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
);
157 if (GET_CODE (x
) == LO_SUM
)
158 return gen_rtx_LO_SUM (mode
, XEXP (x
, 0),
159 plus_constant_for_output (XEXP (x
, 1), c
));
162 return plus_constant (x
, c
);
165 /* If X is a sum, return a new sum like X but lacking any constant terms.
166 Add all the removed constant terms into *CONSTPTR.
167 X itself is not altered. The result != X if and only if
168 it is not isomorphic to X. */
171 eliminate_constant_term (x
, constptr
)
178 if (GET_CODE (x
) != PLUS
)
181 /* First handle constants appearing at this level explicitly. */
182 if (GET_CODE (XEXP (x
, 1)) == CONST_INT
183 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
185 && GET_CODE (tem
) == CONST_INT
)
188 return eliminate_constant_term (XEXP (x
, 0), constptr
);
192 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
193 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
194 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
195 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
197 && GET_CODE (tem
) == CONST_INT
)
200 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
206 /* Returns the insn that next references REG after INSN, or 0
207 if REG is clobbered before next referenced or we cannot find
208 an insn that references REG in a straight-line piece of code. */
211 find_next_ref (reg
, insn
)
217 for (insn
= NEXT_INSN (insn
); insn
; insn
= next
)
219 next
= NEXT_INSN (insn
);
220 if (GET_CODE (insn
) == NOTE
)
222 if (GET_CODE (insn
) == CODE_LABEL
223 || GET_CODE (insn
) == BARRIER
)
225 if (GET_CODE (insn
) == INSN
226 || GET_CODE (insn
) == JUMP_INSN
227 || GET_CODE (insn
) == CALL_INSN
)
229 if (reg_set_p (reg
, insn
))
231 if (reg_mentioned_p (reg
, PATTERN (insn
)))
233 if (GET_CODE (insn
) == JUMP_INSN
)
235 if (simplejump_p (insn
))
236 next
= JUMP_LABEL (insn
);
240 if (GET_CODE (insn
) == CALL_INSN
241 && REGNO (reg
) < FIRST_PSEUDO_REGISTER
242 && call_used_regs
[REGNO (reg
)])
251 /* Return an rtx for the size in bytes of the value of EXP. */
257 tree size
= size_in_bytes (TREE_TYPE (exp
));
259 if (TREE_CODE (size
) != INTEGER_CST
260 && contains_placeholder_p (size
))
261 size
= build (WITH_RECORD_EXPR
, sizetype
, size
, exp
);
263 return expand_expr (size
, NULL_RTX
, TYPE_MODE (sizetype
),
264 EXPAND_MEMORY_USE_BAD
);
267 /* Return a copy of X in which all memory references
268 and all constants that involve symbol refs
269 have been replaced with new temporary registers.
270 Also emit code to load the memory locations and constants
271 into those registers.
273 If X contains no such constants or memory references,
274 X itself (not a copy) is returned.
276 If a constant is found in the address that is not a legitimate constant
277 in an insn, it is left alone in the hope that it might be valid in the
280 X may contain no arithmetic except addition, subtraction and multiplication.
281 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
284 break_out_memory_refs (x
)
287 if (GET_CODE (x
) == MEM
288 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
289 && GET_MODE (x
) != VOIDmode
))
290 x
= force_reg (GET_MODE (x
), x
);
291 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
292 || GET_CODE (x
) == MULT
)
294 register rtx op0
= break_out_memory_refs (XEXP (x
, 0));
295 register rtx op1
= break_out_memory_refs (XEXP (x
, 1));
297 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
298 x
= gen_rtx_fmt_ee (GET_CODE (x
), Pmode
, op0
, op1
);
304 #ifdef POINTERS_EXTEND_UNSIGNED
306 /* Given X, a memory address in ptr_mode, convert it to an address
307 in Pmode, or vice versa (TO_MODE says which way). We take advantage of
308 the fact that pointers are not allowed to overflow by commuting arithmetic
309 operations over conversions so that address arithmetic insns can be
313 convert_memory_address (to_mode
, x
)
314 enum machine_mode to_mode
;
317 enum machine_mode from_mode
= to_mode
== ptr_mode
? Pmode
: ptr_mode
;
320 /* Here we handle some special cases. If none of them apply, fall through
321 to the default case. */
322 switch (GET_CODE (x
))
329 temp
= gen_rtx_LABEL_REF (to_mode
, XEXP (x
, 0));
330 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
334 temp
= gen_rtx_SYMBOL_REF (to_mode
, XSTR (x
, 0));
335 SYMBOL_REF_FLAG (temp
) = SYMBOL_REF_FLAG (x
);
336 CONSTANT_POOL_ADDRESS_P (temp
) = CONSTANT_POOL_ADDRESS_P (x
);
340 return gen_rtx_CONST (to_mode
,
341 convert_memory_address (to_mode
, XEXP (x
, 0)));
345 /* For addition the second operand is a small constant, we can safely
346 permute the conversion and addition operation. We can always safely
347 permute them if we are making the address narrower. In addition,
348 always permute the operations if this is a constant. */
349 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
350 || (GET_CODE (x
) == PLUS
&& GET_CODE (XEXP (x
, 1)) == CONST_INT
351 && (INTVAL (XEXP (x
, 1)) + 20000 < 40000
352 || CONSTANT_P (XEXP (x
, 0)))))
353 return gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
354 convert_memory_address (to_mode
, XEXP (x
, 0)),
355 convert_memory_address (to_mode
, XEXP (x
, 1)));
362 return convert_modes (to_mode
, from_mode
,
363 x
, POINTERS_EXTEND_UNSIGNED
);
367 /* Given a memory address or facsimile X, construct a new address,
368 currently equivalent, that is stable: future stores won't change it.
