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[official-gcc/Ramakrishna.git] / gcc / explow.c
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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, 2006, 2007, 2008
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
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 "except.h"
33 #include "function.h"
34 #include "expr.h"
35 #include "optabs.h"
36 #include "hard-reg-set.h"
37 #include "insn-config.h"
38 #include "ggc.h"
39 #include "recog.h"
40 #include "langhooks.h"
41 #include "target.h"
42 #include "output.h"
44 static rtx break_out_memory_refs (rtx);
45 static void emit_stack_probe (rtx);
48 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
50 HOST_WIDE_INT
51 trunc_int_for_mode (HOST_WIDE_INT c, enum machine_mode mode)
53 int width = GET_MODE_BITSIZE (mode);
55 /* You want to truncate to a _what_? */
56 gcc_assert (SCALAR_INT_MODE_P (mode));
58 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
59 if (mode == BImode)
60 return c & 1 ? STORE_FLAG_VALUE : 0;
62 /* Sign-extend for the requested mode. */
64 if (width < HOST_BITS_PER_WIDE_INT)
66 HOST_WIDE_INT sign = 1;
67 sign <<= width - 1;
68 c &= (sign << 1) - 1;
69 c ^= sign;
70 c -= sign;
73 return c;
76 /* Return an rtx for the sum of X and the integer C. */
78 rtx
79 plus_constant (rtx x, HOST_WIDE_INT c)
81 RTX_CODE code;
82 rtx y;
83 enum machine_mode mode;
84 rtx tem;
85 int all_constant = 0;
87 if (c == 0)
88 return x;
90 restart:
92 code = GET_CODE (x);
93 mode = GET_MODE (x);
94 y = x;
96 switch (code)
98 case CONST_INT:
99 return GEN_INT (INTVAL (x) + c);
101 case CONST_DOUBLE:
103 unsigned HOST_WIDE_INT l1 = CONST_DOUBLE_LOW (x);
104 HOST_WIDE_INT h1 = CONST_DOUBLE_HIGH (x);
105 unsigned HOST_WIDE_INT l2 = c;
106 HOST_WIDE_INT h2 = c < 0 ? ~0 : 0;
107 unsigned HOST_WIDE_INT lv;
108 HOST_WIDE_INT hv;
110 add_double (l1, h1, l2, h2, &lv, &hv);
112 return immed_double_const (lv, hv, VOIDmode);
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)))
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;
129 break;
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;
138 case SYMBOL_REF:
139 case LABEL_REF:
140 all_constant = 1;
141 break;
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,
148 we cannot really combine, but group them together anyway.
150 Restart or use a recursive call in case the remaining operand is
151 something that we handle specially, such as a SYMBOL_REF.
153 We may not immediately return from the recursive call here, lest
154 all_constant gets lost. */
156 if (CONST_INT_P (XEXP (x, 1)))
158 c += INTVAL (XEXP (x, 1));
160 if (GET_MODE (x) != VOIDmode)
161 c = trunc_int_for_mode (c, GET_MODE (x));
163 x = XEXP (x, 0);
164 goto restart;
166 else if (CONSTANT_P (XEXP (x, 1)))
168 x = gen_rtx_PLUS (mode, XEXP (x, 0), plus_constant (XEXP (x, 1), c));
169 c = 0;
171 else if (find_constant_term_loc (&y))
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);
178 *const_loc = plus_constant (*const_loc, c);
179 x = copy;
180 c = 0;
182 break;
184 default:
185 break;
188 if (c != 0)
189 x = gen_rtx_PLUS (mode, x, GEN_INT (c));
191 if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
192 return x;
193 else if (all_constant)
194 return gen_rtx_CONST (mode, x);
195 else
196 return x;
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. */
205 eliminate_constant_term (rtx x, rtx *constptr)
207 rtx x0, x1;
208 rtx tem;
210 if (GET_CODE (x) != PLUS)
211 return x;
213 /* First handle constants appearing at this level explicitly. */
214 if (CONST_INT_P (XEXP (x, 1))
215 && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr,
216 XEXP (x, 1)))
217 && CONST_INT_P (tem))
219 *constptr = tem;
220 return eliminate_constant_term (XEXP (x, 0), constptr);
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 && CONST_INT_P (tem))
231 *constptr = tem;
232 return gen_rtx_PLUS (GET_MODE (x), x0, x1);
235 return x;
238 /* Return an rtx for the size in bytes of the value of EXP. */
241 expr_size (tree exp)
243 tree size;
245 if (TREE_CODE (exp) == WITH_SIZE_EXPR)
246 size = TREE_OPERAND (exp, 1);
247 else
249 size = tree_expr_size (exp);
250 gcc_assert (size);
251 gcc_assert (size == SUBSTITUTE_PLACEHOLDER_IN_EXPR (size, exp));
254 return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype), EXPAND_NORMAL);
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. */
260 HOST_WIDE_INT
261 int_expr_size (tree exp)
263 tree size;
265 if (TREE_CODE (exp) == WITH_SIZE_EXPR)
266 size = TREE_OPERAND (exp, 1);
267 else
269 size = tree_expr_size (exp);
270 gcc_assert (size);
273 if (size == 0 || !host_integerp (size, 0))
274 return -1;
276 return tree_low_cst (size, 0);
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.
285 If X contains no such constants or memory references,
286 X itself (not a copy) is returned.
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.
