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18ca7dab | 1 | /* Subroutines for manipulating rtx's in semantically interesting ways. |
7adcbafe | 2 | Copyright (C) 1987-2022 Free Software Foundation, Inc. |
18ca7dab | 3 | |
1322177d | 4 | This file is part of GCC. |
18ca7dab | 5 | |
1322177d LB |
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 | |
9dcd6f09 | 8 | Software Foundation; either version 3, or (at your option) any later |
1322177d | 9 | version. |
18ca7dab | 10 | |
1322177d LB |
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. | |
18ca7dab RK |
15 | |
16 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
18ca7dab RK |
19 | |
20 | ||
21 | #include "config.h" | |
670ee920 | 22 | #include "system.h" |
4977bab6 | 23 | #include "coretypes.h" |
957060b5 AM |
24 | #include "target.h" |
25 | #include "function.h" | |
18ca7dab RK |
26 | #include "rtl.h" |
27 | #include "tree.h" | |
4d0cdd0c | 28 | #include "memmodel.h" |
6baf1cc8 | 29 | #include "tm_p.h" |
e34153b0 | 30 | #include "optabs.h" |
957060b5 | 31 | #include "expmed.h" |
357067f2 | 32 | #include "profile-count.h" |
957060b5 AM |
33 | #include "emit-rtl.h" |
34 | #include "recog.h" | |
35 | #include "diagnostic-core.h" | |
957060b5 | 36 | #include "stor-layout.h" |
97909f80 | 37 | #include "langhooks.h" |
b38f3813 | 38 | #include "except.h" |
36566b39 PK |
39 | #include "dojump.h" |
40 | #include "explow.h" | |
18ca7dab | 41 | #include "expr.h" |
3cf3da88 | 42 | #include "stringpool.h" |
677f3fa8 | 43 | #include "common/common-target.h" |
aacd3885 | 44 | #include "output.h" |
18ca7dab | 45 | |
502b8322 | 46 | static rtx break_out_memory_refs (rtx); |
7e4ce834 RH |
47 | |
48 | ||
49 | /* Truncate and perhaps sign-extend C as appropriate for MODE. */ | |
50 | ||
51 | HOST_WIDE_INT | |
ef4bddc2 | 52 | trunc_int_for_mode (HOST_WIDE_INT c, machine_mode mode) |
7e4ce834 | 53 | { |
db61b7f9 RS |
54 | /* Not scalar_int_mode because we also allow pointer bound modes. */ |
55 | scalar_mode smode = as_a <scalar_mode> (mode); | |
56 | int width = GET_MODE_PRECISION (smode); | |
7e4ce834 | 57 | |
71012d97 | 58 | /* You want to truncate to a _what_? */ |
eafa30ef | 59 | gcc_assert (SCALAR_INT_MODE_P (mode)); |
71012d97 | 60 | |
1f3f36d1 | 61 | /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */ |
db61b7f9 | 62 | if (smode == BImode) |
1f3f36d1 RH |
63 | return c & 1 ? STORE_FLAG_VALUE : 0; |
64 | ||
5b0d91c3 AO |
65 | /* Sign-extend for the requested mode. */ |
66 | ||
67 | if (width < HOST_BITS_PER_WIDE_INT) | |
68 | { | |
69 | HOST_WIDE_INT sign = 1; | |
70 | sign <<= width - 1; | |
71 | c &= (sign << 1) - 1; | |
72 | c ^= sign; | |
73 | c -= sign; | |
74 | } | |
7e4ce834 RH |
75 | |
76 | return c; | |
77 | } | |
78 | ||
0c12fc9b RS |
79 | /* Likewise for polynomial values, using the sign-extended representation |
80 | for each individual coefficient. */ | |
81 | ||
82 | poly_int64 | |
83 | trunc_int_for_mode (poly_int64 x, machine_mode mode) | |
84 | { | |
85 | for (unsigned int i = 0; i < NUM_POLY_INT_COEFFS; ++i) | |
86 | x.coeffs[i] = trunc_int_for_mode (x.coeffs[i], mode); | |
87 | return x; | |
88 | } | |
89 | ||
929e10f4 | 90 | /* Return an rtx for the sum of X and the integer C, given that X has |
23b33725 RS |
91 | mode MODE. INPLACE is true if X can be modified inplace or false |
92 | if it must be treated as immutable. */ | |
18ca7dab RK |
93 | |
94 | rtx | |
0c12fc9b | 95 | plus_constant (machine_mode mode, rtx x, poly_int64 c, bool inplace) |
18ca7dab | 96 | { |
b3694847 | 97 | RTX_CODE code; |
17ab7c59 | 98 | rtx y; |
b3694847 | 99 | rtx tem; |
18ca7dab RK |
100 | int all_constant = 0; |
101 | ||
0a81f074 RS |
102 | gcc_assert (GET_MODE (x) == VOIDmode || GET_MODE (x) == mode); |
103 | ||
0c12fc9b | 104 | if (known_eq (c, 0)) |
18ca7dab RK |
105 | return x; |
106 | ||
107 | restart: | |
108 | ||
109 | code = GET_CODE (x); | |
17ab7c59 RK |
110 | y = x; |
111 | ||
18ca7dab RK |
112 | switch (code) |
113 | { | |
807e902e | 114 | CASE_CONST_SCALAR_INT: |
f079167a | 115 | return immed_wide_int_const (wi::add (rtx_mode_t (x, mode), c), mode); |
18ca7dab RK |
116 | case MEM: |
117 | /* If this is a reference to the constant pool, try replacing it with | |
118 | a reference to a new constant. If the resulting address isn't | |
119 | valid, don't return it because we have no way to validize it. */ | |
120 | if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF | |
121 | && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0))) | |
122 | { | |
8a27cf73 UB |
123 | rtx cst = get_pool_constant (XEXP (x, 0)); |
124 | ||
125 | if (GET_CODE (cst) == CONST_VECTOR | |
126 | && GET_MODE_INNER (GET_MODE (cst)) == mode) | |
127 | { | |
128 | cst = gen_lowpart (mode, cst); | |
129 | gcc_assert (cst); | |
130 | } | |
0ab503d3 JJ |
131 | else if (GET_MODE (cst) == VOIDmode |
132 | && get_pool_mode (XEXP (x, 0)) != mode) | |
133 | break; | |
2b568899 RB |
134 | if (GET_MODE (cst) == VOIDmode || GET_MODE (cst) == mode) |
135 | { | |
136 | tem = plus_constant (mode, cst, c); | |
137 | tem = force_const_mem (GET_MODE (x), tem); | |
138 | /* Targets may disallow some constants in the constant pool, thus | |
139 | force_const_mem may return NULL_RTX. */ | |
140 | if (tem && memory_address_p (GET_MODE (tem), XEXP (tem, 0))) | |
141 | return tem; | |
142 | } | |
18ca7dab RK |
143 | } |
144 | break; | |
145 | ||
146 | case CONST: | |
147 | /* If adding to something entirely constant, set a flag | |
148 | so that we can add a CONST around the result. */ | |
23b33725 RS |
149 | if (inplace && shared_const_p (x)) |
150 | inplace = false; | |
18ca7dab RK |
151 | x = XEXP (x, 0); |
152 | all_constant = 1; | |
153 | goto restart; | |
154 | ||
155 | case SYMBOL_REF: | |
156 | case LABEL_REF: | |
157 | all_constant = 1; | |
158 | break; | |
159 | ||
160 | case PLUS: | |
929e10f4 MS |
161 | /* The interesting case is adding the integer to a sum. Look |
162 | for constant term in the sum and combine with C. For an | |
163 | integer constant term or a constant term that is not an | |
164 | explicit integer, we combine or group them together anyway. | |
03d937fc R |
165 | |
166 | We may not immediately return from the recursive call here, lest | |
167 | all_constant gets lost. */ | |
e5671f2b | 168 | |
929e10f4 | 169 | if (CONSTANT_P (XEXP (x, 1))) |
03d937fc | 170 | { |
23b33725 RS |
171 | rtx term = plus_constant (mode, XEXP (x, 1), c, inplace); |
172 | if (term == const0_rtx) | |
173 | x = XEXP (x, 0); | |
174 | else if (inplace) | |
175 | XEXP (x, 1) = term; | |
176 | else | |
177 | x = gen_rtx_PLUS (mode, XEXP (x, 0), term); | |
03d937fc R |
178 | c = 0; |
179 | } | |
23b33725 | 180 | else if (rtx *const_loc = find_constant_term_loc (&y)) |
03d937fc | 181 | { |
23b33725 RS |
182 | if (!inplace) |
183 | { | |
184 | /* We need to be careful since X may be shared and we can't | |
185 | modify it in place. */ | |
186 | x = copy_rtx (x); | |
187 | const_loc = find_constant_term_loc (&x); | |
188 | } | |
189 | *const_loc = plus_constant (mode, *const_loc, c, true); | |
03d937fc R |
190 | c = 0; |
191 | } | |
38a448ca | 192 | break; |
ed8908e7 | 193 | |
38a448ca | 194 | default: |
0c12fc9b RS |
195 | if (CONST_POLY_INT_P (x)) |
196 | return immed_wide_int_const (const_poly_int_value (x) + c, mode); | |
38a448ca | 197 | break; |
18ca7dab RK |
198 | } |
199 | ||
0c12fc9b | 200 | if (maybe_ne (c, 0)) |
4789c0ce | 201 | x = gen_rtx_PLUS (mode, x, gen_int_mode (c, mode)); |
18ca7dab RK |
202 | |
203 | if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF) | |
204 | return x; | |
205 | else if (all_constant) | |
38a448ca | 206 | return gen_rtx_CONST (mode, x); |
18ca7dab RK |
207 | else |
208 | return x; | |
209 | } | |
18ca7dab RK |
210 | \f |
211 | /* If X is a sum, return a new sum like X but lacking any constant terms. | |
212 | Add all the removed constant terms into *CONSTPTR. | |
213 | X itself is not altered. The result != X if and only if | |
214 | it is not isomorphic to X. */ | |
215 | ||
216 | rtx | |
502b8322 | 217 | eliminate_constant_term (rtx x, rtx *constptr) |
18ca7dab | 218 | { |
b3694847 | 219 | rtx x0, x1; |
18ca7dab RK |
220 | rtx tem; |
221 | ||
222 | if (GET_CODE (x) != PLUS) | |
223 | return x; | |
224 | ||
225 | /* First handle constants appearing at this level explicitly. */ | |
481683e1 | 226 | if (CONST_INT_P (XEXP (x, 1)) |
01512446 JJ |
227 | && (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr, |
228 | XEXP (x, 1))) != 0 | |
481683e1 | 229 | && CONST_INT_P (tem)) |
18ca7dab RK |
230 | { |
231 | *constptr = tem; | |
232 | return eliminate_constant_term (XEXP (x, 0), constptr); | |
233 | } | |
234 | ||
235 | tem = const0_rtx; | |
236 | x0 = eliminate_constant_term (XEXP (x, 0), &tem); | |
237 | x1 = eliminate_constant_term (XEXP (x, 1), &tem); | |
238 | if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0)) | |
01512446 JJ |
239 | && (tem = simplify_binary_operation (PLUS, GET_MODE (x), |
240 | *constptr, tem)) != 0 | |
481683e1 | 241 | && CONST_INT_P (tem)) |
18ca7dab RK |
242 | { |
243 | *constptr = tem; | |
38a448ca | 244 | return gen_rtx_PLUS (GET_MODE (x), x0, x1); |
18ca7dab RK |
245 | } |
246 | ||
247 | return x; | |
248 | } | |
249 | ||
18ca7dab RK |
250 | \f |
251 | /* Return a copy of X in which all memory references | |
252 | and all constants that involve symbol refs | |
253 | have been replaced with new temporary registers. | |
254 | Also emit code to load the memory locations and constants | |
255 | into those registers. | |
256 | ||
257 | If X contains no such constants or memory references, | |
258 | X itself (not a copy) is returned. | |
259 | ||
260 | If a constant is found in the address that is not a legitimate constant | |
261 | in an insn, it is left alone in the hope that it might be valid in the | |
262 | address. | |
263 | ||
264 | X may contain no arithmetic except addition, subtraction and multiplication. | |
265 | Values returned by expand_expr with 1 for sum_ok fit this constraint. */ | |
266 | ||
267 | static rtx | |
502b8322 | 268 | break_out_memory_refs (rtx x) |
18ca7dab | 269 | { |
3c0cb5de | 270 | if (MEM_P (x) |
cabeca29 | 271 | || (CONSTANT_P (x) && CONSTANT_ADDRESS_P (x) |
18ca7dab | 272 | && GET_MODE (x) != VOIDmode)) |
2cca6e3f | 273 | x = force_reg (GET_MODE (x), x); |
18ca7dab RK |
274 | else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS |
275 | || GET_CODE (x) == MULT) | |
276 | { | |
b3694847 SS |
277 | rtx op0 = break_out_memory_refs (XEXP (x, 0)); |
278 | rtx op1 = break_out_memory_refs (XEXP (x, 1)); | |
2cca6e3f | 279 | |
18ca7dab | 280 | if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1)) |
d4ebfa65 | 281 | x = simplify_gen_binary (GET_CODE (x), GET_MODE (x), op0, op1); |
18ca7dab | 282 | } |
2cca6e3f | 283 | |
18ca7dab RK |
284 | return x; |
285 | } | |
286 | ||
d4ebfa65 BE |
287 | /* Given X, a memory address in address space AS' pointer mode, convert it to |
288 | an address in the address space's address mode, or vice versa (TO_MODE says | |
289 | which way). We take advantage of the fact that pointers are not allowed to | |
290 | overflow by commuting arithmetic operations over conversions so that address | |
7745730f | 291 | arithmetic insns can be used. IN_CONST is true if this conversion is inside |
3d3f9e7e JJ |
292 | a CONST. NO_EMIT is true if no insns should be emitted, and instead |
293 | it should return NULL if it can't be simplified without emitting insns. */ | |
ea534b63 | 294 | |
3d3f9e7e | 295 | rtx |
095a2d76 | 296 | convert_memory_address_addr_space_1 (scalar_int_mode to_mode ATTRIBUTE_UNUSED, |
7745730f | 297 | rtx x, addr_space_t as ATTRIBUTE_UNUSED, |
3d3f9e7e JJ |
298 | bool in_const ATTRIBUTE_UNUSED, |
299 | bool no_emit ATTRIBUTE_UNUSED) | |
ea534b63 | 300 | { |
5ae6cd0d | 301 | #ifndef POINTERS_EXTEND_UNSIGNED |
7c137931 | 302 | gcc_assert (GET_MODE (x) == to_mode || GET_MODE (x) == VOIDmode); |
5ae6cd0d MM |
303 | return x; |
304 | #else /* defined(POINTERS_EXTEND_UNSIGNED) */ | |
095a2d76 | 305 | scalar_int_mode pointer_mode, address_mode, from_mode; |
498b529f | 306 | rtx temp; |
aa0f70e6 | 307 | enum rtx_code code; |
