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18ca7dab 1/* Subroutines for manipulating rtx's in semantically interesting ways.
ef58a523 2 Copyright (C) 1987, 1991, 1994, 1995, 1996, 1997, 1998,
71d59383
RS
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
4 Free Software Foundation, Inc.
18ca7dab 5
1322177d 6This file is part of GCC.
18ca7dab 7
1322177d
LB
8GCC is free software; you can redistribute it and/or modify it under
9the terms of the GNU General Public License as published by the Free
10Software Foundation; either version 2, or (at your option) any later
11version.
18ca7dab 12
1322177d
LB
13GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14WARRANTY; without even the implied warranty of MERCHANTABILITY or
15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16for more details.
18ca7dab
RK
17
18You should have received a copy of the GNU General Public License
1322177d 19along with GCC; see the file COPYING. If not, write to the Free
366ccddb
KC
20Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
2102110-1301, USA. */
18ca7dab
RK
22
23
24#include "config.h"
670ee920 25#include "system.h"
4977bab6
ZW
26#include "coretypes.h"
27#include "tm.h"
01198c2f 28#include "toplev.h"
18ca7dab
RK
29#include "rtl.h"
30#include "tree.h"
6baf1cc8 31#include "tm_p.h"
18ca7dab 32#include "flags.h"
49ad7cfa 33#include "function.h"
18ca7dab 34#include "expr.h"
e78d8e51 35#include "optabs.h"
18ca7dab
RK
36#include "hard-reg-set.h"
37#include "insn-config.h"
1d974ca7 38#include "ggc.h"
18ca7dab 39#include "recog.h"
a77a9a18 40#include "langhooks.h"
1d636cc6 41#include "target.h"
aacd3885 42#include "output.h"
18ca7dab 43
502b8322
AJ
44static rtx break_out_memory_refs (rtx);
45static void emit_stack_probe (rtx);
7e4ce834
RH
46
47
48/* Truncate and perhaps sign-extend C as appropriate for MODE. */
49
50HOST_WIDE_INT
502b8322 51trunc_int_for_mode (HOST_WIDE_INT c, enum machine_mode mode)
7e4ce834
RH
52{
53 int width = GET_MODE_BITSIZE (mode);
54
71012d97 55 /* You want to truncate to a _what_? */
5b0264cb 56 gcc_assert (SCALAR_INT_MODE_P (mode));
71012d97 57
1f3f36d1
RH
58 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
59 if (mode == BImode)
60 return c & 1 ? STORE_FLAG_VALUE : 0;
61
5b0d91c3
AO
62 /* Sign-extend for the requested mode. */
63
64 if (width < HOST_BITS_PER_WIDE_INT)
65 {
66 HOST_WIDE_INT sign = 1;
67 sign <<= width - 1;
68 c &= (sign << 1) - 1;
69 c ^= sign;
70 c -= sign;
71 }
7e4ce834
RH
72
73 return c;
74}
75
3e95a7cb 76/* Return an rtx for the sum of X and the integer C. */
18ca7dab
RK
77
78rtx
3e95a7cb 79plus_constant (rtx x, HOST_WIDE_INT c)
18ca7dab 80{
b3694847 81 RTX_CODE code;
17ab7c59 82 rtx y;
b3694847
SS
83 enum machine_mode mode;
84 rtx tem;
18ca7dab
RK
85 int all_constant = 0;
86
87 if (c == 0)
88 return x;
89
90 restart:
91
92 code = GET_CODE (x);
93 mode = GET_MODE (x);
17ab7c59
RK
94 y = x;
95
18ca7dab
RK
96 switch (code)
97 {
98 case CONST_INT:
b1ec3c92 99 return GEN_INT (INTVAL (x) + c);
18ca7dab
RK
100
101 case CONST_DOUBLE:
102 {
f9e158c3 103 unsigned HOST_WIDE_INT l1 = CONST_DOUBLE_LOW (x);
b1ec3c92 104 HOST_WIDE_INT h1 = CONST_DOUBLE_HIGH (x);
f9e158c3 105 unsigned HOST_WIDE_INT l2 = c;
b1ec3c92 106 HOST_WIDE_INT h2 = c < 0 ? ~0 : 0;
f9e158c3
JM
107 unsigned HOST_WIDE_INT lv;
108 HOST_WIDE_INT hv;
18ca7dab
RK
109
110 add_double (l1, h1, l2, h2, &lv, &hv);
111
112 return immed_double_const (lv, hv, VOIDmode);
113 }
114
115 case MEM:
116 /* If this is a reference to the constant pool, try replacing it with
117 a reference to a new constant. If the resulting address isn't
118 valid, don't return it because we have no way to validize it. */
119 if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF
120 && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)))
121 {
122 tem
123 = force_const_mem (GET_MODE (x),
124 plus_constant (get_pool_constant (XEXP (x, 0)),
125 c));
126 if (memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
127 return tem;
128 }
129 break;
130
131 case CONST:
132 /* If adding to something entirely constant, set a flag
133 so that we can add a CONST around the result. */
134 x = XEXP (x, 0);
135 all_constant = 1;
136 goto restart;
137
138 case SYMBOL_REF:
139 case LABEL_REF:
140 all_constant = 1;
141 break;
142
143 case PLUS:
144 /* The interesting case is adding the integer to a sum.
145 Look for constant term in the sum and combine
146 with C. For an integer constant term, we make a combined
147 integer. For a constant term that is not an explicit integer,
d9b3eb63 148 we cannot really combine, but group them together anyway.
e5671f2b 149
03d937fc
R
150 Restart or use a recursive call in case the remaining operand is
151 something that we handle specially, such as a SYMBOL_REF.
152
153 We may not immediately return from the recursive call here, lest
154 all_constant gets lost. */
e5671f2b
RK
155
156 if (GET_CODE (XEXP (x, 1)) == CONST_INT)
03d937fc
R
157 {
158 c += INTVAL (XEXP (x, 1));
7e4ce834
RH
159
160 if (GET_MODE (x) != VOIDmode)
161 c = trunc_int_for_mode (c, GET_MODE (x));
162
03d937fc
R
163 x = XEXP (x, 0);
164 goto restart;
165 }
b72f00af 166 else if (CONSTANT_P (XEXP (x, 1)))
03d937fc 167 {
b72f00af 168 x = gen_rtx_PLUS (mode, XEXP (x, 0), plus_constant (XEXP (x, 1), c));
03d937fc
R
169 c = 0;
170 }
b72f00af 171 else if (find_constant_term_loc (&y))
03d937fc 172 {
b72f00af
RK
173 /* We need to be careful since X may be shared and we can't
174 modify it in place. */
175 rtx copy = copy_rtx (x);
176 rtx *const_loc = find_constant_term_loc (&copy);
177
178 *const_loc = plus_constant (*const_loc, c);
179 x = copy;
03d937fc
R
180 c = 0;
181 }
38a448ca 182 break;
ed8908e7 183
38a448ca
RH
184 default:
185 break;
18ca7dab
RK
186 }
187
188 if (c != 0)
38a448ca 189 x = gen_rtx_PLUS (mode, x, GEN_INT (c));
18ca7dab
RK
190
191 if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
192 return x;
193 else if (all_constant)
38a448ca 194 return gen_rtx_CONST (mode, x);
18ca7dab
RK
195 else
196 return x;
197}
18ca7dab
RK
198\f
199/* If X is a sum, return a new sum like X but lacking any constant terms.
