gcc/target.h

   1 /* Data structure definitions for a generic GCC target.
   2    Copyright (C) 2001-2016 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-codes.h"
  52 #include "tm.h"
  53 #include "hard-reg-set.h"
  54
  55 #if CHECKING_P
  56
  57 struct cumulative_args_t { void *magic; void *p; };
  58
  59 #else /* !CHECKING_P */
  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 !CHECKING_P compilation.  */
  66
  67 union cumulative_args_t { void *p; };
  68
  69 #endif /* !CHECKING_P */
  70
  71 /* Types used by the record_gcc_switches() target function.  */
  72 enum print_switch_type
  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
  81 /* Types of memory operation understood by the "by_pieces" infrastructure.
  82    Used by the TARGET_USE_BY_PIECES_INFRASTRUCTURE_P target hook.  */
  83
  84 enum by_pieces_operation
  85 {
  86   CLEAR_BY_PIECES,
  87   MOVE_BY_PIECES,
  88   SET_BY_PIECES,
  89   STORE_BY_PIECES
  90 };
  91
  92 typedef int (* print_switch_fn_type) (print_switch_type, const char *);
  93
  94 /* An example implementation for ELF targets.  Defined in varasm.c  */
  95 extern int elf_record_gcc_switches (print_switch_type type, const char *);
  96
  97 /* Some places still assume that all pointer or address modes are the
  98    standard Pmode and ptr_mode.  These optimizations become invalid if
  99    the target actually supports multiple different modes.  For now,
 100    we disable such optimizations on such targets, using this function.  */
 101 extern bool target_default_pointer_address_modes_p (void);
 102
 103 /* For hooks which use the MOVE_RATIO macro, this gives the legacy default
 104    behavior.  */
 105 extern unsigned int get_move_ratio (bool);
 106
 107 struct stdarg_info;
 108 struct spec_info_def;
 109 struct hard_reg_set_container;
 110 struct cgraph_node;
 111 struct cgraph_simd_clone;
 112
 113 /* The struct used by the secondary_reload target hook.  */
 114 struct secondary_reload_info
 115 {
 116   /* icode is actually an enum insn_code, but we don't want to force every
 117      file that includes target.h to include optabs.h .  */
 118   int icode;
 119   int extra_cost; /* Cost for using (a) scratch register(s) to be taken
 120                      into account by copy_cost.  */
 121   /* The next two members are for the use of the backward
 122      compatibility hook.  */
 123   struct secondary_reload_info *prev_sri;
 124   int t_icode; /* Actually an enum insn_code - see above.  */
 125 };
 126
 127 /* This is defined in sched-int.h .  */
 128 struct _dep;
 129
 130 /* This is defined in ddg.h .  */
 131 struct ddg;
 132
 133 /* This is defined in cfgloop.h .  */
 134 struct loop;
 135
 136 /* This is defined in tree-ssa-alias.h.  */
 137 struct ao_ref;
 138
 139 /* This is defined in tree-vectorizer.h.  */
 140 struct _stmt_vec_info;
 141
 142 /* These are defined in tree-vect-stmts.c.  */
 143 extern tree stmt_vectype (struct _stmt_vec_info *);
 144 extern bool stmt_in_inner_loop_p (struct _stmt_vec_info *);
 145
 146 /* Assembler instructions for creating various kinds of integer object.  */
 147
 148 struct asm_int_op
 149 {
 150   const char *hi;
 151   const char *si;
 152   const char *di;
 153   const char *ti;
 154 };
 155
 156 /* Types of costs for vectorizer cost model.  */
 157 enum vect_cost_for_stmt
 158 {
 159   scalar_stmt,
 160   scalar_load,
 161   scalar_store,
 162   vector_stmt,
 163   vector_load,
 164   unaligned_load,
 165   unaligned_store,
 166   vector_store,
 167   vec_to_scalar,
 168   scalar_to_vec,
 169   cond_branch_not_taken,
 170   cond_branch_taken,
 171   vec_perm,
 172   vec_promote_demote,
 173   vec_construct
 174 };
 175
 176 /* Separate locations for which the vectorizer cost model should
 177    track costs.  */
 178 enum vect_cost_model_location {
 179   vect_prologue = 0,
 180   vect_body = 1,
 181   vect_epilogue = 2
 182 };
 183
 184 /* The target structure.  This holds all the backend hooks.  */
 185 #define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
 186 #define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
 187 #define DEFHOOK_UNDOC DEFHOOK
 188 #define HOOKSTRUCT(FRAGMENT) FRAGMENT
 189
 190 #include "target.def"
 191
 192 extern struct gcc_target targetm;
 193
 194 #ifdef GCC_TM_H
 195
 196 #ifndef CUMULATIVE_ARGS_MAGIC
 197 #define CUMULATIVE_ARGS_MAGIC ((void *) &targetm.calls)
 198 #endif
 199
 200 static inline CUMULATIVE_ARGS *
 201 get_cumulative_args (cumulative_args_t arg)
 202 {
 203 #if CHECKING_P
 204   gcc_assert (arg.magic == CUMULATIVE_ARGS_MAGIC);
 205 #endif /* CHECKING_P */
 206   return (CUMULATIVE_ARGS *) arg.p;
 207 }
 208
 209 static inline cumulative_args_t
 210 pack_cumulative_args (CUMULATIVE_ARGS *arg)
 211 {
 212   cumulative_args_t ret;
 213
 214 #if CHECKING_P
 215   ret.magic = CUMULATIVE_ARGS_MAGIC;
 216 #endif /* CHECKING_P */
 217   ret.p = (void *) arg;
 218   return ret;
 219 }
 220 #endif /* GCC_TM_H */
 221
 222 #endif /* GCC_TARGET_H */