1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987, 1991, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
32 #include "hard-reg-set.h"
33 #include "insn-config.h"
35 #include "insn-flags.h"
36 #include "insn-codes.h"
38 #if !defined PREFERRED_STACK_BOUNDARY && defined STACK_BOUNDARY
39 #define PREFERRED_STACK_BOUNDARY STACK_BOUNDARY
42 static rtx break_out_memory_refs
PARAMS ((rtx
));
43 static void emit_stack_probe
PARAMS ((rtx
));
46 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
49 trunc_int_for_mode (c
, mode
)
51 enum machine_mode mode
;
53 int width
= GET_MODE_BITSIZE (mode
);
55 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
57 return c
& 1 ? STORE_FLAG_VALUE
: 0;
59 /* We clear out all bits that don't belong in MODE, unless they and our
60 sign bit are all one. So we get either a reasonable negative
61 value or a reasonable unsigned value. */
63 if (width
< HOST_BITS_PER_WIDE_INT
64 && ((c
& ((HOST_WIDE_INT
) (-1) << (width
- 1)))
65 != ((HOST_WIDE_INT
) (-1) << (width
- 1))))
66 c
&= ((HOST_WIDE_INT
) 1 << width
) - 1;
68 /* If this would be an entire word for the target, but is not for
69 the host, then sign-extend on the host so that the number will look
70 the same way on the host that it would on the target.
72 For example, when building a 64 bit alpha hosted 32 bit sparc
73 targeted compiler, then we want the 32 bit unsigned value -1 to be
74 represented as a 64 bit value -1, and not as 0x00000000ffffffff.
75 The later confuses the sparc backend. */
77 if (BITS_PER_WORD
< HOST_BITS_PER_WIDE_INT
78 && BITS_PER_WORD
== width
79 && (c
& ((HOST_WIDE_INT
) 1 << (width
- 1))))
80 c
|= ((HOST_WIDE_INT
) (-1) << width
);
85 /* Return an rtx for the sum of X and the integer C.
87 This function should be used via the `plus_constant' macro. */
90 plus_constant_wide (x
, c
)
92 register HOST_WIDE_INT c
;
94 register RTX_CODE code
;
95 register enum machine_mode mode
;
109 return GEN_INT (INTVAL (x
) + c
);
113 unsigned HOST_WIDE_INT l1
= CONST_DOUBLE_LOW (x
);
114 HOST_WIDE_INT h1
= CONST_DOUBLE_HIGH (x
);
115 unsigned HOST_WIDE_INT l2
= c
;
116 HOST_WIDE_INT h2
= c
< 0 ? ~0 : 0;
117 unsigned HOST_WIDE_INT lv
;
120 add_double (l1
, h1
, l2
, h2
, &lv
, &hv
);
122 return immed_double_const (lv
, hv
, VOIDmode
);
126 /* If this is a reference to the constant pool, try replacing it with
127 a reference to a new constant. If the resulting address isn't
128 valid, don't return it because we have no way to validize it. */
129 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
130 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
132 /* Any rtl we create here must go in a saveable obstack, since
133 we might have been called from within combine. */
134 push_obstacks_nochange ();
135 rtl_in_saveable_obstack ();
137 = force_const_mem (GET_MODE (x
),
138 plus_constant (get_pool_constant (XEXP (x
, 0)),
141 if (memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
147 /* If adding to something entirely constant, set a flag
148 so that we can add a CONST around the result. */
159 /* The interesting case is adding the integer to a sum.
160 Look for constant term in the sum and combine
161 with C. For an integer constant term, we make a combined
162 integer. For a constant term that is not an explicit integer,
163 we cannot really combine, but group them together anyway.
165 Restart or use a recursive call in case the remaining operand is
166 something that we handle specially, such as a SYMBOL_REF.
168 We may not immediately return from the recursive call here, lest
169 all_constant gets lost. */
171 if (GET_CODE (XEXP (x
, 1)) == CONST_INT
)
173 c
+= INTVAL (XEXP (x
, 1));
175 if (GET_MODE (x
) != VOIDmode
)
176 c
= trunc_int_for_mode (c
, GET_MODE (x
));
181 else if (CONSTANT_P (XEXP (x
, 0)))
183 x
= gen_rtx_PLUS (mode
,
184 plus_constant (XEXP (x
, 0), c
),
188 else if (CONSTANT_P (XEXP (x
, 1)))
190 x
= gen_rtx_PLUS (mode
,
192 plus_constant (XEXP (x
, 1), c
));
202 x
= gen_rtx_PLUS (mode
, x
, GEN_INT (c
));
204 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
206 else if (all_constant
)
207 return gen_rtx_CONST (mode
, x
);
212 /* This is the same as `plus_constant', except that it handles LO_SUM.
214 This function should be used via the `plus_constant_for_output' macro. */
217 plus_constant_for_output_wide (x
, c
)
219 register HOST_WIDE_INT c
;
221 register enum machine_mode mode
= GET_MODE (x
);
223 if (GET_CODE (x
) == LO_SUM
)
224 return gen_rtx_LO_SUM (mode
, XEXP (x
, 0),
225 plus_constant_for_output (XEXP (x
, 1), c
));
228 return plus_constant (x
, c
);
231 /* If X is a sum, return a new sum like X but lacking any constant terms.
