1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987, 91, 94, 95, 96, 1997 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 static rtx break_out_memory_refs PROTO((rtx));
35 static void emit_stack_probe PROTO((rtx));
36 /* Return an rtx for the sum of X and the integer C.
38 This function should be used via the `plus_constant' macro. */
41 plus_constant_wide (x, c)
43 register HOST_WIDE_INT c;
45 register RTX_CODE code;
46 register enum machine_mode mode;
60 return GEN_INT (INTVAL (x) + c);
64 HOST_WIDE_INT l1 = CONST_DOUBLE_LOW (x);
65 HOST_WIDE_INT h1 = CONST_DOUBLE_HIGH (x);
67 HOST_WIDE_INT h2 = c < 0 ? ~0 : 0;
70 add_double (l1, h1, l2, h2, &lv, &hv);
72 return immed_double_const (lv, hv, VOIDmode);
76 /* If this is a reference to the constant pool, try replacing it with
77 a reference to a new constant. If the resulting address isn't
78 valid, don't return it because we have no way to validize it. */
79 if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF
80 && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)))
82 /* Any rtl we create here must go in a saveable obstack, since
83 we might have been called from within combine. */
84 push_obstacks_nochange ();
85 rtl_in_saveable_obstack ();
87 = force_const_mem (GET_MODE (x),
88 plus_constant (get_pool_constant (XEXP (x, 0)),
91 if (memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
97 /* If adding to something entirely constant, set a flag
98 so that we can add a CONST around the result. */
109 /* The interesting case is adding the integer to a sum.
110 Look for constant term in the sum and combine
111 with C. For an integer constant term, we make a combined
112 integer. For a constant term that is not an explicit integer,
113 we cannot really combine, but group them together anyway.
115 Use a recursive call in case the remaining operand is something
116 that we handle specially, such as a SYMBOL_REF. */
118 if (GET_CODE (XEXP (x, 1)) == CONST_INT)
119 return plus_constant (XEXP (x, 0), c + INTVAL (XEXP (x, 1)));
120 else if (CONSTANT_P (XEXP (x, 0)))
121 return gen_rtx_PLUS (mode,
122 plus_constant (XEXP (x, 0), c),
124 else if (CONSTANT_P (XEXP (x, 1)))
125 return gen_rtx_PLUS (mode,
127 plus_constant (XEXP (x, 1), c));
135 x = gen_rtx_PLUS (mode, x, GEN_INT (c));
137 if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
139 else if (all_constant)
140 return gen_rtx_CONST (mode, x);
145 /* This is the same as `plus_constant', except that it handles LO_SUM.
147 This function should be used via the `plus_constant_for_output' macro. */
150 plus_constant_for_output_wide (x, c)
152 register HOST_WIDE_INT c;
154 register RTX_CODE code = GET_CODE (x);
155 register enum machine_mode mode = GET_MODE (x);
156 int all_constant = 0;
158 if (GET_CODE (x) == LO_SUM)
159 return gen_rtx_LO_SUM (mode, XEXP (x, 0),
160 plus_constant_for_output (XEXP (x, 1), c));
163 return plus_constant (x, c);
166 /* If X is a sum, return a new sum like X but lacking any constant terms.
