1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987, 1991, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
25 #include "coretypes.h"
27 #include "diagnostic-core.h"
37 #include "hard-reg-set.h"
38 #include "insn-config.h"
41 #include "langhooks.h"
43 #include "common/common-target.h"
46 static rtx
break_out_memory_refs (rtx
);
49 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
52 trunc_int_for_mode (HOST_WIDE_INT c
, enum machine_mode mode
)
54 int width
= GET_MODE_PRECISION (mode
);
56 /* You want to truncate to a _what_? */
57 gcc_assert (SCALAR_INT_MODE_P (mode
));
59 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
61 return c
& 1 ? STORE_FLAG_VALUE
: 0;
63 /* Sign-extend for the requested mode. */
65 if (width
< HOST_BITS_PER_WIDE_INT
)
67 HOST_WIDE_INT sign
= 1;
77 /* Return an rtx for the sum of X and the integer C. */
80 plus_constant (rtx x
, HOST_WIDE_INT c
)
84 enum machine_mode mode
;
100 return GEN_INT (INTVAL (x
) + c
);
104 unsigned HOST_WIDE_INT l1
= CONST_DOUBLE_LOW (x
);
105 HOST_WIDE_INT h1
= CONST_DOUBLE_HIGH (x
);
106 unsigned HOST_WIDE_INT l2
= c
;
107 HOST_WIDE_INT h2
= c
< 0 ? ~0 : 0;
108 unsigned HOST_WIDE_INT lv
;
111 add_double (l1
, h1
, l2
, h2
, &lv
, &hv
);
113 return immed_double_const (lv
, hv
, VOIDmode
);
117 /* If this is a reference to the constant pool, try replacing it with
118 a reference to a new constant. If the resulting address isn't
119 valid, don't return it because we have no way to validize it. */
120 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
121 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
124 = force_const_mem (GET_MODE (x
),
125 plus_constant (get_pool_constant (XEXP (x
, 0)),
127 if (memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
133 /* If adding to something entirely constant, set a flag
134 so that we can add a CONST around the result. */
145 /* The interesting case is adding the integer to a sum.
146 Look for constant term in the sum and combine
147 with C. For an integer constant term, we make a combined
148 integer. For a constant term that is not an explicit integer,
149 we cannot really combine, but group them together anyway.
151 Restart or use a recursive call in case the remaining operand is
152 something that we handle specially, such as a SYMBOL_REF.
154 We may not immediately return from the recursive call here, lest
155 all_constant gets lost. */
157 if (CONST_INT_P (XEXP (x
, 1)))
159 c
+= INTVAL (XEXP (x
, 1));
161 if (GET_MODE (x
) != VOIDmode
)
162 c
= trunc_int_for_mode (c
, GET_MODE (x
));
167 else if (CONSTANT_P (XEXP (x
, 1)))
169 x
= gen_rtx_PLUS (mode
, XEXP (x
, 0), plus_constant (XEXP (x
, 1), c
));
172 else if (find_constant_term_loc (&y
))
174 /* We need to be careful since X may be shared and we can't
175 modify it in place. */
176 rtx copy
= copy_rtx (x
);
177 rtx
*const_loc
= find_constant_term_loc (©
);
179 *const_loc
= plus_constant (*const_loc
, c
);
190 x
= gen_rtx_PLUS (mode
, x
, GEN_INT (c
));
192 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
194 else if (all_constant
)
195 return gen_rtx_CONST (mode
, x
);
200 /* If X is a sum, return a new sum like X but lacking any constant terms.
