1 /* Definitions for code generation pass of GNU compiler.
2 Copyright (C) 1987-2022 Free Software Foundation, Inc.
3
4 This file is part of GCC.
5
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
19
20 #ifndef GCC_EXPR_H
21 #define GCC_EXPR_H
22
23 /* This is the 4th arg to `expand_expr'.
24 EXPAND_STACK_PARM means we are possibly expanding a call param onto
25 the stack.
26 EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
27 EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
28 EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
29 is a constant that is not a legitimate address.
30 EXPAND_WRITE means we are only going to write to the resulting rtx.
31 EXPAND_MEMORY means we are interested in a memory result, even if
32 the memory is constant and we could have propagated a constant value,
33 or the memory is unaligned on a STRICT_ALIGNMENT target. */
34 enum expand_modifier {EXPAND_NORMAL = 0, EXPAND_STACK_PARM, EXPAND_SUM,
35 EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE,
36 EXPAND_MEMORY};
37
38 /* Prevent the compiler from deferring stack pops. See
39 inhibit_defer_pop for more information. */
40 #define NO_DEFER_POP (inhibit_defer_pop += 1)
41
42 /* Allow the compiler to defer stack pops. See inhibit_defer_pop for
43 more information. */
44 #define OK_DEFER_POP (inhibit_defer_pop -= 1)
45
46 /* This structure is used to pass around information about exploded
47 unary, binary and trinary expressions between expand_expr_real_1 and
48 friends. */
49 typedef struct separate_ops
50 {
51 enum tree_code code;
52 location_t location;
53 tree type;
54 tree op0, op1, op2;
55 } *sepops;
56
57 /* This is run during target initialization to set up which modes can be
58 used directly in memory and to initialize the block move optab. */
59 extern void init_expr_target (void);
60
61 /* This is run at the start of compiling a function. */
62 extern void init_expr (void);
63
64 /* Emit some rtl insns to move data between rtx's, converting machine modes.
65 Both modes must be floating or both fixed. */
66 extern void convert_move (rtx, rtx, int);
67
68 /* Convert an rtx to specified machine mode and return the result. */
69 extern rtx convert_to_mode (machine_mode, rtx, int);
70
71 /* Convert an rtx to MODE from OLDMODE and return the result. */
72 extern rtx convert_modes (machine_mode, machine_mode, rtx, int);
73
74 /* Expand a call to memcpy or memmove or memcmp, and return the result. */
75 extern rtx emit_block_op_via_libcall (enum built_in_function, rtx, rtx, rtx,
76 bool);
77
78 static inline rtx
79 emit_block_copy_via_libcall (rtx dst, rtx src, rtx size, bool tailcall = false)
80 {
81 return emit_block_op_via_libcall (BUILT_IN_MEMCPY, dst, src, size, tailcall);
82 }
83
84 static inline rtx
85 emit_block_move_via_libcall (rtx dst, rtx src, rtx size, bool tailcall = false)
86 {
87 return emit_block_op_via_libcall (BUILT_IN_MEMMOVE, dst, src, size, tailcall);
88 }
89
90 static inline rtx
91 emit_block_comp_via_libcall (rtx dst, rtx src, rtx size, bool tailcall = false)
92 {
93 return emit_block_op_via_libcall (BUILT_IN_MEMCMP, dst, src, size, tailcall);
94 }
95
96 /* Emit code to move a block Y to a block X. */
97 enum block_op_methods
98 {
99 BLOCK_OP_NORMAL,
100 BLOCK_OP_NO_LIBCALL,
101 BLOCK_OP_CALL_PARM,
102 /* Like BLOCK_OP_NORMAL, but the libcall can be tail call optimized. */
103 BLOCK_OP_TAILCALL,
104 /* Like BLOCK_OP_NO_LIBCALL, but instead of emitting a libcall return
105 pc_rtx to indicate nothing has been emitted and let the caller handle
106 it. */
107 BLOCK_OP_NO_LIBCALL_RET
108 };
109
110 typedef rtx (*by_pieces_constfn) (void *, void *, HOST_WIDE_INT,
111 fixed_size_mode);
112
113 /* The second pointer passed to by_pieces_constfn. */
114 struct by_pieces_prev
115 {
116 rtx data;
117 fixed_size_mode mode;
118 };
119
120 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
121 extern rtx emit_block_move_hints (rtx, rtx, rtx, enum block_op_methods,
122 unsigned int, HOST_WIDE_INT,
123 unsigned HOST_WIDE_INT,
124 unsigned HOST_WIDE_INT,
125 unsigned HOST_WIDE_INT,
126 bool bail_out_libcall = false,
127 bool *is_move_done = NULL,
128 bool might_overlap = false);
129 extern rtx emit_block_cmp_hints (rtx, rtx, rtx, tree, rtx, bool,
130 by_pieces_constfn, void *);
131 extern bool emit_storent_insn (rtx to, rtx from);
132
133 /* Copy all or part of a value X into registers starting at REGNO.
