1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987, 91, 94, 95, 96, 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 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 enum machine_mode mode
= GET_MODE (x
);
156 if (GET_CODE (x
) == LO_SUM
)
157 return gen_rtx_LO_SUM (mode
, XEXP (x
, 0),
158 plus_constant_for_output (XEXP (x
, 1), c
));
161 return plus_constant (x
, c
);
164 /* If X is a sum, return a new sum like X but lacking any constant terms.
165 Add all the removed constant terms into *CONSTPTR.
166 X itself is not altered. The result != X if and only if
167 it is not isomorphic to X. */
170 eliminate_constant_term (x
, constptr
)
177 if (GET_CODE (x
) != PLUS
)
180 /* First handle constants appearing at this level explicitly. */
181 if (GET_CODE (XEXP (x
, 1)) == CONST_INT
182 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
184 && GET_CODE (tem
) == CONST_INT
)
187 return eliminate_constant_term (XEXP (x
, 0), constptr
);
191 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
192 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
193 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
194 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
196 && GET_CODE (tem
) == CONST_INT
)
199 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
205 /* Returns the insn that next references REG after INSN, or 0
206 if REG is clobbered before next referenced or we cannot find
207 an insn that references REG in a straight-line piece of code. */
210 find_next_ref (reg
, insn
)
216 for (insn
= NEXT_INSN (insn
); insn
; insn
= next
)
218 next
= NEXT_INSN (insn
);
219 if (GET_CODE (insn
) == NOTE
)
221 if (GET_CODE (insn
) == CODE_LABEL
222 || GET_CODE (insn
) == BARRIER
)
224 if (GET_CODE (insn
) == INSN
225 || GET_CODE (insn
) == JUMP_INSN
226 || GET_CODE (insn
) == CALL_INSN
)
228 if (reg_set_p (reg
, insn
))
230 if (reg_mentioned_p (reg
, PATTERN (insn
)))
232 if (GET_CODE (insn
) == JUMP_INSN
)
234 if (simplejump_p (insn
))
235 next
= JUMP_LABEL (insn
);
239 if (GET_CODE (insn
) == CALL_INSN
240 && REGNO (reg
) < FIRST_PSEUDO_REGISTER
241 && call_used_regs
[REGNO (reg
)])
250 /* Return an rtx for the size in bytes of the value of EXP. */
256 tree size
= size_in_bytes (TREE_TYPE (exp
));
258 if (TREE_CODE (size
) != INTEGER_CST
259 && contains_placeholder_p (size
))
260 size
= build (WITH_RECORD_EXPR
, sizetype
, size
, exp
);
262 return expand_expr (size
, NULL_RTX
, TYPE_MODE (sizetype
),
263 EXPAND_MEMORY_USE_BAD
);
266 /* Return a copy of X in which all memory references
267 and all constants that involve symbol refs
268 have been replaced with new temporary registers.
269 Also emit code to load the memory locations and constants
270 into those registers.
272 If X contains no such constants or memory references,
273 X itself (not a copy) is returned.
275 If a constant is found in the address that is not a legitimate constant
276 in an insn, it is left alone in the hope that it might be valid in the
279 X may contain no arithmetic except addition, subtraction and multiplication.
280 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
283 break_out_memory_refs (x
)
286 if (GET_CODE (x
) == MEM
287 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
288 && GET_MODE (x
) != VOIDmode
))
289 x
= force_reg (GET_MODE (x
), x
);
290 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
291 || GET_CODE (x
) == MULT
)
293 register rtx op0
= break_out_memory_refs (XEXP (x
, 0));
294 register rtx op1
= break_out_memory_refs (XEXP (x
, 1));
296 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
297 x
= gen_rtx_fmt_ee (GET_CODE (x
), Pmode
, op0
, op1
);
303 #ifdef POINTERS_EXTEND_UNSIGNED
305 /* Given X, a memory address in ptr_mode, convert it to an address
306 in Pmode, or vice versa (TO_MODE says which way). We take advantage of
307 the fact that pointers are not allowed to overflow by commuting arithmetic
308 operations over conversions so that address arithmetic insns can be
312 convert_memory_address (to_mode
, x
)
313 enum machine_mode to_mode
;
316 enum machine_mode from_mode
= to_mode
== ptr_mode
? Pmode
: ptr_mode
;
319 /* Here we handle some special cases. If none of them apply, fall through
320 to the default case. */
321 switch (GET_CODE (x
))
328 temp
= gen_rtx_LABEL_REF (to_mode
, XEXP (x
, 0));
329 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
333 temp
= gen_rtx_SYMBOL_REF (to_mode
, XSTR (x
, 0));
334 SYMBOL_REF_FLAG (temp
) = SYMBOL_REF_FLAG (x
);
335 CONSTANT_POOL_ADDRESS_P (temp
) = CONSTANT_POOL_ADDRESS_P (x
);
339 return gen_rtx_CONST (to_mode
,
340 convert_memory_address (to_mode
, XEXP (x
, 0)));
344 /* For addition the second operand is a small constant, we can safely
345 permute the conversion and addition operation. We can always safely
346 permute them if we are making the address narrower. In addition,
347 always permute the operations if this is a constant. */
348 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
349 || (GET_CODE (x
) == PLUS
&& GET_CODE (XEXP (x
, 1)) == CONST_INT
350 && (INTVAL (XEXP (x
, 1)) + 20000 < 40000
351 || CONSTANT_P (XEXP (x
, 0)))))
352 return gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
353 convert_memory_address (to_mode
, XEXP (x
, 0)),
354 convert_memory_address (to_mode
, XEXP (x
, 1)));
361 return convert_modes (to_mode
, from_mode
,
362 x
, POINTERS_EXTEND_UNSIGNED
);
366 /* Given a memory address or facsimile X, construct a new address,
367 currently equivalent, that is stable: future stores won't change it.
