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c-common.c: Include <stdlib.h> and <string.h>/<strings.h>.
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1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987, 91, 94, 95, 96, 1997 Free Software Foundation, Inc.
3
4 This file is part of GNU CC.
5
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
10
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
20
21
22 #include "config.h"
23 #include <stdio.h>
24 #include "rtl.h"
25 #include "tree.h"
26 #include "flags.h"
27 #include "expr.h"
28 #include "hard-reg-set.h"
29 #include "insn-config.h"
30 #include "recog.h"
31 #include "insn-flags.h"
32 #include "insn-codes.h"
33
34 static rtx break_out_memory_refs PROTO((rtx));
35 static void emit_stack_probe PROTO((rtx));
36 /* Return an rtx for the sum of X and the integer C.
37
38 This function should be used via the `plus_constant' macro. */
39
40 rtx
41 plus_constant_wide (x, c)
42 register rtx x;
43 register HOST_WIDE_INT c;
44 {
45 register RTX_CODE code;
46 register enum machine_mode mode;
47 register rtx tem;
48 int all_constant = 0;
49
50 if (c == 0)
51 return x;
52
53 restart:
54
55 code = GET_CODE (x);
56 mode = GET_MODE (x);
57 switch (code)
58 {
59 case CONST_INT:
60 return GEN_INT (INTVAL (x) + c);
61
62 case CONST_DOUBLE:
63 {
64 HOST_WIDE_INT l1 = CONST_DOUBLE_LOW (x);
65 HOST_WIDE_INT h1 = CONST_DOUBLE_HIGH (x);
66 HOST_WIDE_INT l2 = c;
67 HOST_WIDE_INT h2 = c < 0 ? ~0 : 0;
68 HOST_WIDE_INT lv, hv;
69
70 add_double (l1, h1, l2, h2, &lv, &hv);
71
72 return immed_double_const (lv, hv, VOIDmode);
73 }
74
75 case MEM:
76 /* If this is a reference to the constant pool, try replacing it with
77 a reference to a new constant. If the resulting address isn't
78 valid, don't return it because we have no way to validize it. */
79 if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF
80 && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)))
81 {
82 /* Any rtl we create here must go in a saveable obstack, since
83 we might have been called from within combine. */
84 push_obstacks_nochange ();
85 rtl_in_saveable_obstack ();
86 tem
87 = force_const_mem (GET_MODE (x),
88 plus_constant (get_pool_constant (XEXP (x, 0)),
89 c));
90 pop_obstacks ();
91 if (memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
92 return tem;
93 }
94 break;
95
96 case CONST:
97 /* If adding to something entirely constant, set a flag
98 so that we can add a CONST around the result. */
99 x = XEXP (x, 0);
100 all_constant = 1;
101 goto restart;
102
103 case SYMBOL_REF:
104 case LABEL_REF:
105 all_constant = 1;
106 break;
107
108 case PLUS:
109 /* The interesting case is adding the integer to a sum.
110 Look for constant term in the sum and combine
111 with C. For an integer constant term, we make a combined
112 integer. For a constant term that is not an explicit integer,
113 we cannot really combine, but group them together anyway.
114
115 Use a recursive call in case the remaining operand is something
116 that we handle specially, such as a SYMBOL_REF. */
117
118 if (GET_CODE (XEXP (x, 1)) == CONST_INT)
119 return plus_constant (XEXP (x, 0), c + INTVAL (XEXP (x, 1)));
120 else if (CONSTANT_P (XEXP (x, 0)))
121 return gen_rtx_PLUS (mode,
122 plus_constant (XEXP (x, 0), c),
123 XEXP (x, 1));
124 else if (CONSTANT_P (XEXP (x, 1)))
125 return gen_rtx_PLUS (mode,
126 XEXP (x, 0),
127 plus_constant (XEXP (x, 1), c));
128 break;
129
130 default:
131 break;
132 }
133
134 if (c != 0)
135 x = gen_rtx_PLUS (mode, x, GEN_INT (c));
136
137 if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
138 return x;
139 else if (all_constant)
140 return gen_rtx_CONST (mode, x);
141 else
142 return x;
143 }
144
145 /* This is the same as `plus_constant', except that it handles LO_SUM.
146
147 This function should be used via the `plus_constant_for_output' macro. */
148
149 rtx
150 plus_constant_for_output_wide (x, c)
151 register rtx x;
152 register HOST_WIDE_INT c;
153 {
154 register RTX_CODE code = GET_CODE (x);
155 register enum machine_mode mode = GET_MODE (x);
156
157 if (GET_CODE (x) == LO_SUM)
158 return gen_rtx_LO_SUM (mode, XEXP (x, 0),
159 plus_constant_for_output (XEXP (x, 1), c));
160
161 else
162 return plus_constant (x, c);
163 }
164 \f
165 /* If X is a sum, return a new sum like X but lacking any constant terms.
