1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987, 91, 94-97, 1998, 1999 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. */
30 #include "hard-reg-set.h"
31 #include "insn-config.h"
33 #include "insn-flags.h"
34 #include "insn-codes.h"
36 #if !defined PREFERRED_STACK_BOUNDARY && defined STACK_BOUNDARY
37 #define PREFERRED_STACK_BOUNDARY STACK_BOUNDARY
40 static rtx break_out_memory_refs
PROTO((rtx
));
41 static void emit_stack_probe
PROTO((rtx
));
44 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
47 trunc_int_for_mode (c
, mode
)
49 enum machine_mode mode
;
51 int width
= GET_MODE_BITSIZE (mode
);
53 /* We clear out all bits that don't belong in MODE, unless they and our
54 sign bit are all one. So we get either a reasonable negative
55 value or a reasonable unsigned value. */
57 if (width
< HOST_BITS_PER_WIDE_INT
58 && ((c
& ((HOST_WIDE_INT
) (-1) << (width
- 1)))
59 != ((HOST_WIDE_INT
) (-1) << (width
- 1))))
60 c
&= ((HOST_WIDE_INT
) 1 << width
) - 1;
62 /* If this would be an entire word for the target, but is not for
63 the host, then sign-extend on the host so that the number will look
64 the same way on the host that it would on the target.
66 For example, when building a 64 bit alpha hosted 32 bit sparc
67 targeted compiler, then we want the 32 bit unsigned value -1 to be
68 represented as a 64 bit value -1, and not as 0x00000000ffffffff.
69 The later confuses the sparc backend. */
71 if (BITS_PER_WORD
< HOST_BITS_PER_WIDE_INT
72 && BITS_PER_WORD
== width
73 && (c
& ((HOST_WIDE_INT
) 1 << (width
- 1))))
74 c
|= ((HOST_WIDE_INT
) (-1) << width
);
79 /* Return an rtx for the sum of X and the integer C.
81 This function should be used via the `plus_constant' macro. */
84 plus_constant_wide (x
, c
)
86 register HOST_WIDE_INT c
;
88 register RTX_CODE code
;
89 register enum machine_mode mode
;
103 return GEN_INT (INTVAL (x
) + c
);
107 HOST_WIDE_INT l1
= CONST_DOUBLE_LOW (x
);
108 HOST_WIDE_INT h1
= CONST_DOUBLE_HIGH (x
);
109 HOST_WIDE_INT l2
= c
;
110 HOST_WIDE_INT h2
= c
< 0 ? ~0 : 0;
111 HOST_WIDE_INT lv
, hv
;
113 add_double (l1
, h1
, l2
, h2
, &lv
, &hv
);
115 return immed_double_const (lv
, hv
, VOIDmode
);
119 /* If this is a reference to the constant pool, try replacing it with
120 a reference to a new constant. If the resulting address isn't
121 valid, don't return it because we have no way to validize it. */
122 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
123 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
125 /* Any rtl we create here must go in a saveable obstack, since
126 we might have been called from within combine. */
127 push_obstacks_nochange ();
128 rtl_in_saveable_obstack ();
130 = force_const_mem (GET_MODE (x
),
131 plus_constant (get_pool_constant (XEXP (x
, 0)),
134 if (memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
140 /* If adding to something entirely constant, set a flag
141 so that we can add a CONST around the result. */
152 /* The interesting case is adding the integer to a sum.
153 Look for constant term in the sum and combine
154 with C. For an integer constant term, we make a combined
155 integer. For a constant term that is not an explicit integer,
156 we cannot really combine, but group them together anyway.
158 Restart or use a recursive call in case the remaining operand is
159 something that we handle specially, such as a SYMBOL_REF.
161 We may not immediately return from the recursive call here, lest
162 all_constant gets lost. */
164 if (GET_CODE (XEXP (x
, 1)) == CONST_INT
)
166 c
+= INTVAL (XEXP (x
, 1));
168 if (GET_MODE (x
) != VOIDmode
)
169 c
= trunc_int_for_mode (c
, GET_MODE (x
));
174 else if (CONSTANT_P (XEXP (x
, 0)))
176 x
= gen_rtx_PLUS (mode
,
177 plus_constant (XEXP (x
, 0), c
),
181 else if (CONSTANT_P (XEXP (x
, 1)))
183 x
= gen_rtx_PLUS (mode
,
185 plus_constant (XEXP (x
, 1), c
));
195 x
= gen_rtx_PLUS (mode
, x
, GEN_INT (c
));
197 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
199 else if (all_constant
)
200 return gen_rtx_CONST (mode
, x
);
205 /* This is the same as `plus_constant', except that it handles LO_SUM.
207 This function should be used via the `plus_constant_for_output' macro. */
210 plus_constant_for_output_wide (x
, c
)
212 register HOST_WIDE_INT c
;
214 register enum machine_mode mode
= GET_MODE (x
);
216 if (GET_CODE (x
) == LO_SUM
)
217 return gen_rtx_LO_SUM (mode
, XEXP (x
, 0),
218 plus_constant_for_output (XEXP (x
, 1), c
));
221 return plus_constant (x
, c
);
224 /* If X is a sum, return a new sum like X but lacking any constant terms.