201 Add all the removed constant terms into *CONSTPTR.
202 X itself is not altered. The result != X if and only if
203 it is not isomorphic to X. */
206 eliminate_constant_term (rtx x
, rtx
*constptr
)
211 if (GET_CODE (x
) != PLUS
)
214 /* First handle constants appearing at this level explicitly. */
215 if (CONST_INT_P (XEXP (x
, 1))
216 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
218 && CONST_INT_P (tem
))
221 return eliminate_constant_term (XEXP (x
, 0), constptr
);
225 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
226 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
227 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
228 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
230 && CONST_INT_P (tem
))
233 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
239 /* Return an rtx for the size in bytes of the value of EXP. */
246 if (TREE_CODE (exp
) == WITH_SIZE_EXPR
)
247 size
= TREE_OPERAND (exp
, 1);
250 size
= tree_expr_size (exp
);
252 gcc_assert (size
== SUBSTITUTE_PLACEHOLDER_IN_EXPR (size
, exp
));
255 return expand_expr (size
, NULL_RTX
, TYPE_MODE (sizetype
), EXPAND_NORMAL
);
258 /* Return a wide integer for the size in bytes of the value of EXP, or -1
259 if the size can vary or is larger than an integer. */
262 int_expr_size (tree exp
)
266 if (TREE_CODE (exp
) == WITH_SIZE_EXPR
)
267 size
= TREE_OPERAND (exp
, 1);
270 size
= tree_expr_size (exp
);
274 if (size
== 0 || !host_integerp (size
, 0))
277 return tree_low_cst (size
, 0);
280 /* Return a copy of X in which all memory references
281 and all constants that involve symbol refs
282 have been replaced with new temporary registers.
283 Also emit code to load the memory locations and constants
284 into those registers.
286 If X contains no such constants or memory references,
287 X itself (not a copy) is returned.
289 If a constant is found in the address that is not a legitimate constant
290 in an insn, it is left alone in the hope that it might be valid in the
293 X may contain no arithmetic except addition, subtraction and multiplication.
294 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
297 break_out_memory_refs (rtx x
)
300 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
301 && GET_MODE (x
) != VOIDmode
))
302 x
= force_reg (GET_MODE (x
), x
);
303 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
304 || GET_CODE (x
) == MULT
)
306 rtx op0
= break_out_memory_refs (XEXP (x
, 0));
307 rtx op1
= break_out_memory_refs (XEXP (x
, 1));
309 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
310 x
= simplify_gen_binary (GET_CODE (x
), GET_MODE (x
), op0
, op1
);
316 /* Given X, a memory address in address space AS' pointer mode, convert it to
317 an address in the address space's address mode, or vice versa (TO_MODE says
318 which way). We take advantage of the fact that pointers are not allowed to
319 overflow by commuting arithmetic operations over conversions so that address
320 arithmetic insns can be used. */
323 convert_memory_address_addr_space (enum machine_mode to_mode ATTRIBUTE_UNUSED
,
324 rtx x
, addr_space_t as ATTRIBUTE_UNUSED
)
326 #ifndef POINTERS_EXTEND_UNSIGNED
327 gcc_assert (GET_MODE (x
) == to_mode
|| GET_MODE (x
) == VOIDmode
);
329 #else /* defined(POINTERS_EXTEND_UNSIGNED) */
330 enum machine_mode pointer_mode
, address_mode
, from_mode
;
334 /* If X already has the right mode, just return it. */
335 if (GET_MODE (x
) == to_mode
)
338 pointer_mode
= targetm
.addr_space
.pointer_mode (as
);
339 address_mode
= targetm
.addr_space
.address_mode (as
);
340 from_mode
= to_mode
== pointer_mode
? address_mode
: pointer_mode
;
342 /* Here we handle some special cases. If none of them apply, fall through
343 to the default case. */
344 switch (GET_CODE (x
))
348 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
))
350 else if (POINTERS_EXTEND_UNSIGNED
< 0)
352 else if (POINTERS_EXTEND_UNSIGNED
> 0)
356 temp
= simplify_unary_operation (code
, to_mode
, x
, from_mode
);
362 if ((SUBREG_PROMOTED_VAR_P (x
) || REG_POINTER (SUBREG_REG (x
)))
363 && GET_MODE (SUBREG_REG (x
)) == to_mode
)
364 return SUBREG_REG (x
);
368 temp
= gen_rtx_LABEL_REF (to_mode
, XEXP (x
, 0));
369 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
374 temp
= shallow_copy_rtx (x
);
375 PUT_MODE (temp
, to_mode
);
380 return gen_rtx_CONST (to_mode
,
381 convert_memory_address_addr_space
382 (to_mode
, XEXP (x
, 0), as
));
387 /* FIXME: For addition, we used to permute the conversion and
388 addition operation only if one operand is a constant and
389 converting the constant does not change it or if one operand
390 is a constant and we are using a ptr_extend instruction
391 (POINTERS_EXTEND_UNSIGNED < 0) even if the resulting address
392 may overflow/underflow. We relax the condition to include
393 zero-extend (POINTERS_EXTEND_UNSIGNED > 0) since the other
394 parts of the compiler depend on it. See PR 49721.