166 Add all the removed constant terms into *CONSTPTR.
167 X itself is not altered. The result != X if and only if
168 it is not isomorphic to X. */
169
170 rtx
171 eliminate_constant_term (x, constptr)
172 rtx x;
173 rtx *constptr;
174 {
175 register rtx x0, x1;
176 rtx tem;
177
178 if (GET_CODE (x) != PLUS)
179 return x;
180
181 /* First handle constants appearing at this level explicitly. */
182 if (GET_CODE (XEXP (x, 1)) == CONST_INT
183 && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr,
184 XEXP (x, 1)))
185 && GET_CODE (tem) == CONST_INT)
186 {
187 *constptr = tem;
188 return eliminate_constant_term (XEXP (x, 0), constptr);
189 }
190
191 tem = const0_rtx;
192 x0 = eliminate_constant_term (XEXP (x, 0), &tem);
193 x1 = eliminate_constant_term (XEXP (x, 1), &tem);
194 if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0))
195 && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x),
196 *constptr, tem))
197 && GET_CODE (tem) == CONST_INT)
198 {
199 *constptr = tem;
200 return gen_rtx_PLUS (GET_MODE (x), x0, x1);
201 }
202
203 return x;
204 }
205
206 /* Returns the insn that next references REG after INSN, or 0
207 if REG is clobbered before next referenced or we cannot find
208 an insn that references REG in a straight-line piece of code. */
209
210 rtx
211 find_next_ref (reg, insn)
212 rtx reg;
213 rtx insn;
214 {
215 rtx next;
216
217 for (insn = NEXT_INSN (insn); insn; insn = next)
218 {
219 next = NEXT_INSN (insn);
220 if (GET_CODE (insn) == NOTE)
221 continue;
222 if (GET_CODE (insn) == CODE_LABEL
223 || GET_CODE (insn) == BARRIER)
224 return 0;
225 if (GET_CODE (insn) == INSN
226 || GET_CODE (insn) == JUMP_INSN
227 || GET_CODE (insn) == CALL_INSN)
228 {
229 if (reg_set_p (reg, insn))
230 return 0;
231 if (reg_mentioned_p (reg, PATTERN (insn)))
232 return insn;
233 if (GET_CODE (insn) == JUMP_INSN)
234 {
235 if (simplejump_p (insn))
236 next = JUMP_LABEL (insn);
237 else
238 return 0;
239 }
240 if (GET_CODE (insn) == CALL_INSN
241 && REGNO (reg) < FIRST_PSEUDO_REGISTER
242 && call_used_regs[REGNO (reg)])
243 return 0;
244 }
245 else
246 abort ();
247 }
248 return 0;
249 }
250
251 /* Return an rtx for the size in bytes of the value of EXP. */
252
253 rtx
254 expr_size (exp)
255 tree exp;
256 {
257 tree size = size_in_bytes (TREE_TYPE (exp));
258
259 if (TREE_CODE (size) != INTEGER_CST
260 && contains_placeholder_p (size))
261 size = build (WITH_RECORD_EXPR, sizetype, size, exp);
262
263 return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype),
264 EXPAND_MEMORY_USE_BAD);
265 }
266 \f
267 /* Return a copy of X in which all memory references
268 and all constants that involve symbol refs
269 have been replaced with new temporary registers.
270 Also emit code to load the memory locations and constants
271 into those registers.
272
273 If X contains no such constants or memory references,
274 X itself (not a copy) is returned.
275
276 If a constant is found in the address that is not a legitimate constant
277 in an insn, it is left alone in the hope that it might be valid in the
278 address.
279
280 X may contain no arithmetic except addition, subtraction and multiplication.
281 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
282
283 static rtx
284 break_out_memory_refs (x)
285 register rtx x;
286 {
287 if (GET_CODE (x) == MEM
288 || (CONSTANT_P (x) && CONSTANT_ADDRESS_P (x)
289 && GET_MODE (x) != VOIDmode))
290 x = force_reg (GET_MODE (x), x);
291 else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
292 || GET_CODE (x) == MULT)
293 {
294 register rtx op0 = break_out_memory_refs (XEXP (x, 0));
295 register rtx op1 = break_out_memory_refs (XEXP (x, 1));
296
297 if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
298 x = gen_rtx_fmt_ee (GET_CODE (x), Pmode, op0, op1);
299 }
300
301 return x;
302 }
303
304 #ifdef POINTERS_EXTEND_UNSIGNED
305
306 /* Given X, a memory address in ptr_mode, convert it to an address
307 in Pmode, or vice versa (TO_MODE says which way). We take advantage of
308 the fact that pointers are not allowed to overflow by commuting arithmetic
309 operations over conversions so that address arithmetic insns can be
310 used. */
311
312 rtx
313 convert_memory_address (to_mode, x)
314 enum machine_mode to_mode;
315 rtx x;
316 {
317 enum machine_mode from_mode = to_mode == ptr_mode ? Pmode : ptr_mode;
318 rtx temp;
319
320 /* Here we handle some special cases. If none of them apply, fall through
321 to the default case. */
322 switch (GET_CODE (x))
323 {
324 case CONST_INT:
325 case CONST_DOUBLE:
326 return x;
327
328 case LABEL_REF:
329 temp = gen_rtx_LABEL_REF (to_mode, XEXP (x, 0));
330 LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x);
331 return temp;
332
333 case SYMBOL_REF:
334 temp = gen_rtx_SYMBOL_REF (to_mode, XSTR (x, 0));
335 SYMBOL_REF_FLAG (temp) = SYMBOL_REF_FLAG (x);
336 CONSTANT_POOL_ADDRESS_P (temp) = CONSTANT_POOL_ADDRESS_P (x);
337 return temp;
338
339 case CONST:
340 return gen_rtx_CONST (to_mode,
341 convert_memory_address (to_mode, XEXP (x, 0)));
342
343 case PLUS:
344 case MULT:
345 /* For addition the second operand is a small constant, we can safely
346 permute the conversion and addition operation. We can always safely
347 permute them if we are making the address narrower. In addition,
348 always permute the operations if this is a constant. */
349 if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)
350 || (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == CONST_INT
351 && (INTVAL (XEXP (x, 1)) + 20000 < 40000
352 || CONSTANT_P (XEXP (x, 0)))))
353 return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
354 convert_memory_address (to_mode, XEXP (x, 0)),
355 convert_memory_address (to_mode, XEXP (x, 1)));
356 break;
357
358 default:
359 break;
360 }
361
362 return convert_modes (to_mode, from_mode,
363 x, POINTERS_EXTEND_UNSIGNED);
364 }
365 #endif
366
367 /* Given a memory address or facsimile X, construct a new address,
368 currently equivalent, that is stable: future stores won't change it.
369
370 X must be composed of constants, register and memory references
371 combined with addition, subtraction and multiplication:
372 in other words, just what you can get from expand_expr if sum_ok is 1.
373
374 Works by making copies of all regs and memory locations used
375 by X and combining them the same way X does.
