gcc/target.h

   1 /* Data structure definitions for a generic GCC target.
   2    Copyright (C) 2001-2017 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 and
  83    internally by the functions in expr.c.  */
  84
  85 enum by_pieces_operation
  86 {
  87   CLEAR_BY_PIECES,
  88   MOVE_BY_PIECES,
  89   SET_BY_PIECES,
  90   STORE_BY_PIECES,
  91   COMPARE_BY_PIECES
  92 };
  93
  94 extern unsigned HOST_WIDE_INT by_pieces_ninsns (unsigned HOST_WIDE_INT,
  95                                                 unsigned int,
  96                                                 unsigned int,
  97                                                 by_pieces_operation);
  98
  99 typedef int (* print_switch_fn_type) (print_switch_type, const char *);
 100
 101 /* An example implementation for ELF targets.  Defined in varasm.c  */
 102 extern int elf_record_gcc_switches (print_switch_type type, const char *);
 103
 104 /* Some places still assume that all pointer or address modes are the
 105    standard Pmode and ptr_mode.  These optimizations become invalid if
 106    the target actually supports multiple different modes.  For now,
 107    we disable such optimizations on such targets, using this function.  */
 108 extern bool target_default_pointer_address_modes_p (void);
 109
 110 /* For hooks which use the MOVE_RATIO macro, this gives the legacy default
 111    behavior.  */
 112 extern unsigned int get_move_ratio (bool);
 113
 114 struct stdarg_info;
 115 struct spec_info_def;
 116 struct hard_reg_set_container;
 117 struct cgraph_node;
 118 struct cgraph_simd_clone;
 119
 120 /* The struct used by the secondary_reload target hook.  */
 121 struct secondary_reload_info
 122 {
 123   /* icode is actually an enum insn_code, but we don't want to force every
 124      file that includes target.h to include optabs.h .  */
 125   int icode;
 126   int extra_cost; /* Cost for using (a) scratch register(s) to be taken
 127                      into account by copy_cost.  */
 128   /* The next two members are for the use of the backward
 129      compatibility hook.  */
 130   struct secondary_reload_info *prev_sri;
 131   int t_icode; /* Actually an enum insn_code - see above.  */
 132 };
 133
 134 /* This is defined in sched-int.h .  */
 135 struct _dep;
 136
 137 /* This is defined in ddg.h .  */
 138 struct ddg;
 139
 140 /* This is defined in cfgloop.h .  */
 141 struct loop;
 142
 143 /* This is defined in ifcvt.h.  */
 144 struct noce_if_info;
 145
 146 /* This is defined in tree-ssa-alias.h.  */
 147 struct ao_ref;
 148
 149 /* This is defined in tree-vectorizer.h.  */
 150 struct _stmt_vec_info;
 151
 152 /* These are defined in tree-vect-stmts.c.  */
 153 extern tree stmt_vectype (struct _stmt_vec_info *);
 154 extern bool stmt_in_inner_loop_p (struct _stmt_vec_info *);
 155
 156 /* Assembler instructions for creating various kinds of integer object.  */
 157
 158 struct asm_int_op
 159 {
 160   const char *hi;
 161   const char *si;
 162   const char *di;
 163   const char *ti;
 164 };
 165
 166 /* Types of costs for vectorizer cost model.  */
 167 enum vect_cost_for_stmt
 168 {
 169   scalar_stmt,
 170   scalar_load,
 171   scalar_store,
 172   vector_stmt,
 173   vector_load,
 174   unaligned_load,
 175   unaligned_store,
 176   vector_store,
 177   vec_to_scalar,
 178   scalar_to_vec,
 179   cond_branch_not_taken,
 180   cond_branch_taken,
 181   vec_perm,
 182   vec_promote_demote,
 183   vec_construct
 184 };
 185
 186 /* Separate locations for which the vectorizer cost model should
 187    track costs.  */
 188 enum vect_cost_model_location {
 189   vect_prologue = 0,
 190   vect_body = 1,
 191   vect_epilogue = 2
 192 };
 193
 194 /* The target structure.  This holds all the backend hooks.  */
 195 #define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
 196 #define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
 197 #define DEFHOOK_UNDOC DEFHOOK
 198 #define HOOKSTRUCT(FRAGMENT) FRAGMENT
 199
 200 #include "target.def"
 201
 202 extern struct gcc_target targetm;
 203
 204 #ifdef GCC_TM_H
 205
 206 #ifndef CUMULATIVE_ARGS_MAGIC
 207 #define CUMULATIVE_ARGS_MAGIC ((void *) &targetm.calls)
 208 #endif
 209
 210 static inline CUMULATIVE_ARGS *
 211 get_cumulative_args (cumulative_args_t arg)
 212 {
 213 #if CHECKING_P
 214   gcc_assert (arg.magic == CUMULATIVE_ARGS_MAGIC);
 215 #endif /* CHECKING_P */
 216   return (CUMULATIVE_ARGS *) arg.p;
 217 }
 218
 219 static inline cumulative_args_t
 220 pack_cumulative_args (CUMULATIVE_ARGS *arg)
 221 {
 222   cumulative_args_t ret;
 223
 224 #if CHECKING_P
 225   ret.magic = CUMULATIVE_ARGS_MAGIC;
 226 #endif /* CHECKING_P */
 227   ret.p = (void *) arg;
 228   return ret;
 229 }
 230 #endif /* GCC_TM_H */
 231
 232 #endif /* GCC_TARGET_H */