1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987, 91, 94-97, 1998 Free Software Foundation, Inc.
4 This file is part of GNU CC.
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)
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.
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. */
28 #include "hard-reg-set.h"
29 #include "insn-config.h"
31 #include "insn-flags.h"
32 #include "insn-codes.h"
34 #if !defined PREFERRED_STACK_BOUNDARY && defined STACK_BOUNDARY
35 #define PREFERRED_STACK_BOUNDARY STACK_BOUNDARY
38 static rtx break_out_memory_refs PROTO((rtx));
39 static void emit_stack_probe PROTO((rtx));
40 /* Return an rtx for the sum of X and the integer C.
42 This function should be used via the `plus_constant' macro. */
45 plus_constant_wide (x, c)
47 register HOST_WIDE_INT c;
49 register RTX_CODE code;
50 register enum machine_mode mode;
64 return GEN_INT (INTVAL (x) + c);
68 HOST_WIDE_INT l1 = CONST_DOUBLE_LOW (x);
69 HOST_WIDE_INT h1 = CONST_DOUBLE_HIGH (x);
71 HOST_WIDE_INT h2 = c < 0 ? ~0 : 0;
74 add_double (l1, h1, l2, h2, &lv, &hv);
76 return immed_double_const (lv, hv, VOIDmode);
80 /* If this is a reference to the constant pool, try replacing it with
81 a reference to a new constant. If the resulting address isn't
82 valid, don't return it because we have no way to validize it. */
83 if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF
84 && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)))
86 /* Any rtl we create here must go in a saveable obstack, since
87 we might have been called from within combine. */
88 push_obstacks_nochange ();
89 rtl_in_saveable_obstack ();
91 = force_const_mem (GET_MODE (x),
92 plus_constant (get_pool_constant (XEXP (x, 0)),
95 if (memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
101 /* If adding to something entirely constant, set a flag
102 so that we can add a CONST around the result. */
113 /* The interesting case is adding the integer to a sum.
114 Look for constant term in the sum and combine
115 with C. For an integer constant term, we make a combined
116 integer. For a constant term that is not an explicit integer,
117 we cannot really combine, but group them together anyway.
119 Use a recursive call in case the remaining operand is something
120 that we handle specially, such as a SYMBOL_REF. */
122 if (GET_CODE (XEXP (x, 1)) == CONST_INT)
123 return plus_constant (XEXP (x, 0), c + INTVAL (XEXP (x, 1)));
124 else if (CONSTANT_P (XEXP (x, 0)))
125 return gen_rtx_PLUS (mode,
126 plus_constant (XEXP (x, 0), c),
128 else if (CONSTANT_P (XEXP (x, 1)))
129 return gen_rtx_PLUS (mode,
131 plus_constant (XEXP (x, 1), c));
139 x = gen_rtx_PLUS (mode, x, GEN_INT (c));
141 if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
143 else if (all_constant)
144 return gen_rtx_CONST (mode, x);
149 /* This is the same as `plus_constant', except that it handles LO_SUM.
151 This function should be used via the `plus_constant_for_output' macro. */
154 plus_constant_for_output_wide (x, c)
156 register HOST_WIDE_INT c;
158 register enum machine_mode mode = GET_MODE (x);
160 if (GET_CODE (x) == LO_SUM)
161 return gen_rtx_LO_SUM (mode, XEXP (x, 0),
162 plus_constant_for_output (XEXP (x, 1), c));
165 return plus_constant (x, c);
168 /* If X is a sum, return a new sum like X but lacking any constant terms.
169 Add all the removed constant terms into *CONSTPTR.
170 X itself is not altered. The result != X if and only if
171 it is not isomorphic to X. */
174 eliminate_constant_term (x, constptr)
181 if (GET_CODE (x) != PLUS)
184 /* First handle constants appearing at this level explicitly. */
185 if (GET_CODE (XEXP (x, 1)) == CONST_INT
186 && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr,
188 && GET_CODE (tem) == CONST_INT)
191 return eliminate_constant_term (XEXP (x, 0), constptr);
195 x0 = eliminate_constant_term (XEXP (x, 0), &tem);
196 x1 = eliminate_constant_term (XEXP (x, 1), &tem);
197 if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0))
198 && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x),
200 && GET_CODE (tem) == CONST_INT)
203 return gen_rtx_PLUS (GET_MODE (x), x0, x1);
209 /* Returns the insn that next references REG after INSN, or 0
210 if REG is clobbered before next referenced or we cannot find
211 an insn that references REG in a straight-line piece of code. */
214 find_next_ref (reg, insn)
220 for (insn = NEXT_INSN (insn); insn; insn = next)
222 next = NEXT_INSN (insn);
223 if (GET_CODE (insn) == NOTE)
225 if (GET_CODE (insn) == CODE_LABEL
226 || GET_CODE (insn) == BARRIER)
228 if (GET_CODE (insn) == INSN
229 || GET_CODE (insn) == JUMP_INSN
230 || GET_CODE (insn) == CALL_INSN)
232 if (reg_set_p (reg, insn))
234 if (reg_mentioned_p (reg, PATTERN (insn)))
236 if (GET_CODE (insn) == JUMP_INSN)
238 if (simplejump_p (insn))
239 next = JUMP_LABEL (insn);
243 if (GET_CODE (insn) == CALL_INSN
244 && REGNO (reg) < FIRST_PSEUDO_REGISTER
245 && call_used_regs[REGNO (reg)])
254 /* Return an rtx for the size in bytes of the value of EXP. */
260 tree size = size_in_bytes (TREE_TYPE (exp));
262 if (TREE_CODE (size) != INTEGER_CST
263 && contains_placeholder_p (size))
264 size = build (WITH_RECORD_EXPR, sizetype, size, exp);
266 return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype),
267 EXPAND_MEMORY_USE_BAD);
270 /* Return a copy of X in which all memory references
271 and all constants that involve symbol refs
272 have been replaced with new temporary registers.