376 You could also stabilize the reference to this address
377 by copying the address to a register with copy_to_reg;
378 but then you wouldn't get indexed addressing in the reference. */
379
380 rtx
381 copy_all_regs (x)
382 register rtx x;
383 {
384 if (GET_CODE (x) == REG)
385 {
386 if (REGNO (x) != FRAME_POINTER_REGNUM
387 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
388 && REGNO (x) != HARD_FRAME_POINTER_REGNUM
389 #endif
390 )
391 x = copy_to_reg (x);
392 }
393 else if (GET_CODE (x) == MEM)
394 x = copy_to_reg (x);
395 else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
396 || GET_CODE (x) == MULT)
397 {
398 register rtx op0 = copy_all_regs (XEXP (x, 0));
399 register rtx op1 = copy_all_regs (XEXP (x, 1));
400 if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
401 x = gen_rtx_fmt_ee (GET_CODE (x), Pmode, op0, op1);
402 }
403 return x;
404 }
405 \f
406 /* Return something equivalent to X but valid as a memory address
407 for something of mode MODE. When X is not itself valid, this
408 works by copying X or subexpressions of it into registers. */
409
410 rtx
411 memory_address (mode, x)
412 enum machine_mode mode;
413 register rtx x;
414 {
415 register rtx oldx = x;
416
417 if (GET_CODE (x) == ADDRESSOF)
418 return x;
419
420 #ifdef POINTERS_EXTEND_UNSIGNED
421 if (GET_MODE (x) == ptr_mode)
422 x = convert_memory_address (Pmode, x);
423 #endif
424
425 /* By passing constant addresses thru registers
426 we get a chance to cse them. */
427 if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x))
428 x = force_reg (Pmode, x);
429
430 /* Accept a QUEUED that refers to a REG
431 even though that isn't a valid address.
432 On attempting to put this in an insn we will call protect_from_queue
433 which will turn it into a REG, which is valid. */
434 else if (GET_CODE (x) == QUEUED
435 && GET_CODE (QUEUED_VAR (x)) == REG)
436 ;
437
438 /* We get better cse by rejecting indirect addressing at this stage.
439 Let the combiner create indirect addresses where appropriate.
440 For now, generate the code so that the subexpressions useful to share
441 are visible. But not if cse won't be done! */
442 else
443 {
444 if (! cse_not_expected && GET_CODE (x) != REG)
445 x = break_out_memory_refs (x);
446
447 /* At this point, any valid address is accepted. */
448 GO_IF_LEGITIMATE_ADDRESS (mode, x, win);
449
450 /* If it was valid before but breaking out memory refs invalidated it,
451 use it the old way. */
452 if (memory_address_p (mode, oldx))
453 goto win2;
454
455 /* Perform machine-dependent transformations on X
456 in certain cases. This is not necessary since the code
457 below can handle all possible cases, but machine-dependent
458 transformations can make better code. */
459 LEGITIMIZE_ADDRESS (x, oldx, mode, win);
460
461 /* PLUS and MULT can appear in special ways
462 as the result of attempts to make an address usable for indexing.
463 Usually they are dealt with by calling force_operand, below.
464 But a sum containing constant terms is special
465 if removing them makes the sum a valid address:
466 then we generate that address in a register
467 and index off of it. We do this because it often makes
468 shorter code, and because the addresses thus generated
469 in registers often become common subexpressions. */
470 if (GET_CODE (x) == PLUS)
471 {
472 rtx constant_term = const0_rtx;
473 rtx y = eliminate_constant_term (x, &constant_term);
474 if (constant_term == const0_rtx
475 || ! memory_address_p (mode, y))
476 x = force_operand (x, NULL_RTX);
477 else
478 {
479 y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term);
480 if (! memory_address_p (mode, y))
481 x = force_operand (x, NULL_RTX);
482 else
483 x = y;
484 }
485 }
486
487 else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS)
488 x = force_operand (x, NULL_RTX);
489
490 /* If we have a register that's an invalid address,
491 it must be a hard reg of the wrong class. Copy it to a pseudo. */
492 else if (GET_CODE (x) == REG)
493 x = copy_to_reg (x);
494
495 /* Last resort: copy the value to a register, since
496 the register is a valid address. */
497 else
498 x = force_reg (Pmode, x);
499
500 goto done;
501
502 win2:
503 x = oldx;
504 win:
505 if (flag_force_addr && ! cse_not_expected && GET_CODE (x) != REG
506 /* Don't copy an addr via a reg if it is one of our stack slots. */
507 && ! (GET_CODE (x) == PLUS
508 && (XEXP (x, 0) == virtual_stack_vars_rtx
509 || XEXP (x, 0) == virtual_incoming_args_rtx)))
510 {
511 if (general_operand (x, Pmode))
512 x = force_reg (Pmode, x);
513 else
514 x = force_operand (x, NULL_RTX);
515 }
516 }
517
518 done:
519
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;
524 else if (GET_CODE (x) == REG)
525 mark_reg_pointer (x, 1);
526 else if (GET_CODE (x) == PLUS
527 && GET_CODE (XEXP (x, 0)) == REG
528 && GET_CODE (XEXP (x, 1)) == CONST_INT)
529 mark_reg_pointer (XEXP (x, 0), 1);
530
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
535 return x;
536 }
537
538 /* Like `memory_address' but pretend `flag_force_addr' is 0. */
539
540 rtx
541 memory_address_noforce (mode, x)
542 enum machine_mode mode;
543 rtx x;
544 {
545 int ambient_force_addr = flag_force_addr;
546 rtx val;
547
548 flag_force_addr = 0;
549 val = memory_address (mode, x);
550 flag_force_addr = ambient_force_addr;
551 return val;
552 }
553
554 /* Convert a mem ref into one with a valid memory address.
555 Pass through anything else unchanged. */
556
557 rtx
558 validize_mem (ref)
559 rtx ref;
560 {
561 if (GET_CODE (ref) != MEM)
562 return ref;
563 if (memory_address_p (GET_MODE (ref), XEXP (ref, 0)))
564 return ref;
565 /* Don't alter REF itself, since that is probably a stack slot. */
566 return change_address (ref, GET_MODE (ref), XEXP (ref, 0));
567 }
568 \f
569 /* Return a modified copy of X with its memory address copied
570 into a temporary register to protect it from side effects.
