1 /* Definitions for code generation pass of GNU compiler.
2 Copyright (C) 1987-2020 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 *, HOST_WIDE_INT, scalar_int_mode);
111
112 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
113 extern rtx emit_block_move_hints (rtx, rtx, rtx, enum block_op_methods,
114 unsigned int, HOST_WIDE_INT,
115 unsigned HOST_WIDE_INT,
116 unsigned HOST_WIDE_INT,
117 unsigned HOST_WIDE_INT,
118 bool bail_out_libcall = false,
119 bool *is_move_done = NULL,
120 bool might_overlap = false);
121 extern rtx emit_block_cmp_hints (rtx, rtx, rtx, tree, rtx, bool,
122 by_pieces_constfn, void *);
123 extern bool emit_storent_insn (rtx to, rtx from);
124
125 /* Copy all or part of a value X into registers starting at REGNO.
126 The number of registers to be filled is NREGS. */
127 extern void move_block_to_reg (int, rtx, int, machine_mode);
128
129 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
130 The number of registers to be filled is NREGS. */
131 extern void move_block_from_reg (int, rtx, int);
132
133 /* Generate a non-consecutive group of registers represented by a PARALLEL. */
134 extern rtx gen_group_rtx (rtx);
135
136 /* Load a BLKmode value into non-consecutive registers represented by a
137 PARALLEL. */
138 extern void emit_group_load (rtx, rtx, tree, poly_int64);
139
140 /* Similarly, but load into new temporaries. */
141 extern rtx emit_group_load_into_temps (rtx, rtx, tree, poly_int64);
142
143 /* Move a non-consecutive group of registers represented by a PARALLEL into
144 a non-consecutive group of registers represented by a PARALLEL. */
145 extern void emit_group_move (rtx, rtx);
146
147 /* Move a group of registers represented by a PARALLEL into pseudos. */
148 extern rtx emit_group_move_into_temps (rtx);
149
150 /* Store a BLKmode value from non-consecutive registers represented by a
151 PARALLEL. */
152 extern void emit_group_store (rtx, rtx, tree, poly_int64);
153
154 extern rtx maybe_emit_group_store (rtx, tree);
155
156 /* Mark REG as holding a parameter for the next CALL_INSN.
157 Mode is TYPE_MODE of the non-promoted parameter, or VOIDmode. */
158 extern void use_reg_mode (rtx *, rtx, machine_mode);
159 extern void clobber_reg_mode (rtx *, rtx, machine_mode);
160
161 extern rtx copy_blkmode_to_reg (machine_mode, tree);
162
163 /* Mark REG as holding a parameter for the next CALL_INSN. */
164 static inline void
use_reg(rtx * fusage,rtx reg)165 use_reg (rtx *fusage, rtx reg)
166 {
167 use_reg_mode (fusage, reg, VOIDmode);
168 }
169
170 /* Mark REG as clobbered by the call with FUSAGE as CALL_INSN_FUNCTION_USAGE. */
171 static inline void
clobber_reg(rtx * fusage,rtx reg)172 clobber_reg (rtx *fusage, rtx reg)
173 {
174 clobber_reg_mode (fusage, reg, VOIDmode);
175 }
176
177 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
178 for the next CALL_INSN. */
179 extern void use_regs (rtx *, int, int);
180
181 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN. */
182 extern void use_group_regs (rtx *, rtx);
183
184 #ifdef GCC_INSN_CODES_H
185 extern rtx expand_cmpstrn_or_cmpmem (insn_code, rtx, rtx, rtx, tree, rtx,
186 HOST_WIDE_INT);
187 #endif
188
189 /* Write zeros through the storage of OBJECT.
190 If OBJECT has BLKmode, SIZE is its length in bytes. */
191 extern rtx clear_storage (rtx, rtx, enum block_op_methods);
192 extern rtx clear_storage_hints (rtx, rtx, enum block_op_methods,
193 unsigned int, HOST_WIDE_INT,
194 unsigned HOST_WIDE_INT,
195 unsigned HOST_WIDE_INT,
196 unsigned HOST_WIDE_INT);
197 /* The same, but always output an library call. */
198 extern rtx set_storage_via_libcall (rtx, rtx, rtx, bool = false);
199
200 /* Expand a setmem pattern; return true if successful. */
201 extern bool set_storage_via_setmem (rtx, rtx, rtx, unsigned int,
202 unsigned int, HOST_WIDE_INT,
203 unsigned HOST_WIDE_INT,
204 unsigned HOST_WIDE_INT,
205 unsigned HOST_WIDE_INT);
206
207 /* Return nonzero if it is desirable to store LEN bytes generated by
208 CONSTFUN with several move instructions by store_by_pieces
209 function. CONSTFUNDATA is a pointer which will be passed as argument
210 in every CONSTFUN call.