273 Also emit code to load the memory locations and constants
274 into those registers.
276 If X contains no such constants or memory references,
277 X itself (not a copy) is returned.
279 If a constant is found in the address that is not a legitimate constant
280 in an insn, it is left alone in the hope that it might be valid in the
283 X may contain no arithmetic except addition, subtraction and multiplication.
284 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
287 break_out_memory_refs (x)
290 if (GET_CODE (x) == MEM
291 || (CONSTANT_P (x) && CONSTANT_ADDRESS_P (x)
292 && GET_MODE (x) != VOIDmode))
293 x = force_reg (GET_MODE (x), x);
294 else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
295 || GET_CODE (x) == MULT)
297 register rtx op0 = break_out_memory_refs (XEXP (x, 0));
298 register rtx op1 = break_out_memory_refs (XEXP (x, 1));
300 if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
301 x = gen_rtx_fmt_ee (GET_CODE (x), Pmode, op0, op1);
307 #ifdef POINTERS_EXTEND_UNSIGNED
309 /* Given X, a memory address in ptr_mode, convert it to an address
310 in Pmode, or vice versa (TO_MODE says which way). We take advantage of
311 the fact that pointers are not allowed to overflow by commuting arithmetic
312 operations over conversions so that address arithmetic insns can be
316 convert_memory_address (to_mode, x)
317 enum machine_mode to_mode;
320 enum machine_mode from_mode = to_mode == ptr_mode ? Pmode : ptr_mode;
323 /* Here we handle some special cases. If none of them apply, fall through
324 to the default case. */
325 switch (GET_CODE (x))
332 temp = gen_rtx_LABEL_REF (to_mode, XEXP (x, 0));
333 LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x);
337 temp = gen_rtx_SYMBOL_REF (to_mode, XSTR (x, 0));
338 SYMBOL_REF_FLAG (temp) = SYMBOL_REF_FLAG (x);
339 CONSTANT_POOL_ADDRESS_P (temp) = CONSTANT_POOL_ADDRESS_P (x);
343 return gen_rtx_CONST (to_mode,
344 convert_memory_address (to_mode, XEXP (x, 0)));
348 /* For addition the second operand is a small constant, we can safely
349 permute the conversion and addition operation. We can always safely
350 permute them if we are making the address narrower. In addition,
351 always permute the operations if this is a constant. */
352 if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)
353 || (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == CONST_INT
354 && (INTVAL (XEXP (x, 1)) + 20000 < 40000
355 || CONSTANT_P (XEXP (x, 0)))))
356 return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
357 convert_memory_address (to_mode, XEXP (x, 0)),
358 convert_memory_address (to_mode, XEXP (x, 1)));
365 return convert_modes (to_mode, from_mode,
366 x, POINTERS_EXTEND_UNSIGNED);
370 /* Given a memory address or facsimile X, construct a new address,
371 currently equivalent, that is stable: future stores won't change it.
373 X must be composed of constants, register and memory references
374 combined with addition, subtraction and multiplication:
375 in other words, just what you can get from expand_expr if sum_ok is 1.
377 Works by making copies of all regs and memory locations used
378 by X and combining them the same way X does.
379 You could also stabilize the reference to this address
380 by copying the address to a register with copy_to_reg;
381 but then you wouldn't get indexed addressing in the reference. */
387 if (GET_CODE (x) == REG)
389 if (REGNO (x) != FRAME_POINTER_REGNUM
390 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
391 && REGNO (x) != HARD_FRAME_POINTER_REGNUM
396 else if (GET_CODE (x) == MEM)
398 else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
399 || GET_CODE (x) == MULT)
401 register rtx op0 = copy_all_regs (XEXP (x, 0));
402 register rtx op1 = copy_all_regs (XEXP (x, 1));
403 if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
404 x = gen_rtx_fmt_ee (GET_CODE (x), Pmode, op0, op1);
409 /* Return something equivalent to X but valid as a memory address
410 for something of mode MODE. When X is not itself valid, this
411 works by copying X or subexpressions of it into registers. */
414 memory_address (mode, x)
415 enum machine_mode mode;
418 register rtx oldx = x;
420 if (GET_CODE (x) == ADDRESSOF)
423 #ifdef POINTERS_EXTEND_UNSIGNED
424 if (GET_MODE (x) == ptr_mode)
425 x = convert_memory_address (Pmode, x);
428 /* By passing constant addresses thru registers
429 we get a chance to cse them. */
430 if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x))
431 x = force_reg (Pmode, x);
433 /* Accept a QUEUED that refers to a REG
434 even though that isn't a valid address.