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. */
295 static rtx
296 break_out_memory_refs (rtx x)
298 if (MEM_P (x)
299 || (CONSTANT_P (x) && CONSTANT_ADDRESS_P (x)
300 && GET_MODE (x) != VOIDmode))
301 x = force_reg (GET_MODE (x), x);
302 else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
303 || GET_CODE (x) == MULT)
305 rtx op0 = break_out_memory_refs (XEXP (x, 0));
306 rtx op1 = break_out_memory_refs (XEXP (x, 1));
308 if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
309 x = simplify_gen_binary (GET_CODE (x), Pmode, op0, op1);
312 return x;
315 /* Given X, a memory address in ptr_mode, convert it to an address
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. */
322 convert_memory_address (enum machine_mode to_mode ATTRIBUTE_UNUSED,
323 rtx x)
325 #ifndef POINTERS_EXTEND_UNSIGNED
326 gcc_assert (GET_MODE (x) == to_mode || GET_MODE (x) == VOIDmode);
327 return x;
328 #else /* defined(POINTERS_EXTEND_UNSIGNED) */
329 enum machine_mode from_mode;
330 rtx temp;
331 enum rtx_code code;
333 /* If X already has the right mode, just return it. */
334 if (GET_MODE (x) == to_mode)
335 return x;
337 from_mode = to_mode == ptr_mode ? Pmode : ptr_mode;
339 /* Here we handle some special cases. If none of them apply, fall through
340 to the default case. */
341 switch (GET_CODE (x))
343 case CONST_INT:
344 case CONST_DOUBLE:
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;
358 case SUBREG:
359 if ((SUBREG_PROMOTED_VAR_P (x) || REG_POINTER (SUBREG_REG (x)))
360 && GET_MODE (SUBREG_REG (x)) == to_mode)
361 return SUBREG_REG (x);
362 break;
364 case LABEL_REF:
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;
368 break;
370 case SYMBOL_REF:
371 temp = shallow_copy_rtx (x);
372 PUT_MODE (temp, to_mode);
373 return temp;
374 break;
376 case CONST:
377 return gen_rtx_CONST (to_mode,
378 convert_memory_address (to_mode, XEXP (x, 0)));
379 break;
381 case PLUS:
382 case MULT:
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 or if one operand is a constant and we are
386 using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0).
387 We can always safely permute them if we are making the address
388 narrower. */
389 if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)
390 || (GET_CODE (x) == PLUS
391 && CONST_INT_P (XEXP (x, 1))
392 && (XEXP (x, 1) == convert_memory_address (to_mode, XEXP (x, 1))
393 || POINTERS_EXTEND_UNSIGNED < 0)))
394 return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
395 convert_memory_address (to_mode, XEXP (x, 0)),
396 XEXP (x, 1));
397 break;
399 default:
400 break;
403 return convert_modes (to_mode, from_mode,
404 x, POINTERS_EXTEND_UNSIGNED);
405 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
408 /* Return something equivalent to X but valid as a memory address
409 for something of mode MODE. When X is not itself valid, this
410 works by copying X or subexpressions of it into registers. */
413 memory_address (enum machine_mode mode, rtx x)
415 rtx oldx = x;
417 x = convert_memory_address (Pmode, x);
419 /* By passing constant addresses through registers
420 we get a chance to cse them. */
421 if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x))
422 x = force_reg (Pmode, x);
424 /* We get better cse by rejecting indirect addressing at this stage.
425 Let the combiner create indirect addresses where appropriate.
426 For now, generate the code so that the subexpressions useful to share
427 are visible. But not if cse won't be done! */
428 else
430 if (! cse_not_expected && !REG_P (x))
431 x = break_out_memory_refs (x);
433 /* At this point, any valid address is accepted. */
434 if (memory_address_p (mode, x))
435 goto done;
437 /* If it was valid before but breaking out memory refs invalidated it,
438 use it the old way. */
439 if (memory_address_p (mode, oldx))
441 x = oldx;
442 goto done;
445 /* Perform machine-dependent transformations on X
446 in certain cases. This is not necessary since the code
447 below can handle all possible cases, but machine-dependent
448 transformations can make better code. */
450 rtx orig_x = x;
451 x = targetm.legitimize_address (x, oldx, mode);
452 if (orig_x != x && memory_address_p (mode, x))
453 goto done;
456 /* PLUS and MULT can appear in special ways
457 as the result of attempts to make an address usable for indexing.
458 Usually they are dealt with by calling force_operand, below.
459 But a sum containing constant terms is special
460 if removing them makes the sum a valid address:
461 then we generate that address in a register
462 and index off of it. We do this because it often makes
463 shorter code, and because the addresses thus generated
464 in registers often become common subexpressions. */
465 if (GET_CODE (x) == PLUS)
467 rtx constant_term = const0_rtx;
468 rtx y = eliminate_constant_term (x, &constant_term);
469 if (constant_term == const0_rtx
470 || ! memory_address_p (mode, y))
471 x = force_operand (x, NULL_RTX);
472 else
474 y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term);
475 if (! memory_address_p (mode, y))
476 x = force_operand (x, NULL_RTX);
477 else
478 x = y;
482 else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS)
483 x = force_operand (x, NULL_RTX);
485 /* If we have a register that's an invalid address,
486 it must be a hard reg of the wrong class. Copy it to a pseudo. */
487 else if (REG_P (x))
488 x = copy_to_reg (x);
490 /* Last resort: copy the value to a register, since
491 the register is a valid address. */
492 else
493 x = force_reg (Pmode, x);
496 done:
498 gcc_assert (memory_address_p (mode, x));
499 /* If we didn't change the address, we are done. Otherwise, mark
500 a reg as a pointer if we have REG or REG + CONST_INT. */
501 if (oldx == x)
502 return x;
503 else if (REG_P (x))
504 mark_reg_pointer (x, BITS_PER_UNIT);
505 else if (GET_CODE (x) == PLUS
506 && REG_P (XEXP (x, 0))
507 && CONST_INT_P (XEXP (x, 1)))
508 mark_reg_pointer (XEXP (x, 0), BITS_PER_UNIT);
510 /* OLDX may have been the address on a temporary. Update the address
511 to indicate that X is now used. */
512 update_temp_slot_address (oldx, x);
514 return x;
517 /* Convert a mem ref into one with a valid memory address.