396 We can always safely permute them if we are making the address
398 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
399 || (GET_CODE (x
) == PLUS
400 && CONST_INT_P (XEXP (x
, 1))
401 && (POINTERS_EXTEND_UNSIGNED
!= 0
402 || XEXP (x
, 1) == convert_memory_address_addr_space
403 (to_mode
, XEXP (x
, 1), as
))))
404 return gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
405 convert_memory_address_addr_space
406 (to_mode
, XEXP (x
, 0), as
),
414 return convert_modes (to_mode
, from_mode
,
415 x
, POINTERS_EXTEND_UNSIGNED
);
416 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
419 /* Return something equivalent to X but valid as a memory address for something
420 of mode MODE in the named address space AS. When X is not itself valid,
421 this works by copying X or subexpressions of it into registers. */
424 memory_address_addr_space (enum machine_mode mode
, rtx x
, addr_space_t as
)
427 enum machine_mode address_mode
= targetm
.addr_space
.address_mode (as
);
429 x
= convert_memory_address_addr_space (address_mode
, x
, as
);
431 /* By passing constant addresses through registers
432 we get a chance to cse them. */
433 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
434 x
= force_reg (address_mode
, x
);
436 /* We get better cse by rejecting indirect addressing at this stage.
437 Let the combiner create indirect addresses where appropriate.
438 For now, generate the code so that the subexpressions useful to share
439 are visible. But not if cse won't be done! */
442 if (! cse_not_expected
&& !REG_P (x
))
443 x
= break_out_memory_refs (x
);
445 /* At this point, any valid address is accepted. */
446 if (memory_address_addr_space_p (mode
, x
, as
))
449 /* If it was valid before but breaking out memory refs invalidated it,
450 use it the old way. */
451 if (memory_address_addr_space_p (mode
, oldx
, as
))
457 /* Perform machine-dependent transformations on X
458 in certain cases. This is not necessary since the code
459 below can handle all possible cases, but machine-dependent
460 transformations can make better code. */
463 x
= targetm
.addr_space
.legitimize_address (x
, oldx
, mode
, as
);
464 if (orig_x
!= x
&& memory_address_addr_space_p (mode
, x
, as
))
468 /* PLUS and MULT can appear in special ways
469 as the result of attempts to make an address usable for indexing.
470 Usually they are dealt with by calling force_operand, below.
471 But a sum containing constant terms is special
472 if removing them makes the sum a valid address:
473 then we generate that address in a register
474 and index off of it. We do this because it often makes
475 shorter code, and because the addresses thus generated
476 in registers often become common subexpressions. */
477 if (GET_CODE (x
) == PLUS
)
479 rtx constant_term
= const0_rtx
;
480 rtx y
= eliminate_constant_term (x
, &constant_term
);
481 if (constant_term
== const0_rtx
482 || ! memory_address_addr_space_p (mode
, y
, as
))
483 x
= force_operand (x
, NULL_RTX
);
486 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
487 if (! memory_address_addr_space_p (mode
, y
, as
))
488 x
= force_operand (x
, NULL_RTX
);
494 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
495 x
= force_operand (x
, NULL_RTX
);
497 /* If we have a register that's an invalid address,
498 it must be a hard reg of the wrong class. Copy it to a pseudo. */
502 /* Last resort: copy the value to a register, since
503 the register is a valid address. */
505 x
= force_reg (address_mode
, x
);
510 gcc_assert (memory_address_addr_space_p (mode
, x
, as
));
511 /* If we didn't change the address, we are done. Otherwise, mark
512 a reg as a pointer if we have REG or REG + CONST_INT. */
516 mark_reg_pointer (x
, BITS_PER_UNIT
);
517 else if (GET_CODE (x
) == PLUS
518 && REG_P (XEXP (x
, 0))
519 && CONST_INT_P (XEXP (x
, 1)))
520 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
522 /* OLDX may have been the address on a temporary. Update the address
523 to indicate that X is now used. */
524 update_temp_slot_address (oldx
, x
);
529 /* Convert a mem ref into one with a valid memory address.
