gcc/target.h

   1 /* Data structure definitions for a generic GCC target.
   2    Copyright (C) 2001-2021 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 of memory operation understood by the "by_pieces" infrastructure.
  72    Used by the TARGET_USE_BY_PIECES_INFRASTRUCTURE_P target hook and
  73    internally by the functions in expr.c.  */
  74
  75 enum by_pieces_operation
  76 {
  77   CLEAR_BY_PIECES,
  78   MOVE_BY_PIECES,
  79   SET_BY_PIECES,
  80   STORE_BY_PIECES,
  81   COMPARE_BY_PIECES
  82 };
  83
  84 extern unsigned HOST_WIDE_INT by_pieces_ninsns (unsigned HOST_WIDE_INT,
  85                                                 unsigned int,
  86                                                 unsigned int,
  87                                                 by_pieces_operation);
  88
  89 /* An example implementation for ELF targets.  Defined in varasm.c  */
  90 extern void elf_record_gcc_switches (const char *);
  91
  92 /* Some places still assume that all pointer or address modes are the
  93    standard Pmode and ptr_mode.  These optimizations become invalid if
  94    the target actually supports multiple different modes.  For now,
  95    we disable such optimizations on such targets, using this function.  */
  96 extern bool target_default_pointer_address_modes_p (void);
  97
  98 /* For hooks which use the MOVE_RATIO macro, this gives the legacy default
  99    behavior.  */
 100 extern unsigned int get_move_ratio (bool);
 101
 102 struct stdarg_info;
 103 struct spec_info_def;
 104 struct hard_reg_set_container;
 105 struct cgraph_node;
 106 struct cgraph_simd_clone;
 107
 108 /* The struct used by the secondary_reload target hook.  */
 109 struct secondary_reload_info
 110 {
 111   /* icode is actually an enum insn_code, but we don't want to force every
 112      file that includes target.h to include optabs.h .  */
 113   int icode;
 114   int extra_cost; /* Cost for using (a) scratch register(s) to be taken
 115                      into account by copy_cost.  */
 116   /* The next two members are for the use of the backward
 117      compatibility hook.  */
 118   struct secondary_reload_info *prev_sri;
 119   int t_icode; /* Actually an enum insn_code - see above.  */
 120 };
 121
 122 /* This is defined in sched-int.h .  */
 123 struct _dep;
 124
 125 /* This is defined in ddg.h .  */
 126 struct ddg;
 127
 128 /* This is defined in cfgloop.h .  */
 129 class loop;
 130
 131 /* This is defined in ifcvt.h.  */
 132 struct noce_if_info;
 133
 134 /* This is defined in tree-ssa-alias.h.  */
 135 class ao_ref;
 136
 137 /* This is defined in tree-vectorizer.h.  */
 138 class _stmt_vec_info;
 139
 140 /* This is defined in calls.h.  */
 141 class function_arg_info;
 142
 143 /* This is defined in function-abi.h.  */
 144 class predefined_function_abi;
 145
 146 /* These are defined in tree-vect-stmts.c.  */
 147 extern tree stmt_vectype (class _stmt_vec_info *);
 148 extern bool stmt_in_inner_loop_p (class vec_info *, class _stmt_vec_info *);
 149
 150 /* Assembler instructions for creating various kinds of integer object.  */
 151
 152 struct asm_int_op
 153 {
 154   const char *hi;
 155   const char *psi;
 156   const char *si;
 157   const char *pdi;
 158   const char *di;
 159   const char *pti;
 160   const char *ti;
 161 };
 162
 163 /* Types of costs for vectorizer cost model.  */
 164 enum vect_cost_for_stmt
 165 {
 166   scalar_stmt,
 167   scalar_load,
 168   scalar_store,
 169   vector_stmt,
 170   vector_load,
 171   vector_gather_load,
 172   unaligned_load,
 173   unaligned_store,
 174   vector_store,
 175   vector_scatter_store,
 176   vec_to_scalar,
 177   scalar_to_vec,
 178   cond_branch_not_taken,
 179   cond_branch_taken,
 180   vec_perm,
 181   vec_promote_demote,
 182   vec_construct
 183 };
 184
 185 /* Separate locations for which the vectorizer cost model should
 186    track costs.  */
 187 enum vect_cost_model_location {
 188   vect_prologue = 0,
 189   vect_body = 1,
 190   vect_epilogue = 2
 191 };
 192
