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/* These are defined in tree-vect-stmts.cc. */
169extern tree stmt_vectype (class _stmt_vec_info *);
170extern bool stmt_in_inner_loop_p (class vec_info *, class _stmt_vec_info *);
171
172/* Assembler instructions for creating various kinds of integer object. */
173
175{
176 const char *hi;
177 const char *psi;
178 const char *si;
179 const char *pdi;
180 const char *di;
181 const char *pti;
182 const char *ti;
183};
184
185/* Types of costs for vectorizer cost model. */
206
207/* Separate locations for which the vectorizer cost model should
208 track costs. */
214
215class vec_perm_indices;
216
217/* The type to use for lists of vector sizes. */
219
220/* Same, but can be used to construct local lists that are
221 automatically freed. */
223
224/* First argument of targetm.omp.device_kind_arch_isa. */
230
231/* Flags returned by TARGET_VECTORIZE_AUTOVECTORIZE_VECTOR_MODES:
232
233 VECT_COMPARE_COSTS
234 Tells the loop vectorizer to try all the provided modes and
235 pick the one with the lowest cost. By default the vectorizer
236 will choose the first mode that works. */
237const unsigned int VECT_COMPARE_COSTS = 1U << 0;
238
239/* The contexts in which the use of a type T can be checked by
240 TARGET_VERIFY_TYPE_CONTEXT. */
242 /* Directly measuring the size of T. */
244
245 /* Directly measuring the alignment of T. */
247
248 /* Creating objects of type T with static storage duration. */
250
251 /* Creating objects of type T with thread-local storage duration. */
253
254 /* Creating a field of type T. */
256
257 /* Creating an array with elements of type T. */
259
260 /* Adding to or subtracting from a pointer to T, or computing the
261 difference between two pointers when one of them is a pointer to T. */
263
264 /* Dynamically allocating objects of type T. */
266
267 /* Dynamically deallocating objects of type T. */
269
270 /* Throwing or catching an object of type T. */
272
273 /* Capturing objects of type T by value in a closure. */
276
283
285
287 bool = false);
288
289/* The target structure. This holds all the backend hooks. */
290#define DEFHOOKPOD(NAME, DOC, TYPE, INIT) TYPE NAME;
291#define DEFHOOK(NAME, DOC, TYPE, PARAMS, INIT) TYPE (* NAME) PARAMS;
292#define DEFHOOK_UNDOC DEFHOOK
293#define HOOKSTRUCT(FRAGMENT) FRAGMENT
294
295#include "target.def"
296
297extern struct gcc_target targetm;
298
299/* Return an estimate of the runtime value of X, for use in things
300 like cost calculations or profiling frequencies. Note that this
301 function should never be used in situations where the actual
302 runtime value is needed for correctness, since the function only
303 provides a rough guess. */
304
305inline HOST_WIDE_INT
308{
309 if (NUM_POLY_INT_COEFFS == 1)
310 return x.coeffs[0];
311 else
312 return targetm.estimated_poly_value (x, kind);
313}
314
315#ifdef GCC_TM_H
316
317#ifndef CUMULATIVE_ARGS_MAGIC
318#define CUMULATIVE_ARGS_MAGIC ((void *) &targetm.calls)
319#endif
320
321inline CUMULATIVE_ARGS *
323{
324#if CHECKING_P
325 gcc_assert (arg.magic == CUMULATIVE_ARGS_MAGIC);
326#endif /* CHECKING_P */
327 return (CUMULATIVE_ARGS *) arg.p;
328}
329
332{
334
335#if CHECKING_P
337#endif /* CHECKING_P */
338 ret.p = (void *) arg;
339 return ret;
340}
341#endif /* GCC_TM_H */
342
343#endif /* GCC_TARGET_H */
Definition tree-vectorizer.h:1258
Definition tree-ssa-alias.h:72
Definition vec.h:1656
Definition calls.h:35
Definition cfgloop.h:120
C coeffs[N]
