1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987, 1991, 1994, 1995, 1996 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. */
27 #include "hard-reg-set.h"
28 #include "insn-config.h"
30 #include "insn-flags.h"
31 #include "insn-codes.h"
33 static rtx break_out_memory_refs
PROTO((rtx
));
35 /* Return an rtx for the sum of X and the integer C.
37 This function should be used via the `plus_constant' macro. */
40 plus_constant_wide (x
, c
)
42 register HOST_WIDE_INT c
;
44 register RTX_CODE code
;
45 register enum machine_mode mode
;
59 return GEN_INT (INTVAL (x
) + c
);
63 HOST_WIDE_INT l1
= CONST_DOUBLE_LOW (x
);
64 HOST_WIDE_INT h1
= CONST_DOUBLE_HIGH (x
);
66 HOST_WIDE_INT h2
= c
< 0 ? ~0 : 0;
69 add_double (l1
, h1
, l2
, h2
, &lv
, &hv
);
71 return immed_double_const (lv
, hv
, VOIDmode
);
75 /* If this is a reference to the constant pool, try replacing it with
76 a reference to a new constant. If the resulting address isn't
77 valid, don't return it because we have no way to validize it. */
78 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
79 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
82 = force_const_mem (GET_MODE (x
),
83 plus_constant (get_pool_constant (XEXP (x
, 0)),
85 if (memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
91 /* If adding to something entirely constant, set a flag
92 so that we can add a CONST around the result. */
103 /* The interesting case is adding the integer to a sum.
104 Look for constant term in the sum and combine
105 with C. For an integer constant term, we make a combined
106 integer. For a constant term that is not an explicit integer,
107 we cannot really combine, but group them together anyway.
109 Use a recursive call in case the remaining operand is something
110 that we handle specially, such as a SYMBOL_REF. */
112 if (GET_CODE (XEXP (x
, 1)) == CONST_INT
)
113 return plus_constant (XEXP (x
, 0), c
+ INTVAL (XEXP (x
, 1)));
114 else if (CONSTANT_P (XEXP (x
, 0)))
115 return gen_rtx (PLUS
, mode
,
116 plus_constant (XEXP (x
, 0), c
),
118 else if (CONSTANT_P (XEXP (x
, 1)))
119 return gen_rtx (PLUS
, mode
,
121 plus_constant (XEXP (x
, 1), c
));
125 x
= gen_rtx (PLUS
, mode
, x
, GEN_INT (c
));
127 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
129 else if (all_constant
)
130 return gen_rtx (CONST
, mode
, x
);
135 /* This is the same as `plus_constant', except that it handles LO_SUM.
137 This function should be used via the `plus_constant_for_output' macro. */
140 plus_constant_for_output_wide (x
, c
)
142 register HOST_WIDE_INT c
;
144 register RTX_CODE code
= GET_CODE (x
);
145 register enum machine_mode mode
= GET_MODE (x
);
146 int all_constant
= 0;
148 if (GET_CODE (x
) == LO_SUM
)
149 return gen_rtx (LO_SUM
, mode
, XEXP (x
, 0),
150 plus_constant_for_output (XEXP (x
, 1), c
));
153 return plus_constant (x
, c
);
156 /* If X is a sum, return a new sum like X but lacking any constant terms.
