gcc/target.h

   1 /* Data structure definitions for a generic GCC target.
   2    Copyright (C) 2001-2023 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 /* Target properties of _BitInt(N) type.  _BitInt(N) is to be represented
  72    as series of limb_mode CEIL (N, GET_MODE_PRECISION (limb_mode)) limbs,
  73    ordered from least significant to most significant if !big_endian,
  74    otherwise from most significant to least significant.  If extended is
  75    false, the bits above or equal to N are undefined when stored in a register
  76    or memory, otherwise they are zero or sign extended depending on if
  77    it is unsigned _BitInt(N) or _BitInt(N) / signed _BitInt(N).  */
  78
  79 struct bitint_info {
  80   machine_mode limb_mode;
  81   bool big_endian;
  82   bool extended;
  83 };
  84
  85 /* Types of memory operation understood by the "by_pieces" infrastructure.
  86    Used by the TARGET_USE_BY_PIECES_INFRASTRUCTURE_P target hook and
  87    internally by the functions in expr.cc.  */
  88
  89 enum by_pieces_operation
  90 {
  91   CLEAR_BY_PIECES,
  92   MOVE_BY_PIECES,
  93   SET_BY_PIECES,
  94   STORE_BY_PIECES,
  95   COMPARE_BY_PIECES
  96 };
  97
  98 extern unsigned HOST_WIDE_INT by_pieces_ninsns (unsigned HOST_WIDE_INT,
  99                                                 unsigned int,
 100                                                 unsigned int,
 101                                                 by_pieces_operation);
 102
 103 /* An example implementation for ELF targets.  Defined in varasm.cc  */
 104 extern void elf_record_gcc_switches (const char *);
 105
 106 /* Some places still assume that all pointer or address modes are the
 107    standard Pmode and ptr_mode.  These optimizations become invalid if
 108    the target actually supports multiple different modes.  For now,
 109    we disable such optimizations on such targets, using this function.  */
 110 extern bool target_default_pointer_address_modes_p (void);
 111
 112 /* For hooks which use the MOVE_RATIO macro, this gives the legacy default
 113    behavior.  */
 114 extern unsigned int get_move_ratio (bool);
 115
 116 struct stdarg_info;
 117 struct spec_info_def;
 118 struct hard_reg_set_container;
 119 struct cgraph_node;
 120 struct cgraph_simd_clone;
 121
 122 /* The struct used by the secondary_reload target hook.  */
 123 struct secondary_reload_info
 124 {
 125   /* icode is actually an enum insn_code, but we don't want to force every
 126      file that includes target.h to include optabs.h .  */
 127   int icode;
 128   int extra_cost; /* Cost for using (a) scratch register(s) to be taken
 129                      into account by copy_cost.  */
 130   /* The next two members are for the use of the backward
 131      compatibility hook.  */
 132   struct secondary_reload_info *prev_sri;
 133   int t_icode; /* Actually an enum insn_code - see above.  */
 134 };
 135
 136 /* This is defined in sched-int.h .  */
 137 struct _dep;
 138
 139 /* This is defined in ddg.h .  */
 140 struct ddg;
 141
 142 /* This is defined in cfgloop.h .  */
 143 class loop;
 144
 145 /* This is defined in ifcvt.h.  */
 146 struct noce_if_info;
 147
 148 /* This is defined in tree-ssa-alias.h.  */
 149 class ao_ref;
 150
 151 /* This is defined in tree-vectorizer.h.  */
 152 class _stmt_vec_info;
 153
 154 /* This is defined in calls.h.  */
 155 class function_arg_info;
 156
 157 /* This is defined in function-abi.h.  */
 158 class predefined_function_abi;
 159
 160 /* These are defined in tree-vect-stmts.cc.  */
 161 extern tree stmt_vectype (class _stmt_vec_info *);
 162 extern bool stmt_in_inner_loop_p (class vec_info *, class _stmt_vec_info *);
 163
 164 /* Assembler instructions for creating various kinds of integer object.  */
 165
 166 struct asm_int_op
 167 {
 168   const char *hi;
 169   const char *psi;
 170   const char *si;
 171   const char *pdi;
 172   const char *di;
 173   const char *pti;
 174   const char *ti;
 175 };
 176
 177 /* Types of costs for vectorizer cost model.  */
 178 enum vect_cost_for_stmt
 179 {
 180   scalar_stmt,
 181   scalar_load,
 182   scalar_store,
 183   vector_stmt,
 184   vector_load,
 185   vector_gather_load,
 186   unaligned_load,
 187   unaligned_store,
 188   vector_store,
 189   vector_scatter_store,
 190   vec_to_scalar,
 191   scalar_to_vec,
 192   cond_branch_not_taken,