498b529f | 308 | |
5ae6cd0d MM |
309 | /* If X already has the right mode, just return it. */ |
310 | if (GET_MODE (x) == to_mode) | |
311 | return x; | |
312 | ||
d4ebfa65 BE |
313 | pointer_mode = targetm.addr_space.pointer_mode (as); |
314 | address_mode = targetm.addr_space.address_mode (as); | |
315 | from_mode = to_mode == pointer_mode ? address_mode : pointer_mode; | |
5ae6cd0d | 316 | |
0b04ec8c RK |
317 | /* Here we handle some special cases. If none of them apply, fall through |
318 | to the default case. */ | |
ea534b63 RK |
319 | switch (GET_CODE (x)) |
320 | { | |
d8116890 | 321 | CASE_CONST_SCALAR_INT: |
aa0f70e6 SE |
322 | if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)) |
323 | code = TRUNCATE; | |
324 | else if (POINTERS_EXTEND_UNSIGNED < 0) | |
325 | break; | |
326 | else if (POINTERS_EXTEND_UNSIGNED > 0) | |
327 | code = ZERO_EXTEND; | |
328 | else | |
329 | code = SIGN_EXTEND; | |
330 | temp = simplify_unary_operation (code, to_mode, x, from_mode); | |
331 | if (temp) | |
332 | return temp; | |
333 | break; | |
498b529f | 334 | |
d1405722 | 335 | case SUBREG: |
5da4f548 | 336 | if ((SUBREG_PROMOTED_VAR_P (x) || REG_POINTER (SUBREG_REG (x))) |
6dd12198 | 337 | && GET_MODE (SUBREG_REG (x)) == to_mode) |
d1405722 RK |
338 | return SUBREG_REG (x); |
339 | break; | |
340 | ||
ea534b63 | 341 | case LABEL_REF: |
04a121a7 | 342 | temp = gen_rtx_LABEL_REF (to_mode, label_ref_label (x)); |
5da4f548 SE |
343 | LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x); |
344 | return temp; | |
498b529f | 345 | |
ea534b63 | 346 | case SYMBOL_REF: |
ce02ba25 EC |
347 | temp = shallow_copy_rtx (x); |
348 | PUT_MODE (temp, to_mode); | |
5da4f548 | 349 | return temp; |
ea534b63 | 350 | |
498b529f | 351 | case CONST: |
3d3f9e7e JJ |
352 | temp = convert_memory_address_addr_space_1 (to_mode, XEXP (x, 0), as, |
353 | true, no_emit); | |
354 | return temp ? gen_rtx_CONST (to_mode, temp) : temp; | |
ea534b63 | 355 | |
0b04ec8c RK |
356 | case PLUS: |
357 | case MULT: | |
ceeb2cbc AP |
358 | /* For addition we can safely permute the conversion and addition |
359 | operation if one operand is a constant and converting the constant | |
360 | does not change it or if one operand is a constant and we are | |
361 | using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0). | |
17939c98 | 362 | We can always safely permute them if we are making the address |
7745730f AP |
363 | narrower. Inside a CONST RTL, this is safe for both pointers |
364 | zero or sign extended as pointers cannot wrap. */ | |
aa0f70e6 SE |
365 | if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode) |
366 | || (GET_CODE (x) == PLUS | |
481683e1 | 367 | && CONST_INT_P (XEXP (x, 1)) |
7745730f AP |
368 | && ((in_const && POINTERS_EXTEND_UNSIGNED != 0) |
369 | || XEXP (x, 1) == convert_memory_address_addr_space_1 | |
3d3f9e7e JJ |
370 | (to_mode, XEXP (x, 1), as, in_const, |
371 | no_emit) | |
7745730f | 372 | || POINTERS_EXTEND_UNSIGNED < 0))) |
3d3f9e7e JJ |
373 | { |
374 | temp = convert_memory_address_addr_space_1 (to_mode, XEXP (x, 0), | |
375 | as, in_const, no_emit); | |
b88990be JJ |
376 | return (temp ? gen_rtx_fmt_ee (GET_CODE (x), to_mode, |
377 | temp, XEXP (x, 1)) | |
378 | : temp); | |
3d3f9e7e | 379 | } |
38a448ca | 380 | break; |
d9b3eb63 | 381 | |
e8beba1c RS |
382 | case UNSPEC: |
383 | /* Assume that all UNSPECs in a constant address can be converted | |
384 | operand-by-operand. We could add a target hook if some targets | |
385 | require different behavior. */ | |
386 | if (in_const && GET_MODE (x) == from_mode) | |
387 | { | |
388 | unsigned int n = XVECLEN (x, 0); | |
389 | rtvec v = gen_rtvec (n); | |
390 | for (unsigned int i = 0; i < n; ++i) | |
391 | { | |
392 | rtx op = XVECEXP (x, 0, i); | |
393 | if (GET_MODE (op) == from_mode) | |
394 | op = convert_memory_address_addr_space_1 (to_mode, op, as, | |
395 | in_const, no_emit); | |
396 | RTVEC_ELT (v, i) = op; | |
397 | } | |
398 | return gen_rtx_UNSPEC (to_mode, v, XINT (x, 1)); | |
399 | } | |
400 | break; | |
401 | ||
38a448ca RH |
402 | default: |
403 | break; | |
ea534b63 | 404 | } |
0b04ec8c | 405 | |
3d3f9e7e JJ |
406 | if (no_emit) |
407 | return NULL_RTX; | |
408 | ||
0b04ec8c RK |
409 | return convert_modes (to_mode, from_mode, |
410 | x, POINTERS_EXTEND_UNSIGNED); | |
5ae6cd0d | 411 | #endif /* defined(POINTERS_EXTEND_UNSIGNED) */ |
ea534b63 | 412 | } |
7745730f AP |
413 | |
414 | /* Given X, a memory address in address space AS' pointer mode, convert it to | |
415 | an address in the address space's address mode, or vice versa (TO_MODE says | |
416 | which way). We take advantage of the fact that pointers are not allowed to | |
417 | overflow by commuting arithmetic operations over conversions so that address | |
418 | arithmetic insns can be used. */ | |
419 | ||
420 | rtx | |
095a2d76 RS |
421 | convert_memory_address_addr_space (scalar_int_mode to_mode, rtx x, |
422 | addr_space_t as) | |
7745730f | 423 | { |
3d3f9e7e | 424 | return convert_memory_address_addr_space_1 (to_mode, x, as, false, false); |
7745730f | 425 | } |
18ca7dab | 426 | \f |
36566b39 | 427 | |
09e881c9 BE |
428 | /* Return something equivalent to X but valid as a memory address for something |
429 | of mode MODE in the named address space AS. When X is not itself valid, | |
430 | this works by copying X or subexpressions of it into registers. */ | |
18ca7dab RK |
431 | |
432 | rtx | |
ef4bddc2 | 433 | memory_address_addr_space (machine_mode mode, rtx x, addr_space_t as) |
18ca7dab | 434 | { |
b3694847 | 435 | rtx oldx = x; |
095a2d76 | 436 | scalar_int_mode address_mode = targetm.addr_space.address_mode (as); |
18ca7dab | 437 | |
d4ebfa65 | 438 | x = convert_memory_address_addr_space (address_mode, x, as); |
ea534b63 | 439 | |
ba228239 | 440 | /* By passing constant addresses through registers |
18ca7dab | 441 | we get a chance to cse them. */ |
cabeca29 | 442 | if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x)) |
d4ebfa65 | 443 | x = force_reg (address_mode, x); |
18ca7dab | 444 | |
18ca7dab RK |
445 | /* We get better cse by rejecting indirect addressing at this stage. |
446 | Let the combiner create indirect addresses where appropriate. | |
447 | For now, generate the code so that the subexpressions useful to share | |
448 | are visible. But not if cse won't be done! */ | |
18b9ca6f | 449 | else |
18ca7dab | 450 | { |
f8cfc6aa | 451 | if (! cse_not_expected && !REG_P (x)) |
18b9ca6f RK |
452 | x = break_out_memory_refs (x); |
453 | ||
454 | /* At this point, any valid address is accepted. */ | |
09e881c9 | 455 | if (memory_address_addr_space_p (mode, x, as)) |
3de5e93a | 456 | goto done; |
18b9ca6f RK |
457 | |
458 | /* If it was valid before but breaking out memory refs invalidated it, | |
459 | use it the old way. */ | |
09e881c9 | 460 | if (memory_address_addr_space_p (mode, oldx, as)) |
3de5e93a SB |
461 | { |
462 | x = oldx; | |
463 | goto done; | |
464 | } | |
18b9ca6f RK |
465 | |
466 | /* Perform machine-dependent transformations on X | |
467 | in certain cases. This is not necessary since the code | |
468 | below can handle all possible cases, but machine-dependent | |
469 | transformations can make better code. */ | |
506d7b68 | 470 | { |
09e881c9 BE |
471 | rtx orig_x = x; |
472 | x = targetm.addr_space.legitimize_address (x, oldx, mode, as); | |
473 | if (orig_x != x && memory_address_addr_space_p (mode, x, as)) | |
506d7b68 PB |
474 | goto done; |
475 | } | |
18b9ca6f RK |
476 | |
477 | /* PLUS and MULT can appear in special ways | |
478 | as the result of attempts to make an address usable for indexing. | |
479 | Usually they are dealt with by calling force_operand, below. | |
480 | But a sum containing constant terms is special | |
481 | if removing them makes the sum a valid address: | |
482 | then we generate that address in a register | |
483 | and index off of it. We do this because it often makes | |
484 | shorter code, and because the addresses thus generated | |
485 | in registers often become common subexpressions. */ | |
486 | if (GET_CODE (x) == PLUS) | |
487 | { | |
488 | rtx constant_term = const0_rtx; | |
489 | rtx y = eliminate_constant_term (x, &constant_term); | |
490 | if (constant_term == const0_rtx | |
09e881c9 | 491 | || ! memory_address_addr_space_p (mode, y, as)) |
18b9ca6f RK |
492 | x = force_operand (x, NULL_RTX); |
493 | else | |
494 | { | |
38a448ca | 495 | y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term); |
09e881c9 | 496 | if (! memory_address_addr_space_p (mode, y, as)) |
18b9ca6f RK |
497 | x = force_operand (x, NULL_RTX); |
498 | else | |
499 | x = y; | |
500 | } | |
501 | } | |
18ca7dab | 502 | |
e475ed2a | 503 | else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS) |
18b9ca6f | 504 | x = force_operand (x, NULL_RTX); |
18ca7dab | 505 | |
18b9ca6f RK |
506 | /* If we have a register that's an invalid address, |
507 | it must be a hard reg of the wrong class. Copy it to a pseudo. */ | |
f8cfc6aa | 508 | else if (REG_P (x)) |
18b9ca6f RK |
509 | x = copy_to_reg (x); |
510 | ||
511 | /* Last resort: copy the value to a register, since | |
512 | the register is a valid address. */ | |
513 | else | |
d4ebfa65 | 514 | x = force_reg (address_mode, x); |
18ca7dab | 515 | } |
18b9ca6f RK |
516 | |
517 | done: | |
518 | ||
09e881c9 | 519 | gcc_assert (memory_address_addr_space_p (mode, x, as)); |
2cca6e3f RK |
520 | /* If we didn't change the address, we are done. Otherwise, mark |
521 | a reg as a pointer if we have REG or REG + CONST_INT. */ | |
522 | if (oldx == x) | |
523 | return x; | |
f8cfc6aa | 524 | else if (REG_P (x)) |
bdb429a5 | 525 | mark_reg_pointer (x, BITS_PER_UNIT); |
2cca6e3f | 526 | else if (GET_CODE (x) == PLUS |
f8cfc6aa | 527 | && REG_P (XEXP (x, 0)) |
481683e1 | 528 | && CONST_INT_P (XEXP (x, 1))) |
bdb429a5 | 529 | mark_reg_pointer (XEXP (x, 0), BITS_PER_UNIT); |
2cca6e3f | 530 | |
18b9ca6f RK |
531 | /* OLDX may have been the address on a temporary. Update the address |
532 | to indicate that X is now used. */ | |
533 | update_temp_slot_address (oldx, x); | |
534 | ||
18ca7dab RK |
535 | return x; |
536 | } | |
537 | ||
b8105705 EB |
538 | /* Convert a mem ref into one with a valid memory address. |
539 | Pass through anything else unchanged. */ | |
18ca7dab RK |
540 | |
541 | rtx | |
502b8322 | 542 | validize_mem (rtx ref) |
18ca7dab | 543 | { |
3c0cb5de | 544 | if (!MEM_P (ref)) |
18ca7dab | 545 | return ref; |
aacd3885 | 546 | ref = use_anchored_address (ref); |
09e881c9 BE |
547 | if (memory_address_addr_space_p (GET_MODE (ref), XEXP (ref, 0), |
548 | MEM_ADDR_SPACE (ref))) | |
18ca7dab | 549 | return ref; |
792760b9 | 550 | |
b8105705 EB |
551 | /* Don't alter REF itself, since that is probably a stack slot. */ |
552 | return replace_equiv_address (ref, XEXP (ref, 0)); | |
18ca7dab | 553 | } |
aacd3885 RS |
554 | |
555 | /* If X is a memory reference to a member of an object block, try rewriting | |
556 | it to use an anchor instead. Return the new memory reference on success | |
557 | and the old one on failure. */ | |
558 | ||
559 | rtx | |
560 | use_anchored_address (rtx x) | |
561 | { | |
562 | rtx base; | |
563 | HOST_WIDE_INT offset; | |
ef4bddc2 | 564 | machine_mode mode; |
aacd3885 RS |
565 | |
566 | if (!flag_section_anchors) | |
567 | return x; | |
568 | ||
569 | if (!MEM_P (x)) | |
570 | return x; | |
571 | ||
572 | /* Split the address into a base and offset. */ | |
573 | base = XEXP (x, 0); | |
574 | offset = 0; | |
575 | if (GET_CODE (base) == CONST | |
576 | && GET_CODE (XEXP (base, 0)) == PLUS | |
481683e1 | 577 | && CONST_INT_P (XEXP (XEXP (base, 0), 1))) |
aacd3885 RS |
578 | { |
579 | offset += INTVAL (XEXP (XEXP (base, 0), 1)); | |
580 | base = XEXP (XEXP (base, 0), 0); | |
581 | } | |
582 | ||
583 | /* Check whether BASE is suitable for anchors. */ | |
584 | if (GET_CODE (base) != SYMBOL_REF | |
3fa9c136 | 585 | || !SYMBOL_REF_HAS_BLOCK_INFO_P (base) |
aacd3885 | 586 | || SYMBOL_REF_ANCHOR_P (base) |
434aeebb | 587 | || SYMBOL_REF_BLOCK (base) == NULL |
aacd3885 RS |
588 | || !targetm.use_anchors_for_symbol_p (base)) |
589 | return x; | |
590 | ||