157 Add all the removed constant terms into *CONSTPTR.
158 X itself is not altered. The result != X if and only if
159 it is not isomorphic to X. */
162 eliminate_constant_term (x
, constptr
)
169 if (GET_CODE (x
) != PLUS
)
172 /* First handle constants appearing at this level explicitly. */
173 if (GET_CODE (XEXP (x
, 1)) == CONST_INT
174 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
176 && GET_CODE (tem
) == CONST_INT
)
179 return eliminate_constant_term (XEXP (x
, 0), constptr
);
183 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
184 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
185 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
186 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
188 && GET_CODE (tem
) == CONST_INT
)
191 return gen_rtx (PLUS
, GET_MODE (x
), x0
, x1
);
197 /* Returns the insn that next references REG after INSN, or 0
198 if REG is clobbered before next referenced or we cannot find
199 an insn that references REG in a straight-line piece of code. */
202 find_next_ref (reg
, insn
)
208 for (insn
= NEXT_INSN (insn
); insn
; insn
= next
)
210 next
= NEXT_INSN (insn
);
211 if (GET_CODE (insn
) == NOTE
)
213 if (GET_CODE (insn
) == CODE_LABEL
214 || GET_CODE (insn
) == BARRIER
)
216 if (GET_CODE (insn
) == INSN
217 || GET_CODE (insn
) == JUMP_INSN
218 || GET_CODE (insn
) == CALL_INSN
)
220 if (reg_set_p (reg
, insn
))
222 if (reg_mentioned_p (reg
, PATTERN (insn
)))
224 if (GET_CODE (insn
) == JUMP_INSN
)
226 if (simplejump_p (insn
))
227 next
= JUMP_LABEL (insn
);
231 if (GET_CODE (insn
) == CALL_INSN
232 && REGNO (reg
) < FIRST_PSEUDO_REGISTER
233 && call_used_regs
[REGNO (reg
)])
242 /* Return an rtx for the size in bytes of the value of EXP. */
248 tree size
= size_in_bytes (TREE_TYPE (exp
));
250 if (TREE_CODE (size
) != INTEGER_CST
251 && contains_placeholder_p (size
))
252 size
= build (WITH_RECORD_EXPR
, sizetype
, size
, exp
);
254 return expand_expr (size
, NULL_RTX
, TYPE_MODE (sizetype
), 0);
257 /* Return a copy of X in which all memory references
258 and all constants that involve symbol refs
259 have been replaced with new temporary registers.
260 Also emit code to load the memory locations and constants
261 into those registers.
263 If X contains no such constants or memory references,
264 X itself (not a copy) is returned.
266 If a constant is found in the address that is not a legitimate constant
267 in an insn, it is left alone in the hope that it might be valid in the
270 X may contain no arithmetic except addition, subtraction and multiplication.
271 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
274 break_out_memory_refs (x
)
277 if (GET_CODE (x
) == MEM
278 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
279 && GET_MODE (x
) != VOIDmode
))
280 x
= force_reg (GET_MODE (x
), x
);
281 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
282 || GET_CODE (x
) == MULT
)
284 register rtx op0
= break_out_memory_refs (XEXP (x
, 0));
285 register rtx op1
= break_out_memory_refs (XEXP (x
, 1));
287 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
288 x
= gen_rtx (GET_CODE (x
), Pmode
, op0
, op1
);
294 #ifdef POINTERS_EXTEND_UNSIGNED
296 /* Given X, a memory address in ptr_mode, convert it to an address
297 in Pmode, or vice versa (TO_MODE says which way). We take advantage of
298 the fact that pointers are not allowed to overflow by commuting arithmetic
299 operations over conversions so that address arithmetic insns can be
303 convert_memory_address (to_mode
, x
)
304 enum machine_mode to_mode
;
307 enum machine_mode from_mode
= to_mode
== ptr_mode
? Pmode
: ptr_mode
;
310 /* Here we handle some special cases. If none of them apply, fall through
311 to the default case. */
312 switch (GET_CODE (x
))
319 return gen_rtx (LABEL_REF
, to_mode
, XEXP (x
, 0));
322 temp
= gen_rtx (SYMBOL_REF
, to_mode
, XSTR (x
, 0));
323 SYMBOL_REF_FLAG (temp
) = SYMBOL_REF_FLAG (x
);
327 return gen_rtx (CONST
, to_mode
,
328 convert_memory_address (to_mode
, XEXP (x
, 0)));
332 /* For addition the second operand is a small constant, we can safely
333 permute the converstion and addition operation. We can always safely
334 permute them if we are making the address narrower. In addition,
335 always permute the operations if this is a constant. */
336 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
337 || (GET_CODE (x
) == PLUS
&& GET_CODE (XEXP (x
, 1)) == CONST_INT
338 && (INTVAL (XEXP (x
, 1)) + 20000 < 40000
339 || CONSTANT_P (XEXP (x
, 0)))))
340 return gen_rtx (GET_CODE (x
), to_mode
,
341 convert_memory_address (to_mode
, XEXP (x
, 0)),
342 convert_memory_address (to_mode
, XEXP (x
, 1)));
345 return convert_modes (to_mode
, from_mode
,
346 x
, POINTERS_EXTEND_UNSIGNED
);
350 /* Given a memory address or facsimile X, construct a new address,
351 currently equivalent, that is stable: future stores won't change it.