167 Add all the removed constant terms into *CONSTPTR.
168 X itself is not altered. The result != X if and only if
169 it is not isomorphic to X. */
172 eliminate_constant_term (x, constptr)
179 if (GET_CODE (x) != PLUS)
182 /* First handle constants appearing at this level explicitly. */
183 if (GET_CODE (XEXP (x, 1)) == CONST_INT
184 && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr,
186 && GET_CODE (tem) == CONST_INT)
189 return eliminate_constant_term (XEXP (x, 0), constptr);
193 x0 = eliminate_constant_term (XEXP (x, 0), &tem);
194 x1 = eliminate_constant_term (XEXP (x, 1), &tem);
195 if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0))
196 && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x),
198 && GET_CODE (tem) == CONST_INT)
201 return gen_rtx_PLUS (GET_MODE (x), x0, x1);
207 /* Returns the insn that next references REG after INSN, or 0
208 if REG is clobbered before next referenced or we cannot find
209 an insn that references REG in a straight-line piece of code. */
212 find_next_ref (reg, insn)
218 for (insn = NEXT_INSN (insn); insn; insn = next)
220 next = NEXT_INSN (insn);
221 if (GET_CODE (insn) == NOTE)
223 if (GET_CODE (insn) == CODE_LABEL
224 || GET_CODE (insn) == BARRIER)
226 if (GET_CODE (insn) == INSN
227 || GET_CODE (insn) == JUMP_INSN
228 || GET_CODE (insn) == CALL_INSN)
230 if (reg_set_p (reg, insn))
232 if (reg_mentioned_p (reg, PATTERN (insn)))
234 if (GET_CODE (insn) == JUMP_INSN)
236 if (simplejump_p (insn))
237 next = JUMP_LABEL (insn);
241 if (GET_CODE (insn) == CALL_INSN
242 && REGNO (reg) < FIRST_PSEUDO_REGISTER
243 && call_used_regs[REGNO (reg)])
252 /* Return an rtx for the size in bytes of the value of EXP. */
258 tree size = size_in_bytes (TREE_TYPE (exp));
260 if (TREE_CODE (size) != INTEGER_CST
261 && contains_placeholder_p (size))
262 size = build (WITH_RECORD_EXPR, sizetype, size, exp);
264 return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype),
265 EXPAND_MEMORY_USE_BAD);
268 /* Return a copy of X in which all memory references
269 and all constants that involve symbol refs
270 have been replaced with new temporary registers.
271 Also emit code to load the memory locations and constants
272 into those registers.
274 If X contains no such constants or memory references,
275 X itself (not a copy) is returned.
277 If a constant is found in the address that is not a legitimate constant
278 in an insn, it is left alone in the hope that it might be valid in the
281 X may contain no arithmetic except addition, subtraction and multiplication.
282 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
285 break_out_memory_refs (x)
288 if (GET_CODE (x) == MEM
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 register rtx op0 = break_out_memory_refs (XEXP (x, 0));
296 register 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);
305 #ifdef POINTERS_EXTEND_UNSIGNED
307 /* Given X, a memory address in ptr_mode, convert it to an address
308 in Pmode, or vice versa (TO_MODE says which way). We take advantage of
309 the fact that pointers are not allowed to overflow by commuting arithmetic
310 operations over conversions so that address arithmetic insns can be
314 convert_memory_address (to_mode, x)
315 enum machine_mode to_mode;
318 enum machine_mode from_mode = to_mode == ptr_mode ? Pmode : ptr_mode;
321 /* Here we handle some special cases. If none of them apply, fall through
322 to the default case. */
323 switch (GET_CODE (x))
330 temp = gen_rtx_LABEL_REF (to_mode, XEXP (x, 0));
331 LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x);
335 temp = gen_rtx_SYMBOL_REF (to_mode, XSTR (x, 0));
336 SYMBOL_REF_FLAG (temp) = SYMBOL_REF_FLAG (x);
337 CONSTANT_POOL_ADDRESS_P (temp) = CONSTANT_POOL_ADDRESS_P (x);
341 return gen_rtx_CONST (to_mode,
342 convert_memory_address (to_mode, XEXP (x, 0)));
346 /* For addition the second operand is a small constant, we can safely
347 permute the conversion and addition operation. We can always safely
348 permute them if we are making the address narrower. In addition,
349 always permute the operations if this is a constant. */
350 if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)
351 || (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == CONST_INT
352 && (INTVAL (XEXP (x, 1)) + 20000 < 40000
353 || CONSTANT_P (XEXP (x, 0)))))
354 return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
355 convert_memory_address (to_mode, XEXP (x, 0)),
356 convert_memory_address (to_mode, XEXP (x, 1)));
363 return convert_modes (to_mode, from_mode,
364 x, POINTERS_EXTEND_UNSIGNED);
368 /* Given a memory address or facsimile X, construct a new address,
369 currently equivalent, that is stable: future stores won't change it.
371 X must be composed of constants, register and memory references
372 combined with addition, subtraction and multiplication:
373 in other words, just what you can get from expand_expr if sum_ok is 1.
375 Works by making copies of all regs and memory locations used
376 by X and combining them the same way X does.
