gcc/target.h

   1 /* Data structure definitions for a generic GCC target.
   2    Copyright (C) 2001-2020 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 class 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 class ao_ref;
 148
 149 /* This is defined in tree-vectorizer.h.  */
 150 class _stmt_vec_info;
 151
 152 /* This is defined in calls.h.  */
 153 class function_arg_info;
 154
 155 /* This is defined in function-abi.h.  */
 156 class predefined_function_abi;
 157
 158 /* These are defined in tree-vect-stmts.c.  */
 159 extern tree stmt_vectype (class _stmt_vec_info *);
 160 extern bool stmt_in_inner_loop_p (class vec_info *, class _stmt_vec_info *);
 161
 162 /* Assembler instructions for creating various kinds of integer object.  */
 163
 164 struct asm_int_op
 165 {
 166   const char *hi;
 167   const char *psi;
 168   const char *si;
 169   const char *pdi;
 170   const char *di;
 171   const char *pti;
 172   const char *ti;
 173 };
 174
 175 /* Types of costs for vectorizer cost model.  */
 176 enum vect_cost_for_stmt
 177 {
 178   scalar_stmt,
 179   scalar_load,
 180   scalar_store,
 181   vector_stmt,
 182   vector_load,
 183   vector_gather_load,
 184   unaligned_load,
 185   unaligned_store,
 186   vector_store,
 187   vector_scatter_store,
 188   vec_to_scalar,
 189   scalar_to_vec,
 190   cond_branch_not_taken,
 191   cond_branch_taken,
 192   vec_perm,
 193   vec_promote_demote,
 194   vec_construct
 195 };
 196
 197 /* Separate locations for which the vectorizer cost model should
 198    track costs.  */
 199 enum vect_cost_model_location {
 200   vect_prologue = 0,
 201   vect_body = 1,
 202   vect_epilogue = 2
 203 };
 204
 205 class vec_perm_indices;
 206
 207 /* The type to use for lists of vector sizes.  */
 208 typedef vec<machine_mode> vector_modes;
 209
 210 /* Same, but can be used to construct local lists that are
 211    automatically freed.  */
 212 typedef auto_vec<machine_mode, 8> auto_vector_modes;
 213
 214 /* First argument of targetm.omp.device_kind_arch_isa.  */
 215 enum omp_device_kind_arch_isa {
 216   omp_device_kind,
 217   omp_device_arch,
 218   omp_device_isa
 219 };
 220
 221 /* Flags returned by TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES:
 222
 223    VECT_COMPARE_COSTS
 224        Tells the loop vectorizer to try all the provided modes and
 225        pick the one with the lowest cost.  By default the vectorizer
 226        will choose the first mode that works.  */
 227 const unsigned int VECT_COMPARE_COSTS = 1U << 0;
 228
 229 /* The contexts in which the use of a type T can be checked by
 230    TARGET_VERIFY_TYPE_CONTEXT.  */
 231 enum type_context_kind {
 232   /* Directly measuring the size of T.  */
 233   TCTX_SIZEOF,
 234
 235   /* Directly measuring the alignment of T.  */
 236   TCTX_ALIGNOF,
 237
 238   /* Creating objects of type T with static storage duration.  */
 239   TCTX_STATIC_STORAGE,
 240
 241   /* Creating objects of type T with thread-local storage duration.  */
 242   TCTX_THREAD_STORAGE,
 243
 244   /* Creating a field of type T.  */
 245   TCTX_FIELD,
 246
 247   /* Creating an array with elements of type T.  */
 248   TCTX_ARRAY_ELEMENT,
 249
 250   /* Adding to or subtracting from a pointer to T, or computing the
 251      difference between two pointers when one of them is a pointer to T.  */
 252   TCTX_POINTER_ARITH,
 253
 254   /* Dynamically allocating objects of type T.  */
 255   TCTX_ALLOCATION,
 256
 257   /* Dynamically deallocating objects of type T.  */
 258   TCTX_DEALLOCATION,
 259
 260   /* Throwing or catching an object of type T.  */
 261   TCTX_EXCEPTIONS,
 262
 263   /* Capturing objects of type T by value in a closure.  */
 264   TCTX_CAPTURE_BY_COPY
 265 };
 266
 267 extern bool verify_type_context (location_t, type_context_kind, const_tree,
 268                                  bool = false);
 269
 270 /* The target structure.  This holds all the backend hooks.  */
 271 #define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
 272 #define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
 273 #define DEFHOOK_UNDOC DEFHOOK
 274 #define HOOKSTRUCT(FRAGMENT) FRAGMENT
 275
 276 #include "target.def"
 277
 278 extern struct gcc_target targetm;
 279
 280 /* Return an estimate of the runtime value of X, for use in things
 281    like cost calculations or profiling frequencies.  Note that this
 282    function should never be used in situations where the actual
 283    runtime value is needed for correctness, since the function only
 284    provides a rough guess.  */
 285
 286 static inline HOST_WIDE_INT
 287 estimated_poly_value (poly_int64 x)
 288 {
 289   if (NUM_POLY_INT_COEFFS == 1)
 290     return x.coeffs[0];
 291   else
 292     return targetm.estimated_poly_value (x);
 293 }
 294
 295 #ifdef GCC_TM_H
 296
 297 #ifndef CUMULATIVE_ARGS_MAGIC
 298 #define CUMULATIVE_ARGS_MAGIC ((void *) &targetm.calls)
 299 #endif
 300
 301 static inline CUMULATIVE_ARGS *
 302 get_cumulative_args (cumulative_args_t arg)
 303 {
 304 #if CHECKING_P
 305   gcc_assert (arg.magic == CUMULATIVE_ARGS_MAGIC);
 306 #endif /* CHECKING_P */
 307   return (CUMULATIVE_ARGS *) arg.p;
 308 }
 309
 310 static inline cumulative_args_t
 311 pack_cumulative_args (CUMULATIVE_ARGS *arg)
 312 {
 313   cumulative_args_t ret;
 314
 315 #if CHECKING_P
 316   ret.magic = CUMULATIVE_ARGS_MAGIC;
 317 #endif /* CHECKING_P */
 318   ret.p = (void *) arg;
 319   return ret;
 320 }
 321 #endif /* GCC_TM_H */
 322
 323 #endif /* GCC_TARGET_H */