591 | /* Decide where BASE is going to be. */ | |
592 | place_block_symbol (base); | |
593 | ||
594 | /* Get the anchor we need to use. */ | |
595 | offset += SYMBOL_REF_BLOCK_OFFSET (base); | |
596 | base = get_section_anchor (SYMBOL_REF_BLOCK (base), offset, | |
597 | SYMBOL_REF_TLS_MODEL (base)); | |
598 | ||
599 | /* Work out the offset from the anchor. */ | |
600 | offset -= SYMBOL_REF_BLOCK_OFFSET (base); | |
601 | ||
602 | /* If we're going to run a CSE pass, force the anchor into a register. | |
603 | We will then be able to reuse registers for several accesses, if the | |
604 | target costs say that that's worthwhile. */ | |
0a81f074 | 605 | mode = GET_MODE (base); |
aacd3885 | 606 | if (!cse_not_expected) |
0a81f074 | 607 | base = force_reg (mode, base); |
aacd3885 | 608 | |
0a81f074 | 609 | return replace_equiv_address (x, plus_constant (mode, base, offset)); |
aacd3885 | 610 | } |
18ca7dab | 611 | \f |
18ca7dab RK |
612 | /* Copy the value or contents of X to a new temp reg and return that reg. */ |
613 | ||
614 | rtx | |
502b8322 | 615 | copy_to_reg (rtx x) |
18ca7dab | 616 | { |
b3694847 | 617 | rtx temp = gen_reg_rtx (GET_MODE (x)); |
d9b3eb63 | 618 | |
18ca7dab | 619 | /* If not an operand, must be an address with PLUS and MULT so |
d9b3eb63 | 620 | do the computation. */ |
18ca7dab RK |
621 | if (! general_operand (x, VOIDmode)) |
622 | x = force_operand (x, temp); | |
d9b3eb63 | 623 | |
18ca7dab RK |
624 | if (x != temp) |
625 | emit_move_insn (temp, x); | |
626 | ||
627 | return temp; | |
628 | } | |
629 | ||
630 | /* Like copy_to_reg but always give the new register mode Pmode | |
631 | in case X is a constant. */ | |
632 | ||
633 | rtx | |
502b8322 | 634 | copy_addr_to_reg (rtx x) |
18ca7dab RK |
635 | { |
636 | return copy_to_mode_reg (Pmode, x); | |
637 | } | |
638 | ||
639 | /* Like copy_to_reg but always give the new register mode MODE | |
640 | in case X is a constant. */ | |
641 | ||
642 | rtx | |
ef4bddc2 | 643 | copy_to_mode_reg (machine_mode mode, rtx x) |
18ca7dab | 644 | { |
b3694847 | 645 | rtx temp = gen_reg_rtx (mode); |
d9b3eb63 | 646 | |
18ca7dab | 647 | /* If not an operand, must be an address with PLUS and MULT so |
d9b3eb63 | 648 | do the computation. */ |
18ca7dab RK |
649 | if (! general_operand (x, VOIDmode)) |
650 | x = force_operand (x, temp); | |
651 | ||
5b0264cb | 652 | gcc_assert (GET_MODE (x) == mode || GET_MODE (x) == VOIDmode); |
18ca7dab RK |
653 | if (x != temp) |
654 | emit_move_insn (temp, x); | |
655 | return temp; | |
656 | } | |
657 | ||
658 | /* Load X into a register if it is not already one. | |
659 | Use mode MODE for the register. | |
660 | X should be valid for mode MODE, but it may be a constant which | |
661 | is valid for all integer modes; that's why caller must specify MODE. | |
662 | ||
663 | The caller must not alter the value in the register we return, | |
664 | since we mark it as a "constant" register. */ | |
665 | ||
666 | rtx | |
ef4bddc2 | 667 | force_reg (machine_mode mode, rtx x) |
18ca7dab | 668 | { |
528a80c1 DM |
669 | rtx temp, set; |
670 | rtx_insn *insn; | |
18ca7dab | 671 | |
f8cfc6aa | 672 | if (REG_P (x)) |
18ca7dab | 673 | return x; |
d9b3eb63 | 674 | |
e3c8ea67 RH |
675 | if (general_operand (x, mode)) |
676 | { | |
677 | temp = gen_reg_rtx (mode); | |
678 | insn = emit_move_insn (temp, x); | |
679 | } | |
680 | else | |
681 | { | |
682 | temp = force_operand (x, NULL_RTX); | |
f8cfc6aa | 683 | if (REG_P (temp)) |
e3c8ea67 RH |
684 | insn = get_last_insn (); |
685 | else | |
686 | { | |
687 | rtx temp2 = gen_reg_rtx (mode); | |
688 | insn = emit_move_insn (temp2, temp); | |
689 | temp = temp2; | |
690 | } | |
691 | } | |
62874575 | 692 | |
18ca7dab | 693 | /* Let optimizers know that TEMP's value never changes |
62874575 RK |
694 | and that X can be substituted for it. Don't get confused |
695 | if INSN set something else (such as a SUBREG of TEMP). */ | |
696 | if (CONSTANT_P (x) | |
697 | && (set = single_set (insn)) != 0 | |
fd7acc30 RS |
698 | && SET_DEST (set) == temp |
699 | && ! rtx_equal_p (x, SET_SRC (set))) | |
3d238248 | 700 | set_unique_reg_note (insn, REG_EQUAL, x); |
e3c8ea67 | 701 | |
4a4f95d9 RH |
702 | /* Let optimizers know that TEMP is a pointer, and if so, the |
703 | known alignment of that pointer. */ | |
704 | { | |
705 | unsigned align = 0; | |
706 | if (GET_CODE (x) == SYMBOL_REF) | |
707 | { | |
708 | align = BITS_PER_UNIT; | |
709 | if (SYMBOL_REF_DECL (x) && DECL_P (SYMBOL_REF_DECL (x))) | |
710 | align = DECL_ALIGN (SYMBOL_REF_DECL (x)); | |
711 | } | |
712 | else if (GET_CODE (x) == LABEL_REF) | |
713 | align = BITS_PER_UNIT; | |
714 | else if (GET_CODE (x) == CONST | |
715 | && GET_CODE (XEXP (x, 0)) == PLUS | |
716 | && GET_CODE (XEXP (XEXP (x, 0), 0)) == SYMBOL_REF | |
481683e1 | 717 | && CONST_INT_P (XEXP (XEXP (x, 0), 1))) |
4a4f95d9 RH |
718 | { |
719 | rtx s = XEXP (XEXP (x, 0), 0); | |
720 | rtx c = XEXP (XEXP (x, 0), 1); | |
721 | unsigned sa, ca; | |
722 | ||
723 | sa = BITS_PER_UNIT; | |
724 | if (SYMBOL_REF_DECL (s) && DECL_P (SYMBOL_REF_DECL (s))) | |
725 | sa = DECL_ALIGN (SYMBOL_REF_DECL (s)); | |
726 | ||
bd95721f RH |
727 | if (INTVAL (c) == 0) |
728 | align = sa; | |
729 | else | |
730 | { | |
731 | ca = ctz_hwi (INTVAL (c)) * BITS_PER_UNIT; | |
732 | align = MIN (sa, ca); | |
733 | } | |
4a4f95d9 RH |
734 | } |
735 | ||
0a317111 | 736 | if (align || (MEM_P (x) && MEM_POINTER (x))) |
4a4f95d9 RH |
737 | mark_reg_pointer (temp, align); |
738 | } | |
739 | ||
18ca7dab RK |
740 | return temp; |
741 | } | |
742 | ||
743 | /* If X is a memory ref, copy its contents to a new temp reg and return | |
744 | that reg. Otherwise, return X. */ | |
745 | ||
746 | rtx | |
502b8322 | 747 | force_not_mem (rtx x) |
18ca7dab | 748 | { |
b3694847 | 749 | rtx temp; |
fe3439b0 | 750 | |
3c0cb5de | 751 | if (!MEM_P (x) || GET_MODE (x) == BLKmode) |
18ca7dab | 752 | return x; |
fe3439b0 | 753 | |
18ca7dab | 754 | temp = gen_reg_rtx (GET_MODE (x)); |
f8ad8d7c ZD |
755 | |
756 | if (MEM_POINTER (x)) | |
757 | REG_POINTER (temp) = 1; | |
758 | ||
18ca7dab RK |
759 | emit_move_insn (temp, x); |
760 | return temp; | |
761 | } | |
762 | ||
763 | /* Copy X to TARGET (if it's nonzero and a reg) | |
764 | or to a new temp reg and return that reg. | |
765 | MODE is the mode to use for X in case it is a constant. */ | |
766 | ||
767 | rtx | |
ef4bddc2 | 768 | copy_to_suggested_reg (rtx x, rtx target, machine_mode mode) |
18ca7dab | 769 | { |
b3694847 | 770 | rtx temp; |
18ca7dab | 771 | |
f8cfc6aa | 772 | if (target && REG_P (target)) |
18ca7dab RK |
773 | temp = target; |
774 | else | |
775 | temp = gen_reg_rtx (mode); | |
776 | ||
777 | emit_move_insn (temp, x); | |
778 | return temp; | |
779 | } | |
780 | \f | |
cde0f3fd | 781 | /* Return the mode to use to pass or return a scalar of TYPE and MODE. |
9ff65789 RK |
782 | PUNSIGNEDP points to the signedness of the type and may be adjusted |
783 | to show what signedness to use on extension operations. | |
784 | ||
cde0f3fd PB |
785 | FOR_RETURN is nonzero if the caller is promoting the return value |
786 | of FNDECL, else it is for promoting args. */ | |
9ff65789 | 787 | |
ef4bddc2 RS |
788 | machine_mode |
789 | promote_function_mode (const_tree type, machine_mode mode, int *punsignedp, | |
cde0f3fd PB |
790 | const_tree funtype, int for_return) |
791 | { | |
5e617be8 AK |
792 | /* Called without a type node for a libcall. */ |
793 | if (type == NULL_TREE) | |
794 | { | |
795 | if (INTEGRAL_MODE_P (mode)) | |
796 | return targetm.calls.promote_function_mode (NULL_TREE, mode, | |
797 | punsignedp, funtype, | |
798 | for_return); | |
799 | else | |
800 | return mode; | |
801 | } | |
802 | ||
cde0f3fd PB |
803 | switch (TREE_CODE (type)) |
804 | { | |
805 | case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE: | |
806 | case REAL_TYPE: case OFFSET_TYPE: case FIXED_POINT_TYPE: | |
807 | case POINTER_TYPE: case REFERENCE_TYPE: | |
808 | return targetm.calls.promote_function_mode (type, mode, punsignedp, funtype, | |
809 | for_return); | |
810 | ||
811 | default: | |
812 | return mode; | |
813 | } | |
814 | } | |
815 | /* Return the mode to use to store a scalar of TYPE and MODE. | |
816 | PUNSIGNEDP points to the signedness of the type and may be adjusted | |
817 | to show what signedness to use on extension operations. */ | |
d4453b7a | 818 | |
ef4bddc2 RS |
819 | machine_mode |
820 | promote_mode (const_tree type ATTRIBUTE_UNUSED, machine_mode mode, | |
b1680483 | 821 | int *punsignedp ATTRIBUTE_UNUSED) |
9ff65789 | 822 | { |
1e3287d0 RG |
823 | #ifdef PROMOTE_MODE |
824 | enum tree_code code; | |
825 | int unsignedp; | |
79d22165 | 826 | scalar_mode smode; |
1e3287d0 RG |
827 | #endif |
828 | ||
5e617be8 AK |
829 | /* For libcalls this is invoked without TYPE from the backends |
830 | TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that | |
831 | case. */ | |
832 | if (type == NULL_TREE) | |
833 | return mode; | |
834 | ||
cde0f3fd PB |
835 | /* FIXME: this is the same logic that was there until GCC 4.4, but we |
836 | probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE | |
837 | is not defined. The affected targets are M32C, S390, SPARC. */ | |
838 | #ifdef PROMOTE_MODE | |
1e3287d0 RG |
839 | code = TREE_CODE (type); |
840 | unsignedp = *punsignedp; | |
9ff65789 | 841 | |
9ff65789 RK |
842 | switch (code) |
843 | { | |
9ff65789 | 844 | case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE: |
325217ed | 845 | case REAL_TYPE: case OFFSET_TYPE: case FIXED_POINT_TYPE: |
79d22165 RS |
846 | /* Values of these types always have scalar mode. */ |
847 | smode = as_a <scalar_mode> (mode); | |
848 | PROMOTE_MODE (smode, unsignedp, type); | |
cde0f3fd | 849 | *punsignedp = unsignedp; |
79d22165 | 850 | return smode; |
9ff65789 | 851 | |
ea534b63 | 852 | #ifdef POINTERS_EXTEND_UNSIGNED |
56a4c9e2 | 853 | case REFERENCE_TYPE: |
9ff65789 | 854 | case POINTER_TYPE: |
cde0f3fd | 855 | *punsignedp = POINTERS_EXTEND_UNSIGNED; |
d4ebfa65 BE |
856 | return targetm.addr_space.address_mode |
857 | (TYPE_ADDR_SPACE (TREE_TYPE (type))); | |
ea534b63 | 858 | #endif |
d9b3eb63 | 859 | |
38a448ca | 860 | default: |
cde0f3fd | 861 | return mode; |
9ff65789 | 862 | } |
cde0f3fd | 863 | #else |
9ff65789 | 864 | return mode; |
cde0f3fd | 865 | #endif |
9ff65789 | 866 | } |
cde0f3fd PB |
867 | |
868 | ||
869 | /* Use one of promote_mode or promote_function_mode to find the promoted | |
870 | mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness | |
871 | of DECL after promotion. */ | |
872 | ||
ef4bddc2 | 873 | machine_mode |
cde0f3fd PB |
874 | promote_decl_mode (const_tree decl, int *punsignedp) |
875 | { | |
876 | tree type = TREE_TYPE (decl); | |
877 | int unsignedp = TYPE_UNSIGNED (type); | |
ef4bddc2 RS |
878 | machine_mode mode = DECL_MODE (decl); |
879 | machine_mode pmode; | |
cde0f3fd | 880 | |
f11a7b6d AO |
881 | if (TREE_CODE (decl) == RESULT_DECL && !DECL_BY_REFERENCE (decl)) |
882 | pmode = promote_function_mode (type, mode, &unsignedp, | |
883 | TREE_TYPE (current_function_decl), 1); | |
884 | else if (TREE_CODE (decl) == RESULT_DECL || TREE_CODE (decl) == PARM_DECL) | |
cde0f3fd | 885 | pmode = promote_function_mode (type, mode, &unsignedp, |
666e3ceb | 886 | TREE_TYPE (current_function_decl), 2); |
cde0f3fd PB |
887 | else |
888 | pmode = promote_mode (type, mode, &unsignedp); | |
889 | ||
890 | if (punsignedp) | |
891 | *punsignedp = unsignedp; | |
892 | return pmode; | |
893 | } | |
894 | ||
1f9ceff1 AO |
895 | /* Return the promoted mode for name. If it is a named SSA_NAME, it |
896 | is the same as promote_decl_mode. Otherwise, it is the promoted | |
897 | mode of a temp decl of same type as the SSA_NAME, if we had created | |
898 | one. */ | |
899 | ||
900 | machine_mode | |
901 | promote_ssa_mode (const_tree name, int *punsignedp) | |
902 | { | |
903 | gcc_assert (TREE_CODE (name) == SSA_NAME); | |
904 | ||
905 | /* Partitions holding parms and results must be promoted as expected | |
e53b6e56 | 906 | by function.cc. */ |
1f9ceff1 AO |
907 | if (SSA_NAME_VAR (name) |
908 | && (TREE_CODE (SSA_NAME_VAR (name)) == PARM_DECL | |