571 If X is not a MEM, it is returned unchanged (and not copied).
572 Perhaps even if it is a MEM, if there is no need to change it. */
573
574 rtx
575 stabilize (x)
576 rtx x;
577 {
578 register rtx addr;
579 if (GET_CODE (x) != MEM)
580 return x;
581 addr = XEXP (x, 0);
582 if (rtx_unstable_p (addr))
583 {
584 rtx temp = copy_all_regs (addr);
585 rtx mem;
586 if (GET_CODE (temp) != REG)
587 temp = copy_to_reg (temp);
588 mem = gen_rtx_MEM (GET_MODE (x), temp);
589
590 /* Mark returned memref with in_struct if it's in an array or
591 structure. Copy const and volatile from original memref. */
592
593 MEM_IN_STRUCT_P (mem) = MEM_IN_STRUCT_P (x) || GET_CODE (addr) == PLUS;
594 RTX_UNCHANGING_P (mem) = RTX_UNCHANGING_P (x);
595 MEM_VOLATILE_P (mem) = MEM_VOLATILE_P (x);
596 return mem;
597 }
598 return x;
599 }
600 \f
601 /* Copy the value or contents of X to a new temp reg and return that reg. */
602
603 rtx
604 copy_to_reg (x)
605 rtx x;
606 {
607 register rtx temp = gen_reg_rtx (GET_MODE (x));
608
609 /* If not an operand, must be an address with PLUS and MULT so
610 do the computation. */
611 if (! general_operand (x, VOIDmode))
612 x = force_operand (x, temp);
613
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
623 rtx
624 copy_addr_to_reg (x)
625 rtx x;
626 {
627 return copy_to_mode_reg (Pmode, x);
628 }
629
630 /* Like copy_to_reg but always give the new register mode MODE
631 in case X is a constant. */
632
633 rtx
634 copy_to_mode_reg (mode, x)
635 enum machine_mode mode;
636 rtx x;
637 {
638 register rtx temp = gen_reg_rtx (mode);
639
640 /* If not an operand, must be an address with PLUS and MULT so
641 do the computation. */
642 if (! general_operand (x, VOIDmode))
643 x = force_operand (x, temp);
644
645 if (GET_MODE (x) != mode && GET_MODE (x) != VOIDmode)
646 abort ();
647 if (x != temp)
648 emit_move_insn (temp, x);
649 return temp;
650 }
651
652 /* Load X into a register if it is not already one.
653 Use mode MODE for the register.
654 X should be valid for mode MODE, but it may be a constant which
655 is valid for all integer modes; that's why caller must specify MODE.
656
657 The caller must not alter the value in the register we return,
658 since we mark it as a "constant" register. */
659
660 rtx
661 force_reg (mode, x)
662 enum machine_mode mode;
663 rtx x;
664 {
665 register rtx temp, insn, set;
666
667 if (GET_CODE (x) == REG)
668 return x;
669 temp = gen_reg_rtx (mode);
670 insn = emit_move_insn (temp, x);
671
672 /* Let optimizers know that TEMP's value never changes
673 and that X can be substituted for it. Don't get confused
674 if INSN set something else (such as a SUBREG of TEMP). */
675 if (CONSTANT_P (x)
676 && (set = single_set (insn)) != 0
677 && SET_DEST (set) == temp)
678 {
679 rtx note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
680
681 if (note)
682 XEXP (note, 0) = x;
683 else
684 REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUAL, x, REG_NOTES (insn));
685 }
686 return temp;
687 }
688
689 /* If X is a memory ref, copy its contents to a new temp reg and return
690 that reg. Otherwise, return X. */
691
692 rtx
693 force_not_mem (x)
694 rtx x;
695 {
696 register rtx temp;
697 if (GET_CODE (x) != MEM || GET_MODE (x) == BLKmode)
698 return x;
699 temp = gen_reg_rtx (GET_MODE (x));
700 emit_move_insn (temp, x);
701 return temp;
702 }
703
704 /* Copy X to TARGET (if it's nonzero and a reg)
705 or to a new temp reg and return that reg.
706 MODE is the mode to use for X in case it is a constant. */
707
708 rtx
709 copy_to_suggested_reg (x, target, mode)
710 rtx x, target;
711 enum machine_mode mode;
712 {
713 register rtx temp;
714
715 if (target && GET_CODE (target) == REG)
716 temp = target;
717 else
718 temp = gen_reg_rtx (mode);
719
720 emit_move_insn (temp, x);
721 return temp;
722 }
723 \f
724 /* Return the mode to use to store a scalar of TYPE and MODE.
725 PUNSIGNEDP points to the signedness of the type and may be adjusted
726 to show what signedness to use on extension operations.
727
728 FOR_CALL is non-zero if this call is promoting args for a call. */
729
730 enum machine_mode
731 promote_mode (type, mode, punsignedp, for_call)
732 tree type;
733 enum machine_mode mode;
734 int *punsignedp;
735 int for_call;
736 {
737 enum tree_code code = TREE_CODE (type);
738 int unsignedp = *punsignedp;
739
740 #ifdef PROMOTE_FOR_CALL_ONLY
741 if (! for_call)
742 return mode;
743 #endif
744
745 switch (code)
746 {
747 #ifdef PROMOTE_MODE
748 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
749 case CHAR_TYPE: case REAL_TYPE: case OFFSET_TYPE:
750 PROMOTE_MODE (mode, unsignedp, type);
751 break;
752 #endif
753
754 #ifdef POINTERS_EXTEND_UNSIGNED
755 case REFERENCE_TYPE:
756 case POINTER_TYPE:
757 mode = Pmode;
758 unsignedp = POINTERS_EXTEND_UNSIGNED;
759 break;
760 #endif
761
762 default:
763 break;
764 }
765
766 *punsignedp = unsignedp;
767 return mode;
768 }
769 \f
770 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
771 This pops when ADJUST is positive. ADJUST need not be constant. */
772
773 void
774 adjust_stack (adjust)
775 rtx adjust;
776 {
777 rtx temp;
778 adjust = protect_from_queue (adjust, 0);
779
780 if (adjust == const0_rtx)
781 return;
782
783 temp = expand_binop (Pmode,
784 #ifdef STACK_GROWS_DOWNWARD
785 add_optab,
786 #else
787 sub_optab,
788 #endif
789 stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
790 OPTAB_LIB_WIDEN);
791
792 if (temp != stack_pointer_rtx)
793 emit_move_insn (stack_pointer_rtx, temp);
794 }
795
796 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
797 This pushes when ADJUST is positive. ADJUST need not be constant. */
798
799 void
800 anti_adjust_stack (adjust)
801 rtx adjust;
802 {
803 rtx temp;
804 adjust = protect_from_queue (adjust, 0);
805
806 if (adjust == const0_rtx)
807 return;
808
809 temp = expand_binop (Pmode,
810 #ifdef STACK_GROWS_DOWNWARD
811 sub_optab,
812 #else
813 add_optab,
814 #endif
815 stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
816 OPTAB_LIB_WIDEN);
817
818 if (temp != stack_pointer_rtx)
819 emit_move_insn (stack_pointer_rtx, temp);
820 }
821
822 /* Round the size of a block to be pushed up to the boundary required
823 by this machine. SIZE is the desired size, which need not be constant. */
824
825 rtx
826 round_push (size)
827 rtx size;
828 {
829 #ifdef STACK_BOUNDARY
830 int align = STACK_BOUNDARY / BITS_PER_UNIT;
831 if (align == 1)
832 return size;
833 if (GET_CODE (size) == CONST_INT)
834 {
835 int new = (INTVAL (size) + align - 1) / align * align;
836 if (INTVAL (size) != new)
837 size = GEN_INT (new);
838 }
839 else
840 {
841 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
842 but we know it can't. So add ourselves and then do
843 TRUNC_DIV_EXPR. */
844 size = expand_binop (Pmode, add_optab, size, GEN_INT (align - 1),
845 NULL_RTX, 1, OPTAB_LIB_WIDEN);
846 size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, GEN_INT (align),
847 NULL_RTX, 1);
848 size = expand_mult (Pmode, size, GEN_INT (align), NULL_RTX, 1);
849 }
850 #endif /* STACK_BOUNDARY */
851 return size;
852 }
853 \f
854 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
855 to a previously-created save area. If no save area has been allocated,
856 this function will allocate one. If a save area is specified, it
857 must be of the proper mode.