370 X must be composed of constants, register and memory references
371 combined with addition, subtraction and multiplication:
372 in other words, just what you can get from expand_expr if sum_ok is 1.
374 Works by making copies of all regs and memory locations used
375 by X and combining them the same way X does.
376 You could also stabilize the reference to this address
377 by copying the address to a register with copy_to_reg;
378 but then you wouldn't get indexed addressing in the reference. */
384 if (GET_CODE (x
) == REG
)
386 if (REGNO (x
) != FRAME_POINTER_REGNUM
387 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
388 && REGNO (x
) != HARD_FRAME_POINTER_REGNUM
393 else if (GET_CODE (x
) == MEM
)
395 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
396 || GET_CODE (x
) == MULT
)
398 register rtx op0
= copy_all_regs (XEXP (x
, 0));
399 register rtx op1
= copy_all_regs (XEXP (x
, 1));
400 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
401 x
= gen_rtx_fmt_ee (GET_CODE (x
), Pmode
, op0
, op1
);
406 /* Return something equivalent to X but valid as a memory address
407 for something of mode MODE. When X is not itself valid, this
408 works by copying X or subexpressions of it into registers. */
411 memory_address (mode
, x
)
412 enum machine_mode mode
;
415 register rtx oldx
= x
;
417 if (GET_CODE (x
) == ADDRESSOF
)
420 #ifdef POINTERS_EXTEND_UNSIGNED
421 if (GET_MODE (x
) == ptr_mode
)
422 x
= convert_memory_address (Pmode
, x
);
425 /* By passing constant addresses thru registers
426 we get a chance to cse them. */
427 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
428 x
= force_reg (Pmode
, x
);
430 /* Accept a QUEUED that refers to a REG
431 even though that isn't a valid address.
432 On attempting to put this in an insn we will call protect_from_queue
433 which will turn it into a REG, which is valid. */
434 else if (GET_CODE (x
) == QUEUED
435 && GET_CODE (QUEUED_VAR (x
)) == REG
)
438 /* We get better cse by rejecting indirect addressing at this stage.
439 Let the combiner create indirect addresses where appropriate.
440 For now, generate the code so that the subexpressions useful to share
441 are visible. But not if cse won't be done! */
444 if (! cse_not_expected
&& GET_CODE (x
) != REG
)
445 x
= break_out_memory_refs (x
);
447 /* At this point, any valid address is accepted. */
448 GO_IF_LEGITIMATE_ADDRESS (mode
, x
, win
);
450 /* If it was valid before but breaking out memory refs invalidated it,
451 use it the old way. */
452 if (memory_address_p (mode
, oldx
))
455 /* Perform machine-dependent transformations on X
456 in certain cases. This is not necessary since the code
457 below can handle all possible cases, but machine-dependent
458 transformations can make better code. */
459 LEGITIMIZE_ADDRESS (x
, oldx
, mode
, win
);
461 /* PLUS and MULT can appear in special ways
462 as the result of attempts to make an address usable for indexing.