518 Pass through anything else unchanged. */
521 validize_mem (rtx ref)
523 if (!MEM_P (ref))
524 return ref;
525 ref = use_anchored_address (ref);
526 if (memory_address_p (GET_MODE (ref), XEXP (ref, 0)))
527 return ref;
529 /* Don't alter REF itself, since that is probably a stack slot. */
530 return replace_equiv_address (ref, XEXP (ref, 0));
533 /* If X is a memory reference to a member of an object block, try rewriting
534 it to use an anchor instead. Return the new memory reference on success
535 and the old one on failure. */
538 use_anchored_address (rtx x)
540 rtx base;
541 HOST_WIDE_INT offset;
543 if (!flag_section_anchors)
544 return x;
546 if (!MEM_P (x))
547 return x;
549 /* Split the address into a base and offset. */
550 base = XEXP (x, 0);
551 offset = 0;
552 if (GET_CODE (base) == CONST
553 && GET_CODE (XEXP (base, 0)) == PLUS
554 && CONST_INT_P (XEXP (XEXP (base, 0), 1)))
556 offset += INTVAL (XEXP (XEXP (base, 0), 1));
557 base = XEXP (XEXP (base, 0), 0);
560 /* Check whether BASE is suitable for anchors. */
561 if (GET_CODE (base) != SYMBOL_REF
562 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base)
563 || SYMBOL_REF_ANCHOR_P (base)
564 || SYMBOL_REF_BLOCK (base) == NULL
565 || !targetm.use_anchors_for_symbol_p (base))
566 return x;
568 /* Decide where BASE is going to be. */
569 place_block_symbol (base);
571 /* Get the anchor we need to use. */
572 offset += SYMBOL_REF_BLOCK_OFFSET (base);
573 base = get_section_anchor (SYMBOL_REF_BLOCK (base), offset,
574 SYMBOL_REF_TLS_MODEL (base));
576 /* Work out the offset from the anchor. */
577 offset -= SYMBOL_REF_BLOCK_OFFSET (base);
579 /* If we're going to run a CSE pass, force the anchor into a register.
580 We will then be able to reuse registers for several accesses, if the
581 target costs say that that's worthwhile. */
582 if (!cse_not_expected)
583 base = force_reg (GET_MODE (base), base);
585 return replace_equiv_address (x, plus_constant (base, offset));
588 /* Copy the value or contents of X to a new temp reg and return that reg. */
591 copy_to_reg (rtx x)
593 rtx temp = gen_reg_rtx (GET_MODE (x));
595 /* If not an operand, must be an address with PLUS and MULT so
596 do the computation. */
597 if (! general_operand (x, VOIDmode))
598 x = force_operand (x, temp);
600 if (x != temp)
601 emit_move_insn (temp, x);
603 return temp;
606 /* Like copy_to_reg but always give the new register mode Pmode
607 in case X is a constant. */
610 copy_addr_to_reg (rtx x)
612 return copy_to_mode_reg (Pmode, x);
615 /* Like copy_to_reg but always give the new register mode MODE
616 in case X is a constant. */
619 copy_to_mode_reg (enum machine_mode mode, rtx x)
621 rtx temp = gen_reg_rtx (mode);
623 /* If not an operand, must be an address with PLUS and MULT so
624 do the computation. */
625 if (! general_operand (x, VOIDmode))
626 x = force_operand (x, temp);
628 gcc_assert (GET_MODE (x) == mode || GET_MODE (x) == VOIDmode);
629 if (x != temp)
630 emit_move_insn (temp, x);
631 return temp;
634 /* Load X into a register if it is not already one.
635 Use mode MODE for the register.
636 X should be valid for mode MODE, but it may be a constant which
637 is valid for all integer modes; that's why caller must specify MODE.
639 The caller must not alter the value in the register we return,
640 since we mark it as a "constant" register. */
643 force_reg (enum machine_mode mode, rtx x)
645 rtx temp, insn, set;
647 if (REG_P (x))
648 return x;
650 if (general_operand (x, mode))
652 temp = gen_reg_rtx (mode);
653 insn = emit_move_insn (temp, x);
655 else
657 temp = force_operand (x, NULL_RTX);
658 if (REG_P (temp))
659 insn = get_last_insn ();
660 else
662 rtx temp2 = gen_reg_rtx (mode);
663 insn = emit_move_insn (temp2, temp);
664 temp = temp2;
668 /* Let optimizers know that TEMP's value never changes
669 and that X can be substituted for it. Don't get confused
670 if INSN set something else (such as a SUBREG of TEMP). */
671 if (CONSTANT_P (x)
672 && (set = single_set (insn)) != 0
673 && SET_DEST (set) == temp
674 && ! rtx_equal_p (x, SET_SRC (set)))
675 set_unique_reg_note (insn, REG_EQUAL, x);
677 /* Let optimizers know that TEMP is a pointer, and if so, the
678 known alignment of that pointer. */
680 unsigned align = 0;
681 if (GET_CODE (x) == SYMBOL_REF)
683 align = BITS_PER_UNIT;
684 if (SYMBOL_REF_DECL (x) && DECL_P (SYMBOL_REF_DECL (x)))
685 align = DECL_ALIGN (SYMBOL_REF_DECL (x));
687 else if (GET_CODE (x) == LABEL_REF)
688 align = BITS_PER_UNIT;
689 else if (GET_CODE (x) == CONST
690 && GET_CODE (XEXP (x, 0)) == PLUS
691 && GET_CODE (XEXP (XEXP (x, 0), 0)) == SYMBOL_REF
692 && CONST_INT_P (XEXP (XEXP (x, 0), 1)))
694 rtx s = XEXP (XEXP (x, 0), 0);
695 rtx c = XEXP (XEXP (x, 0), 1);
696 unsigned sa, ca;
698 sa = BITS_PER_UNIT;
699 if (SYMBOL_REF_DECL (s) && DECL_P (SYMBOL_REF_DECL (s)))
700 sa = DECL_ALIGN (SYMBOL_REF_DECL (s));
702 ca = exact_log2 (INTVAL (c) & -INTVAL (c)) * BITS_PER_UNIT;
704 align = MIN (sa, ca);
707 if (align || (MEM_P (x) && MEM_POINTER (x)))
708 mark_reg_pointer (temp, align);
711 return temp;
714 /* If X is a memory ref, copy its contents to a new temp reg and return
715 that reg. Otherwise, return X. */
718 force_not_mem (rtx x)
720 rtx temp;
722 if (!MEM_P (x) || GET_MODE (x) == BLKmode)
723 return x;
725 temp = gen_reg_rtx (GET_MODE (x));
727 if (MEM_POINTER (x))
728 REG_POINTER (temp) = 1;
730 emit_move_insn (temp, x);
731 return temp;
734 /* Copy X to TARGET (if it's nonzero and a reg)
735 or to a new temp reg and return that reg.