858
859 The insns are emitted after insn AFTER, if nonzero, otherwise the insns
860 are emitted at the current position. */
861
862 void
863 emit_stack_save (save_level, psave, after)
864 enum save_level save_level;
865 rtx *psave;
866 rtx after;
867 {
868 rtx sa = *psave;
869 /* The default is that we use a move insn and save in a Pmode object. */
870 rtx (*fcn) () = gen_move_insn;
871 enum machine_mode mode = Pmode;
872
873 /* See if this machine has anything special to do for this kind of save. */
874 switch (save_level)
875 {
876 #ifdef HAVE_save_stack_block
877 case SAVE_BLOCK:
878 if (HAVE_save_stack_block)
879 {
880 fcn = gen_save_stack_block;
881 mode = insn_operand_mode[CODE_FOR_save_stack_block][0];
882 }
883 break;
884 #endif
885 #ifdef HAVE_save_stack_function
886 case SAVE_FUNCTION:
887 if (HAVE_save_stack_function)
888 {
889 fcn = gen_save_stack_function;
890 mode = insn_operand_mode[CODE_FOR_save_stack_function][0];
891 }
892 break;
893 #endif
894 #ifdef HAVE_save_stack_nonlocal
895 case SAVE_NONLOCAL:
896 if (HAVE_save_stack_nonlocal)
897 {
898 fcn = gen_save_stack_nonlocal;
899 mode = insn_operand_mode[(int) CODE_FOR_save_stack_nonlocal][0];
900 }
901 break;
902 #endif
903 default:
904 break;
905 }
906
907 /* If there is no save area and we have to allocate one, do so. Otherwise
908 verify the save area is the proper mode. */
909
910 if (sa == 0)
911 {
912 if (mode != VOIDmode)
913 {
914 if (save_level == SAVE_NONLOCAL)
915 *psave = sa = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
916 else
917 *psave = sa = gen_reg_rtx (mode);
918 }
919 }
920 else
921 {
922 if (mode == VOIDmode || GET_MODE (sa) != mode)
923 abort ();
924 }
925
926 if (after)
927 {
928 rtx seq;
929
930 start_sequence ();
931 /* We must validize inside the sequence, to ensure that any instructions
932 created by the validize call also get moved to the right place. */
933 if (sa != 0)
934 sa = validize_mem (sa);
935 emit_insn (fcn (sa, stack_pointer_rtx));
936 seq = gen_sequence ();
937 end_sequence ();
938 emit_insn_after (seq, after);
939 }
940 else
941 {
942 if (sa != 0)
943 sa = validize_mem (sa);
944 emit_insn (fcn (sa, stack_pointer_rtx));
945 }
946 }
947
948 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
949 area made by emit_stack_save. If it is zero, we have nothing to do.
950
951 Put any emitted insns after insn AFTER, if nonzero, otherwise at
952 current position. */
953
954 void
955 emit_stack_restore (save_level, sa, after)
956 enum save_level save_level;
957 rtx after;
958 rtx sa;
959 {
960 /* The default is that we use a move insn. */
961 rtx (*fcn) () = gen_move_insn;
962
963 /* See if this machine has anything special to do for this kind of save. */
964 switch (save_level)
965 {
966 #ifdef HAVE_restore_stack_block
967 case SAVE_BLOCK:
968 if (HAVE_restore_stack_block)
969 fcn = gen_restore_stack_block;
970 break;
971 #endif
972 #ifdef HAVE_restore_stack_function
973 case SAVE_FUNCTION:
974 if (HAVE_restore_stack_function)
975 fcn = gen_restore_stack_function;
976 break;
977 #endif
978 #ifdef HAVE_restore_stack_nonlocal
979
980 case SAVE_NONLOCAL:
981 if (HAVE_restore_stack_nonlocal)
982 fcn = gen_restore_stack_nonlocal;
983 break;
984 #endif
985 default:
986 break;
987 }
988
989 if (sa != 0)
990 sa = validize_mem (sa);
991
992 if (after)
993 {
994 rtx seq;
995
996 start_sequence ();
997 emit_insn (fcn (stack_pointer_rtx, sa));
998 seq = gen_sequence ();
999 end_sequence ();
1000 emit_insn_after (seq, after);
1001 }
1002 else
1003 emit_insn (fcn (stack_pointer_rtx, sa));
1004 }
1005 \f
1006 #ifdef SETJMP_VIA_SAVE_AREA
1007 /* Optimize RTL generated by allocate_dynamic_stack_space for targets
1008 where SETJMP_VIA_SAVE_AREA is true. The problem is that on these
1009 platforms, the dynamic stack space used can corrupt the original
1010 frame, thus causing a crash if a longjmp unwinds to it. */
1011
1012 void
1013 optimize_save_area_alloca (insns)
1014 rtx insns;
1015 {
1016 rtx insn;
1017
1018 for (insn = insns; insn; insn = NEXT_INSN(insn))
1019 {
1020 rtx note;
1021
1022 if (GET_CODE (insn) != INSN)
1023 continue;
1024
1025 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
1026 {
1027 if (REG_NOTE_KIND (note) != REG_SAVE_AREA)
1028 continue;
1029
1030 if (!current_function_calls_setjmp)
1031 {
1032 rtx pat = PATTERN (insn);
1033
1034 /* If we do not see the note in a pattern matching
1035 these precise characteristics, we did something
1036 entirely wrong in allocate_dynamic_stack_space.