463 Usually they are dealt with by calling force_operand, below.
464 But a sum containing constant terms is special
465 if removing them makes the sum a valid address:
466 then we generate that address in a register
467 and index off of it. We do this because it often makes
468 shorter code, and because the addresses thus generated
469 in registers often become common subexpressions. */
470 if (GET_CODE (x
) == PLUS
)
472 rtx constant_term
= const0_rtx
;
473 rtx y
= eliminate_constant_term (x
, &constant_term
);
474 if (constant_term
== const0_rtx
475 || ! memory_address_p (mode
, y
))
476 x
= force_operand (x
, NULL_RTX
);
479 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
480 if (! memory_address_p (mode
, y
))
481 x
= force_operand (x
, NULL_RTX
);
487 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
488 x
= force_operand (x
, NULL_RTX
);
490 /* If we have a register that's an invalid address,
491 it must be a hard reg of the wrong class. Copy it to a pseudo. */
492 else if (GET_CODE (x
) == REG
)
495 /* Last resort: copy the value to a register, since
496 the register is a valid address. */
498 x
= force_reg (Pmode
, x
);
505 if (flag_force_addr
&& ! cse_not_expected
&& GET_CODE (x
) != REG
506 /* Don't copy an addr via a reg if it is one of our stack slots. */
507 && ! (GET_CODE (x
) == PLUS
508 && (XEXP (x
, 0) == virtual_stack_vars_rtx
509 || XEXP (x
, 0) == virtual_incoming_args_rtx
)))
511 if (general_operand (x
, Pmode
))
512 x
= force_reg (Pmode
, x
);
514 x
= force_operand (x
, NULL_RTX
);
520 /* If we didn't change the address, we are done. Otherwise, mark
521 a reg as a pointer if we have REG or REG + CONST_INT. */
524 else if (GET_CODE (x
) == REG
)
525 mark_reg_pointer (x
, 1);
526 else if (GET_CODE (x
) == PLUS
527 && GET_CODE (XEXP (x
, 0)) == REG
528 && GET_CODE (XEXP (x
, 1)) == CONST_INT
)
529 mark_reg_pointer (XEXP (x
, 0), 1);
531 /* OLDX may have been the address on a temporary. Update the address
532 to indicate that X is now used. */
533 update_temp_slot_address (oldx
, x
);
538 /* Like `memory_address' but pretend `flag_force_addr' is 0. */
541 memory_address_noforce (mode
, x
)
542 enum machine_mode mode
;
545 int ambient_force_addr
= flag_force_addr
;
549 val
= memory_address (mode
, x
);
550 flag_force_addr
= ambient_force_addr
;
554 /* Convert a mem ref into one with a valid memory address.
555 Pass through anything else unchanged. */
561 if (GET_CODE (ref
) != MEM
)
563 if (memory_address_p (GET_MODE (ref
), XEXP (ref
, 0)))
565 /* Don't alter REF itself, since that is probably a stack slot. */
566 return change_address (ref
, GET_MODE (ref
), XEXP (ref
, 0));
569 /* Return a modified copy of X with its memory address copied
570 into a temporary register to protect it from side effects.
571 If X is not a MEM, it is returned unchanged (and not copied).
572 Perhaps even if it is a MEM, if there is no need to change it. */
579 if (GET_CODE (x
) != MEM
)
582 if (rtx_unstable_p (addr
))
584 rtx temp
= copy_all_regs (addr
);
586 if (GET_CODE (temp
) != REG
)
587 temp
= copy_to_reg (temp
);
588 mem
= gen_rtx_MEM (GET_MODE (x
), temp
);
590 /* Mark returned memref with in_struct if it's in an array or
591 structure. Copy const and volatile from original memref. */
593 MEM_IN_STRUCT_P (mem
) = MEM_IN_STRUCT_P (x
) || GET_CODE (addr
) == PLUS
;
594 RTX_UNCHANGING_P (mem
) = RTX_UNCHANGING_P (x
);
595 MEM_VOLATILE_P (mem
) = MEM_VOLATILE_P (x
);
601 /* Copy the value or contents of X to a new temp reg and return that reg. */
607 register rtx temp
= gen_reg_rtx (GET_MODE (x
));
609 /* If not an operand, must be an address with PLUS and MULT so
610 do the computation. */
611 if (! general_operand (x
, VOIDmode
))
612 x
= force_operand (x
, temp
);
615 emit_move_insn (temp
, x
);
620 /* Like copy_to_reg but always give the new register mode Pmode
621 in case X is a constant. */
627 return copy_to_mode_reg (Pmode
, x
);
630 /* Like copy_to_reg but always give the new register mode MODE
631 in case X is a constant. */
634 copy_to_mode_reg (mode
, x
)
635 enum machine_mode mode
;
638 register rtx temp
= gen_reg_rtx (mode
);
640 /* If not an operand, must be an address with PLUS and MULT so
641 do the computation. */
642 if (! general_operand (x
, VOIDmode
))
643 x
= force_operand (x
, temp
);
645 if (GET_MODE (x
) != mode
&& GET_MODE (x
) != VOIDmode
)
648 emit_move_insn (temp
, x
);
652 /* Load X into a register if it is not already one.
653 Use mode MODE for the register.
654 X should be valid for mode MODE, but it may be a constant which
655 is valid for all integer modes; that's why caller must specify MODE.
