93
  94 #undef BSS_ASM_OP
  95 #define BSS_ASM_OP      "\t.lcomm\t"
  96
  97 /* Register in which address to store a structure value is passed to a
  98    function.  The default in m68k.h is a1.  For m68k/SVR4 it is a0.  */
  99
 100 #undef STRUCT_VALUE_REGNUM
 101 #define STRUCT_VALUE_REGNUM 8
 102
 103 /* Register in which static-chain is passed to a function.  The
 104    default in m68k.h is a0, but that is already the struct value
 105    regnum.  Make it a1 instead.  */
 106
 107 #undef STATIC_CHAIN_REGNUM
 108 #define STATIC_CHAIN_REGNUM 9
 109
 110 #define ASM_COMMENT_START "#"
 111
 112 /* Define how the m68k registers should be numbered for Dwarf output.
 113    The numbering provided here should be compatible with the native
 114    SVR4 SDB debugger in the m68k/SVR4 reference port, where d0-d7
 115    are 0-7, a0-a8 are 8-15, and fp0-fp7 are 16-23.  */
 116
 117 #define DBX_REGISTER_NUMBER(REGNO) (REGNO)
 118
 119 /* The ASM_OUTPUT_SKIP macro is first defined in m68k.h, using ".skip".
 120    It is then overridden by m68k/sgs.h to use ".space", and again by svr4.h
 121    to use ".zero".  The m68k/SVR4 assembler uses ".space", so repeat the
 122    definition from m68k/sgs.h here.  Note that ASM_NO_SKIP_IN_TEXT is
 123    defined in m68k/sgs.h, so we don't have to repeat it here.  */
 124
 125 #undef ASM_OUTPUT_SKIP
 126 #define ASM_OUTPUT_SKIP(FILE,SIZE)  \
 127   fprintf (FILE, "%s%u\n", SPACE_ASM_OP, (SIZE))
 128
 129 /* 1 if N is a possible register number for a function value.
 130    For m68k/SVR4 allow d0, a0, or fp0 as return registers, for integral,
 131    pointer, or floating types, respectively. Reject fp0 if not using a
 132    68881 coprocessor.  */
 133
 134 #undef FUNCTION_VALUE_REGNO_P
 135 #define FUNCTION_VALUE_REGNO_P(N) \
 136   ((N) == 0 || (N) == 8 || (TARGET_68881 && (N) == 16))
 137
 138 /* Define this to be true when FUNCTION_VALUE_REGNO_P is true for
 139    more than one register.  */
 140
 141 #undef NEEDS_UNTYPED_CALL
 142 #define NEEDS_UNTYPED_CALL 1
 143
 144 /* Define how to generate (in the callee) the output value of a function
 145    and how to find (in the caller) the value returned by a function.  VALTYPE
 146    is the data type of the value (as a tree).  If the precise function being
 147    called is known, FUNC is its FUNCTION_DECL; otherwise, FUNC is 0.
 148    For m68k/SVR4 generate the result in d0, a0, or fp0 as appropriate.  */
 149
 150 #undef FUNCTION_VALUE
 151 #define FUNCTION_VALUE(VALTYPE, FUNC)                                   \
 152   (TREE_CODE (VALTYPE) == REAL_TYPE && TARGET_68881                     \
 153    ? gen_rtx_REG (TYPE_MODE (VALTYPE), 16)                              \
 154    : (POINTER_TYPE_P (VALTYPE)                                          \
 155       ? gen_rtx_REG (TYPE_MODE (VALTYPE), 8)                            \
 156       : gen_rtx_REG (TYPE_MODE (VALTYPE), 0)))
 157
 158 /* For compatibility with the large body of existing code which does not
 159    always properly declare external functions returning pointer types, the
 160    m68k/SVR4 convention is to copy the value returned for pointer functions
 161    from a0 to d0 in the function epilogue, so that callers that have
 162    neglected to properly declare the callee can still find the correct return
 163    value.  */
 164
 165 #define FUNCTION_EXTRA_EPILOGUE(FILE, SIZE)                             \
 166 do {                                                                    \
 167   if (current_function_returns_pointer                                  \
 168       && ! find_equiv_reg (0, get_last_insn (), 0, 0, 0, 8, Pmode))     \
 169     asm_fprintf (FILE, "\tmov.l %Ra0,%Rd0\n");                          \
 170 } while (0);
 171
 172 /* Define how to find the value returned by a library function assuming the
 173    value has mode MODE.