369 X must be composed of constants, register and memory references
370 combined with addition, subtraction and multiplication:
371 in other words, just what you can get from expand_expr if sum_ok is 1.
373 Works by making copies of all regs and memory locations used
374 by X and combining them the same way X does.
375 You could also stabilize the reference to this address
376 by copying the address to a register with copy_to_reg;
377 but then you wouldn't get indexed addressing in the reference. */
383 if (GET_CODE (x
) == REG
)
385 if (REGNO (x
) != FRAME_POINTER_REGNUM
386 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
387 && REGNO (x
) != HARD_FRAME_POINTER_REGNUM
392 else if (GET_CODE (x
) == MEM
)
394 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
395 || GET_CODE (x
) == MULT
)
397 register rtx op0
= copy_all_regs (XEXP (x
, 0));
398 register rtx op1
= copy_all_regs (XEXP (x
, 1));
399 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
400 x
= gen_rtx_fmt_ee (GET_CODE (x
), Pmode
, op0
, op1
);
405 /* Return something equivalent to X but valid as a memory address
406 for something of mode MODE. When X is not itself valid, this
407 works by copying X or subexpressions of it into registers. */
410 memory_address (mode
, x
)
411 enum machine_mode mode
;
414 register rtx oldx
= x
;
416 if (GET_CODE (x
) == ADDRESSOF
)
419 #ifdef POINTERS_EXTEND_UNSIGNED
420 if (GET_MODE (x
) == ptr_mode
)
421 x
= convert_memory_address (Pmode
, x
);
424 /* By passing constant addresses thru registers
425 we get a chance to cse them. */
426 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
427 x
= force_reg (Pmode
, x
);
429 /* Accept a QUEUED that refers to a REG
430 even though that isn't a valid address.
431 On attempting to put this in an insn we will call protect_from_queue
432 which will turn it into a REG, which is valid. */
433 else if (GET_CODE (x
) == QUEUED
434 && GET_CODE (QUEUED_VAR (x
)) == REG
)
437 /* We get better cse by rejecting indirect addressing at this stage.
438 Let the combiner create indirect addresses where appropriate.
439 For now, generate the code so that the subexpressions useful to share
440 are visible. But not if cse won't be done! */
443 if (! cse_not_expected
&& GET_CODE (x
) != REG
)
444 x
= break_out_memory_refs (x
);
446 /* At this point, any valid address is accepted. */
447 GO_IF_LEGITIMATE_ADDRESS (mode
, x
, win
);
449 /* If it was valid before but breaking out memory refs invalidated it,
450 use it the old way. */
451 if (memory_address_p (mode
, oldx
))
454 /* Perform machine-dependent transformations on X
455 in certain cases. This is not necessary since the code
456 below can handle all possible cases, but machine-dependent
457 transformations can make better code. */
458 LEGITIMIZE_ADDRESS (x
, oldx
, mode
, win
);
460 /* PLUS and MULT can appear in special ways
461 as the result of attempts to make an address usable for indexing.