200 Add all the removed constant terms into *CONSTPTR.
201 X itself is not altered. The result != X if and only if
202 it is not isomorphic to X. */
203
204rtx
502b8322 205eliminate_constant_term (rtx x, rtx *constptr)
18ca7dab 206{
b3694847 207 rtx x0, x1;
18ca7dab
RK
208 rtx tem;
209
210 if (GET_CODE (x) != PLUS)
211 return x;
212
213 /* First handle constants appearing at this level explicitly. */
214 if (GET_CODE (XEXP (x, 1)) == CONST_INT
215 && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr,
216 XEXP (x, 1)))
217 && GET_CODE (tem) == CONST_INT)
218 {
219 *constptr = tem;
220 return eliminate_constant_term (XEXP (x, 0), constptr);
221 }
222
223 tem = const0_rtx;
224 x0 = eliminate_constant_term (XEXP (x, 0), &tem);
225 x1 = eliminate_constant_term (XEXP (x, 1), &tem);
226 if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0))
227 && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x),
228 *constptr, tem))
229 && GET_CODE (tem) == CONST_INT)
230 {
231 *constptr = tem;
38a448ca 232 return gen_rtx_PLUS (GET_MODE (x), x0, x1);
18ca7dab
RK
233 }
234
235 return x;
236}
237
18ca7dab
RK
238/* Return an rtx for the size in bytes of the value of EXP. */
239
240rtx
502b8322 241expr_size (tree exp)
18ca7dab 242{
d25cee4d
RH
243 tree size;
244
245 if (TREE_CODE (exp) == WITH_SIZE_EXPR)
246 size = TREE_OPERAND (exp, 1);
247 else
26979bc2
JH
248 {
249 size = lang_hooks.expr_size (exp);
250 gcc_assert (size);
251 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, exp);
252 }
99098c66 253
37a08a29 254 return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype), 0);
18ca7dab 255}
de8920be
JM
256
257/* Return a wide integer for the size in bytes of the value of EXP, or -1
258 if the size can vary or is larger than an integer. */
259
260HOST_WIDE_INT
502b8322 261int_expr_size (tree exp)
de8920be 262{
d25cee4d
RH
263 tree size;
264
265 if (TREE_CODE (exp) == WITH_SIZE_EXPR)
266 size = TREE_OPERAND (exp, 1);
267 else
26979bc2
JH
268 {
269 size = lang_hooks.expr_size (exp);
270 gcc_assert (size);
271 }
d25cee4d
RH
272
273 if (size == 0 || !host_integerp (size, 0))
de8920be
JM
274 return -1;
275
d25cee4d 276 return tree_low_cst (size, 0);
de8920be 277}
18ca7dab
RK
278\f
279/* Return a copy of X in which all memory references
280 and all constants that involve symbol refs
281 have been replaced with new temporary registers.
282 Also emit code to load the memory locations and constants
283 into those registers.
284
285 If X contains no such constants or memory references,
286 X itself (not a copy) is returned.
287
288 If a constant is found in the address that is not a legitimate constant
289 in an insn, it is left alone in the hope that it might be valid in the
290 address.
291
292 X may contain no arithmetic except addition, subtraction and multiplication.
293 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
294
295static rtx
502b8322 296break_out_memory_refs (rtx x)
18ca7dab 297{
3c0cb5de 298 if (MEM_P (x)
cabeca29 299 || (CONSTANT_P (x) && CONSTANT_ADDRESS_P (x)
18ca7dab 300 && GET_MODE (x) != VOIDmode))
2cca6e3f 301 x = force_reg (GET_MODE (x), x);
18ca7dab
RK
302 else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
303 || GET_CODE (x) == MULT)
304 {
b3694847
SS
305 rtx op0 = break_out_memory_refs (XEXP (x, 0));
306 rtx op1 = break_out_memory_refs (XEXP (x, 1));
2cca6e3f 307
18ca7dab 308 if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
38a448ca 309 x = gen_rtx_fmt_ee (GET_CODE (x), Pmode, op0, op1);
18ca7dab 310 }
2cca6e3f 311
18ca7dab
RK
312 return x;
313}
314
ea534b63 315/* Given X, a memory address in ptr_mode, convert it to an address
498b529f
RK
316 in Pmode, or vice versa (TO_MODE says which way). We take advantage of
317 the fact that pointers are not allowed to overflow by commuting arithmetic
318 operations over conversions so that address arithmetic insns can be
319 used. */
ea534b63 320
498b529f 321rtx
5ae6cd0d
MM
322convert_memory_address (enum machine_mode to_mode ATTRIBUTE_UNUSED,
323 rtx x)
ea534b63 324{
5ae6cd0d 325#ifndef POINTERS_EXTEND_UNSIGNED
7c137931 326 gcc_assert (GET_MODE (x) == to_mode || GET_MODE (x) == VOIDmode);
5ae6cd0d
MM
327 return x;
328#else /* defined(POINTERS_EXTEND_UNSIGNED) */
329 enum machine_mode from_mode;
498b529f 330 rtx temp;
aa0f70e6 331 enum rtx_code code;
498b529f 332
5ae6cd0d
MM
333 /* If X already has the right mode, just return it. */
334 if (GET_MODE (x) == to_mode)
335 return x;
336
337 from_mode = to_mode == ptr_mode ? Pmode : ptr_mode;
338
0b04ec8c
RK
339 /* Here we handle some special cases. If none of them apply, fall through
340 to the default case. */
ea534b63
RK
341 switch (GET_CODE (x))
342 {
343 case CONST_INT:
344 case CONST_DOUBLE:
aa0f70e6
SE
345 if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode))
346 code = TRUNCATE;
347 else if (POINTERS_EXTEND_UNSIGNED < 0)
348 break;
349 else if (POINTERS_EXTEND_UNSIGNED > 0)
350 code = ZERO_EXTEND;
351 else
352 code = SIGN_EXTEND;
353 temp = simplify_unary_operation (code, to_mode, x, from_mode);
354 if (temp)
355 return temp;
356 break;
498b529f 357
d1405722 358 case SUBREG:
5da4f548 359 if ((SUBREG_PROMOTED_VAR_P (x) || REG_POINTER (SUBREG_REG (x)))
6dd12198 360 && GET_MODE (SUBREG_REG (x)) == to_mode)
d1405722
RK
361 return SUBREG_REG (x);
362 break;
363
ea534b63 364 case LABEL_REF:
5da4f548
SE
365 temp = gen_rtx_LABEL_REF (to_mode, XEXP (x, 0));
366 LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x);
367 return temp;
6dd12198 368 break;
498b529f 369
ea534b63 370 case SYMBOL_REF:
ce02ba25
EC
371 temp = shallow_copy_rtx (x);
372 PUT_MODE (temp, to_mode);
5da4f548 373 return temp;
6dd12198 374 break;
ea534b63 375
498b529f 376 case CONST:
5da4f548
SE
377 return gen_rtx_CONST (to_mode,
378 convert_memory_address (to_mode, XEXP (x, 0)));
6dd12198 379 break;
ea534b63 380
0b04ec8c
RK
381 case PLUS:
382 case MULT:
aa0f70e6
SE
383 /* For addition we can safely permute the conversion and addition
384 operation if one operand is a constant and converting the constant
385 does not change it. We can always safely permute them if we are
386 making the address narrower. */
387 if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)
388 || (GET_CODE (x) == PLUS
389 && GET_CODE (XEXP (x, 1)) == CONST_INT
390 && XEXP (x, 1) == convert_memory_address (to_mode, XEXP (x, 1))))
d9b3eb63 391 return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
38a448ca 392 convert_memory_address (to_mode, XEXP (x, 0)),
aa0f70e6 393 XEXP (x, 1));
38a448ca 394 break;
d9b3eb63 395
38a448ca
RH
396 default:
397 break;
ea534b63 398 }
0b04ec8c
RK
399
400 return convert_modes (to_mode, from_mode,
401 x, POINTERS_EXTEND_UNSIGNED);
5ae6cd0d 402#endif /* defined(POINTERS_EXTEND_UNSIGNED) */
ea534b63 403}
18ca7dab
RK
404\f
405/* Return something equivalent to X but valid as a memory address
406 for something of mode MODE. When X is not itself valid, this
407 works by copying X or subexpressions of it into registers. */
408
409rtx
502b8322 410memory_address (enum machine_mode mode, rtx x)
18ca7dab 411{
b3694847 412 rtx oldx = x;
18ca7dab 413
5ae6cd0d 414 x = convert_memory_address (Pmode, x);
ea534b63 415
ba228239 416 /* By passing constant addresses through registers
18ca7dab 417 we get a chance to cse them. */
cabeca29 418 if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x))
18b9ca6f 419 x = force_reg (Pmode, x);
18ca7dab 420
18ca7dab
RK
421 /* We get better cse by rejecting indirect addressing at this stage.