530 Pass through anything else unchanged. */
533 validize_mem (rtx ref
)
537 ref
= use_anchored_address (ref
);
538 if (memory_address_addr_space_p (GET_MODE (ref
), XEXP (ref
, 0),
539 MEM_ADDR_SPACE (ref
)))
542 /* Don't alter REF itself, since that is probably a stack slot. */
543 return replace_equiv_address (ref
, XEXP (ref
, 0));
546 /* If X is a memory reference to a member of an object block, try rewriting
547 it to use an anchor instead. Return the new memory reference on success
548 and the old one on failure. */
551 use_anchored_address (rtx x
)
554 HOST_WIDE_INT offset
;
556 if (!flag_section_anchors
)
562 /* Split the address into a base and offset. */
565 if (GET_CODE (base
) == CONST
566 && GET_CODE (XEXP (base
, 0)) == PLUS
567 && CONST_INT_P (XEXP (XEXP (base
, 0), 1)))
569 offset
+= INTVAL (XEXP (XEXP (base
, 0), 1));
570 base
= XEXP (XEXP (base
, 0), 0);
573 /* Check whether BASE is suitable for anchors. */
574 if (GET_CODE (base
) != SYMBOL_REF
575 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base
)
576 || SYMBOL_REF_ANCHOR_P (base
)
577 || SYMBOL_REF_BLOCK (base
) == NULL
578 || !targetm
.use_anchors_for_symbol_p (base
))
581 /* Decide where BASE is going to be. */
582 place_block_symbol (base
);
584 /* Get the anchor we need to use. */
585 offset
+= SYMBOL_REF_BLOCK_OFFSET (base
);
586 base
= get_section_anchor (SYMBOL_REF_BLOCK (base
), offset
,
587 SYMBOL_REF_TLS_MODEL (base
));
589 /* Work out the offset from the anchor. */
590 offset
-= SYMBOL_REF_BLOCK_OFFSET (base
);
592 /* If we're going to run a CSE pass, force the anchor into a register.
593 We will then be able to reuse registers for several accesses, if the
594 target costs say that that's worthwhile. */
595 if (!cse_not_expected
)
596 base
= force_reg (GET_MODE (base
), base
);
598 return replace_equiv_address (x
, plus_constant (base
, offset
));
601 /* Copy the value or contents of X to a new temp reg and return that reg. */
606 rtx temp
= gen_reg_rtx (GET_MODE (x
));
608 /* If not an operand, must be an address with PLUS and MULT so
609 do the computation. */
610 if (! general_operand (x
, VOIDmode
))
611 x
= force_operand (x
, temp
);
614 emit_move_insn (temp
, x
);
619 /* Like copy_to_reg but always give the new register mode Pmode
620 in case X is a constant. */
623 copy_addr_to_reg (rtx x
)
625 return copy_to_mode_reg (Pmode
, x
);
628 /* Like copy_to_reg but always give the new register mode MODE
629 in case X is a constant. */
632 copy_to_mode_reg (enum machine_mode mode
, rtx x
)
634 rtx temp
= gen_reg_rtx (mode
);
636 /* If not an operand, must be an address with PLUS and MULT so
637 do the computation. */
638 if (! general_operand (x
, VOIDmode
))
639 x
= force_operand (x
, temp
);
641 gcc_assert (GET_MODE (x
) == mode
|| GET_MODE (x
) == VOIDmode
);
643 emit_move_insn (temp
, x
);
647 /* Load X into a register if it is not already one.