462 Usually they are dealt with by calling force_operand, below.
463 But a sum containing constant terms is special
464 if removing them makes the sum a valid address:
465 then we generate that address in a register
466 and index off of it. We do this because it often makes
467 shorter code, and because the addresses thus generated
468 in registers often become common subexpressions. */
469 if (GET_CODE (x
) == PLUS
)
471 rtx constant_term
= const0_rtx
;
472 rtx y
= eliminate_constant_term (x
, &constant_term
);
473 if (constant_term
== const0_rtx
474 || ! memory_address_p (mode
, y
))
475 x
= force_operand (x
, NULL_RTX
);
478 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
479 if (! memory_address_p (mode
, y
))
480 x
= force_operand (x
, NULL_RTX
);
486 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
487 x
= force_operand (x
, NULL_RTX
);
489 /* If we have a register that's an invalid address,
490 it must be a hard reg of the wrong class. Copy it to a pseudo. */
491 else if (GET_CODE (x
) == REG
)
494 /* Last resort: copy the value to a register, since
495 the register is a valid address. */
497 x
= force_reg (Pmode
, x
);
504 if (flag_force_addr
&& ! cse_not_expected
&& GET_CODE (x
) != REG
505 /* Don't copy an addr via a reg if it is one of our stack slots. */
506 && ! (GET_CODE (x
) == PLUS
507 && (XEXP (x
, 0) == virtual_stack_vars_rtx
508 || XEXP (x
, 0) == virtual_incoming_args_rtx
)))
510 if (general_operand (x
, Pmode
))
511 x
= force_reg (Pmode
, x
);
513 x
= force_operand (x
, NULL_RTX
);
519 /* If we didn't change the address, we are done. Otherwise, mark
520 a reg as a pointer if we have REG or REG + CONST_INT. */
523 else if (GET_CODE (x
) == REG
)
524 mark_reg_pointer (x
, 1);
525 else if (GET_CODE (x
) == PLUS
526 && GET_CODE (XEXP (x
, 0)) == REG
527 && GET_CODE (XEXP (x
, 1)) == CONST_INT
)
528 mark_reg_pointer (XEXP (x
, 0), 1);
530 /* OLDX may have been the address on a temporary. Update the address
531 to indicate that X is now used. */
532 update_temp_slot_address (oldx
, x
);
537 /* Like `memory_address' but pretend `flag_force_addr' is 0. */
540 memory_address_noforce (mode
, x
)
541 enum machine_mode mode
;
544 int ambient_force_addr
= flag_force_addr
;
548 val
= memory_address (mode
, x
);
549 flag_force_addr
= ambient_force_addr
;
553 /* Convert a mem ref into one with a valid memory address.
554 Pass through anything else unchanged. */
560 if (GET_CODE (ref
) != MEM
)
562 if (memory_address_p (GET_MODE (ref
), XEXP (ref
, 0)))
564 /* Don't alter REF itself, since that is probably a stack slot. */
565 return change_address (ref
, GET_MODE (ref
), XEXP (ref
, 0));
568 /* Return a modified copy of X with its memory address copied
569 into a temporary register to protect it from side effects.
570 If X is not a MEM, it is returned unchanged (and not copied).
571 Perhaps even if it is a MEM, if there is no need to change it. */
578 if (GET_CODE (x
) != MEM
)
581 if (rtx_unstable_p (addr
))
583 rtx temp
= copy_all_regs (addr
);
585 if (GET_CODE (temp
) != REG
)
586 temp
= copy_to_reg (temp
);
587 mem
= gen_rtx_MEM (GET_MODE (x
), temp
);
589 /* Mark returned memref with in_struct if it's in an array or
590 structure. Copy const and volatile from original memref. */
592 MEM_IN_STRUCT_P (mem
) = MEM_IN_STRUCT_P (x
) || GET_CODE (addr
) == PLUS
;
593 RTX_UNCHANGING_P (mem
) = RTX_UNCHANGING_P (x
);
594 MEM_VOLATILE_P (mem
) = MEM_VOLATILE_P (x
);
600 /* Copy the value or contents of X to a new temp reg and return that reg. */
606 register rtx temp
= gen_reg_rtx (GET_MODE (x
));
608 /* If not an operand, must be an address with PLUS and MULT so
609 do the computation. */
610 if (! general_operand (x
, VOIDmode
))
611 x
= force_operand (x
, temp
);
614 emit_move_insn (temp
, x
);
619 /* Like copy_to_reg but always give the new register mode Pmode
620 in case X is a constant. */
626 return copy_to_mode_reg (Pmode
, x
);
629 /* Like copy_to_reg but always give the new register mode MODE
630 in case X is a constant. */
633 copy_to_mode_reg (mode
, x
)
634 enum machine_mode mode
;
637 register rtx temp
= gen_reg_rtx (mode
);
639 /* If not an operand, must be an address with PLUS and MULT so
640 do the computation. */
641 if (! general_operand (x
, VOIDmode
))
642 x
= force_operand (x
, temp
);
644 if (GET_MODE (x
) != mode
&& GET_MODE (x
) != VOIDmode
)
647 emit_move_insn (temp
, x
);
651 /* Load X into a register if it is not already one.