657 The caller must not alter the value in the register we return,
658 since we mark it as a "constant" register. */
662 enum machine_mode mode
;
665 register rtx temp
, insn
, set
;
667 if (GET_CODE (x
) == REG
)
669 temp
= gen_reg_rtx (mode
);
670 insn
= emit_move_insn (temp
, x
);
672 /* Let optimizers know that TEMP's value never changes
673 and that X can be substituted for it. Don't get confused
674 if INSN set something else (such as a SUBREG of TEMP). */
676 && (set
= single_set (insn
)) != 0
677 && SET_DEST (set
) == temp
)
679 rtx note
= find_reg_note (insn
, REG_EQUAL
, NULL_RTX
);
684 REG_NOTES (insn
) = gen_rtx_EXPR_LIST (REG_EQUAL
, x
, REG_NOTES (insn
));
689 /* If X is a memory ref, copy its contents to a new temp reg and return
690 that reg. Otherwise, return X. */
697 if (GET_CODE (x
) != MEM
|| GET_MODE (x
) == BLKmode
)
699 temp
= gen_reg_rtx (GET_MODE (x
));
700 emit_move_insn (temp
, x
);
704 /* Copy X to TARGET (if it's nonzero and a reg)
705 or to a new temp reg and return that reg.
706 MODE is the mode to use for X in case it is a constant. */
709 copy_to_suggested_reg (x
, target
, mode
)
711 enum machine_mode mode
;
715 if (target
&& GET_CODE (target
) == REG
)
718 temp
= gen_reg_rtx (mode
);
720 emit_move_insn (temp
, x
);
724 /* Return the mode to use to store a scalar of TYPE and MODE.
725 PUNSIGNEDP points to the signedness of the type and may be adjusted
726 to show what signedness to use on extension operations.
728 FOR_CALL is non-zero if this call is promoting args for a call. */
731 promote_mode (type
, mode
, punsignedp
, for_call
)
733 enum machine_mode mode
;
737 enum tree_code code
= TREE_CODE (type
);
738 int unsignedp
= *punsignedp
;
740 #ifdef PROMOTE_FOR_CALL_ONLY
748 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
749 case CHAR_TYPE
: case REAL_TYPE
: case OFFSET_TYPE
:
750 PROMOTE_MODE (mode
, unsignedp
, type
);
754 #ifdef POINTERS_EXTEND_UNSIGNED
758 unsignedp
= POINTERS_EXTEND_UNSIGNED
;
766 *punsignedp
= unsignedp
;
770 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
771 This pops when ADJUST is positive. ADJUST need not be constant. */
774 adjust_stack (adjust
)
778 adjust
= protect_from_queue (adjust
, 0);
780 if (adjust
== const0_rtx
)
783 temp
= expand_binop (Pmode
,
784 #ifdef STACK_GROWS_DOWNWARD
789 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
792 if (temp
!= stack_pointer_rtx
)
793 emit_move_insn (stack_pointer_rtx
, temp
);
796 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
797 This pushes when ADJUST is positive. ADJUST need not be constant. */
800 anti_adjust_stack (adjust
)
804 adjust
= protect_from_queue (adjust
, 0);
806 if (adjust
== const0_rtx
)
809 temp
= expand_binop (Pmode
,
810 #ifdef STACK_GROWS_DOWNWARD
815 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
818 if (temp
!= stack_pointer_rtx
)
819 emit_move_insn (stack_pointer_rtx
, temp
);
822 /* Round the size of a block to be pushed up to the boundary required
823 by this machine. SIZE is the desired size, which need not be constant. */
829 #ifdef STACK_BOUNDARY
830 int align
= STACK_BOUNDARY
/ BITS_PER_UNIT
;
833 if (GET_CODE (size
) == CONST_INT
)
835 int new = (INTVAL (size
) + align
- 1) / align
* align
;
836 if (INTVAL (size
) != new)
837 size
= GEN_INT (new);
841 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
842 but we know it can't. So add ourselves and then do
844 size
= expand_binop (Pmode
, add_optab
, size
, GEN_INT (align
- 1),
845 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
846 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, GEN_INT (align
),
848 size
= expand_mult (Pmode
, size
, GEN_INT (align
), NULL_RTX
, 1);
850 #endif /* STACK_BOUNDARY */
854 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
855 to a previously-created save area. If no save area has been allocated,
856 this function will allocate one. If a save area is specified, it
857 must be of the proper mode.