909 | || TREE_CODE (SSA_NAME_VAR (name)) == RESULT_DECL)) | |
f11a7b6d AO |
910 | { |
911 | machine_mode mode = promote_decl_mode (SSA_NAME_VAR (name), punsignedp); | |
912 | if (mode != BLKmode) | |
913 | return mode; | |
914 | } | |
1f9ceff1 AO |
915 | |
916 | tree type = TREE_TYPE (name); | |
917 | int unsignedp = TYPE_UNSIGNED (type); | |
a59b2e42 | 918 | machine_mode pmode = promote_mode (type, TYPE_MODE (type), &unsignedp); |
1f9ceff1 AO |
919 | if (punsignedp) |
920 | *punsignedp = unsignedp; | |
921 | ||
922 | return pmode; | |
923 | } | |
924 | ||
925 | ||
9ff65789 | 926 | \f |
9c582551 | 927 | /* Controls the behavior of {anti_,}adjust_stack. */ |
9a08d230 RH |
928 | static bool suppress_reg_args_size; |
929 | ||
930 | /* A helper for adjust_stack and anti_adjust_stack. */ | |
931 | ||
932 | static void | |
933 | adjust_stack_1 (rtx adjust, bool anti_p) | |
934 | { | |
528a80c1 DM |
935 | rtx temp; |
936 | rtx_insn *insn; | |
9a08d230 | 937 | |
9a08d230 | 938 | /* Hereafter anti_p means subtract_p. */ |
581edfa3 TS |
939 | if (!STACK_GROWS_DOWNWARD) |
940 | anti_p = !anti_p; | |
9a08d230 RH |
941 | |
942 | temp = expand_binop (Pmode, | |
943 | anti_p ? sub_optab : add_optab, | |
944 | stack_pointer_rtx, adjust, stack_pointer_rtx, 0, | |
945 | OPTAB_LIB_WIDEN); | |
946 | ||
947 | if (temp != stack_pointer_rtx) | |
948 | insn = emit_move_insn (stack_pointer_rtx, temp); | |
949 | else | |
950 | { | |
951 | insn = get_last_insn (); | |
952 | temp = single_set (insn); | |
953 | gcc_assert (temp != NULL && SET_DEST (temp) == stack_pointer_rtx); | |
954 | } | |
955 | ||
956 | if (!suppress_reg_args_size) | |
68184180 | 957 | add_args_size_note (insn, stack_pointer_delta); |
9a08d230 RH |
958 | } |
959 | ||
18ca7dab RK |
960 | /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes). |
961 | This pops when ADJUST is positive. ADJUST need not be constant. */ | |
962 | ||
963 | void | |
502b8322 | 964 | adjust_stack (rtx adjust) |
18ca7dab | 965 | { |
18ca7dab RK |
966 | if (adjust == const0_rtx) |
967 | return; | |
968 | ||
1503a7ec JH |
969 | /* We expect all variable sized adjustments to be multiple of |
970 | PREFERRED_STACK_BOUNDARY. */ | |
5284e559 RS |
971 | poly_int64 const_adjust; |
972 | if (poly_int_rtx_p (adjust, &const_adjust)) | |
973 | stack_pointer_delta -= const_adjust; | |
1503a7ec | 974 | |
9a08d230 | 975 | adjust_stack_1 (adjust, false); |
18ca7dab RK |
976 | } |
977 | ||
978 | /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes). | |
979 | This pushes when ADJUST is positive. ADJUST need not be constant. */ | |
980 | ||
981 | void | |
502b8322 | 982 | anti_adjust_stack (rtx adjust) |
18ca7dab | 983 | { |
18ca7dab RK |
984 | if (adjust == const0_rtx) |
985 | return; | |
986 | ||
1503a7ec JH |
987 | /* We expect all variable sized adjustments to be multiple of |
988 | PREFERRED_STACK_BOUNDARY. */ | |
5284e559 RS |
989 | poly_int64 const_adjust; |
990 | if (poly_int_rtx_p (adjust, &const_adjust)) | |
991 | stack_pointer_delta += const_adjust; | |
1503a7ec | 992 | |
9a08d230 | 993 | adjust_stack_1 (adjust, true); |
18ca7dab RK |
994 | } |
995 | ||
996 | /* Round the size of a block to be pushed up to the boundary required | |
997 | by this machine. SIZE is the desired size, which need not be constant. */ | |
998 | ||
4dd9b044 | 999 | static rtx |
502b8322 | 1000 | round_push (rtx size) |
18ca7dab | 1001 | { |
32990d5b | 1002 | rtx align_rtx, alignm1_rtx; |
41ee3204 | 1003 | |
32990d5b JJ |
1004 | if (!SUPPORTS_STACK_ALIGNMENT |
1005 | || crtl->preferred_stack_boundary == MAX_SUPPORTED_STACK_ALIGNMENT) | |
18ca7dab | 1006 | { |
32990d5b JJ |
1007 | int align = crtl->preferred_stack_boundary / BITS_PER_UNIT; |
1008 | ||
1009 | if (align == 1) | |
1010 | return size; | |
1011 | ||
1012 | if (CONST_INT_P (size)) | |
1013 | { | |
1014 | HOST_WIDE_INT new_size = (INTVAL (size) + align - 1) / align * align; | |
41ee3204 | 1015 | |
32990d5b JJ |
1016 | if (INTVAL (size) != new_size) |
1017 | size = GEN_INT (new_size); | |
1018 | return size; | |
1019 | } | |
1020 | ||
1021 | align_rtx = GEN_INT (align); | |
1022 | alignm1_rtx = GEN_INT (align - 1); | |
18ca7dab RK |
1023 | } |
1024 | else | |
1025 | { | |
32990d5b JJ |
1026 | /* If crtl->preferred_stack_boundary might still grow, use |
1027 | virtual_preferred_stack_boundary_rtx instead. This will be | |
1028 | substituted by the right value in vregs pass and optimized | |
1029 | during combine. */ | |
1030 | align_rtx = virtual_preferred_stack_boundary_rtx; | |
0a81f074 RS |
1031 | alignm1_rtx = force_operand (plus_constant (Pmode, align_rtx, -1), |
1032 | NULL_RTX); | |
18ca7dab | 1033 | } |
41ee3204 | 1034 | |
32990d5b JJ |
1035 | /* CEIL_DIV_EXPR needs to worry about the addition overflowing, |
1036 | but we know it can't. So add ourselves and then do | |
1037 | TRUNC_DIV_EXPR. */ | |
1038 | size = expand_binop (Pmode, add_optab, size, alignm1_rtx, | |
1039 | NULL_RTX, 1, OPTAB_LIB_WIDEN); | |
1040 | size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, align_rtx, | |
1041 | NULL_RTX, 1); | |
1042 | size = expand_mult (Pmode, size, align_rtx, NULL_RTX, 1); | |
1043 | ||
18ca7dab RK |
1044 | return size; |
1045 | } | |
1046 | \f | |
59257ff7 RK |
1047 | /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer |
1048 | to a previously-created save area. If no save area has been allocated, | |
1049 | this function will allocate one. If a save area is specified, it | |
9eac0f2a | 1050 | must be of the proper mode. */ |
59257ff7 RK |
1051 | |
1052 | void | |
9eac0f2a | 1053 | emit_stack_save (enum save_level save_level, rtx *psave) |
59257ff7 RK |
1054 | { |
1055 | rtx sa = *psave; | |
1056 | /* The default is that we use a move insn and save in a Pmode object. */ | |
4476e1a0 | 1057 | rtx_insn *(*fcn) (rtx, rtx) = gen_move_insn; |
ef4bddc2 | 1058 | machine_mode mode = STACK_SAVEAREA_MODE (save_level); |
59257ff7 RK |
1059 | |
1060 | /* See if this machine has anything special to do for this kind of save. */ | |
1061 | switch (save_level) | |
1062 | { | |
59257ff7 | 1063 | case SAVE_BLOCK: |
4476e1a0 RS |
1064 | if (targetm.have_save_stack_block ()) |
1065 | fcn = targetm.gen_save_stack_block; | |
59257ff7 | 1066 | break; |
59257ff7 | 1067 | case SAVE_FUNCTION: |
4476e1a0 RS |
1068 | if (targetm.have_save_stack_function ()) |
1069 | fcn = targetm.gen_save_stack_function; | |
59257ff7 | 1070 | break; |
59257ff7 | 1071 | case SAVE_NONLOCAL: |
4476e1a0 RS |
1072 | if (targetm.have_save_stack_nonlocal ()) |
1073 | fcn = targetm.gen_save_stack_nonlocal; | |
59257ff7 | 1074 | break; |
38a448ca RH |
1075 | default: |
1076 | break; | |
59257ff7 RK |
1077 | } |
1078 | ||
1079 | /* If there is no save area and we have to allocate one, do so. Otherwise | |
1080 | verify the save area is the proper mode. */ | |
1081 | ||
1082 | if (sa == 0) | |
1083 | { | |
1084 | if (mode != VOIDmode) | |
1085 | { | |
1086 | if (save_level == SAVE_NONLOCAL) | |
1087 | *psave = sa = assign_stack_local (mode, GET_MODE_SIZE (mode), 0); | |
1088 | else | |
1089 | *psave = sa = gen_reg_rtx (mode); | |
1090 | } | |
1091 | } | |
59257ff7 | 1092 | |
9eac0f2a RH |
1093 | do_pending_stack_adjust (); |
1094 | if (sa != 0) | |
1095 | sa = validize_mem (sa); | |
1096 | emit_insn (fcn (sa, stack_pointer_rtx)); | |
59257ff7 RK |
1097 | } |
1098 | ||
1099 | /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save | |
9eac0f2a | 1100 | area made by emit_stack_save. If it is zero, we have nothing to do. */ |
59257ff7 RK |
1101 | |
1102 | void | |
9eac0f2a | 1103 | emit_stack_restore (enum save_level save_level, rtx sa) |
59257ff7 RK |
1104 | { |
1105 | /* The default is that we use a move insn. */ | |
4476e1a0 | 1106 | rtx_insn *(*fcn) (rtx, rtx) = gen_move_insn; |
59257ff7 | 1107 | |
50025f91 TV |
1108 | /* If stack_realign_drap, the x86 backend emits a prologue that aligns both |
1109 | STACK_POINTER and HARD_FRAME_POINTER. | |
1110 | If stack_realign_fp, the x86 backend emits a prologue that aligns only | |
1111 | STACK_POINTER. This renders the HARD_FRAME_POINTER unusable for accessing | |
1112 | aligned variables, which is reflected in ix86_can_eliminate. | |
1113 | We normally still have the realigned STACK_POINTER that we can use. | |
1114 | But if there is a stack restore still present at reload, it can trigger | |
1115 | mark_not_eliminable for the STACK_POINTER, leaving no way to eliminate | |
1116 | FRAME_POINTER into a hard reg. | |
1117 | To prevent this situation, we force need_drap if we emit a stack | |
1118 | restore. */ | |
1119 | if (SUPPORTS_STACK_ALIGNMENT) | |
1120 | crtl->need_drap = true; | |
1121 | ||
59257ff7 RK |
1122 | /* See if this machine has anything special to do for this kind of save. */ |
1123 | switch (save_level) | |
1124 | { | |
59257ff7 | 1125 | case SAVE_BLOCK: |
4476e1a0 RS |
1126 | if (targetm.have_restore_stack_block ()) |
1127 | fcn = targetm.gen_restore_stack_block; | |
59257ff7 | 1128 | break; |
59257ff7 | 1129 | case SAVE_FUNCTION: |
4476e1a0 RS |
1130 | if (targetm.have_restore_stack_function ()) |
1131 | fcn = targetm.gen_restore_stack_function; | |
59257ff7 | 1132 | break; |
59257ff7 | 1133 | case SAVE_NONLOCAL: |
4476e1a0 RS |
1134 | if (targetm.have_restore_stack_nonlocal ()) |
1135 | fcn = targetm.gen_restore_stack_nonlocal; | |
59257ff7 | 1136 | break; |
38a448ca RH |
1137 | default: |
1138 | break; | |
59257ff7 RK |
1139 | } |
1140 | ||
d072107f | 1141 | if (sa != 0) |
260f91c2 DJ |
1142 | { |
1143 | sa = validize_mem (sa); | |
1144 | /* These clobbers prevent the scheduler from moving | |
1145 | references to variable arrays below the code | |
4b7e68e7 | 1146 | that deletes (pops) the arrays. */ |
c41c1387 RS |
1147 | emit_clobber (gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))); |
1148 | emit_clobber (gen_rtx_MEM (BLKmode, stack_pointer_rtx)); | |
260f91c2 | 1149 | } |
d072107f | 1150 | |
a494ed43 EB |
1151 | discard_pending_stack_adjust (); |
1152 | ||
9eac0f2a | 1153 | emit_insn (fcn (stack_pointer_rtx, sa)); |
59257ff7 | 1154 | } |
6de9cd9a DN |
1155 | |
1156 | /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current | |
d33606c3 EB |
1157 | function. This should be called whenever we allocate or deallocate |
1158 | dynamic stack space. */ | |
6de9cd9a DN |
1159 | |
1160 | void | |
1161 | update_nonlocal_goto_save_area (void) | |
1162 | { | |
1163 | tree t_save; | |
1164 | rtx r_save; | |
1165 | ||
1166 | /* The nonlocal_goto_save_area object is an array of N pointers. The | |
1167 | first one is used for the frame pointer save; the rest are sized by | |
1168 | STACK_SAVEAREA_MODE. Create a reference to array index 1, the first | |
1169 | of the stack save area slots. */ | |
6bbec3e1 L |
1170 | t_save = build4 (ARRAY_REF, |
1171 | TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)), | |
1172 | cfun->nonlocal_goto_save_area, | |
3244e67d | 1173 | integer_one_node, NULL_TREE, NULL_TREE); |
6de9cd9a DN |
1174 | r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE); |
1175 | ||
9eac0f2a | 1176 | emit_stack_save (SAVE_NONLOCAL, &r_save); |
6de9cd9a | 1177 | } |
d33606c3 EB |
1178 | |
1179 | /* Record a new stack level for the current function. This should be called | |
1180 | whenever we allocate or deallocate dynamic stack space. */ | |
1181 | ||
1182 | void | |
1183 | record_new_stack_level (void) | |
1184 | { | |
1185 | /* Record the new stack level for nonlocal gotos. */ | |
1186 | if (cfun->nonlocal_goto_save_area) | |
1187 | update_nonlocal_goto_save_area (); | |
1188 | ||
1189 | /* Record the new stack level for SJLJ exceptions. */ | |
1190 | if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ) | |
1191 | update_sjlj_context (); | |
1192 | } | |
0358d788 | 1193 | |
7072df0a | 1194 | /* Return an rtx doing runtime alignment to REQUIRED_ALIGN on TARGET. */ |
0358d788 RL |
1195 | |
1196 | rtx | |
7072df0a DV |
1197 | align_dynamic_address (rtx target, unsigned required_align) |
1198 | { | |
1199 | /* CEIL_DIV_EXPR needs to worry about the addition overflowing, | |
1200 | but we know it can't. So add ourselves and then do | |
1201 | TRUNC_DIV_EXPR. */ | |
1202 | target = expand_binop (Pmode, add_optab, target, | |