 174    For m68k/SVR4 look for integer values in d0, pointer values in d0
 175    (returned in both d0 and a0), and floating values in fp0.  */
 176
 177 #undef LIBCALL_VALUE
 178 #define LIBCALL_VALUE(MODE)                                             \
 179   ((((MODE) == SFmode || (MODE) == DFmode || (MODE) == XFmode)          \
 180     && TARGET_68881)                                                    \
 181    ? gen_rtx_REG ((MODE), 16)                                           \
 182    : gen_rtx_REG ((MODE), 0))
 183
 184 /* Boundary (in *bits*) on which stack pointer should be aligned.
 185    The m68k/SVR4 convention is to keep the stack pointer longword aligned.  */
 186
 187 #undef STACK_BOUNDARY
 188 #define STACK_BOUNDARY 32
 189
 190 /* Alignment of field after `int : 0' in a structure.
 191    For m68k/SVR4, this is the next longword boundary.  */
 192
 193 #undef EMPTY_FIELD_BOUNDARY
 194 #define EMPTY_FIELD_BOUNDARY 32
 195
 196 /* No data type wants to be aligned rounder than this.
 197    For m68k/SVR4, some types (doubles for example) are aligned on 8 byte
 198    boundaries */
 199
 200 #undef BIGGEST_ALIGNMENT
 201 #define BIGGEST_ALIGNMENT 64
 202
 203 /* SVR4 m68k assembler is bitching on the `comm i,1,1' which asks for
 204    1 byte alignment. Don't generate alignment for COMMON seems to be
 205    safer until we the assembler is fixed.  */
 206 #undef ASM_OUTPUT_ALIGNED_COMMON
 207 /* Same problem with this one.  */
 208 #undef ASM_OUTPUT_ALIGNED_LOCAL
 209
 210 /* The `string' directive on m68k svr4 does not handle string with
 211    escape char (ie., `\') right. Use normal way to output ASCII bytes
 212    seems to be safer.  */
 213 #undef ASM_OUTPUT_ASCII
 214 #define ASM_OUTPUT_ASCII(FILE,PTR,LEN)                          \
 215 do {                                                            \
 216   register size_t sp = 0, limit = (LEN);                        \
 217   fputs (integer_asm_op (1, TRUE), (FILE));                     \
 218   do {                                                          \
 219     int ch = (PTR)[sp];                                         \
 220     if (ch > ' ' && ! (ch & 0x80) && ch != '\\')                \
 221       {                                                         \
 222         fprintf ((FILE), "'%c", ch);                            \
 223       }                                                         \
 224     else                                                        \
 225       {                                                         \
 226         fprintf ((FILE), "0x%x", ch);                           \
 227       }                                                         \
 228     if (++sp < limit)                                           \
 229       {                                                         \
 230         if ((sp % 10) == 0)                                     \
 231           {                                                     \
 232             fprintf ((FILE), "\n%s", integer_asm_op (1, TRUE)); \
 233           }                                                     \
 234         else                                                    \
 235           {                                                     \
 236             putc (',', (FILE));                                 \
 237           }                                                     \
 238       }                                                         \
 239   } while (sp < limit);                                         \
 240   putc ('\n', (FILE));                                          \
 241 } while (0)
 242
 243 /* SVR4 m68k assembler is bitching on the syntax `2.b'.
