gcc/target.h

   1 /* Data structure definitions for a generic GCC target.
   2    Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
   3    2011, 2012
   4    Free Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published by the
   8    Free Software Foundation; either version 3, or (at your option) any
   9    later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; see the file COPYING3.  If not see
  18    <http://www.gnu.org/licenses/>.
  19
  20    In other words, you are welcome to use, share and improve this program.
  21    You are forbidden to forbid anyone else to use, share and improve
  22    what you give them.   Help stamp out software-hoarding!  */
  23
  24
  25 /* This file contains a data structure that describes a GCC target.
  26    At present it is incomplete, but in future it should grow to
  27    contain most or all target machine and target O/S specific
  28    information.
  29
  30    This structure has its initializer declared in target-def.h in the
  31    form of large macro TARGET_INITIALIZER that expands to many smaller
  32    macros.
  33
  34    The smaller macros each initialize one component of the structure,
  35    and each has a default.  Each target should have a file that
  36    includes target.h and target-def.h, and overrides any inappropriate
  37    defaults by undefining the relevant macro and defining a suitable
  38    replacement.  That file should then contain the definition of
  39    "targetm" like so:
  40
  41    struct gcc_target targetm = TARGET_INITIALIZER;
  42
  43    Doing things this way allows us to bring together everything that
  44    defines a GCC target.  By supplying a default that is appropriate
  45    to most targets, we can easily add new items without needing to
  46    edit dozens of target configuration files.  It should also allow us
  47    to gradually reduce the amount of conditional compilation that is
  48    scattered throughout GCC.  */
  49
  50 #ifndef GCC_TARGET_H
  51 #define GCC_TARGET_H
  52
  53 #include "insn-modes.h"
  54
  55 #ifdef ENABLE_CHECKING
  56
  57 typedef struct { void *magic; void *p; } cumulative_args_t;
  58
  59 #else /* !ENABLE_CHECKING */
  60
  61 /* When using a GCC build compiler, we could use
  62    __attribute__((transparent_union)) to get cumulative_args_t function
  63    arguments passed like scalars where the ABI would mandate a less
  64    efficient way of argument passing otherwise.  However, that would come
  65    at the cost of less type-safe !ENABLE_CHECKING compilation.  */
  66
  67 typedef union { void *p; } cumulative_args_t;
  68
  69 #endif /* !ENABLE_CHECKING */
  70
  71 /* Types used by the record_gcc_switches() target function.  */
  72 typedef enum
  73 {
  74   SWITCH_TYPE_PASSED,           /* A switch passed on the command line.  */
  75   SWITCH_TYPE_ENABLED,          /* An option that is currently enabled.  */
  76   SWITCH_TYPE_DESCRIPTIVE,      /* Descriptive text, not a switch or option.  */
  77   SWITCH_TYPE_LINE_START,       /* Please emit any necessary text at the start of a line.  */
  78   SWITCH_TYPE_LINE_END          /* Please emit a line terminator.  */
  79 }
  80 print_switch_type;
  81
  82 typedef int (* print_switch_fn_type) (print_switch_type, const char *);
  83
  84 /* An example implementation for ELF targets.  Defined in varasm.c  */
  85 extern int elf_record_gcc_switches (print_switch_type type, const char *);
  86
  87 /* Some places still assume that all pointer or address modes are the
  88    standard Pmode and ptr_mode.  These optimizations become invalid if
  89    the target actually supports multiple different modes.  For now,
  90    we disable such optimizations on such targets, using this function.  */
  91 extern bool target_default_pointer_address_modes_p (void);
  92
  93 struct stdarg_info;
  94 struct spec_info_def;
  95 struct hard_reg_set_container;
  96
  97 /* The struct used by the secondary_reload target hook.  */
  98 typedef struct secondary_reload_info
  99 {
 100   /* icode is actually an enum insn_code, but we don't want to force every
 101      file that includes target.h to include optabs.h .  */
 102   int icode;
 103   int extra_cost; /* Cost for using (a) scratch register(s) to be taken
 104                      into account by copy_cost.  */
 105   /* The next two members are for the use of the backward
 106      compatibility hook.  */
 107   struct secondary_reload_info *prev_sri;
 108   int t_icode; /* Actually an enum insn_code - see above.  */
 109 } secondary_reload_info;
 110
 111 /* This is defined in sched-int.h .  */
 112 struct _dep;
 113
 114 /* This is defined in ddg.h .  */
 115 struct ddg;
 116
 117 /* This is defined in cfgloop.h .  */
 118 struct loop;
 119
 120 /* This is defined in tree-ssa-alias.h.  */
 121 struct ao_ref_s;
 122
 123 /* This is defined in tree-vectorizer.h.  */
 124 struct _stmt_vec_info;
 125
 126 /* These are defined in tree-vect-stmts.c.  */
 127 extern tree stmt_vectype (struct _stmt_vec_info *);
 128 extern bool stmt_in_inner_loop_p (struct _stmt_vec_info *);
 129
 130 /* Assembler instructions for creating various kinds of integer object.  */
 131
 132 struct asm_int_op
 133 {
 134   const char *hi;
 135   const char *si;
 136   const char *di;
 137   const char *ti;
 138 };
 139
 140 /* Types of costs for vectorizer cost model.  */
 141 enum vect_cost_for_stmt
 142 {
 143   scalar_stmt,
 144   scalar_load,
 145   scalar_store,
 146   vector_stmt,
 147   vector_load,
 148   unaligned_load,
 149   unaligned_store,
 150   vector_store,
 151   vec_to_scalar,
 152   scalar_to_vec,
 153   cond_branch_not_taken,
 154   cond_branch_taken,
 155   vec_perm,
 156   vec_promote_demote,
 157   vec_construct
 158 };
 159
 160 /* Separate locations for which the vectorizer cost model should
 161    track costs.  */
 162 enum vect_cost_model_location {
 163   vect_prologue = 0,
 164   vect_body = 1,
 165   vect_epilogue = 2
 166 };
 167
 168 /* The target structure.  This holds all the backend hooks.  */
 169 #define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
 170 #define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
 171 #define DEFHOOK_UNDOC DEFHOOK
 172 #define HOOKSTRUCT(FRAGMENT) FRAGMENT
 173
 174 #include "target.def"
 175
 176 extern struct gcc_target targetm;
 177
 178 #ifdef GCC_TM_H
 179
 180 #ifndef CUMULATIVE_ARGS_MAGIC
 181 #define CUMULATIVE_ARGS_MAGIC ((void *) &targetm.calls)
 182 #endif
 183
 184 static inline CUMULATIVE_ARGS *
 185 get_cumulative_args (cumulative_args_t arg)
 186 {
 187 #ifdef ENABLE_CHECKING
 188   gcc_assert (arg.magic == CUMULATIVE_ARGS_MAGIC);
 189 #endif /* ENABLE_CHECKING */
 190   return (CUMULATIVE_ARGS *) arg.p;
 191 }
 192
 193 static inline cumulative_args_t
 194 pack_cumulative_args (CUMULATIVE_ARGS *arg)
 195 {
 196   cumulative_args_t ret;
 197
 198 #ifdef ENABLE_CHECKING
 199   ret.magic = CUMULATIVE_ARGS_MAGIC;
 200 #endif /* ENABLE_CHECKING */
 201   ret.p = (void *) arg;
 202   return ret;
 203 }
 204 #endif /* GCC_TM_H */
 205
 206 #endif /* GCC_TARGET_H */