1203 | gen_int_mode (required_align / BITS_PER_UNIT - 1, | |
1204 | Pmode), | |
1205 | NULL_RTX, 1, OPTAB_LIB_WIDEN); | |
1206 | target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target, | |
1207 | gen_int_mode (required_align / BITS_PER_UNIT, | |
1208 | Pmode), | |
1209 | NULL_RTX, 1); | |
1210 | target = expand_mult (Pmode, target, | |
1211 | gen_int_mode (required_align / BITS_PER_UNIT, | |
1212 | Pmode), | |
1213 | NULL_RTX, 1); | |
18ca7dab | 1214 | |
7072df0a DV |
1215 | return target; |
1216 | } | |
18ca7dab | 1217 | |
7072df0a DV |
1218 | /* Return an rtx through *PSIZE, representing the size of an area of memory to |
1219 | be dynamically pushed on the stack. | |
1220 | ||
1221 | *PSIZE is an rtx representing the size of the area. | |
091ad0b9 | 1222 | |
3a42502d | 1223 | SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This |
7072df0a | 1224 | parameter may be zero. If so, a proper value will be extracted |
3a42502d RH |
1225 | from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed. |
1226 | ||
1227 | REQUIRED_ALIGN is the alignment (in bits) required for the region | |
1228 | of memory. | |
d3c12306 | 1229 | |
7072df0a DV |
1230 | If PSTACK_USAGE_SIZE is not NULL it points to a value that is increased for |
1231 | the additional size returned. */ | |
1232 | void | |
1233 | get_dynamic_stack_size (rtx *psize, unsigned size_align, | |
1234 | unsigned required_align, | |
1235 | HOST_WIDE_INT *pstack_usage_size) | |
18ca7dab | 1236 | { |
7072df0a | 1237 | rtx size = *psize; |
d3c12306 | 1238 | |
18ca7dab RK |
1239 | /* Ensure the size is in the proper mode. */ |
1240 | if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode) | |
1241 | size = convert_to_mode (Pmode, size, 1); | |
1242 | ||
3a42502d RH |
1243 | if (CONST_INT_P (size)) |
1244 | { | |
1245 | unsigned HOST_WIDE_INT lsb; | |
1246 | ||
1247 | lsb = INTVAL (size); | |
1248 | lsb &= -lsb; | |
1249 | ||
1250 | /* Watch out for overflow truncating to "unsigned". */ | |
1251 | if (lsb > UINT_MAX / BITS_PER_UNIT) | |
1252 | size_align = 1u << (HOST_BITS_PER_INT - 1); | |
1253 | else | |
1254 | size_align = (unsigned)lsb * BITS_PER_UNIT; | |
1255 | } | |
1256 | else if (size_align < BITS_PER_UNIT) | |
1257 | size_align = BITS_PER_UNIT; | |
1258 | ||
34831f3e RH |
1259 | /* We can't attempt to minimize alignment necessary, because we don't |
1260 | know the final value of preferred_stack_boundary yet while executing | |
1261 | this code. */ | |
1262 | if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY) | |
1263 | crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY; | |
1264 | ||
18ca7dab | 1265 | /* We will need to ensure that the address we return is aligned to |
4fc0c9c8 | 1266 | REQUIRED_ALIGN. At this point in the compilation, we don't always |
e53b6e56 | 1267 | know the final value of the STACK_DYNAMIC_OFFSET used in function.cc |
4fc0c9c8 DV |
1268 | (it might depend on the size of the outgoing parameter lists, for |
1269 | example), so we must preventively align the value. We leave space | |
1270 | in SIZE for the hole that might result from the alignment operation. */ | |
1ecad98e | 1271 | |
b9f92c0b EB |
1272 | unsigned known_align = REGNO_POINTER_ALIGN (VIRTUAL_STACK_DYNAMIC_REGNUM); |
1273 | if (known_align == 0) | |
1274 | known_align = BITS_PER_UNIT; | |
1275 | if (required_align > known_align) | |
ae85ad3a | 1276 | { |
b9f92c0b | 1277 | unsigned extra = (required_align - known_align) / BITS_PER_UNIT; |
ae85ad3a WD |
1278 | size = plus_constant (Pmode, size, extra); |
1279 | size = force_operand (size, NULL_RTX); | |
b9f92c0b EB |
1280 | if (size_align > known_align) |
1281 | size_align = known_align; | |
ae85ad3a WD |
1282 | |
1283 | if (flag_stack_usage_info && pstack_usage_size) | |
1284 | *pstack_usage_size += extra; | |
1285 | } | |
1d9d04f8 | 1286 | |
18ca7dab | 1287 | /* Round the size to a multiple of the required stack alignment. |
1135a133 | 1288 | Since the stack is presumed to be rounded before this allocation, |
18ca7dab RK |
1289 | this will maintain the required alignment. |
1290 | ||
1291 | If the stack grows downward, we could save an insn by subtracting | |
1292 | SIZE from the stack pointer and then aligning the stack pointer. | |
1293 | The problem with this is that the stack pointer may be unaligned | |
1294 | between the execution of the subtraction and alignment insns and | |
1295 | some machines do not allow this. Even on those that do, some | |
1296 | signal handlers malfunction if a signal should occur between those | |
1297 | insns. Since this is an extremely rare event, we have no reliable | |
1298 | way of knowing which systems have this problem. So we avoid even | |
1299 | momentarily mis-aligning the stack. */ | |
3a42502d | 1300 | if (size_align % MAX_SUPPORTED_STACK_ALIGNMENT != 0) |
d3c12306 EB |
1301 | { |
1302 | size = round_push (size); | |
18ca7dab | 1303 | |
7072df0a | 1304 | if (flag_stack_usage_info && pstack_usage_size) |
d3c12306 | 1305 | { |
32990d5b | 1306 | int align = crtl->preferred_stack_boundary / BITS_PER_UNIT; |
7072df0a DV |
1307 | *pstack_usage_size = |
1308 | (*pstack_usage_size + align - 1) / align * align; | |
d3c12306 EB |
1309 | } |
1310 | } | |
1311 | ||
7072df0a DV |
1312 | *psize = size; |
1313 | } | |
1314 | ||
8c1dd970 JL |
1315 | /* Return the number of bytes to "protect" on the stack for -fstack-check. |
1316 | ||
f569026a EB |
1317 | "protect" in the context of -fstack-check means how many bytes we need |
1318 | to always ensure are available on the stack; as a consequence, this is | |
1319 | also how many bytes are first skipped when probing the stack. | |
8c1dd970 JL |
1320 | |
1321 | On some targets we want to reuse the -fstack-check prologue support | |
1322 | to give a degree of protection against stack clashing style attacks. | |
1323 | ||
1324 | In that scenario we do not want to skip bytes before probing as that | |
1325 | would render the stack clash protections useless. | |
1326 | ||
f569026a EB |
1327 | So we never use STACK_CHECK_PROTECT directly. Instead we indirectly |
1328 | use it through this helper, which allows to provide different values | |
1329 | for -fstack-check and -fstack-clash-protection. */ | |
1330 | ||
8c1dd970 JL |
1331 | HOST_WIDE_INT |
1332 | get_stack_check_protect (void) | |
1333 | { | |
1334 | if (flag_stack_clash_protection) | |
1335 | return 0; | |
f569026a | 1336 | |
8c1dd970 JL |
1337 | return STACK_CHECK_PROTECT; |
1338 | } | |
1339 | ||
7072df0a DV |
1340 | /* Return an rtx representing the address of an area of memory dynamically |
1341 | pushed on the stack. | |
1342 | ||
1343 | Any required stack pointer alignment is preserved. | |
1344 | ||
1345 | SIZE is an rtx representing the size of the area. | |
1346 | ||
1347 | SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This | |
1348 | parameter may be zero. If so, a proper value will be extracted | |
1349 | from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed. | |
1350 | ||
1351 | REQUIRED_ALIGN is the alignment (in bits) required for the region | |
1352 | of memory. | |
1353 | ||
9e878cf1 EB |
1354 | MAX_SIZE is an upper bound for SIZE, if SIZE is not constant, or -1 if |
1355 | no such upper bound is known. | |
1356 | ||
7072df0a DV |
1357 | If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the |
1358 | stack space allocated by the generated code cannot be added with itself | |
1359 | in the course of the execution of the function. It is always safe to | |
1360 | pass FALSE here and the following criterion is sufficient in order to | |
1361 | pass TRUE: every path in the CFG that starts at the allocation point and | |
1362 | loops to it executes the associated deallocation code. */ | |
1363 | ||
1364 | rtx | |
1365 | allocate_dynamic_stack_space (rtx size, unsigned size_align, | |
9e878cf1 EB |
1366 | unsigned required_align, |
1367 | HOST_WIDE_INT max_size, | |
1368 | bool cannot_accumulate) | |
7072df0a DV |
1369 | { |
1370 | HOST_WIDE_INT stack_usage_size = -1; | |
1371 | rtx_code_label *final_label; | |
1372 | rtx final_target, target; | |
1373 | ||
1374 | /* If we're asking for zero bytes, it doesn't matter what we point | |
1375 | to since we can't dereference it. But return a reasonable | |
1376 | address anyway. */ | |
1377 | if (size == const0_rtx) | |
1378 | return virtual_stack_dynamic_rtx; | |
1379 | ||
1380 | /* Otherwise, show we're calling alloca or equivalent. */ | |
1381 | cfun->calls_alloca = 1; | |
1382 | ||
1383 | /* If stack usage info is requested, look into the size we are passed. | |
1384 | We need to do so this early to avoid the obfuscation that may be | |
1385 | introduced later by the various alignment operations. */ | |
1386 | if (flag_stack_usage_info) | |
1387 | { | |
1388 | if (CONST_INT_P (size)) | |
1389 | stack_usage_size = INTVAL (size); | |
1390 | else if (REG_P (size)) | |
1391 | { | |
1392 | /* Look into the last emitted insn and see if we can deduce | |
1393 | something for the register. */ | |
1394 | rtx_insn *insn; | |
1395 | rtx set, note; | |
1396 | insn = get_last_insn (); | |
1397 | if ((set = single_set (insn)) && rtx_equal_p (SET_DEST (set), size)) | |
1398 | { | |
1399 | if (CONST_INT_P (SET_SRC (set))) | |
1400 | stack_usage_size = INTVAL (SET_SRC (set)); | |
1401 | else if ((note = find_reg_equal_equiv_note (insn)) | |
1402 | && CONST_INT_P (XEXP (note, 0))) | |
1403 | stack_usage_size = INTVAL (XEXP (note, 0)); | |
1404 | } | |
1405 | } | |
1406 | ||
9e878cf1 EB |
1407 | /* If the size is not constant, try the maximum size. */ |
1408 | if (stack_usage_size < 0) | |
1409 | stack_usage_size = max_size; | |
1410 | ||
1411 | /* If the size is still not constant, we can't say anything. */ | |
1412 | if (stack_usage_size < 0) | |
7072df0a DV |
1413 | { |
1414 | current_function_has_unbounded_dynamic_stack_size = 1; | |
1415 | stack_usage_size = 0; | |
1416 | } | |
1417 | } | |
1418 | ||
1419 | get_dynamic_stack_size (&size, size_align, required_align, &stack_usage_size); | |
1420 | ||
3a42502d | 1421 | target = gen_reg_rtx (Pmode); |
7458026b | 1422 | |
d3c12306 EB |
1423 | /* The size is supposed to be fully adjusted at this point so record it |
1424 | if stack usage info is requested. */ | |
a11e0df4 | 1425 | if (flag_stack_usage_info) |
d3c12306 EB |
1426 | { |
1427 | current_function_dynamic_stack_size += stack_usage_size; | |
1428 | ||
1429 | /* ??? This is gross but the only safe stance in the absence | |
1430 | of stack usage oriented flow analysis. */ | |
1431 | if (!cannot_accumulate) | |
1432 | current_function_has_unbounded_dynamic_stack_size = 1; | |
1433 | } | |
18ca7dab | 1434 | |
1c84b798 ILT |
1435 | do_pending_stack_adjust (); |
1436 | ||
528a80c1 | 1437 | final_label = NULL; |
7458026b ILT |
1438 | final_target = NULL_RTX; |
1439 | ||
1440 | /* If we are splitting the stack, we need to ask the backend whether | |
1441 | there is enough room on the current stack. If there isn't, or if | |
1442 | the backend doesn't know how to tell is, then we need to call a | |
1443 | function to allocate memory in some other way. This memory will | |
1444 | be released when we release the current stack segment. The | |
1445 | effect is that stack allocation becomes less efficient, but at | |
1446 | least it doesn't cause a stack overflow. */ | |
1447 | if (flag_split_stack) | |
1448 | { | |
528a80c1 DM |
1449 | rtx_code_label *available_label; |
1450 | rtx ask, space, func; | |
7458026b | 1451 | |
528a80c1 | 1452 | available_label = NULL; |
7458026b | 1453 | |
10169a8b | 1454 | if (targetm.have_split_stack_space_check ()) |
7458026b ILT |
1455 | { |
1456 | available_label = gen_label_rtx (); | |
1457 | ||
1458 | /* This instruction will branch to AVAILABLE_LABEL if there | |
1459 | are SIZE bytes available on the stack. */ | |
10169a8b RS |
1460 | emit_insn (targetm.gen_split_stack_space_check |
1461 | (size, available_label)); | |
7458026b | 1462 | } |
7458026b | 1463 | |
c3928dde | 1464 | /* The __morestack_allocate_stack_space function will allocate |
c070a3b9 ILT |
1465 | memory using malloc. If the alignment of the memory returned |