211 ALIGN is maximum alignment we can assume.
212 MEMSETP is true if this is a real memset/bzero, not a copy
213 of a const string. */
214 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
215 by_pieces_constfn,
216 void *, unsigned int, bool);
217
218 /* Generate several move instructions to store LEN bytes generated by
219 CONSTFUN to block TO. (A MEM rtx with BLKmode). CONSTFUNDATA is a
220 pointer which will be passed as argument in every CONSTFUN call.
221 ALIGN is maximum alignment we can assume.
222 MEMSETP is true if this is a real memset/bzero, not a copy.
223 Returns TO + LEN. */
224 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT, by_pieces_constfn,
225 void *, unsigned int, bool, memop_ret);
226
227 /* Emit insns to set X from Y. */
228 extern rtx_insn *emit_move_insn (rtx, rtx);
229 extern rtx_insn *gen_move_insn (rtx, rtx);
230
231 /* Emit insns to set X from Y, with no frills. */
232 extern rtx_insn *emit_move_insn_1 (rtx, rtx);
233
234 extern rtx_insn *emit_move_complex_push (machine_mode, rtx, rtx);
235 extern rtx_insn *emit_move_complex_parts (rtx, rtx);
236 extern rtx read_complex_part (rtx, bool);
237 extern void write_complex_part (rtx, rtx, bool);
238 extern rtx read_complex_part (rtx, bool);
239 extern rtx emit_move_resolve_push (machine_mode, rtx);
240
241 /* Push a block of length SIZE (perhaps variable)
242 and return an rtx to address the beginning of the block. */
243 extern rtx push_block (rtx, poly_int64, int);
244
245 /* Generate code to push something onto the stack, given its mode and type. */
246 extern bool emit_push_insn (rtx, machine_mode, tree, rtx, unsigned int,
247 int, rtx, poly_int64, rtx, rtx, int, rtx, bool);
248
249 /* Extract the accessible bit-range from a COMPONENT_REF. */
250 extern void get_bit_range (poly_uint64_pod *, poly_uint64_pod *, tree,
251 poly_int64_pod *, tree *);
252
253 /* Expand an assignment that stores the value of FROM into TO. */
254 extern void expand_assignment (tree, tree, bool);
255
256 /* Generate code for computing expression EXP,
257 and storing the value into TARGET.
258 If SUGGEST_REG is nonzero, copy the value through a register
259 and return that register, if that is possible. */
260 extern rtx store_expr (tree, rtx, int, bool, bool);
261
262 /* Given an rtx that may include add and multiply operations,
263 generate them as insns and return a pseudo-reg containing the value.
264 Useful after calling expand_expr with 1 as sum_ok. */
265 extern rtx force_operand (rtx, rtx);
266
267 /* Work horses for expand_expr. */
268 extern rtx expand_expr_real (tree, rtx, machine_mode,
269 enum expand_modifier, rtx *, bool);
270 extern rtx expand_expr_real_1 (tree, rtx, machine_mode,
271 enum expand_modifier, rtx *, bool);
272 extern rtx expand_expr_real_2 (sepops, rtx, machine_mode,
273 enum expand_modifier);
274
275 /* Generate code for computing expression EXP.
276 An rtx for the computed value is returned. The value is never null.
277 In the case of a void EXP, const0_rtx is returned. */
278 static inline rtx
expand_expr(tree exp,rtx target,machine_mode mode,enum expand_modifier modifier)279 expand_expr (tree exp, rtx target, machine_mode mode,
280 enum expand_modifier modifier)
281 {
282 return expand_expr_real (exp, target, mode, modifier, NULL, false);
283 }
284
285 static inline rtx
expand_normal(tree exp)286 expand_normal (tree exp)
287 {
288 return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL, false);
289 }
290
291
292 /* Return the tree node and offset if a given argument corresponds to
293 a string constant. */
294 extern tree string_constant (tree, tree *, tree *, tree *);
295
296 extern enum tree_code maybe_optimize_mod_cmp (enum tree_code, tree *, tree *);
297
298 /* Two different ways of generating switch statements. */
299 extern int try_casesi (tree, tree, tree, tree, rtx, rtx, rtx, profile_probability);
300 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx, profile_probability);
301
302 extern int safe_from_p (const_rtx, tree, int);
303
304 /* Get the personality libfunc for a function decl. */
305 rtx get_personality_function (tree);
306
307 /* Determine whether the LEN bytes can be moved by using several move
308 instructions. Return nonzero if a call to move_by_pieces should
309 succeed. */
310 extern bool can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
311
312 extern unsigned HOST_WIDE_INT highest_pow2_factor (const_tree);
313
314 extern bool categorize_ctor_elements (const_tree, HOST_WIDE_INT *,
315 HOST_WIDE_INT *, HOST_WIDE_INT *,
316 bool *);
317
318 extern void expand_operands (tree, tree, rtx, rtx*, rtx*,
319 enum expand_modifier);
320
321 /* rtl.h and tree.h were included. */
322 /* Return an rtx for the size in bytes of the value of an expr. */
323 extern rtx expr_size (tree);
324
325 #endif /* GCC_EXPR_H */
326