652 Use mode MODE for the register.
653 X should be valid for mode MODE, but it may be a constant which
654 is valid for all integer modes; that's why caller must specify MODE.
656 The caller must not alter the value in the register we return,
657 since we mark it as a "constant" register. */
661 enum machine_mode mode
;
664 register rtx temp
, insn
, set
;
666 if (GET_CODE (x
) == REG
)
668 temp
= gen_reg_rtx (mode
);
669 insn
= emit_move_insn (temp
, x
);
671 /* Let optimizers know that TEMP's value never changes
672 and that X can be substituted for it. Don't get confused
673 if INSN set something else (such as a SUBREG of TEMP). */
675 && (set
= single_set (insn
)) != 0
676 && SET_DEST (set
) == temp
)
678 rtx note
= find_reg_note (insn
, REG_EQUAL
, NULL_RTX
);
683 REG_NOTES (insn
) = gen_rtx_EXPR_LIST (REG_EQUAL
, x
, REG_NOTES (insn
));
688 /* If X is a memory ref, copy its contents to a new temp reg and return
689 that reg. Otherwise, return X. */
696 if (GET_CODE (x
) != MEM
|| GET_MODE (x
) == BLKmode
)
698 temp
= gen_reg_rtx (GET_MODE (x
));
699 emit_move_insn (temp
, x
);
703 /* Copy X to TARGET (if it's nonzero and a reg)
704 or to a new temp reg and return that reg.
705 MODE is the mode to use for X in case it is a constant. */
708 copy_to_suggested_reg (x
, target
, mode
)
710 enum machine_mode mode
;
714 if (target
&& GET_CODE (target
) == REG
)
717 temp
= gen_reg_rtx (mode
);
719 emit_move_insn (temp
, x
);
723 /* Return the mode to use to store a scalar of TYPE and MODE.
724 PUNSIGNEDP points to the signedness of the type and may be adjusted
725 to show what signedness to use on extension operations.
727 FOR_CALL is non-zero if this call is promoting args for a call. */
730 promote_mode (type
, mode
, punsignedp
, for_call
)
732 enum machine_mode mode
;
736 enum tree_code code
= TREE_CODE (type
);
737 int unsignedp
= *punsignedp
;
739 #ifdef PROMOTE_FOR_CALL_ONLY
747 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
748 case CHAR_TYPE
: case REAL_TYPE
: case OFFSET_TYPE
:
749 PROMOTE_MODE (mode
, unsignedp
, type
);
753 #ifdef POINTERS_EXTEND_UNSIGNED
757 unsignedp
= POINTERS_EXTEND_UNSIGNED
;
765 *punsignedp
= unsignedp
;
769 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
770 This pops when ADJUST is positive. ADJUST need not be constant. */
773 adjust_stack (adjust
)
777 adjust
= protect_from_queue (adjust
, 0);
779 if (adjust
== const0_rtx
)
782 temp
= expand_binop (Pmode
,
783 #ifdef STACK_GROWS_DOWNWARD
788 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
791 if (temp
!= stack_pointer_rtx
)
792 emit_move_insn (stack_pointer_rtx
, temp
);
795 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
796 This pushes when ADJUST is positive. ADJUST need not be constant. */
799 anti_adjust_stack (adjust
)
803 adjust
= protect_from_queue (adjust
, 0);
805 if (adjust
== const0_rtx
)
808 temp
= expand_binop (Pmode
,
809 #ifdef STACK_GROWS_DOWNWARD
814 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
817 if (temp
!= stack_pointer_rtx
)
818 emit_move_insn (stack_pointer_rtx
, temp
);
821 /* Round the size of a block to be pushed up to the boundary required
822 by this machine. SIZE is the desired size, which need not be constant. */
828 #ifdef STACK_BOUNDARY
829 int align
= STACK_BOUNDARY
/ BITS_PER_UNIT
;
832 if (GET_CODE (size
) == CONST_INT
)
834 int new = (INTVAL (size
) + align
- 1) / align
* align
;
835 if (INTVAL (size
) != new)
836 size
= GEN_INT (new);
840 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
841 but we know it can't. So add ourselves and then do
843 size
= expand_binop (Pmode
, add_optab
, size
, GEN_INT (align
- 1),
844 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
845 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, GEN_INT (align
),
847 size
= expand_mult (Pmode
, size
, GEN_INT (align
), NULL_RTX
, 1);
849 #endif /* STACK_BOUNDARY */
853 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
854 to a previously-created save area. If no save area has been allocated,
855 this function will allocate one. If a save area is specified, it
856 must be of the proper mode.