232 Add all the removed constant terms into *CONSTPTR.
233 X itself is not altered. The result != X if and only if
234 it is not isomorphic to X. */
237 eliminate_constant_term (x
, constptr
)
244 if (GET_CODE (x
) != PLUS
)
247 /* First handle constants appearing at this level explicitly. */
248 if (GET_CODE (XEXP (x
, 1)) == CONST_INT
249 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
251 && GET_CODE (tem
) == CONST_INT
)
254 return eliminate_constant_term (XEXP (x
, 0), constptr
);
258 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
259 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
260 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
261 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
263 && GET_CODE (tem
) == CONST_INT
)
266 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
272 /* Returns the insn that next references REG after INSN, or 0
273 if REG is clobbered before next referenced or we cannot find
274 an insn that references REG in a straight-line piece of code. */
277 find_next_ref (reg
, insn
)
283 for (insn
= NEXT_INSN (insn
); insn
; insn
= next
)
285 next
= NEXT_INSN (insn
);
286 if (GET_CODE (insn
) == NOTE
)
288 if (GET_CODE (insn
) == CODE_LABEL
289 || GET_CODE (insn
) == BARRIER
)
291 if (GET_CODE (insn
) == INSN
292 || GET_CODE (insn
) == JUMP_INSN
293 || GET_CODE (insn
) == CALL_INSN
)
295 if (reg_set_p (reg
, insn
))
297 if (reg_mentioned_p (reg
, PATTERN (insn
)))
299 if (GET_CODE (insn
) == JUMP_INSN
)
301 if (any_uncondjump_p (insn
))
302 next
= JUMP_LABEL (insn
);
306 if (GET_CODE (insn
) == CALL_INSN
307 && REGNO (reg
) < FIRST_PSEUDO_REGISTER
308 && call_used_regs
[REGNO (reg
)])
317 /* Return an rtx for the size in bytes of the value of EXP. */
323 tree size
= size_in_bytes (TREE_TYPE (exp
));
325 if (TREE_CODE (size
) != INTEGER_CST
326 && contains_placeholder_p (size
))
327 size
= build (WITH_RECORD_EXPR
, sizetype
, size
, exp
);
329 return expand_expr (size
, NULL_RTX
, TYPE_MODE (sizetype
),
330 EXPAND_MEMORY_USE_BAD
);
333 /* Return a copy of X in which all memory references
334 and all constants that involve symbol refs
335 have been replaced with new temporary registers.
336 Also emit code to load the memory locations and constants
337 into those registers.
339 If X contains no such constants or memory references,
340 X itself (not a copy) is returned.
342 If a constant is found in the address that is not a legitimate constant
343 in an insn, it is left alone in the hope that it might be valid in the
346 X may contain no arithmetic except addition, subtraction and multiplication.
347 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
350 break_out_memory_refs (x
)
353 if (GET_CODE (x
) == MEM
354 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
355 && GET_MODE (x
) != VOIDmode
))
356 x
= force_reg (GET_MODE (x
), x
);
357 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
358 || GET_CODE (x
) == MULT
)
360 register rtx op0
= break_out_memory_refs (XEXP (x
, 0));
361 register rtx op1
= break_out_memory_refs (XEXP (x
, 1));
363 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
364 x
= gen_rtx_fmt_ee (GET_CODE (x
), Pmode
, op0
, op1
);
370 #ifdef POINTERS_EXTEND_UNSIGNED
372 /* Given X, a memory address in ptr_mode, convert it to an address
373 in Pmode, or vice versa (TO_MODE says which way). We take advantage of
374 the fact that pointers are not allowed to overflow by commuting arithmetic
375 operations over conversions so that address arithmetic insns can be
379 convert_memory_address (to_mode
, x
)
380 enum machine_mode to_mode
;
383 enum machine_mode from_mode
= to_mode
== ptr_mode
? Pmode
: ptr_mode
;
386 /* Here we handle some special cases. If none of them apply, fall through
387 to the default case. */
388 switch (GET_CODE (x
))
395 temp
= gen_rtx_LABEL_REF (to_mode
, XEXP (x
, 0));
396 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
400 temp
= gen_rtx_SYMBOL_REF (to_mode
, XSTR (x
, 0));
401 SYMBOL_REF_FLAG (temp
) = SYMBOL_REF_FLAG (x
);
402 CONSTANT_POOL_ADDRESS_P (temp
) = CONSTANT_POOL_ADDRESS_P (x
);
406 return gen_rtx_CONST (to_mode
,
407 convert_memory_address (to_mode
, XEXP (x
, 0)));
411 /* For addition the second operand is a small constant, we can safely
412 permute the conversion and addition operation. We can always safely
413 permute them if we are making the address narrower. In addition,
414 always permute the operations if this is a constant. */
415 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
416 || (GET_CODE (x
) == PLUS
&& GET_CODE (XEXP (x
, 1)) == CONST_INT
417 && (INTVAL (XEXP (x
, 1)) + 20000 < 40000
418 || CONSTANT_P (XEXP (x
, 0)))))
419 return gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
420 convert_memory_address (to_mode
, XEXP (x
, 0)),
421 convert_memory_address (to_mode
, XEXP (x
, 1)));
428 return convert_modes (to_mode
, from_mode
,
429 x
, POINTERS_EXTEND_UNSIGNED
);
433 /* Given a memory address or facsimile X, construct a new address,
434 currently equivalent, that is stable: future stores won't change it.
436 X must be composed of constants, register and memory references
437 combined with addition, subtraction and multiplication:
438 in other words, just what you can get from expand_expr if sum_ok is 1.
440 Works by making copies of all regs and memory locations used
441 by X and combining them the same way X does.
442 You could also stabilize the reference to this address
443 by copying the address to a register with copy_to_reg;
444 but then you wouldn't get indexed addressing in the reference. */
450 if (GET_CODE (x
) == REG
)
452 if (REGNO (x
) != FRAME_POINTER_REGNUM
453 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
454 && REGNO (x
) != HARD_FRAME_POINTER_REGNUM
459 else if (GET_CODE (x
) == MEM
)
461 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
462 || GET_CODE (x
) == MULT
)
464 register rtx op0
= copy_all_regs (XEXP (x
, 0));
465 register rtx op1
= copy_all_regs (XEXP (x
, 1));
466 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
467 x
= gen_rtx_fmt_ee (GET_CODE (x
), Pmode
, op0
, op1
);
472 /* Return something equivalent to X but valid as a memory address
473 for something of mode MODE. When X is not itself valid, this
474 works by copying X or subexpressions of it into registers. */
477 memory_address (mode
, x
)
478 enum machine_mode mode
;
481 register rtx oldx
= x
;
483 if (GET_CODE (x
) == ADDRESSOF
)
486 #ifdef POINTERS_EXTEND_UNSIGNED
487 if (GET_MODE (x
) == ptr_mode
)
488 x
= convert_memory_address (Pmode
, x
);
491 /* By passing constant addresses thru registers
492 we get a chance to cse them. */
493 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
494 x
= force_reg (Pmode
, x
);
496 /* Accept a QUEUED that refers to a REG
497 even though that isn't a valid address.