859 The insns are emitted after insn AFTER, if nonzero, otherwise the insns
860 are emitted at the current position. */
863 emit_stack_save (save_level
, psave
, after
)
864 enum save_level save_level
;
869 /* The default is that we use a move insn and save in a Pmode object. */
870 rtx (*fcn
) () = gen_move_insn
;
871 enum machine_mode mode
= Pmode
;
873 /* See if this machine has anything special to do for this kind of save. */
876 #ifdef HAVE_save_stack_block
878 if (HAVE_save_stack_block
)
880 fcn
= gen_save_stack_block
;
881 mode
= insn_operand_mode
[CODE_FOR_save_stack_block
][0];
885 #ifdef HAVE_save_stack_function
887 if (HAVE_save_stack_function
)
889 fcn
= gen_save_stack_function
;
890 mode
= insn_operand_mode
[CODE_FOR_save_stack_function
][0];
894 #ifdef HAVE_save_stack_nonlocal
896 if (HAVE_save_stack_nonlocal
)
898 fcn
= gen_save_stack_nonlocal
;
899 mode
= insn_operand_mode
[(int) CODE_FOR_save_stack_nonlocal
][0];
907 /* If there is no save area and we have to allocate one, do so. Otherwise
908 verify the save area is the proper mode. */
912 if (mode
!= VOIDmode
)
914 if (save_level
== SAVE_NONLOCAL
)
915 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
917 *psave
= sa
= gen_reg_rtx (mode
);
922 if (mode
== VOIDmode
|| GET_MODE (sa
) != mode
)
931 /* We must validize inside the sequence, to ensure that any instructions
932 created by the validize call also get moved to the right place. */
934 sa
= validize_mem (sa
);
935 emit_insn (fcn (sa
, stack_pointer_rtx
));
936 seq
= gen_sequence ();
938 emit_insn_after (seq
, after
);
943 sa
= validize_mem (sa
);
944 emit_insn (fcn (sa
, stack_pointer_rtx
));
948 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
949 area made by emit_stack_save. If it is zero, we have nothing to do.
951 Put any emitted insns after insn AFTER, if nonzero, otherwise at
955 emit_stack_restore (save_level
, sa
, after
)
956 enum save_level save_level
;
960 /* The default is that we use a move insn. */
961 rtx (*fcn
) () = gen_move_insn
;
963 /* See if this machine has anything special to do for this kind of save. */
966 #ifdef HAVE_restore_stack_block
968 if (HAVE_restore_stack_block
)
969 fcn
= gen_restore_stack_block
;
972 #ifdef HAVE_restore_stack_function
974 if (HAVE_restore_stack_function
)
975 fcn
= gen_restore_stack_function
;
978 #ifdef HAVE_restore_stack_nonlocal
981 if (HAVE_restore_stack_nonlocal
)
982 fcn
= gen_restore_stack_nonlocal
;
990 sa
= validize_mem (sa
);
997 emit_insn (fcn (stack_pointer_rtx
, sa
));
998 seq
= gen_sequence ();
1000 emit_insn_after (seq
, after
);
1003 emit_insn (fcn (stack_pointer_rtx
, sa
));
1006 #ifdef SETJMP_VIA_SAVE_AREA
1007 /* Optimize RTL generated by allocate_dynamic_stack_space for targets
1008 where SETJMP_VIA_SAVE_AREA is true. The problem is that on these
1009 platforms, the dynamic stack space used can corrupt the original
1010 frame, thus causing a crash if a longjmp unwinds to it. */
1013 optimize_save_area_alloca (insns
)
1018 for (insn
= insns
; insn
; insn
= NEXT_INSN(insn
))
1022 if (GET_CODE (insn
) != INSN
)
1025 for (note
= REG_NOTES (insn
); note
; note
= XEXP (note
, 1))
1027 if (REG_NOTE_KIND (note
) != REG_SAVE_AREA
)
1030 if (!current_function_calls_setjmp
)
1032 rtx pat
= PATTERN (insn
);
1034 /* If we do not see the note in a pattern matching
1035 these precise characteristics, we did something
1036 entirely wrong in allocate_dynamic_stack_space.
1038 Note, one way this could happen if if SETJMP_VIA_SAVE_AREA
1039 was defined on a machine where stacks grow towards higher
1042 Right now only supported port with stack that grow upward
1043 is the HPPA and it does not define SETJMP_VIA_SAVE_AREA. */
1044 if (GET_CODE (pat
) != SET
1045 || SET_DEST (pat
) != stack_pointer_rtx
1046 || GET_CODE (SET_SRC (pat
)) != MINUS
1047 || XEXP (SET_SRC (pat
), 0) != stack_pointer_rtx
)
1050 /* This will now be transformed into a (set REG REG)
1051 so we can just blow away all the other notes. */
1052 XEXP (SET_SRC (pat
), 1) = XEXP (note
, 0);
1053 REG_NOTES (insn
) = NULL_RTX
;
1057 /* setjmp was called, we must remove the REG_SAVE_AREA
1058 note so that later passes do not get confused by its
1060 if (note
== REG_NOTES (insn
))
1062 REG_NOTES (insn
) = XEXP (note
, 1);
1068 for (srch
= REG_NOTES (insn
); srch
; srch
= XEXP (srch
, 1))
1069 if (XEXP (srch
, 1) == note
)
1072 if (srch
== NULL_RTX
)
1075 XEXP (srch
, 1) = XEXP (note
, 1);
1078 /* Once we've seen the note of interest, we need not look at
1079 the rest of them. */
1084 #endif /* SETJMP_VIA_SAVE_AREA */
1086 /* Return an rtx representing the address of an area of memory dynamically
1087 pushed on the stack. This region of memory is always aligned to
1088 a multiple of BIGGEST_ALIGNMENT.