377 You could also stabilize the reference to this address
378 by copying the address to a register with copy_to_reg;
379 but then you wouldn't get indexed addressing in the reference. */
385 if (GET_CODE (x) == REG)
387 if (REGNO (x) != FRAME_POINTER_REGNUM
388 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
389 && REGNO (x) != HARD_FRAME_POINTER_REGNUM
394 else if (GET_CODE (x) == MEM)
396 else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
397 || GET_CODE (x) == MULT)
399 register rtx op0 = copy_all_regs (XEXP (x, 0));
400 register rtx op1 = copy_all_regs (XEXP (x, 1));
401 if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
402 x = gen_rtx_fmt_ee (GET_CODE (x), Pmode, op0, op1);
407 /* Return something equivalent to X but valid as a memory address
408 for something of mode MODE. When X is not itself valid, this
409 works by copying X or subexpressions of it into registers. */
412 memory_address (mode, x)
413 enum machine_mode mode;
416 register rtx oldx = x;
418 if (GET_CODE (x) == ADDRESSOF)
421 #ifdef POINTERS_EXTEND_UNSIGNED
422 if (GET_MODE (x) == ptr_mode)
423 x = convert_memory_address (Pmode, x);
426 /* By passing constant addresses thru registers
427 we get a chance to cse them. */
428 if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x))
429 x = force_reg (Pmode, x);
431 /* Accept a QUEUED that refers to a REG
432 even though that isn't a valid address.
433 On attempting to put this in an insn we will call protect_from_queue
434 which will turn it into a REG, which is valid. */
435 else if (GET_CODE (x) == QUEUED
436 && GET_CODE (QUEUED_VAR (x)) == REG)
439 /* We get better cse by rejecting indirect addressing at this stage.
440 Let the combiner create indirect addresses where appropriate.
441 For now, generate the code so that the subexpressions useful to share
442 are visible. But not if cse won't be done! */
445 if (! cse_not_expected && GET_CODE (x) != REG)
446 x = break_out_memory_refs (x);
448 /* At this point, any valid address is accepted. */
449 GO_IF_LEGITIMATE_ADDRESS (mode, x, win);
451 /* If it was valid before but breaking out memory refs invalidated it,
452 use it the old way. */
453 if (memory_address_p (mode, oldx))
456 /* Perform machine-dependent transformations on X
457 in certain cases. This is not necessary since the code
458 below can handle all possible cases, but machine-dependent
459 transformations can make better code. */
460 LEGITIMIZE_ADDRESS (x, oldx, mode, win);
462 /* PLUS and MULT can appear in special ways
463 as the result of attempts to make an address usable for indexing.
464 Usually they are dealt with by calling force_operand, below.
465 But a sum containing constant terms is special
466 if removing them makes the sum a valid address:
467 then we generate that address in a register
468 and index off of it. We do this because it often makes
469 shorter code, and because the addresses thus generated
470 in registers often become common subexpressions. */
471 if (GET_CODE (x) == PLUS)
473 rtx constant_term = const0_rtx;
474 rtx y = eliminate_constant_term (x, &constant_term);
475 if (constant_term == const0_rtx
476 || ! memory_address_p (mode, y))
477 x = force_operand (x, NULL_RTX);
480 y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term);
481 if (! memory_address_p (mode, y))
482 x = force_operand (x, NULL_RTX);
488 else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS)
489 x = force_operand (x, NULL_RTX);
491 /* If we have a register that's an invalid address,
492 it must be a hard reg of the wrong class. Copy it to a pseudo. */
493 else if (GET_CODE (x) == REG)
496 /* Last resort: copy the value to a register, since
497 the register is a valid address. */
499 x = force_reg (Pmode, x);
506 if (flag_force_addr && ! cse_not_expected && GET_CODE (x) != REG
507 /* Don't copy an addr via a reg if it is one of our stack slots. */
508 && ! (GET_CODE (x) == PLUS
509 && (XEXP (x, 0) == virtual_stack_vars_rtx
510 || XEXP (x, 0) == virtual_incoming_args_rtx)))
512 if (general_operand (x, Pmode))
513 x = force_reg (Pmode, x);
515 x = force_operand (x, NULL_RTX);
521 /* If we didn't change the address, we are done. Otherwise, mark
522 a reg as a pointer if we have REG or REG + CONST_INT. */
525 else if (GET_CODE (x) == REG)
526 mark_reg_pointer (x, 1);
527 else if (GET_CODE (x) == PLUS
528 && GET_CODE (XEXP (x, 0)) == REG
529 && GET_CODE (XEXP (x, 1)) == CONST_INT)
530 mark_reg_pointer (XEXP (x, 0), 1);
532 /* OLDX may have been the address on a temporary. Update the address
533 to indicate that X is now used. */
534 update_temp_slot_address (oldx, x);
539 /* Like `memory_address' but pretend `flag_force_addr' is 0. */
542 memory_address_noforce (mode, x)
543 enum machine_mode mode;
546 int ambient_force_addr = flag_force_addr;
550 val = memory_address (mode, x);
551 flag_force_addr = ambient_force_addr;
555 /* Convert a mem ref into one with a valid memory address.
