gcc/target.h

   1 /* Data structure definitions for a generic GCC target.
   2    Copyright (C) 2001-2014 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify it
   5    under the terms of the GNU General Public License as published by the
   6    Free Software Foundation; either version 3, or (at your option) any
   7    later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; see the file COPYING3.  If not see
  16    <http://www.gnu.org/licenses/>.
  17
  18    In other words, you are welcome to use, share and improve this program.
  19    You are forbidden to forbid anyone else to use, share and improve
  20    what you give them.   Help stamp out software-hoarding!  */
  21
  22
  23 /* This file contains a data structure that describes a GCC target.
  24    At present it is incomplete, but in future it should grow to
  25    contain most or all target machine and target O/S specific
  26    information.
  27
  28    This structure has its initializer declared in target-def.h in the
  29    form of large macro TARGET_INITIALIZER that expands to many smaller
  30    macros.
  31
  32    The smaller macros each initialize one component of the structure,
  33    and each has a default.  Each target should have a file that
  34    includes target.h and target-def.h, and overrides any inappropriate
  35    defaults by undefining the relevant macro and defining a suitable
  36    replacement.  That file should then contain the definition of
  37    "targetm" like so:
  38
  39    struct gcc_target targetm = TARGET_INITIALIZER;
  40
  41    Doing things this way allows us to bring together everything that
  42    defines a GCC target.  By supplying a default that is appropriate
  43    to most targets, we can easily add new items without needing to
  44    edit dozens of target configuration files.  It should also allow us
  45    to gradually reduce the amount of conditional compilation that is
  46    scattered throughout GCC.  */
  47
  48 #ifndef GCC_TARGET_H
  49 #define GCC_TARGET_H
  50
  51 #include "insn-modes.h"
  52 #include "insn-codes.h"
  53 #include "wide-int.h"
  54 #include "tm.h"
  55 #include "hard-reg-set.h"
  56
  57 #ifdef ENABLE_CHECKING
  58
  59 struct cumulative_args_t { void *magic; void *p; };
  60
  61 #else /* !ENABLE_CHECKING */
  62
  63 /* When using a GCC build compiler, we could use
  64    __attribute__((transparent_union)) to get cumulative_args_t function
  65    arguments passed like scalars where the ABI would mandate a less
  66    efficient way of argument passing otherwise.  However, that would come
  67    at the cost of less type-safe !ENABLE_CHECKING compilation.  */
  68
  69 union cumulative_args_t { void *p; };
  70
  71 #endif /* !ENABLE_CHECKING */
  72
  73 /* Types used by the record_gcc_switches() target function.  */
  74 enum print_switch_type
  75 {
  76   SWITCH_TYPE_PASSED,           /* A switch passed on the command line.  */
  77   SWITCH_TYPE_ENABLED,          /* An option that is currently enabled.  */
  78   SWITCH_TYPE_DESCRIPTIVE,      /* Descriptive text, not a switch or option.  */
  79   SWITCH_TYPE_LINE_START,       /* Please emit any necessary text at the start of a line.  */
  80   SWITCH_TYPE_LINE_END          /* Please emit a line terminator.  */
  81 };
  82
  83 /* Types of memory operation understood by the "by_pieces" infrastructure.