1090 Any required stack pointer alignment is preserved.
1092 SIZE is an rtx representing the size of the area.
1093 TARGET is a place in which the address can be placed.
1095 KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */
1098 allocate_dynamic_stack_space (size
, target
, known_align
)
1103 #ifdef SETJMP_VIA_SAVE_AREA
1104 rtx setjmpless_size
= NULL_RTX
;
1107 /* If we're asking for zero bytes, it doesn't matter what we point
1108 to since we can't dereference it. But return a reasonable
1110 if (size
== const0_rtx
)
1111 return virtual_stack_dynamic_rtx
;
1113 /* Otherwise, show we're calling alloca or equivalent. */
1114 current_function_calls_alloca
= 1;
1116 /* Ensure the size is in the proper mode. */
1117 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1118 size
= convert_to_mode (Pmode
, size
, 1);
1120 /* We will need to ensure that the address we return is aligned to
1121 BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
1122 always know its final value at this point in the compilation (it
1123 might depend on the size of the outgoing parameter lists, for
1124 example), so we must align the value to be returned in that case.
1125 (Note that STACK_DYNAMIC_OFFSET will have a default non-zero value if
1126 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1127 We must also do an alignment operation on the returned value if
1128 the stack pointer alignment is less strict that BIGGEST_ALIGNMENT.
1130 If we have to align, we must leave space in SIZE for the hole
1131 that might result from the alignment operation. */
1133 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET) || ! defined (STACK_BOUNDARY)
1134 #define MUST_ALIGN 1
1136 #define MUST_ALIGN (STACK_BOUNDARY < BIGGEST_ALIGNMENT)
1141 if (GET_CODE (size
) == CONST_INT
)
1142 size
= GEN_INT (INTVAL (size
)
1143 + (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1));
1145 size
= expand_binop (Pmode
, add_optab
, size
,
1146 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1),
1147 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1150 #ifdef SETJMP_VIA_SAVE_AREA
1151 /* If setjmp restores regs from a save area in the stack frame,
1152 avoid clobbering the reg save area. Note that the offset of
1153 virtual_incoming_args_rtx includes the preallocated stack args space.
1154 It would be no problem to clobber that, but it's on the wrong side
1155 of the old save area. */
1158 = expand_binop (Pmode
, sub_optab
, virtual_stack_dynamic_rtx
,
1159 stack_pointer_rtx
, NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1161 if (!current_function_calls_setjmp
)
1163 int align
= STACK_BOUNDARY
/ BITS_PER_UNIT
;
1165 /* See optimize_save_area_alloca to understand what is being
1168 #if !defined(STACK_BOUNDARY) || !defined(MUST_ALIGN) || (STACK_BOUNDARY != BIGGEST_ALIGNMENT)
1169 /* If anyone creates a target with these characteristics, let them
1170 know that our optimization cannot work correctly in such a case. */
1174 if (GET_CODE (size
) == CONST_INT
)
1176 int new = INTVAL (size
) / align
* align
;
1178 if (INTVAL (size
) != new)
1179 setjmpless_size
= GEN_INT (new);
1181 setjmpless_size
= size
;
1185 /* Since we know overflow is not possible, we avoid using
1186 CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */
1187 setjmpless_size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
,
1188 GEN_INT (align
), NULL_RTX
, 1);
1189 setjmpless_size
= expand_mult (Pmode
, setjmpless_size
,
1190 GEN_INT (align
), NULL_RTX
, 1);
1192 /* Our optimization works based upon being able to perform a simple
1193 transformation of this RTL into a (set REG REG) so make sure things
1194 did in fact end up in a REG. */
1195 if (!arith_operand (setjmpless_size
, Pmode
))
1196 setjmpless_size
= force_reg (Pmode
, setjmpless_size
);
1199 size
= expand_binop (Pmode
, add_optab
, size
, dynamic_offset
,
1200 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1202 #endif /* SETJMP_VIA_SAVE_AREA */
1204 /* Round the size to a multiple of the required stack alignment.
1205 Since the stack if presumed to be rounded before this allocation,
1206 this will maintain the required alignment.