353 X must be composed of constants, register and memory references
354 combined with addition, subtraction and multiplication:
355 in other words, just what you can get from expand_expr if sum_ok is 1.
357 Works by making copies of all regs and memory locations used
358 by X and combining them the same way X does.
359 You could also stabilize the reference to this address
360 by copying the address to a register with copy_to_reg;
361 but then you wouldn't get indexed addressing in the reference. */
367 if (GET_CODE (x
) == REG
)
369 if (REGNO (x
) != FRAME_POINTER_REGNUM
370 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
371 && REGNO (x
) != HARD_FRAME_POINTER_REGNUM
376 else if (GET_CODE (x
) == MEM
)
378 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
379 || GET_CODE (x
) == MULT
)
381 register rtx op0
= copy_all_regs (XEXP (x
, 0));
382 register rtx op1
= copy_all_regs (XEXP (x
, 1));
383 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
384 x
= gen_rtx (GET_CODE (x
), Pmode
, op0
, op1
);
389 /* Return something equivalent to X but valid as a memory address
390 for something of mode MODE. When X is not itself valid, this
391 works by copying X or subexpressions of it into registers. */
394 memory_address (mode
, x
)
395 enum machine_mode mode
;
398 register rtx oldx
= x
;
400 #ifdef POINTERS_EXTEND_UNSIGNED
401 if (GET_MODE (x
) == ptr_mode
)
402 x
= convert_memory_address (Pmode
, x
);
405 /* By passing constant addresses thru registers
406 we get a chance to cse them. */
407 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
408 x
= force_reg (Pmode
, x
);
410 /* Accept a QUEUED that refers to a REG
411 even though that isn't a valid address.
412 On attempting to put this in an insn we will call protect_from_queue
413 which will turn it into a REG, which is valid. */
414 else if (GET_CODE (x
) == QUEUED
415 && GET_CODE (QUEUED_VAR (x
)) == REG
)
418 /* We get better cse by rejecting indirect addressing at this stage.
419 Let the combiner create indirect addresses where appropriate.
420 For now, generate the code so that the subexpressions useful to share
421 are visible. But not if cse won't be done! */
424 if (! cse_not_expected
&& GET_CODE (x
) != REG
)
425 x
= break_out_memory_refs (x
);
427 /* At this point, any valid address is accepted. */
428 GO_IF_LEGITIMATE_ADDRESS (mode
, x
, win
);
430 /* If it was valid before but breaking out memory refs invalidated it,
431 use it the old way. */
432 if (memory_address_p (mode
, oldx
))
435 /* Perform machine-dependent transformations on X
436 in certain cases. This is not necessary since the code
437 below can handle all possible cases, but machine-dependent
438 transformations can make better code. */
439 LEGITIMIZE_ADDRESS (x
, oldx
, mode
, win
);
441 /* PLUS and MULT can appear in special ways
442 as the result of attempts to make an address usable for indexing.