 193 class vec_perm_indices;
 194
 195 /* The type to use for lists of vector sizes.  */
 196 typedef vec<machine_mode> vector_modes;
 197
 198 /* Same, but can be used to construct local lists that are
 199    automatically freed.  */
 200 typedef auto_vec<machine_mode, 8> auto_vector_modes;
 201
 202 /* First argument of targetm.omp.device_kind_arch_isa.  */
 203 enum omp_device_kind_arch_isa {
 204   omp_device_kind,
 205   omp_device_arch,
 206   omp_device_isa
 207 };
 208
 209 /* Flags returned by TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES:
 210
 211    VECT_COMPARE_COSTS
 212        Tells the loop vectorizer to try all the provided modes and
 213        pick the one with the lowest cost.  By default the vectorizer
 214        will choose the first mode that works.  */
 215 const unsigned int VECT_COMPARE_COSTS = 1U << 0;
 216
 217 /* The contexts in which the use of a type T can be checked by
 218    TARGET_VERIFY_TYPE_CONTEXT.  */
 219 enum type_context_kind {
 220   /* Directly measuring the size of T.  */
 221   TCTX_SIZEOF,
 222
 223   /* Directly measuring the alignment of T.  */
 224   TCTX_ALIGNOF,
 225
 226   /* Creating objects of type T with static storage duration.  */
 227   TCTX_STATIC_STORAGE,
 228
 229   /* Creating objects of type T with thread-local storage duration.  */
 230   TCTX_THREAD_STORAGE,
 231
 232   /* Creating a field of type T.  */
 233   TCTX_FIELD,
 234
 235   /* Creating an array with elements of type T.  */
 236   TCTX_ARRAY_ELEMENT,
 237
 238   /* Adding to or subtracting from a pointer to T, or computing the
 239      difference between two pointers when one of them is a pointer to T.  */
 240   TCTX_POINTER_ARITH,
 241
 242   /* Dynamically allocating objects of type T.  */
 243   TCTX_ALLOCATION,
 244
 245   /* Dynamically deallocating objects of type T.  */
 246   TCTX_DEALLOCATION,
 247
 248   /* Throwing or catching an object of type T.  */
 249   TCTX_EXCEPTIONS,
 250
 251   /* Capturing objects of type T by value in a closure.  */
 252   TCTX_CAPTURE_BY_COPY
 253 };
 254
 255 enum poly_value_estimate_kind
 256 {
 257   POLY_VALUE_MIN,
 258   POLY_VALUE_MAX,
 259   POLY_VALUE_LIKELY
 260 };
 261
 262 extern bool verify_type_context (location_t, type_context_kind, const_tree,
 263                                  bool = false);
 264
 265 /* The target structure.  This holds all the backend hooks.  */
 266 #define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
 267 #define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
 268 #define DEFHOOK_UNDOC DEFHOOK
 269 #define HOOKSTRUCT(FRAGMENT) FRAGMENT
 270
 271 #include "target.def"
 272
 273 extern struct gcc_target targetm;
 274
 275 /* Return an estimate of the runtime value of X, for use in things
 276    like cost calculations or profiling frequencies.  Note that this
 277    function should never be used in situations where the actual
 278    runtime value is needed for correctness, since the function only
 279    provides a rough guess.  */
 280
 281 static inline HOST_WIDE_INT
 282 estimated_poly_value (poly_int64 x,
 283                       poly_value_estimate_kind kind = POLY_VALUE_LIKELY)
 284 {
 285   if (NUM_POLY_INT_COEFFS == 1)
 286     return x.coeffs[0];
 287   else
 288     return targetm.estimated_poly_value (x, kind);
 289 }
 290
 291 #ifdef GCC_TM_H
 292
 293 #ifndef CUMULATIVE_ARGS_MAGIC
 294 #define CUMULATIVE_ARGS_MAGIC ((void *) &targetm.calls)
 295 #endif
 296
 297 static inline CUMULATIVE_ARGS *
 298 get_cumulative_args (cumulative_args_t arg)
 299 {
 300 #if CHECKING_P
 301   gcc_assert (arg.magic == CUMULATIVE_ARGS_MAGIC);
 302 #endif /* CHECKING_P */
 303   return (CUMULATIVE_ARGS *) arg.p;
 304 }
 305
 306 static inline cumulative_args_t
 307 pack_cumulative_args (CUMULATIVE_ARGS *arg)
 308 {
 309   cumulative_args_t ret;
 310
 311 #if CHECKING_P
 312   ret.magic = CUMULATIVE_ARGS_MAGIC;
 313 #endif /* CHECKING_P */
 314   ret.p = (void *) arg;
 315   return ret;
 316 }
 317 #endif /* GCC_TM_H */
 318
 319 #endif /* GCC_TARGET_H */