498 On attempting to put this in an insn we will call protect_from_queue
499 which will turn it into a REG, which is valid. */
500 else if (GET_CODE (x
) == QUEUED
501 && GET_CODE (QUEUED_VAR (x
)) == REG
)
504 /* We get better cse by rejecting indirect addressing at this stage.
505 Let the combiner create indirect addresses where appropriate.
506 For now, generate the code so that the subexpressions useful to share
507 are visible. But not if cse won't be done! */
510 if (! cse_not_expected
&& GET_CODE (x
) != REG
)
511 x
= break_out_memory_refs (x
);
513 /* At this point, any valid address is accepted. */
514 GO_IF_LEGITIMATE_ADDRESS (mode
, x
, win
);
516 /* If it was valid before but breaking out memory refs invalidated it,
517 use it the old way. */
518 if (memory_address_p (mode
, oldx
))
521 /* Perform machine-dependent transformations on X
522 in certain cases. This is not necessary since the code
523 below can handle all possible cases, but machine-dependent
524 transformations can make better code. */
525 LEGITIMIZE_ADDRESS (x
, oldx
, mode
, win
);
527 /* PLUS and MULT can appear in special ways
528 as the result of attempts to make an address usable for indexing.
529 Usually they are dealt with by calling force_operand, below.
530 But a sum containing constant terms is special
531 if removing them makes the sum a valid address:
532 then we generate that address in a register
533 and index off of it. We do this because it often makes
534 shorter code, and because the addresses thus generated
535 in registers often become common subexpressions. */
536 if (GET_CODE (x
) == PLUS
)
538 rtx constant_term
= const0_rtx
;
539 rtx y
= eliminate_constant_term (x
, &constant_term
);
540 if (constant_term
== const0_rtx
541 || ! memory_address_p (mode
, y
))
542 x
= force_operand (x
, NULL_RTX
);
545 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
546 if (! memory_address_p (mode
, y
))
547 x
= force_operand (x
, NULL_RTX
);
553 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
554 x
= force_operand (x
, NULL_RTX
);
556 /* If we have a register that's an invalid address,
557 it must be a hard reg of the wrong class. Copy it to a pseudo. */
558 else if (GET_CODE (x
) == REG
)
561 /* Last resort: copy the value to a register, since
562 the register is a valid address. */
564 x
= force_reg (Pmode
, x
);
571 if (flag_force_addr
&& ! cse_not_expected
&& GET_CODE (x
) != REG
572 /* Don't copy an addr via a reg if it is one of our stack slots. */
573 && ! (GET_CODE (x
) == PLUS
574 && (XEXP (x
, 0) == virtual_stack_vars_rtx
575 || XEXP (x
, 0) == virtual_incoming_args_rtx
)))
577 if (general_operand (x
, Pmode
))
578 x
= force_reg (Pmode
, x
);
580 x
= force_operand (x
, NULL_RTX
);
586 /* If we didn't change the address, we are done. Otherwise, mark
587 a reg as a pointer if we have REG or REG + CONST_INT. */
590 else if (GET_CODE (x
) == REG
)
591 mark_reg_pointer (x
, BITS_PER_UNIT
);
592 else if (GET_CODE (x
) == PLUS
593 && GET_CODE (XEXP (x
, 0)) == REG
594 && GET_CODE (XEXP (x
, 1)) == CONST_INT
)
595 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
597 /* OLDX may have been the address on a temporary. Update the address
598 to indicate that X is now used. */
599 update_temp_slot_address (oldx
, x
);
604 /* Like `memory_address' but pretend `flag_force_addr' is 0. */
607 memory_address_noforce (mode
, x
)
608 enum machine_mode mode
;
611 int ambient_force_addr
= flag_force_addr
;
615 val
= memory_address (mode
, x
);
616 flag_force_addr
= ambient_force_addr
;
620 /* Convert a mem ref into one with a valid memory address.
621 Pass through anything else unchanged. */
627 if (GET_CODE (ref
) != MEM
)
629 if (memory_address_p (GET_MODE (ref
), XEXP (ref
, 0)))
631 /* Don't alter REF itself, since that is probably a stack slot. */
632 return change_address (ref
, GET_MODE (ref
), XEXP (ref
, 0));
635 /* Given REF, either a MEM or a REG, and T, either the type of X or
636 the expression corresponding to REF, set RTX_UNCHANGING_P if
640 maybe_set_unchanging (ref
, t
)
644 /* We can set RTX_UNCHANGING_P from TREE_READONLY for decls whose
645 initialization is only executed once, or whose initializer always
646 has the same value. Currently we simplify this to PARM_DECLs in the
647 first case, and decls with TREE_CONSTANT initializers in the second. */
648 if ((TREE_READONLY (t
) && DECL_P (t
)
649 && (TREE_CODE (t
) == PARM_DECL
650 || DECL_INITIAL (t
) == NULL_TREE
651 || TREE_CONSTANT (DECL_INITIAL (t
))))
652 || TREE_CODE_CLASS (TREE_CODE (t
)) == 'c')
653 RTX_UNCHANGING_P (ref
) = 1;
656 /* Given REF, a MEM, and T, either the type of X or the expression
657 corresponding to REF, set the memory attributes. OBJECTP is nonzero
658 if we are making a new object of this type. */
661 set_mem_attributes (ref
, t
, objectp
)
668 /* It can happen that type_for_mode was given a mode for which there
669 is no language-level type. In which case it returns NULL, which
674 type
= TYPE_P (t
) ? t
: TREE_TYPE (t
);
676 /* Get the alias set from the expression or type (perhaps using a
677 front-end routine) and then copy bits from the type. */
679 /* It is incorrect to set RTX_UNCHANGING_P from TREE_READONLY (type)
680 here, because, in C and C++, the fact that a location is accessed
681 through a const expression does not mean that the value there can
683 MEM_ALIAS_SET (ref
) = get_alias_set (t
);
684 MEM_VOLATILE_P (ref
) = TYPE_VOLATILE (type
);
685 MEM_IN_STRUCT_P (ref
) = AGGREGATE_TYPE_P (type
);
687 /* If we are making an object of this type, we know that it is a scalar if
688 the type is not an aggregate. */
689 if (objectp
&& ! AGGREGATE_TYPE_P (type
))
690 MEM_SCALAR_P (ref
) = 1;
692 /* If T is a type, this is all we can do. Otherwise, we may be able
693 to deduce some more information about the expression. */
697 maybe_set_unchanging (ref
, t
);
698 if (TREE_THIS_VOLATILE (t
))
699 MEM_VOLATILE_P (ref
) = 1;
701 /* Now see if we can say more about whether it's an aggregate or
702 scalar. If we already know it's an aggregate, don't bother. */
703 if (MEM_IN_STRUCT_P (ref
))
706 /* Now remove any NOPs: they don't change what the underlying object is.