134 The number of registers to be filled is NREGS. */
135 extern void move_block_to_reg (int, rtx, int, machine_mode);
136
137 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
138 The number of registers to be filled is NREGS. */
139 extern void move_block_from_reg (int, rtx, int);
140
141 /* Generate a non-consecutive group of registers represented by a PARALLEL. */
142 extern rtx gen_group_rtx (rtx);
143
144 /* Load a BLKmode value into non-consecutive registers represented by a
145 PARALLEL. */
146 extern void emit_group_load (rtx, rtx, tree, poly_int64);
147
148 /* Similarly, but load into new temporaries. */
149 extern rtx emit_group_load_into_temps (rtx, rtx, tree, poly_int64);
150
151 /* Move a non-consecutive group of registers represented by a PARALLEL into
152 a non-consecutive group of registers represented by a PARALLEL. */
153 extern void emit_group_move (rtx, rtx);
154
155 /* Move a group of registers represented by a PARALLEL into pseudos. */
156 extern rtx emit_group_move_into_temps (rtx);
157
158 /* Store a BLKmode value from non-consecutive registers represented by a
159 PARALLEL. */
160 extern void emit_group_store (rtx, rtx, tree, poly_int64);
161
162 extern rtx maybe_emit_group_store (rtx, tree);
163
164 /* Mark REG as holding a parameter for the next CALL_INSN.
165 Mode is TYPE_MODE of the non-promoted parameter, or VOIDmode. */
166 extern void use_reg_mode (rtx *, rtx, machine_mode);
167 extern void clobber_reg_mode (rtx *, rtx, machine_mode);
168
169 extern rtx copy_blkmode_to_reg (machine_mode, tree);
170
171 /* Mark REG as holding a parameter for the next CALL_INSN. */
172 static inline void
use_reg(rtx * fusage,rtx reg)173 use_reg (rtx *fusage, rtx reg)
174 {
175 use_reg_mode (fusage, reg, VOIDmode);
176 }
177
178 /* Mark REG as clobbered by the call with FUSAGE as CALL_INSN_FUNCTION_USAGE. */
179 static inline void
clobber_reg(rtx * fusage,rtx reg)180 clobber_reg (rtx *fusage, rtx reg)
181 {
182 clobber_reg_mode (fusage, reg, VOIDmode);
183 }
184
185 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
186 for the next CALL_INSN. */
187 extern void use_regs (rtx *, int, int);
188
189 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN. */
190 extern void use_group_regs (rtx *, rtx);
191
192 #ifdef GCC_INSN_CODES_H
193 extern rtx expand_cmpstrn_or_cmpmem (insn_code, rtx, rtx, rtx, tree, rtx,
194 HOST_WIDE_INT);
195 #endif
196
197 /* Write zeros through the storage of OBJECT.
198 If OBJECT has BLKmode, SIZE is its length in bytes. */
199 extern rtx clear_storage (rtx, rtx, enum block_op_methods);
200 extern rtx clear_storage_hints (rtx, rtx, enum block_op_methods,
201 unsigned int, HOST_WIDE_INT,
202 unsigned HOST_WIDE_INT,
203 unsigned HOST_WIDE_INT,
204 unsigned HOST_WIDE_INT,
205 unsigned);
206 /* The same, but always output an library call. */
207 extern rtx set_storage_via_libcall (rtx, rtx, rtx, bool = false);
208
209 /* Expand a setmem pattern; return true if successful. */
210 extern bool set_storage_via_setmem (rtx, rtx, rtx, unsigned int,
211 unsigned int, HOST_WIDE_INT,
212 unsigned HOST_WIDE_INT,
213 unsigned HOST_WIDE_INT,
214 unsigned HOST_WIDE_INT);
215
216 /* Return nonzero if it is desirable to store LEN bytes generated by
217 CONSTFUN with several move instructions by store_by_pieces
218 function. CONSTFUNDATA is a pointer which will be passed as argument
219 in every CONSTFUN call.
220 ALIGN is maximum alignment we can assume.
221 MEMSETP is true if this is a real memset/bzero, not a copy
222 of a const string. */
223 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
224 by_pieces_constfn,
225 void *, unsigned int, bool);
226
227 /* Generate several move instructions to store LEN bytes generated by
228 CONSTFUN to block TO. (A MEM rtx with BLKmode). CONSTFUNDATA is a
229 pointer which will be passed as argument in every CONSTFUN call.