1208 If the stack grows downward, we could save an insn by subtracting
1209 SIZE from the stack pointer and then aligning the stack pointer.
1210 The problem with this is that the stack pointer may be unaligned
1211 between the execution of the subtraction and alignment insns and
1212 some machines do not allow this. Even on those that do, some
1213 signal handlers malfunction if a signal should occur between those
1214 insns. Since this is an extremely rare event, we have no reliable
1215 way of knowing which systems have this problem. So we avoid even
1216 momentarily mis-aligning the stack. */
1218 #ifdef STACK_BOUNDARY
1219 /* If we added a variable amount to SIZE,
1220 we can no longer assume it is aligned. */
1221 #if !defined (SETJMP_VIA_SAVE_AREA)
1222 if (MUST_ALIGN
|| known_align
% STACK_BOUNDARY
!= 0)
1224 size
= round_push (size
);
1227 do_pending_stack_adjust ();
1229 /* If needed, check that we have the required amount of stack. Take into
1230 account what has already been checked. */
1231 if (flag_stack_check
&& ! STACK_CHECK_BUILTIN
)
1232 probe_stack_range (STACK_CHECK_MAX_FRAME_SIZE
+ STACK_CHECK_PROTECT
, size
);
1234 /* Don't use a TARGET that isn't a pseudo. */
1235 if (target
== 0 || GET_CODE (target
) != REG
1236 || REGNO (target
) < FIRST_PSEUDO_REGISTER
)
1237 target
= gen_reg_rtx (Pmode
);
1239 mark_reg_pointer (target
, known_align
/ BITS_PER_UNIT
);
1241 /* Perform the required allocation from the stack. Some systems do
1242 this differently than simply incrementing/decrementing from the
1243 stack pointer, such as acquiring the space by calling malloc(). */
1244 #ifdef HAVE_allocate_stack
1245 if (HAVE_allocate_stack
)
1247 enum machine_mode mode
;
1249 if (insn_operand_predicate
[(int) CODE_FOR_allocate_stack
][0]
1250 && ! ((*insn_operand_predicate
[(int) CODE_FOR_allocate_stack
][0])
1252 target
= copy_to_mode_reg (Pmode
, target
);
1253 mode
= insn_operand_mode
[(int) CODE_FOR_allocate_stack
][1];
1254 size
= convert_modes (mode
, ptr_mode
, size
, 1);
1255 if (insn_operand_predicate
[(int) CODE_FOR_allocate_stack
][1]
1256 && ! ((*insn_operand_predicate
[(int) CODE_FOR_allocate_stack
][1])
1258 size
= copy_to_mode_reg (mode
, size
);
1260 emit_insn (gen_allocate_stack (target
, size
));
1265 #ifndef STACK_GROWS_DOWNWARD
1266 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1268 size
= convert_modes (Pmode
, ptr_mode
, size
, 1);
1269 anti_adjust_stack (size
);
1270 #ifdef SETJMP_VIA_SAVE_AREA
1271 if (setjmpless_size
!= NULL_RTX
)
1273 rtx note_target
= get_last_insn ();
1275 REG_NOTES (note_target
) = gen_rtx (EXPR_LIST
, REG_SAVE_AREA
,
1277 REG_NOTES (note_target
));
1279 #endif /* SETJMP_VIA_SAVE_AREA */
1280 #ifdef STACK_GROWS_DOWNWARD
1281 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1287 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1288 but we know it can't. So add ourselves and then do
1290 target
= expand_binop (Pmode
, add_optab
, target
,
1291 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1),
1292 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1293 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1294 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
),
1296 target
= expand_mult (Pmode
, target
,
1297 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
),
1301 /* Some systems require a particular insn to refer to the stack
1302 to make the pages exist. */
1305 emit_insn (gen_probe ());
1308 /* Record the new stack level for nonlocal gotos. */
1309 if (nonlocal_goto_handler_slot
!= 0)
1310 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
, NULL_RTX
);
1315 /* Emit one stack probe at ADDRESS, an address within the stack. */
1318 emit_stack_probe (address
)
1321 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1323 MEM_VOLATILE_P (memref
) = 1;
1325 if (STACK_CHECK_PROBE_LOAD
)
1326 emit_move_insn (gen_reg_rtx (word_mode
), memref
);
1328 emit_move_insn (memref
, const0_rtx
);
1331 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1332 FIRST is a constant and size is a Pmode RTX. These are offsets from the
1333 current stack pointer. STACK_GROWS_DOWNWARD says whether to add or
1334 subtract from the stack. If SIZE is constant, this is done
1335 with a fixed number of probes. Otherwise, we must make a loop. */
1337 #ifdef STACK_GROWS_DOWNWARD
1338 #define STACK_GROW_OP MINUS