435 On attempting to put this in an insn we will call protect_from_queue
436 which will turn it into a REG, which is valid. */
437 else if (GET_CODE (x) == QUEUED
438 && GET_CODE (QUEUED_VAR (x)) == REG)
441 /* We get better cse by rejecting indirect addressing at this stage.
442 Let the combiner create indirect addresses where appropriate.
443 For now, generate the code so that the subexpressions useful to share
444 are visible. But not if cse won't be done! */
447 if (! cse_not_expected && GET_CODE (x) != REG)
448 x = break_out_memory_refs (x);
450 /* At this point, any valid address is accepted. */
451 GO_IF_LEGITIMATE_ADDRESS (mode, x, win);
453 /* If it was valid before but breaking out memory refs invalidated it,
454 use it the old way. */
455 if (memory_address_p (mode, oldx))
458 /* Perform machine-dependent transformations on X
459 in certain cases. This is not necessary since the code
460 below can handle all possible cases, but machine-dependent
461 transformations can make better code. */
462 LEGITIMIZE_ADDRESS (x, oldx, mode, win);
464 /* PLUS and MULT can appear in special ways
465 as the result of attempts to make an address usable for indexing.
466 Usually they are dealt with by calling force_operand, below.
467 But a sum containing constant terms is special
468 if removing them makes the sum a valid address:
469 then we generate that address in a register
470 and index off of it. We do this because it often makes
471 shorter code, and because the addresses thus generated
472 in registers often become common subexpressions. */
473 if (GET_CODE (x) == PLUS)
475 rtx constant_term = const0_rtx;
476 rtx y = eliminate_constant_term (x, &constant_term);
477 if (constant_term == const0_rtx
478 || ! memory_address_p (mode, y))
479 x = force_operand (x, NULL_RTX);
482 y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term);
483 if (! memory_address_p (mode, y))
484 x = force_operand (x, NULL_RTX);
490 else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS)
491 x = force_operand (x, NULL_RTX);
493 /* If we have a register that's an invalid address,
494 it must be a hard reg of the wrong class. Copy it to a pseudo. */
495 else if (GET_CODE (x) == REG)
498 /* Last resort: copy the value to a register, since
499 the register is a valid address. */
501 x = force_reg (Pmode, x);
508 if (flag_force_addr && ! cse_not_expected && GET_CODE (x) != REG
509 /* Don't copy an addr via a reg if it is one of our stack slots. */
510 && ! (GET_CODE (x) == PLUS
511 && (XEXP (x, 0) == virtual_stack_vars_rtx
512 || XEXP (x, 0) == virtual_incoming_args_rtx)))
514 if (general_operand (x, Pmode))
515 x = force_reg (Pmode, x);
517 x = force_operand (x, NULL_RTX);
523 /* If we didn't change the address, we are done. Otherwise, mark
524 a reg as a pointer if we have REG or REG + CONST_INT. */
527 else if (GET_CODE (x) == REG)
528 mark_reg_pointer (x, 1);
529 else if (GET_CODE (x) == PLUS
530 && GET_CODE (XEXP (x, 0)) == REG
531 && GET_CODE (XEXP (x, 1)) == CONST_INT)
532 mark_reg_pointer (XEXP (x, 0), 1);
534 /* OLDX may have been the address on a temporary. Update the address
535 to indicate that X is now used. */
536 update_temp_slot_address (oldx, x);
541 /* Like `memory_address' but pretend `flag_force_addr' is 0. */
544 memory_address_noforce (mode, x)
545 enum machine_mode mode;
548 int ambient_force_addr = flag_force_addr;
552 val = memory_address (mode, x);
553 flag_force_addr = ambient_force_addr;
557 /* Convert a mem ref into one with a valid memory address.
558 Pass through anything else unchanged. */
564 if (GET_CODE (ref) != MEM)
566 if (memory_address_p (GET_MODE (ref), XEXP (ref, 0)))
568 /* Don't alter REF itself, since that is probably a stack slot. */
569 return change_address (ref, GET_MODE (ref), XEXP (ref, 0));
572 /* Return a modified copy of X with its memory address copied
573 into a temporary register to protect it from side effects.