 193   cond_branch_taken,
 194   vec_perm,
 195   vec_promote_demote,
 196   vec_construct
 197 };
 198
 199 /* Separate locations for which the vectorizer cost model should
 200    track costs.  */
 201 enum vect_cost_model_location {
 202   vect_prologue = 0,
 203   vect_body = 1,
 204   vect_epilogue = 2
 205 };
 206
 207 class vec_perm_indices;
 208
 209 /* The type to use for lists of vector sizes.  */
 210 typedef vec<machine_mode> vector_modes;
 211
 212 /* Same, but can be used to construct local lists that are
 213    automatically freed.  */
 214 typedef auto_vec<machine_mode, 8> auto_vector_modes;
 215
 216 /* First argument of targetm.omp.device_kind_arch_isa.  */
 217 enum omp_device_kind_arch_isa {
 218   omp_device_kind,
 219   omp_device_arch,
 220   omp_device_isa
 221 };
 222
 223 /* Flags returned by TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES:
 224
 225    VECT_COMPARE_COSTS
 226        Tells the loop vectorizer to try all the provided modes and
 227        pick the one with the lowest cost.  By default the vectorizer
 228        will choose the first mode that works.  */
 229 const unsigned int VECT_COMPARE_COSTS = 1U << 0;
 230
 231 /* The contexts in which the use of a type T can be checked by
 232    TARGET_VERIFY_TYPE_CONTEXT.  */
 233 enum type_context_kind {
 234   /* Directly measuring the size of T.  */
 235   TCTX_SIZEOF,
 236
 237   /* Directly measuring the alignment of T.  */
 238   TCTX_ALIGNOF,
 239
 240   /* Creating objects of type T with static storage duration.  */
 241   TCTX_STATIC_STORAGE,
 242
 243   /* Creating objects of type T with thread-local storage duration.  */
 244   TCTX_THREAD_STORAGE,
 245
 246   /* Creating a field of type T.  */
 247   TCTX_FIELD,
 248
 249   /* Creating an array with elements of type T.  */
 250   TCTX_ARRAY_ELEMENT,
 251
 252   /* Adding to or subtracting from a pointer to T, or computing the
 253      difference between two pointers when one of them is a pointer to T.  */
 254   TCTX_POINTER_ARITH,
 255
 256   /* Dynamically allocating objects of type T.  */
 257   TCTX_ALLOCATION,
 258
 259   /* Dynamically deallocating objects of type T.  */
 260   TCTX_DEALLOCATION,
 261
 262   /* Throwing or catching an object of type T.  */
 263   TCTX_EXCEPTIONS,
 264
 265   /* Capturing objects of type T by value in a closure.  */
 266   TCTX_CAPTURE_BY_COPY
 267 };
 268
 269 enum poly_value_estimate_kind
 270 {
 271   POLY_VALUE_MIN,
 272   POLY_VALUE_MAX,
 273   POLY_VALUE_LIKELY
 274 };
 275
 276 typedef void (*emit_support_tinfos_callback) (tree);
 277
 278 extern bool verify_type_context (location_t, type_context_kind, const_tree,
 279                                  bool = false);
 280
 281 /* The target structure.  This holds all the backend hooks.  */
 282 #define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
 283 #define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
 284 #define DEFHOOK_UNDOC DEFHOOK
 285 #define HOOKSTRUCT(FRAGMENT) FRAGMENT
 286
 287 #include "target.def"
 288
 289 extern struct gcc_target targetm;
 290
 291 /* Return an estimate of the runtime value of X, for use in things
 292    like cost calculations or profiling frequencies.  Note that this
 293    function should never be used in situations where the actual
 294    runtime value is needed for correctness, since the function only
 295    provides a rough guess.  */
 296
 297 inline HOST_WIDE_INT
 298 estimated_poly_value (poly_int64 x,
 299                       poly_value_estimate_kind kind = POLY_VALUE_LIKELY)
 300 {
 301   if (NUM_POLY_INT_COEFFS == 1)
 302     return x.coeffs[0];
 303   else
 304     return targetm.estimated_poly_value (x, kind);
 305 }
 306
 307 #ifdef GCC_TM_H
 308
 309 #ifndef CUMULATIVE_ARGS_MAGIC
 310 #define CUMULATIVE_ARGS_MAGIC ((void *) &targetm.calls)
 311 #endif
 312
 313 inline CUMULATIVE_ARGS *
 314 get_cumulative_args (cumulative_args_t arg)
 315 {
 316 #if CHECKING_P
 317   gcc_assert (arg.magic == CUMULATIVE_ARGS_MAGIC);
 318 #endif /* CHECKING_P */
 319   return (CUMULATIVE_ARGS *) arg.p;
 320 }
 321
 322 inline cumulative_args_t
 323 pack_cumulative_args (CUMULATIVE_ARGS *arg)
 324 {
 325   cumulative_args_t ret;
 326
 327 #if CHECKING_P
 328   ret.magic = CUMULATIVE_ARGS_MAGIC;
 329 #endif /* CHECKING_P */
 330   ret.p = (void *) arg;
 331   return ret;
 332 }
 333 #endif /* GCC_TM_H */
 334
 335 #endif /* GCC_TARGET_H */