736 MODE is the mode to use for X in case it is a constant. */
739 copy_to_suggested_reg (rtx x, rtx target, enum machine_mode mode)
741 rtx temp;
743 if (target && REG_P (target))
744 temp = target;
745 else
746 temp = gen_reg_rtx (mode);
748 emit_move_insn (temp, x);
749 return temp;
752 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
753 PUNSIGNEDP points to the signedness of the type and may be adjusted
754 to show what signedness to use on extension operations.
756 FOR_RETURN is nonzero if the caller is promoting the return value
757 of FNDECL, else it is for promoting args. */
759 enum machine_mode
760 promote_function_mode (const_tree type, enum machine_mode mode, int *punsignedp,
761 const_tree funtype, int for_return)
763 switch (TREE_CODE (type))
765 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
766 case REAL_TYPE: case OFFSET_TYPE: case FIXED_POINT_TYPE:
767 case POINTER_TYPE: case REFERENCE_TYPE:
768 return targetm.calls.promote_function_mode (type, mode, punsignedp, funtype,
769 for_return);
771 default:
772 return mode;
775 /* Return the mode to use to store a scalar of TYPE and MODE.
776 PUNSIGNEDP points to the signedness of the type and may be adjusted
777 to show what signedness to use on extension operations. */
779 enum machine_mode
780 promote_mode (const_tree type ATTRIBUTE_UNUSED, enum machine_mode mode,
781 int *punsignedp ATTRIBUTE_UNUSED)
783 /* FIXME: this is the same logic that was there until GCC 4.4, but we
784 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
785 is not defined. The affected targets are M32C, S390, SPARC. */
786 #ifdef PROMOTE_MODE
787 const enum tree_code code = TREE_CODE (type);
788 int unsignedp = *punsignedp;
790 switch (code)
792 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
793 case REAL_TYPE: case OFFSET_TYPE: case FIXED_POINT_TYPE:
794 PROMOTE_MODE (mode, unsignedp, type);
795 *punsignedp = unsignedp;
796 return mode;
797 break;
799 #ifdef POINTERS_EXTEND_UNSIGNED
800 case REFERENCE_TYPE:
801 case POINTER_TYPE:
802 *punsignedp = POINTERS_EXTEND_UNSIGNED;
803 return Pmode;
804 break;
805 #endif
807 default:
808 return mode;
810 #else
811 return mode;
812 #endif
816 /* Use one of promote_mode or promote_function_mode to find the promoted
817 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
818 of DECL after promotion. */
820 enum machine_mode
821 promote_decl_mode (const_tree decl, int *punsignedp)
823 tree type = TREE_TYPE (decl);
824 int unsignedp = TYPE_UNSIGNED (type);
825 enum machine_mode mode = DECL_MODE (decl);
826 enum machine_mode pmode;
828 if (TREE_CODE (decl) == RESULT_DECL
829 || TREE_CODE (decl) == PARM_DECL)
830 pmode = promote_function_mode (type, mode, &unsignedp,
831 TREE_TYPE (current_function_decl), 2);
832 else
833 pmode = promote_mode (type, mode, &unsignedp);
835 if (punsignedp)
836 *punsignedp = unsignedp;
837 return pmode;
841 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
842 This pops when ADJUST is positive. ADJUST need not be constant. */
844 void
845 adjust_stack (rtx adjust)
847 rtx temp;
849 if (adjust == const0_rtx)
850 return;
852 /* We expect all variable sized adjustments to be multiple of
853 PREFERRED_STACK_BOUNDARY. */
854 if (CONST_INT_P (adjust))
855 stack_pointer_delta -= INTVAL (adjust);
857 temp = expand_binop (Pmode,
858 #ifdef STACK_GROWS_DOWNWARD
859 add_optab,
860 #else
861 sub_optab,
862 #endif
863 stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
864 OPTAB_LIB_WIDEN);
866 if (temp != stack_pointer_rtx)
867 emit_move_insn (stack_pointer_rtx, temp);
870 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
871 This pushes when ADJUST is positive. ADJUST need not be constant. */
873 void
874 anti_adjust_stack (rtx adjust)
876 rtx temp;
878 if (adjust == const0_rtx)
879 return;
881 /* We expect all variable sized adjustments to be multiple of
882 PREFERRED_STACK_BOUNDARY. */
883 if (CONST_INT_P (adjust))
884 stack_pointer_delta += INTVAL (adjust);
886 temp = expand_binop (Pmode,
887 #ifdef STACK_GROWS_DOWNWARD
888 sub_optab,
889 #else
890 add_optab,
891 #endif
892 stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
893 OPTAB_LIB_WIDEN);
895 if (temp != stack_pointer_rtx)
896 emit_move_insn (stack_pointer_rtx, temp);
899 /* Round the size of a block to be pushed up to the boundary required
900 by this machine. SIZE is the desired size, which need not be constant. */
902 static rtx
903 round_push (rtx size)
905 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
907 if (align == 1)
908 return size;
910 if (CONST_INT_P (size))
912 HOST_WIDE_INT new_size = (INTVAL (size) + align - 1) / align * align;
914 if (INTVAL (size) != new_size)
915 size = GEN_INT (new_size);
917 else
919 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
920 but we know it can't. So add ourselves and then do
921 TRUNC_DIV_EXPR. */
922 size = expand_binop (Pmode, add_optab, size, GEN_INT (align - 1),
923 NULL_RTX, 1, OPTAB_LIB_WIDEN);
924 size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, GEN_INT (align),
925 NULL_RTX, 1);
926 size = expand_mult (Pmode, size, GEN_INT (align), NULL_RTX, 1);
929 return size;
932 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
933 to a previously-created save area. If no save area has been allocated,
934 this function will allocate one. If a save area is specified, it
935 must be of the proper mode.