  84    Used by the TARGET_USE_BY_PIECES_INFRASTRUCTURE_P target hook.  */
  85
  86 enum by_pieces_operation
  87 {
  88   CLEAR_BY_PIECES,
  89   MOVE_BY_PIECES,
  90   SET_BY_PIECES,
  91   STORE_BY_PIECES
  92 };
  93
  94 typedef int (* print_switch_fn_type) (print_switch_type, const char *);
  95
  96 /* An example implementation for ELF targets.  Defined in varasm.c  */
  97 extern int elf_record_gcc_switches (print_switch_type type, const char *);
  98
  99 /* Some places still assume that all pointer or address modes are the
 100    standard Pmode and ptr_mode.  These optimizations become invalid if
 101    the target actually supports multiple different modes.  For now,
 102    we disable such optimizations on such targets, using this function.  */
 103 extern bool target_default_pointer_address_modes_p (void);
 104
 105 /* For hooks which use the MOVE_RATIO macro, this gives the legacy default
 106    behaviour.  */
 107 extern unsigned int get_move_ratio (bool);
 108
 109 struct stdarg_info;
 110 struct spec_info_def;
 111 struct hard_reg_set_container;
 112 struct cgraph_node;
 113 struct cgraph_simd_clone;
 114
 115 /* The struct used by the secondary_reload target hook.  */
 116 struct secondary_reload_info
 117 {
 118   /* icode is actually an enum insn_code, but we don't want to force every
 119      file that includes target.h to include optabs.h .  */
 120   int icode;
 121   int extra_cost; /* Cost for using (a) scratch register(s) to be taken
 122                      into account by copy_cost.  */
 123   /* The next two members are for the use of the backward
 124      compatibility hook.  */
 125   struct secondary_reload_info *prev_sri;
 126   int t_icode; /* Actually an enum insn_code - see above.  */
 127 };
 128
 129 /* This is defined in sched-int.h .  */
 130 struct _dep;
 131
 132 /* This is defined in ddg.h .  */
 133 struct ddg;
 134
 135 /* This is defined in cfgloop.h .  */
 136 struct loop;
 137
 138 /* This is defined in tree-ssa-alias.h.  */
 139 struct ao_ref;
 140
 141 /* This is defined in tree-vectorizer.h.  */
 142 struct _stmt_vec_info;
 143
 144 /* These are defined in tree-vect-stmts.c.  */
 145 extern tree stmt_vectype (struct _stmt_vec_info *);
 146 extern bool stmt_in_inner_loop_p (struct _stmt_vec_info *);
 147
 148 /* Assembler instructions for creating various kinds of integer object.  */
 149
 150 struct asm_int_op
 151 {
 152   const char *hi;
 153   const char *si;
 154   const char *di;
 155   const char *ti;
 156 };
 157
 158 /* Types of costs for vectorizer cost model.  */
 159 enum vect_cost_for_stmt
 160 {
 161   scalar_stmt,
 162   scalar_load,
 163   scalar_store,
 164   vector_stmt,
 165   vector_load,
 166   unaligned_load,
 167   unaligned_store,
 168   vector_store,
 169   vec_to_scalar,
 170   scalar_to_vec,
 171   cond_branch_not_taken,
 172   cond_branch_taken,
 173   vec_perm,
 174   vec_promote_demote,
 175   vec_construct
 176 };
 177
 178 /* Separate locations for which the vectorizer cost model should
 179    track costs.  */
 180 enum vect_cost_model_location {
 181   vect_prologue = 0,
 182   vect_body = 1,
 183   vect_epilogue = 2
 184 };
 185
 186 /* The target structure.  This holds all the backend hooks.  */
 187 #define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
 188 #define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
 189 #define DEFHOOK_UNDOC DEFHOOK
 190 #define HOOKSTRUCT(FRAGMENT) FRAGMENT
 191
 192 #include "target.def"
 193
 194 extern struct gcc_target targetm;
 195
 196 #ifdef GCC_TM_H
 197
 198 #ifndef CUMULATIVE_ARGS_MAGIC
 199 #define CUMULATIVE_ARGS_MAGIC ((void *) &targetm.calls)
 200 #endif
 201
 202 static inline CUMULATIVE_ARGS *
 203 get_cumulative_args (cumulative_args_t arg)
 204 {
 205 #ifdef ENABLE_CHECKING
 206   gcc_assert (arg.magic == CUMULATIVE_ARGS_MAGIC);
 207 #endif /* ENABLE_CHECKING */
 208   return (CUMULATIVE_ARGS *) arg.p;
 209 }
 210
 211 static inline cumulative_args_t
 212 pack_cumulative_args (CUMULATIVE_ARGS *arg)
 213 {
 214   cumulative_args_t ret;
 215
 216 #ifdef ENABLE_CHECKING
 217   ret.magic = CUMULATIVE_ARGS_MAGIC;
 218 #endif /* ENABLE_CHECKING */
 219   ret.p = (void *) arg;
 220   return ret;
 221 }
 222 #endif /* GCC_TM_H */
 223
 224 #endif /* GCC_TARGET_H */