225 Add all the removed constant terms into *CONSTPTR.
226 X itself is not altered. The result != X if and only if
227 it is not isomorphic to X. */
230 eliminate_constant_term (x
, constptr
)
237 if (GET_CODE (x
) != PLUS
)
240 /* First handle constants appearing at this level explicitly. */
241 if (GET_CODE (XEXP (x
, 1)) == CONST_INT
242 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
244 && GET_CODE (tem
) == CONST_INT
)
247 return eliminate_constant_term (XEXP (x
, 0), constptr
);
251 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
252 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
253 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
254 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
256 && GET_CODE (tem
) == CONST_INT
)
259 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
265 /* Returns the insn that next references REG after INSN, or 0
266 if REG is clobbered before next referenced or we cannot find
267 an insn that references REG in a straight-line piece of code. */
270 find_next_ref (reg
, insn
)
276 for (insn
= NEXT_INSN (insn
); insn
; insn
= next
)
278 next
= NEXT_INSN (insn
);
279 if (GET_CODE (insn
) == NOTE
)
281 if (GET_CODE (insn
) == CODE_LABEL
282 || GET_CODE (insn
) == BARRIER
)
284 if (GET_CODE (insn
) == INSN
285 || GET_CODE (insn
) == JUMP_INSN
286 || GET_CODE (insn
) == CALL_INSN
)
288 if (reg_set_p (reg
, insn
))
290 if (reg_mentioned_p (reg
, PATTERN (insn
)))
292 if (GET_CODE (insn
) == JUMP_INSN
)
294 if (simplejump_p (insn
))
295 next
= JUMP_LABEL (insn
);
299 if (GET_CODE (insn
) == CALL_INSN
300 && REGNO (reg
) < FIRST_PSEUDO_REGISTER
301 && call_used_regs
[REGNO (reg
)])
310 /* Return an rtx for the size in bytes of the value of EXP. */
316 tree size
= size_in_bytes (TREE_TYPE (exp
));
318 if (TREE_CODE (size
) != INTEGER_CST
319 && contains_placeholder_p (size
))
320 size
= build (WITH_RECORD_EXPR
, sizetype
, size
, exp
);
322 return expand_expr (size
, NULL_RTX
, TYPE_MODE (sizetype
),
323 EXPAND_MEMORY_USE_BAD
);
326 /* Return a copy of X in which all memory references
327 and all constants that involve symbol refs
328 have been replaced with new temporary registers.
329 Also emit code to load the memory locations and constants
330 into those registers.
332 If X contains no such constants or memory references,
333 X itself (not a copy) is returned.
335 If a constant is found in the address that is not a legitimate constant
336 in an insn, it is left alone in the hope that it might be valid in the
339 X may contain no arithmetic except addition, subtraction and multiplication.
340 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
343 break_out_memory_refs (x
)
346 if (GET_CODE (x
) == MEM
347 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
348 && GET_MODE (x
) != VOIDmode
))
349 x
= force_reg (GET_MODE (x
), x
);
350 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
351 || GET_CODE (x
) == MULT
)
353 register rtx op0
= break_out_memory_refs (XEXP (x
, 0));
354 register rtx op1
= break_out_memory_refs (XEXP (x
, 1));
356 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
357 x
= gen_rtx_fmt_ee (GET_CODE (x
), Pmode
, op0
, op1
);
363 #ifdef POINTERS_EXTEND_UNSIGNED
365 /* Given X, a memory address in ptr_mode, convert it to an address
366 in Pmode, or vice versa (TO_MODE says which way). We take advantage of
367 the fact that pointers are not allowed to overflow by commuting arithmetic
368 operations over conversions so that address arithmetic insns can be
372 convert_memory_address (to_mode
, x
)
373 enum machine_mode to_mode
;
376 enum machine_mode from_mode
= to_mode
== ptr_mode
? Pmode
: ptr_mode
;
379 /* Here we handle some special cases. If none of them apply, fall through
380 to the default case. */
381 switch (GET_CODE (x
))
388 temp
= gen_rtx_LABEL_REF (to_mode
, XEXP (x
, 0));
389 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
393 temp
= gen_rtx_SYMBOL_REF (to_mode
, XSTR (x
, 0));
394 SYMBOL_REF_FLAG (temp
) = SYMBOL_REF_FLAG (x
);
395 CONSTANT_POOL_ADDRESS_P (temp
) = CONSTANT_POOL_ADDRESS_P (x
);
399 return gen_rtx_CONST (to_mode
,
400 convert_memory_address (to_mode
, XEXP (x
, 0)));
404 /* For addition the second operand is a small constant, we can safely
405 permute the conversion and addition operation. We can always safely
406 permute them if we are making the address narrower. In addition,
407 always permute the operations if this is a constant. */
408 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
409 || (GET_CODE (x
) == PLUS
&& GET_CODE (XEXP (x
, 1)) == CONST_INT
410 && (INTVAL (XEXP (x
, 1)) + 20000 < 40000
411 || CONSTANT_P (XEXP (x
, 0)))))
412 return gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
413 convert_memory_address (to_mode
, XEXP (x
, 0)),
414 convert_memory_address (to_mode
, XEXP (x
, 1)));
421 return convert_modes (to_mode
, from_mode
,
422 x
, POINTERS_EXTEND_UNSIGNED
);
426 /* Given a memory address or facsimile X, construct a new address,
427 currently equivalent, that is stable: future stores won't change it.
429 X must be composed of constants, register and memory references
430 combined with addition, subtraction and multiplication:
431 in other words, just what you can get from expand_expr if sum_ok is 1.
