GCC Middle and Back End API Reference
target.h
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1/* Data structure definitions for a generic GCC target.
2 Copyright (C) 2001-2024 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
57struct 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
67union 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 abi_limb_mode CEIL (N, GET_MODE_PRECISION (abi_limb_mode))
73 limbs, 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 limb_mode is either the same as abi_limb_mode, or some narrower mode
79 in which _BitInt lowering should actually perform operations in and
80 what libgcc _BitInt helpers should use.
81 E.g. abi_limb_mode could be TImode which is something some processor
82 specific ABI would specify to use, but it would be desirable to handle
83 it as an array of DImode instead for efficiency.
84 Note, abi_limb_mode can be different from limb_mode only if big_endian
85 matches WORDS_BIG_ENDIAN. */
86
88 machine_mode abi_limb_mode, limb_mode;
91};
92
93/* Types of memory operation understood by the "by_pieces" infrastructure.
94 Used by the TARGET_USE_BY_PIECES_INFRASTRUCTURE_P target hook and
95 internally by the functions in expr.cc. */
96
105
106extern unsigned HOST_WIDE_INT by_pieces_ninsns (unsigned HOST_WIDE_INT,
107 unsigned int,
108 unsigned int,
110
111/* An example implementation for ELF targets. Defined in varasm.cc */
112extern void elf_record_gcc_switches (const char *);
113
114/* Some places still assume that all pointer or address modes are the
115 standard Pmode and ptr_mode. These optimizations become invalid if
116 the target actually supports multiple different modes. For now,
117 we disable such optimizations on such targets, using this function. */
119
120/* For hooks which use the MOVE_RATIO macro, this gives the legacy default
121 behavior. */
122extern unsigned int get_move_ratio (bool);
123
124struct stdarg_info;
125struct spec_info_def;
127struct cgraph_node;
128struct cgraph_simd_clone;
129
130/* The struct used by the secondary_reload target hook. */
132{
133 /* icode is actually an enum insn_code, but we don't want to force every
134 file that includes target.h to include optabs.h . */
135 int icode;
136 int extra_cost; /* Cost for using (a) scratch register(s) to be taken
137 into account by copy_cost. */
138 /* The next two members are for the use of the backward
139 compatibility hook. */
141 int t_icode; /* Actually an enum insn_code - see above. */
142};
143
144/* This is defined in sched-int.h . */
145struct _dep;
146
147/* This is defined in ddg.h . */
148struct ddg;
149
150/* This is defined in cfgloop.h . */
151class loop;
152
153/* This is defined in ifcvt.h. */
154struct noce_if_info;
155
156/* This is defined in tree-ssa-alias.h. */
157class ao_ref;
158
159/* This is defined in tree-vectorizer.h. */
160class _stmt_vec_info;
161
162/* This is defined in calls.h. */
164
165/* This is defined in function-abi.h. */
167
168/* This is defined in avoid-store-forwarding.h. */
169struct store_fwd_info;
170
171/* These are defined in tree-vect-stmts.cc. */
172extern tree stmt_vectype (class _stmt_vec_info *);
173extern bool stmt_in_inner_loop_p (class vec_info *, class _stmt_vec_info *);
174
175/* Assembler instructions for creating various kinds of integer object. */
176
178{
179 const char *hi;
180 const char *psi;
181 const char *si;
182 const char *pdi;
183 const char *di;
184 const char *pti;
185 const char *ti;
186};
187
188/* Types of costs for vectorizer cost model. */
209
210/* Separate locations for which the vectorizer cost model should
211 track costs. */
217
218class vec_perm_indices;
219
220/* The type to use for lists of vector sizes. */
222
223/* Same, but can be used to construct local lists that are
224 automatically freed. */
226
227/* First argument of targetm.omp.device_kind_arch_isa. */
233