1037
1038 Note, one way this could happen if if SETJMP_VIA_SAVE_AREA
1039 was defined on a machine where stacks grow towards higher
1040 addresses.
1041
1042 Right now only supported port with stack that grow upward
1043 is the HPPA and it does not define SETJMP_VIA_SAVE_AREA. */
1044 if (GET_CODE (pat) != SET
1045 || SET_DEST (pat) != stack_pointer_rtx
1046 || GET_CODE (SET_SRC (pat)) != MINUS
1047 || XEXP (SET_SRC (pat), 0) != stack_pointer_rtx)
1048 abort ();
1049
1050 /* This will now be transformed into a (set REG REG)
1051 so we can just blow away all the other notes. */
1052 XEXP (SET_SRC (pat), 1) = XEXP (note, 0);
1053 REG_NOTES (insn) = NULL_RTX;
1054 }
1055 else
1056 {
1057 /* setjmp was called, we must remove the REG_SAVE_AREA
1058 note so that later passes do not get confused by its
1059 presence. */
1060 if (note == REG_NOTES (insn))
1061 {
1062 REG_NOTES (insn) = XEXP (note, 1);
1063 }
1064 else
1065 {
1066 rtx srch;
1067
1068 for (srch = REG_NOTES (insn); srch; srch = XEXP (srch, 1))
1069 if (XEXP (srch, 1) == note)
1070 break;
1071
1072 if (srch == NULL_RTX)
1073 abort();
1074
1075 XEXP (srch, 1) = XEXP (note, 1);
1076 }
1077 }
1078 /* Once we've seen the note of interest, we need not look at
1079 the rest of them. */
1080 break;
1081 }
1082 }
1083 }
1084 #endif /* SETJMP_VIA_SAVE_AREA */
1085
1086 /* Return an rtx representing the address of an area of memory dynamically
1087 pushed on the stack. This region of memory is always aligned to
1088 a multiple of BIGGEST_ALIGNMENT.
1089
1090 Any required stack pointer alignment is preserved.
1091
1092 SIZE is an rtx representing the size of the area.
1093 TARGET is a place in which the address can be placed.
1094
1095 KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */
1096
1097 rtx
1098 allocate_dynamic_stack_space (size, target, known_align)
1099 rtx size;
1100 rtx target;
1101 int known_align;
1102 {
1103 #ifdef SETJMP_VIA_SAVE_AREA
1104 rtx setjmpless_size = NULL_RTX;
1105 #endif
1106
1107 /* If we're asking for zero bytes, it doesn't matter what we point
1108 to since we can't dereference it. But return a reasonable
1109 address anyway. */
1110 if (size == const0_rtx)
1111 return virtual_stack_dynamic_rtx;
1112
1113 /* Otherwise, show we're calling alloca or equivalent. */
1114 current_function_calls_alloca = 1;
1115
1116 /* Ensure the size is in the proper mode. */
1117 if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
1118 size = convert_to_mode (Pmode, size, 1);
1119
1120 /* We will need to ensure that the address we return is aligned to
1121 BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
1122 always know its final value at this point in the compilation (it
1123 might depend on the size of the outgoing parameter lists, for
1124 example), so we must align the value to be returned in that case.
1125 (Note that STACK_DYNAMIC_OFFSET will have a default non-zero value if
1126 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1127 We must also do an alignment operation on the returned value if
1128 the stack pointer alignment is less strict that BIGGEST_ALIGNMENT.
1129
1130 If we have to align, we must leave space in SIZE for the hole
1131 that might result from the alignment operation. */
1132
1133 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET) || ! defined (STACK_BOUNDARY)
1134 #define MUST_ALIGN 1
1135 #else
1136 #define MUST_ALIGN (STACK_BOUNDARY < BIGGEST_ALIGNMENT)
1137 #endif
1138
1139 if (MUST_ALIGN)
1140 {
1141 if (GET_CODE (size) == CONST_INT)
1142 size = GEN_INT (INTVAL (size)
1143 + (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1));
1144 else
1145 size = expand_binop (Pmode, add_optab, size,
1146 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
1147 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1148 }
1149
1150 #ifdef SETJMP_VIA_SAVE_AREA
1151 /* If setjmp restores regs from a save area in the stack frame,
1152 avoid clobbering the reg save area. Note that the offset of
1153 virtual_incoming_args_rtx includes the preallocated stack args space.
1154 It would be no problem to clobber that, but it's on the wrong side
1155 of the old save area. */
1156 {
1157 rtx dynamic_offset
1158 = expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx,
1159 stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN);
1160
1161 if (!current_function_calls_setjmp)
1162 {
1163 int align = STACK_BOUNDARY / BITS_PER_UNIT;
1164
1165 /* See optimize_save_area_alloca to understand what is being
1166 set up here. */
1167
1168 #if !defined(STACK_BOUNDARY) || !defined(MUST_ALIGN) || (STACK_BOUNDARY != BIGGEST_ALIGNMENT)
1169 /* If anyone creates a target with these characteristics, let them
1170 know that our optimization cannot work correctly in such a case. */
1171 abort();
1172 #endif
1173
1174 if (GET_CODE (size) == CONST_INT)
1175 {
1176 int new = INTVAL (size) / align * align;
1177
1178 if (INTVAL (size) != new)
1179 setjmpless_size = GEN_INT (new);
1180 else
1181 setjmpless_size = size;
1182 }
1183 else
1184 {
1185 /* Since we know overflow is not possible, we avoid using
1186 CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */
1187 setjmpless_size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size,
1188 GEN_INT (align), NULL_RTX, 1);
1189 setjmpless_size = expand_mult (Pmode, setjmpless_size,
1190 GEN_INT (align), NULL_RTX, 1);
1191 }
1192 /* Our optimization works based upon being able to perform a simple
1193 transformation of this RTL into a (set REG REG) so make sure things
1194 did in fact end up in a REG. */
1195 if (!arith_operand (setjmpless_size, Pmode))
1196 setjmpless_size = force_reg (Pmode, setjmpless_size);
1197 }
1198
1199 size = expand_binop (Pmode, add_optab, size, dynamic_offset,
1200 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1201 }
1202 #endif /* SETJMP_VIA_SAVE_AREA */
1203
1204 /* Round the size to a multiple of the required stack alignment.