422 Let the combiner create indirect addresses where appropriate.
423 For now, generate the code so that the subexpressions useful to share
424 are visible. But not if cse won't be done! */
18b9ca6f 425 else
18ca7dab 426 {
f8cfc6aa 427 if (! cse_not_expected && !REG_P (x))
18b9ca6f
RK
428 x = break_out_memory_refs (x);
429
430 /* At this point, any valid address is accepted. */
9b305d55
ZW
431 if (memory_address_p (mode, x))
432 goto win;
18b9ca6f
RK
433
434 /* If it was valid before but breaking out memory refs invalidated it,
435 use it the old way. */
436 if (memory_address_p (mode, oldx))
437 goto win2;
438
439 /* Perform machine-dependent transformations on X
440 in certain cases. This is not necessary since the code
441 below can handle all possible cases, but machine-dependent
442 transformations can make better code. */
443 LEGITIMIZE_ADDRESS (x, oldx, mode, win);
444
445 /* PLUS and MULT can appear in special ways
446 as the result of attempts to make an address usable for indexing.
447 Usually they are dealt with by calling force_operand, below.
448 But a sum containing constant terms is special
449 if removing them makes the sum a valid address:
450 then we generate that address in a register
451 and index off of it. We do this because it often makes
452 shorter code, and because the addresses thus generated
453 in registers often become common subexpressions. */
454 if (GET_CODE (x) == PLUS)
455 {
456 rtx constant_term = const0_rtx;
457 rtx y = eliminate_constant_term (x, &constant_term);
458 if (constant_term == const0_rtx
459 || ! memory_address_p (mode, y))
460 x = force_operand (x, NULL_RTX);
461 else
462 {
38a448ca 463 y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term);
18b9ca6f
RK
464 if (! memory_address_p (mode, y))
465 x = force_operand (x, NULL_RTX);
466 else
467 x = y;
468 }
469 }
18ca7dab 470
e475ed2a 471 else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS)
18b9ca6f 472 x = force_operand (x, NULL_RTX);
18ca7dab 473
18b9ca6f
RK
474 /* If we have a register that's an invalid address,
475 it must be a hard reg of the wrong class. Copy it to a pseudo. */
f8cfc6aa 476 else if (REG_P (x))
18b9ca6f
RK
477 x = copy_to_reg (x);
478
479 /* Last resort: copy the value to a register, since
480 the register is a valid address. */
481 else
482 x = force_reg (Pmode, x);
483
484 goto done;
18ca7dab 485
c02a7fbb
RK
486 win2:
487 x = oldx;
488 win:
6d90db3a 489 if (flag_force_addr && ! cse_not_expected && !REG_P (x))
c02a7fbb 490 {
6d90db3a
RH
491 x = force_operand (x, NULL_RTX);
492 x = force_reg (Pmode, x);
c02a7fbb 493 }
18ca7dab 494 }
18b9ca6f
RK
495
496 done:
497
2cca6e3f
RK
498 /* If we didn't change the address, we are done. Otherwise, mark
499 a reg as a pointer if we have REG or REG + CONST_INT. */
500 if (oldx == x)
501 return x;
f8cfc6aa 502 else if (REG_P (x))
bdb429a5 503 mark_reg_pointer (x, BITS_PER_UNIT);
2cca6e3f 504 else if (GET_CODE (x) == PLUS
f8cfc6aa 505 && REG_P (XEXP (x, 0))
2cca6e3f 506 && GET_CODE (XEXP (x, 1)) == CONST_INT)
bdb429a5 507 mark_reg_pointer (XEXP (x, 0), BITS_PER_UNIT);
2cca6e3f 508
18b9ca6f
RK
509 /* OLDX may have been the address on a temporary. Update the address
510 to indicate that X is now used. */
511 update_temp_slot_address (oldx, x);
512
18ca7dab
RK
513 return x;
514}
515
516/* Like `memory_address' but pretend `flag_force_addr' is 0. */
517
518rtx
502b8322 519memory_address_noforce (enum machine_mode mode, rtx x)
18ca7dab
RK
520{
521 int ambient_force_addr = flag_force_addr;
522 rtx val;
523
524 flag_force_addr = 0;
525 val = memory_address (mode, x);
526 flag_force_addr = ambient_force_addr;
527 return val;
528}
529
530/* Convert a mem ref into one with a valid memory address.
531 Pass through anything else unchanged. */
532
533rtx
502b8322 534validize_mem (rtx ref)
18ca7dab 535{
3c0cb5de 536 if (!MEM_P (ref))
18ca7dab 537 return ref;
aacd3885 538 ref = use_anchored_address (ref);
792760b9
RK
539 if (! (flag_force_addr && CONSTANT_ADDRESS_P (XEXP (ref, 0)))
540 && memory_address_p (GET_MODE (ref), XEXP (ref, 0)))
18ca7dab 541 return ref;
792760b9 542
18ca7dab 543 /* Don't alter REF itself, since that is probably a stack slot. */
792760b9 544 return replace_equiv_address (ref, XEXP (ref, 0));
18ca7dab 545}
aacd3885
RS
546
547/* If X is a memory reference to a member of an object block, try rewriting
548 it to use an anchor instead. Return the new memory reference on success
549 and the old one on failure. */
550
551rtx
552use_anchored_address (rtx x)
553{
554 rtx base;
555 HOST_WIDE_INT offset;
556
557 if (!flag_section_anchors)
558 return x;
559
560 if (!MEM_P (x))
561 return x;
562
563 /* Split the address into a base and offset. */
564 base = XEXP (x, 0);
565 offset = 0;
566 if (GET_CODE (base) == CONST
567 && GET_CODE (XEXP (base, 0)) == PLUS
568 && GET_CODE (XEXP (XEXP (base, 0), 1)) == CONST_INT)
569 {
570 offset += INTVAL (XEXP (XEXP (base, 0), 1));
571 base = XEXP (XEXP (base, 0), 0);
572 }
573
574 /* Check whether BASE is suitable for anchors. */
575 if (GET_CODE (base) != SYMBOL_REF
3fa9c136 576 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base)
aacd3885 577 || SYMBOL_REF_ANCHOR_P (base)
434aeebb 578 || SYMBOL_REF_BLOCK (base) == NULL
aacd3885
RS
579 || !targetm.use_anchors_for_symbol_p (base))
580 return x;
581
582 /* Decide where BASE is going to be. */
583 place_block_symbol (base);
584
585 /* Get the anchor we need to use. */
586 offset += SYMBOL_REF_BLOCK_OFFSET (base);
587 base = get_section_anchor (SYMBOL_REF_BLOCK (base), offset,
588 SYMBOL_REF_TLS_MODEL (base));
589
590 /* Work out the offset from the anchor. */
591 offset -= SYMBOL_REF_BLOCK_OFFSET (base);
592
593 /* If we're going to run a CSE pass, force the anchor into a register.