707 Likewise for SAVE_EXPR. */
708 while (TREE_CODE (t
) == NOP_EXPR
|| TREE_CODE (t
) == CONVERT_EXPR
709 || TREE_CODE (t
) == NON_LVALUE_EXPR
|| TREE_CODE (t
) == SAVE_EXPR
)
710 t
= TREE_OPERAND (t
, 0);
712 /* Since we already know the type isn't an aggregate, if this is a decl,
713 it must be a scalar. Or if it is a reference into an aggregate,
714 this is part of an aggregate. Otherwise we don't know. */
716 MEM_SCALAR_P (ref
) = 1;
717 else if (TREE_CODE (t
) == COMPONENT_REF
|| TREE_CODE (t
) == ARRAY_REF
718 || TREE_CODE (t
) == BIT_FIELD_REF
)
719 MEM_IN_STRUCT_P (ref
) = 1;
722 /* Return a modified copy of X with its memory address copied
723 into a temporary register to protect it from side effects.
724 If X is not a MEM, it is returned unchanged (and not copied).
725 Perhaps even if it is a MEM, if there is no need to change it. */
733 if (GET_CODE (x
) != MEM
)
737 if (rtx_unstable_p (addr
))
739 rtx temp
= force_reg (Pmode
, copy_all_regs (addr
));
740 rtx mem
= gen_rtx_MEM (GET_MODE (x
), temp
);
742 MEM_COPY_ATTRIBUTES (mem
, x
);
748 /* Copy the value or contents of X to a new temp reg and return that reg. */
754 register rtx temp
= gen_reg_rtx (GET_MODE (x
));
756 /* If not an operand, must be an address with PLUS and MULT so
757 do the computation. */
758 if (! general_operand (x
, VOIDmode
))
759 x
= force_operand (x
, temp
);
762 emit_move_insn (temp
, x
);
767 /* Like copy_to_reg but always give the new register mode Pmode
768 in case X is a constant. */
774 return copy_to_mode_reg (Pmode
, x
);
777 /* Like copy_to_reg but always give the new register mode MODE
778 in case X is a constant. */
781 copy_to_mode_reg (mode
, x
)
782 enum machine_mode mode
;
785 register rtx temp
= gen_reg_rtx (mode
);
787 /* If not an operand, must be an address with PLUS and MULT so
788 do the computation. */
789 if (! general_operand (x
, VOIDmode
))
790 x
= force_operand (x
, temp
);
792 if (GET_MODE (x
) != mode
&& GET_MODE (x
) != VOIDmode
)
795 emit_move_insn (temp
, x
);
799 /* Load X into a register if it is not already one.
800 Use mode MODE for the register.
801 X should be valid for mode MODE, but it may be a constant which
802 is valid for all integer modes; that's why caller must specify MODE.
804 The caller must not alter the value in the register we return,
805 since we mark it as a "constant" register. */
809 enum machine_mode mode
;
812 register rtx temp
, insn
, set
;
814 if (GET_CODE (x
) == REG
)
817 temp
= gen_reg_rtx (mode
);
819 if (! general_operand (x
, mode
))
820 x
= force_operand (x
, NULL_RTX
);
822 insn
= emit_move_insn (temp
, x
);
824 /* Let optimizers know that TEMP's value never changes
825 and that X can be substituted for it. Don't get confused
826 if INSN set something else (such as a SUBREG of TEMP). */
828 && (set
= single_set (insn
)) != 0
829 && SET_DEST (set
) == temp
)
831 rtx note
= find_reg_note (insn
, REG_EQUAL
, NULL_RTX
);
836 REG_NOTES (insn
) = gen_rtx_EXPR_LIST (REG_EQUAL
, x
, REG_NOTES (insn
));
841 /* If X is a memory ref, copy its contents to a new temp reg and return
842 that reg. Otherwise, return X. */
850 if (GET_CODE (x
) != MEM
|| GET_MODE (x
) == BLKmode
)
853 temp
= gen_reg_rtx (GET_MODE (x
));
854 emit_move_insn (temp
, x
);
858 /* Copy X to TARGET (if it's nonzero and a reg)
859 or to a new temp reg and return that reg.
860 MODE is the mode to use for X in case it is a constant. */
863 copy_to_suggested_reg (x
, target
, mode
)
865 enum machine_mode mode
;
869 if (target
&& GET_CODE (target
) == REG
)
872 temp
= gen_reg_rtx (mode
);
874 emit_move_insn (temp
, x
);
878 /* Return the mode to use to store a scalar of TYPE and MODE.
879 PUNSIGNEDP points to the signedness of the type and may be adjusted
880 to show what signedness to use on extension operations.