443 Usually they are dealt with by calling force_operand, below.
444 But a sum containing constant terms is special
445 if removing them makes the sum a valid address:
446 then we generate that address in a register
447 and index off of it. We do this because it often makes
448 shorter code, and because the addresses thus generated
449 in registers often become common subexpressions. */
450 if (GET_CODE (x
) == PLUS
)
452 rtx constant_term
= const0_rtx
;
453 rtx y
= eliminate_constant_term (x
, &constant_term
);
454 if (constant_term
== const0_rtx
455 || ! memory_address_p (mode
, y
))
456 x
= force_operand (x
, NULL_RTX
);
459 y
= gen_rtx (PLUS
, GET_MODE (x
), copy_to_reg (y
), constant_term
);
460 if (! memory_address_p (mode
, y
))
461 x
= force_operand (x
, NULL_RTX
);
467 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
468 x
= force_operand (x
, NULL_RTX
);
470 /* If we have a register that's an invalid address,
471 it must be a hard reg of the wrong class. Copy it to a pseudo. */
472 else if (GET_CODE (x
) == REG
)
475 /* Last resort: copy the value to a register, since
476 the register is a valid address. */
478 x
= force_reg (Pmode
, x
);
485 if (flag_force_addr
&& ! cse_not_expected
&& GET_CODE (x
) != REG
486 /* Don't copy an addr via a reg if it is one of our stack slots. */
487 && ! (GET_CODE (x
) == PLUS
488 && (XEXP (x
, 0) == virtual_stack_vars_rtx
489 || XEXP (x
, 0) == virtual_incoming_args_rtx
)))
491 if (general_operand (x
, Pmode
))
492 x
= force_reg (Pmode
, x
);
494 x
= force_operand (x
, NULL_RTX
);
500 /* If we didn't change the address, we are done. Otherwise, mark
501 a reg as a pointer if we have REG or REG + CONST_INT. */
504 else if (GET_CODE (x
) == REG
)
505 mark_reg_pointer (x
, 1);
506 else if (GET_CODE (x
) == PLUS
507 && GET_CODE (XEXP (x
, 0)) == REG
508 && GET_CODE (XEXP (x
, 1)) == CONST_INT
)
509 mark_reg_pointer (XEXP (x
, 0), 1);
511 /* OLDX may have been the address on a temporary. Update the address
512 to indicate that X is now used. */
513 update_temp_slot_address (oldx
, x
);
518 /* Like `memory_address' but pretend `flag_force_addr' is 0. */
521 memory_address_noforce (mode
, x
)
522 enum machine_mode mode
;
525 int ambient_force_addr
= flag_force_addr
;
529 val
= memory_address (mode
, x
);
530 flag_force_addr
= ambient_force_addr
;
534 /* Convert a mem ref into one with a valid memory address.
535 Pass through anything else unchanged. */
541 if (GET_CODE (ref
) != MEM
)
543 if (memory_address_p (GET_MODE (ref
), XEXP (ref
, 0)))
545 /* Don't alter REF itself, since that is probably a stack slot. */
546 return change_address (ref
, GET_MODE (ref
), XEXP (ref
, 0));
549 /* Return a modified copy of X with its memory address copied
550 into a temporary register to protect it from side effects.