556 Pass through anything else unchanged. */
562 if (GET_CODE (ref) != MEM)
564 if (memory_address_p (GET_MODE (ref), XEXP (ref, 0)))
566 /* Don't alter REF itself, since that is probably a stack slot. */
567 return change_address (ref, GET_MODE (ref), XEXP (ref, 0));
570 /* Return a modified copy of X with its memory address copied
571 into a temporary register to protect it from side effects.
572 If X is not a MEM, it is returned unchanged (and not copied).
573 Perhaps even if it is a MEM, if there is no need to change it. */
580 if (GET_CODE (x) != MEM)
583 if (rtx_unstable_p (addr))
585 rtx temp = copy_all_regs (addr);
587 if (GET_CODE (temp) != REG)
588 temp = copy_to_reg (temp);
589 mem = gen_rtx_MEM (GET_MODE (x), temp);
591 /* Mark returned memref with in_struct if it's in an array or
592 structure. Copy const and volatile from original memref. */
594 MEM_IN_STRUCT_P (mem) = MEM_IN_STRUCT_P (x) || GET_CODE (addr) == PLUS;
595 RTX_UNCHANGING_P (mem) = RTX_UNCHANGING_P (x);
596 MEM_VOLATILE_P (mem) = MEM_VOLATILE_P (x);
602 /* Copy the value or contents of X to a new temp reg and return that reg. */
608 register rtx temp = gen_reg_rtx (GET_MODE (x));
610 /* If not an operand, must be an address with PLUS and MULT so
611 do the computation. */
612 if (! general_operand (x, VOIDmode))
613 x = force_operand (x, temp);
616 emit_move_insn (temp, x);
621 /* Like copy_to_reg but always give the new register mode Pmode
622 in case X is a constant. */
628 return copy_to_mode_reg (Pmode, x);
631 /* Like copy_to_reg but always give the new register mode MODE
632 in case X is a constant. */
635 copy_to_mode_reg (mode, x)
636 enum machine_mode mode;
639 register rtx temp = gen_reg_rtx (mode);
641 /* If not an operand, must be an address with PLUS and MULT so
642 do the computation. */
643 if (! general_operand (x, VOIDmode))
644 x = force_operand (x, temp);
646 if (GET_MODE (x) != mode && GET_MODE (x) != VOIDmode)
649 emit_move_insn (temp, x);
653 /* Load X into a register if it is not already one.
654 Use mode MODE for the register.
655 X should be valid for mode MODE, but it may be a constant which
656 is valid for all integer modes; that's why caller must specify MODE.
658 The caller must not alter the value in the register we return,
659 since we mark it as a "constant" register. */
663 enum machine_mode mode;
666 register rtx temp, insn, set;
668 if (GET_CODE (x) == REG)
670 temp = gen_reg_rtx (mode);
671 insn = emit_move_insn (temp, x);
673 /* Let optimizers know that TEMP's value never changes
674 and that X can be substituted for it. Don't get confused
675 if INSN set something else (such as a SUBREG of TEMP). */
677 && (set = single_set (insn)) != 0
678 && SET_DEST (set) == temp)
680 rtx note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
685 REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUAL, x, REG_NOTES (insn));
690 /* If X is a memory ref, copy its contents to a new temp reg and return
691 that reg. Otherwise, return X. */
698 if (GET_CODE (x) != MEM || GET_MODE (x) == BLKmode)
700 temp = gen_reg_rtx (GET_MODE (x));
701 emit_move_insn (temp, x);
705 /* Copy X to TARGET (if it's nonzero and a reg)
706 or to a new temp reg and return that reg.
707 MODE is the mode to use for X in case it is a constant. */
710 copy_to_suggested_reg (x, target, mode)
712 enum machine_mode mode;
716 if (target && GET_CODE (target) == REG)
719 temp = gen_reg_rtx (mode);
721 emit_move_insn (temp, x);
725 /* Return the mode to use to store a scalar of TYPE and MODE.