Definition poly-int.h:429
Definition function-abi.h:35
Definition tree-vectorizer.h:448
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
T * ggc_alloc(ALONE_CXX_MEM_STAT_INFO)
Definition ggc.h:184
Definition target.h:175
const char * pdi
Definition target.h:179
const char * pti
Definition target.h:181
const char * psi
Definition target.h:177
const char * hi
Definition target.h:176
const char * di
Definition target.h:180
const char * si
Definition target.h:178
const char * ti
Definition target.h:182
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:50
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 vec.h:450
#define gcc_assert(EXPR)
Definition system.h:821
auto_vec< machine_mode, 8 > auto_vector_modes
Definition target.h:222
tree stmt_vectype(class _stmt_vec_info *)
Definition tree-vect-stmts.cc:67
bool verify_type_context(location_t, type_context_kind, const_tree, bool=false)
Definition tree.cc:14901
unsigned int get_move_ratio(bool)
Definition targhooks.cc:2063
vec< machine_mode > vector_modes
Definition target.h:218
unsigned HOST_WIDE_INT by_pieces_ninsns(unsigned HOST_WIDE_INT, unsigned int, unsigned int, by_pieces_operation)
Definition expr.cc:1091
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:75
bool target_default_pointer_address_modes_p(void)
Definition targhooks.cc:1678
poly_value_estimate_kind
Definition target.h:278
@ POLY_VALUE_LIKELY
Definition target.h:281
@ POLY_VALUE_MAX
Definition target.h:280
@ POLY_VALUE_MIN
Definition target.h:279
const unsigned int VECT_COMPARE_COSTS
Definition target.h:237
HOST_WIDE_INT estimated_poly_value(poly_int64 x, poly_value_estimate_kind kind=POLY_VALUE_LIKELY)
Definition target.h:306
type_context_kind
Definition target.h:241
@ TCTX_EXCEPTIONS
Definition target.h:271
@ TCTX_THREAD_STORAGE
Definition target.h:252
@ TCTX_STATIC_STORAGE
Definition target.h:249
@ TCTX_SIZEOF
Definition target.h:243
@ TCTX_POINTER_ARITH
Definition target.h:262
@ TCTX_ARRAY_ELEMENT
Definition target.h:258
@ TCTX_FIELD
Definition target.h:255
@ TCTX_ALLOCATION
Definition target.h:265
@ TCTX_CAPTURE_BY_COPY
Definition target.h:274
@ TCTX_ALIGNOF
Definition target.h:246
@ TCTX_DEALLOCATION
Definition target.h:268
void(* emit_support_tinfos_callback)(tree)
Definition target.h:284
void elf_record_gcc_switches(const char *)
Definition varasm.cc:8359
struct gcc_target targetm
vect_cost_model_location
Definition target.h:209
@ vect_body
Definition target.h:211
@ vect_prologue
Definition target.h:210
@ vect_epilogue
Definition target.h:212
vect_cost_for_stmt
Definition target.h:187
@ scalar_stmt
Definition target.h:188
@ vector_stmt
Definition target.h:191
@ vec_perm
Definition target.h:202
@ scalar_to_vec
Definition target.h:199
@ vec_construct
Definition target.h:204
@ vector_store
Definition target.h:196
@ unaligned_load
Definition target.h:194
@ cond_branch_taken
Definition target.h:201
@ scalar_load
Definition target.h:189
@ vec_to_scalar
Definition target.h:198
@ vector_gather_load
Definition target.h:193
@ scalar_store
Definition target.h:190
@ vec_promote_demote
Definition target.h:203
@ vector_load
Definition target.h:192
@ cond_branch_not_taken
Definition target.h:200
@ unaligned_store
Definition target.h:195
@ vector_scatter_store
Definition target.h:197
omp_device_kind_arch_isa
Definition target.h:225
@ omp_device_isa
Definition target.h:228
@ omp_device_arch
Definition target.h:227
@ omp_device_kind
Definition target.h:226
Definition target.h:67
void * p
Definition target.h:67