574 If X is not a MEM, it is returned unchanged (and not copied).
575 Perhaps even if it is a MEM, if there is no need to change it. */
582 if (GET_CODE (x) != MEM)
585 if (rtx_unstable_p (addr))
587 rtx temp = copy_all_regs (addr);
589 if (GET_CODE (temp) != REG)
590 temp = copy_to_reg (temp);
591 mem = gen_rtx_MEM (GET_MODE (x), temp);
593 /* Mark returned memref with in_struct if it's in an array or
594 structure. Copy const and volatile from original memref. */
596 MEM_IN_STRUCT_P (mem) = MEM_IN_STRUCT_P (x) || GET_CODE (addr) == PLUS;
597 RTX_UNCHANGING_P (mem) = RTX_UNCHANGING_P (x);
598 MEM_VOLATILE_P (mem) = MEM_VOLATILE_P (x);
600 /* Since the new MEM is just like the old X, it can alias only
601 the things that X could. */
602 MEM_ALIAS_SET (mem) = MEM_ALIAS_SET (x);
609 /* Copy the value or contents of X to a new temp reg and return that reg. */
615 register rtx temp = gen_reg_rtx (GET_MODE (x));
617 /* If not an operand, must be an address with PLUS and MULT so
618 do the computation. */
619 if (! general_operand (x, VOIDmode))
620 x = force_operand (x, temp);
623 emit_move_insn (temp, x);
628 /* Like copy_to_reg but always give the new register mode Pmode
629 in case X is a constant. */
635 return copy_to_mode_reg (Pmode, x);
638 /* Like copy_to_reg but always give the new register mode MODE
639 in case X is a constant. */
642 copy_to_mode_reg (mode, x)
643 enum machine_mode mode;
646 register rtx temp = gen_reg_rtx (mode);
648 /* If not an operand, must be an address with PLUS and MULT so
649 do the computation. */
650 if (! general_operand (x, VOIDmode))
651 x = force_operand (x, temp);
653 if (GET_MODE (x) != mode && GET_MODE (x) != VOIDmode)
656 emit_move_insn (temp, x);
660 /* Load X into a register if it is not already one.
661 Use mode MODE for the register.
662 X should be valid for mode MODE, but it may be a constant which
663 is valid for all integer modes; that's why caller must specify MODE.
665 The caller must not alter the value in the register we return,
666 since we mark it as a "constant" register. */
670 enum machine_mode mode;
673 register rtx temp, insn, set;
675 if (GET_CODE (x) == REG)
677 temp = gen_reg_rtx (mode);
678 insn = emit_move_insn (temp, x);
680 /* Let optimizers know that TEMP's value never changes
681 and that X can be substituted for it. Don't get confused
682 if INSN set something else (such as a SUBREG of TEMP). */
684 && (set = single_set (insn)) != 0
685 && SET_DEST (set) == temp)
687 rtx note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
692 REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUAL, x, REG_NOTES (insn));
697 /* If X is a memory ref, copy its contents to a new temp reg and return
698 that reg. Otherwise, return X. */
705 if (GET_CODE (x) != MEM || GET_MODE (x) == BLKmode)
707 temp = gen_reg_rtx (GET_MODE (x));
708 emit_move_insn (temp, x);
712 /* Copy X to TARGET (if it's nonzero and a reg)
713 or to a new temp reg and return that reg.
714 MODE is the mode to use for X in case it is a constant. */
717 copy_to_suggested_reg (x, target, mode)
719 enum machine_mode mode;
723 if (target && GET_CODE (target) == REG)
726 temp = gen_reg_rtx (mode);
728 emit_move_insn (temp, x);
732 /* Return the mode to use to store a scalar of TYPE and MODE.
733 PUNSIGNEDP points to the signedness of the type and may be adjusted
734 to show what signedness to use on extension operations.
736 FOR_CALL is non-zero if this call is promoting args for a call. */
739 promote_mode (type, mode, punsignedp, for_call)
741 enum machine_mode mode;
743 int for_call ATTRIBUTE_UNUSED;
745 enum tree_code code = TREE_CODE (type);
746 int unsignedp = *punsignedp;
748 #ifdef PROMOTE_FOR_CALL_ONLY
756 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
757 case CHAR_TYPE: case REAL_TYPE: case OFFSET_TYPE:
758 PROMOTE_MODE (mode, unsignedp, type);
762 #ifdef POINTERS_EXTEND_UNSIGNED
766 unsignedp = POINTERS_EXTEND_UNSIGNED;
774 *punsignedp = unsignedp;
778 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
779 This pops when ADJUST is positive. ADJUST need not be constant. */
782 adjust_stack (adjust)
786 adjust = protect_from_queue (adjust, 0);
788 if (adjust == const0_rtx)
791 temp = expand_binop (Pmode,
792 #ifdef STACK_GROWS_DOWNWARD
797 stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
800 if (temp != stack_pointer_rtx)
801 emit_move_insn (stack_pointer_rtx, temp);
804 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
805 This pushes when ADJUST is positive. ADJUST need not be constant. */
808 anti_adjust_stack (adjust)
812 adjust = protect_from_queue (adjust, 0);
814 if (adjust == const0_rtx)
817 temp = expand_binop (Pmode,
818 #ifdef STACK_GROWS_DOWNWARD
823 stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
826 if (temp != stack_pointer_rtx)
827 emit_move_insn (stack_pointer_rtx, temp);
830 /* Round the size of a block to be pushed up to the boundary required
831 by this machine. SIZE is the desired size, which need not be constant. */
837 #ifdef PREFERRED_STACK_BOUNDARY
838 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
841 if (GET_CODE (size) == CONST_INT)
843 int new = (INTVAL (size) + align - 1) / align * align;
844 if (INTVAL (size) != new)
845 size = GEN_INT (new);
849 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
850 but we know it can't. So add ourselves and then do
852 size = expand_binop (Pmode, add_optab, size, GEN_INT (align - 1),
853 NULL_RTX, 1, OPTAB_LIB_WIDEN);
854 size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, GEN_INT (align),
856 size = expand_mult (Pmode, size, GEN_INT (align), NULL_RTX, 1);
858 #endif /* PREFERRED_STACK_BOUNDARY */
862 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
863 to a previously-created save area. If no save area has been allocated,
864 this function will allocate one. If a save area is specified, it
865 must be of the proper mode.