882 FOR_CALL is non-zero if this call is promoting args for a call. */
885 promote_mode (type
, mode
, punsignedp
, for_call
)
887 enum machine_mode mode
;
889 int for_call ATTRIBUTE_UNUSED
;
891 enum tree_code code
= TREE_CODE (type
);
892 int unsignedp
= *punsignedp
;
894 #ifdef PROMOTE_FOR_CALL_ONLY
902 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
903 case CHAR_TYPE
: case REAL_TYPE
: case OFFSET_TYPE
:
904 PROMOTE_MODE (mode
, unsignedp
, type
);
908 #ifdef POINTERS_EXTEND_UNSIGNED
912 unsignedp
= POINTERS_EXTEND_UNSIGNED
;
920 *punsignedp
= unsignedp
;
924 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
925 This pops when ADJUST is positive. ADJUST need not be constant. */
928 adjust_stack (adjust
)
932 adjust
= protect_from_queue (adjust
, 0);
934 if (adjust
== const0_rtx
)
937 /* We expect all variable sized adjustments to be multiple of
938 PREFERRED_STACK_BOUNDARY. */
939 if (GET_CODE (adjust
) == CONST_INT
)
940 stack_pointer_delta
-= INTVAL (adjust
);
942 temp
= expand_binop (Pmode
,
943 #ifdef STACK_GROWS_DOWNWARD
948 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
951 if (temp
!= stack_pointer_rtx
)
952 emit_move_insn (stack_pointer_rtx
, temp
);
955 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
956 This pushes when ADJUST is positive. ADJUST need not be constant. */
959 anti_adjust_stack (adjust
)
963 adjust
= protect_from_queue (adjust
, 0);
965 if (adjust
== const0_rtx
)
968 /* We expect all variable sized adjustments to be multiple of
969 PREFERRED_STACK_BOUNDARY. */
970 if (GET_CODE (adjust
) == CONST_INT
)
971 stack_pointer_delta
+= INTVAL (adjust
);
973 temp
= expand_binop (Pmode
,
974 #ifdef STACK_GROWS_DOWNWARD
979 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
982 if (temp
!= stack_pointer_rtx
)
983 emit_move_insn (stack_pointer_rtx
, temp
);
986 /* Round the size of a block to be pushed up to the boundary required
987 by this machine. SIZE is the desired size, which need not be constant. */
993 #ifdef PREFERRED_STACK_BOUNDARY
994 int align
= PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
;
997 if (GET_CODE (size
) == CONST_INT
)
999 int new = (INTVAL (size
) + align
- 1) / align
* align
;
1000 if (INTVAL (size
) != new)
1001 size
= GEN_INT (new);
1005 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1006 but we know it can't. So add ourselves and then do
1008 size
= expand_binop (Pmode
, add_optab
, size
, GEN_INT (align
- 1),
1009 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1010 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, GEN_INT (align
),
1012 size
= expand_mult (Pmode
, size
, GEN_INT (align
), NULL_RTX
, 1);
1014 #endif /* PREFERRED_STACK_BOUNDARY */
1018 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
1019 to a previously-created save area. If no save area has been allocated,
1020 this function will allocate one. If a save area is specified, it
1021 must be of the proper mode.
1023 The insns are emitted after insn AFTER, if nonzero, otherwise the insns
1024 are emitted at the current position. */
1027 emit_stack_save (save_level
, psave
, after
)
1028 enum save_level save_level
;
1033 /* The default is that we use a move insn and save in a Pmode object. */
1034 rtx (*fcn
) PARAMS ((rtx
, rtx
)) = gen_move_insn
;
1035 enum machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
1037 /* See if this machine has anything special to do for this kind of save. */
1040 #ifdef HAVE_save_stack_block
1042 if (HAVE_save_stack_block
)
1043 fcn
= gen_save_stack_block
;
1046 #ifdef HAVE_save_stack_function
1048 if (HAVE_save_stack_function
)
1049 fcn
= gen_save_stack_function
;
1052 #ifdef HAVE_save_stack_nonlocal
1054 if (HAVE_save_stack_nonlocal
)
1055 fcn
= gen_save_stack_nonlocal
;
1062 /* If there is no save area and we have to allocate one, do so. Otherwise
1063 verify the save area is the proper mode. */
1067 if (mode
!= VOIDmode
)
1069 if (save_level
== SAVE_NONLOCAL
)
1070 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1072 *psave
= sa
= gen_reg_rtx (mode
);
1077 if (mode
== VOIDmode
|| GET_MODE (sa
) != mode
)
1086 /* We must validize inside the sequence, to ensure that any instructions
1087 created by the validize call also get moved to the right place. */
1089 sa
= validize_mem (sa
);
1090 emit_insn (fcn (sa
, stack_pointer_rtx
));
1091 seq
= gen_sequence ();
1093 emit_insn_after (seq
, after
);
1098 sa
= validize_mem (sa
);
1099 emit_insn (fcn (sa
, stack_pointer_rtx
));
1103 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1104 area made by emit_stack_save. If it is zero, we have nothing to do.
1106 Put any emitted insns after insn AFTER, if nonzero, otherwise at
1107 current position. */
1110 emit_stack_restore (save_level
, sa
, after
)
1111 enum save_level save_level
;
1115 /* The default is that we use a move insn. */
1116 rtx (*fcn
) PARAMS ((rtx
, rtx
)) = gen_move_insn
;
1118 /* See if this machine has anything special to do for this kind of save. */
1121 #ifdef HAVE_restore_stack_block
1123 if (HAVE_restore_stack_block
)
1124 fcn
= gen_restore_stack_block
;
1127 #ifdef HAVE_restore_stack_function
1129 if (HAVE_restore_stack_function
)
1130 fcn
= gen_restore_stack_function
;
1133 #ifdef HAVE_restore_stack_nonlocal
1135 if (HAVE_restore_stack_nonlocal
)
1136 fcn
= gen_restore_stack_nonlocal
;
1144 sa
= validize_mem (sa
);
1151 emit_insn (fcn (stack_pointer_rtx
, sa
));
1152 seq
= gen_sequence ();
1154 emit_insn_after (seq
, after
);
1157 emit_insn (fcn (stack_pointer_rtx
, sa
));
1160 #ifdef SETJMP_VIA_SAVE_AREA
1161 /* Optimize RTL generated by allocate_dynamic_stack_space for targets
1162 where SETJMP_VIA_SAVE_AREA is true. The problem is that on these
1163 platforms, the dynamic stack space used can corrupt the original
1164 frame, thus causing a crash if a longjmp unwinds to it. */
1167 optimize_save_area_alloca (insns
)
1172 for (insn
= insns
; insn
; insn
= NEXT_INSN(insn
))
1176 if (GET_CODE (insn
) != INSN
)
1179 for (note
= REG_NOTES (insn
); note
; note
= XEXP (note
, 1))
1181 if (REG_NOTE_KIND (note
) != REG_SAVE_AREA
)
1184 if (!current_function_calls_setjmp
)
1186 rtx pat
= PATTERN (insn
);
1188 /* If we do not see the note in a pattern matching
1189 these precise characteristics, we did something
1190 entirely wrong in allocate_dynamic_stack_space.