1466 | by malloc does not meet REQUIRED_ALIGN, we increase SIZE to | |
1467 | make sure we allocate enough space. */ | |
1468 | if (MALLOC_ABI_ALIGNMENT >= required_align) | |
1469 | ask = size; | |
1470 | else | |
4fc0c9c8 DV |
1471 | ask = expand_binop (Pmode, add_optab, size, |
1472 | gen_int_mode (required_align / BITS_PER_UNIT - 1, | |
1473 | Pmode), | |
1474 | NULL_RTX, 1, OPTAB_LIB_WIDEN); | |
c3928dde | 1475 | |
7458026b ILT |
1476 | func = init_one_libfunc ("__morestack_allocate_stack_space"); |
1477 | ||
1478 | space = emit_library_call_value (func, target, LCT_NORMAL, Pmode, | |
db69559b | 1479 | ask, Pmode); |
7458026b ILT |
1480 | |
1481 | if (available_label == NULL_RTX) | |
1482 | return space; | |
1483 | ||
1484 | final_target = gen_reg_rtx (Pmode); | |
7458026b ILT |
1485 | |
1486 | emit_move_insn (final_target, space); | |
1487 | ||
1488 | final_label = gen_label_rtx (); | |
1489 | emit_jump (final_label); | |
1490 | ||
1491 | emit_label (available_label); | |
1492 | } | |
1493 | ||
1503a7ec | 1494 | /* We ought to be called always on the toplevel and stack ought to be aligned |
a1f300c0 | 1495 | properly. */ |
a20c5714 RS |
1496 | gcc_assert (multiple_p (stack_pointer_delta, |
1497 | PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)); | |
1503a7ec | 1498 | |
d809253a EB |
1499 | /* If needed, check that we have the required amount of stack. Take into |
1500 | account what has already been checked. */ | |
1501 | if (STACK_CHECK_MOVING_SP) | |
1502 | ; | |
1503 | else if (flag_stack_check == GENERIC_STACK_CHECK) | |
b38f3813 EB |
1504 | probe_stack_range (STACK_OLD_CHECK_PROTECT + STACK_CHECK_MAX_FRAME_SIZE, |
1505 | size); | |
1506 | else if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK) | |
8c1dd970 | 1507 | probe_stack_range (get_stack_check_protect (), size); |
edff2491 | 1508 | |
efec771a RH |
1509 | /* Don't let anti_adjust_stack emit notes. */ |
1510 | suppress_reg_args_size = true; | |
1511 | ||
18ca7dab RK |
1512 | /* Perform the required allocation from the stack. Some systems do |
1513 | this differently than simply incrementing/decrementing from the | |
38a448ca | 1514 | stack pointer, such as acquiring the space by calling malloc(). */ |
10169a8b | 1515 | if (targetm.have_allocate_stack ()) |
18ca7dab | 1516 | { |
99b1c316 | 1517 | class expand_operand ops[2]; |
4b6c1672 RK |
1518 | /* We don't have to check against the predicate for operand 0 since |
1519 | TARGET is known to be a pseudo of the proper mode, which must | |
a5c7d693 RS |
1520 | be valid for the operand. */ |
1521 | create_fixed_operand (&ops[0], target); | |
1522 | create_convert_operand_to (&ops[1], size, STACK_SIZE_MODE, true); | |
10169a8b | 1523 | expand_insn (targetm.code_for_allocate_stack, 2, ops); |
18ca7dab RK |
1524 | } |
1525 | else | |
ea534b63 | 1526 | { |
a20c5714 | 1527 | poly_int64 saved_stack_pointer_delta; |
32990d5b | 1528 | |
581edfa3 TS |
1529 | if (!STACK_GROWS_DOWNWARD) |
1530 | emit_move_insn (target, virtual_stack_dynamic_rtx); | |
a157febd GK |
1531 | |
1532 | /* Check stack bounds if necessary. */ | |
e3b5732b | 1533 | if (crtl->limit_stack) |
a157febd GK |
1534 | { |
1535 | rtx available; | |
528a80c1 | 1536 | rtx_code_label *space_available = gen_label_rtx (); |
581edfa3 TS |
1537 | if (STACK_GROWS_DOWNWARD) |
1538 | available = expand_binop (Pmode, sub_optab, | |
1539 | stack_pointer_rtx, stack_limit_rtx, | |
1540 | NULL_RTX, 1, OPTAB_WIDEN); | |
1541 | else | |
1542 | available = expand_binop (Pmode, sub_optab, | |
1543 | stack_limit_rtx, stack_pointer_rtx, | |
1544 | NULL_RTX, 1, OPTAB_WIDEN); | |
1545 | ||
a157febd | 1546 | emit_cmp_and_jump_insns (available, size, GEU, NULL_RTX, Pmode, 1, |
a06ef755 | 1547 | space_available); |
eb6f47fb RS |
1548 | if (targetm.have_trap ()) |
1549 | emit_insn (targetm.gen_trap ()); | |
a157febd | 1550 | else |
a157febd GK |
1551 | error ("stack limits not supported on this target"); |
1552 | emit_barrier (); | |
1553 | emit_label (space_available); | |
1554 | } | |
1555 | ||
32990d5b | 1556 | saved_stack_pointer_delta = stack_pointer_delta; |
9a08d230 | 1557 | |
f569026a EB |
1558 | /* If stack checking or stack clash protection is requested, |
1559 | then probe the stack while allocating space from it. */ | |
d809253a | 1560 | if (flag_stack_check && STACK_CHECK_MOVING_SP) |
c35af30f | 1561 | anti_adjust_stack_and_probe (size, false); |
8c1dd970 JL |
1562 | else if (flag_stack_clash_protection) |
1563 | anti_adjust_stack_and_probe_stack_clash (size); | |
d809253a EB |
1564 | else |
1565 | anti_adjust_stack (size); | |
9a08d230 | 1566 | |
32990d5b JJ |
1567 | /* Even if size is constant, don't modify stack_pointer_delta. |
1568 | The constant size alloca should preserve | |
1569 | crtl->preferred_stack_boundary alignment. */ | |
1570 | stack_pointer_delta = saved_stack_pointer_delta; | |
d5457140 | 1571 | |
581edfa3 TS |
1572 | if (STACK_GROWS_DOWNWARD) |
1573 | emit_move_insn (target, virtual_stack_dynamic_rtx); | |
38a448ca | 1574 | } |
18ca7dab | 1575 | |
efec771a RH |
1576 | suppress_reg_args_size = false; |
1577 | ||
3a42502d RH |
1578 | /* Finish up the split stack handling. */ |
1579 | if (final_label != NULL_RTX) | |
1580 | { | |
1581 | gcc_assert (flag_split_stack); | |
1582 | emit_move_insn (final_target, target); | |
1583 | emit_label (final_label); | |
1584 | target = final_target; | |
1585 | } | |
1586 | ||
7072df0a | 1587 | target = align_dynamic_address (target, required_align); |
d9b3eb63 | 1588 | |
3a42502d RH |
1589 | /* Now that we've committed to a return value, mark its alignment. */ |
1590 | mark_reg_pointer (target, required_align); | |
1591 | ||
d33606c3 EB |
1592 | /* Record the new stack level. */ |
1593 | record_new_stack_level (); | |
15fc0026 | 1594 | |
18ca7dab RK |
1595 | return target; |
1596 | } | |
7072df0a DV |
1597 | |
1598 | /* Return an rtx representing the address of an area of memory already | |
1599 | statically pushed onto the stack in the virtual stack vars area. (It is | |
1600 | assumed that the area is allocated in the function prologue.) | |
1601 | ||
1602 | Any required stack pointer alignment is preserved. | |
1603 | ||
1604 | OFFSET is the offset of the area into the virtual stack vars area. | |
1605 | ||
1606 | REQUIRED_ALIGN is the alignment (in bits) required for the region | |
0854b584 MM |
1607 | of memory. |
1608 | ||
1609 | BASE is the rtx of the base of this virtual stack vars area. | |
1610 | The only time this is not `virtual_stack_vars_rtx` is when tagging pointers | |
1611 | on the stack. */ | |
7072df0a DV |
1612 | |
1613 | rtx | |
0854b584 | 1614 | get_dynamic_stack_base (poly_int64 offset, unsigned required_align, rtx base) |
7072df0a DV |
1615 | { |
1616 | rtx target; | |
1617 | ||
1618 | if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY) | |
1619 | crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY; | |
1620 | ||
1621 | target = gen_reg_rtx (Pmode); | |
0854b584 | 1622 | emit_move_insn (target, base); |
7072df0a DV |
1623 | target = expand_binop (Pmode, add_optab, target, |
1624 | gen_int_mode (offset, Pmode), | |
1625 | NULL_RTX, 1, OPTAB_LIB_WIDEN); | |
1626 | target = align_dynamic_address (target, required_align); | |
1627 | ||
1628 | /* Now that we've committed to a return value, mark its alignment. */ | |
1629 | mark_reg_pointer (target, required_align); | |
1630 | ||
1631 | return target; | |
1632 | } | |
18ca7dab | 1633 | \f |
d9b3eb63 | 1634 | /* A front end may want to override GCC's stack checking by providing a |
14a774a9 RK |
1635 | run-time routine to call to check the stack, so provide a mechanism for |
1636 | calling that routine. */ | |
1637 | ||
e2500fed | 1638 | static GTY(()) rtx stack_check_libfunc; |
14a774a9 RK |
1639 | |
1640 | void | |
d477d1fe | 1641 | set_stack_check_libfunc (const char *libfunc_name) |
14a774a9 | 1642 | { |
d477d1fe SB |
1643 | gcc_assert (stack_check_libfunc == NULL_RTX); |
1644 | stack_check_libfunc = gen_rtx_SYMBOL_REF (Pmode, libfunc_name); | |
97909f80 EB |
1645 | tree ptype |
1646 | = Pmode == ptr_mode | |
1647 | ? ptr_type_node | |
1648 | : lang_hooks.types.type_for_mode (Pmode, 1); | |
1649 | tree ftype | |
1650 | = build_function_type_list (void_type_node, ptype, NULL_TREE); | |
3cf3da88 | 1651 | tree decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, |
97909f80 | 1652 | get_identifier (libfunc_name), ftype); |
3cf3da88 EB |
1653 | DECL_EXTERNAL (decl) = 1; |
1654 | SET_SYMBOL_REF_DECL (stack_check_libfunc, decl); | |
14a774a9 RK |
1655 | } |
1656 | \f | |
edff2491 RK |
1657 | /* Emit one stack probe at ADDRESS, an address within the stack. */ |
1658 | ||
260c8ba3 | 1659 | void |
502b8322 | 1660 | emit_stack_probe (rtx address) |
edff2491 | 1661 | { |
10169a8b | 1662 | if (targetm.have_probe_stack_address ()) |
5c35bc3e | 1663 | { |
99b1c316 | 1664 | class expand_operand ops[1]; |
5c35bc3e KT |
1665 | insn_code icode = targetm.code_for_probe_stack_address; |
1666 | create_address_operand (ops, address); | |
1667 | maybe_legitimize_operands (icode, 0, 1, ops); | |
1668 | expand_insn (icode, 1, ops); | |
1669 | } | |
7b84aac0 | 1670 | else |
7b84aac0 EB |
1671 | { |
1672 | rtx memref = gen_rtx_MEM (word_mode, address); | |
edff2491 | 1673 | |
7b84aac0 | 1674 | MEM_VOLATILE_P (memref) = 1; |
5c35bc3e | 1675 | memref = validize_mem (memref); |
edff2491 | 1676 | |
7b84aac0 | 1677 | /* See if we have an insn to probe the stack. */ |
10169a8b | 1678 | if (targetm.have_probe_stack ()) |
5c35bc3e | 1679 | emit_insn (targetm.gen_probe_stack (memref)); |
7b84aac0 | 1680 | else |
5c35bc3e | 1681 | emit_move_insn (memref, const0_rtx); |
7b84aac0 | 1682 | } |
edff2491 RK |
1683 | } |
1684 | ||
d9b3eb63 | 1685 | /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive. |
d809253a EB |
1686 | FIRST is a constant and size is a Pmode RTX. These are offsets from |
1687 | the current stack pointer. STACK_GROWS_DOWNWARD says whether to add | |
1688 | or subtract them from the stack pointer. */ | |
1689 | ||
1690 | #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP) | |
edff2491 | 1691 | |
62f9f30b | 1692 | #if STACK_GROWS_DOWNWARD |
edff2491 | 1693 | #define STACK_GROW_OP MINUS |
d809253a EB |
1694 | #define STACK_GROW_OPTAB sub_optab |
1695 | #define STACK_GROW_OFF(off) -(off) | |
edff2491 RK |
1696 | #else |
1697 | #define STACK_GROW_OP PLUS | |
d809253a EB |
1698 | #define STACK_GROW_OPTAB add_optab |
1699 | #define STACK_GROW_OFF(off) (off) | |
edff2491 RK |
1700 | #endif |
1701 | ||
1702 | void | |
502b8322 | 1703 | probe_stack_range (HOST_WIDE_INT first, rtx size) |
edff2491 | 1704 | { |
4b6c1672 RK |
1705 | /* First ensure SIZE is Pmode. */ |
1706 | if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode) | |
1707 | size = convert_to_mode (Pmode, size, 1); | |
1708 | ||
d809253a EB |
1709 | /* Next see if we have a function to check the stack. */ |
1710 | if (stack_check_libfunc) | |
f5f5363f | 1711 | { |
d809253a | 1712 | rtx addr = memory_address (Pmode, |
2b3aadfc RH |
1713 | gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, |
1714 | stack_pointer_rtx, | |
0a81f074 RS |
1715 | plus_constant (Pmode, |
1716 | size, first))); | |
db69559b RS |
1717 | emit_library_call (stack_check_libfunc, LCT_THROW, VOIDmode, |
1718 | addr, Pmode); | |
f5f5363f | 1719 | } |
14a774a9 | 1720 | |
d809253a | 1721 | /* Next see if we have an insn to check the stack. */ |
10169a8b | 1722 | else if (targetm.have_check_stack ()) |
edff2491 | 1723 | { |
99b1c316 | 1724 | class expand_operand ops[1]; |
d809253a EB |
1725 | rtx addr = memory_address (Pmode, |
1726 | gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, | |
1727 | stack_pointer_rtx, | |
0a81f074 RS |
1728 | plus_constant (Pmode, |
1729 | size, first))); | |
d6a6a07a | 1730 | bool success; |
a5c7d693 | 1731 | create_input_operand (&ops[0], addr, Pmode); |
10169a8b | 1732 | success = maybe_expand_insn (targetm.code_for_check_stack, 1, ops); |
d6a6a07a | 1733 | gcc_assert (success); |
edff2491 | 1734 | } |
edff2491 | 1735 | |
d809253a EB |
1736 | /* Otherwise we have to generate explicit probes. If we have a constant |