433 Works by making copies of all regs and memory locations used
434 by X and combining them the same way X does.
435 You could also stabilize the reference to this address
436 by copying the address to a register with copy_to_reg;
437 but then you wouldn't get indexed addressing in the reference. */
443 if (GET_CODE (x
) == REG
)
445 if (REGNO (x
) != FRAME_POINTER_REGNUM
446 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
447 && REGNO (x
) != HARD_FRAME_POINTER_REGNUM
452 else if (GET_CODE (x
) == MEM
)
454 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
455 || GET_CODE (x
) == MULT
)
457 register rtx op0
= copy_all_regs (XEXP (x
, 0));
458 register rtx op1
= copy_all_regs (XEXP (x
, 1));
459 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
460 x
= gen_rtx_fmt_ee (GET_CODE (x
), Pmode
, op0
, op1
);
465 /* Return something equivalent to X but valid as a memory address
466 for something of mode MODE. When X is not itself valid, this
467 works by copying X or subexpressions of it into registers. */
470 memory_address (mode
, x
)
471 enum machine_mode mode
;
474 register rtx oldx
= x
;
476 if (GET_CODE (x
) == ADDRESSOF
)
479 #ifdef POINTERS_EXTEND_UNSIGNED
480 if (GET_MODE (x
) == ptr_mode
)
481 x
= convert_memory_address (Pmode
, x
);
484 /* By passing constant addresses thru registers
485 we get a chance to cse them. */
486 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
487 x
= force_reg (Pmode
, x
);
489 /* Accept a QUEUED that refers to a REG
490 even though that isn't a valid address.
491 On attempting to put this in an insn we will call protect_from_queue
492 which will turn it into a REG, which is valid. */
493 else if (GET_CODE (x
) == QUEUED
494 && GET_CODE (QUEUED_VAR (x
)) == REG
)
497 /* We get better cse by rejecting indirect addressing at this stage.
498 Let the combiner create indirect addresses where appropriate.
499 For now, generate the code so that the subexpressions useful to share
500 are visible. But not if cse won't be done! */
503 if (! cse_not_expected
&& GET_CODE (x
) != REG
)
504 x
= break_out_memory_refs (x
);
506 /* At this point, any valid address is accepted. */
507 GO_IF_LEGITIMATE_ADDRESS (mode
, x
, win
);
509 /* If it was valid before but breaking out memory refs invalidated it,
510 use it the old way. */
511 if (memory_address_p (mode
, oldx
))
514 /* Perform machine-dependent transformations on X
515 in certain cases. This is not necessary since the code
516 below can handle all possible cases, but machine-dependent
517 transformations can make better code. */
518 LEGITIMIZE_ADDRESS (x
, oldx
, mode
, win
);
520 /* PLUS and MULT can appear in special ways
521 as the result of attempts to make an address usable for indexing.
522 Usually they are dealt with by calling force_operand, below.
523 But a sum containing constant terms is special
524 if removing them makes the sum a valid address:
525 then we generate that address in a register
526 and index off of it. We do this because it often makes
527 shorter code, and because the addresses thus generated
528 in registers often become common subexpressions. */
529 if (GET_CODE (x
) == PLUS
)
531 rtx constant_term
= const0_rtx
;
532 rtx y
= eliminate_constant_term (x
, &constant_term
);
533 if (constant_term
== const0_rtx
534 || ! memory_address_p (mode
, y
))
535 x
= force_operand (x
, NULL_RTX
);
538 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
539 if (! memory_address_p (mode
, y
))
540 x
= force_operand (x
, NULL_RTX
);
546 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
547 x
= force_operand (x
, NULL_RTX
);
549 /* If we have a register that's an invalid address,
550 it must be a hard reg of the wrong class. Copy it to a pseudo. */
551 else if (GET_CODE (x
) == REG
)
554 /* Last resort: copy the value to a register, since
555 the register is a valid address. */
557 x
= force_reg (Pmode
, x
);
564 if (flag_force_addr
&& ! cse_not_expected
&& GET_CODE (x
) != REG
565 /* Don't copy an addr via a reg if it is one of our stack slots. */
566 && ! (GET_CODE (x
) == PLUS
567 && (XEXP (x
, 0) == virtual_stack_vars_rtx
568 || XEXP (x
, 0) == virtual_incoming_args_rtx
)))
570 if (general_operand (x
, Pmode
))
571 x
= force_reg (Pmode
, x
);
573 x
= force_operand (x
, NULL_RTX
);
579 /* If we didn't change the address, we are done. Otherwise, mark
580 a reg as a pointer if we have REG or REG + CONST_INT. */
583 else if (GET_CODE (x
) == REG
)
584 mark_reg_pointer (x
, 1);
585 else if (GET_CODE (x
) == PLUS
586 && GET_CODE (XEXP (x
, 0)) == REG
587 && GET_CODE (XEXP (x
, 1)) == CONST_INT
)
588 mark_reg_pointer (XEXP (x
, 0), 1);
590 /* OLDX may have been the address on a temporary. Update the address
591 to indicate that X is now used. */
592 update_temp_slot_address (oldx
, x
);
597 /* Like `memory_address' but pretend `flag_force_addr' is 0. */
600 memory_address_noforce (mode
, x
)
601 enum machine_mode mode
;
604 int ambient_force_addr
= flag_force_addr
;
608 val
= memory_address (mode
, x
);
609 flag_force_addr
= ambient_force_addr
;
613 /* Convert a mem ref into one with a valid memory address.