594 We will then be able to reuse registers for several accesses, if the
595 target costs say that that's worthwhile. */
596 if (!cse_not_expected)
597 base = force_reg (GET_MODE (base), base);
598
599 return replace_equiv_address (x, plus_constant (base, offset));
600}
18ca7dab 601\f
18ca7dab
RK
602/* Copy the value or contents of X to a new temp reg and return that reg. */
603
604rtx
502b8322 605copy_to_reg (rtx x)
18ca7dab 606{
b3694847 607 rtx temp = gen_reg_rtx (GET_MODE (x));
d9b3eb63 608
18ca7dab 609 /* If not an operand, must be an address with PLUS and MULT so
d9b3eb63 610 do the computation. */
18ca7dab
RK
611 if (! general_operand (x, VOIDmode))
612 x = force_operand (x, temp);
d9b3eb63 613
18ca7dab
RK
614 if (x != temp)
615 emit_move_insn (temp, x);
616
617 return temp;
618}
619
620/* Like copy_to_reg but always give the new register mode Pmode
621 in case X is a constant. */
622
623rtx
502b8322 624copy_addr_to_reg (rtx x)
18ca7dab
RK
625{
626 return copy_to_mode_reg (Pmode, x);
627}
628
629/* Like copy_to_reg but always give the new register mode MODE
630 in case X is a constant. */
631
632rtx
502b8322 633copy_to_mode_reg (enum machine_mode mode, rtx x)
18ca7dab 634{
b3694847 635 rtx temp = gen_reg_rtx (mode);
d9b3eb63 636
18ca7dab 637 /* If not an operand, must be an address with PLUS and MULT so
d9b3eb63 638 do the computation. */
18ca7dab
RK
639 if (! general_operand (x, VOIDmode))
640 x = force_operand (x, temp);
641
5b0264cb 642 gcc_assert (GET_MODE (x) == mode || GET_MODE (x) == VOIDmode);
18ca7dab
RK
643 if (x != temp)
644 emit_move_insn (temp, x);
645 return temp;
646}
647
648/* Load X into a register if it is not already one.
649 Use mode MODE for the register.
650 X should be valid for mode MODE, but it may be a constant which
651 is valid for all integer modes; that's why caller must specify MODE.
652
653 The caller must not alter the value in the register we return,
654 since we mark it as a "constant" register. */
655
656rtx
502b8322 657force_reg (enum machine_mode mode, rtx x)
18ca7dab 658{
b3694847 659 rtx temp, insn, set;
18ca7dab 660
f8cfc6aa 661 if (REG_P (x))
18ca7dab 662 return x;
d9b3eb63 663
e3c8ea67
RH
664 if (general_operand (x, mode))
665 {
666 temp = gen_reg_rtx (mode);
667 insn = emit_move_insn (temp, x);
668 }
669 else
670 {
671 temp = force_operand (x, NULL_RTX);
f8cfc6aa 672 if (REG_P (temp))
e3c8ea67
RH
673 insn = get_last_insn ();
674 else
675 {
676 rtx temp2 = gen_reg_rtx (mode);
677 insn = emit_move_insn (temp2, temp);
678 temp = temp2;
679 }
680 }
62874575 681
18ca7dab 682 /* Let optimizers know that TEMP's value never changes
62874575
RK
683 and that X can be substituted for it. Don't get confused
684 if INSN set something else (such as a SUBREG of TEMP). */
685 if (CONSTANT_P (x)
686 && (set = single_set (insn)) != 0
fd7acc30
RS
687 && SET_DEST (set) == temp
688 && ! rtx_equal_p (x, SET_SRC (set)))
3d238248 689 set_unique_reg_note (insn, REG_EQUAL, x);
e3c8ea67 690
4a4f95d9
RH
691 /* Let optimizers know that TEMP is a pointer, and if so, the
692 known alignment of that pointer. */
693 {
694 unsigned align = 0;
695 if (GET_CODE (x) == SYMBOL_REF)
696 {
697 align = BITS_PER_UNIT;
698 if (SYMBOL_REF_DECL (x) && DECL_P (SYMBOL_REF_DECL (x)))
699 align = DECL_ALIGN (SYMBOL_REF_DECL (x));
700 }
701 else if (GET_CODE (x) == LABEL_REF)
702 align = BITS_PER_UNIT;
703 else if (GET_CODE (x) == CONST
704 && GET_CODE (XEXP (x, 0)) == PLUS
705 && GET_CODE (XEXP (XEXP (x, 0), 0)) == SYMBOL_REF
706 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
707 {
708 rtx s = XEXP (XEXP (x, 0), 0);
709 rtx c = XEXP (XEXP (x, 0), 1);
710 unsigned sa, ca;
711
712 sa = BITS_PER_UNIT;
713 if (SYMBOL_REF_DECL (s) && DECL_P (SYMBOL_REF_DECL (s)))
714 sa = DECL_ALIGN (SYMBOL_REF_DECL (s));
715
716 ca = exact_log2 (INTVAL (c) & -INTVAL (c)) * BITS_PER_UNIT;
717
718 align = MIN (sa, ca);
719 }
2319ffbb
PB
720 else if (MEM_P (x) && MEM_POINTER (x))
721 align = MEM_ALIGN (x);
4a4f95d9
RH
722
723 if (align)
724 mark_reg_pointer (temp, align);
725 }
726
18ca7dab
RK
727 return temp;
728}
729
730/* If X is a memory ref, copy its contents to a new temp reg and return
731 that reg. Otherwise, return X. */
732
733rtx
502b8322 734force_not_mem (rtx x)
18ca7dab 735{
b3694847 736 rtx temp;
fe3439b0 737
3c0cb5de 738 if (!MEM_P (x) || GET_MODE (x) == BLKmode)
18ca7dab 739 return x;
fe3439b0 740
18ca7dab 741 temp = gen_reg_rtx (GET_MODE (x));
f8ad8d7c
ZD
742
743 if (MEM_POINTER (x))
744 REG_POINTER (temp) = 1;
745
18ca7dab
RK
746 emit_move_insn (temp, x);
747 return temp;
748}
749
750/* Copy X to TARGET (if it's nonzero and a reg)
751 or to a new temp reg and return that reg.
752 MODE is the mode to use for X in case it is a constant. */
753
754rtx
502b8322 755copy_to_suggested_reg (rtx x, rtx target, enum machine_mode mode)
18ca7dab 756{
b3694847 757 rtx temp;
18ca7dab 758
f8cfc6aa 759 if (target && REG_P (target))
18ca7dab
RK
760 temp = target;
761 else
762 temp = gen_reg_rtx (mode);
763
764 emit_move_insn (temp, x);
765 return temp;
766}
767\f
9ff65789
RK
768/* Return the mode to use to store a scalar of TYPE and MODE.
769 PUNSIGNEDP points to the signedness of the type and may be adjusted
770 to show what signedness to use on extension operations.
