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1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987, 1991, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, USA. */
23 #include "config.h"
24 #include "system.h"
25 #include "coretypes.h"
26 #include "tm.h"
27 #include "toplev.h"
28 #include "rtl.h"
29 #include "tree.h"
30 #include "tm_p.h"
31 #include "flags.h"
32 #include "function.h"
33 #include "expr.h"
34 #include "optabs.h"
35 #include "hard-reg-set.h"
36 #include "insn-config.h"
37 #include "ggc.h"
38 #include "recog.h"
39 #include "langhooks.h"
41 static rtx break_out_memory_refs (rtx);
42 static void emit_stack_probe (rtx);
45 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
47 HOST_WIDE_INT
48 trunc_int_for_mode (HOST_WIDE_INT c, enum machine_mode mode)
50 int width = GET_MODE_BITSIZE (mode);
52 /* You want to truncate to a _what_? */
53 gcc_assert (SCALAR_INT_MODE_P (mode));
55 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
56 if (mode == BImode)
57 return c & 1 ? STORE_FLAG_VALUE : 0;
59 /* Sign-extend for the requested mode. */
61 if (width < HOST_BITS_PER_WIDE_INT)
63 HOST_WIDE_INT sign = 1;
64 sign <<= width - 1;
65 c &= (sign << 1) - 1;
66 c ^= sign;
67 c -= sign;
70 return c;
73 /* Return an rtx for the sum of X and the integer C. */
75 rtx
76 plus_constant (rtx x, HOST_WIDE_INT c)
78 RTX_CODE code;
79 rtx y;
80 enum machine_mode mode;
81 rtx tem;
82 int all_constant = 0;
84 if (c == 0)
85 return x;
87 restart:
89 code = GET_CODE (x);
90 mode = GET_MODE (x);
91 y = x;
93 switch (code)
95 case CONST_INT:
96 return GEN_INT (INTVAL (x) + c);
98 case CONST_DOUBLE:
100 unsigned HOST_WIDE_INT l1 = CONST_DOUBLE_LOW (x);
101 HOST_WIDE_INT h1 = CONST_DOUBLE_HIGH (x);
102 unsigned HOST_WIDE_INT l2 = c;
103 HOST_WIDE_INT h2 = c < 0 ? ~0 : 0;
104 unsigned HOST_WIDE_INT lv;
105 HOST_WIDE_INT hv;
107 add_double (l1, h1, l2, h2, &lv, &hv);
109 return immed_double_const (lv, hv, VOIDmode);
112 case MEM:
113 /* If this is a reference to the constant pool, try replacing it with
114 a reference to a new constant. If the resulting address isn't
115 valid, don't return it because we have no way to validize it. */
116 if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF
117 && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)))
120 = force_const_mem (GET_MODE (x),
121 plus_constant (get_pool_constant (XEXP (x, 0)),
122 c));
123 if (memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
124 return tem;
126 break;
128 case CONST:
129 /* If adding to something entirely constant, set a flag
130 so that we can add a CONST around the result. */
131 x = XEXP (x, 0);
132 all_constant = 1;
133 goto restart;
135 case SYMBOL_REF:
136 case LABEL_REF:
137 all_constant = 1;
138 break;
140 case PLUS:
141 /* The interesting case is adding the integer to a sum.
142 Look for constant term in the sum and combine
143 with C. For an integer constant term, we make a combined
144 integer. For a constant term that is not an explicit integer,
145 we cannot really combine, but group them together anyway.
147 Restart or use a recursive call in case the remaining operand is
148 something that we handle specially, such as a SYMBOL_REF.
150 We may not immediately return from the recursive call here, lest
151 all_constant gets lost. */
153 if (GET_CODE (XEXP (x, 1)) == CONST_INT)
155 c += INTVAL (XEXP (x, 1));
157 if (GET_MODE (x) != VOIDmode)
158 c = trunc_int_for_mode (c, GET_MODE (x));
160 x = XEXP (x, 0);
161 goto restart;
163 else if (CONSTANT_P (XEXP (x, 1)))
165 x = gen_rtx_PLUS (mode, XEXP (x, 0), plus_constant (XEXP (x, 1), c));
166 c = 0;
168 else if (find_constant_term_loc (&y))
170 /* We need to be careful since X may be shared and we can't
171 modify it in place. */
172 rtx copy = copy_rtx (x);
173 rtx *const_loc = find_constant_term_loc (&copy);
175 *const_loc = plus_constant (*const_loc, c);
176 x = copy;
177 c = 0;
179 break;
181 default:
182 break;
185 if (c != 0)
186 x = gen_rtx_PLUS (mode, x, GEN_INT (c));
188 if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
189 return x;
190 else if (all_constant)
191 return gen_rtx_CONST (mode, x);
192 else
193 return x;
196 /* If X is a sum, return a new sum like X but lacking any constant terms.
197 Add all the removed constant terms into *CONSTPTR.
198 X itself is not altered. The result != X if and only if
199 it is not isomorphic to X. */
202 eliminate_constant_term (rtx x, rtx *constptr)
204 rtx x0, x1;
205 rtx tem;
207 if (GET_CODE (x) != PLUS)
208 return x;
210 /* First handle constants appearing at this level explicitly. */
211 if (GET_CODE (XEXP (x, 1)) == CONST_INT
212 && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr,
213 XEXP (x, 1)))
214 && GET_CODE (tem) == CONST_INT)
216 *constptr = tem;
217 return eliminate_constant_term (XEXP (x, 0), constptr);
220 tem = const0_rtx;
221 x0 = eliminate_constant_term (XEXP (x, 0), &tem);
222 x1 = eliminate_constant_term (XEXP (x, 1), &tem);
223 if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0))
224 && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x),
225 *constptr, tem))
226 && GET_CODE (tem) == CONST_INT)
228 *constptr = tem;
229 return gen_rtx_PLUS (GET_MODE (x), x0, x1);
232 return x;
235 /* Return an rtx for the size in bytes of the value of EXP. */
238 expr_size (tree exp)
240 tree size;
242 if (TREE_CODE (exp) == WITH_SIZE_EXPR)
243 size = TREE_OPERAND (exp, 1);
244 else
245 size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (lang_hooks.expr_size (exp), exp);
247 return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype), 0);
250 /* Return a wide integer for the size in bytes of the value of EXP, or -1
251 if the size can vary or is larger than an integer. */
253 HOST_WIDE_INT
254 int_expr_size (tree exp)
256 tree size;
258 if (TREE_CODE (exp) == WITH_SIZE_EXPR)
259 size = TREE_OPERAND (exp, 1);
260 else
261 size = lang_hooks.expr_size (exp);
263 if (size == 0 || !host_integerp (size, 0))
264 return -1;
266 return tree_low_cst (size, 0);
269 /* Return a copy of X in which all memory references
270 and all constants that involve symbol refs
271 have been replaced with new temporary registers.