614 Pass through anything else unchanged. */
620 if (GET_CODE (ref
) != MEM
)
622 if (memory_address_p (GET_MODE (ref
), XEXP (ref
, 0)))
624 /* Don't alter REF itself, since that is probably a stack slot. */
625 return change_address (ref
, GET_MODE (ref
), XEXP (ref
, 0));
628 /* Return a modified copy of X with its memory address copied
629 into a temporary register to protect it from side effects.
630 If X is not a MEM, it is returned unchanged (and not copied).
631 Perhaps even if it is a MEM, if there is no need to change it. */
638 if (GET_CODE (x
) != MEM
)
641 if (rtx_unstable_p (addr
))
643 rtx temp
= copy_all_regs (addr
);
645 if (GET_CODE (temp
) != REG
)
646 temp
= copy_to_reg (temp
);
647 mem
= gen_rtx_MEM (GET_MODE (x
), temp
);
649 /* Mark returned memref with in_struct if it's in an array or
650 structure. Copy const and volatile from original memref. */
652 RTX_UNCHANGING_P (mem
) = RTX_UNCHANGING_P (x
);
653 MEM_COPY_ATTRIBUTES (mem
, x
);
654 if (GET_CODE (addr
) == PLUS
)
655 MEM_SET_IN_STRUCT_P (mem
, 1);
657 /* Since the new MEM is just like the old X, it can alias only
658 the things that X could. */
659 MEM_ALIAS_SET (mem
) = MEM_ALIAS_SET (x
);
666 /* Copy the value or contents of X to a new temp reg and return that reg. */
672 register rtx temp
= gen_reg_rtx (GET_MODE (x
));
674 /* If not an operand, must be an address with PLUS and MULT so
675 do the computation. */
676 if (! general_operand (x
, VOIDmode
))
677 x
= force_operand (x
, temp
);
680 emit_move_insn (temp
, x
);
685 /* Like copy_to_reg but always give the new register mode Pmode
686 in case X is a constant. */
692 return copy_to_mode_reg (Pmode
, x
);
695 /* Like copy_to_reg but always give the new register mode MODE
696 in case X is a constant. */
699 copy_to_mode_reg (mode
, x
)
700 enum machine_mode mode
;
703 register rtx temp
= gen_reg_rtx (mode
);
705 /* If not an operand, must be an address with PLUS and MULT so
706 do the computation. */
707 if (! general_operand (x
, VOIDmode
))
708 x
= force_operand (x
, temp
);
710 if (GET_MODE (x
) != mode
&& GET_MODE (x
) != VOIDmode
)
713 emit_move_insn (temp
, x
);
717 /* Load X into a register if it is not already one.
718 Use mode MODE for the register.
719 X should be valid for mode MODE, but it may be a constant which
720 is valid for all integer modes; that's why caller must specify MODE.
722 The caller must not alter the value in the register we return,
723 since we mark it as a "constant" register. */
727 enum machine_mode mode
;
730 register rtx temp
, insn
, set
;
732 if (GET_CODE (x
) == REG
)
735 temp
= gen_reg_rtx (mode
);
737 if (! general_operand (x
, mode
))
738 x
= force_operand (x
, NULL_RTX
);
740 insn
= emit_move_insn (temp
, x
);
742 /* Let optimizers know that TEMP's value never changes
743 and that X can be substituted for it. Don't get confused
744 if INSN set something else (such as a SUBREG of TEMP). */
746 && (set
= single_set (insn
)) != 0
747 && SET_DEST (set
) == temp
)
749 rtx note
= find_reg_note (insn
, REG_EQUAL
, NULL_RTX
);
754 REG_NOTES (insn
) = gen_rtx_EXPR_LIST (REG_EQUAL
, x
, REG_NOTES (insn
));
759 /* If X is a memory ref, copy its contents to a new temp reg and return
760 that reg. Otherwise, return X. */
767 if (GET_CODE (x
) != MEM
|| GET_MODE (x
) == BLKmode
)
769 temp
= gen_reg_rtx (GET_MODE (x
));
770 emit_move_insn (temp
, x
);
774 /* Copy X to TARGET (if it's nonzero and a reg)
775 or to a new temp reg and return that reg.
776 MODE is the mode to use for X in case it is a constant. */
779 copy_to_suggested_reg (x
, target
, mode
)
781 enum machine_mode mode
;
785 if (target
&& GET_CODE (target
) == REG
)
788 temp
= gen_reg_rtx (mode
);
790 emit_move_insn (temp
, x
);
794 /* Return the mode to use to store a scalar of TYPE and MODE.
795 PUNSIGNEDP points to the signedness of the type and may be adjusted
796 to show what signedness to use on extension operations.