937 The insns are emitted after insn AFTER, if nonzero, otherwise the insns
938 are emitted at the current position. */
940 void
941 emit_stack_save (enum save_level save_level, rtx *psave, rtx after)
943 rtx sa = *psave;
944 /* The default is that we use a move insn and save in a Pmode object. */
945 rtx (*fcn) (rtx, rtx) = gen_move_insn;
946 enum machine_mode mode = STACK_SAVEAREA_MODE (save_level);
948 /* See if this machine has anything special to do for this kind of save. */
949 switch (save_level)
951 #ifdef HAVE_save_stack_block
952 case SAVE_BLOCK:
953 if (HAVE_save_stack_block)
954 fcn = gen_save_stack_block;
955 break;
956 #endif
957 #ifdef HAVE_save_stack_function
958 case SAVE_FUNCTION:
959 if (HAVE_save_stack_function)
960 fcn = gen_save_stack_function;
961 break;
962 #endif
963 #ifdef HAVE_save_stack_nonlocal
964 case SAVE_NONLOCAL:
965 if (HAVE_save_stack_nonlocal)
966 fcn = gen_save_stack_nonlocal;
967 break;
968 #endif
969 default:
970 break;
973 /* If there is no save area and we have to allocate one, do so. Otherwise
974 verify the save area is the proper mode. */
976 if (sa == 0)
978 if (mode != VOIDmode)
980 if (save_level == SAVE_NONLOCAL)
981 *psave = sa = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
982 else
983 *psave = sa = gen_reg_rtx (mode);
987 if (after)
989 rtx seq;
991 start_sequence ();
992 do_pending_stack_adjust ();
993 /* We must validize inside the sequence, to ensure that any instructions
994 created by the validize call also get moved to the right place. */
995 if (sa != 0)
996 sa = validize_mem (sa);
997 emit_insn (fcn (sa, stack_pointer_rtx));
998 seq = get_insns ();
999 end_sequence ();
1000 emit_insn_after (seq, after);
1002 else
1004 do_pending_stack_adjust ();
1005 if (sa != 0)
1006 sa = validize_mem (sa);
1007 emit_insn (fcn (sa, stack_pointer_rtx));
1011 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1012 area made by emit_stack_save. If it is zero, we have nothing to do.
1014 Put any emitted insns after insn AFTER, if nonzero, otherwise at
1015 current position. */
1017 void
1018 emit_stack_restore (enum save_level save_level, rtx sa, rtx after)
1020 /* The default is that we use a move insn. */
1021 rtx (*fcn) (rtx, rtx) = gen_move_insn;
1023 /* See if this machine has anything special to do for this kind of save. */
1024 switch (save_level)
1026 #ifdef HAVE_restore_stack_block
1027 case SAVE_BLOCK:
1028 if (HAVE_restore_stack_block)
1029 fcn = gen_restore_stack_block;
1030 break;
1031 #endif
1032 #ifdef HAVE_restore_stack_function
1033 case SAVE_FUNCTION:
1034 if (HAVE_restore_stack_function)
1035 fcn = gen_restore_stack_function;
1036 break;
1037 #endif
1038 #ifdef HAVE_restore_stack_nonlocal
1039 case SAVE_NONLOCAL:
1040 if (HAVE_restore_stack_nonlocal)
1041 fcn = gen_restore_stack_nonlocal;
1042 break;
1043 #endif
1044 default:
1045 break;
1048 if (sa != 0)
1050 sa = validize_mem (sa);
1051 /* These clobbers prevent the scheduler from moving
1052 references to variable arrays below the code
1053 that deletes (pops) the arrays. */
1054 emit_clobber (gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode)));
1055 emit_clobber (gen_rtx_MEM (BLKmode, stack_pointer_rtx));
1058 discard_pending_stack_adjust ();
1060 if (after)
1062 rtx seq;
1064 start_sequence ();
1065 emit_insn (fcn (stack_pointer_rtx, sa));
1066 seq = get_insns ();
1067 end_sequence ();
1068 emit_insn_after (seq, after);
1070 else
1071 emit_insn (fcn (stack_pointer_rtx, sa));
1074 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1075 function. This function should be called whenever we allocate or
1076 deallocate dynamic stack space. */
1078 void
1079 update_nonlocal_goto_save_area (void)
1081 tree t_save;
1082 rtx r_save;
1084 /* The nonlocal_goto_save_area object is an array of N pointers. The
1085 first one is used for the frame pointer save; the rest are sized by
1086 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1087 of the stack save area slots. */
1088 t_save = build4 (ARRAY_REF, ptr_type_node, cfun->nonlocal_goto_save_area,
1089 integer_one_node, NULL_TREE, NULL_TREE);
1090 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
1092 emit_stack_save (SAVE_NONLOCAL, &r_save, NULL_RTX);
1095 /* Return an rtx representing the address of an area of memory dynamically
1096 pushed on the stack. This region of memory is always aligned to
1097 a multiple of BIGGEST_ALIGNMENT.