272 Also emit code to load the memory locations and constants
273 into those registers.
275 If X contains no such constants or memory references,
276 X itself (not a copy) is returned.
278 If a constant is found in the address that is not a legitimate constant
279 in an insn, it is left alone in the hope that it might be valid in the
280 address.
282 X may contain no arithmetic except addition, subtraction and multiplication.
283 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
285 static rtx
286 break_out_memory_refs (rtx x)
288 if (MEM_P (x)
289 || (CONSTANT_P (x) && CONSTANT_ADDRESS_P (x)
290 && GET_MODE (x) != VOIDmode))
291 x = force_reg (GET_MODE (x), x);
292 else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
293 || GET_CODE (x) == MULT)
295 rtx op0 = break_out_memory_refs (XEXP (x, 0));
296 rtx op1 = break_out_memory_refs (XEXP (x, 1));
298 if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
299 x = gen_rtx_fmt_ee (GET_CODE (x), Pmode, op0, op1);
302 return x;
305 /* Given X, a memory address in ptr_mode, convert it to an address
306 in Pmode, or vice versa (TO_MODE says which way). We take advantage of
307 the fact that pointers are not allowed to overflow by commuting arithmetic
308 operations over conversions so that address arithmetic insns can be
309 used. */
312 convert_memory_address (enum machine_mode to_mode ATTRIBUTE_UNUSED,
313 rtx x)
315 #ifndef POINTERS_EXTEND_UNSIGNED
316 return x;
317 #else /* defined(POINTERS_EXTEND_UNSIGNED) */
318 enum machine_mode from_mode;
319 rtx temp;
320 enum rtx_code code;
322 /* If X already has the right mode, just return it. */
323 if (GET_MODE (x) == to_mode)
324 return x;
326 from_mode = to_mode == ptr_mode ? Pmode : ptr_mode;
328 /* Here we handle some special cases. If none of them apply, fall through
329 to the default case. */
330 switch (GET_CODE (x))
332 case CONST_INT:
333 case CONST_DOUBLE:
334 if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode))
335 code = TRUNCATE;
336 else if (POINTERS_EXTEND_UNSIGNED < 0)
337 break;
338 else if (POINTERS_EXTEND_UNSIGNED > 0)
339 code = ZERO_EXTEND;
340 else
341 code = SIGN_EXTEND;
342 temp = simplify_unary_operation (code, to_mode, x, from_mode);
343 if (temp)
344 return temp;
345 break;
347 case SUBREG:
348 if ((SUBREG_PROMOTED_VAR_P (x) || REG_POINTER (SUBREG_REG (x)))
349 && GET_MODE (SUBREG_REG (x)) == to_mode)
350 return SUBREG_REG (x);
351 break;
353 case LABEL_REF:
354 temp = gen_rtx_LABEL_REF (to_mode, XEXP (x, 0));
355 LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x);
356 return temp;
357 break;
359 case SYMBOL_REF:
360 temp = shallow_copy_rtx (x);
361 PUT_MODE (temp, to_mode);
362 return temp;
363 break;
365 case CONST:
366 return gen_rtx_CONST (to_mode,
367 convert_memory_address (to_mode, XEXP (x, 0)));
368 break;
370 case PLUS:
371 case MULT:
372 /* For addition we can safely permute the conversion and addition
373 operation if one operand is a constant and converting the constant
374 does not change it. We can always safely permute them if we are
375 making the address narrower. */
376 if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)
377 || (GET_CODE (x) == PLUS
378 && GET_CODE (XEXP (x, 1)) == CONST_INT
379 && XEXP (x, 1) == convert_memory_address (to_mode, XEXP (x, 1))))
380 return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
381 convert_memory_address (to_mode, XEXP (x, 0)),
382 XEXP (x, 1));
383 break;
385 default:
386 break;
389 return convert_modes (to_mode, from_mode,
390 x, POINTERS_EXTEND_UNSIGNED);
391 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
394 /* Return something equivalent to X but valid as a memory address
395 for something of mode MODE. When X is not itself valid, this
396 works by copying X or subexpressions of it into registers. */
399 memory_address (enum machine_mode mode, rtx x)
401 rtx oldx = x;
403 x = convert_memory_address (Pmode, x);
405 /* By passing constant addresses through registers
406 we get a chance to cse them. */
407 if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x))
408 x = force_reg (Pmode, x);
410 /* We get better cse by rejecting indirect addressing at this stage.
411 Let the combiner create indirect addresses where appropriate.
412 For now, generate the code so that the subexpressions useful to share
413 are visible. But not if cse won't be done! */
414 else
416 if (! cse_not_expected && !REG_P (x))
417 x = break_out_memory_refs (x);
419 /* At this point, any valid address is accepted. */
420 if (memory_address_p (mode, x))
421 goto win;
423 /* If it was valid before but breaking out memory refs invalidated it,
424 use it the old way. */
425 if (memory_address_p (mode, oldx))
426 goto win2;
428 /* Perform machine-dependent transformations on X
429 in certain cases. This is not necessary since the code
430 below can handle all possible cases, but machine-dependent
431 transformations can make better code. */
432 LEGITIMIZE_ADDRESS (x, oldx, mode, win);
434 /* PLUS and MULT can appear in special ways
435 as the result of attempts to make an address usable for indexing.