 244    So use the "LLDnnn-LLnnn" format.  Define LLDnnn after the table.  */
 245
 246 #undef ASM_OUTPUT_CASE_END
 247 #define ASM_OUTPUT_CASE_END(FILE,NUM,TABLE)                             \
 248 do {                                                                    \
 249   if (switch_table_difference_label_flag)                               \
 250     asm_fprintf ((FILE), "%s%LLD%d,%LL%d\n", SET_ASM_OP, (NUM), (NUM)); \
 251   switch_table_difference_label_flag = 0;                               \
 252 } while (0)
 253
 254 int switch_table_difference_label_flag;
 255
 256 #undef ASM_OUTPUT_COMMON
 257 #undef ASM_OUTPUT_LOCAL
 258 #define ASM_OUTPUT_COMMON(FILE, NAME, SIZE, ROUNDED)  \
 259 ( fputs (".comm ", (FILE)),                     \
 260   assemble_name ((FILE), (NAME)),               \
 261   fprintf ((FILE), ",%u\n", (SIZE)))
 262
 263 #define ASM_OUTPUT_LOCAL(FILE, NAME, SIZE, ROUNDED)  \
 264 ( fputs (".lcomm ", (FILE)),                    \
 265   assemble_name ((FILE), (NAME)),               \
 266   fprintf ((FILE), ",%u\n", (SIZE)))
 267
 268 /* Override the definition in svr4.h. In m68k svr4, using swbeg is the
 269    standard way to do switch table.  */
 270 #undef ASM_OUTPUT_BEFORE_CASE_LABEL
 271 #define ASM_OUTPUT_BEFORE_CASE_LABEL(FILE,PREFIX,NUM,TABLE)             \
 272   fprintf ((FILE), "%s&%d\n", SWBEG_ASM_OP, XVECLEN (PATTERN (TABLE), 1));
 273
 274 /* In m68k svr4, a symbol_ref rtx can be a valid PIC operand if it is an
 275    operand of a function call.  */
 276 #undef LEGITIMATE_PIC_OPERAND_P
 277 #define LEGITIMATE_PIC_OPERAND_P(X) \
 278   ((! symbolic_operand (X, VOIDmode) \
 279     && ! (GET_CODE (X) == CONST_DOUBLE && mem_for_const_double (X) != 0 \
 280           && GET_CODE (mem_for_const_double (X)) == MEM                 \
 281           && symbolic_operand (XEXP (mem_for_const_double (X), 0),      \
 282                                VOIDmode)))                              \
 283    || (GET_CODE (X) == SYMBOL_REF && SYMBOL_REF_FLAG (X))               \
 284    || PCREL_GENERAL_OPERAND_OK)
 285
 286 /* Output assembler code for a block containing the constant parts
 287    of a trampoline, leaving space for the variable parts.  */
 288
 289 /* On m68k svr4, the trampoline is different from the generic version
 290    in that we use a1 as the static call chain.  */
 291
 292 #undef TRAMPOLINE_TEMPLATE
 293 #define TRAMPOLINE_TEMPLATE(FILE)                                       \
 294 {                                                                       \
 295   assemble_aligned_integer (2, GEN_INT (0x227a));                       \
 296   assemble_aligned_integer (2, GEN_INT (8));                            \
 297   assemble_aligned_integer (2, GEN_INT (0x2f3a));                       \
 298   assemble_aligned_integer (2, GEN_INT (8));                            \
 299   assemble_aligned_integer (2, GEN_INT (0x4e75));                       \
 300   assemble_aligned_integer (4, const0_rtx);                             \
 301   assemble_aligned_integer (4, const0_rtx);                             \
 302 }
 303
 304 /* Redefine since we are using a different trampoline */
 305 #undef TRAMPOLINE_SIZE
 306 #define TRAMPOLINE_SIZE 18
 307
 308 /* Emit RTL insns to initialize the variable parts of a trampoline.
 309    FNADDR is an RTX for the address of the function's pure code.
 310    CXT is an RTX for the static chain value for the function.  */
 311
 312 #undef INITIALIZE_TRAMPOLINE
 313 #define INITIALIZE_TRAMPOLINE(TRAMP, FNADDR, CXT)                       \
 314 {                                                                       \
 315   emit_move_insn (gen_rtx_MEM (SImode, plus_constant (TRAMP, 10)), CXT); \
 316   emit_move_insn (gen_rtx_MEM (SImode, plus_constant (TRAMP, 14)), FNADDR); \
 317 }