1737 | small number of them to generate, that's the easy case. */ | |
1738 | else if (CONST_INT_P (size) && INTVAL (size) < 7 * PROBE_INTERVAL) | |
edff2491 | 1739 | { |
d809253a EB |
1740 | HOST_WIDE_INT isize = INTVAL (size), i; |
1741 | rtx addr; | |
1742 | ||
1743 | /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until | |
1744 | it exceeds SIZE. If only one probe is needed, this will not | |
1745 | generate any code. Then probe at FIRST + SIZE. */ | |
1746 | for (i = PROBE_INTERVAL; i < isize; i += PROBE_INTERVAL) | |
1747 | { | |
1748 | addr = memory_address (Pmode, | |
0a81f074 | 1749 | plus_constant (Pmode, stack_pointer_rtx, |
d809253a EB |
1750 | STACK_GROW_OFF (first + i))); |
1751 | emit_stack_probe (addr); | |
1752 | } | |
1753 | ||
1754 | addr = memory_address (Pmode, | |
0a81f074 | 1755 | plus_constant (Pmode, stack_pointer_rtx, |
d809253a EB |
1756 | STACK_GROW_OFF (first + isize))); |
1757 | emit_stack_probe (addr); | |
edff2491 RK |
1758 | } |
1759 | ||
d809253a EB |
1760 | /* In the variable case, do the same as above, but in a loop. Note that we |
1761 | must be extra careful with variables wrapping around because we might be | |
1762 | at the very top (or the very bottom) of the address space and we have to | |
1763 | be able to handle this case properly; in particular, we use an equality | |
1764 | test for the loop condition. */ | |
edff2491 RK |
1765 | else |
1766 | { | |
d809253a | 1767 | rtx rounded_size, rounded_size_op, test_addr, last_addr, temp; |
528a80c1 DM |
1768 | rtx_code_label *loop_lab = gen_label_rtx (); |
1769 | rtx_code_label *end_lab = gen_label_rtx (); | |
edff2491 | 1770 | |
d809253a EB |
1771 | /* Step 1: round SIZE to the previous multiple of the interval. */ |
1772 | ||
1773 | /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */ | |
1774 | rounded_size | |
69a59f0f RS |
1775 | = simplify_gen_binary (AND, Pmode, size, |
1776 | gen_int_mode (-PROBE_INTERVAL, Pmode)); | |
d809253a EB |
1777 | rounded_size_op = force_operand (rounded_size, NULL_RTX); |
1778 | ||
1779 | ||
1780 | /* Step 2: compute initial and final value of the loop counter. */ | |
1781 | ||
1782 | /* TEST_ADDR = SP + FIRST. */ | |
1783 | test_addr = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, | |
1784 | stack_pointer_rtx, | |
4789c0ce RS |
1785 | gen_int_mode (first, Pmode)), |
1786 | NULL_RTX); | |
d809253a EB |
1787 | |
1788 | /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */ | |
1789 | last_addr = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, | |
1790 | test_addr, | |
1791 | rounded_size_op), NULL_RTX); | |
1792 | ||
1793 | ||
1794 | /* Step 3: the loop | |
1795 | ||
1796 | while (TEST_ADDR != LAST_ADDR) | |
1797 | { | |
1798 | TEST_ADDR = TEST_ADDR + PROBE_INTERVAL | |
1799 | probe at TEST_ADDR | |
1800 | } | |
1801 | ||
1802 | probes at FIRST + N * PROBE_INTERVAL for values of N from 1 | |
1803 | until it is equal to ROUNDED_SIZE. */ | |
edff2491 RK |
1804 | |
1805 | emit_label (loop_lab); | |
edff2491 | 1806 | |
d809253a EB |
1807 | /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */ |
1808 | emit_cmp_and_jump_insns (test_addr, last_addr, EQ, NULL_RTX, Pmode, 1, | |
1809 | end_lab); | |
1810 | ||
1811 | /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */ | |
1812 | temp = expand_binop (Pmode, STACK_GROW_OPTAB, test_addr, | |
2f1cd2eb | 1813 | gen_int_mode (PROBE_INTERVAL, Pmode), test_addr, |
edff2491 | 1814 | 1, OPTAB_WIDEN); |
edff2491 | 1815 | |
5b0264cb | 1816 | gcc_assert (temp == test_addr); |
edff2491 | 1817 | |
d809253a EB |
1818 | /* Probe at TEST_ADDR. */ |
1819 | emit_stack_probe (test_addr); | |
1820 | ||
1821 | emit_jump (loop_lab); | |
1822 | ||
edff2491 RK |
1823 | emit_label (end_lab); |
1824 | ||
d809253a EB |
1825 | |
1826 | /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time | |
1827 | that SIZE is equal to ROUNDED_SIZE. */ | |
1828 | ||
1829 | /* TEMP = SIZE - ROUNDED_SIZE. */ | |
1830 | temp = simplify_gen_binary (MINUS, Pmode, size, rounded_size); | |
1831 | if (temp != const0_rtx) | |
1832 | { | |
1833 | rtx addr; | |
1834 | ||
32990d5b | 1835 | if (CONST_INT_P (temp)) |
d809253a EB |
1836 | { |
1837 | /* Use [base + disp} addressing mode if supported. */ | |
1838 | HOST_WIDE_INT offset = INTVAL (temp); | |
1839 | addr = memory_address (Pmode, | |
0a81f074 | 1840 | plus_constant (Pmode, last_addr, |
d809253a EB |
1841 | STACK_GROW_OFF (offset))); |
1842 | } | |
1843 | else | |
1844 | { | |
1845 | /* Manual CSE if the difference is not known at compile-time. */ | |
1846 | temp = gen_rtx_MINUS (Pmode, size, rounded_size_op); | |
1847 | addr = memory_address (Pmode, | |
1848 | gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, | |
1849 | last_addr, temp)); | |
1850 | } | |
1851 | ||
1852 | emit_stack_probe (addr); | |
1853 | } | |
edff2491 | 1854 | } |
eabcc725 EB |
1855 | |
1856 | /* Make sure nothing is scheduled before we are done. */ | |
1857 | emit_insn (gen_blockage ()); | |
edff2491 | 1858 | } |
d809253a | 1859 | |
8c1dd970 JL |
1860 | /* Compute parameters for stack clash probing a dynamic stack |
1861 | allocation of SIZE bytes. | |
1862 | ||
1863 | We compute ROUNDED_SIZE, LAST_ADDR, RESIDUAL and PROBE_INTERVAL. | |
1864 | ||
1865 | Additionally we conditionally dump the type of probing that will | |
1866 | be needed given the values computed. */ | |
1867 | ||
1868 | void | |
1869 | compute_stack_clash_protection_loop_data (rtx *rounded_size, rtx *last_addr, | |
1870 | rtx *residual, | |
1871 | HOST_WIDE_INT *probe_interval, | |
1872 | rtx size) | |
1873 | { | |
1874 | /* Round SIZE down to STACK_CLASH_PROTECTION_PROBE_INTERVAL */ | |
1875 | *probe_interval | |
028d4092 | 1876 | = 1 << param_stack_clash_protection_probe_interval; |
8c1dd970 JL |
1877 | *rounded_size = simplify_gen_binary (AND, Pmode, size, |
1878 | GEN_INT (-*probe_interval)); | |
1879 | ||
1880 | /* Compute the value of the stack pointer for the last iteration. | |
1881 | It's just SP + ROUNDED_SIZE. */ | |
1882 | rtx rounded_size_op = force_operand (*rounded_size, NULL_RTX); | |
1883 | *last_addr = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, | |
1884 | stack_pointer_rtx, | |
1885 | rounded_size_op), | |
1886 | NULL_RTX); | |
1887 | ||
1888 | /* Compute any residuals not allocated by the loop above. Residuals | |
1889 | are just the ROUNDED_SIZE - SIZE. */ | |
1890 | *residual = simplify_gen_binary (MINUS, Pmode, size, *rounded_size); | |
1891 | ||
1892 | /* Dump key information to make writing tests easy. */ | |
1893 | if (dump_file) | |
1894 | { | |
1895 | if (*rounded_size == CONST0_RTX (Pmode)) | |
1896 | fprintf (dump_file, | |
1897 | "Stack clash skipped dynamic allocation and probing loop.\n"); | |
94c23e39 | 1898 | else if (CONST_INT_P (*rounded_size) |
8c1dd970 JL |
1899 | && INTVAL (*rounded_size) <= 4 * *probe_interval) |
1900 | fprintf (dump_file, | |
1901 | "Stack clash dynamic allocation and probing inline.\n"); | |
94c23e39 | 1902 | else if (CONST_INT_P (*rounded_size)) |
8c1dd970 JL |
1903 | fprintf (dump_file, |
1904 | "Stack clash dynamic allocation and probing in " | |
1905 | "rotated loop.\n"); | |
1906 | else | |
1907 | fprintf (dump_file, | |
1908 | "Stack clash dynamic allocation and probing in loop.\n"); | |
1909 | ||
1910 | if (*residual != CONST0_RTX (Pmode)) | |
1911 | fprintf (dump_file, | |
1912 | "Stack clash dynamic allocation and probing residuals.\n"); | |
1913 | else | |
1914 | fprintf (dump_file, | |
1915 | "Stack clash skipped dynamic allocation and " | |
1916 | "probing residuals.\n"); | |
1917 | } | |
1918 | } | |
1919 | ||
1920 | /* Emit the start of an allocate/probe loop for stack | |
1921 | clash protection. | |
1922 | ||
1923 | LOOP_LAB and END_LAB are returned for use when we emit the | |
1924 | end of the loop. | |
1925 | ||
1926 | LAST addr is the value for SP which stops the loop. */ | |
1927 | void | |
1928 | emit_stack_clash_protection_probe_loop_start (rtx *loop_lab, | |
1929 | rtx *end_lab, | |
1930 | rtx last_addr, | |
1931 | bool rotated) | |
1932 | { | |
1933 | /* Essentially we want to emit any setup code, the top of loop | |
1934 | label and the comparison at the top of the loop. */ | |
1935 | *loop_lab = gen_label_rtx (); | |
1936 | *end_lab = gen_label_rtx (); | |
1937 | ||
1938 | emit_label (*loop_lab); | |
1939 | if (!rotated) | |
1940 | emit_cmp_and_jump_insns (stack_pointer_rtx, last_addr, EQ, NULL_RTX, | |
1941 | Pmode, 1, *end_lab); | |
1942 | } | |
1943 | ||
1944 | /* Emit the end of a stack clash probing loop. | |
1945 | ||
1946 | This consists of just the jump back to LOOP_LAB and | |
1947 | emitting END_LOOP after the loop. */ | |
1948 | ||
1949 | void | |
1950 | emit_stack_clash_protection_probe_loop_end (rtx loop_lab, rtx end_loop, | |
1951 | rtx last_addr, bool rotated) | |
1952 | { | |
1953 | if (rotated) | |
1954 | emit_cmp_and_jump_insns (stack_pointer_rtx, last_addr, NE, NULL_RTX, | |
1955 | Pmode, 1, loop_lab); | |
1956 | else | |
1957 | emit_jump (loop_lab); | |
1958 | ||
1959 | emit_label (end_loop); | |
1960 | ||
1961 | } | |
1962 | ||
1963 | /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes) | |
1964 | while probing it. This pushes when SIZE is positive. SIZE need not | |
1965 | be constant. | |
1966 | ||
1967 | This is subtly different than anti_adjust_stack_and_probe to try and | |
1968 | prevent stack-clash attacks | |
1969 | ||
1970 | 1. It must assume no knowledge of the probing state, any allocation | |
1971 | must probe. | |
1972 | ||
1973 | Consider the case of a 1 byte alloca in a loop. If the sum of the | |
1974 | allocations is large, then this could be used to jump the guard if | |
1975 | probes were not emitted. | |
1976 | ||
1977 | 2. It never skips probes, whereas anti_adjust_stack_and_probe will | |
f569026a EB |
1978 | skip the probe on the first PROBE_INTERVAL on the assumption it |
1979 | was already done in the prologue and in previous allocations. | |
8c1dd970 JL |
1980 | |
1981 | 3. It only allocates and probes SIZE bytes, it does not need to | |
1982 | allocate/probe beyond that because this probing style does not | |
1983 | guarantee signal handling capability if the guard is hit. */ | |
1984 | ||
d3e5bae1 | 1985 | void |
8c1dd970 JL |
1986 | anti_adjust_stack_and_probe_stack_clash (rtx size) |
1987 | { | |
1988 | /* First ensure SIZE is Pmode. */ | |
1989 | if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode) | |
1990 | size = convert_to_mode (Pmode, size, 1); | |
1991 | ||
1992 | /* We can get here with a constant size on some targets. */ | |
1993 | rtx rounded_size, last_addr, residual; | |
2c25083e TC |
1994 | HOST_WIDE_INT probe_interval, probe_range; |
1995 | bool target_probe_range_p = false; | |
8c1dd970 JL |
1996 | compute_stack_clash_protection_loop_data (&rounded_size, &last_addr, |
1997 | &residual, &probe_interval, size); | |
1998 | ||
2c25083e TC |
1999 | /* Get the back-end specific probe ranges. */ |
2000 | probe_range = targetm.stack_clash_protection_alloca_probe_range (); | |
2001 | target_probe_range_p = probe_range != 0; | |
2002 | gcc_assert (probe_range >= 0); | |
2003 | ||
2004 | /* If no back-end specific range defined, default to the top of the newly | |
2005 | allocated range. */ | |
2006 | if (probe_range == 0) | |
2007 | probe_range = probe_interval - GET_MODE_SIZE (word_mode); | |
2008 | ||
8c1dd970 JL |
2009 | if (rounded_size != CONST0_RTX (Pmode)) |
2010 | { | |
94c23e39 JL |
2011 | if (CONST_INT_P (rounded_size) |
2012 | && INTVAL (rounded_size) <= 4 * probe_interval) | |
8c1dd970 JL |
2013 | { |
2014 | for (HOST_WIDE_INT i = 0; | |
2015 | i < INTVAL (rounded_size); | |
2016 | i += probe_interval) | |
2017 | { | |
2018 | anti_adjust_stack (GEN_INT (probe_interval)); | |
8c1dd970 JL |
2019 | /* The prologue does not probe residuals. Thus the offset |
2020 | here to probe just beyond what the prologue had already | |
2021 | allocated. */ | |
2022 | emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx, | |
2c25083e TC |
2023 | probe_range)); |
2024 | ||
8c1dd970 JL |
2025 | emit_insn (gen_blockage ()); |
2026 | } | |
2027 | } | |
2028 | else | |
2029 | { | |
2030 | rtx loop_lab, end_loop; | |