436 Usually they are dealt with by calling force_operand, below.
437 But a sum containing constant terms is special
438 if removing them makes the sum a valid address:
439 then we generate that address in a register
440 and index off of it. We do this because it often makes
441 shorter code, and because the addresses thus generated
442 in registers often become common subexpressions. */
443 if (GET_CODE (x) == PLUS)
445 rtx constant_term = const0_rtx;
446 rtx y = eliminate_constant_term (x, &constant_term);
447 if (constant_term == const0_rtx
448 || ! memory_address_p (mode, y))
449 x = force_operand (x, NULL_RTX);
450 else
452 y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term);
453 if (! memory_address_p (mode, y))
454 x = force_operand (x, NULL_RTX);
455 else
456 x = y;
460 else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS)
461 x = force_operand (x, NULL_RTX);
463 /* If we have a register that's an invalid address,
464 it must be a hard reg of the wrong class. Copy it to a pseudo. */
465 else if (REG_P (x))
466 x = copy_to_reg (x);
468 /* Last resort: copy the value to a register, since
469 the register is a valid address. */
470 else
471 x = force_reg (Pmode, x);
473 goto done;
475 win2:
476 x = oldx;
477 win:
478 if (flag_force_addr && ! cse_not_expected && !REG_P (x)
479 /* Don't copy an addr via a reg if it is one of our stack slots. */
480 && ! (GET_CODE (x) == PLUS
481 && (XEXP (x, 0) == virtual_stack_vars_rtx
482 || XEXP (x, 0) == virtual_incoming_args_rtx)))
484 if (general_operand (x, Pmode))
485 x = force_reg (Pmode, x);
486 else
487 x = force_operand (x, NULL_RTX);
491 done:
493 /* If we didn't change the address, we are done. Otherwise, mark
494 a reg as a pointer if we have REG or REG + CONST_INT. */
495 if (oldx == x)
496 return x;
497 else if (REG_P (x))
498 mark_reg_pointer (x, BITS_PER_UNIT);
499 else if (GET_CODE (x) == PLUS
500 && REG_P (XEXP (x, 0))
501 && GET_CODE (XEXP (x, 1)) == CONST_INT)
502 mark_reg_pointer (XEXP (x, 0), BITS_PER_UNIT);
504 /* OLDX may have been the address on a temporary. Update the address
505 to indicate that X is now used. */
506 update_temp_slot_address (oldx, x);
508 return x;
511 /* Like `memory_address' but pretend `flag_force_addr' is 0. */
514 memory_address_noforce (enum machine_mode mode, rtx x)
516 int ambient_force_addr = flag_force_addr;
517 rtx val;
519 flag_force_addr = 0;
520 val = memory_address (mode, x);
521 flag_force_addr = ambient_force_addr;
522 return val;
525 /* Convert a mem ref into one with a valid memory address.
526 Pass through anything else unchanged. */
529 validize_mem (rtx ref)
531 if (!MEM_P (ref))
532 return ref;
533 if (! (flag_force_addr && CONSTANT_ADDRESS_P (XEXP (ref, 0)))
534 && memory_address_p (GET_MODE (ref), XEXP (ref, 0)))
535 return ref;
537 /* Don't alter REF itself, since that is probably a stack slot. */
538 return replace_equiv_address (ref, XEXP (ref, 0));
541 /* Copy the value or contents of X to a new temp reg and return that reg. */
544 copy_to_reg (rtx x)
546 rtx temp = gen_reg_rtx (GET_MODE (x));
548 /* If not an operand, must be an address with PLUS and MULT so
549 do the computation. */
550 if (! general_operand (x, VOIDmode))
551 x = force_operand (x, temp);
553 if (x != temp)
554 emit_move_insn (temp, x);
556 return temp;
559 /* Like copy_to_reg but always give the new register mode Pmode
560 in case X is a constant. */
563 copy_addr_to_reg (rtx x)
565 return copy_to_mode_reg (Pmode, x);
568 /* Like copy_to_reg but always give the new register mode MODE
569 in case X is a constant. */
572 copy_to_mode_reg (enum machine_mode mode, rtx x)
574 rtx temp = gen_reg_rtx (mode);
576 /* If not an operand, must be an address with PLUS and MULT so
577 do the computation. */
578 if (! general_operand (x, VOIDmode))
579 x = force_operand (x, temp);
581 gcc_assert (GET_MODE (x) == mode || GET_MODE (x) == VOIDmode);
582 if (x != temp)
583 emit_move_insn (temp, x);
584 return temp;
587 /* Load X into a register if it is not already one.
588 Use mode MODE for the register.
589 X should be valid for mode MODE, but it may be a constant which
590 is valid for all integer modes; that's why caller must specify MODE.
