gcc/target.h

   1 /* Data structure definitions for a generic GCC target.
   2    Copyright (C) 2001-2022 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 #include "tree-core.h"
  55
  56 #if CHECKING_P
  57
  58 struct cumulative_args_t { void *magic; void *p; };
  59
  60 #else /* !CHECKING_P */
  61
  62 /* When using a GCC build compiler, we could use
  63    __attribute__((transparent_union)) to get cumulative_args_t function
  64    arguments passed like scalars where the ABI would mandate a less
  65    efficient way of argument passing otherwise.  However, that would come
  66    at the cost of less type-safe !CHECKING_P compilation.  */
  67
  68 union cumulative_args_t { void *p; };
  69
  70 #endif /* !CHECKING_P */
  71
  72 /* Types of memory operation understood by the "by_pieces" infrastructure.
  73    Used by the TARGET_USE_BY_PIECES_INFRASTRUCTURE_P target hook and
  74    internally by the functions in expr.cc.  */
  75
  76 enum by_pieces_operation
  77 {
  78   CLEAR_BY_PIECES,
  79   MOVE_BY_PIECES,
  80   SET_BY_PIECES,
  81   STORE_BY_PIECES,
  82   COMPARE_BY_PIECES
  83 };
  84
  85 extern unsigned HOST_WIDE_INT by_pieces_ninsns (unsigned HOST_WIDE_INT,
  86                                                 unsigned int,
  87                                                 unsigned int,
  88                                                 by_pieces_operation);
  89
  90 /* An example implementation for ELF targets.  Defined in varasm.cc  */
  91 extern void elf_record_gcc_switches (const char *);
  92
  93 /* Some places still assume that all pointer or address modes are the
  94    standard Pmode and ptr_mode.  These optimizations become invalid if
  95    the target actually supports multiple different modes.  For now,
  96    we disable such optimizations on such targets, using this function.  */
  97 extern bool target_default_pointer_address_modes_p (void);
  98
  99 /* For hooks which use the MOVE_RATIO macro, this gives the legacy default
 100    behavior.  */
 101 extern unsigned int get_move_ratio (bool);
 102
 103 struct stdarg_info;
 104 struct spec_info_def;
 105 struct hard_reg_set_container;
 106 struct cgraph_node;
 107 struct cgraph_simd_clone;
 108
 109 /* The struct used by the secondary_reload target hook.  */
 110 struct secondary_reload_info
 111 {
 112   /* icode is actually an enum insn_code, but we don't want to force every
 113      file that includes target.h to include optabs.h .  */
 114   int icode;
 115   int extra_cost; /* Cost for using (a) scratch register(s) to be taken
 116                      into account by copy_cost.  */
 117   /* The next two members are for the use of the backward
 118      compatibility hook.  */
 119   struct secondary_reload_info *prev_sri;
 120   int t_icode; /* Actually an enum insn_code - see above.  */
 121 };
 122
 123 /* This is defined in sched-int.h .  */
 124 struct _dep;
 125
 126 /* This is defined in ddg.h .  */
 127 struct ddg;
 128
 129 /* This is defined in cfgloop.h .  */
 130 class loop;
 131
 132 /* This is defined in ifcvt.h.  */
 133 struct noce_if_info;
 134
 135 /* This is defined in tree-ssa-alias.h.  */
 136 class ao_ref;
 137
 138 /* This is defined in tree-vectorizer.h.  */
 139 class _stmt_vec_info;
 140
 141 /* This is defined in calls.h.  */
 142 class function_arg_info;
 143
 144 /* This is defined in function-abi.h.  */
 145 class predefined_function_abi;
 146
 147 /* These are defined in tree-vect-stmts.cc.  */
 148 extern tree stmt_vectype (class _stmt_vec_info *);
 149 extern bool stmt_in_inner_loop_p (class vec_info *, class _stmt_vec_info *);
 150
 151 /* Assembler instructions for creating various kinds of integer object.  */
 152
 153 struct asm_int_op
 154 {
 155   const char *hi;
 156   const char *psi;
 157   const char *si;
 158   const char *pdi;
 159   const char *di;
 160   const char *pti;
 161   const char *ti;
 162 };
 163
 164 /* Types of costs for vectorizer cost model.  */
 165 enum vect_cost_for_stmt
 166 {
 167   scalar_stmt,
 168   scalar_load,
 169   scalar_store,
 170   vector_stmt,
 171   vector_load,
 172   vector_gather_load,
 173   unaligned_load,