551 If X is not a MEM, it is returned unchanged (and not copied).
552 Perhaps even if it is a MEM, if there is no need to change it. */
559 if (GET_CODE (x
) != MEM
)
562 if (rtx_unstable_p (addr
))
564 rtx temp
= copy_all_regs (addr
);
566 if (GET_CODE (temp
) != REG
)
567 temp
= copy_to_reg (temp
);
568 mem
= gen_rtx (MEM
, GET_MODE (x
), temp
);
570 /* Mark returned memref with in_struct if it's in an array or
571 structure. Copy const and volatile from original memref. */
573 MEM_IN_STRUCT_P (mem
) = MEM_IN_STRUCT_P (x
) || GET_CODE (addr
) == PLUS
;
574 RTX_UNCHANGING_P (mem
) = RTX_UNCHANGING_P (x
);
575 MEM_VOLATILE_P (mem
) = MEM_VOLATILE_P (x
);
581 /* Copy the value or contents of X to a new temp reg and return that reg. */
587 register rtx temp
= gen_reg_rtx (GET_MODE (x
));
589 /* If not an operand, must be an address with PLUS and MULT so
590 do the computation. */
591 if (! general_operand (x
, VOIDmode
))
592 x
= force_operand (x
, temp
);
595 emit_move_insn (temp
, x
);
600 /* Like copy_to_reg but always give the new register mode Pmode
601 in case X is a constant. */
607 return copy_to_mode_reg (Pmode
, x
);
610 /* Like copy_to_reg but always give the new register mode MODE
611 in case X is a constant. */
614 copy_to_mode_reg (mode
, x
)
615 enum machine_mode mode
;
618 register rtx temp
= gen_reg_rtx (mode
);
620 /* If not an operand, must be an address with PLUS and MULT so
621 do the computation. */
622 if (! general_operand (x
, VOIDmode
))
623 x
= force_operand (x
, temp
);
625 if (GET_MODE (x
) != mode
&& GET_MODE (x
) != VOIDmode
)
628 emit_move_insn (temp
, x
);
632 /* Load X into a register if it is not already one.
633 Use mode MODE for the register.
634 X should be valid for mode MODE, but it may be a constant which
635 is valid for all integer modes; that's why caller must specify MODE.
637 The caller must not alter the value in the register we return,
638 since we mark it as a "constant" register. */
642 enum machine_mode mode
;
645 register rtx temp
, insn
, set
;
647 if (GET_CODE (x
) == REG
)
649 temp
= gen_reg_rtx (mode
);
650 insn
= emit_move_insn (temp
, x
);
652 /* Let optimizers know that TEMP's value never changes
653 and that X can be substituted for it. Don't get confused
654 if INSN set something else (such as a SUBREG of TEMP). */
656 && (set
= single_set (insn
)) != 0
657 && SET_DEST (set
) == temp
)
659 rtx note
= find_reg_note (insn
, REG_EQUAL
, NULL_RTX
);
664 REG_NOTES (insn
) = gen_rtx (EXPR_LIST
, REG_EQUAL
, x
, REG_NOTES (insn
));
669 /* If X is a memory ref, copy its contents to a new temp reg and return
670 that reg. Otherwise, return X. */
677 if (GET_CODE (x
) != MEM
|| GET_MODE (x
) == BLKmode
)
679 temp
= gen_reg_rtx (GET_MODE (x
));
680 emit_move_insn (temp
, x
);
684 /* Copy X to TARGET (if it's nonzero and a reg)
685 or to a new temp reg and return that reg.
686 MODE is the mode to use for X in case it is a constant. */
689 copy_to_suggested_reg (x
, target
, mode
)
691 enum machine_mode mode
;
695 if (target
&& GET_CODE (target
) == REG
)
698 temp
= gen_reg_rtx (mode
);
700 emit_move_insn (temp
, x
);
704 /* Return the mode to use to store a scalar of TYPE and MODE.
705 PUNSIGNEDP points to the signedness of the type and may be adjusted
706 to show what signedness to use on extension operations.