798 FOR_CALL is non-zero if this call is promoting args for a call. */
801 promote_mode (type
, mode
, punsignedp
, for_call
)
803 enum machine_mode mode
;
805 int for_call ATTRIBUTE_UNUSED
;
807 enum tree_code code
= TREE_CODE (type
);
808 int unsignedp
= *punsignedp
;
810 #ifdef PROMOTE_FOR_CALL_ONLY
818 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
819 case CHAR_TYPE
: case REAL_TYPE
: case OFFSET_TYPE
:
820 PROMOTE_MODE (mode
, unsignedp
, type
);
824 #ifdef POINTERS_EXTEND_UNSIGNED
828 unsignedp
= POINTERS_EXTEND_UNSIGNED
;
836 *punsignedp
= unsignedp
;
840 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
841 This pops when ADJUST is positive. ADJUST need not be constant. */
844 adjust_stack (adjust
)
848 adjust
= protect_from_queue (adjust
, 0);
850 if (adjust
== const0_rtx
)
853 temp
= expand_binop (Pmode
,
854 #ifdef STACK_GROWS_DOWNWARD
859 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
862 if (temp
!= stack_pointer_rtx
)
863 emit_move_insn (stack_pointer_rtx
, temp
);
866 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
867 This pushes when ADJUST is positive. ADJUST need not be constant. */
870 anti_adjust_stack (adjust
)
874 adjust
= protect_from_queue (adjust
, 0);
876 if (adjust
== const0_rtx
)
879 temp
= expand_binop (Pmode
,
880 #ifdef STACK_GROWS_DOWNWARD
885 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
888 if (temp
!= stack_pointer_rtx
)
889 emit_move_insn (stack_pointer_rtx
, temp
);
892 /* Round the size of a block to be pushed up to the boundary required
893 by this machine. SIZE is the desired size, which need not be constant. */
899 #ifdef PREFERRED_STACK_BOUNDARY
900 int align
= PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
;
903 if (GET_CODE (size
) == CONST_INT
)
905 int new = (INTVAL (size
) + align
- 1) / align
* align
;
906 if (INTVAL (size
) != new)
907 size
= GEN_INT (new);
911 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
912 but we know it can't. So add ourselves and then do
914 size
= expand_binop (Pmode
, add_optab
, size
, GEN_INT (align
- 1),
915 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
916 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, GEN_INT (align
),
918 size
= expand_mult (Pmode
, size
, GEN_INT (align
), NULL_RTX
, 1);
920 #endif /* PREFERRED_STACK_BOUNDARY */
924 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
925 to a previously-created save area. If no save area has been allocated,
926 this function will allocate one. If a save area is specified, it
927 must be of the proper mode.
929 The insns are emitted after insn AFTER, if nonzero, otherwise the insns
930 are emitted at the current position. */
933 emit_stack_save (save_level
, psave
, after
)
934 enum save_level save_level
;
939 /* The default is that we use a move insn and save in a Pmode object. */
940 rtx (*fcn
) PROTO ((rtx
, rtx
)) = gen_move_insn
;
941 enum machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
943 /* See if this machine has anything special to do for this kind of save. */
946 #ifdef HAVE_save_stack_block
948 if (HAVE_save_stack_block
)
949 fcn
= gen_save_stack_block
;
952 #ifdef HAVE_save_stack_function
954 if (HAVE_save_stack_function
)
955 fcn
= gen_save_stack_function
;
958 #ifdef HAVE_save_stack_nonlocal
960 if (HAVE_save_stack_nonlocal
)
961 fcn
= gen_save_stack_nonlocal
;
968 /* If there is no save area and we have to allocate one, do so. Otherwise
969 verify the save area is the proper mode. */
973 if (mode
!= VOIDmode
)
975 if (save_level
== SAVE_NONLOCAL
)
976 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
978 *psave
= sa
= gen_reg_rtx (mode
);
983 if (mode
== VOIDmode
|| GET_MODE (sa
) != mode
)
992 /* We must validize inside the sequence, to ensure that any instructions
993 created by the validize call also get moved to the right place. */
995 sa
= validize_mem (sa
);
996 emit_insn (fcn (sa
, stack_pointer_rtx
));
997 seq
= gen_sequence ();
999 emit_insn_after (seq
, after
);
1004 sa
= validize_mem (sa
);
1005 emit_insn (fcn (sa
, stack_pointer_rtx
));
1009 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1010 area made by emit_stack_save. If it is zero, we have nothing to do.
1012 Put any emitted insns after insn AFTER, if nonzero, otherwise at
1013 current position. */
1016 emit_stack_restore (save_level
, sa
, after
)
1017 enum save_level save_level
;
1021 /* The default is that we use a move insn. */
1022 rtx (*fcn
) PROTO ((rtx
, rtx
)) = gen_move_insn
;
1024 /* See if this machine has anything special to do for this kind of save. */
1027 #ifdef HAVE_restore_stack_block
1029 if (HAVE_restore_stack_block
)
1030 fcn
= gen_restore_stack_block
;
1033 #ifdef HAVE_restore_stack_function
1035 if (HAVE_restore_stack_function
)
1036 fcn
= gen_restore_stack_function
;
1039 #ifdef HAVE_restore_stack_nonlocal
1041 if (HAVE_restore_stack_nonlocal
)
1042 fcn
= gen_restore_stack_nonlocal
;
1050 sa
= validize_mem (sa
);
1057 emit_insn (fcn (stack_pointer_rtx
, sa
));
1058 seq
= gen_sequence ();
1060 emit_insn_after (seq
, after
);
1063 emit_insn (fcn (stack_pointer_rtx
, sa
));
1066 #ifdef SETJMP_VIA_SAVE_AREA
1067 /* Optimize RTL generated by allocate_dynamic_stack_space for targets
1068 where SETJMP_VIA_SAVE_AREA is true. The problem is that on these
1069 platforms, the dynamic stack space used can corrupt the original
1070 frame, thus causing a crash if a longjmp unwinds to it. */
1073 optimize_save_area_alloca (insns
)
1078 for (insn
= insns
; insn
; insn
= NEXT_INSN(insn
))
1082 if (GET_CODE (insn
) != INSN
)
1085 for (note
= REG_NOTES (insn
); note
; note
= XEXP (note
, 1))
1087 if (REG_NOTE_KIND (note
) != REG_SAVE_AREA
)
1090 if (!current_function_calls_setjmp
)
1092 rtx pat
= PATTERN (insn
);
1094 /* If we do not see the note in a pattern matching
1095 these precise characteristics, we did something
1096 entirely wrong in allocate_dynamic_stack_space.