726 PUNSIGNEDP points to the signedness of the type and may be adjusted
727 to show what signedness to use on extension operations.
729 FOR_CALL is non-zero if this call is promoting args for a call. */
732 promote_mode (type, mode, punsignedp, for_call)
734 enum machine_mode mode;
738 enum tree_code code = TREE_CODE (type);
739 int unsignedp = *punsignedp;
741 #ifdef PROMOTE_FOR_CALL_ONLY
749 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
750 case CHAR_TYPE: case REAL_TYPE: case OFFSET_TYPE:
751 PROMOTE_MODE (mode, unsignedp, type);
755 #ifdef POINTERS_EXTEND_UNSIGNED
759 unsignedp = POINTERS_EXTEND_UNSIGNED;
767 *punsignedp = unsignedp;
771 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
772 This pops when ADJUST is positive. ADJUST need not be constant. */
775 adjust_stack (adjust)
779 adjust = protect_from_queue (adjust, 0);
781 if (adjust == const0_rtx)
784 temp = expand_binop (Pmode,
785 #ifdef STACK_GROWS_DOWNWARD
790 stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
793 if (temp != stack_pointer_rtx)
794 emit_move_insn (stack_pointer_rtx, temp);
797 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
798 This pushes when ADJUST is positive. ADJUST need not be constant. */
801 anti_adjust_stack (adjust)
805 adjust = protect_from_queue (adjust, 0);
807 if (adjust == const0_rtx)
810 temp = expand_binop (Pmode,
811 #ifdef STACK_GROWS_DOWNWARD
816 stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
819 if (temp != stack_pointer_rtx)
820 emit_move_insn (stack_pointer_rtx, temp);
823 /* Round the size of a block to be pushed up to the boundary required
824 by this machine. SIZE is the desired size, which need not be constant. */
830 #ifdef STACK_BOUNDARY
831 int align = STACK_BOUNDARY / BITS_PER_UNIT;
834 if (GET_CODE (size) == CONST_INT)
836 int new = (INTVAL (size) + align - 1) / align * align;
837 if (INTVAL (size) != new)
838 size = GEN_INT (new);
842 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
843 but we know it can't. So add ourselves and then do
845 size = expand_binop (Pmode, add_optab, size, GEN_INT (align - 1),
846 NULL_RTX, 1, OPTAB_LIB_WIDEN);
847 size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, GEN_INT (align),
849 size = expand_mult (Pmode, size, GEN_INT (align), NULL_RTX, 1);
851 #endif /* STACK_BOUNDARY */
855 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
856 to a previously-created save area. If no save area has been allocated,
857 this function will allocate one. If a save area is specified, it
858 must be of the proper mode.
860 The insns are emitted after insn AFTER, if nonzero, otherwise the insns
861 are emitted at the current position. */
864 emit_stack_save (save_level, psave, after)
865 enum save_level save_level;
870 /* The default is that we use a move insn and save in a Pmode object. */
871 rtx (*fcn) () = gen_move_insn;
872 enum machine_mode mode = Pmode;
874 /* See if this machine has anything special to do for this kind of save. */
877 #ifdef HAVE_save_stack_block
879 if (HAVE_save_stack_block)
881 fcn = gen_save_stack_block;
882 mode = insn_operand_mode[CODE_FOR_save_stack_block][0];
886 #ifdef HAVE_save_stack_function
888 if (HAVE_save_stack_function)
890 fcn = gen_save_stack_function;
891 mode = insn_operand_mode[CODE_FOR_save_stack_function][0];
895 #ifdef HAVE_save_stack_nonlocal
897 if (HAVE_save_stack_nonlocal)
899 fcn = gen_save_stack_nonlocal;
900 mode = insn_operand_mode[(int) CODE_FOR_save_stack_nonlocal][0];
908 /* If there is no save area and we have to allocate one, do so. Otherwise
909 verify the save area is the proper mode. */
913 if (mode != VOIDmode)
915 if (save_level == SAVE_NONLOCAL)
916 *psave = sa = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
918 *psave = sa = gen_reg_rtx (mode);
923 if (mode == VOIDmode || GET_MODE (sa) != mode)
932 /* We must validize inside the sequence, to ensure that any instructions
933 created by the validize call also get moved to the right place. */
935 sa = validize_mem (sa);
936 emit_insn (fcn (sa, stack_pointer_rtx));
937 seq = gen_sequence ();
939 emit_insn_after (seq, after);
944 sa = validize_mem (sa);
945 emit_insn (fcn (sa, stack_pointer_rtx));
949 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
950 area made by emit_stack_save. If it is zero, we have nothing to do.