771
cc2902df 772 FOR_CALL is nonzero if this call is promoting args for a call. */
9ff65789 773
d4453b7a 774#if defined(PROMOTE_MODE) && !defined(PROMOTE_FUNCTION_MODE)
f07e9f0f 775#define PROMOTE_FUNCTION_MODE PROMOTE_MODE
d4453b7a
PB
776#endif
777
9ff65789 778enum machine_mode
502b8322
AJ
779promote_mode (tree type, enum machine_mode mode, int *punsignedp,
780 int for_call ATTRIBUTE_UNUSED)
9ff65789
RK
781{
782 enum tree_code code = TREE_CODE (type);
783 int unsignedp = *punsignedp;
784
d4453b7a 785#ifndef PROMOTE_MODE
9ff65789
RK
786 if (! for_call)
787 return mode;
788#endif
789
790 switch (code)
791 {
d4453b7a 792#ifdef PROMOTE_FUNCTION_MODE
9ff65789 793 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
71d59383 794 case REAL_TYPE: case OFFSET_TYPE:
d4453b7a
PB
795#ifdef PROMOTE_MODE
796 if (for_call)
797 {
798#endif
799 PROMOTE_FUNCTION_MODE (mode, unsignedp, type);
800#ifdef PROMOTE_MODE
801 }
802 else
803 {
804 PROMOTE_MODE (mode, unsignedp, type);
805 }
806#endif
9ff65789
RK
807 break;
808#endif
809
ea534b63 810#ifdef POINTERS_EXTEND_UNSIGNED
56a4c9e2 811 case REFERENCE_TYPE:
9ff65789 812 case POINTER_TYPE:
ea534b63
RK
813 mode = Pmode;
814 unsignedp = POINTERS_EXTEND_UNSIGNED;
9ff65789 815 break;
ea534b63 816#endif
d9b3eb63 817
38a448ca
RH
818 default:
819 break;
9ff65789
RK
820 }
821
822 *punsignedp = unsignedp;
823 return mode;
824}
825\f
18ca7dab
RK
826/* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
827 This pops when ADJUST is positive. ADJUST need not be constant. */
828
829void
502b8322 830adjust_stack (rtx adjust)
18ca7dab
RK
831{
832 rtx temp;
18ca7dab
RK
833
834 if (adjust == const0_rtx)
835 return;
836
1503a7ec
JH
837 /* We expect all variable sized adjustments to be multiple of
838 PREFERRED_STACK_BOUNDARY. */
839 if (GET_CODE (adjust) == CONST_INT)
840 stack_pointer_delta -= INTVAL (adjust);
841
18ca7dab
RK
842 temp = expand_binop (Pmode,
843#ifdef STACK_GROWS_DOWNWARD
844 add_optab,
845#else
846 sub_optab,
847#endif
848 stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
849 OPTAB_LIB_WIDEN);
850
851 if (temp != stack_pointer_rtx)
852 emit_move_insn (stack_pointer_rtx, temp);
853}
854
855/* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
856 This pushes when ADJUST is positive. ADJUST need not be constant. */
857
858void
502b8322 859anti_adjust_stack (rtx adjust)
18ca7dab
RK
860{
861 rtx temp;
18ca7dab
RK
862
863 if (adjust == const0_rtx)
864 return;
865
1503a7ec
JH
866 /* We expect all variable sized adjustments to be multiple of
867 PREFERRED_STACK_BOUNDARY. */
868 if (GET_CODE (adjust) == CONST_INT)
869 stack_pointer_delta += INTVAL (adjust);
870
18ca7dab
RK
871 temp = expand_binop (Pmode,
872#ifdef STACK_GROWS_DOWNWARD
873 sub_optab,
874#else
875 add_optab,
876#endif
877 stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
878 OPTAB_LIB_WIDEN);
879
880 if (temp != stack_pointer_rtx)
881 emit_move_insn (stack_pointer_rtx, temp);
882}
883
884/* Round the size of a block to be pushed up to the boundary required
885 by this machine. SIZE is the desired size, which need not be constant. */
886
4dd9b044 887static rtx
502b8322 888round_push (rtx size)
18ca7dab 889{
c795bca9 890 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
41ee3204 891
18ca7dab
RK
892 if (align == 1)
893 return size;
41ee3204 894
18ca7dab
RK
895 if (GET_CODE (size) == CONST_INT)
896 {
41ee3204
OH
897 HOST_WIDE_INT new = (INTVAL (size) + align - 1) / align * align;
898
18ca7dab 899 if (INTVAL (size) != new)
b1ec3c92 900 size = GEN_INT (new);
18ca7dab
RK
901 }
902 else
903 {
5244db05 904 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
0f41302f
MS
905 but we know it can't. So add ourselves and then do
906 TRUNC_DIV_EXPR. */
5244db05
RK
907 size = expand_binop (Pmode, add_optab, size, GEN_INT (align - 1),
908 NULL_RTX, 1, OPTAB_LIB_WIDEN);
909 size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, GEN_INT (align),
b1ec3c92
CH
910 NULL_RTX, 1);
911 size = expand_mult (Pmode, size, GEN_INT (align), NULL_RTX, 1);
18ca7dab 912 }
41ee3204 913
18ca7dab
RK
914 return size;
915}
916\f
59257ff7
RK
917/* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
918 to a previously-created save area. If no save area has been allocated,
919 this function will allocate one. If a save area is specified, it
920 must be of the proper mode.
921
922 The insns are emitted after insn AFTER, if nonzero, otherwise the insns
923 are emitted at the current position. */
924
925void
502b8322 926emit_stack_save (enum save_level save_level, rtx *psave, rtx after)
59257ff7
RK
927{
928 rtx sa = *psave;
929 /* The default is that we use a move insn and save in a Pmode object. */
502b8322 930 rtx (*fcn) (rtx, rtx) = gen_move_insn;
a260abc9 931 enum machine_mode mode = STACK_SAVEAREA_MODE (save_level);
59257ff7
RK
932
933 /* See if this machine has anything special to do for this kind of save. */
934 switch (save_level)
935 {
936#ifdef HAVE_save_stack_block
937 case SAVE_BLOCK:
938 if (HAVE_save_stack_block)
a260abc9 939 fcn = gen_save_stack_block;
59257ff7
RK
940 break;
941#endif
942#ifdef HAVE_save_stack_function
943 case SAVE_FUNCTION:
944 if (HAVE_save_stack_function)
a260abc9 945 fcn = gen_save_stack_function;
59257ff7
RK
946 break;
947#endif
948#ifdef HAVE_save_stack_nonlocal
949 case SAVE_NONLOCAL:
950 if (HAVE_save_stack_nonlocal)
a260abc9 951 fcn = gen_save_stack_nonlocal;
59257ff7
RK
952 break;
953#endif
38a448ca
RH
954 default:
955 break;
59257ff7
RK
956 }
957
958 /* If there is no save area and we have to allocate one, do so. Otherwise
959 verify the save area is the proper mode. */
960
961 if (sa == 0)
962 {
963 if (mode != VOIDmode)
964 {
965 if (save_level == SAVE_NONLOCAL)
966 *psave = sa = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
967 else
968 *psave = sa = gen_reg_rtx (mode);
969 }
970 }
59257ff7
RK
971
972 if (after)
700f6f98
RK
973 {
974 rtx seq;
975
976 start_sequence ();
a494ed43 977 do_pending_stack_adjust ();
5460015d
JW
978 /* We must validize inside the sequence, to ensure that any instructions
979 created by the validize call also get moved to the right place. */
980 if (sa != 0)
981 sa = validize_mem (sa);
d072107f 982 emit_insn (fcn (sa, stack_pointer_rtx));
2f937369 983 seq = get_insns ();
700f6f98
RK
984 end_sequence ();
985 emit_insn_after (seq, after);
986 }
59257ff7 987 else
5460015d 988 {
a494ed43 989 do_pending_stack_adjust ();
5460015d
JW
990 if (sa != 0)
991 sa = validize_mem (sa);
992 emit_insn (fcn (sa, stack_pointer_rtx));
993 }
59257ff7
RK
994}
995
996/* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
d9b3eb63 997 area made by emit_stack_save. If it is zero, we have nothing to do.