1099 Any required stack pointer alignment is preserved.
1101 SIZE is an rtx representing the size of the area.
1102 TARGET is a place in which the address can be placed.
1104 KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */
1107 allocate_dynamic_stack_space (rtx size, rtx target, int known_align)
1109 /* If we're asking for zero bytes, it doesn't matter what we point
1110 to since we can't dereference it. But return a reasonable
1111 address anyway. */
1112 if (size == const0_rtx)
1113 return virtual_stack_dynamic_rtx;
1115 /* Otherwise, show we're calling alloca or equivalent. */
1116 cfun->calls_alloca = 1;
1118 /* Ensure the size is in the proper mode. */
1119 if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
1120 size = convert_to_mode (Pmode, size, 1);
1122 /* We can't attempt to minimize alignment necessary, because we don't
1123 know the final value of preferred_stack_boundary yet while executing
1124 this code. */
1125 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
1127 /* We will need to ensure that the address we return is aligned to
1128 BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
1129 always know its final value at this point in the compilation (it
1130 might depend on the size of the outgoing parameter lists, for
1131 example), so we must align the value to be returned in that case.
1132 (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
1133 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1134 We must also do an alignment operation on the returned value if
1135 the stack pointer alignment is less strict that BIGGEST_ALIGNMENT.
1137 If we have to align, we must leave space in SIZE for the hole
1138 that might result from the alignment operation. */
1140 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
1141 #define MUST_ALIGN 1
1142 #else
1143 #define MUST_ALIGN (PREFERRED_STACK_BOUNDARY < BIGGEST_ALIGNMENT)
1144 #endif
1146 if (MUST_ALIGN)
1147 size
1148 = force_operand (plus_constant (size,
1149 BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
1150 NULL_RTX);
1152 #ifdef SETJMP_VIA_SAVE_AREA
1153 /* If setjmp restores regs from a save area in the stack frame,
1154 avoid clobbering the reg save area. Note that the offset of
1155 virtual_incoming_args_rtx includes the preallocated stack args space.
1156 It would be no problem to clobber that, but it's on the wrong side
1157 of the old save area.
1159 What used to happen is that, since we did not know for sure
1160 whether setjmp() was invoked until after RTL generation, we
1161 would use reg notes to store the "optimized" size and fix things
1162 up later. These days we know this information before we ever
1163 start building RTL so the reg notes are unnecessary. */
1164 if (!cfun->calls_setjmp)
1166 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
1168 /* ??? Code below assumes that the save area needs maximal
1169 alignment. This constraint may be too strong. */
1170 gcc_assert (PREFERRED_STACK_BOUNDARY == BIGGEST_ALIGNMENT);
1172 if (CONST_INT_P (size))
1174 HOST_WIDE_INT new_size = INTVAL (size) / align * align;
1176 if (INTVAL (size) != new_size)
1177 size = GEN_INT (new_size);
1179 else
1181 /* Since we know overflow is not possible, we avoid using
1182 CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */
1183 size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size,
1184 GEN_INT (align), NULL_RTX, 1);
1185 size = expand_mult (Pmode, size,
1186 GEN_INT (align), NULL_RTX, 1);
1189 else
1191 rtx dynamic_offset
1192 = expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx,
1193 stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN);
1195 size = expand_binop (Pmode, add_optab, size, dynamic_offset,
1196 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1198 #endif /* SETJMP_VIA_SAVE_AREA */
1200 /* Round the size to a multiple of the required stack alignment.
1201 Since the stack if presumed to be rounded before this allocation,
1202 this will maintain the required alignment.
1204 If the stack grows downward, we could save an insn by subtracting
1205 SIZE from the stack pointer and then aligning the stack pointer.
1206 The problem with this is that the stack pointer may be unaligned
1207 between the execution of the subtraction and alignment insns and
1208 some machines do not allow this. Even on those that do, some
1209 signal handlers malfunction if a signal should occur between those
1210 insns. Since this is an extremely rare event, we have no reliable
1211 way of knowing which systems have this problem. So we avoid even
1212 momentarily mis-aligning the stack. */
1214 /* If we added a variable amount to SIZE,
1215 we can no longer assume it is aligned. */
1216 #if !defined (SETJMP_VIA_SAVE_AREA)
1217 if (MUST_ALIGN || known_align % PREFERRED_STACK_BOUNDARY != 0)
1218 #endif
1219 size = round_push (size);
1221 do_pending_stack_adjust ();
1223 /* We ought to be called always on the toplevel and stack ought to be aligned
1224 properly. */
1225 gcc_assert (!(stack_pointer_delta
1226 % (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)));
1228 /* If needed, check that we have the required amount of stack.