648 Use mode MODE for the register.
649 X should be valid for mode MODE, but it may be a constant which
650 is valid for all integer modes; that's why caller must specify MODE.
652 The caller must not alter the value in the register we return,
653 since we mark it as a "constant" register. */
656 force_reg (enum machine_mode mode
, rtx x
)
663 if (general_operand (x
, mode
))
665 temp
= gen_reg_rtx (mode
);
666 insn
= emit_move_insn (temp
, x
);
670 temp
= force_operand (x
, NULL_RTX
);
672 insn
= get_last_insn ();
675 rtx temp2
= gen_reg_rtx (mode
);
676 insn
= emit_move_insn (temp2
, temp
);
681 /* Let optimizers know that TEMP's value never changes
682 and that X can be substituted for it. Don't get confused
683 if INSN set something else (such as a SUBREG of TEMP). */
685 && (set
= single_set (insn
)) != 0
686 && SET_DEST (set
) == temp
687 && ! rtx_equal_p (x
, SET_SRC (set
)))
688 set_unique_reg_note (insn
, REG_EQUAL
, x
);
690 /* Let optimizers know that TEMP is a pointer, and if so, the
691 known alignment of that pointer. */
694 if (GET_CODE (x
) == SYMBOL_REF
)
696 align
= BITS_PER_UNIT
;
697 if (SYMBOL_REF_DECL (x
) && DECL_P (SYMBOL_REF_DECL (x
)))
698 align
= DECL_ALIGN (SYMBOL_REF_DECL (x
));
700 else if (GET_CODE (x
) == LABEL_REF
)
701 align
= BITS_PER_UNIT
;
702 else if (GET_CODE (x
) == CONST
703 && GET_CODE (XEXP (x
, 0)) == PLUS
704 && GET_CODE (XEXP (XEXP (x
, 0), 0)) == SYMBOL_REF
705 && CONST_INT_P (XEXP (XEXP (x
, 0), 1)))
707 rtx s
= XEXP (XEXP (x
, 0), 0);
708 rtx c
= XEXP (XEXP (x
, 0), 1);
712 if (SYMBOL_REF_DECL (s
) && DECL_P (SYMBOL_REF_DECL (s
)))
713 sa
= DECL_ALIGN (SYMBOL_REF_DECL (s
));
719 ca
= ctz_hwi (INTVAL (c
)) * BITS_PER_UNIT
;
720 align
= MIN (sa
, ca
);
724 if (align
|| (MEM_P (x
) && MEM_POINTER (x
)))
725 mark_reg_pointer (temp
, align
);
731 /* If X is a memory ref, copy its contents to a new temp reg and return
732 that reg. Otherwise, return X. */
735 force_not_mem (rtx x
)
739 if (!MEM_P (x
) || GET_MODE (x
) == BLKmode
)
742 temp
= gen_reg_rtx (GET_MODE (x
));
745 REG_POINTER (temp
) = 1;
747 emit_move_insn (temp
, x
);
751 /* Copy X to TARGET (if it's nonzero and a reg)
752 or to a new temp reg and return that reg.
753 MODE is the mode to use for X in case it is a constant. */
756 copy_to_suggested_reg (rtx x
, rtx target
, enum machine_mode mode
)
760 if (target
&& REG_P (target
))
763 temp
= gen_reg_rtx (mode
);
765 emit_move_insn (temp
, x
);
769 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
770 PUNSIGNEDP points to the signedness of the type and may be adjusted
771 to show what signedness to use on extension operations.