59257ff7 998
d9b3eb63 999 Put any emitted insns after insn AFTER, if nonzero, otherwise at
59257ff7
RK
1000 current position. */
1001
1002void
502b8322 1003emit_stack_restore (enum save_level save_level, rtx sa, rtx after)
59257ff7
RK
1004{
1005 /* The default is that we use a move insn. */
502b8322 1006 rtx (*fcn) (rtx, rtx) = gen_move_insn;
59257ff7
RK
1007
1008 /* See if this machine has anything special to do for this kind of save. */
1009 switch (save_level)
1010 {
1011#ifdef HAVE_restore_stack_block
1012 case SAVE_BLOCK:
1013 if (HAVE_restore_stack_block)
1014 fcn = gen_restore_stack_block;
1015 break;
1016#endif
1017#ifdef HAVE_restore_stack_function
1018 case SAVE_FUNCTION:
1019 if (HAVE_restore_stack_function)
1020 fcn = gen_restore_stack_function;
1021 break;
1022#endif
1023#ifdef HAVE_restore_stack_nonlocal
59257ff7
RK
1024 case SAVE_NONLOCAL:
1025 if (HAVE_restore_stack_nonlocal)
1026 fcn = gen_restore_stack_nonlocal;
1027 break;
1028#endif
38a448ca
RH
1029 default:
1030 break;
59257ff7
RK
1031 }
1032
d072107f 1033 if (sa != 0)
260f91c2
DJ
1034 {
1035 sa = validize_mem (sa);
1036 /* These clobbers prevent the scheduler from moving
1037 references to variable arrays below the code
4b7e68e7 1038 that deletes (pops) the arrays. */
260f91c2 1039 emit_insn (gen_rtx_CLOBBER (VOIDmode,
502b8322 1040 gen_rtx_MEM (BLKmode,
260f91c2
DJ
1041 gen_rtx_SCRATCH (VOIDmode))));
1042 emit_insn (gen_rtx_CLOBBER (VOIDmode,
1043 gen_rtx_MEM (BLKmode, stack_pointer_rtx)));
1044 }
d072107f 1045
a494ed43
EB
1046 discard_pending_stack_adjust ();
1047
59257ff7 1048 if (after)
700f6f98
RK
1049 {
1050 rtx seq;
1051
1052 start_sequence ();
d072107f 1053 emit_insn (fcn (stack_pointer_rtx, sa));
2f937369 1054 seq = get_insns ();
700f6f98
RK
1055 end_sequence ();
1056 emit_insn_after (seq, after);
1057 }
59257ff7 1058 else
d072107f 1059 emit_insn (fcn (stack_pointer_rtx, sa));
59257ff7 1060}
6de9cd9a
DN
1061
1062/* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1063 function. This function should be called whenever we allocate or
1064 deallocate dynamic stack space. */
1065
1066void
1067update_nonlocal_goto_save_area (void)
1068{
1069 tree t_save;
1070 rtx r_save;
1071
1072 /* The nonlocal_goto_save_area object is an array of N pointers. The
1073 first one is used for the frame pointer save; the rest are sized by
1074 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1075 of the stack save area slots. */
3244e67d
RS
1076 t_save = build4 (ARRAY_REF, ptr_type_node, cfun->nonlocal_goto_save_area,
1077 integer_one_node, NULL_TREE, NULL_TREE);
6de9cd9a
DN
1078 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
1079
1080 emit_stack_save (SAVE_NONLOCAL, &r_save, NULL_RTX);
1081}
59257ff7 1082\f
18ca7dab
RK
1083/* Return an rtx representing the address of an area of memory dynamically
1084 pushed on the stack. This region of memory is always aligned to
1085 a multiple of BIGGEST_ALIGNMENT.
1086
1087 Any required stack pointer alignment is preserved.
1088
1089 SIZE is an rtx representing the size of the area.
091ad0b9
RK
1090 TARGET is a place in which the address can be placed.
1091
1092 KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */
18ca7dab
RK
1093
1094rtx
502b8322 1095allocate_dynamic_stack_space (rtx size, rtx target, int known_align)
18ca7dab 1096{
15fc0026 1097 /* If we're asking for zero bytes, it doesn't matter what we point
9faa82d8 1098 to since we can't dereference it. But return a reasonable
15fc0026
RK
1099 address anyway. */
1100 if (size == const0_rtx)
1101 return virtual_stack_dynamic_rtx;
1102
1103 /* Otherwise, show we're calling alloca or equivalent. */
1104 current_function_calls_alloca = 1;
1105
18ca7dab
RK
1106 /* Ensure the size is in the proper mode. */
1107 if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
1108 size = convert_to_mode (Pmode, size, 1);
1109
c2f8b491
JH
1110 /* We can't attempt to minimize alignment necessary, because we don't
1111 know the final value of preferred_stack_boundary yet while executing
1112 this code. */
c2f8b491 1113 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
c2f8b491 1114
18ca7dab
RK
1115 /* We will need to ensure that the address we return is aligned to
1116 BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
d9b3eb63 1117 always know its final value at this point in the compilation (it
18ca7dab
RK
1118 might depend on the size of the outgoing parameter lists, for
1119 example), so we must align the value to be returned in that case.
cc2902df 1120 (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
18ca7dab
RK
1121 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1122 We must also do an alignment operation on the returned value if
1123 the stack pointer alignment is less strict that BIGGEST_ALIGNMENT.
1124
1125 If we have to align, we must leave space in SIZE for the hole
1126 that might result from the alignment operation. */
1127
31cdd499 1128#if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
515a7242
JW
1129#define MUST_ALIGN 1
1130#else
c795bca9 1131#define MUST_ALIGN (PREFERRED_STACK_BOUNDARY < BIGGEST_ALIGNMENT)
18ca7dab
RK
1132#endif
1133
515a7242 1134 if (MUST_ALIGN)
d5457140 1135 size
d9b3eb63 1136 = force_operand (plus_constant (size,
d5457140
RK
1137 BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
1138 NULL_RTX);
1d9d04f8 1139
18ca7dab
RK
1140#ifdef SETJMP_VIA_SAVE_AREA
1141 /* If setjmp restores regs from a save area in the stack frame,
1142 avoid clobbering the reg save area. Note that the offset of
1143 virtual_incoming_args_rtx includes the preallocated stack args space.
1144 It would be no problem to clobber that, but it's on the wrong side
d0828b31
DM
1145 of the old save area.
1146
1147 What used to happen is that, since we did not know for sure
1148 whether setjmp() was invoked until after RTL generation, we
1149 would use reg notes to store the "optimized" size and fix things
1150 up later. These days we know this information before we ever
1151 start building RTL so the reg notes are unnecessary. */
1152 if (!current_function_calls_setjmp)
1153 {
1154 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
c9ec4f99 1155
d0828b31
DM
1156 /* ??? Code below assumes that the save area needs maximal
1157 alignment. This constraint may be too strong. */
1158 gcc_assert (PREFERRED_STACK_BOUNDARY == BIGGEST_ALIGNMENT);
c9ec4f99 1159
d0828b31
DM
1160 if (GET_CODE (size) == CONST_INT)
1161 {
1162 HOST_WIDE_INT new = INTVAL (size) / align * align;
1163
1164 if (INTVAL (size) != new)
1165 size = GEN_INT (new);
1166 }
1167 else
1168 {
1169 /* Since we know overflow is not possible, we avoid using
1170 CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */
1171 size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size,
1172 GEN_INT (align), NULL_RTX, 1);
1173 size = expand_mult (Pmode, size,
1174 GEN_INT (align), NULL_RTX, 1);
1175 }
1176 }
1177 else
1178 {
1179 rtx dynamic_offset
1180 = expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx,
1181 stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN);
1182
1183 size = expand_binop (Pmode, add_optab, size, dynamic_offset,
1184 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1185 }
18ca7dab
RK
1186#endif /* SETJMP_VIA_SAVE_AREA */
1187
1188 /* Round the size to a multiple of the required stack alignment.
1189 Since the stack if presumed to be rounded before this allocation,
1190 this will maintain the required alignment.