867 The insns are emitted after insn AFTER, if nonzero, otherwise the insns
868 are emitted at the current position. */
871 emit_stack_save (save_level, psave, after)
872 enum save_level save_level;
877 /* The default is that we use a move insn and save in a Pmode object. */
878 rtx (*fcn) PROTO ((rtx, rtx)) = gen_move_insn;
879 enum machine_mode mode = STACK_SAVEAREA_MODE (save_level);
881 /* See if this machine has anything special to do for this kind of save. */
884 #ifdef HAVE_save_stack_block
886 if (HAVE_save_stack_block)
887 fcn = gen_save_stack_block;
890 #ifdef HAVE_save_stack_function
892 if (HAVE_save_stack_function)
893 fcn = gen_save_stack_function;
896 #ifdef HAVE_save_stack_nonlocal
898 if (HAVE_save_stack_nonlocal)
899 fcn = gen_save_stack_nonlocal;
906 /* If there is no save area and we have to allocate one, do so. Otherwise
907 verify the save area is the proper mode. */
911 if (mode != VOIDmode)
913 if (save_level == SAVE_NONLOCAL)
914 *psave = sa = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
916 *psave = sa = gen_reg_rtx (mode);
921 if (mode == VOIDmode || GET_MODE (sa) != mode)
930 /* We must validize inside the sequence, to ensure that any instructions
931 created by the validize call also get moved to the right place. */
933 sa = validize_mem (sa);
934 emit_insn (fcn (sa, stack_pointer_rtx));
935 seq = gen_sequence ();
937 emit_insn_after (seq, after);
942 sa = validize_mem (sa);
943 emit_insn (fcn (sa, stack_pointer_rtx));
947 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
948 area made by emit_stack_save. If it is zero, we have nothing to do.
950 Put any emitted insns after insn AFTER, if nonzero, otherwise at
954 emit_stack_restore (save_level, sa, after)
955 enum save_level save_level;
959 /* The default is that we use a move insn. */
960 rtx (*fcn) PROTO ((rtx, rtx)) = gen_move_insn;
962 /* See if this machine has anything special to do for this kind of save. */
965 #ifdef HAVE_restore_stack_block
967 if (HAVE_restore_stack_block)
968 fcn = gen_restore_stack_block;
971 #ifdef HAVE_restore_stack_function
973 if (HAVE_restore_stack_function)
974 fcn = gen_restore_stack_function;
977 #ifdef HAVE_restore_stack_nonlocal
979 if (HAVE_restore_stack_nonlocal)
980 fcn = gen_restore_stack_nonlocal;
988 sa = validize_mem (sa);
995 emit_insn (fcn (stack_pointer_rtx, sa));
996 seq = gen_sequence ();
998 emit_insn_after (seq, after);
1001 emit_insn (fcn (stack_pointer_rtx, sa));
1004 #ifdef SETJMP_VIA_SAVE_AREA
1005 /* Optimize RTL generated by allocate_dynamic_stack_space for targets
1006 where SETJMP_VIA_SAVE_AREA is true. The problem is that on these
1007 platforms, the dynamic stack space used can corrupt the original
1008 frame, thus causing a crash if a longjmp unwinds to it. */
1011 optimize_save_area_alloca (insns)
1016 for (insn = insns; insn; insn = NEXT_INSN(insn))
1020 if (GET_CODE (insn) != INSN)
1023 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
1025 if (REG_NOTE_KIND (note) != REG_SAVE_AREA)
1028 if (!current_function_calls_setjmp)
1030 rtx pat = PATTERN (insn);
1032 /* If we do not see the note in a pattern matching
1033 these precise characteristics, we did something
1034 entirely wrong in allocate_dynamic_stack_space.