1192 Note, one way this could happen is if SETJMP_VIA_SAVE_AREA
1193 was defined on a machine where stacks grow towards higher
1196 Right now only supported port with stack that grow upward
1197 is the HPPA and it does not define SETJMP_VIA_SAVE_AREA. */
1198 if (GET_CODE (pat
) != SET
1199 || SET_DEST (pat
) != stack_pointer_rtx
1200 || GET_CODE (SET_SRC (pat
)) != MINUS
1201 || XEXP (SET_SRC (pat
), 0) != stack_pointer_rtx
)
1204 /* This will now be transformed into a (set REG REG)
1205 so we can just blow away all the other notes. */
1206 XEXP (SET_SRC (pat
), 1) = XEXP (note
, 0);
1207 REG_NOTES (insn
) = NULL_RTX
;
1211 /* setjmp was called, we must remove the REG_SAVE_AREA
1212 note so that later passes do not get confused by its
1214 if (note
== REG_NOTES (insn
))
1216 REG_NOTES (insn
) = XEXP (note
, 1);
1222 for (srch
= REG_NOTES (insn
); srch
; srch
= XEXP (srch
, 1))
1223 if (XEXP (srch
, 1) == note
)
1226 if (srch
== NULL_RTX
)
1229 XEXP (srch
, 1) = XEXP (note
, 1);
1232 /* Once we've seen the note of interest, we need not look at
1233 the rest of them. */
1238 #endif /* SETJMP_VIA_SAVE_AREA */
1240 /* Return an rtx representing the address of an area of memory dynamically
1241 pushed on the stack. This region of memory is always aligned to
1242 a multiple of BIGGEST_ALIGNMENT.
1244 Any required stack pointer alignment is preserved.
1246 SIZE is an rtx representing the size of the area.
1247 TARGET is a place in which the address can be placed.
1249 KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */
1252 allocate_dynamic_stack_space (size
, target
, known_align
)
1257 #ifdef SETJMP_VIA_SAVE_AREA
1258 rtx setjmpless_size
= NULL_RTX
;
1261 /* If we're asking for zero bytes, it doesn't matter what we point
1262 to since we can't dereference it. But return a reasonable
1264 if (size
== const0_rtx
)
1265 return virtual_stack_dynamic_rtx
;
1267 /* Otherwise, show we're calling alloca or equivalent. */
1268 current_function_calls_alloca
= 1;
1270 /* Ensure the size is in the proper mode. */
1271 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1272 size
= convert_to_mode (Pmode
, size
, 1);
1274 /* We can't attempt to minimize alignment necessary, because we don't
1275 know the final value of preferred_stack_boundary yet while executing
1277 #ifdef PREFERRED_STACK_BOUNDARY
1278 cfun
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1281 /* We will need to ensure that the address we return is aligned to
1282 BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
1283 always know its final value at this point in the compilation (it
1284 might depend on the size of the outgoing parameter lists, for
1285 example), so we must align the value to be returned in that case.
1286 (Note that STACK_DYNAMIC_OFFSET will have a default non-zero value if
1287 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1288 We must also do an alignment operation on the returned value if
1289 the stack pointer alignment is less strict that BIGGEST_ALIGNMENT.
1291 If we have to align, we must leave space in SIZE for the hole
1292 that might result from the alignment operation. */
1294 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET) || ! defined (PREFERRED_STACK_BOUNDARY)
1295 #define MUST_ALIGN 1
1297 #define MUST_ALIGN (PREFERRED_STACK_BOUNDARY < BIGGEST_ALIGNMENT)
1302 if (GET_CODE (size
) == CONST_INT
)
1303 size
= GEN_INT (INTVAL (size
)
1304 + (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1));
1306 size
= expand_binop (Pmode
, add_optab
, size
,
1307 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1),
1308 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1311 #ifdef SETJMP_VIA_SAVE_AREA
1312 /* If setjmp restores regs from a save area in the stack frame,
1313 avoid clobbering the reg save area. Note that the offset of
1314 virtual_incoming_args_rtx includes the preallocated stack args space.
1315 It would be no problem to clobber that, but it's on the wrong side
1316 of the old save area. */
1319 = expand_binop (Pmode
, sub_optab
, virtual_stack_dynamic_rtx
,
1320 stack_pointer_rtx
, NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1322 if (!current_function_calls_setjmp
)
1324 int align
= PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
;
1326 /* See optimize_save_area_alloca to understand what is being
1329 #if !defined(PREFERRED_STACK_BOUNDARY) || !defined(MUST_ALIGN) || (PREFERRED_STACK_BOUNDARY != BIGGEST_ALIGNMENT)
1330 /* If anyone creates a target with these characteristics, let them
1331 know that our optimization cannot work correctly in such a case. */
1335 if (GET_CODE (size
) == CONST_INT
)
1337 int new = INTVAL (size
) / align
* align
;
1339 if (INTVAL (size
) != new)
1340 setjmpless_size
= GEN_INT (new);
1342 setjmpless_size
= size
;
1346 /* Since we know overflow is not possible, we avoid using
1347 CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */
1348 setjmpless_size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
,
1349 GEN_INT (align
), NULL_RTX
, 1);
1350 setjmpless_size
= expand_mult (Pmode
, setjmpless_size
,
1351 GEN_INT (align
), NULL_RTX
, 1);
1353 /* Our optimization works based upon being able to perform a simple
1354 transformation of this RTL into a (set REG REG) so make sure things
1355 did in fact end up in a REG. */
1356 if (!register_operand (setjmpless_size
, Pmode
))
1357 setjmpless_size
= force_reg (Pmode
, setjmpless_size
);
1360 size
= expand_binop (Pmode
, add_optab
, size
, dynamic_offset
,
1361 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1363 #endif /* SETJMP_VIA_SAVE_AREA */
1365 /* Round the size to a multiple of the required stack alignment.