592 The caller must not alter the value in the register we return,
593 since we mark it as a "constant" register. */
596 force_reg (enum machine_mode mode, rtx x)
598 rtx temp, insn, set;
600 if (REG_P (x))
601 return x;
603 if (general_operand (x, mode))
605 temp = gen_reg_rtx (mode);
606 insn = emit_move_insn (temp, x);
608 else
610 temp = force_operand (x, NULL_RTX);
611 if (REG_P (temp))
612 insn = get_last_insn ();
613 else
615 rtx temp2 = gen_reg_rtx (mode);
616 insn = emit_move_insn (temp2, temp);
617 temp = temp2;
621 /* Let optimizers know that TEMP's value never changes
622 and that X can be substituted for it. Don't get confused
623 if INSN set something else (such as a SUBREG of TEMP). */
624 if (CONSTANT_P (x)
625 && (set = single_set (insn)) != 0
626 && SET_DEST (set) == temp
627 && ! rtx_equal_p (x, SET_SRC (set)))
628 set_unique_reg_note (insn, REG_EQUAL, x);
630 /* Let optimizers know that TEMP is a pointer, and if so, the
631 known alignment of that pointer. */
633 unsigned align = 0;
634 if (GET_CODE (x) == SYMBOL_REF)
636 align = BITS_PER_UNIT;
637 if (SYMBOL_REF_DECL (x) && DECL_P (SYMBOL_REF_DECL (x)))
638 align = DECL_ALIGN (SYMBOL_REF_DECL (x));
640 else if (GET_CODE (x) == LABEL_REF)
641 align = BITS_PER_UNIT;
642 else if (GET_CODE (x) == CONST
643 && GET_CODE (XEXP (x, 0)) == PLUS
644 && GET_CODE (XEXP (XEXP (x, 0), 0)) == SYMBOL_REF
645 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
647 rtx s = XEXP (XEXP (x, 0), 0);
648 rtx c = XEXP (XEXP (x, 0), 1);
649 unsigned sa, ca;
651 sa = BITS_PER_UNIT;
652 if (SYMBOL_REF_DECL (s) && DECL_P (SYMBOL_REF_DECL (s)))
653 sa = DECL_ALIGN (SYMBOL_REF_DECL (s));
655 ca = exact_log2 (INTVAL (c) & -INTVAL (c)) * BITS_PER_UNIT;
657 align = MIN (sa, ca);
660 if (align)
661 mark_reg_pointer (temp, align);
664 return temp;
667 /* If X is a memory ref, copy its contents to a new temp reg and return
668 that reg. Otherwise, return X. */
671 force_not_mem (rtx x)
673 rtx temp;
675 if (!MEM_P (x) || GET_MODE (x) == BLKmode)
676 return x;
678 temp = gen_reg_rtx (GET_MODE (x));
680 if (MEM_POINTER (x))
681 REG_POINTER (temp) = 1;
683 emit_move_insn (temp, x);
684 return temp;
687 /* Copy X to TARGET (if it's nonzero and a reg)
688 or to a new temp reg and return that reg.
689 MODE is the mode to use for X in case it is a constant. */
692 copy_to_suggested_reg (rtx x, rtx target, enum machine_mode mode)
694 rtx temp;
696 if (target && REG_P (target))
697 temp = target;
698 else
699 temp = gen_reg_rtx (mode);
701 emit_move_insn (temp, x);
702 return temp;
705 /* Return the mode to use to store a scalar of TYPE and MODE.
706 PUNSIGNEDP points to the signedness of the type and may be adjusted
707 to show what signedness to use on extension operations.
709 FOR_CALL is nonzero if this call is promoting args for a call. */
711 #if defined(PROMOTE_MODE) && !defined(PROMOTE_FUNCTION_MODE)
712 #define PROMOTE_FUNCTION_MODE PROMOTE_MODE
713 #endif
715 enum machine_mode
716 promote_mode (tree type, enum machine_mode mode, int *punsignedp,
717 int for_call ATTRIBUTE_UNUSED)
719 enum tree_code code = TREE_CODE (type);
720 int unsignedp = *punsignedp;
722 #ifndef PROMOTE_MODE
723 if (! for_call)
724 return mode;
725 #endif
727 switch (code)
729 #ifdef PROMOTE_FUNCTION_MODE
730 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
731 case CHAR_TYPE: case REAL_TYPE: case OFFSET_TYPE:
732 #ifdef PROMOTE_MODE
733 if (for_call)
735 #endif
736 PROMOTE_FUNCTION_MODE (mode, unsignedp, type);
737 #ifdef PROMOTE_MODE
739 else
741 PROMOTE_MODE (mode, unsignedp, type);
743 #endif
744 break;
745 #endif
747 #ifdef POINTERS_EXTEND_UNSIGNED
748 case REFERENCE_TYPE:
749 case POINTER_TYPE:
750 mode = Pmode;
751 unsignedp = POINTERS_EXTEND_UNSIGNED;
752 break;
753 #endif
755 default:
756 break;
759 *punsignedp = unsignedp;
760 return mode;
763 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
764 This pops when ADJUST is positive. ADJUST need not be constant. */
766 void
767 adjust_stack (rtx adjust)
769 rtx temp;
771 if (adjust == const0_rtx)
772 return;
774 /* We expect all variable sized adjustments to be multiple of
775 PREFERRED_STACK_BOUNDARY. */
776 if (GET_CODE (adjust) == CONST_INT)
777 stack_pointer_delta -= INTVAL (adjust);
779 temp = expand_binop (Pmode,
780 #ifdef STACK_GROWS_DOWNWARD
781 add_optab,
782 #else
783 sub_optab,
784 #endif
785 stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
786 OPTAB_LIB_WIDEN);
788 if (temp != stack_pointer_rtx)
789 emit_move_insn (stack_pointer_rtx, temp);
792 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
793 This pushes when ADJUST is positive. ADJUST need not be constant. */
795 void
796 anti_adjust_stack (rtx adjust)
798 rtx temp;
800 if (adjust == const0_rtx)
801 return;
803 /* We expect all variable sized adjustments to be multiple of
804 PREFERRED_STACK_BOUNDARY. */
805 if (GET_CODE (adjust) == CONST_INT)
806 stack_pointer_delta += INTVAL (adjust);
808 temp = expand_binop (Pmode,
809 #ifdef STACK_GROWS_DOWNWARD
810 sub_optab,
811 #else
812 add_optab,
813 #endif
814 stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
815 OPTAB_LIB_WIDEN);
817 if (temp != stack_pointer_rtx)
818 emit_move_insn (stack_pointer_rtx, temp);
821 /* Round the size of a block to be pushed up to the boundary required
822 by this machine. SIZE is the desired size, which need not be constant. */
824 static rtx
825 round_push (rtx size)
827 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
829 if (align == 1)
830 return size;
832 if (GET_CODE (size) == CONST_INT)
834 HOST_WIDE_INT new = (INTVAL (size) + align - 1) / align * align;
836 if (INTVAL (size) != new)
837 size = GEN_INT (new);
839 else
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);
851 return size;
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.