1036 Note, one way this could happen is if SETJMP_VIA_SAVE_AREA
1037 was defined on a machine where stacks grow towards higher
1040 Right now only supported port with stack that grow upward
1041 is the HPPA and it does not define SETJMP_VIA_SAVE_AREA. */
1042 if (GET_CODE (pat) != SET
1043 || SET_DEST (pat) != stack_pointer_rtx
1044 || GET_CODE (SET_SRC (pat)) != MINUS
1045 || XEXP (SET_SRC (pat), 0) != stack_pointer_rtx)
1048 /* This will now be transformed into a (set REG REG)
1049 so we can just blow away all the other notes. */
1050 XEXP (SET_SRC (pat), 1) = XEXP (note, 0);
1051 REG_NOTES (insn) = NULL_RTX;
1055 /* setjmp was called, we must remove the REG_SAVE_AREA
1056 note so that later passes do not get confused by its
1058 if (note == REG_NOTES (insn))
1060 REG_NOTES (insn) = XEXP (note, 1);
1066 for (srch = REG_NOTES (insn); srch; srch = XEXP (srch, 1))
1067 if (XEXP (srch, 1) == note)
1070 if (srch == NULL_RTX)
1073 XEXP (srch, 1) = XEXP (note, 1);
1076 /* Once we've seen the note of interest, we need not look at
1077 the rest of them. */
1082 #endif /* SETJMP_VIA_SAVE_AREA */
1084 /* Return an rtx representing the address of an area of memory dynamically
1085 pushed on the stack. This region of memory is always aligned to
1086 a multiple of BIGGEST_ALIGNMENT.
1088 Any required stack pointer alignment is preserved.
1090 SIZE is an rtx representing the size of the area.
1091 TARGET is a place in which the address can be placed.
1093 KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */
1096 allocate_dynamic_stack_space (size, target, known_align)
1101 #ifdef SETJMP_VIA_SAVE_AREA
1102 rtx setjmpless_size = NULL_RTX;
1105 /* If we're asking for zero bytes, it doesn't matter what we point
1106 to since we can't dereference it. But return a reasonable
1108 if (size == const0_rtx)
1109 return virtual_stack_dynamic_rtx;
1111 /* Otherwise, show we're calling alloca or equivalent. */
1112 current_function_calls_alloca = 1;
1114 /* Ensure the size is in the proper mode. */
1115 if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
1116 size = convert_to_mode (Pmode, size, 1);
1118 /* We will need to ensure that the address we return is aligned to
1119 BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
1120 always know its final value at this point in the compilation (it
1121 might depend on the size of the outgoing parameter lists, for
1122 example), so we must align the value to be returned in that case.
1123 (Note that STACK_DYNAMIC_OFFSET will have a default non-zero value if
1124 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1125 We must also do an alignment operation on the returned value if
1126 the stack pointer alignment is less strict that BIGGEST_ALIGNMENT.
1128 If we have to align, we must leave space in SIZE for the hole
1129 that might result from the alignment operation. */
1131 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET) || ! defined (PREFERRED_STACK_BOUNDARY)
1132 #define MUST_ALIGN 1
1134 #define MUST_ALIGN (PREFERRED_STACK_BOUNDARY < BIGGEST_ALIGNMENT)
1139 if (GET_CODE (size) == CONST_INT)
1140 size = GEN_INT (INTVAL (size)
1141 + (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1));
1143 size = expand_binop (Pmode, add_optab, size,
1144 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
1145 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1148 #ifdef SETJMP_VIA_SAVE_AREA
1149 /* If setjmp restores regs from a save area in the stack frame,
1150 avoid clobbering the reg save area. Note that the offset of
1151 virtual_incoming_args_rtx includes the preallocated stack args space.
1152 It would be no problem to clobber that, but it's on the wrong side
1153 of the old save area. */
1156 = expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx,
1157 stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN);
1159 if (!current_function_calls_setjmp)
1161 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
1163 /* See optimize_save_area_alloca to understand what is being
1166 #if !defined(PREFERRED_STACK_BOUNDARY) || !defined(MUST_ALIGN) || (PREFERRED_STACK_BOUNDARY != BIGGEST_ALIGNMENT)
1167 /* If anyone creates a target with these characteristics, let them
1168 know that our optimization cannot work correctly in such a case. */
1172 if (GET_CODE (size) == CONST_INT)
1174 int new = INTVAL (size) / align * align;
1176 if (INTVAL (size) != new)
1177 setjmpless_size = GEN_INT (new);
1179 setjmpless_size = size;
1183 /* Since we know overflow is not possible, we avoid using
1184 CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */
1185 setjmpless_size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size,
1186 GEN_INT (align), NULL_RTX, 1);
1187 setjmpless_size = expand_mult (Pmode, setjmpless_size,
1188 GEN_INT (align), NULL_RTX, 1);
1190 /* Our optimization works based upon being able to perform a simple
1191 transformation of this RTL into a (set REG REG) so make sure things
1192 did in fact end up in a REG. */
1193 if (!arith_operand (setjmpless_size, Pmode))
1194 setjmpless_size = force_reg (Pmode, setjmpless_size);
1197 size = expand_binop (Pmode, add_optab, size, dynamic_offset,
1198 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1200 #endif /* SETJMP_VIA_SAVE_AREA */
1202 /* Round the size to a multiple of the required stack alignment.