708 FOR_CALL is non-zero if this call is promoting args for a call. */
711 promote_mode (type
, mode
, punsignedp
, for_call
)
713 enum machine_mode mode
;
717 enum tree_code code
= TREE_CODE (type
);
718 int unsignedp
= *punsignedp
;
720 #ifdef PROMOTE_FOR_CALL_ONLY
728 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
729 case CHAR_TYPE
: case REAL_TYPE
: case OFFSET_TYPE
:
730 PROMOTE_MODE (mode
, unsignedp
, type
);
734 #ifdef POINTERS_EXTEND_UNSIGNED
738 unsignedp
= POINTERS_EXTEND_UNSIGNED
;
743 *punsignedp
= unsignedp
;
747 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
748 This pops when ADJUST is positive. ADJUST need not be constant. */
751 adjust_stack (adjust
)
755 adjust
= protect_from_queue (adjust
, 0);
757 if (adjust
== const0_rtx
)
760 temp
= expand_binop (Pmode
,
761 #ifdef STACK_GROWS_DOWNWARD
766 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
769 if (temp
!= stack_pointer_rtx
)
770 emit_move_insn (stack_pointer_rtx
, temp
);
773 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
774 This pushes when ADJUST is positive. ADJUST need not be constant. */
777 anti_adjust_stack (adjust
)
781 adjust
= protect_from_queue (adjust
, 0);
783 if (adjust
== const0_rtx
)
786 temp
= expand_binop (Pmode
,
787 #ifdef STACK_GROWS_DOWNWARD
792 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
795 if (temp
!= stack_pointer_rtx
)
796 emit_move_insn (stack_pointer_rtx
, temp
);
799 /* Round the size of a block to be pushed up to the boundary required
800 by this machine. SIZE is the desired size, which need not be constant. */
806 #ifdef STACK_BOUNDARY
807 int align
= STACK_BOUNDARY
/ BITS_PER_UNIT
;
810 if (GET_CODE (size
) == CONST_INT
)
812 int new = (INTVAL (size
) + align
- 1) / align
* align
;
813 if (INTVAL (size
) != new)
814 size
= GEN_INT (new);
818 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
819 but we know it can't. So add ourselves and then do
821 size
= expand_binop (Pmode
, add_optab
, size
, GEN_INT (align
- 1),
822 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
823 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, GEN_INT (align
),
825 size
= expand_mult (Pmode
, size
, GEN_INT (align
), NULL_RTX
, 1);
827 #endif /* STACK_BOUNDARY */
831 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
832 to a previously-created save area. If no save area has been allocated,
833 this function will allocate one. If a save area is specified, it
834 must be of the proper mode.
836 The insns are emitted after insn AFTER, if nonzero, otherwise the insns
837 are emitted at the current position. */
840 emit_stack_save (save_level
, psave
, after
)
841 enum save_level save_level
;
846 /* The default is that we use a move insn and save in a Pmode object. */
847 rtx (*fcn
) () = gen_move_insn
;
848 enum machine_mode mode
= Pmode
;
850 /* See if this machine has anything special to do for this kind of save. */
853 #ifdef HAVE_save_stack_block
855 if (HAVE_save_stack_block
)
857 fcn
= gen_save_stack_block
;
858 mode
= insn_operand_mode
[CODE_FOR_save_stack_block
][0];
862 #ifdef HAVE_save_stack_function
864 if (HAVE_save_stack_function
)
866 fcn
= gen_save_stack_function
;
867 mode
= insn_operand_mode
[CODE_FOR_save_stack_function
][0];
871 #ifdef HAVE_save_stack_nonlocal
873 if (HAVE_save_stack_nonlocal
)
875 fcn
= gen_save_stack_nonlocal
;
876 mode
= insn_operand_mode
[(int) CODE_FOR_save_stack_nonlocal
][0];
882 /* If there is no save area and we have to allocate one, do so. Otherwise
883 verify the save area is the proper mode. */
887 if (mode
!= VOIDmode
)
889 if (save_level
== SAVE_NONLOCAL
)
890 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
892 *psave
= sa
= gen_reg_rtx (mode
);
897 if (mode
== VOIDmode
|| GET_MODE (sa
) != mode
)
906 /* We must validize inside the sequence, to ensure that any instructions
907 created by the validize call also get moved to the right place. */
909 sa
= validize_mem (sa
);
910 emit_insn (fcn (sa
, stack_pointer_rtx
));
911 seq
= gen_sequence ();
913 emit_insn_after (seq
, after
);
918 sa
= validize_mem (sa
);
919 emit_insn (fcn (sa
, stack_pointer_rtx
));
923 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
924 area made by emit_stack_save. If it is zero, we have nothing to do.