952 Put any emitted insns after insn AFTER, if nonzero, otherwise at
956 emit_stack_restore (save_level, sa, after)
957 enum save_level save_level;
961 /* The default is that we use a move insn. */
962 rtx (*fcn) () = gen_move_insn;
964 /* See if this machine has anything special to do for this kind of save. */
967 #ifdef HAVE_restore_stack_block
969 if (HAVE_restore_stack_block)
970 fcn = gen_restore_stack_block;
973 #ifdef HAVE_restore_stack_function
975 if (HAVE_restore_stack_function)
976 fcn = gen_restore_stack_function;
979 #ifdef HAVE_restore_stack_nonlocal
982 if (HAVE_restore_stack_nonlocal)
983 fcn = gen_restore_stack_nonlocal;
991 sa = validize_mem (sa);
998 emit_insn (fcn (stack_pointer_rtx, sa));
999 seq = gen_sequence ();
1001 emit_insn_after (seq, after);
1004 emit_insn (fcn (stack_pointer_rtx, sa));
1007 /* Return an rtx representing the address of an area of memory dynamically
1008 pushed on the stack. This region of memory is always aligned to
1009 a multiple of BIGGEST_ALIGNMENT.
1011 Any required stack pointer alignment is preserved.
1013 SIZE is an rtx representing the size of the area.
1014 TARGET is a place in which the address can be placed.
1016 KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */
1019 allocate_dynamic_stack_space (size, target, known_align)
1024 /* If we're asking for zero bytes, it doesn't matter what we point
1025 to since we can't dereference it. But return a reasonable
1027 if (size == const0_rtx)
1028 return virtual_stack_dynamic_rtx;
1030 /* Otherwise, show we're calling alloca or equivalent. */
1031 current_function_calls_alloca = 1;
1033 /* Ensure the size is in the proper mode. */
1034 if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
1035 size = convert_to_mode (Pmode, size, 1);
1037 /* We will need to ensure that the address we return is aligned to
1038 BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
1039 always know its final value at this point in the compilation (it
1040 might depend on the size of the outgoing parameter lists, for
1041 example), so we must align the value to be returned in that case.
1042 (Note that STACK_DYNAMIC_OFFSET will have a default non-zero value if
1043 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1044 We must also do an alignment operation on the returned value if
1045 the stack pointer alignment is less strict that BIGGEST_ALIGNMENT.
1047 If we have to align, we must leave space in SIZE for the hole
1048 that might result from the alignment operation. */
1050 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET) || ! defined (STACK_BOUNDARY)
1051 #define MUST_ALIGN 1
1053 #define MUST_ALIGN (STACK_BOUNDARY < BIGGEST_ALIGNMENT)
1058 if (GET_CODE (size) == CONST_INT)
1059 size = GEN_INT (INTVAL (size)
1060 + (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1));
1062 size = expand_binop (Pmode, add_optab, size,
1063 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
1064 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1067 #ifdef SETJMP_VIA_SAVE_AREA
1068 /* If setjmp restores regs from a save area in the stack frame,
1069 avoid clobbering the reg save area. Note that the offset of
1070 virtual_incoming_args_rtx includes the preallocated stack args space.
1071 It would be no problem to clobber that, but it's on the wrong side
1072 of the old save area. */
1075 = expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx,
1076 stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN);
1077 size = expand_binop (Pmode, add_optab, size, dynamic_offset,
1078 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1080 #endif /* SETJMP_VIA_SAVE_AREA */
1082 /* Round the size to a multiple of the required stack alignment.
1083 Since the stack if presumed to be rounded before this allocation,
1084 this will maintain the required alignment.