1191
1192 If the stack grows downward, we could save an insn by subtracting
1193 SIZE from the stack pointer and then aligning the stack pointer.
1194 The problem with this is that the stack pointer may be unaligned
1195 between the execution of the subtraction and alignment insns and
1196 some machines do not allow this. Even on those that do, some
1197 signal handlers malfunction if a signal should occur between those
1198 insns. Since this is an extremely rare event, we have no reliable
1199 way of knowing which systems have this problem. So we avoid even
1200 momentarily mis-aligning the stack. */
1201
86b25e81
RS
1202 /* If we added a variable amount to SIZE,
1203 we can no longer assume it is aligned. */
515a7242 1204#if !defined (SETJMP_VIA_SAVE_AREA)
c795bca9 1205 if (MUST_ALIGN || known_align % PREFERRED_STACK_BOUNDARY != 0)
34c9156a 1206#endif
091ad0b9 1207 size = round_push (size);
18ca7dab
RK
1208
1209 do_pending_stack_adjust ();
1210
1503a7ec 1211 /* We ought to be called always on the toplevel and stack ought to be aligned
a1f300c0 1212 properly. */
5b0264cb
NS
1213 gcc_assert (!(stack_pointer_delta
1214 % (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)));
1503a7ec 1215
edff2491
RK
1216 /* If needed, check that we have the required amount of stack. Take into
1217 account what has already been checked. */
1218 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
1219 probe_stack_range (STACK_CHECK_MAX_FRAME_SIZE + STACK_CHECK_PROTECT, size);
1220
d5457140 1221 /* Don't use a TARGET that isn't a pseudo or is the wrong mode. */
f8cfc6aa 1222 if (target == 0 || !REG_P (target)
d5457140
RK
1223 || REGNO (target) < FIRST_PSEUDO_REGISTER
1224 || GET_MODE (target) != Pmode)
18ca7dab
RK
1225 target = gen_reg_rtx (Pmode);
1226
bdb429a5 1227 mark_reg_pointer (target, known_align);
3ad69266 1228
18ca7dab
RK
1229 /* Perform the required allocation from the stack. Some systems do
1230 this differently than simply incrementing/decrementing from the
38a448ca 1231 stack pointer, such as acquiring the space by calling malloc(). */
18ca7dab
RK
1232#ifdef HAVE_allocate_stack
1233 if (HAVE_allocate_stack)
1234 {
39403d82 1235 enum machine_mode mode = STACK_SIZE_MODE;
a995e389 1236 insn_operand_predicate_fn pred;
39403d82 1237
4b6c1672
RK
1238 /* We don't have to check against the predicate for operand 0 since
1239 TARGET is known to be a pseudo of the proper mode, which must
1240 be valid for the operand. For operand 1, convert to the
1241 proper mode and validate. */
c5c76735 1242 if (mode == VOIDmode)
4b6c1672 1243 mode = insn_data[(int) CODE_FOR_allocate_stack].operand[1].mode;
c5c76735 1244
a995e389
RH
1245 pred = insn_data[(int) CODE_FOR_allocate_stack].operand[1].predicate;
1246 if (pred && ! ((*pred) (size, mode)))
05d482b9 1247 size = copy_to_mode_reg (mode, convert_to_mode (mode, size, 1));
18ca7dab 1248
38a448ca 1249 emit_insn (gen_allocate_stack (target, size));
18ca7dab
RK
1250 }
1251 else
1252#endif
ea534b63 1253 {
38a448ca
RH
1254#ifndef STACK_GROWS_DOWNWARD
1255 emit_move_insn (target, virtual_stack_dynamic_rtx);
1256#endif
a157febd
GK
1257
1258 /* Check stack bounds if necessary. */
1259 if (current_function_limit_stack)
1260 {
1261 rtx available;
1262 rtx space_available = gen_label_rtx ();
1263#ifdef STACK_GROWS_DOWNWARD
d9b3eb63 1264 available = expand_binop (Pmode, sub_optab,
a157febd
GK
1265 stack_pointer_rtx, stack_limit_rtx,
1266 NULL_RTX, 1, OPTAB_WIDEN);
1267#else
d9b3eb63 1268 available = expand_binop (Pmode, sub_optab,
a157febd
GK
1269 stack_limit_rtx, stack_pointer_rtx,
1270 NULL_RTX, 1, OPTAB_WIDEN);
1271#endif
1272 emit_cmp_and_jump_insns (available, size, GEU, NULL_RTX, Pmode, 1,
a06ef755 1273 space_available);
a157febd
GK
1274#ifdef HAVE_trap
1275 if (HAVE_trap)
1276 emit_insn (gen_trap ());
1277 else
1278#endif
1279 error ("stack limits not supported on this target");
1280 emit_barrier ();
1281 emit_label (space_available);
1282 }
1283
ea534b63 1284 anti_adjust_stack (size);
d5457140 1285
18ca7dab 1286#ifdef STACK_GROWS_DOWNWARD
ca56cd30 1287 emit_move_insn (target, virtual_stack_dynamic_rtx);
18ca7dab 1288#endif
38a448ca 1289 }
18ca7dab 1290
515a7242 1291 if (MUST_ALIGN)
091ad0b9 1292 {
5244db05 1293 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
0f41302f
MS
1294 but we know it can't. So add ourselves and then do
1295 TRUNC_DIV_EXPR. */
0f56a403 1296 target = expand_binop (Pmode, add_optab, target,
5244db05
RK
1297 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
1298 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1299 target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target,
b1ec3c92
CH
1300 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
1301 NULL_RTX, 1);
091ad0b9 1302 target = expand_mult (Pmode, target,
b1ec3c92
CH
1303 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
1304 NULL_RTX, 1);
091ad0b9 1305 }
d9b3eb63 1306
15fc0026 1307 /* Record the new stack level for nonlocal gotos. */
6de9cd9a
DN
1308 if (cfun->nonlocal_goto_save_area != 0)
1309 update_nonlocal_goto_save_area ();
15fc0026 1310
18ca7dab
RK
1311 return target;
1312}
1313\f
d9b3eb63 1314/* A front end may want to override GCC's stack checking by providing a
14a774a9
RK
1315 run-time routine to call to check the stack, so provide a mechanism for
1316 calling that routine. */
1317
e2500fed 1318static GTY(()) rtx stack_check_libfunc;
14a774a9
RK
1319
1320void
502b8322 1321set_stack_check_libfunc (rtx libfunc)
14a774a9
RK
1322{
1323 stack_check_libfunc = libfunc;
1324}
1325\f
edff2491
RK
1326/* Emit one stack probe at ADDRESS, an address within the stack. */
1327
1328static void
502b8322 1329emit_stack_probe (rtx address)
edff2491 1330{
38a448ca 1331 rtx memref = gen_rtx_MEM (word_mode, address);
edff2491
RK
1332
1333 MEM_VOLATILE_P (memref) = 1;
1334
1335 if (STACK_CHECK_PROBE_LOAD)
1336 emit_move_insn (gen_reg_rtx (word_mode), memref);
1337 else
1338 emit_move_insn (memref, const0_rtx);
1339}
1340
d9b3eb63 1341/* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
edff2491
RK
1342 FIRST is a constant and size is a Pmode RTX. These are offsets from the
1343 current stack pointer. STACK_GROWS_DOWNWARD says whether to add or
1344 subtract from the stack. If SIZE is constant, this is done
1345 with a fixed number of probes. Otherwise, we must make a loop. */
1346
1347#ifdef STACK_GROWS_DOWNWARD
1348#define STACK_GROW_OP MINUS
1349#else
1350#define STACK_GROW_OP PLUS
1351#endif
1352
1353void
502b8322 1354probe_stack_range (HOST_WIDE_INT first, rtx size)
edff2491 1355{
4b6c1672
RK
1356 /* First ensure SIZE is Pmode. */
1357 if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