230 ALIGN is maximum alignment we can assume.
231 MEMSETP is true if this is a real memset/bzero, not a copy.
232 Returns TO + LEN. */
233 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT, by_pieces_constfn,
234 void *, unsigned int, bool, memop_ret);
235
236 /* If can_store_by_pieces passes for worst-case values near MAX_LEN, call
237 store_by_pieces within conditionals so as to handle variable LEN efficiently,
238 storing VAL, if non-NULL_RTX, or valc instead. */
239 extern bool try_store_by_multiple_pieces (rtx to, rtx len,
240 unsigned int ctz_len,
241 unsigned HOST_WIDE_INT min_len,
242 unsigned HOST_WIDE_INT max_len,
243 rtx val, char valc,
244 unsigned int align);
245
246 /* Emit insns to set X from Y. */
247 extern rtx_insn *emit_move_insn (rtx, rtx);
248 extern rtx_insn *gen_move_insn (rtx, rtx);
249
250 /* Emit insns to set X from Y, with no frills. */
251 extern rtx_insn *emit_move_insn_1 (rtx, rtx);
252
253 extern rtx_insn *emit_move_complex_push (machine_mode, rtx, rtx);
254 extern rtx_insn *emit_move_complex_parts (rtx, rtx);
255 extern rtx read_complex_part (rtx, bool);
256 extern void write_complex_part (rtx, rtx, bool);
257 extern rtx read_complex_part (rtx, bool);
258 extern rtx emit_move_resolve_push (machine_mode, rtx);
259
260 /* Push a block of length SIZE (perhaps variable)
261 and return an rtx to address the beginning of the block. */
262 extern rtx push_block (rtx, poly_int64, int);
263
264 /* Generate code to push something onto the stack, given its mode and type. */
265 extern bool emit_push_insn (rtx, machine_mode, tree, rtx, unsigned int,
266 int, rtx, poly_int64, rtx, rtx, int, rtx, bool);
267
268 /* Extract the accessible bit-range from a COMPONENT_REF. */
269 extern void get_bit_range (poly_uint64_pod *, poly_uint64_pod *, tree,
270 poly_int64_pod *, tree *);
271
272 /* Expand an assignment that stores the value of FROM into TO. */
273 extern void expand_assignment (tree, tree, bool);
274
275 /* Generate code for computing expression EXP,
276 and storing the value into TARGET.
277 If SUGGEST_REG is nonzero, copy the value through a register
278 and return that register, if that is possible. */
279 extern rtx store_expr (tree, rtx, int, bool, bool);
280
281 /* Given an rtx that may include add and multiply operations,
282 generate them as insns and return a pseudo-reg containing the value.
283 Useful after calling expand_expr with 1 as sum_ok. */
284 extern rtx force_operand (rtx, rtx);
285
286 /* Work horses for expand_expr. */
287 extern rtx expand_expr_real (tree, rtx, machine_mode,
288 enum expand_modifier, rtx *, bool);
289 extern rtx expand_expr_real_1 (tree, rtx, machine_mode,
290 enum expand_modifier, rtx *, bool);
291 extern rtx expand_expr_real_2 (sepops, rtx, machine_mode,
292 enum expand_modifier);
293
294 /* Generate code for computing expression EXP.
295 An rtx for the computed value is returned. The value is never null.
296 In the case of a void EXP, const0_rtx is returned. */
297 static inline rtx
expand_expr(tree exp,rtx target,machine_mode mode,enum expand_modifier modifier)298 expand_expr (tree exp, rtx target, machine_mode mode,
299 enum expand_modifier modifier)
300 {
301 return expand_expr_real (exp, target, mode, modifier, NULL, false);
302 }
303
304 static inline rtx
expand_normal(tree exp)305 expand_normal (tree exp)
306 {
307 return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL, false);
308 }
309
310
311 /* Return STRING_CST and set offset, size and decl, if the first
312 argument corresponds to a string constant. */
313 extern tree string_constant (tree, tree *, tree *, tree *);
314 /* Similar to string_constant, return a STRING_CST corresponding
315 to the value representation of the first argument if it's
316 a constant. */
317 extern tree byte_representation (tree, tree *, tree *, tree *);
318
319 extern enum tree_code maybe_optimize_mod_cmp (enum tree_code, tree *, tree *);
320 extern void maybe_optimize_sub_cmp_0 (enum tree_code, tree *, tree *);
321
322 /* Two different ways of generating switch statements. */
323 extern int try_casesi (tree, tree, tree, tree, rtx, rtx, rtx, profile_probability);
324 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx, profile_probability);
325
326 extern int safe_from_p (const_rtx, tree, int);
327
328 /* Get the personality libfunc for a function decl. */
329 rtx get_personality_function (tree);
330
331 /* Determine whether the LEN bytes can be moved by using several move
332 instructions. Return nonzero if a call to move_by_pieces should
333 succeed. */
334 extern bool can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
335
336 extern unsigned HOST_WIDE_INT highest_pow2_factor (const_tree);
337
338 extern bool categorize_ctor_elements (const_tree, HOST_WIDE_INT *,
339 HOST_WIDE_INT *, HOST_WIDE_INT *,
340 bool *);
341
342 extern void expand_operands (tree, tree, rtx, rtx*, rtx*,
343 enum expand_modifier);
344
345 /* rtl.h and tree.h were included. */
346 /* Return an rtx for the size in bytes of the value of an expr. */
347 extern rtx expr_size (tree);
348
349 extern bool mem_ref_refers_to_non_mem_p (tree);
350 extern bool non_mem_decl_p (tree);
351
352 #endif /* GCC_EXPR_H */
353