859 The insns are emitted after insn AFTER, if nonzero, otherwise the insns
860 are emitted at the current position. */
862 void
863 emit_stack_save (enum save_level save_level, rtx *psave, rtx after)
865 rtx sa = *psave;
866 /* The default is that we use a move insn and save in a Pmode object. */
867 rtx (*fcn) (rtx, rtx) = gen_move_insn;
868 enum machine_mode mode = STACK_SAVEAREA_MODE (save_level);
870 /* See if this machine has anything special to do for this kind of save. */
871 switch (save_level)
873 #ifdef HAVE_save_stack_block
874 case SAVE_BLOCK:
875 if (HAVE_save_stack_block)
876 fcn = gen_save_stack_block;
877 break;
878 #endif
879 #ifdef HAVE_save_stack_function
880 case SAVE_FUNCTION:
881 if (HAVE_save_stack_function)
882 fcn = gen_save_stack_function;
883 break;
884 #endif
885 #ifdef HAVE_save_stack_nonlocal
886 case SAVE_NONLOCAL:
887 if (HAVE_save_stack_nonlocal)
888 fcn = gen_save_stack_nonlocal;
889 break;
890 #endif
891 default:
892 break;
895 /* If there is no save area and we have to allocate one, do so. Otherwise
896 verify the save area is the proper mode. */
898 if (sa == 0)
900 if (mode != VOIDmode)
902 if (save_level == SAVE_NONLOCAL)
903 *psave = sa = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
904 else
905 *psave = sa = gen_reg_rtx (mode);
909 if (after)
911 rtx seq;
913 start_sequence ();
914 do_pending_stack_adjust ();
915 /* We must validize inside the sequence, to ensure that any instructions
916 created by the validize call also get moved to the right place. */
917 if (sa != 0)
918 sa = validize_mem (sa);
919 emit_insn (fcn (sa, stack_pointer_rtx));
920 seq = get_insns ();
921 end_sequence ();
922 emit_insn_after (seq, after);
924 else
926 do_pending_stack_adjust ();
927 if (sa != 0)
928 sa = validize_mem (sa);
929 emit_insn (fcn (sa, stack_pointer_rtx));
933 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
934 area made by emit_stack_save. If it is zero, we have nothing to do.
936 Put any emitted insns after insn AFTER, if nonzero, otherwise at
937 current position. */
939 void
940 emit_stack_restore (enum save_level save_level, rtx sa, rtx after)
942 /* The default is that we use a move insn. */
943 rtx (*fcn) (rtx, rtx) = gen_move_insn;
945 /* See if this machine has anything special to do for this kind of save. */
946 switch (save_level)
948 #ifdef HAVE_restore_stack_block
949 case SAVE_BLOCK:
950 if (HAVE_restore_stack_block)
951 fcn = gen_restore_stack_block;
952 break;
953 #endif
954 #ifdef HAVE_restore_stack_function
955 case SAVE_FUNCTION:
956 if (HAVE_restore_stack_function)
957 fcn = gen_restore_stack_function;
958 break;
959 #endif
960 #ifdef HAVE_restore_stack_nonlocal
961 case SAVE_NONLOCAL:
962 if (HAVE_restore_stack_nonlocal)
963 fcn = gen_restore_stack_nonlocal;
964 break;
965 #endif
966 default:
967 break;
970 if (sa != 0)
972 sa = validize_mem (sa);
973 /* These clobbers prevent the scheduler from moving
974 references to variable arrays below the code
975 that deletes (pops) the arrays. */
976 emit_insn (gen_rtx_CLOBBER (VOIDmode,
977 gen_rtx_MEM (BLKmode,
978 gen_rtx_SCRATCH (VOIDmode))));
979 emit_insn (gen_rtx_CLOBBER (VOIDmode,
980 gen_rtx_MEM (BLKmode, stack_pointer_rtx)));
983 discard_pending_stack_adjust ();
985 if (after)
987 rtx seq;
989 start_sequence ();
990 emit_insn (fcn (stack_pointer_rtx, sa));
991 seq = get_insns ();
992 end_sequence ();
993 emit_insn_after (seq, after);
995 else
996 emit_insn (fcn (stack_pointer_rtx, sa));
999 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1000 function. This function should be called whenever we allocate or
1001 deallocate dynamic stack space. */
1003 void
1004 update_nonlocal_goto_save_area (void)
1006 tree t_save;
1007 rtx r_save;
1009 /* The nonlocal_goto_save_area object is an array of N pointers. The
1010 first one is used for the frame pointer save; the rest are sized by
1011 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1012 of the stack save area slots. */
1013 t_save = build4 (ARRAY_REF, ptr_type_node, cfun->nonlocal_goto_save_area,
1014 integer_one_node, NULL_TREE, NULL_TREE);
1015 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
1017 emit_stack_save (SAVE_NONLOCAL, &r_save, NULL_RTX);
1020 #ifdef SETJMP_VIA_SAVE_AREA
1021 /* Optimize RTL generated by allocate_dynamic_stack_space for targets
1022 where SETJMP_VIA_SAVE_AREA is true. The problem is that on these
1023 platforms, the dynamic stack space used can corrupt the original
1024 frame, thus causing a crash if a longjmp unwinds to it. */
1026 void
1027 optimize_save_area_alloca (void)
1029 rtx insn;
1031 for (insn = get_insns (); insn; insn = NEXT_INSN(insn))
1033 rtx note;
1035 if (!NONJUMP_INSN_P (insn))
1036 continue;
1038 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
1040 if (REG_NOTE_KIND (note) != REG_SAVE_AREA)
1041 continue;
1043 if (!current_function_calls_setjmp)
1045 rtx pat = PATTERN (insn);
1047 /* If we do not see the note in a pattern matching
1048 these precise characteristics, we did something
1049 entirely wrong in allocate_dynamic_stack_space.
1051 Note, one way this could happen is if SETJMP_VIA_SAVE_AREA
1052 was defined on a machine where stacks grow towards higher
1053 addresses.