94c23e39 | 2031 | bool rotate_loop = CONST_INT_P (rounded_size); |
8c1dd970 JL |
2032 | emit_stack_clash_protection_probe_loop_start (&loop_lab, &end_loop, |
2033 | last_addr, rotate_loop); | |
2034 | ||
2035 | anti_adjust_stack (GEN_INT (probe_interval)); | |
2036 | ||
2037 | /* The prologue does not probe residuals. Thus the offset here | |
2c25083e TC |
2038 | to probe just beyond what the prologue had already |
2039 | allocated. */ | |
8c1dd970 | 2040 | emit_stack_probe (plus_constant (Pmode, stack_pointer_rtx, |
2c25083e | 2041 | probe_range)); |
8c1dd970 JL |
2042 | |
2043 | emit_stack_clash_protection_probe_loop_end (loop_lab, end_loop, | |
2044 | last_addr, rotate_loop); | |
2045 | emit_insn (gen_blockage ()); | |
2046 | } | |
2047 | } | |
2048 | ||
2049 | if (residual != CONST0_RTX (Pmode)) | |
2050 | { | |
86aa0691 JL |
2051 | rtx label = NULL_RTX; |
2052 | /* RESIDUAL could be zero at runtime and in that case *sp could | |
2053 | hold live data. Furthermore, we do not want to probe into the | |
2054 | red zone. | |
2055 | ||
2c25083e TC |
2056 | If TARGET_PROBE_RANGE_P then the target has promised it's safe to |
2057 | probe at offset 0. In which case we no longer have to check for | |
2058 | RESIDUAL == 0. However we still need to probe at the right offset | |
2059 | when RESIDUAL > PROBE_RANGE, in which case we probe at PROBE_RANGE. | |
2060 | ||
2061 | If !TARGET_PROBE_RANGE_P then go ahead and just guard the probe at *sp | |
2062 | on RESIDUAL != 0 at runtime if RESIDUAL is not a compile time constant. | |
2063 | */ | |
2064 | anti_adjust_stack (residual); | |
2065 | ||
86aa0691 JL |
2066 | if (!CONST_INT_P (residual)) |
2067 | { | |
2068 | label = gen_label_rtx (); | |
2c25083e TC |
2069 | rtx_code op = target_probe_range_p ? LT : EQ; |
2070 | rtx probe_cmp_value = target_probe_range_p | |
2071 | ? gen_rtx_CONST_INT (GET_MODE (residual), probe_range) | |
2072 | : CONST0_RTX (GET_MODE (residual)); | |
86aa0691 | 2073 | |
2c25083e TC |
2074 | if (target_probe_range_p) |
2075 | emit_stack_probe (stack_pointer_rtx); | |
8c1dd970 | 2076 | |
2c25083e TC |
2077 | emit_cmp_and_jump_insns (residual, probe_cmp_value, |
2078 | op, NULL_RTX, Pmode, 1, label); | |
2079 | } | |
2a6fc987 | 2080 | |
2c25083e TC |
2081 | rtx x = NULL_RTX; |
2082 | ||
2083 | /* If RESIDUAL isn't a constant and TARGET_PROBE_RANGE_P then we probe up | |
2084 | by the ABI defined safe value. */ | |
2085 | if (!CONST_INT_P (residual) && target_probe_range_p) | |
2086 | x = GEN_INT (probe_range); | |
2087 | /* If RESIDUAL is a constant but smaller than the ABI defined safe value, | |
2088 | we still want to probe up, but the safest amount if a word. */ | |
2089 | else if (target_probe_range_p) | |
8c1dd970 | 2090 | { |
2c25083e TC |
2091 | if (INTVAL (residual) <= probe_range) |
2092 | x = GEN_INT (GET_MODE_SIZE (word_mode)); | |
2093 | else | |
2094 | x = GEN_INT (probe_range); | |
8c1dd970 | 2095 | } |
2c25083e TC |
2096 | else |
2097 | /* If nothing else, probe at the top of the new allocation. */ | |
2098 | x = plus_constant (Pmode, residual, -GET_MODE_SIZE (word_mode)); | |
2099 | ||
2100 | emit_stack_probe (gen_rtx_PLUS (Pmode, stack_pointer_rtx, x)); | |
86aa0691 | 2101 | |
86aa0691 | 2102 | emit_insn (gen_blockage ()); |
2c25083e TC |
2103 | if (!CONST_INT_P (residual)) |
2104 | emit_label (label); | |
8c1dd970 JL |
2105 | } |
2106 | } | |
2107 | ||
2108 | ||
c35af30f EB |
2109 | /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes) |
2110 | while probing it. This pushes when SIZE is positive. SIZE need not | |
2111 | be constant. If ADJUST_BACK is true, adjust back the stack pointer | |
2112 | by plus SIZE at the end. */ | |
d809253a | 2113 | |
c35af30f EB |
2114 | void |
2115 | anti_adjust_stack_and_probe (rtx size, bool adjust_back) | |
d809253a | 2116 | { |
c35af30f EB |
2117 | /* We skip the probe for the first interval + a small dope of 4 words and |
2118 | probe that many bytes past the specified size to maintain a protection | |
2119 | area at the botton of the stack. */ | |
d809253a EB |
2120 | const int dope = 4 * UNITS_PER_WORD; |
2121 | ||
2122 | /* First ensure SIZE is Pmode. */ | |
2123 | if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode) | |
2124 | size = convert_to_mode (Pmode, size, 1); | |
2125 | ||
2126 | /* If we have a constant small number of probes to generate, that's the | |
2127 | easy case. */ | |
32990d5b | 2128 | if (CONST_INT_P (size) && INTVAL (size) < 7 * PROBE_INTERVAL) |
d809253a EB |
2129 | { |
2130 | HOST_WIDE_INT isize = INTVAL (size), i; | |
2131 | bool first_probe = true; | |
2132 | ||
260c8ba3 | 2133 | /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for |
d809253a EB |
2134 | values of N from 1 until it exceeds SIZE. If only one probe is |
2135 | needed, this will not generate any code. Then adjust and probe | |
2136 | to PROBE_INTERVAL + SIZE. */ | |
2137 | for (i = PROBE_INTERVAL; i < isize; i += PROBE_INTERVAL) | |
2138 | { | |
2139 | if (first_probe) | |
2140 | { | |
2141 | anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL + dope)); | |
2142 | first_probe = false; | |
2143 | } | |
2144 | else | |
2145 | anti_adjust_stack (GEN_INT (PROBE_INTERVAL)); | |
2146 | emit_stack_probe (stack_pointer_rtx); | |
2147 | } | |
2148 | ||
2149 | if (first_probe) | |
0a81f074 | 2150 | anti_adjust_stack (plus_constant (Pmode, size, PROBE_INTERVAL + dope)); |
d809253a | 2151 | else |
0a81f074 | 2152 | anti_adjust_stack (plus_constant (Pmode, size, PROBE_INTERVAL - i)); |
d809253a EB |
2153 | emit_stack_probe (stack_pointer_rtx); |
2154 | } | |
2155 | ||
2156 | /* In the variable case, do the same as above, but in a loop. Note that we | |
2157 | must be extra careful with variables wrapping around because we might be | |
2158 | at the very top (or the very bottom) of the address space and we have to | |
2159 | be able to handle this case properly; in particular, we use an equality | |
2160 | test for the loop condition. */ | |
2161 | else | |
2162 | { | |
2163 | rtx rounded_size, rounded_size_op, last_addr, temp; | |
528a80c1 DM |
2164 | rtx_code_label *loop_lab = gen_label_rtx (); |
2165 | rtx_code_label *end_lab = gen_label_rtx (); | |
d809253a EB |
2166 | |
2167 | ||
2168 | /* Step 1: round SIZE to the previous multiple of the interval. */ | |
2169 | ||
2170 | /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */ | |
2171 | rounded_size | |
69a59f0f RS |
2172 | = simplify_gen_binary (AND, Pmode, size, |
2173 | gen_int_mode (-PROBE_INTERVAL, Pmode)); | |
d809253a EB |
2174 | rounded_size_op = force_operand (rounded_size, NULL_RTX); |
2175 | ||
2176 | ||
2177 | /* Step 2: compute initial and final value of the loop counter. */ | |
2178 | ||
2179 | /* SP = SP_0 + PROBE_INTERVAL. */ | |
2180 | anti_adjust_stack (GEN_INT (PROBE_INTERVAL + dope)); | |
2181 | ||
2182 | /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */ | |
2183 | last_addr = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode, | |
2184 | stack_pointer_rtx, | |
2185 | rounded_size_op), NULL_RTX); | |
2186 | ||
2187 | ||
2188 | /* Step 3: the loop | |
2189 | ||
260c8ba3 EB |
2190 | while (SP != LAST_ADDR) |
2191 | { | |
2192 | SP = SP + PROBE_INTERVAL | |
2193 | probe at SP | |
2194 | } | |
d809253a | 2195 | |
260c8ba3 | 2196 | adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for |
d809253a EB |
2197 | values of N from 1 until it is equal to ROUNDED_SIZE. */ |
2198 | ||
2199 | emit_label (loop_lab); | |
2200 | ||
2201 | /* Jump to END_LAB if SP == LAST_ADDR. */ | |
2202 | emit_cmp_and_jump_insns (stack_pointer_rtx, last_addr, EQ, NULL_RTX, | |
2203 | Pmode, 1, end_lab); | |
2204 | ||
2205 | /* SP = SP + PROBE_INTERVAL and probe at SP. */ | |
2206 | anti_adjust_stack (GEN_INT (PROBE_INTERVAL)); | |
2207 | emit_stack_probe (stack_pointer_rtx); | |
2208 | ||
2209 | emit_jump (loop_lab); | |
2210 | ||
2211 | emit_label (end_lab); | |
2212 | ||
2213 | ||
260c8ba3 | 2214 | /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot |
d809253a EB |
2215 | assert at compile-time that SIZE is equal to ROUNDED_SIZE. */ |
2216 | ||
2217 | /* TEMP = SIZE - ROUNDED_SIZE. */ | |
2218 | temp = simplify_gen_binary (MINUS, Pmode, size, rounded_size); | |
2219 | if (temp != const0_rtx) | |
2220 | { | |
2221 | /* Manual CSE if the difference is not known at compile-time. */ | |
2222 | if (GET_CODE (temp) != CONST_INT) | |
2223 | temp = gen_rtx_MINUS (Pmode, size, rounded_size_op); | |
2224 | anti_adjust_stack (temp); | |
2225 | emit_stack_probe (stack_pointer_rtx); | |
2226 | } | |
2227 | } | |
2228 | ||
c35af30f EB |
2229 | /* Adjust back and account for the additional first interval. */ |
2230 | if (adjust_back) | |
0a81f074 | 2231 | adjust_stack (plus_constant (Pmode, size, PROBE_INTERVAL + dope)); |
c35af30f EB |
2232 | else |
2233 | adjust_stack (GEN_INT (PROBE_INTERVAL + dope)); | |
d809253a EB |
2234 | } |
2235 | ||
18ca7dab RK |
2236 | /* Return an rtx representing the register or memory location |
2237 | in which a scalar value of data type VALTYPE | |
2238 | was returned by a function call to function FUNC. | |
1d636cc6 RG |
2239 | FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise |
2240 | function is known, otherwise 0. | |
4dc07bd7 JJ |
2241 | OUTGOING is 1 if on a machine with register windows this function |
2242 | should return the register in which the function will put its result | |
30f7a378 | 2243 | and 0 otherwise. */ |
18ca7dab RK |
2244 | |
2245 | rtx | |
586de218 | 2246 | hard_function_value (const_tree valtype, const_tree func, const_tree fntype, |
502b8322 | 2247 | int outgoing ATTRIBUTE_UNUSED) |
18ca7dab | 2248 | { |
4dc07bd7 | 2249 | rtx val; |
770ae6cc | 2250 | |
1d636cc6 | 2251 | val = targetm.calls.function_value (valtype, func ? func : fntype, outgoing); |
770ae6cc | 2252 | |
f8cfc6aa | 2253 | if (REG_P (val) |
e1a4071f JL |
2254 | && GET_MODE (val) == BLKmode) |
2255 | { | |
974aedcc | 2256 | unsigned HOST_WIDE_INT bytes = arg_int_size_in_bytes (valtype); |
59b51186 | 2257 | opt_scalar_int_mode tmpmode; |
770ae6cc | 2258 | |
d9b3eb63 | 2259 | /* int_size_in_bytes can return -1. We don't need a check here |
535a42b1 NS |
2260 | since the value of bytes will then be large enough that no |
2261 | mode will match anyway. */ | |
d9b3eb63 | 2262 | |
c94843d2 | 2263 | FOR_EACH_MODE_IN_CLASS (tmpmode, MODE_INT) |
0fb7aeda KH |
2264 | { |
2265 | /* Have we found a large enough mode? */ | |
59b51186 | 2266 | if (GET_MODE_SIZE (tmpmode.require ()) >= bytes) |
0fb7aeda KH |
2267 | break; |
2268 | } | |
e1a4071f | 2269 | |
59b51186 | 2270 | PUT_MODE (val, tmpmode.require ()); |
d9b3eb63 | 2271 | } |
e1a4071f | 2272 | return val; |
18ca7dab RK |
2273 | } |
2274 | ||
2275 | /* Return an rtx representing the register or memory location | |
2276 | in which a scalar value of mode MODE was returned by a library call. */ | |
2277 | ||
2278 | rtx | |
ef4bddc2 | 2279 | hard_libcall_value (machine_mode mode, rtx fun) |
18ca7dab | 2280 | { |
390b17c2 | 2281 | return targetm.calls.libcall_value (mode, fun); |
18ca7dab | 2282 | } |
0c5e217d RS |
2283 | |
2284 | /* Look up the tree code for a given rtx code | |
5c88ea94 | 2285 | to provide the arithmetic operation for real_arithmetic. |
0c5e217d RS |
2286 | The function returns an int because the caller may not know |
2287 | what `enum tree_code' means. */ | |
2288 | ||
2289 | int | |
502b8322 | 2290 | rtx_to_tree_code (enum rtx_code code) |
0c5e217d RS |
2291 | { |
2292 | enum tree_code tcode; | |
2293 | ||
2294 | switch (code) | |
2295 | { | |
2296 | case PLUS: | |
2297 | tcode = PLUS_EXPR; | |
2298 | break; | |
2299 | case MINUS: | |
2300 | tcode = MINUS_EXPR; | |
2301 | break; | |
2302 | case MULT: | |
2303 | tcode = MULT_EXPR; | |
2304 | break; | |
2305 | case DIV: | |
2306 | tcode = RDIV_EXPR; | |
2307 | break; | |
2308 | case SMIN: | |
2309 | tcode = MIN_EXPR; | |
2310 | break; | |
2311 | case SMAX: | |
2312 | tcode = MAX_EXPR; | |
2313 | break; | |
2314 | default: | |
2315 | tcode = LAST_AND_UNUSED_TREE_CODE; | |
2316 | break; | |
2317 | } | |
2318 | return ((int) tcode); | |
2319 | } | |
e2500fed GK |
2320 | |
2321 | #include "gt-explow.h" |