1098 Note, one way this could happen is if SETJMP_VIA_SAVE_AREA
1099 was defined on a machine where stacks grow towards higher
1102 Right now only supported port with stack that grow upward
1103 is the HPPA and it does not define SETJMP_VIA_SAVE_AREA. */
1104 if (GET_CODE (pat
) != SET
1105 || SET_DEST (pat
) != stack_pointer_rtx
1106 || GET_CODE (SET_SRC (pat
)) != MINUS
1107 || XEXP (SET_SRC (pat
), 0) != stack_pointer_rtx
)
1110 /* This will now be transformed into a (set REG REG)
1111 so we can just blow away all the other notes. */
1112 XEXP (SET_SRC (pat
), 1) = XEXP (note
, 0);
1113 REG_NOTES (insn
) = NULL_RTX
;
1117 /* setjmp was called, we must remove the REG_SAVE_AREA
1118 note so that later passes do not get confused by its
1120 if (note
== REG_NOTES (insn
))
1122 REG_NOTES (insn
) = XEXP (note
, 1);
1128 for (srch
= REG_NOTES (insn
); srch
; srch
= XEXP (srch
, 1))
1129 if (XEXP (srch
, 1) == note
)
1132 if (srch
== NULL_RTX
)
1135 XEXP (srch
, 1) = XEXP (note
, 1);
1138 /* Once we've seen the note of interest, we need not look at
1139 the rest of them. */
1144 #endif /* SETJMP_VIA_SAVE_AREA */
1146 /* Return an rtx representing the address of an area of memory dynamically
1147 pushed on the stack. This region of memory is always aligned to
1148 a multiple of BIGGEST_ALIGNMENT.
1150 Any required stack pointer alignment is preserved.
1152 SIZE is an rtx representing the size of the area.
1153 TARGET is a place in which the address can be placed.
1155 KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */
1158 allocate_dynamic_stack_space (size
, target
, known_align
)
1163 #ifdef SETJMP_VIA_SAVE_AREA
1164 rtx setjmpless_size
= NULL_RTX
;
1167 /* If we're asking for zero bytes, it doesn't matter what we point
1168 to since we can't dereference it. But return a reasonable
1170 if (size
== const0_rtx
)
1171 return virtual_stack_dynamic_rtx
;
1173 /* Otherwise, show we're calling alloca or equivalent. */
1174 current_function_calls_alloca
= 1;
1176 /* Ensure the size is in the proper mode. */
1177 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1178 size
= convert_to_mode (Pmode
, size
, 1);
1180 /* We will need to ensure that the address we return is aligned to
1181 BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
1182 always know its final value at this point in the compilation (it
1183 might depend on the size of the outgoing parameter lists, for
1184 example), so we must align the value to be returned in that case.
1185 (Note that STACK_DYNAMIC_OFFSET will have a default non-zero value if
1186 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1187 We must also do an alignment operation on the returned value if
1188 the stack pointer alignment is less strict that BIGGEST_ALIGNMENT.
1190 If we have to align, we must leave space in SIZE for the hole
1191 that might result from the alignment operation. */
1193 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET) || ! defined (PREFERRED_STACK_BOUNDARY)
1194 #define MUST_ALIGN 1
1196 #define MUST_ALIGN (PREFERRED_STACK_BOUNDARY < BIGGEST_ALIGNMENT)
1201 if (GET_CODE (size
) == CONST_INT
)
1202 size
= GEN_INT (INTVAL (size
)
1203 + (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1));
1205 size
= expand_binop (Pmode
, add_optab
, size
,
1206 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1),
1207 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1210 #ifdef SETJMP_VIA_SAVE_AREA
1211 /* If setjmp restores regs from a save area in the stack frame,
1212 avoid clobbering the reg save area. Note that the offset of
1213 virtual_incoming_args_rtx includes the preallocated stack args space.
1214 It would be no problem to clobber that, but it's on the wrong side
1215 of the old save area. */
1218 = expand_binop (Pmode
, sub_optab
, virtual_stack_dynamic_rtx
,
1219 stack_pointer_rtx
, NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1221 if (!current_function_calls_setjmp
)
1223 int align
= PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
;
1225 /* See optimize_save_area_alloca to understand what is being
1228 #if !defined(PREFERRED_STACK_BOUNDARY) || !defined(MUST_ALIGN) || (PREFERRED_STACK_BOUNDARY != BIGGEST_ALIGNMENT)
1229 /* If anyone creates a target with these characteristics, let them
1230 know that our optimization cannot work correctly in such a case. */
1234 if (GET_CODE (size
) == CONST_INT
)
1236 int new = INTVAL (size
) / align
* align
;
1238 if (INTVAL (size
) != new)
1239 setjmpless_size
= GEN_INT (new);
1241 setjmpless_size
= size
;
1245 /* Since we know overflow is not possible, we avoid using
1246 CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */
1247 setjmpless_size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
,
1248 GEN_INT (align
), NULL_RTX
, 1);
1249 setjmpless_size
= expand_mult (Pmode
, setjmpless_size
,
1250 GEN_INT (align
), NULL_RTX
, 1);
1252 /* Our optimization works based upon being able to perform a simple
1253 transformation of this RTL into a (set REG REG) so make sure things
1254 did in fact end up in a REG. */
1255 if (!register_operand (setjmpless_size
, Pmode
))
1256 setjmpless_size
= force_reg (Pmode
, setjmpless_size
);
1259 size
= expand_binop (Pmode
, add_optab
, size
, dynamic_offset
,
1260 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1262 #endif /* SETJMP_VIA_SAVE_AREA */
1264 /* Round the size to a multiple of the required stack alignment.