1055 Right now only supported port with stack that grow upward
1056 is the HPPA and it does not define SETJMP_VIA_SAVE_AREA. */
1057 gcc_assert (GET_CODE (pat) == SET
1058 && SET_DEST (pat) == stack_pointer_rtx
1059 && GET_CODE (SET_SRC (pat)) == MINUS
1060 && XEXP (SET_SRC (pat), 0) == stack_pointer_rtx);
1062 /* This will now be transformed into a (set REG REG)
1063 so we can just blow away all the other notes. */
1064 XEXP (SET_SRC (pat), 1) = XEXP (note, 0);
1065 REG_NOTES (insn) = NULL_RTX;
1067 else
1069 /* setjmp was called, we must remove the REG_SAVE_AREA
1070 note so that later passes do not get confused by its
1071 presence. */
1072 if (note == REG_NOTES (insn))
1074 REG_NOTES (insn) = XEXP (note, 1);
1076 else
1078 rtx srch;
1080 for (srch = REG_NOTES (insn); srch; srch = XEXP (srch, 1))
1081 if (XEXP (srch, 1) == note)
1082 break;
1084 gcc_assert (srch);
1086 XEXP (srch, 1) = XEXP (note, 1);
1089 /* Once we've seen the note of interest, we need not look at
1090 the rest of them. */
1091 break;
1095 #endif /* SETJMP_VIA_SAVE_AREA */
1097 /* Return an rtx representing the address of an area of memory dynamically
1098 pushed on the stack. This region of memory is always aligned to
1099 a multiple of BIGGEST_ALIGNMENT.
1101 Any required stack pointer alignment is preserved.
1103 SIZE is an rtx representing the size of the area.
1104 TARGET is a place in which the address can be placed.
1106 KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */
1109 allocate_dynamic_stack_space (rtx size, rtx target, int known_align)
1111 #ifdef SETJMP_VIA_SAVE_AREA
1112 rtx setjmpless_size = NULL_RTX;
1113 #endif
1115 /* If we're asking for zero bytes, it doesn't matter what we point
1116 to since we can't dereference it. But return a reasonable
1117 address anyway. */
1118 if (size == const0_rtx)
1119 return virtual_stack_dynamic_rtx;
1121 /* Otherwise, show we're calling alloca or equivalent. */
1122 current_function_calls_alloca = 1;
1124 /* Ensure the size is in the proper mode. */
1125 if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
1126 size = convert_to_mode (Pmode, size, 1);
1128 /* We can't attempt to minimize alignment necessary, because we don't
1129 know the final value of preferred_stack_boundary yet while executing
1130 this code. */
1131 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
1133 /* We will need to ensure that the address we return is aligned to
1134 BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
1135 always know its final value at this point in the compilation (it
1136 might depend on the size of the outgoing parameter lists, for
1137 example), so we must align the value to be returned in that case.
1138 (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
1139 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1140 We must also do an alignment operation on the returned value if
1141 the stack pointer alignment is less strict that BIGGEST_ALIGNMENT.
1143 If we have to align, we must leave space in SIZE for the hole
1144 that might result from the alignment operation. */
1146 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
1147 #define MUST_ALIGN 1
1148 #else
1149 #define MUST_ALIGN (PREFERRED_STACK_BOUNDARY < BIGGEST_ALIGNMENT)
1150 #endif
1152 if (MUST_ALIGN)
1153 size
1154 = force_operand (plus_constant (size,
1155 BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
1156 NULL_RTX);
1158 #ifdef SETJMP_VIA_SAVE_AREA
1159 /* If setjmp restores regs from a save area in the stack frame,
1160 avoid clobbering the reg save area. Note that the offset of
1161 virtual_incoming_args_rtx includes the preallocated stack args space.
1162 It would be no problem to clobber that, but it's on the wrong side
1163 of the old save area. */
1165 rtx dynamic_offset
1166 = expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx,
1167 stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN);
1169 if (!current_function_calls_setjmp)
1171 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
1173 /* See optimize_save_area_alloca to understand what is being
1174 set up here. */
1176 /* ??? Code below assumes that the save area needs maximal
1177 alignment. This constraint may be too strong. */
1178 gcc_assert (PREFERRED_STACK_BOUNDARY == BIGGEST_ALIGNMENT);
1180 if (GET_CODE (size) == CONST_INT)
1182 HOST_WIDE_INT new = INTVAL (size) / align * align;
1184 if (INTVAL (size) != new)
1185 setjmpless_size = GEN_INT (new);
1186 else
1187 setjmpless_size = size;
1189 else
1191 /* Since we know overflow is not possible, we avoid using
1192 CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */
1193 setjmpless_size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size,
1194 GEN_INT (align), NULL_RTX, 1);
1195 setjmpless_size = expand_mult (Pmode, setjmpless_size,
1196 GEN_INT (align), NULL_RTX, 1);
1198 /* Our optimization works based upon being able to perform a simple
1199 transformation of this RTL into a (set REG REG) so make sure things
1200 did in fact end up in a REG. */
1201 if (!register_operand (setjmpless_size, Pmode))
1202 setjmpless_size = force_reg (Pmode, setjmpless_size);
1205 size = expand_binop (Pmode, add_optab, size, dynamic_offset,
1206 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1208 #endif /* SETJMP_VIA_SAVE_AREA */
1210 /* Round the size to a multiple of the required stack alignment.
1211 Since the stack if presumed to be rounded before this allocation,
1212 this will maintain the required alignment.