1366 Since the stack if presumed to be rounded before this allocation,
1367 this will maintain the required alignment.
1369 If the stack grows downward, we could save an insn by subtracting
1370 SIZE from the stack pointer and then aligning the stack pointer.
1371 The problem with this is that the stack pointer may be unaligned
1372 between the execution of the subtraction and alignment insns and
1373 some machines do not allow this. Even on those that do, some
1374 signal handlers malfunction if a signal should occur between those
1375 insns. Since this is an extremely rare event, we have no reliable
1376 way of knowing which systems have this problem. So we avoid even
1377 momentarily mis-aligning the stack. */
1379 #ifdef PREFERRED_STACK_BOUNDARY
1380 /* If we added a variable amount to SIZE,
1381 we can no longer assume it is aligned. */
1382 #if !defined (SETJMP_VIA_SAVE_AREA)
1383 if (MUST_ALIGN
|| known_align
% PREFERRED_STACK_BOUNDARY
!= 0)
1385 size
= round_push (size
);
1388 do_pending_stack_adjust ();
1390 /* We ought to be called always on the toplevel and stack ought to be aligned
1392 #ifdef PREFERRED_STACK_BOUNDARY
1393 if (stack_pointer_delta
% (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
))
1397 /* If needed, check that we have the required amount of stack. Take into
1398 account what has already been checked. */
1399 if (flag_stack_check
&& ! STACK_CHECK_BUILTIN
)
1400 probe_stack_range (STACK_CHECK_MAX_FRAME_SIZE
+ STACK_CHECK_PROTECT
, size
);
1402 /* Don't use a TARGET that isn't a pseudo. */
1403 if (target
== 0 || GET_CODE (target
) != REG
1404 || REGNO (target
) < FIRST_PSEUDO_REGISTER
)
1405 target
= gen_reg_rtx (Pmode
);
1407 mark_reg_pointer (target
, known_align
);
1409 /* Perform the required allocation from the stack. Some systems do
1410 this differently than simply incrementing/decrementing from the
1411 stack pointer, such as acquiring the space by calling malloc(). */
1412 #ifdef HAVE_allocate_stack
1413 if (HAVE_allocate_stack
)
1415 enum machine_mode mode
= STACK_SIZE_MODE
;
1416 insn_operand_predicate_fn pred
;
1418 pred
= insn_data
[(int) CODE_FOR_allocate_stack
].operand
[0].predicate
;
1419 if (pred
&& ! ((*pred
) (target
, Pmode
)))
1420 #ifdef POINTERS_EXTEND_UNSIGNED
1421 target
= convert_memory_address (Pmode
, target
);
1423 target
= copy_to_mode_reg (Pmode
, target
);
1426 if (mode
== VOIDmode
)
1429 size
= convert_modes (mode
, ptr_mode
, size
, 1);
1430 pred
= insn_data
[(int) CODE_FOR_allocate_stack
].operand
[1].predicate
;
1431 if (pred
&& ! ((*pred
) (size
, mode
)))
1432 size
= copy_to_mode_reg (mode
, size
);
1434 emit_insn (gen_allocate_stack (target
, size
));
1439 #ifndef STACK_GROWS_DOWNWARD
1440 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1442 size
= convert_modes (Pmode
, ptr_mode
, size
, 1);
1444 /* Check stack bounds if necessary. */
1445 if (current_function_limit_stack
)
1448 rtx space_available
= gen_label_rtx ();
1449 #ifdef STACK_GROWS_DOWNWARD
1450 available
= expand_binop (Pmode
, sub_optab
,
1451 stack_pointer_rtx
, stack_limit_rtx
,
1452 NULL_RTX
, 1, OPTAB_WIDEN
);
1454 available
= expand_binop (Pmode
, sub_optab
,
1455 stack_limit_rtx
, stack_pointer_rtx
,
1456 NULL_RTX
, 1, OPTAB_WIDEN
);
1458 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1459 0, space_available
);
1462 emit_insn (gen_trap ());
1465 error ("stack limits not supported on this target");
1467 emit_label (space_available
);
1470 anti_adjust_stack (size
);
1471 #ifdef SETJMP_VIA_SAVE_AREA
1472 if (setjmpless_size
!= NULL_RTX
)
1474 rtx note_target
= get_last_insn ();
1476 REG_NOTES (note_target
)
1477 = gen_rtx_EXPR_LIST (REG_SAVE_AREA
, setjmpless_size
,
1478 REG_NOTES (note_target
));
1480 #endif /* SETJMP_VIA_SAVE_AREA */
1481 #ifdef STACK_GROWS_DOWNWARD
1482 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1488 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1489 but we know it can't. So add ourselves and then do
1491 target
= expand_binop (Pmode
, add_optab
, target
,
1492 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
- 1),
1493 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1494 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1495 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
),
1497 target
= expand_mult (Pmode
, target
,
1498 GEN_INT (BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
),
1502 /* Some systems require a particular insn to refer to the stack
1503 to make the pages exist. */
1506 emit_insn (gen_probe ());
1509 /* Record the new stack level for nonlocal gotos. */
1510 if (nonlocal_goto_handler_slots
!= 0)
1511 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
, NULL_RTX
);
1516 /* A front end may want to override GCC's stack checking by providing a
1517 run-time routine to call to check the stack, so provide a mechanism for
1518 calling that routine. */
1520 static rtx stack_check_libfunc
;
1523 set_stack_check_libfunc (libfunc
)
1526 stack_check_libfunc
= libfunc
;
1529 /* Emit one stack probe at ADDRESS, an address within the stack. */
1532 emit_stack_probe (address
)
1535 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1537 MEM_VOLATILE_P (memref
) = 1;
1539 if (STACK_CHECK_PROBE_LOAD
)
1540 emit_move_insn (gen_reg_rtx (word_mode