1086 If the stack grows downward, we could save an insn by subtracting
1087 SIZE from the stack pointer and then aligning the stack pointer.
1088 The problem with this is that the stack pointer may be unaligned
1089 between the execution of the subtraction and alignment insns and
1090 some machines do not allow this. Even on those that do, some
1091 signal handlers malfunction if a signal should occur between those
1092 insns. Since this is an extremely rare event, we have no reliable
1093 way of knowing which systems have this problem. So we avoid even
1094 momentarily mis-aligning the stack. */
1096 #ifdef STACK_BOUNDARY
1097 /* If we added a variable amount to SIZE,
1098 we can no longer assume it is aligned. */
1099 #if !defined (SETJMP_VIA_SAVE_AREA)
1100 if (MUST_ALIGN || known_align % STACK_BOUNDARY != 0)
1102 size = round_push (size);
1105 do_pending_stack_adjust ();
1107 /* If needed, check that we have the required amount of stack. Take into
1108 account what has already been checked. */
1109 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
1110 probe_stack_range (STACK_CHECK_MAX_FRAME_SIZE + STACK_CHECK_PROTECT, size);
1112 /* Don't use a TARGET that isn't a pseudo. */
1113 if (target == 0 || GET_CODE (target) != REG
1114 || REGNO (target) < FIRST_PSEUDO_REGISTER)
1115 target = gen_reg_rtx (Pmode);
1117 mark_reg_pointer (target, known_align / BITS_PER_UNIT);
1119 /* Perform the required allocation from the stack. Some systems do
1120 this differently than simply incrementing/decrementing from the
1121 stack pointer, such as acquiring the space by calling malloc(). */
1122 #ifdef HAVE_allocate_stack
1123 if (HAVE_allocate_stack)
1125 enum machine_mode mode;
1127 if (insn_operand_predicate[(int) CODE_FOR_allocate_stack][0]
1128 && ! ((*insn_operand_predicate[(int) CODE_FOR_allocate_stack][0])
1130 target = copy_to_mode_reg (Pmode, target);
1131 mode = insn_operand_mode[(int) CODE_FOR_allocate_stack][1];
1132 size = convert_modes (mode, ptr_mode, size, 1);
1133 if (insn_operand_predicate[(int) CODE_FOR_allocate_stack][1]
1134 && ! ((*insn_operand_predicate[(int) CODE_FOR_allocate_stack][1])
1136 size = copy_to_mode_reg (mode, size);
1138 emit_insn (gen_allocate_stack (target, size));
1143 #ifndef STACK_GROWS_DOWNWARD
1144 emit_move_insn (target, virtual_stack_dynamic_rtx);
1146 size = convert_modes (Pmode, ptr_mode, size, 1);
1147 anti_adjust_stack (size);
1148 #ifdef STACK_GROWS_DOWNWARD
1149 emit_move_insn (target, virtual_stack_dynamic_rtx);
1155 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1156 but we know it can't. So add ourselves and then do
1158 target = expand_binop (Pmode, add_optab, target,
1159 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
1160 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1161 target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target,
1162 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
1164 target = expand_mult (Pmode, target,
1165 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
1169 /* Some systems require a particular insn to refer to the stack
1170 to make the pages exist. */
1173 emit_insn (gen_probe ());
1176 /* Record the new stack level for nonlocal gotos. */
1177 if (nonlocal_goto_handler_slot != 0)
1178 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
1183 /* Emit one stack probe at ADDRESS, an address within the stack. */
1186 emit_stack_probe (address)
1189 rtx memref = gen_rtx_MEM (word_mode, address);
1191 MEM_VOLATILE_P (memref) = 1;
1193 if (STACK_CHECK_PROBE_LOAD)
1194 emit_move_insn (gen_reg_rtx (word_mode), memref);
1196 emit_move_insn (memref, const0_rtx);
1199 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1200 FIRST is a constant and size is a Pmode RTX. These are offsets from the
1201 current stack pointer. STACK_GROWS_DOWNWARD says whether to add or
1202 subtract from the stack. If SIZE is constant, this is done
1203 with a fixed number of probes. Otherwise, we must make a loop. */
1205 #ifdef STACK_GROWS_DOWNWARD
1206 #define STACK_GROW_OP MINUS
1208 #define STACK_GROW_OP PLUS
1212 probe_stack_range (first, size)
1213 HOST_WIDE_INT first;