 174   unaligned_store,
 175   vector_store,
 176   vector_scatter_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 class vec_perm_indices;
 195
 196 /* The type to use for lists of vector sizes.  */
 197 typedef vec<machine_mode> vector_modes;
 198
 199 /* Same, but can be used to construct local lists that are
 200    automatically freed.  */
 201 typedef auto_vec<machine_mode, 8> auto_vector_modes;
 202
 203 /* First argument of targetm.omp.device_kind_arch_isa.  */
 204 enum omp_device_kind_arch_isa {
 205   omp_device_kind,
 206   omp_device_arch,
 207   omp_device_isa
 208 };
 209
 210 /* Flags returned by TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES:
 211
 212    VECT_COMPARE_COSTS
 213        Tells the loop vectorizer to try all the provided modes and
 214        pick the one with the lowest cost.  By default the vectorizer
 215        will choose the first mode that works.  */
 216 const unsigned int VECT_COMPARE_COSTS = 1U << 0;
 217
 218 /* The contexts in which the use of a type T can be checked by
 219    TARGET_VERIFY_TYPE_CONTEXT.  */
 220 enum type_context_kind {
 221   /* Directly measuring the size of T.  */
 222   TCTX_SIZEOF,
 223
 224   /* Directly measuring the alignment of T.  */
 225   TCTX_ALIGNOF,
 226
 227   /* Creating objects of type T with static storage duration.  */
 228   TCTX_STATIC_STORAGE,
 229
 230   /* Creating objects of type T with thread-local storage duration.  */
 231   TCTX_THREAD_STORAGE,
 232
 233   /* Creating a field of type T.  */
 234   TCTX_FIELD,
 235
 236   /* Creating an array with elements of type T.  */
 237   TCTX_ARRAY_ELEMENT,
 238
 239   /* Adding to or subtracting from a pointer to T, or computing the
 240      difference between two pointers when one of them is a pointer to T.  */
 241   TCTX_POINTER_ARITH,
 242
 243   /* Dynamically allocating objects of type T.  */
 244   TCTX_ALLOCATION,
 245
 246   /* Dynamically deallocating objects of type T.  */
 247   TCTX_DEALLOCATION,
 248
 249   /* Throwing or catching an object of type T.  */
 250   TCTX_EXCEPTIONS,
 251
 252   /* Capturing objects of type T by value in a closure.  */
 253   TCTX_CAPTURE_BY_COPY
 254 };
 255
 256 enum poly_value_estimate_kind
 257 {
 258   POLY_VALUE_MIN,
 259   POLY_VALUE_MAX,
 260   POLY_VALUE_LIKELY
 261 };
 262
 263 extern bool verify_type_context (location_t, type_context_kind, const_tree,
 264                                  bool = false);
 265
 266 /* The target structure.  This holds all the backend hooks.  */
 267 #define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
 268 #define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
 269 #define DEFHOOK_UNDOC DEFHOOK
 270 #define HOOKSTRUCT(FRAGMENT) FRAGMENT
 271
 272 #include "target.def"
 273
 274 extern struct gcc_target targetm;
 275
 276 /* Return an estimate of the runtime value of X, for use in things
 277    like cost calculations or profiling frequencies.  Note that this
 278    function should never be used in situations where the actual
 279    runtime value is needed for correctness, since the function only
 280    provides a rough guess.  */
 281
 282 static inline HOST_WIDE_INT
 283 estimated_poly_value (poly_int64 x,
 284                       poly_value_estimate_kind kind = POLY_VALUE_LIKELY)
 285 {
 286   if (NUM_POLY_INT_COEFFS == 1)
 287     return x.coeffs[0];
 288   else
 289     return targetm.estimated_poly_value (x, kind);
 290 }
 291
 292 #ifdef GCC_TM_H
 293
 294 #ifndef CUMULATIVE_ARGS_MAGIC
 295 #define CUMULATIVE_ARGS_MAGIC ((void *) &targetm.calls)
 296 #endif
 297
 298 static inline CUMULATIVE_ARGS *
 299 get_cumulative_args (cumulative_args_t arg)
 300 {
 301 #if CHECKING_P
 302   gcc_assert (arg.magic == CUMULATIVE_ARGS_MAGIC);
 303 #endif /* CHECKING_P */
 304   return (CUMULATIVE_ARGS *) arg.p;
 305 }
 306
 307 static inline cumulative_args_t
 308 pack_cumulative_args (CUMULATIVE_ARGS *arg)
 309 {
 310   cumulative_args_t ret;
 311
 312 #if CHECKING_P
 313   ret.magic = CUMULATIVE_ARGS_MAGIC;
 314 #endif /* CHECKING_P */
 315   ret.p = (void *) arg;
 316   return ret;
 317 }
 318 #endif /* GCC_TM_H */
 319
 320 #endif /* GCC_TARGET_H */