773 FOR_RETURN is nonzero if the caller is promoting the return value
774 of FNDECL, else it is for promoting args. */
777 promote_function_mode (const_tree type
, enum machine_mode mode
, int *punsignedp
,
778 const_tree funtype
, int for_return
)
780 /* Called without a type node for a libcall. */
781 if (type
== NULL_TREE
)
783 if (INTEGRAL_MODE_P (mode
))
784 return targetm
.calls
.promote_function_mode (NULL_TREE
, mode
,
791 switch (TREE_CODE (type
))
793 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
794 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
795 case POINTER_TYPE
: case REFERENCE_TYPE
:
796 return targetm
.calls
.promote_function_mode (type
, mode
, punsignedp
, funtype
,
803 /* Return the mode to use to store a scalar of TYPE and MODE.
804 PUNSIGNEDP points to the signedness of the type and may be adjusted
805 to show what signedness to use on extension operations. */
808 promote_mode (const_tree type ATTRIBUTE_UNUSED
, enum machine_mode mode
,
809 int *punsignedp ATTRIBUTE_UNUSED
)
816 /* For libcalls this is invoked without TYPE from the backends
817 TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
819 if (type
== NULL_TREE
)
822 /* FIXME: this is the same logic that was there until GCC 4.4, but we
823 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
824 is not defined. The affected targets are M32C, S390, SPARC. */
826 code
= TREE_CODE (type
);
827 unsignedp
= *punsignedp
;
831 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
832 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
833 PROMOTE_MODE (mode
, unsignedp
, type
);
834 *punsignedp
= unsignedp
;
838 #ifdef POINTERS_EXTEND_UNSIGNED
841 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
842 return targetm
.addr_space
.address_mode
843 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
856 /* Use one of promote_mode or promote_function_mode to find the promoted
857 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
858 of DECL after promotion. */
861 promote_decl_mode (const_tree decl
, int *punsignedp
)
863 tree type
= TREE_TYPE (decl
);
864 int unsignedp
= TYPE_UNSIGNED (type
);
865 enum machine_mode mode
= DECL_MODE (decl
);
866 enum machine_mode pmode
;
868 if (TREE_CODE (decl
) == RESULT_DECL
869 || TREE_CODE (decl
) == PARM_DECL
)
870 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
871 TREE_TYPE (current_function_decl
), 2);
873 pmode
= promote_mode (type
, mode
, &unsignedp
);
876 *punsignedp
= unsignedp
;
881 /* Controls the behaviour of {anti_,}adjust_stack. */
882 static bool suppress_reg_args_size
;
884 /* A helper for adjust_stack and anti_adjust_stack. */
887 adjust_stack_1 (rtx adjust
, bool anti_p
)
891 #ifndef STACK_GROWS_DOWNWARD
892 /* Hereafter anti_p means subtract_p. */
896 temp
= expand_binop (Pmode
,
897 anti_p
? sub_optab
: add_optab
,
898 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
901 if (temp
!= stack_pointer_rtx
)
902 insn
= emit_move_insn (stack_pointer_rtx
, temp
);
905 insn
= get_last_insn ();
906 temp
= single_set (insn
);
907 gcc_assert (temp
!= NULL
&& SET_DEST (temp
) == stack_pointer_rtx
);
910 if (!suppress_reg_args_size
)
911 add_reg_note (insn
, REG_ARGS_SIZE
, GEN_INT (stack_pointer_delta
));
914 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
915 This pops when ADJUST is positive. ADJUST need not be constant. */
918 adjust_stack (rtx adjust
)
920 if (adjust
== const0_rtx
)
923 /* We expect all variable sized adjustments to be multiple of
924 PREFERRED_STACK_BOUNDARY. */
925 if (CONST_INT_P (adjust
))
926 stack_pointer_delta
-= INTVAL (adjust
);
928 adjust_stack_1 (adjust
, false);
931 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
932 This pushes when ADJUST is positive. ADJUST need not be constant. */
935 anti_adjust_stack (rtx adjust
)
937 if (adjust
== const0_rtx
)
940 /* We expect all variable sized adjustments to be multiple of
941 PREFERRED_STACK_BOUNDARY. */
942 if (CONST_INT_P (adjust
))
943 stack_pointer_delta
+= INTVAL (adjust
);
945 adjust_stack_1 (adjust
, true);
948 /* Round the size of a block to be pushed up to the boundary required
949 by this machine. SIZE is the desired size, which need not be constant. */