1216 /* First see if we have an insn to check the stack. Use it if so. */
1217 #ifdef HAVE_check_stack
1218 if (HAVE_check_stack)
1221 = force_operand (gen_rtx_STACK_GROW_OP (Pmode,
1223 plus_constant (size, first)),
1226 if (insn_operand_predicate[(int) CODE_FOR_check_stack][0]
1227 && ! ((*insn_operand_predicate[(int) CODE_FOR_check_stack][0])
1228 (last_address, Pmode)))
1229 last_address = copy_to_mode_reg (Pmode, last_address);
1231 emit_insn (gen_check_stack (last_address));
1236 /* If we have to generate explicit probes, see if we have a constant
1237 small number of them to generate. If so, that's the easy case. */
1238 if (GET_CODE (size) == CONST_INT && INTVAL (size) < 10)
1240 HOST_WIDE_INT offset;
1242 /* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL
1243 for values of N from 1 until it exceeds LAST. If only one
1244 probe is needed, this will not generate any code. Then probe
1246 for (offset = first + STACK_CHECK_PROBE_INTERVAL;
1247 offset < INTVAL (size);
1248 offset = offset + STACK_CHECK_PROBE_INTERVAL)
1249 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1253 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1255 plus_constant (size, first)));
1258 /* In the variable case, do the same as above, but in a loop. We emit loop
1259 notes so that loop optimization can be done. */
1263 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1265 GEN_INT (first + STACK_CHECK_PROBE_INTERVAL)),
1268 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1270 plus_constant (size, first)),
1272 rtx incr = GEN_INT (STACK_CHECK_PROBE_INTERVAL);
1273 rtx loop_lab = gen_label_rtx ();
1274 rtx test_lab = gen_label_rtx ();
1275 rtx end_lab = gen_label_rtx ();
1278 if (GET_CODE (test_addr) != REG
1279 || REGNO (test_addr) < FIRST_PSEUDO_REGISTER)
1280 test_addr = force_reg (Pmode, test_addr);
1282 emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG);
1283 emit_jump (test_lab);
1285 emit_label (loop_lab);
1286 emit_stack_probe (test_addr);
1288 emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT);
1290 #ifdef STACK_GROWS_DOWNWARD
1291 #define CMP_OPCODE GTU
1292 temp = expand_binop (Pmode, sub_optab, test_addr, incr, test_addr,
1295 #define CMP_OPCODE LTU
1296 temp = expand_binop (Pmode, add_optab, test_addr, incr, test_addr,
1300 if (temp != test_addr)
1303 emit_label (test_lab);
1304 emit_cmp_insn (test_addr, last_addr, CMP_OPCODE, NULL_RTX, Pmode, 1, 0);
1305 emit_jump_insn ((*bcc_gen_fctn[(int) CMP_OPCODE]) (loop_lab));
1306 emit_jump (end_lab);
1307 emit_note (NULL_PTR, NOTE_INSN_LOOP_END);
1308 emit_label (end_lab);
1310 /* If will be doing stupid optimization, show test_addr is still live. */
1312 emit_insn (gen_rtx_USE (VOIDmode, test_addr));
1314 emit_stack_probe (last_addr);
1318 /* Return an rtx representing the register or memory location
1319 in which a scalar value of data type VALTYPE
1320 was returned by a function call to function FUNC.
1321 FUNC is a FUNCTION_DECL node if the precise function is known,
1325 hard_function_value (valtype, func)
1329 rtx val = FUNCTION_VALUE (valtype, func);
1330 if (GET_CODE (val) == REG
1331 && GET_MODE (val) == BLKmode)
1333 int bytes = int_size_in_bytes (valtype);
1334 enum machine_mode tmpmode;
1335 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
1336 tmpmode != MAX_MACHINE_MODE;
1337 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
1339 /* Have we found a large enough mode? */
1340 if (GET_MODE_SIZE (tmpmode) >= bytes)
1344 /* No suitable mode found. */
1345 if (tmpmode == MAX_MACHINE_MODE)
1348 PUT_MODE (val, tmpmode);
1353 /* Return an rtx representing the register or memory location
1354 in which a scalar value of mode MODE was returned by a library call. */
1357 hard_libcall_value (mode)
1358 enum machine_mode mode;
1360 return LIBCALL_VALUE (mode);
1363 /* Look up the tree code for a given rtx code
1364 to provide the arithmetic operation for REAL_ARITHMETIC.
1365 The function returns an int because the caller may not know
1366 what `enum tree_code' means. */
1369 rtx_to_tree_code (code)
1372 enum tree_code tcode;
1395 tcode = LAST_AND_UNUSED_TREE_CODE;
1398 return ((int) tcode);