858 The insns are emitted after insn AFTER, if nonzero, otherwise the insns
859 are emitted at the current position. */
862 emit_stack_save (save_level
, psave
, after
)
863 enum save_level save_level
;
868 /* The default is that we use a move insn and save in a Pmode object. */
869 rtx (*fcn
) () = gen_move_insn
;
870 enum machine_mode mode
= Pmode
;
872 /* See if this machine has anything special to do for this kind of save. */
875 #ifdef HAVE_save_stack_block
877 if (HAVE_save_stack_block
)
879 fcn
= gen_save_stack_block
;
880 mode
= insn_operand_mode
[CODE_FOR_save_stack_block
][0];
884 #ifdef HAVE_save_stack_function
886 if (HAVE_save_stack_function
)
888 fcn
= gen_save_stack_function
;
889 mode
= insn_operand_mode
[CODE_FOR_save_stack_function
][0];
893 #ifdef HAVE_save_stack_nonlocal
895 if (HAVE_save_stack_nonlocal
)
897 fcn
= gen_save_stack_nonlocal
;
898 mode
= insn_operand_mode
[(int) CODE_FOR_save_stack_nonlocal
][0];
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
) () = 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
980 if (HAVE_restore_stack_nonlocal
)
981 fcn
= gen_restore_stack_nonlocal
;
989 sa
= validize_mem (sa
);
996 emit_insn (fcn (stack_pointer_rtx
, sa
));
997 seq
= gen_sequence ();
999 emit_insn_after (seq
, after
);
1002 emit_insn (fcn (stack_pointer_rtx
, sa
));
1005 #ifdef SETJMP_VIA_SAVE_AREA
1006 /* Optimize RTL generated by allocate_dynamic_stack_space for targets
1007 where SETJMP_VIA_SAVE_AREA is true. The problem is that on these
1008 platforms, the dynamic stack space used can corrupt the original
1009 frame, thus causing a crash if a longjmp unwinds to it. */
1012 optimize_save_area_alloca (insns
)
1017 for (insn
= insns
; insn
; insn
= NEXT_INSN(insn
))
1021 if (GET_CODE (insn
) != INSN
)
1024 for (note
= REG_NOTES (insn
); note
; note
= XEXP (note
, 1))
1026 if (REG_NOTE_KIND (note
) != REG_SAVE_AREA
)
1029 if (!current_function_calls_setjmp
)
1031 rtx pat
= PATTERN (insn
);
1033 /* If we do not see the note in a pattern matching
1034 these precise characteristics, we did something
1035 entirely wrong in allocate_dynamic_stack_space.
1037 Note, one way this could happen if if SETJMP_VIA_SAVE_AREA
1038 was defined on a machine where stacks grow towards higher
1041 Right now only supported port with stack that grow upward
1042 is the HPPA and it does not define SETJMP_VIA_SAVE_AREA. */
1043 if (GET_CODE (pat
) != SET
1044 || SET_DEST (pat
) != stack_pointer_rtx
1045 || GET_CODE (SET_SRC (pat
)) != MINUS
1046 || XEXP (SET_SRC (pat
), 0) != stack_pointer_rtx
)
1049 /* This will now be transformed into a (set REG REG)
1050 so we can just blow away all the other notes. */
1051 XEXP (SET_SRC (pat
), 1) = XEXP (note
, 0);
1052 REG_NOTES (insn
) = NULL_RTX
;
1056 /* setjmp was called, we must remove the REG_SAVE_AREA
1057 note so that later passes do not get confused by its
1059 if (note
== REG_NOTES (insn
))
1061 REG_NOTES (insn
) = XEXP (note
, 1);
1067 for (srch
= REG_NOTES (insn
); srch
; srch
= XEXP (srch
, 1))
1068 if (XEXP (srch
, 1) == note
)
1071 if (srch
== NULL_RTX
)
1074 XEXP (srch
, 1) = XEXP (note
, 1);
1077 /* Once we've seen the note of interest, we need not look at
1078 the rest of them. */
1083 #endif /* SETJMP_VIA_SAVE_AREA */
1085 /* Return an rtx representing the address of an area of memory dynamically
1086 pushed on the stack. This region of memory is always aligned to
1087 a multiple of BIGGEST_ALIGNMENT.