234/* Flags returned by TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES:
235
236 VECT_COMPARE_COSTS
237 Tells the loop vectorizer to try all the provided modes and
238 pick the one with the lowest cost. By default the vectorizer
239 will choose the first mode that works. */
240const unsigned int VECT_COMPARE_COSTS = 1U << 0;
241
242/* The contexts in which the use of a type T can be checked by
243 TARGET_VERIFY_TYPE_CONTEXT. */
245 /* Directly measuring the size of T. */
247
248 /* Directly measuring the alignment of T. */
250
251 /* Creating objects of type T with static storage duration. */
253
254 /* Creating objects of type T with thread-local storage duration. */
256
257 /* Creating a field of type T. */
259
260 /* Creating an array with elements of type T. */
262
263 /* Adding to or subtracting from a pointer to T, or computing the
264 difference between two pointers when one of them is a pointer to T. */
266
267 /* Dynamically allocating objects of type T. */
269
270 /* Dynamically deallocating objects of type T. */
272
273 /* Throwing or catching an object of type T. */
275
276 /* Capturing objects of type T by value in a closure. */
279
286
288
289extern bool verify_type_context (location_t, type_context_kind, const_tree,
290 bool = false);
291
292/* The target structure. This holds all the backend hooks. */
293#define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
294#define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
295#define DEFHOOK_UNDOC DEFHOOK
296#define HOOKSTRUCT(FRAGMENT) FRAGMENT
297
298#include "target.def"
299
300extern struct gcc_target targetm;
301
302/* Return an estimate of the runtime value of X, for use in things
303 like cost calculations or profiling frequencies. Note that this
304 function should never be used in situations where the actual
305 runtime value is needed for correctness, since the function only
306 provides a rough guess. */
307
308inline HOST_WIDE_INT
311{
312 if (NUM_POLY_INT_COEFFS == 1)
313 return x.coeffs[0];
314 else
315 return targetm.estimated_poly_value (x, kind);
316}
317
318/* Return true when MODE can be used to copy GET_MODE_BITSIZE bits
319 unchanged. */
320
321inline bool
322mode_can_transfer_bits (machine_mode mode)
323{
324 if (mode == BLKmode)
325 return true;
326 if (maybe_ne (GET_MODE_BITSIZE (mode),
328 return false;
329 if (targetm.mode_can_transfer_bits)
330 return targetm.mode_can_transfer_bits (mode);
331 return true;
332}
333
334#ifdef GCC_TM_H
335
336#ifndef CUMULATIVE_ARGS_MAGIC
337#define CUMULATIVE_ARGS_MAGIC ((void *) &targetm.calls)
338#endif
339
340inline CUMULATIVE_ARGS *
341get_cumulative_args (cumulative_args_t arg)
342{
343#if CHECKING_P
344 gcc_assert (arg.magic == CUMULATIVE_ARGS_MAGIC);
345#endif /* CHECKING_P */
346 return (CUMULATIVE_ARGS *) arg.p;
347}
348
350pack_cumulative_args (CUMULATIVE_ARGS *arg)
351{
353
354#if CHECKING_P
355 ret.magic = CUMULATIVE_ARGS_MAGIC;
356#endif /* CHECKING_P */
357 ret.p = (void *) arg;
358 return ret;
359}
360#endif /* GCC_TM_H */
361
362#endif /* GCC_TARGET_H */
Definition tree-vectorizer.h:1290
Definition tree-ssa-alias.h:77
Definition vec.h:1656
Definition calls.h:35
Definition cfgloop.h:120
C coeffs[N]
Definition poly-int.h:433
Definition function-abi.h:35
Definition tree-vectorizer.h:490
Definition vec-perm-indices.h:51
const union tree_node * const_tree
Definition coretypes.h:98
union tree_node * tree
Definition coretypes.h:97
#define NUM_POLY_INT_COEFFS
Definition genmodes.cc:859
#define GET_MODE_UNIT_PRECISION(MODE)
Definition machmode.h:760
ALWAYS_INLINE poly_uint16 GET_MODE_BITSIZE(machine_mode mode)
Definition machmode.h:683
ALWAYS_INLINE poly_uint16 GET_MODE_NUNITS(machine_mode mode)
Definition machmode.h:769
Definition target.h:178
const char * pdi
Definition target.h:182
const char * pti
Definition target.h:184
const char * psi
Definition target.h:180
const char * hi
Definition target.h:179
const char * di
Definition target.h:183