1265 Since the stack if presumed to be rounded before this allocation,
1266 this will maintain the required alignment.
1268 If the stack grows downward, we could save an insn by subtracting
1269 SIZE from the stack pointer and then aligning the stack pointer.
1270 The problem with this is that the stack pointer may be unaligned
1271 between the execution of the subtraction and alignment insns and
1272 some machines do not allow this. Even on those that do, some
1273 signal handlers malfunction if a signal should occur between those
1274 insns. Since this is an extremely rare event, we have no reliable
1275 way of knowing which systems have this problem. So we avoid even
1276 momentarily mis-aligning the stack. */
1278 #ifdef PREFERRED_STACK_BOUNDARY
1279 /* If we added a variable amount to SIZE,
1280 we can no longer assume it is aligned. */
1281 #if !defined (SETJMP_VIA_SAVE_AREA)
1282 if (MUST_ALIGN
|| known_align
% PREFERRED_STACK_BOUNDARY
!= 0)
1284 size
= round_push (size
);
1287 do_pending_stack_adjust ();
1289 /* If needed, check that we have the required amount of stack. Take into
1290 account what has already been checked. */
1291 if (flag_stack_check
&& ! STACK_CHECK_BUILTIN
)
1292 probe_stack_range (STACK_CHECK_MAX_FRAME_SIZE
+ STACK_CHECK_PROTECT
, size
);
1294 /* Don't use a TARGET that isn't a pseudo. */
1295 if (target
== 0 || GET_CODE (target
) != REG
1296 || REGNO (target
) < FIRST_PSEUDO_REGISTER
)
1297 target
= gen_reg_rtx (Pmode
);
1299 mark_reg_pointer (target
, known_align
/ BITS_PER_UNIT
);
1301 /* Perform the required allocation from the stack. Some systems do
1302 this differently than simply incrementing/decrementing from the
1303 stack pointer, such as acquiring the space by calling malloc(). */
1304 #ifdef HAVE_allocate_stack
1305 if (HAVE_allocate_stack
)
1307 enum machine_mode mode
= STACK_SIZE_MODE
;
1309 if (insn_operand_predicate
[(int) CODE_FOR_allocate_stack
][0]
1310 && ! ((*insn_operand_predicate
[(int) CODE_FOR_allocate_stack
][0])
1312 #ifdef POINTERS_EXTEND_UNSIGNED
1313 target
= convert_memory_address (Pmode
, target
);
1315 target
= copy_to_mode_reg (Pmode
, target
);
1318 if (mode
== VOIDmode
)
1321 size
= convert_modes (mode
, ptr_mode
, size
, 1);
1322 if (insn_operand_predicate
[(int) CODE_FOR_allocate_stack
][1]
1323 && ! ((*insn_operand_predicate
[(int) CODE_FOR_allocate_stack
][1])
1325 size
= copy_to_mode_reg (mode
, size
);
1327 emit_insn (gen_allocate_stack (target
, size
));
1332 #ifndef STACK_GROWS_DOWNWARD
1333 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1335 size
= convert_modes (Pmode
, ptr_mode
, size
, 1);
1336 anti_adjust_stack (size
);
1337 #ifdef SETJMP_VIA_SAVE_AREA
1338 if (setjmpless_size
!= NULL_RTX
)
1340 rtx note_target
= get_last_insn ();
1342 REG_NOTES (note_target
)
1343 = gen_rtx_EXPR_LIST (REG_SAVE_AREA
, setjmpless_size
,
1344 REG_NOTES (note_target
));
1346 #endif /* SETJMP_VIA_SAVE_AREA */
1347 #ifdef STACK_GROWS_DOWNWARD
1348 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1354 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1355 but we know it can't. So add ourselves and then do
1357 target
= expand_binop (Pmode
, add_optab
, target
,
1358 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1),
1359 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1360 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1361 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
),
1363 target
= expand_mult (Pmode
, target
,
1364 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
),
1368 /* Some systems require a particular insn to refer to the stack
1369 to make the pages exist. */
1372 emit_insn (gen_probe ());
1375 /* Record the new stack level for nonlocal gotos. */
1376 if (nonlocal_goto_handler_slots
!= 0)
1377 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
, NULL_RTX
);
1382 /* Emit one stack probe at ADDRESS, an address within the stack. */
1385 emit_stack_probe (address
)
1388 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1390 MEM_VOLATILE_P (memref
) = 1;
1392 if (STACK_CHECK_PROBE_LOAD
)
1393 emit_move_insn (gen_reg_rtx (word_mode
), memref
);
1395 emit_move_insn (memref
, const0_rtx
);
1398 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1399 FIRST is a constant and size is a Pmode RTX. These are offsets from the
1400 current stack pointer. STACK_GROWS_DOWNWARD says whether to add or
1401 subtract from the stack. If SIZE is constant, this is done