1089 Any required stack pointer alignment is preserved.
1091 SIZE is an rtx representing the size of the area.
1092 TARGET is a place in which the address can be placed.
1094 KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */
1097 allocate_dynamic_stack_space (size
, target
, known_align
)
1102 #ifdef SETJMP_VIA_SAVE_AREA
1103 rtx setjmpless_size
= NULL_RTX
;
1106 /* If we're asking for zero bytes, it doesn't matter what we point
1107 to since we can't dereference it. But return a reasonable
1109 if (size
== const0_rtx
)
1110 return virtual_stack_dynamic_rtx
;
1112 /* Otherwise, show we're calling alloca or equivalent. */
1113 current_function_calls_alloca
= 1;
1115 /* Ensure the size is in the proper mode. */
1116 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1117 size
= convert_to_mode (Pmode
, size
, 1);
1119 /* We will need to ensure that the address we return is aligned to
1120 BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
1121 always know its final value at this point in the compilation (it
1122 might depend on the size of the outgoing parameter lists, for
1123 example), so we must align the value to be returned in that case.
1124 (Note that STACK_DYNAMIC_OFFSET will have a default non-zero value if
1125 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1126 We must also do an alignment operation on the returned value if
1127 the stack pointer alignment is less strict that BIGGEST_ALIGNMENT.
1129 If we have to align, we must leave space in SIZE for the hole
1130 that might result from the alignment operation. */
1132 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET) || ! defined (STACK_BOUNDARY)
1133 #define MUST_ALIGN 1
1135 #define MUST_ALIGN (STACK_BOUNDARY < BIGGEST_ALIGNMENT)
1140 if (GET_CODE (size
) == CONST_INT
)
1141 size
= GEN_INT (INTVAL (size
)
1142 + (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1));
1144 size
= expand_binop (Pmode
, add_optab
, size
,
1145 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1),
1146 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1149 #ifdef SETJMP_VIA_SAVE_AREA
1150 /* If setjmp restores regs from a save area in the stack frame,
1151 avoid clobbering the reg save area. Note that the offset of
1152 virtual_incoming_args_rtx includes the preallocated stack args space.
1153 It would be no problem to clobber that, but it's on the wrong side
1154 of the old save area. */
1157 = expand_binop (Pmode
, sub_optab
, virtual_stack_dynamic_rtx
,
1158 stack_pointer_rtx
, NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1160 if (!current_function_calls_setjmp
)
1162 int align
= STACK_BOUNDARY
/ BITS_PER_UNIT
;
1164 /* See optimize_save_area_alloca to understand what is being
1167 #if !defined(STACK_BOUNDARY) || !defined(MUST_ALIGN) || (STACK_BOUNDARY != BIGGEST_ALIGNMENT)
1168 /* If anyone creates a target with these characteristics, let them
1169 know that our optimization cannot work correctly in such a case. */
1173 if (GET_CODE (size
) == CONST_INT
)
1175 int new = INTVAL (size
) / align
* align
;
1177 if (INTVAL (size
) != new)
1178 setjmpless_size
= GEN_INT (new);
1180 setjmpless_size
= size
;
1184 /* Since we know overflow is not possible, we avoid using
1185 CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */
1186 setjmpless_size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
,
1187 GEN_INT (align
), NULL_RTX
, 1);
1188 setjmpless_size
= expand_mult (Pmode
, setjmpless_size
,
1189 GEN_INT (align
), NULL_RTX
, 1);
1191 /* Our optimization works based upon being able to perform a simple
1192 transformation of this RTL into a (set REG REG) so make sure things
1193 did in fact end up in a REG. */
1194 if (!arith_operand (setjmpless_size
, Pmode
))
1195 setjmpless_size
= force_reg (Pmode
, setjmpless_size
);
1198 size
= expand_binop (Pmode
, add_optab
, size
, dynamic_offset
,
1199 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1201 #endif /* SETJMP_VIA_SAVE_AREA */
1203 /* Round the size to a multiple of the required stack alignment.
1204 Since the stack if presumed to be rounded before this allocation,
1205 this will maintain the required alignment.