1229 Take into account what has already been checked. */
1230 if (flag_stack_check == GENERIC_STACK_CHECK)
1231 probe_stack_range (STACK_OLD_CHECK_PROTECT + STACK_CHECK_MAX_FRAME_SIZE,
1232 size);
1233 else if (flag_stack_check == STATIC_BUILTIN_STACK_CHECK)
1234 probe_stack_range (STACK_CHECK_PROTECT, size);
1236 /* Don't use a TARGET that isn't a pseudo or is the wrong mode. */
1237 if (target == 0 || !REG_P (target)
1238 || REGNO (target) < FIRST_PSEUDO_REGISTER
1239 || GET_MODE (target) != Pmode)
1240 target = gen_reg_rtx (Pmode);
1242 mark_reg_pointer (target, known_align);
1244 /* Perform the required allocation from the stack. Some systems do
1245 this differently than simply incrementing/decrementing from the
1246 stack pointer, such as acquiring the space by calling malloc(). */
1247 #ifdef HAVE_allocate_stack
1248 if (HAVE_allocate_stack)
1250 enum machine_mode mode = STACK_SIZE_MODE;
1251 insn_operand_predicate_fn pred;
1253 /* We don't have to check against the predicate for operand 0 since
1254 TARGET is known to be a pseudo of the proper mode, which must
1255 be valid for the operand. For operand 1, convert to the
1256 proper mode and validate. */
1257 if (mode == VOIDmode)
1258 mode = insn_data[(int) CODE_FOR_allocate_stack].operand[1].mode;
1260 pred = insn_data[(int) CODE_FOR_allocate_stack].operand[1].predicate;
1261 if (pred && ! ((*pred) (size, mode)))
1262 size = copy_to_mode_reg (mode, convert_to_mode (mode, size, 1));
1264 emit_insn (gen_allocate_stack (target, size));
1266 else
1267 #endif
1269 #ifndef STACK_GROWS_DOWNWARD
1270 emit_move_insn (target, virtual_stack_dynamic_rtx);
1271 #endif
1273 /* Check stack bounds if necessary. */
1274 if (crtl->limit_stack)
1276 rtx available;
1277 rtx space_available = gen_label_rtx ();
1278 #ifdef STACK_GROWS_DOWNWARD
1279 available = expand_binop (Pmode, sub_optab,
1280 stack_pointer_rtx, stack_limit_rtx,
1281 NULL_RTX, 1, OPTAB_WIDEN);
1282 #else
1283 available = expand_binop (Pmode, sub_optab,
1284 stack_limit_rtx, stack_pointer_rtx,
1285 NULL_RTX, 1, OPTAB_WIDEN);
1286 #endif
1287 emit_cmp_and_jump_insns (available, size, GEU, NULL_RTX, Pmode, 1,
1288 space_available);
1289 #ifdef HAVE_trap
1290 if (HAVE_trap)
1291 emit_insn (gen_trap ());
1292 else
1293 #endif
1294 error ("stack limits not supported on this target");
1295 emit_barrier ();
1296 emit_label (space_available);
1299 anti_adjust_stack (size);
1301 #ifdef STACK_GROWS_DOWNWARD
1302 emit_move_insn (target, virtual_stack_dynamic_rtx);
1303 #endif
1306 if (MUST_ALIGN)
1308 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1309 but we know it can't. So add ourselves and then do
1310 TRUNC_DIV_EXPR. */
1311 target = expand_binop (Pmode, add_optab, target,
1312 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
1313 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1314 target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target,
1315 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
1316 NULL_RTX, 1);
1317 target = expand_mult (Pmode, target,
1318 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
1319 NULL_RTX, 1);
1322 /* Record the new stack level for nonlocal gotos. */
1323 if (cfun->nonlocal_goto_save_area != 0)
1324 update_nonlocal_goto_save_area ();
1326 return target;
1329 /* A front end may want to override GCC's stack checking by providing a
1330 run-time routine to call to check the stack, so provide a mechanism for
1331 calling that routine. */
1333 static GTY(()) rtx stack_check_libfunc;
1335 void
1336 set_stack_check_libfunc (rtx libfunc)
1338 stack_check_libfunc = libfunc;
1341 /* Emit one stack probe at ADDRESS, an address within the stack. */
1343 static void
1344 emit_stack_probe (rtx address)
1346 rtx memref = gen_rtx_MEM (word_mode, address);
1348 MEM_VOLATILE_P (memref) = 1;
1350 if (STACK_CHECK_PROBE_LOAD)
1351 emit_move_insn (gen_reg_rtx (word_mode), memref);
1352 else
1353 emit_move_insn (memref, const0_rtx);
1356 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1357 FIRST is a constant and size is a Pmode RTX. These are offsets from the
1358 current stack pointer. STACK_GROWS_DOWNWARD says whether to add or
1359 subtract from the stack. If SIZE is constant, this is done
1360 with a fixed number of probes. Otherwise, we must make a loop. */
1362 #ifdef STACK_GROWS_DOWNWARD
1363 #define STACK_GROW_OP MINUS
1364 #else
1365 #define STACK_GROW_OP PLUS
1366 #endif
1368 void
1369 probe_stack_range (HOST_WIDE_INT first, rtx size)
1371 /* First ensure SIZE is Pmode. */
1372 if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
1373 size = convert_to_mode (Pmode, size, 1);
1375 /* Next see if the front end has set up a function for us to call to
1376 check the stack. */
1377 if (stack_check_libfunc != 0)
1379 rtx addr = memory_address (QImode,
1380 gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1381 stack_pointer_rtx,
1382 plus_constant (size, first)));
1384 addr = convert_memory_address (ptr_mode, addr);
1385 emit_library_call (stack_check_libfunc, LCT_NORMAL, VOIDmode, 1, addr,
1386 ptr_mode);