), memref
);
1542 emit_move_insn (memref
, const0_rtx
);
1545 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1546 FIRST is a constant and size is a Pmode RTX. These are offsets from the
1547 current stack pointer. STACK_GROWS_DOWNWARD says whether to add or
1548 subtract from the stack. If SIZE is constant, this is done
1549 with a fixed number of probes. Otherwise, we must make a loop. */
1551 #ifdef STACK_GROWS_DOWNWARD
1552 #define STACK_GROW_OP MINUS
1554 #define STACK_GROW_OP PLUS
1558 probe_stack_range (first
, size
)
1559 HOST_WIDE_INT first
;
1562 /* First see if the front end has set up a function for us to call to
1564 if (stack_check_libfunc
!= 0)
1565 emit_library_call (stack_check_libfunc
, 0, VOIDmode
, 1,
1566 memory_address (QImode
,
1567 gen_rtx (STACK_GROW_OP
, Pmode
,
1569 plus_constant (size
, first
))),
1572 /* Next see if we have an insn to check the stack. Use it if so. */
1573 #ifdef HAVE_check_stack
1574 else if (HAVE_check_stack
)
1576 insn_operand_predicate_fn pred
;
1578 = force_operand (gen_rtx_STACK_GROW_OP (Pmode
,
1580 plus_constant (size
, first
)),
1583 pred
= insn_data
[(int) CODE_FOR_check_stack
].operand
[0].predicate
;
1584 if (pred
&& ! ((*pred
) (last_addr
, Pmode
)))
1585 last_addr
= copy_to_mode_reg (Pmode
, last_addr
);
1587 emit_insn (gen_check_stack (last_addr
));
1591 /* If we have to generate explicit probes, see if we have a constant
1592 small number of them to generate. If so, that's the easy case. */
1593 else if (GET_CODE (size
) == CONST_INT
1594 && INTVAL (size
) < 10 * STACK_CHECK_PROBE_INTERVAL
)
1596 HOST_WIDE_INT offset
;
1598 /* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL
1599 for values of N from 1 until it exceeds LAST. If only one
1600 probe is needed, this will not generate any code. Then probe
1602 for (offset
= first
+ STACK_CHECK_PROBE_INTERVAL
;
1603 offset
< INTVAL (size
);
1604 offset
= offset
+ STACK_CHECK_PROBE_INTERVAL
)
1605 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1609 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1611 plus_constant (size
, first
)));
1614 /* In the variable case, do the same as above, but in a loop. We emit loop
1615 notes so that loop optimization can be done. */
1619 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1621 GEN_INT (first
+ STACK_CHECK_PROBE_INTERVAL
)),
1624 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1626 plus_constant (size
, first
)),
1628 rtx incr
= GEN_INT (STACK_CHECK_PROBE_INTERVAL
);
1629 rtx loop_lab
= gen_label_rtx ();
1630 rtx test_lab
= gen_label_rtx ();
1631 rtx end_lab
= gen_label_rtx ();
1634 if (GET_CODE (test_addr
) != REG
1635 || REGNO (test_addr
) < FIRST_PSEUDO_REGISTER
)
1636 test_addr
= force_reg (Pmode
, test_addr
);
1638 emit_note (NULL_PTR
, NOTE_INSN_LOOP_BEG
);
1639 emit_jump (test_lab
);
1641 emit_label (loop_lab
);
1642 emit_stack_probe (test_addr
);
1644 emit_note (NULL_PTR
, NOTE_INSN_LOOP_CONT
);
1646 #ifdef STACK_GROWS_DOWNWARD
1647 #define CMP_OPCODE GTU
1648 temp
= expand_binop (Pmode
, sub_optab
, test_addr
, incr
, test_addr
,
1651 #define CMP_OPCODE LTU
1652 temp
= expand_binop (Pmode
, add_optab
, test_addr
, incr
, test_addr
,
1656 if (temp
!= test_addr
)
1659 emit_label (test_lab
);
1660 emit_cmp_and_jump_insns (test_addr
, last_addr
, CMP_OPCODE
,
1661 NULL_RTX
, Pmode
, 1, 0, loop_lab
);
1662 emit_jump (end_lab
);
1663 emit_note (NULL_PTR
, NOTE_INSN_LOOP_END
);
1664 emit_label (end_lab
);
1666 emit_stack_probe (last_addr
);
1670 /* Return an rtx representing the register or memory location
1671 in which a scalar value of data type VALTYPE
1672 was returned by a function call to function FUNC.
1673 FUNC is a FUNCTION_DECL node if the precise function is known,
1675 OUTGOING is 1 if on a machine with register windows this function
1676 should return the register in which the function will put its result
1680 hard_function_value (valtype
, func
, outgoing
)
1682 tree func ATTRIBUTE_UNUSED
;
1683 int outgoing ATTRIBUTE_UNUSED
;
1687 #ifdef FUNCTION_OUTGOING_VALUE
1689 val
= FUNCTION_OUTGOING_VALUE (valtype
, func
);
1692 val
= FUNCTION_VALUE (valtype
, func
);
1694 if (GET_CODE (val
) == REG
1695 && GET_MODE (val
) == BLKmode
)
1697 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1698 enum machine_mode tmpmode
;
1700 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1701 tmpmode
!= VOIDmode
;
1702 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1704 /* Have we found a large enough mode? */
1705 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1709 /* No suitable mode found. */
1710 if (tmpmode
== VOIDmode
)
1713 PUT_MODE (val
, tmpmode
);
1718 /* Return an rtx representing the register or memory location
1719 in which a scalar value of mode MODE was returned by a library call. */
1722 hard_libcall_value (mode
)
1723 enum machine_mode mode
;
1725 return LIBCALL_VALUE (mode
);
1728 /* Look up the tree code for a given rtx code
1729 to provide the arithmetic operation for REAL_ARITHMETIC.
1730 The function returns an int because the caller may not know
1731 what `enum tree_code' means. */
1734 rtx_to_tree_code (code
)
1737 enum tree_code tcode
;
1760 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1763 return ((int) tcode
);