1205 Since the stack if presumed to be rounded before this allocation,
1206 this will maintain the required alignment.
1207
1208 If the stack grows downward, we could save an insn by subtracting
1209 SIZE from the stack pointer and then aligning the stack pointer.
1210 The problem with this is that the stack pointer may be unaligned
1211 between the execution of the subtraction and alignment insns and
1212 some machines do not allow this. Even on those that do, some
1213 signal handlers malfunction if a signal should occur between those
1214 insns. Since this is an extremely rare event, we have no reliable
1215 way of knowing which systems have this problem. So we avoid even
1216 momentarily mis-aligning the stack. */
1217
1218 #ifdef STACK_BOUNDARY
1219 /* If we added a variable amount to SIZE,
1220 we can no longer assume it is aligned. */
1221 #if !defined (SETJMP_VIA_SAVE_AREA)
1222 if (MUST_ALIGN || known_align % STACK_BOUNDARY != 0)
1223 #endif
1224 size = round_push (size);
1225 #endif
1226
1227 do_pending_stack_adjust ();
1228
1229 /* If needed, check that we have the required amount of stack. Take into
1230 account what has already been checked. */
1231 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
1232 probe_stack_range (STACK_CHECK_MAX_FRAME_SIZE + STACK_CHECK_PROTECT, size);
1233
1234 /* Don't use a TARGET that isn't a pseudo. */
1235 if (target == 0 || GET_CODE (target) != REG
1236 || REGNO (target) < FIRST_PSEUDO_REGISTER)
1237 target = gen_reg_rtx (Pmode);
1238
1239 mark_reg_pointer (target, known_align / BITS_PER_UNIT);
1240
1241 /* Perform the required allocation from the stack. Some systems do
1242 this differently than simply incrementing/decrementing from the
1243 stack pointer, such as acquiring the space by calling malloc(). */
1244 #ifdef HAVE_allocate_stack
1245 if (HAVE_allocate_stack)
1246 {
1247 enum machine_mode mode;
1248
1249 if (insn_operand_predicate[(int) CODE_FOR_allocate_stack][0]
1250 && ! ((*insn_operand_predicate[(int) CODE_FOR_allocate_stack][0])
1251 (target, Pmode)))
1252 target = copy_to_mode_reg (Pmode, target);
1253 mode = insn_operand_mode[(int) CODE_FOR_allocate_stack][1];
1254 size = convert_modes (mode, ptr_mode, size, 1);
1255 if (insn_operand_predicate[(int) CODE_FOR_allocate_stack][1]
1256 && ! ((*insn_operand_predicate[(int) CODE_FOR_allocate_stack][1])
1257 (size, mode)))
1258 size = copy_to_mode_reg (mode, size);
1259
1260 emit_insn (gen_allocate_stack (target, size));
1261 }
1262 else
1263 #endif
1264 {
1265 #ifndef STACK_GROWS_DOWNWARD
1266 emit_move_insn (target, virtual_stack_dynamic_rtx);
1267 #endif
1268 size = convert_modes (Pmode, ptr_mode, size, 1);
1269 anti_adjust_stack (size);
1270 #ifdef SETJMP_VIA_SAVE_AREA
1271 if (setjmpless_size != NULL_RTX)
1272 {
1273 rtx note_target = get_last_insn ();
1274
1275 REG_NOTES (note_target) = gen_rtx (EXPR_LIST, REG_SAVE_AREA,
1276 setjmpless_size,
1277 REG_NOTES (note_target));
1278 }
1279 #endif /* SETJMP_VIA_SAVE_AREA */
1280 #ifdef STACK_GROWS_DOWNWARD
1281 emit_move_insn (target, virtual_stack_dynamic_rtx);
1282 #endif
1283 }
1284
1285 if (MUST_ALIGN)
1286 {
1287 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1288 but we know it can't. So add ourselves and then do
1289 TRUNC_DIV_EXPR. */
1290 target = expand_binop (Pmode, add_optab, target,
1291 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
1292 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1293 target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target,
1294 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
1295 NULL_RTX, 1);
1296 target = expand_mult (Pmode, target,
1297 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
1298 NULL_RTX, 1);
1299 }
1300
1301 /* Some systems require a particular insn to refer to the stack
1302 to make the pages exist. */
1303 #ifdef HAVE_probe
1304 if (HAVE_probe)
1305 emit_insn (gen_probe ());
1306 #endif
1307
1308 /* Record the new stack level for nonlocal gotos. */
1309 if (nonlocal_goto_handler_slot != 0)
1310 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
1311
1312 return target;
1313 }
1314 \f
1315 /* Emit one stack probe at ADDRESS, an address within the stack. */
1316
1317 static void
1318 emit_stack_probe (address)
1319 rtx address;
1320 {
1321 rtx memref = gen_rtx_MEM (word_mode, address);
1322
1323 MEM_VOLATILE_P (memref) = 1;
1324
1325 if (STACK_CHECK_PROBE_LOAD)
1326 emit_move_insn (gen_reg_rtx (word_mode), memref);
1327 else
1328 emit_move_insn (memref, const0_rtx);
1329 }
1330
1331 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1332 FIRST is a constant and size is a Pmode RTX. These are offsets from the
1333 current stack pointer. STACK_GROWS_DOWNWARD says whether to add or
1334 subtract from the stack. If SIZE is constant, this is done
1335 with a fixed number of probes. Otherwise, we must make a loop. */
1336
1337 #ifdef STACK_GROWS_DOWNWARD
1338 #define STACK_GROW_OP MINUS
1339 #else
1340 #define STACK_GROW_OP PLUS
1341 #endif
1342
1343 void
1344 probe_stack_range (first, size)
1345 HOST_WIDE_INT first;
1346 rtx size;
1347 {
1348 /* First see if we have an insn to check the stack. Use it if so. */
1349 #ifdef HAVE_check_stack
1350 if (HAVE_check_stack)