1203 Since the stack if presumed to be rounded before this allocation,
1204 this will maintain the required alignment.
1206 If the stack grows downward, we could save an insn by subtracting
1207 SIZE from the stack pointer and then aligning the stack pointer.
1208 The problem with this is that the stack pointer may be unaligned
1209 between the execution of the subtraction and alignment insns and
1210 some machines do not allow this. Even on those that do, some
1211 signal handlers malfunction if a signal should occur between those
1212 insns. Since this is an extremely rare event, we have no reliable
1213 way of knowing which systems have this problem. So we avoid even
1214 momentarily mis-aligning the stack. */
1216 #ifdef PREFERRED_STACK_BOUNDARY
1217 /* If we added a variable amount to SIZE,
1218 we can no longer assume it is aligned. */
1219 #if !defined (SETJMP_VIA_SAVE_AREA)
1220 if (MUST_ALIGN || known_align % PREFERRED_STACK_BOUNDARY != 0)
1222 size = round_push (size);
1225 do_pending_stack_adjust ();
1227 /* If needed, check that we have the required amount of stack. Take into
1228 account what has already been checked. */
1229 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
1230 probe_stack_range (STACK_CHECK_MAX_FRAME_SIZE + STACK_CHECK_PROTECT, size);
1232 /* Don't use a TARGET that isn't a pseudo. */
1233 if (target == 0 || GET_CODE (target) != REG
1234 || REGNO (target) < FIRST_PSEUDO_REGISTER)
1235 target = gen_reg_rtx (Pmode);
1237 mark_reg_pointer (target, known_align / BITS_PER_UNIT);
1239 /* Perform the required allocation from the stack. Some systems do
1240 this differently than simply incrementing/decrementing from the
1241 stack pointer, such as acquiring the space by calling malloc(). */
1242 #ifdef HAVE_allocate_stack
1243 if (HAVE_allocate_stack)
1245 enum machine_mode mode = STACK_SIZE_MODE;
1247 if (insn_operand_predicate[(int) CODE_FOR_allocate_stack][0]
1248 && ! ((*insn_operand_predicate[(int) CODE_FOR_allocate_stack][0])
1250 target = copy_to_mode_reg (Pmode, target);
1251 size = convert_modes (mode, ptr_mode, size, 1);
1252 if (insn_operand_predicate[(int) CODE_FOR_allocate_stack][1]
1253 && ! ((*insn_operand_predicate[(int) CODE_FOR_allocate_stack][1])
1255 size = copy_to_mode_reg (mode, size);
1257 emit_insn (gen_allocate_stack (target, size));
1262 #ifndef STACK_GROWS_DOWNWARD
1263 emit_move_insn (target, virtual_stack_dynamic_rtx);
1265 size = convert_modes (Pmode, ptr_mode, size, 1);
1266 anti_adjust_stack (size);
1267 #ifdef SETJMP_VIA_SAVE_AREA
1268 if (setjmpless_size != NULL_RTX)
1270 rtx note_target = get_last_insn ();
1272 REG_NOTES (note_target)
1273 = gen_rtx_EXPR_LIST (REG_SAVE_AREA, setjmpless_size,
1274 REG_NOTES (note_target));
1276 #endif /* SETJMP_VIA_SAVE_AREA */
1277 #ifdef STACK_GROWS_DOWNWARD
1278 emit_move_insn (target, virtual_stack_dynamic_rtx);
1284 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1285 but we know it can't. So add ourselves and then do
1287 target = expand_binop (Pmode, add_optab, target,
1288 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
1289 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1290 target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target,
1291 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
1293 target = expand_mult (Pmode, target,
1294 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
1298 /* Some systems require a particular insn to refer to the stack
1299 to make the pages exist. */
1302 emit_insn (gen_probe ());
1305 /* Record the new stack level for nonlocal gotos. */
1306 if (nonlocal_goto_handler_slots != 0)
1307 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
1312 /* Emit one stack probe at ADDRESS, an address within the stack. */
1315 emit_stack_probe (address)
1318 rtx memref = gen_rtx_MEM (word_mode, address);
1320 MEM_VOLATILE_P (memref) = 1;
1322 if (STACK_CHECK_PROBE_LOAD)
1323 emit_move_insn (gen_reg_rtx (word_mode), memref);
1325 emit_move_insn (memref, const0_rtx);
1328 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1329 FIRST is a constant and size is a Pmode RTX. These are offsets from the
1330 current stack pointer. STACK_GROWS_DOWNWARD says whether to add or
1331 subtract from the stack. If SIZE is constant, this is done
1332 with a fixed number of probes. Otherwise, we must make a loop. */