const char * si
Definition target.h:181
const char * ti
Definition target.h:185
Definition target.h:87
machine_mode limb_mode
Definition target.h:88
bool big_endian
Definition target.h:89
bool extended
Definition target.h:90
machine_mode abi_limb_mode
Definition target.h:88
Definition cgraph.h:875
Definition cgraph.h:784
Definition ddg.h:108
Definition hard-reg-set.h:136
Definition ifcvt.h:66
Definition target.h:132
int icode
Definition target.h:135
int extra_cost
Definition target.h:136
struct secondary_reload_info * prev_sri
Definition target.h:140
int t_icode
Definition target.h:141
Definition tree-stdarg.h:25
Definition avoid-store-forwarding.h:31
Definition vec.h:450
#define gcc_assert(EXPR)
Definition system.h:814
auto_vec< machine_mode, 8 > auto_vector_modes
Definition target.h:225
tree stmt_vectype(class _stmt_vec_info *)
Definition tree-vect-stmts.cc:68
bool verify_type_context(location_t, type_context_kind, const_tree, bool=false)
Definition tree.cc:15049
unsigned int get_move_ratio(bool)
Definition targhooks.cc:2098
vec< machine_mode > vector_modes
Definition target.h:221
unsigned HOST_WIDE_INT by_pieces_ninsns(unsigned HOST_WIDE_INT, unsigned int, unsigned int, by_pieces_operation)
Definition expr.cc:1121
by_pieces_operation
Definition target.h:98
@ SET_BY_PIECES
Definition target.h:101
@ MOVE_BY_PIECES
Definition target.h:100
@ COMPARE_BY_PIECES
Definition target.h:103
@ CLEAR_BY_PIECES
Definition target.h:99
@ STORE_BY_PIECES
Definition target.h:102
bool stmt_in_inner_loop_p(class vec_info *, class _stmt_vec_info *)
Definition tree-vect-stmts.cc:76
bool target_default_pointer_address_modes_p(void)
Definition targhooks.cc:1707
poly_value_estimate_kind
Definition target.h:281
@ POLY_VALUE_LIKELY
Definition target.h:284
@ POLY_VALUE_MAX
Definition target.h:283
@ POLY_VALUE_MIN
Definition target.h:282
const unsigned int VECT_COMPARE_COSTS
Definition target.h:240
HOST_WIDE_INT estimated_poly_value(poly_int64 x, poly_value_estimate_kind kind=POLY_VALUE_LIKELY)
Definition target.h:309
type_context_kind
Definition target.h:244
@ TCTX_EXCEPTIONS
Definition target.h:274
@ TCTX_THREAD_STORAGE
Definition target.h:255
@ TCTX_STATIC_STORAGE
Definition target.h:252
@ TCTX_SIZEOF
Definition target.h:246
@ TCTX_POINTER_ARITH
Definition target.h:265
@ TCTX_ARRAY_ELEMENT
Definition target.h:261
@ TCTX_FIELD
Definition target.h:258
@ TCTX_ALLOCATION
Definition target.h:268
@ TCTX_CAPTURE_BY_COPY
Definition target.h:277
@ TCTX_ALIGNOF
Definition target.h:249
@ TCTX_DEALLOCATION
Definition target.h:271
void(* emit_support_tinfos_callback)(tree)
Definition target.h:287
void elf_record_gcc_switches(const char *)
Definition varasm.cc:8559
struct gcc_target targetm
vect_cost_model_location
Definition target.h:212
@ vect_body
Definition target.h:214
@ vect_prologue
Definition target.h:213
@ vect_epilogue
Definition target.h:215
vect_cost_for_stmt
Definition target.h:190
@ scalar_stmt
Definition target.h:191
@ vector_stmt
Definition target.h:194
@ vec_perm
Definition target.h:205
@ scalar_to_vec
Definition target.h:202
@ vec_construct
Definition target.h:207
@ vector_store
Definition target.h:199
@ unaligned_load
Definition target.h:197
@ cond_branch_taken
Definition target.h:204
@ scalar_load
Definition target.h:192
@ vec_to_scalar
Definition target.h:201
@ vector_gather_load
Definition target.h:196
@ scalar_store
Definition target.h:193
@ vec_promote_demote
Definition target.h:206
@ vector_load
Definition target.h:195
@ cond_branch_not_taken
Definition target.h:203
@ unaligned_store
Definition target.h:198
@ vector_scatter_store
Definition target.h:200
bool mode_can_transfer_bits(machine_mode mode)
Definition target.h:322
omp_device_kind_arch_isa
Definition target.h:228
@ omp_device_isa
Definition target.h:231
@ omp_device_arch
Definition target.h:230
@ omp_device_kind
Definition target.h:229
Definition target.h:67
void * p
Definition target.h:67