1207 If the stack grows downward, we could save an insn by subtracting
1208 SIZE from the stack pointer and then aligning the stack pointer.
1209 The problem with this is that the stack pointer may be unaligned
1210 between the execution of the subtraction and alignment insns and
1211 some machines do not allow this. Even on those that do, some
1212 signal handlers malfunction if a signal should occur between those
1213 insns. Since this is an extremely rare event, we have no reliable
1214 way of knowing which systems have this problem. So we avoid even
1215 momentarily mis-aligning the stack. */
1217 #ifdef STACK_BOUNDARY
1218 /* If we added a variable amount to SIZE,
1219 we can no longer assume it is aligned. */
1220 #if !defined (SETJMP_VIA_SAVE_AREA)
1221 if (MUST_ALIGN
|| known_align
% STACK_BOUNDARY
!= 0)
1223 size
= round_push (size
);
1226 do_pending_stack_adjust ();
1228 /* If needed, check that we have the required amount of stack. Take into
1229 account what has already been checked. */
1230 if (flag_stack_check
&& ! STACK_CHECK_BUILTIN
)
1231 probe_stack_range (STACK_CHECK_MAX_FRAME_SIZE
+ STACK_CHECK_PROTECT
, size
);
1233 /* Don't use a TARGET that isn't a pseudo. */
1234 if (target
== 0 || GET_CODE (target
) != REG
1235 || REGNO (target
) < FIRST_PSEUDO_REGISTER
)
1236 target
= gen_reg_rtx (Pmode
);
1238 mark_reg_pointer (target
, known_align
/ BITS_PER_UNIT
);
1240 /* Perform the required allocation from the stack. Some systems do
1241 this differently than simply incrementing/decrementing from the
1242 stack pointer, such as acquiring the space by calling malloc(). */
1243 #ifdef HAVE_allocate_stack
1244 if (HAVE_allocate_stack
)
1246 enum machine_mode mode
;
1248 if (insn_operand_predicate
[(int) CODE_FOR_allocate_stack
][0]
1249 && ! ((*insn_operand_predicate
[(int) CODE_FOR_allocate_stack
][0])
1251 target
= copy_to_mode_reg (Pmode
, target
);
1252 mode
= insn_operand_mode
[(int) CODE_FOR_allocate_stack
][1];
1253 size
= convert_modes (mode
, ptr_mode
, size
, 1);
1254 if (insn_operand_predicate
[(int) CODE_FOR_allocate_stack
][1]
1255 && ! ((*insn_operand_predicate
[(int) CODE_FOR_allocate_stack
][1])
1257 size
= copy_to_mode_reg (mode
, size
);
1259 emit_insn (gen_allocate_stack (target
, size
));
1264 #ifndef STACK_GROWS_DOWNWARD
1265 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1267 size
= convert_modes (Pmode
, ptr_mode
, size
, 1);
1268 anti_adjust_stack (size
);
1269 #ifdef SETJMP_VIA_SAVE_AREA
1270 if (setjmpless_size
!= NULL_RTX
)
1272 rtx note_target
= get_last_insn ();
1274 REG_NOTES (note_target
) = gen_rtx (EXPR_LIST
, REG_SAVE_AREA
,
1276 REG_NOTES (note_target
));
1278 #endif /* SETJMP_VIA_SAVE_AREA */
1279 #ifdef STACK_GROWS_DOWNWARD
1280 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1286 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1287 but we know it can't. So add ourselves and then do
1289 target
= expand_binop (Pmode
, add_optab
, target
,
1290 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1),
1291 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1292 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1293 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
),
1295 target
= expand_mult (Pmode
, target
,
1296 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
),
1300 /* Some systems require a particular insn to refer to the stack
1301 to make the pages exist. */
1304 emit_insn (gen_probe ());
1307 /* Record the new stack level for nonlocal gotos. */
1308 if (nonlocal_goto_handler_slot
!= 0)
1309 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
, NULL_RTX
);
1314 /* Emit one stack probe at ADDRESS, an address within the stack. */
1317 emit_stack_probe (address
)
1320 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1322 MEM_VOLATILE_P (memref
) = 1;
1324 if (STACK_CHECK_PROBE_LOAD
)
1325 emit_move_insn (gen_reg_rtx (word_mode
), memref
);
1327 emit_move_insn (memref
, const0_rtx
);
1330 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1331 FIRST is a constant and size is a Pmode RTX. These are offsets from the
1332 current stack pointer. STACK_GROWS_DOWNWARD says whether to add or
1333 subtract from the stack. If SIZE is constant, this is done
1334 with a fixed number of probes. Otherwise, we must make a loop. */
1336 #ifdef STACK_GROWS_DOWNWARD
1337 #define STACK_GROW_OP MINUS