1214 If the stack grows downward, we could save an insn by subtracting
1215 SIZE from the stack pointer and then aligning the stack pointer.
1216 The problem with this is that the stack pointer may be unaligned
1217 between the execution of the subtraction and alignment insns and
1218 some machines do not allow this. Even on those that do, some
1219 signal handlers malfunction if a signal should occur between those
1220 insns. Since this is an extremely rare event, we have no reliable
1221 way of knowing which systems have this problem. So we avoid even
1222 momentarily mis-aligning the stack. */
1224 /* If we added a variable amount to SIZE,
1225 we can no longer assume it is aligned. */
1226 #if !defined (SETJMP_VIA_SAVE_AREA)
1227 if (MUST_ALIGN || known_align % PREFERRED_STACK_BOUNDARY != 0)
1228 #endif
1229 size = round_push (size);
1231 do_pending_stack_adjust ();
1233 /* We ought to be called always on the toplevel and stack ought to be aligned
1234 properly. */
1235 gcc_assert (!(stack_pointer_delta
1236 % (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)));
1238 /* If needed, check that we have the required amount of stack. Take into
1239 account what has already been checked. */
1240 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
1241 probe_stack_range (STACK_CHECK_MAX_FRAME_SIZE + STACK_CHECK_PROTECT, size);
1243 /* Don't use a TARGET that isn't a pseudo or is the wrong mode. */
1244 if (target == 0 || !REG_P (target)
1245 || REGNO (target) < FIRST_PSEUDO_REGISTER
1246 || GET_MODE (target) != Pmode)
1247 target = gen_reg_rtx (Pmode);
1249 mark_reg_pointer (target, known_align);
1251 /* Perform the required allocation from the stack. Some systems do
1252 this differently than simply incrementing/decrementing from the
1253 stack pointer, such as acquiring the space by calling malloc(). */
1254 #ifdef HAVE_allocate_stack
1255 if (HAVE_allocate_stack)
1257 enum machine_mode mode = STACK_SIZE_MODE;
1258 insn_operand_predicate_fn pred;
1260 /* We don't have to check against the predicate for operand 0 since
1261 TARGET is known to be a pseudo of the proper mode, which must
1262 be valid for the operand. For operand 1, convert to the
1263 proper mode and validate. */
1264 if (mode == VOIDmode)
1265 mode = insn_data[(int) CODE_FOR_allocate_stack].operand[1].mode;
1267 pred = insn_data[(int) CODE_FOR_allocate_stack].operand[1].predicate;
1268 if (pred && ! ((*pred) (size, mode)))
1269 size = copy_to_mode_reg (mode, convert_to_mode (mode, size, 1));
1271 emit_insn (gen_allocate_stack (target, size));
1273 else
1274 #endif
1276 #ifndef STACK_GROWS_DOWNWARD
1277 emit_move_insn (target, virtual_stack_dynamic_rtx);
1278 #endif
1280 /* Check stack bounds if necessary. */
1281 if (current_function_limit_stack)
1283 rtx available;
1284 rtx space_available = gen_label_rtx ();
1285 #ifdef STACK_GROWS_DOWNWARD
1286 available = expand_binop (Pmode, sub_optab,
1287 stack_pointer_rtx, stack_limit_rtx,
1288 NULL_RTX, 1, OPTAB_WIDEN);
1289 #else
1290 available = expand_binop (Pmode, sub_optab,
1291 stack_limit_rtx, stack_pointer_rtx,
1292 NULL_RTX, 1, OPTAB_WIDEN);
1293 #endif
1294 emit_cmp_and_jump_insns (available, size, GEU, NULL_RTX, Pmode, 1,
1295 space_available);
1296 #ifdef HAVE_trap
1297 if (HAVE_trap)
1298 emit_insn (gen_trap ());
1299 else
1300 #endif
1301 error ("stack limits not supported on this target");
1302 emit_barrier ();
1303 emit_label (space_available);
1306 anti_adjust_stack (size);
1307 #ifdef SETJMP_VIA_SAVE_AREA
1308 if (setjmpless_size != NULL_RTX)
1310 rtx note_target = get_last_insn ();
1312 REG_NOTES (note_target)
1313 = gen_rtx_EXPR_LIST (REG_SAVE_AREA, setjmpless_size,
1314 REG_NOTES (note_target));
1316 #endif /* SETJMP_VIA_SAVE_AREA */
1318 #ifdef STACK_GROWS_DOWNWARD
1319 emit_move_insn (target, virtual_stack_dynamic_rtx);
1320 #endif
1323 if (MUST_ALIGN)
1325 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1326 but we know it can't. So add ourselves and then do
1327 TRUNC_DIV_EXPR. */
1328 target = expand_binop (Pmode, add_optab, target,
1329 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
1330 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1331 target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target,
1332 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
1333 NULL_RTX, 1);
1334 target = expand_mult (Pmode, target,
1335 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
1336 NULL_RTX, 1);
1339 /* Record the new stack level for nonlocal gotos. */
1340 if (cfun->nonlocal_goto_save_area != 0)
1341 update_nonlocal_goto_save_area ();
1343 return target;
1346 /* A front end may want to override GCC's stack checking by providing a
1347 run-time routine to call to check the stack, so provide a mechanism for
1348 calling that routine. */
1350 static GTY(()) rtx stack_check_libfunc;
1352 void
1353 set_stack_check_libfunc (rtx libfunc)
1355 stack_check_libfunc = libfunc;
1358 /* Emit one stack probe at ADDRESS, an address within the stack. */
1360 static void
1361 emit_stack_probe (rtx address)
1363 rtx memref = gen_rtx_MEM (word_mode, address);
1365 MEM_VOLATILE_P (memref) = 1;
1367 if (STACK_CHECK_PROBE_LOAD)
1368 emit_move_insn (gen_reg_rtx (word_mode), memref);
1369 else
1370 emit_move_insn (memref, const0_rtx);
1373 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1374 FIRST is a constant and size is a Pmode RTX. These are offsets from the
1375 current stack pointer. STACK_GROWS_DOWNWARD says whether to add or
1376 subtract from the stack. If SIZE is constant, this is done
1377 with a fixed number of probes. Otherwise, we must make a loop. */
1379 #ifdef STACK_GROWS_DOWNWARD
1380 #define STACK_GROW_OP MINUS
1381 #else
1382 #define STACK_GROW_OP PLUS
1383 #endif
1385 void
1386 probe_stack_range (HOST_WIDE_INT first, rtx size)