1334 #ifdef STACK_GROWS_DOWNWARD
1335 #define STACK_GROW_OP MINUS
1337 #define STACK_GROW_OP PLUS
1341 probe_stack_range (first, size)
1342 HOST_WIDE_INT first;
1345 /* First see if we have an insn to check the stack. Use it if so. */
1346 #ifdef HAVE_check_stack
1347 if (HAVE_check_stack)
1350 = force_operand (gen_rtx_STACK_GROW_OP (Pmode,
1352 plus_constant (size, first)),
1355 if (insn_operand_predicate[(int) CODE_FOR_check_stack][0]
1356 && ! ((*insn_operand_predicate[(int) CODE_FOR_check_stack][0])
1357 (last_address, Pmode)))
1358 last_address = copy_to_mode_reg (Pmode, last_address);
1360 emit_insn (gen_check_stack (last_address));
1365 /* If we have to generate explicit probes, see if we have a constant
1366 small number of them to generate. If so, that's the easy case. */
1367 if (GET_CODE (size) == CONST_INT
1368 && INTVAL (size) < 10 * STACK_CHECK_PROBE_INTERVAL)
1370 HOST_WIDE_INT offset;
1372 /* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL
1373 for values of N from 1 until it exceeds LAST. If only one
1374 probe is needed, this will not generate any code. Then probe
1376 for (offset = first + STACK_CHECK_PROBE_INTERVAL;
1377 offset < INTVAL (size);
1378 offset = offset + STACK_CHECK_PROBE_INTERVAL)
1379 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1383 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1385 plus_constant (size, first)));
1388 /* In the variable case, do the same as above, but in a loop. We emit loop
1389 notes so that loop optimization can be done. */
1393 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1395 GEN_INT (first + STACK_CHECK_PROBE_INTERVAL)),
1398 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1400 plus_constant (size, first)),
1402 rtx incr = GEN_INT (STACK_CHECK_PROBE_INTERVAL);
1403 rtx loop_lab = gen_label_rtx ();
1404 rtx test_lab = gen_label_rtx ();
1405 rtx end_lab = gen_label_rtx ();
1408 if (GET_CODE (test_addr) != REG
1409 || REGNO (test_addr) < FIRST_PSEUDO_REGISTER)
1410 test_addr = force_reg (Pmode, test_addr);
1412 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
1413 emit_jump (test_lab);
1415 emit_label (loop_lab);
1416 emit_stack_probe (test_addr);
1418 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
1420 #ifdef STACK_GROWS_DOWNWARD
1421 #define CMP_OPCODE GTU
1422 temp = expand_binop (Pmode, sub_optab, test_addr, incr, test_addr,
1425 #define CMP_OPCODE LTU
1426 temp = expand_binop (Pmode, add_optab, test_addr, incr, test_addr,
1430 if (temp != test_addr)
1433 emit_label (test_lab);
1434 emit_cmp_insn (test_addr, last_addr, CMP_OPCODE, NULL_RTX, Pmode, 1, 0);
1435 emit_jump_insn ((*bcc_gen_fctn[(int) CMP_OPCODE]) (loop_lab));
1436 emit_jump (end_lab);
1437 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
1438 emit_label (end_lab);
1440 /* If will be doing stupid optimization, show test_addr is still live. */
1442 emit_insn (gen_rtx_USE (VOIDmode, test_addr));
1444 emit_stack_probe (last_addr);
1448 /* Return an rtx representing the register or memory location
1449 in which a scalar value of data type VALTYPE
1450 was returned by a function call to function FUNC.
1451 FUNC is a FUNCTION_DECL node if the precise function is known,
1455 hard_function_value (valtype, func)
1459 rtx val = FUNCTION_VALUE (valtype, func);
1460 if (GET_CODE (val) == REG
1461 && GET_MODE (val) == BLKmode)
1463 int bytes = int_size_in_bytes (valtype);
1464 enum machine_mode tmpmode;
1465 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
1466 tmpmode != MAX_MACHINE_MODE;
1467 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
1469 /* Have we found a large enough mode? */
1470 if (GET_MODE_SIZE (tmpmode) >= bytes)
1474 /* No suitable mode found. */
1475 if (tmpmode == MAX_MACHINE_MODE)
1478 PUT_MODE (val, tmpmode);
1483 /* Return an rtx representing the register or memory location
1484 in which a scalar value of mode MODE was returned by a library call. */
1487 hard_libcall_value (mode)
1488 enum machine_mode mode;
1490 return LIBCALL_VALUE (mode);
1493 /* Look up the tree code for a given rtx code
1494 to provide the arithmetic operation for REAL_ARITHMETIC.
1495 The function returns an int because the caller may not know
1496 what `enum tree_code' means. */
1499 rtx_to_tree_code (code)
1502 enum tree_code tcode;
1525 tcode = LAST_AND_UNUSED_TREE_CODE;
1528 return ((int) tcode);