926 Put any emitted insns after insn AFTER, if nonzero, otherwise at
930 emit_stack_restore (save_level
, sa
, after
)
931 enum save_level save_level
;
935 /* The default is that we use a move insn. */
936 rtx (*fcn
) () = gen_move_insn
;
938 /* See if this machine has anything special to do for this kind of save. */
941 #ifdef HAVE_restore_stack_block
943 if (HAVE_restore_stack_block
)
944 fcn
= gen_restore_stack_block
;
947 #ifdef HAVE_restore_stack_function
949 if (HAVE_restore_stack_function
)
950 fcn
= gen_restore_stack_function
;
953 #ifdef HAVE_restore_stack_nonlocal
956 if (HAVE_restore_stack_nonlocal
)
957 fcn
= gen_restore_stack_nonlocal
;
963 sa
= validize_mem (sa
);
970 emit_insn (fcn (stack_pointer_rtx
, sa
));
971 seq
= gen_sequence ();
973 emit_insn_after (seq
, after
);
976 emit_insn (fcn (stack_pointer_rtx
, sa
));
979 /* Return an rtx representing the address of an area of memory dynamically
980 pushed on the stack. This region of memory is always aligned to
981 a multiple of BIGGEST_ALIGNMENT.
983 Any required stack pointer alignment is preserved.
985 SIZE is an rtx representing the size of the area.
986 TARGET is a place in which the address can be placed.
988 KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */
991 allocate_dynamic_stack_space (size
, target
, known_align
)
996 /* If we're asking for zero bytes, it doesn't matter what we point
997 to since we can't dereference it. But return a reasonable
999 if (size
== const0_rtx
)
1000 return virtual_stack_dynamic_rtx
;
1002 /* Otherwise, show we're calling alloca or equivalent. */
1003 current_function_calls_alloca
= 1;
1005 /* Ensure the size is in the proper mode. */
1006 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1007 size
= convert_to_mode (Pmode
, size
, 1);
1009 /* We will need to ensure that the address we return is aligned to
1010 BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
1011 always know its final value at this point in the compilation (it
1012 might depend on the size of the outgoing parameter lists, for
1013 example), so we must align the value to be returned in that case.
1014 (Note that STACK_DYNAMIC_OFFSET will have a default non-zero value if
1015 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1016 We must also do an alignment operation on the returned value if
1017 the stack pointer alignment is less strict that BIGGEST_ALIGNMENT.
1019 If we have to align, we must leave space in SIZE for the hole
1020 that might result from the alignment operation. */
1022 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET) || ! defined (STACK_BOUNDARY)
1023 #define MUST_ALIGN 1
1025 #define MUST_ALIGN (STACK_BOUNDARY < BIGGEST_ALIGNMENT)
1030 if (GET_CODE (size
) == CONST_INT
)
1031 size
= GEN_INT (INTVAL (size
)
1032 + (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1));
1034 size
= expand_binop (Pmode
, add_optab
, size
,
1035 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1),
1036 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1039 #ifdef SETJMP_VIA_SAVE_AREA
1040 /* If setjmp restores regs from a save area in the stack frame,
1041 avoid clobbering the reg save area. Note that the offset of
1042 virtual_incoming_args_rtx includes the preallocated stack args space.
1043 It would be no problem to clobber that, but it's on the wrong side
1044 of the old save area. */
1047 = expand_binop (Pmode
, sub_optab
, virtual_stack_dynamic_rtx
,
1048 stack_pointer_rtx
, NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1049 size
= expand_binop (Pmode
, add_optab
, size
, dynamic_offset
,
1050 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1052 #endif /* SETJMP_VIA_SAVE_AREA */
1054 /* Round the size to a multiple of the required stack alignment.
1055 Since the stack if presumed to be rounded before this allocation,
1056 this will maintain the required alignment.