1388 /* First ensure SIZE is Pmode. */
1389 if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
1390 size = convert_to_mode (Pmode, size, 1);
1392 /* Next see if the front end has set up a function for us to call to
1393 check the stack. */
1394 if (stack_check_libfunc != 0)
1396 rtx addr = memory_address (QImode,
1397 gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1398 stack_pointer_rtx,
1399 plus_constant (size, first)));
1401 addr = convert_memory_address (ptr_mode, addr);
1402 emit_library_call (stack_check_libfunc, LCT_NORMAL, VOIDmode, 1, addr,
1403 ptr_mode);
1406 /* Next see if we have an insn to check the stack. Use it if so. */
1407 #ifdef HAVE_check_stack
1408 else if (HAVE_check_stack)
1410 insn_operand_predicate_fn pred;
1411 rtx last_addr
1412 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1413 stack_pointer_rtx,
1414 plus_constant (size, first)),
1415 NULL_RTX);
1417 pred = insn_data[(int) CODE_FOR_check_stack].operand[0].predicate;
1418 if (pred && ! ((*pred) (last_addr, Pmode)))
1419 last_addr = copy_to_mode_reg (Pmode, last_addr);
1421 emit_insn (gen_check_stack (last_addr));
1423 #endif
1425 /* If we have to generate explicit probes, see if we have a constant
1426 small number of them to generate. If so, that's the easy case. */
1427 else if (GET_CODE (size) == CONST_INT
1428 && INTVAL (size) < 10 * STACK_CHECK_PROBE_INTERVAL)
1430 HOST_WIDE_INT offset;
1432 /* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL
1433 for values of N from 1 until it exceeds LAST. If only one
1434 probe is needed, this will not generate any code. Then probe
1435 at LAST. */
1436 for (offset = first + STACK_CHECK_PROBE_INTERVAL;
1437 offset < INTVAL (size);
1438 offset = offset + STACK_CHECK_PROBE_INTERVAL)
1439 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1440 stack_pointer_rtx,
1441 GEN_INT (offset)));
1443 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1444 stack_pointer_rtx,
1445 plus_constant (size, first)));
1448 /* In the variable case, do the same as above, but in a loop. We emit loop
1449 notes so that loop optimization can be done. */
1450 else
1452 rtx test_addr
1453 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1454 stack_pointer_rtx,
1455 GEN_INT (first + STACK_CHECK_PROBE_INTERVAL)),
1456 NULL_RTX);
1457 rtx last_addr
1458 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1459 stack_pointer_rtx,
1460 plus_constant (size, first)),
1461 NULL_RTX);
1462 rtx incr = GEN_INT (STACK_CHECK_PROBE_INTERVAL);
1463 rtx loop_lab = gen_label_rtx ();
1464 rtx test_lab = gen_label_rtx ();
1465 rtx end_lab = gen_label_rtx ();
1466 rtx temp;
1468 if (!REG_P (test_addr)
1469 || REGNO (test_addr) < FIRST_PSEUDO_REGISTER)
1470 test_addr = force_reg (Pmode, test_addr);
1472 emit_jump (test_lab);
1474 emit_label (loop_lab);
1475 emit_stack_probe (test_addr);
1477 #ifdef STACK_GROWS_DOWNWARD
1478 #define CMP_OPCODE GTU
1479 temp = expand_binop (Pmode, sub_optab, test_addr, incr, test_addr,
1480 1, OPTAB_WIDEN);
1481 #else
1482 #define CMP_OPCODE LTU
1483 temp = expand_binop (Pmode, add_optab, test_addr, incr, test_addr,
1484 1, OPTAB_WIDEN);
1485 #endif
1487 gcc_assert (temp == test_addr);
1489 emit_label (test_lab);
1490 emit_cmp_and_jump_insns (test_addr, last_addr, CMP_OPCODE,
1491 NULL_RTX, Pmode, 1, loop_lab);
1492 emit_jump (end_lab);
1493 emit_label (end_lab);
1495 emit_stack_probe (last_addr);
1499 /* Return an rtx representing the register or memory location
1500 in which a scalar value of data type VALTYPE
1501 was returned by a function call to function FUNC.
1502 FUNC is a FUNCTION_DECL node if the precise function is known,
1503 otherwise 0.
1504 OUTGOING is 1 if on a machine with register windows this function
1505 should return the register in which the function will put its result
1506 and 0 otherwise. */
1509 hard_function_value (tree valtype, tree func ATTRIBUTE_UNUSED,
1510 int outgoing ATTRIBUTE_UNUSED)
1512 rtx val;
1514 #ifdef FUNCTION_OUTGOING_VALUE
1515 if (outgoing)
1516 val = FUNCTION_OUTGOING_VALUE (valtype, func);
1517 else
1518 #endif
1519 val = FUNCTION_VALUE (valtype, func);
1521 if (REG_P (val)
1522 && GET_MODE (val) == BLKmode)
1524 unsigned HOST_WIDE_INT bytes = int_size_in_bytes (valtype);
1525 enum machine_mode tmpmode;
1527 /* int_size_in_bytes can return -1. We don't need a check here
1528 since the value of bytes will be large enough that no mode
1529 will match and we will abort later in this function. */
1531 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
1532 tmpmode != VOIDmode;
1533 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
1535 /* Have we found a large enough mode? */
1536 if (GET_MODE_SIZE (tmpmode) >= bytes)
1537 break;
1540 /* No suitable mode found. */
1541 gcc_assert (tmpmode != VOIDmode);
1543 PUT_MODE (val, tmpmode);
1545 return val;
1548 /* Return an rtx representing the register or memory location
1549 in which a scalar value of mode MODE was returned by a library call. */
1552 hard_libcall_value (enum machine_mode mode)
1554 return LIBCALL_VALUE (mode);
1557 /* Look up the tree code for a given rtx code
1558 to provide the arithmetic operation for REAL_ARITHMETIC.
1559 The function returns an int because the caller may not know
1560 what `enum tree_code' means. */
1563 rtx_to_tree_code (enum rtx_code code)
1565 enum tree_code tcode;
1567 switch (code)
1569 case PLUS:
1570 tcode = PLUS_EXPR;
1571 break;
1572 case MINUS:
1573 tcode = MINUS_EXPR;
1574 break;
1575 case MULT:
1576 tcode = MULT_EXPR;
1577 break;
1578 case DIV:
1579 tcode = RDIV_EXPR;
1580 break;
1581 case SMIN:
1582 tcode = MIN_EXPR;
1583 break;
1584 case SMAX:
1585 tcode = MAX_EXPR;
1586 break;
1587 default:
1588 tcode = LAST_AND_UNUSED_TREE_CODE;
1589 break;
1591 return ((int) tcode);
1594 #include "gt-explow.h"