1339 #define STACK_GROW_OP PLUS
1343 probe_stack_range (first
, size
)
1344 HOST_WIDE_INT first
;
1347 /* First see if we have an insn to check the stack. Use it if so. */
1348 #ifdef HAVE_check_stack
1349 if (HAVE_check_stack
)
1352 = force_operand (gen_rtx_STACK_GROW_OP (Pmode
,
1354 plus_constant (size
, first
)),
1357 if (insn_operand_predicate
[(int) CODE_FOR_check_stack
][0]
1358 && ! ((*insn_operand_predicate
[(int) CODE_FOR_check_stack
][0])
1359 (last_address
, Pmode
)))
1360 last_address
= copy_to_mode_reg (Pmode
, last_address
);
1362 emit_insn (gen_check_stack (last_address
));
1367 /* If we have to generate explicit probes, see if we have a constant
1368 small number of them to generate. If so, that's the easy case. */
1369 if (GET_CODE (size
) == CONST_INT
&& INTVAL (size
) < 10)
1371 HOST_WIDE_INT offset
;
1373 /* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL
1374 for values of N from 1 until it exceeds LAST. If only one
1375 probe is needed, this will not generate any code. Then probe
1377 for (offset
= first
+ STACK_CHECK_PROBE_INTERVAL
;
1378 offset
< INTVAL (size
);
1379 offset
= offset
+ STACK_CHECK_PROBE_INTERVAL
)
1380 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1384 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1386 plus_constant (size
, first
)));
1389 /* In the variable case, do the same as above, but in a loop. We emit loop
1390 notes so that loop optimization can be done. */
1394 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1396 GEN_INT (first
+ STACK_CHECK_PROBE_INTERVAL
)),
1399 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1401 plus_constant (size
, first
)),
1403 rtx incr
= GEN_INT (STACK_CHECK_PROBE_INTERVAL
);
1404 rtx loop_lab
= gen_label_rtx ();
1405 rtx test_lab
= gen_label_rtx ();
1406 rtx end_lab
= gen_label_rtx ();
1409 if (GET_CODE (test_addr
) != REG
1410 || REGNO (test_addr
) < FIRST_PSEUDO_REGISTER
)
1411 test_addr
= force_reg (Pmode
, test_addr
);
1413 emit_note (NULL_PTR
, NOTE_INSN_LOOP_BEG
);
1414 emit_jump (test_lab
);
1416 emit_label (loop_lab
);
1417 emit_stack_probe (test_addr
);
1419 emit_note (NULL_PTR
, NOTE_INSN_LOOP_CONT
);
1421 #ifdef STACK_GROWS_DOWNWARD
1422 #define CMP_OPCODE GTU
1423 temp
= expand_binop (Pmode
, sub_optab
, test_addr
, incr
, test_addr
,
1426 #define CMP_OPCODE LTU
1427 temp
= expand_binop (Pmode
, add_optab
, test_addr
, incr
, test_addr
,
1431 if (temp
!= test_addr
)
1434 emit_label (test_lab
);
1435 emit_cmp_insn (test_addr
, last_addr
, CMP_OPCODE
, NULL_RTX
, Pmode
, 1, 0);
1436 emit_jump_insn ((*bcc_gen_fctn
[(int) CMP_OPCODE
]) (loop_lab
));
1437 emit_jump (end_lab
);
1438 emit_note (NULL_PTR
, NOTE_INSN_LOOP_END
);
1439 emit_label (end_lab
);
1441 /* If will be doing stupid optimization, show test_addr is still live. */
1443 emit_insn (gen_rtx_USE (VOIDmode
, test_addr
));
1445 emit_stack_probe (last_addr
);
1449 /* Return an rtx representing the register or memory location
1450 in which a scalar value of data type VALTYPE
1451 was returned by a function call to function FUNC.
1452 FUNC is a FUNCTION_DECL node if the precise function is known,
1456 hard_function_value (valtype
, func
)
1460 rtx val
= FUNCTION_VALUE (valtype
, func
);
1461 if (GET_CODE (val
) == REG
1462 && GET_MODE (val
) == BLKmode
)
1464 int bytes
= int_size_in_bytes (valtype
);
1465 enum machine_mode tmpmode
;
1466 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1467 tmpmode
!= MAX_MACHINE_MODE
;
1468 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1470 /* Have we found a large enough mode? */
1471 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1475 /* No suitable mode found. */
1476 if (tmpmode
== MAX_MACHINE_MODE
)
1479 PUT_MODE (val
, tmpmode
);
1484 /* Return an rtx representing the register or memory location
1485 in which a scalar value of mode MODE was returned by a library call. */
1488 hard_libcall_value (mode
)
1489 enum machine_mode mode
;
1491 return LIBCALL_VALUE (mode
);
1494 /* Look up the tree code for a given rtx code
1495 to provide the arithmetic operation for REAL_ARITHMETIC.
1496 The function returns an int because the caller may not know
1497 what `enum tree_code' means. */
1500 rtx_to_tree_code (code
)
1503 enum tree_code tcode
;
1526 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1529 return ((int) tcode
);