1351 {
1352 rtx last_addr
1353 = force_operand (gen_rtx_STACK_GROW_OP (Pmode,
1354 stack_pointer_rtx,
1355 plus_constant (size, first)),
1356 NULL_RTX);
1357
1358 if (insn_operand_predicate[(int) CODE_FOR_check_stack][0]
1359 && ! ((*insn_operand_predicate[(int) CODE_FOR_check_stack][0])
1360 (last_address, Pmode)))
1361 last_address = copy_to_mode_reg (Pmode, last_address);
1362
1363 emit_insn (gen_check_stack (last_address));
1364 return;
1365 }
1366 #endif
1367
1368 /* If we have to generate explicit probes, see if we have a constant
1369 small number of them to generate. If so, that's the easy case. */
1370 if (GET_CODE (size) == CONST_INT && INTVAL (size) < 10)
1371 {
1372 HOST_WIDE_INT offset;
1373
1374 /* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL
1375 for values of N from 1 until it exceeds LAST. If only one
1376 probe is needed, this will not generate any code. Then probe
1377 at LAST. */
1378 for (offset = first + STACK_CHECK_PROBE_INTERVAL;
1379 offset < INTVAL (size);
1380 offset = offset + STACK_CHECK_PROBE_INTERVAL)
1381 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1382 stack_pointer_rtx,
1383 GEN_INT (offset)));
1384
1385 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1386 stack_pointer_rtx,
1387 plus_constant (size, first)));
1388 }
1389
1390 /* In the variable case, do the same as above, but in a loop. We emit loop
1391 notes so that loop optimization can be done. */
1392 else
1393 {
1394 rtx test_addr
1395 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1396 stack_pointer_rtx,
1397 GEN_INT (first + STACK_CHECK_PROBE_INTERVAL)),
1398 NULL_RTX);
1399 rtx last_addr
1400 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1401 stack_pointer_rtx,
1402 plus_constant (size, first)),
1403 NULL_RTX);
1404 rtx incr = GEN_INT (STACK_CHECK_PROBE_INTERVAL);
1405 rtx loop_lab = gen_label_rtx ();
1406 rtx test_lab = gen_label_rtx ();
1407 rtx end_lab = gen_label_rtx ();
1408 rtx temp;
1409
1410 if (GET_CODE (test_addr) != REG
1411 || REGNO (test_addr) < FIRST_PSEUDO_REGISTER)
1412 test_addr = force_reg (Pmode, test_addr);
1413
1414 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
1415 emit_jump (test_lab);
1416
1417 emit_label (loop_lab);
1418 emit_stack_probe (test_addr);
1419
1420 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
1421
1422 #ifdef STACK_GROWS_DOWNWARD
1423 #define CMP_OPCODE GTU
1424 temp = expand_binop (Pmode, sub_optab, test_addr, incr, test_addr,
1425 1, OPTAB_WIDEN);
1426 #else
1427 #define CMP_OPCODE LTU
1428 temp = expand_binop (Pmode, add_optab, test_addr, incr, test_addr,
1429 1, OPTAB_WIDEN);
1430 #endif
1431
1432 if (temp != test_addr)
1433 abort ();
1434
1435 emit_label (test_lab);
1436 emit_cmp_insn (test_addr, last_addr, CMP_OPCODE, NULL_RTX, Pmode, 1, 0);
1437 emit_jump_insn ((*bcc_gen_fctn[(int) CMP_OPCODE]) (loop_lab));
1438 emit_jump (end_lab);
1439 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
1440 emit_label (end_lab);
1441
1442 /* If will be doing stupid optimization, show test_addr is still live. */
1443 if (obey_regdecls)
1444 emit_insn (gen_rtx_USE (VOIDmode, test_addr));
1445
1446 emit_stack_probe (last_addr);
1447 }
1448 }
1449 \f
1450 /* Return an rtx representing the register or memory location
1451 in which a scalar value of data type VALTYPE
1452 was returned by a function call to function FUNC.
1453 FUNC is a FUNCTION_DECL node if the precise function is known,
1454 otherwise 0. */
1455
1456 rtx
1457 hard_function_value (valtype, func)
1458 tree valtype;
1459 tree func;
1460 {
1461 rtx val = FUNCTION_VALUE (valtype, func);
1462 if (GET_CODE (val) == REG
1463 && GET_MODE (val) == BLKmode)
1464 {
1465 int bytes = int_size_in_bytes (valtype);
1466 enum machine_mode tmpmode;
1467 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
1468 tmpmode != MAX_MACHINE_MODE;
1469 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
1470 {
1471 /* Have we found a large enough mode? */
1472 if (GET_MODE_SIZE (tmpmode) >= bytes)
1473 break;
1474 }
1475
1476 /* No suitable mode found. */
1477 if (tmpmode == MAX_MACHINE_MODE)
1478 abort ();
1479
1480 PUT_MODE (val, tmpmode);
1481 }
1482 return val;
1483 }
1484
1485 /* Return an rtx representing the register or memory location
1486 in which a scalar value of mode MODE was returned by a library call. */
1487
1488 rtx
1489 hard_libcall_value (mode)
1490 enum machine_mode mode;
1491 {
1492 return LIBCALL_VALUE (mode);
1493 }
1494
1495 /* Look up the tree code for a given rtx code
1496 to provide the arithmetic operation for REAL_ARITHMETIC.
1497 The function returns an int because the caller may not know
1498 what `enum tree_code' means. */
1499
1500 int
1501 rtx_to_tree_code (code)
1502 enum rtx_code code;
1503 {
1504 enum tree_code tcode;
1505
1506 switch (code)
1507 {
1508 case PLUS:
1509 tcode = PLUS_EXPR;
1510 break;
1511 case MINUS:
1512 tcode = MINUS_EXPR;
1513 break;
1514 case MULT:
1515 tcode = MULT_EXPR;
1516 break;
1517 case DIV:
1518 tcode = RDIV_EXPR;
1519 break;
1520 case SMIN:
1521 tcode = MIN_EXPR;
1522 break;
1523 case SMAX:
1524 tcode = MAX_EXPR;
1525 break;
1526 default:
1527 tcode = LAST_AND_UNUSED_TREE_CODE;
1528 break;
1529 }
1530 return ((int) tcode);
1531 }