1402 with a fixed number of probes. Otherwise, we must make a loop. */
1404 #ifdef STACK_GROWS_DOWNWARD
1405 #define STACK_GROW_OP MINUS
1407 #define STACK_GROW_OP PLUS
1411 probe_stack_range (first
, size
)
1412 HOST_WIDE_INT first
;
1415 /* First see if we have an insn to check the stack. Use it if so. */
1416 #ifdef HAVE_check_stack
1417 if (HAVE_check_stack
)
1420 = force_operand (gen_rtx_STACK_GROW_OP (Pmode
,
1422 plus_constant (size
, first
)),
1425 if (insn_operand_predicate
[(int) CODE_FOR_check_stack
][0]
1426 && ! ((*insn_operand_predicate
[(int) CODE_FOR_check_stack
][0])
1427 (last_addr
, Pmode
)))
1428 last_addr
= copy_to_mode_reg (Pmode
, last_addr
);
1430 emit_insn (gen_check_stack (last_addr
));
1435 /* If we have to generate explicit probes, see if we have a constant
1436 small number of them to generate. If so, that's the easy case. */
1437 if (GET_CODE (size
) == CONST_INT
1438 && INTVAL (size
) < 10 * STACK_CHECK_PROBE_INTERVAL
)
1440 HOST_WIDE_INT offset
;
1442 /* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL
1443 for values of N from 1 until it exceeds LAST. If only one
1444 probe is needed, this will not generate any code. Then probe
1446 for (offset
= first
+ STACK_CHECK_PROBE_INTERVAL
;
1447 offset
< INTVAL (size
);
1448 offset
= offset
+ STACK_CHECK_PROBE_INTERVAL
)
1449 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1453 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1455 plus_constant (size
, first
)));
1458 /* In the variable case, do the same as above, but in a loop. We emit loop
1459 notes so that loop optimization can be done. */
1463 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1465 GEN_INT (first
+ STACK_CHECK_PROBE_INTERVAL
)),
1468 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1470 plus_constant (size
, first
)),
1472 rtx incr
= GEN_INT (STACK_CHECK_PROBE_INTERVAL
);
1473 rtx loop_lab
= gen_label_rtx ();
1474 rtx test_lab
= gen_label_rtx ();
1475 rtx end_lab
= gen_label_rtx ();
1478 if (GET_CODE (test_addr
) != REG
1479 || REGNO (test_addr
) < FIRST_PSEUDO_REGISTER
)
1480 test_addr
= force_reg (Pmode
, test_addr
);
1482 emit_note (NULL_PTR
, NOTE_INSN_LOOP_BEG
);
1483 emit_jump (test_lab
);
1485 emit_label (loop_lab
);
1486 emit_stack_probe (test_addr
);
1488 emit_note (NULL_PTR
, NOTE_INSN_LOOP_CONT
);
1490 #ifdef STACK_GROWS_DOWNWARD
1491 #define CMP_OPCODE GTU
1492 temp
= expand_binop (Pmode
, sub_optab
, test_addr
, incr
, test_addr
,
1495 #define CMP_OPCODE LTU
1496 temp
= expand_binop (Pmode
, add_optab
, test_addr
, incr
, test_addr
,
1500 if (temp
!= test_addr
)
1503 emit_label (test_lab
);
1504 emit_cmp_and_jump_insns (test_addr
, last_addr
, CMP_OPCODE
,
1505 NULL_RTX
, Pmode
, 1, 0, loop_lab
);
1506 emit_jump (end_lab
);
1507 emit_note (NULL_PTR
, NOTE_INSN_LOOP_END
);
1508 emit_label (end_lab
);
1510 /* If will be doing stupid optimization, show test_addr is still live. */
1512 emit_insn (gen_rtx_USE (VOIDmode
, test_addr
));
1514 emit_stack_probe (last_addr
);
1518 /* Return an rtx representing the register or memory location
1519 in which a scalar value of data type VALTYPE
1520 was returned by a function call to function FUNC.
1521 FUNC is a FUNCTION_DECL node if the precise function is known,
1525 hard_function_value (valtype
, func
)
1527 tree func ATTRIBUTE_UNUSED
;
1529 rtx val
= FUNCTION_VALUE (valtype
, func
);
1530 if (GET_CODE (val
) == REG
1531 && GET_MODE (val
) == BLKmode
)
1533 int bytes
= int_size_in_bytes (valtype
);
1534 enum machine_mode tmpmode
;
1535 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1536 tmpmode
!= VOIDmode
;
1537 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1539 /* Have we found a large enough mode? */
1540 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1544 /* No suitable mode found. */
1545 if (tmpmode
== VOIDmode
)
1548 PUT_MODE (val
, tmpmode
);
1553 /* Return an rtx representing the register or memory location
1554 in which a scalar value of mode MODE was returned by a library call. */
1557 hard_libcall_value (mode
)
1558 enum machine_mode mode
;
1560 return LIBCALL_VALUE (mode
);
1563 /* Look up the tree code for a given rtx code
1564 to provide the arithmetic operation for REAL_ARITHMETIC.
1565 The function returns an int because the caller may not know
1566 what `enum tree_code' means. */
1569 rtx_to_tree_code (code
)
1572 enum tree_code tcode
;
1595 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1598 return ((int) tcode
);