1340 #define STACK_GROW_OP PLUS
1344 probe_stack_range (first
, size
)
1345 HOST_WIDE_INT first
;
1348 /* First see if we have an insn to check the stack. Use it if so. */
1349 #ifdef HAVE_check_stack
1350 if (HAVE_check_stack
)
1353 = force_operand (gen_rtx_STACK_GROW_OP (Pmode
,
1355 plus_constant (size
, first
)),
1358 if (insn_operand_predicate
[(int) CODE_FOR_check_stack
][0]
1359 && ! ((*insn_operand_predicate
[(int) CODE_FOR_check_stack
][0])
1360 (last_address
, Pmode
)))
1361 last_address
= copy_to_mode_reg (Pmode
, last_address
);
1363 emit_insn (gen_check_stack (last_address
));
1368 /* If we have to generate explicit probes, see if we have a constant
1369 small number of them to generate. If so, that's the easy case. */
1370 if (GET_CODE (size
) == CONST_INT
&& INTVAL (size
) < 10)
1372 HOST_WIDE_INT offset
;
1374 /* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL
1375 for values of N from 1 until it exceeds LAST. If only one
1376 probe is needed, this will not generate any code. Then probe
1378 for (offset
= first
+ STACK_CHECK_PROBE_INTERVAL
;
1379 offset
< INTVAL (size
);
1380 offset
= offset
+ STACK_CHECK_PROBE_INTERVAL
)
1381 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1385 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1387 plus_constant (size
, first
)));
1390 /* In the variable case, do the same as above, but in a loop. We emit loop
1391 notes so that loop optimization can be done. */
1395 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1397 GEN_INT (first
+ STACK_CHECK_PROBE_INTERVAL
)),
1400 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1402 plus_constant (size
, first
)),
1404 rtx incr
= GEN_INT (STACK_CHECK_PROBE_INTERVAL
);
1405 rtx loop_lab
= gen_label_rtx ();
1406 rtx test_lab
= gen_label_rtx ();
1407 rtx end_lab
= gen_label_rtx ();
1410 if (GET_CODE (test_addr
) != REG
1411 || REGNO (test_addr
) < FIRST_PSEUDO_REGISTER
)
1412 test_addr
= force_reg (Pmode
, test_addr
);
1414 emit_note (NULL_PTR
, NOTE_INSN_LOOP_BEG
);
1415 emit_jump (test_lab
);
1417 emit_label (loop_lab
);
1418 emit_stack_probe (test_addr
);
1420 emit_note (NULL_PTR
, NOTE_INSN_LOOP_CONT
);
1422 #ifdef STACK_GROWS_DOWNWARD
1423 #define CMP_OPCODE GTU
1424 temp
= expand_binop (Pmode
, sub_optab
, test_addr
, incr
, test_addr
,
1427 #define CMP_OPCODE LTU
1428 temp
= expand_binop (Pmode
, add_optab
, test_addr
, incr
, test_addr
,
1432 if (temp
!= test_addr
)
1435 emit_label (test_lab
);
1436 emit_cmp_insn (test_addr
, last_addr
, CMP_OPCODE
, NULL_RTX
, Pmode
, 1, 0);
1437 emit_jump_insn ((*bcc_gen_fctn
[(int) CMP_OPCODE
]) (loop_lab
));
1438 emit_jump (end_lab
);
1439 emit_note (NULL_PTR
, NOTE_INSN_LOOP_END
);
1440 emit_label (end_lab
);
1442 /* If will be doing stupid optimization, show test_addr is still live. */
1444 emit_insn (gen_rtx_USE (VOIDmode
, test_addr
));
1446 emit_stack_probe (last_addr
);
1450 /* Return an rtx representing the register or memory location
1451 in which a scalar value of data type VALTYPE
1452 was returned by a function call to function FUNC.
1453 FUNC is a FUNCTION_DECL node if the precise function is known,
1457 hard_function_value (valtype
, func
)
1461 rtx val
= FUNCTION_VALUE (valtype
, func
);
1462 if (GET_CODE (val
) == REG
1463 && GET_MODE (val
) == BLKmode
)
1465 int bytes
= int_size_in_bytes (valtype
);
1466 enum machine_mode tmpmode
;
1467 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1468 tmpmode
!= MAX_MACHINE_MODE
;
1469 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1471 /* Have we found a large enough mode? */
1472 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1476 /* No suitable mode found. */
1477 if (tmpmode
== MAX_MACHINE_MODE
)
1480 PUT_MODE (val
, tmpmode
);
1485 /* Return an rtx representing the register or memory location
1486 in which a scalar value of mode MODE was returned by a library call. */
1489 hard_libcall_value (mode
)
1490 enum machine_mode mode
;
1492 return LIBCALL_VALUE (mode
);
1495 /* Look up the tree code for a given rtx code
1496 to provide the arithmetic operation for REAL_ARITHMETIC.
1497 The function returns an int because the caller may not know
1498 what `enum tree_code' means. */
1501 rtx_to_tree_code (code
)
1504 enum tree_code tcode
;
1527 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1530 return ((int) tcode
);