1358 size = convert_to_mode (Pmode, size, 1);
1359
1360 /* Next see if the front end has set up a function for us to call to
14a774a9
RK
1361 check the stack. */
1362 if (stack_check_libfunc != 0)
f5f5363f
RK
1363 {
1364 rtx addr = memory_address (QImode,
2b3aadfc
RH
1365 gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1366 stack_pointer_rtx,
1367 plus_constant (size, first)));
f5f5363f 1368
5ae6cd0d 1369 addr = convert_memory_address (ptr_mode, addr);
1258ee80 1370 emit_library_call (stack_check_libfunc, LCT_NORMAL, VOIDmode, 1, addr,
f5f5363f
RK
1371 ptr_mode);
1372 }
14a774a9
RK
1373
1374 /* Next see if we have an insn to check the stack. Use it if so. */
edff2491 1375#ifdef HAVE_check_stack
14a774a9 1376 else if (HAVE_check_stack)
edff2491 1377 {
a995e389 1378 insn_operand_predicate_fn pred;
38a448ca 1379 rtx last_addr
2b3aadfc
RH
1380 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1381 stack_pointer_rtx,
1382 plus_constant (size, first)),
38a448ca 1383 NULL_RTX);
edff2491 1384
a995e389
RH
1385 pred = insn_data[(int) CODE_FOR_check_stack].operand[0].predicate;
1386 if (pred && ! ((*pred) (last_addr, Pmode)))
c5c76735 1387 last_addr = copy_to_mode_reg (Pmode, last_addr);
edff2491 1388
c5c76735 1389 emit_insn (gen_check_stack (last_addr));
edff2491
RK
1390 }
1391#endif
1392
1393 /* If we have to generate explicit probes, see if we have a constant
95a086b1 1394 small number of them to generate. If so, that's the easy case. */
14a774a9
RK
1395 else if (GET_CODE (size) == CONST_INT
1396 && INTVAL (size) < 10 * STACK_CHECK_PROBE_INTERVAL)
edff2491
RK
1397 {
1398 HOST_WIDE_INT offset;
1399
1400 /* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL
1401 for values of N from 1 until it exceeds LAST. If only one
1402 probe is needed, this will not generate any code. Then probe
1403 at LAST. */
1404 for (offset = first + STACK_CHECK_PROBE_INTERVAL;
1405 offset < INTVAL (size);
1406 offset = offset + STACK_CHECK_PROBE_INTERVAL)
38a448ca
RH
1407 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1408 stack_pointer_rtx,
1409 GEN_INT (offset)));
edff2491 1410
38a448ca
RH
1411 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1412 stack_pointer_rtx,
1413 plus_constant (size, first)));
edff2491
RK
1414 }
1415
1416 /* In the variable case, do the same as above, but in a loop. We emit loop
1417 notes so that loop optimization can be done. */
1418 else
1419 {
1420 rtx test_addr
38a448ca
RH
1421 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1422 stack_pointer_rtx,
1423 GEN_INT (first + STACK_CHECK_PROBE_INTERVAL)),
edff2491
RK
1424 NULL_RTX);
1425 rtx last_addr
38a448ca
RH
1426 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1427 stack_pointer_rtx,
1428 plus_constant (size, first)),
edff2491
RK
1429 NULL_RTX);
1430 rtx incr = GEN_INT (STACK_CHECK_PROBE_INTERVAL);
1431 rtx loop_lab = gen_label_rtx ();
1432 rtx test_lab = gen_label_rtx ();
1433 rtx end_lab = gen_label_rtx ();
1434 rtx temp;
1435
f8cfc6aa 1436 if (!REG_P (test_addr)
edff2491
RK
1437 || REGNO (test_addr) < FIRST_PSEUDO_REGISTER)
1438 test_addr = force_reg (Pmode, test_addr);
1439
edff2491
RK
1440 emit_jump (test_lab);
1441
1442 emit_label (loop_lab);
1443 emit_stack_probe (test_addr);
1444
edff2491
RK
1445#ifdef STACK_GROWS_DOWNWARD
1446#define CMP_OPCODE GTU
1447 temp = expand_binop (Pmode, sub_optab, test_addr, incr, test_addr,
1448 1, OPTAB_WIDEN);
1449#else
1450#define CMP_OPCODE LTU
1451 temp = expand_binop (Pmode, add_optab, test_addr, incr, test_addr,
1452 1, OPTAB_WIDEN);
1453#endif
1454
5b0264cb 1455 gcc_assert (temp == test_addr);
edff2491
RK
1456
1457 emit_label (test_lab);
c5d5d461 1458 emit_cmp_and_jump_insns (test_addr, last_addr, CMP_OPCODE,
a06ef755 1459 NULL_RTX, Pmode, 1, loop_lab);
edff2491 1460 emit_jump (end_lab);
edff2491
RK
1461 emit_label (end_lab);
1462
1463 emit_stack_probe (last_addr);
1464 }
1465}
1466\f
18ca7dab
RK
1467/* Return an rtx representing the register or memory location
1468 in which a scalar value of data type VALTYPE
1469 was returned by a function call to function FUNC.
1d636cc6
RG
1470 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1471 function is known, otherwise 0.
4dc07bd7
JJ
1472 OUTGOING is 1 if on a machine with register windows this function
1473 should return the register in which the function will put its result
30f7a378 1474 and 0 otherwise. */
18ca7dab
RK
1475
1476rtx
1d636cc6 1477hard_function_value (tree valtype, tree func, tree fntype,
502b8322 1478 int outgoing ATTRIBUTE_UNUSED)
18ca7dab 1479{
4dc07bd7 1480 rtx val;
770ae6cc 1481
1d636cc6 1482 val = targetm.calls.function_value (valtype, func ? func : fntype, outgoing);
770ae6cc 1483
f8cfc6aa 1484 if (REG_P (val)
e1a4071f
JL
1485 && GET_MODE (val) == BLKmode)
1486 {
770ae6cc 1487 unsigned HOST_WIDE_INT bytes = int_size_in_bytes (valtype);
e1a4071f 1488 enum machine_mode tmpmode;
770ae6cc 1489
d9b3eb63 1490 /* int_size_in_bytes can return -1. We don't need a check here
535a42b1
NS
1491 since the value of bytes will then be large enough that no
1492 mode will match anyway. */
d9b3eb63 1493
e1a4071f 1494 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
0fb7aeda
KH
1495 tmpmode != VOIDmode;
1496 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
1497 {
1498 /* Have we found a large enough mode? */
1499 if (GET_MODE_SIZE (tmpmode) >= bytes)
1500 break;
1501 }
e1a4071f
JL
1502
1503 /* No suitable mode found. */
5b0264cb 1504 gcc_assert (tmpmode != VOIDmode);
e1a4071f
JL
1505
1506 PUT_MODE (val, tmpmode);
d9b3eb63 1507 }
e1a4071f 1508 return val;
18ca7dab
RK
1509}
1510
1511/* Return an rtx representing the register or memory location
1512 in which a scalar value of mode MODE was returned by a library call. */
1513
1514rtx
502b8322 1515hard_libcall_value (enum machine_mode mode)
18ca7dab
RK
1516{
1517 return LIBCALL_VALUE (mode);
1518}
0c5e217d
RS
1519
1520/* Look up the tree code for a given rtx code
1521 to provide the arithmetic operation for REAL_ARITHMETIC.
1522 The function returns an int because the caller may not know
1523 what `enum tree_code' means. */
1524
1525int
502b8322 1526rtx_to_tree_code (enum rtx_code code)
0c5e217d
RS
1527{
1528 enum tree_code tcode;
1529
1530 switch (code)
1531 {
1532 case PLUS:
1533 tcode = PLUS_EXPR;
1534 break;
1535 case MINUS:
1536 tcode = MINUS_EXPR;
1537 break;
1538 case MULT:
1539 tcode = MULT_EXPR;
1540 break;
1541 case DIV:
1542 tcode = RDIV_EXPR;
1543 break;
1544 case SMIN:
1545 tcode = MIN_EXPR;
1546 break;
1547 case SMAX:
1548 tcode = MAX_EXPR;
1549 break;
1550 default:
1551 tcode = LAST_AND_UNUSED_TREE_CODE;
1552 break;
1553 }
1554 return ((int) tcode);
1555}
e2500fed
GK
1556
1557#include "gt-explow.h"