1389 /* Next see if we have an insn to check the stack. Use it if so. */
1390 #ifdef HAVE_check_stack
1391 else if (HAVE_check_stack)
1393 insn_operand_predicate_fn pred;
1394 rtx last_addr
1395 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1396 stack_pointer_rtx,
1397 plus_constant (size, first)),
1398 NULL_RTX);
1400 pred = insn_data[(int) CODE_FOR_check_stack].operand[0].predicate;
1401 if (pred && ! ((*pred) (last_addr, Pmode)))
1402 last_addr = copy_to_mode_reg (Pmode, last_addr);
1404 emit_insn (gen_check_stack (last_addr));
1406 #endif
1408 /* If we have to generate explicit probes, see if we have a constant
1409 small number of them to generate. If so, that's the easy case. */
1410 else if (CONST_INT_P (size)
1411 && INTVAL (size) < 10 * STACK_CHECK_PROBE_INTERVAL)
1413 HOST_WIDE_INT offset;
1415 /* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL
1416 for values of N from 1 until it exceeds LAST. If only one
1417 probe is needed, this will not generate any code. Then probe
1418 at LAST. */
1419 for (offset = first + STACK_CHECK_PROBE_INTERVAL;
1420 offset < INTVAL (size);
1421 offset = offset + STACK_CHECK_PROBE_INTERVAL)
1422 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1423 stack_pointer_rtx,
1424 GEN_INT (offset)));
1426 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1427 stack_pointer_rtx,
1428 plus_constant (size, first)));
1431 /* In the variable case, do the same as above, but in a loop. We emit loop
1432 notes so that loop optimization can be done. */
1433 else
1435 rtx test_addr
1436 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1437 stack_pointer_rtx,
1438 GEN_INT (first + STACK_CHECK_PROBE_INTERVAL)),
1439 NULL_RTX);
1440 rtx last_addr
1441 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1442 stack_pointer_rtx,
1443 plus_constant (size, first)),
1444 NULL_RTX);
1445 rtx incr = GEN_INT (STACK_CHECK_PROBE_INTERVAL);
1446 rtx loop_lab = gen_label_rtx ();
1447 rtx test_lab = gen_label_rtx ();
1448 rtx end_lab = gen_label_rtx ();
1449 rtx temp;
1451 if (!REG_P (test_addr)
1452 || REGNO (test_addr) < FIRST_PSEUDO_REGISTER)
1453 test_addr = force_reg (Pmode, test_addr);
1455 emit_jump (test_lab);
1457 emit_label (loop_lab);
1458 emit_stack_probe (test_addr);
1460 #ifdef STACK_GROWS_DOWNWARD
1461 #define CMP_OPCODE GTU
1462 temp = expand_binop (Pmode, sub_optab, test_addr, incr, test_addr,
1463 1, OPTAB_WIDEN);
1464 #else
1465 #define CMP_OPCODE LTU
1466 temp = expand_binop (Pmode, add_optab, test_addr, incr, test_addr,
1467 1, OPTAB_WIDEN);
1468 #endif
1470 gcc_assert (temp == test_addr);
1472 emit_label (test_lab);
1473 emit_cmp_and_jump_insns (test_addr, last_addr, CMP_OPCODE,
1474 NULL_RTX, Pmode, 1, loop_lab);
1475 emit_jump (end_lab);
1476 emit_label (end_lab);
1478 emit_stack_probe (last_addr);
1482 /* Return an rtx representing the register or memory location
1483 in which a scalar value of data type VALTYPE
1484 was returned by a function call to function FUNC.
1485 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1486 function is known, otherwise 0.
1487 OUTGOING is 1 if on a machine with register windows this function
1488 should return the register in which the function will put its result
1489 and 0 otherwise. */
1492 hard_function_value (const_tree valtype, const_tree func, const_tree fntype,
1493 int outgoing ATTRIBUTE_UNUSED)
1495 rtx val;
1497 val = targetm.calls.function_value (valtype, func ? func : fntype, outgoing);
1499 if (REG_P (val)
1500 && GET_MODE (val) == BLKmode)
1502 unsigned HOST_WIDE_INT bytes = int_size_in_bytes (valtype);
1503 enum machine_mode tmpmode;
1505 /* int_size_in_bytes can return -1. We don't need a check here
1506 since the value of bytes will then be large enough that no
1507 mode will match anyway. */
1509 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
1510 tmpmode != VOIDmode;
1511 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
1513 /* Have we found a large enough mode? */
1514 if (GET_MODE_SIZE (tmpmode) >= bytes)
1515 break;
1518 /* No suitable mode found. */
1519 gcc_assert (tmpmode != VOIDmode);
1521 PUT_MODE (val, tmpmode);
1523 return val;
1526 /* Return an rtx representing the register or memory location
1527 in which a scalar value of mode MODE was returned by a library call. */
1530 hard_libcall_value (enum machine_mode mode, rtx fun)
1532 return targetm.calls.libcall_value (mode, fun);
1535 /* Look up the tree code for a given rtx code
1536 to provide the arithmetic operation for REAL_ARITHMETIC.
1537 The function returns an int because the caller may not know
1538 what `enum tree_code' means. */
1541 rtx_to_tree_code (enum rtx_code code)
1543 enum tree_code tcode;
1545 switch (code)
1547 case PLUS:
1548 tcode = PLUS_EXPR;
1549 break;
1550 case MINUS:
1551 tcode = MINUS_EXPR;
1552 break;
1553 case MULT:
1554 tcode = MULT_EXPR;
1555 break;
1556 case DIV:
1557 tcode = RDIV_EXPR;
1558 break;
1559 case SMIN:
1560 tcode = MIN_EXPR;
1561 break;
1562 case SMAX:
1563 tcode = MAX_EXPR;
1564 break;
1565 default:
1566 tcode = LAST_AND_UNUSED_TREE_CODE;
1567 break;
1569 return ((int) tcode);
1572 #include "gt-explow.h"