1058 If the stack grows downward, we could save an insn by subtracting
1059 SIZE from the stack pointer and then aligning the stack pointer.
1060 The problem with this is that the stack pointer may be unaligned
1061 between the execution of the subtraction and alignment insns and
1062 some machines do not allow this. Even on those that do, some
1063 signal handlers malfunction if a signal should occur between those
1064 insns. Since this is an extremely rare event, we have no reliable
1065 way of knowing which systems have this problem. So we avoid even
1066 momentarily mis-aligning the stack. */
1068 #ifdef STACK_BOUNDARY
1069 /* If we added a variable amount to SIZE,
1070 we can no longer assume it is aligned. */
1071 #if !defined (SETJMP_VIA_SAVE_AREA)
1072 if (MUST_ALIGN
|| known_align
% STACK_BOUNDARY
!= 0)
1074 size
= round_push (size
);
1077 do_pending_stack_adjust ();
1079 /* Don't use a TARGET that isn't a pseudo. */
1080 if (target
== 0 || GET_CODE (target
) != REG
1081 || REGNO (target
) < FIRST_PSEUDO_REGISTER
)
1082 target
= gen_reg_rtx (Pmode
);
1084 mark_reg_pointer (target
, known_align
/ BITS_PER_UNIT
);
1086 #ifndef STACK_GROWS_DOWNWARD
1087 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1090 /* Perform the required allocation from the stack. Some systems do
1091 this differently than simply incrementing/decrementing from the
1093 #ifdef HAVE_allocate_stack
1094 if (HAVE_allocate_stack
)
1096 enum machine_mode mode
1097 = insn_operand_mode
[(int) CODE_FOR_allocate_stack
][0];
1099 size
= convert_modes (mode
, ptr_mode
, size
, 1);
1101 if (insn_operand_predicate
[(int) CODE_FOR_allocate_stack
][0]
1102 && ! ((*insn_operand_predicate
[(int) CODE_FOR_allocate_stack
][0])
1104 size
= copy_to_mode_reg (mode
, size
);
1106 emit_insn (gen_allocate_stack (size
));
1111 size
= convert_modes (Pmode
, ptr_mode
, size
, 1);
1112 anti_adjust_stack (size
);
1115 #ifdef STACK_GROWS_DOWNWARD
1116 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1121 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1122 but we know it can't. So add ourselves and then do
1124 target
= expand_binop (Pmode
, add_optab
, target
,
1125 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1),
1126 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1127 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1128 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
),
1130 target
= expand_mult (Pmode
, target
,
1131 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
),
1135 /* Some systems require a particular insn to refer to the stack
1136 to make the pages exist. */
1139 emit_insn (gen_probe ());
1142 /* Record the new stack level for nonlocal gotos. */
1143 if (nonlocal_goto_handler_slot
!= 0)
1144 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
, NULL_RTX
);
1149 /* Return an rtx representing the register or memory location
1150 in which a scalar value of data type VALTYPE
1151 was returned by a function call to function FUNC.
1152 FUNC is a FUNCTION_DECL node if the precise function is known,
1156 hard_function_value (valtype
, func
)
1160 rtx val
= FUNCTION_VALUE (valtype
, func
);
1161 if (GET_CODE (val
) == REG
1162 && GET_MODE (val
) == BLKmode
)
1164 int bytes
= int_size_in_bytes (valtype
);
1165 enum machine_mode tmpmode
;
1166 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1167 tmpmode
!= MAX_MACHINE_MODE
;
1168 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1170 /* Have we found a large enough mode? */
1171 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1175 /* No suitable mode found. */
1176 if (tmpmode
== MAX_MACHINE_MODE
)
1179 PUT_MODE (val
, tmpmode
);
1184 /* Return an rtx representing the register or memory location
1185 in which a scalar value of mode MODE was returned by a library call. */
1188 hard_libcall_value (mode
)
1189 enum machine_mode mode
;
1191 return LIBCALL_VALUE (mode
);
1194 /* Look up the tree code for a given rtx code
1195 to provide the arithmetic operation for REAL_ARITHMETIC.
1196 The function returns an int because the caller may not know
1197 what `enum tree_code' means. */
1200 rtx_to_tree_code (code
)
1203 enum tree_code tcode
;
1226 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1229 return ((int) tcode
);