952 round_push (rtx size
)
954 rtx align_rtx
, alignm1_rtx
;
956 if (!SUPPORTS_STACK_ALIGNMENT
957 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
959 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
964 if (CONST_INT_P (size
))
966 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
968 if (INTVAL (size
) != new_size
)
969 size
= GEN_INT (new_size
);
973 align_rtx
= GEN_INT (align
);
974 alignm1_rtx
= GEN_INT (align
- 1);
978 /* If crtl->preferred_stack_boundary might still grow, use
979 virtual_preferred_stack_boundary_rtx instead. This will be
980 substituted by the right value in vregs pass and optimized
982 align_rtx
= virtual_preferred_stack_boundary_rtx
;
983 alignm1_rtx
= force_operand (plus_constant (align_rtx
, -1), NULL_RTX
);
986 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
987 but we know it can't. So add ourselves and then do
989 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
990 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
991 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
993 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
998 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
999 to a previously-created save area. If no save area has been allocated,
1000 this function will allocate one. If a save area is specified, it
1001 must be of the proper mode. */
1004 emit_stack_save (enum save_level save_level
, rtx
*psave
)
1007 /* The default is that we use a move insn and save in a Pmode object. */
1008 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
1009 enum machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
1011 /* See if this machine has anything special to do for this kind of save. */
1014 #ifdef HAVE_save_stack_block
1016 if (HAVE_save_stack_block
)
1017 fcn
= gen_save_stack_block
;
1020 #ifdef HAVE_save_stack_function
1022 if (HAVE_save_stack_function
)
1023 fcn
= gen_save_stack_function
;
1026 #ifdef HAVE_save_stack_nonlocal
1028 if (HAVE_save_stack_nonlocal
)
1029 fcn
= gen_save_stack_nonlocal
;
1036 /* If there is no save area and we have to allocate one, do so. Otherwise
1037 verify the save area is the proper mode. */
1041 if (mode
!= VOIDmode
)
1043 if (save_level
== SAVE_NONLOCAL
)
1044 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1046 *psave
= sa
= gen_reg_rtx (mode
);
1050 do_pending_stack_adjust ();
1052 sa
= validize_mem (sa
);
1053 emit_insn (fcn (sa
, stack_pointer_rtx
));
1056 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1057 area made by emit_stack_save. If it is zero, we have nothing to do. */
1060 emit_stack_restore (enum save_level save_level
, rtx sa
)
1062 /* The default is that we use a move insn. */
1063 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
1065 /* See if this machine has anything special to do for this kind of save. */
1068 #ifdef HAVE_restore_stack_block
1070 if (HAVE_restore_stack_block
)
1071 fcn
= gen_restore_stack_block
;
1074 #ifdef HAVE_restore_stack_function
1076 if (HAVE_restore_stack_function
)
1077 fcn
= gen_restore_stack_function
;
1080 #ifdef HAVE_restore_stack_nonlocal
1082 if (HAVE_restore_stack_nonlocal
)
1083 fcn
= gen_restore_stack_nonlocal
;
1092 sa
= validize_mem (sa
);
1093 /* These clobbers prevent the scheduler from moving
1094 references to variable arrays below the code
1095 that deletes (pops) the arrays. */
1096 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1097 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1100 discard_pending_stack_adjust ();
1102 emit_insn (fcn (stack_pointer_rtx
, sa
));
1105 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1106 function. This function should be called whenever we allocate or
1107 deallocate dynamic stack space. */
1110 update_nonlocal_goto_save_area (void)
1115 /* The nonlocal_goto_save_area object is an array of N pointers. The
1116 first one is used for the frame pointer save; the rest are sized by
1117 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1118 of the stack save area slots. */
1119 t_save
= build4 (ARRAY_REF
,
1120 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
1121 cfun
->nonlocal_goto_save_area
,
1122 integer_one_node
, NULL_TREE
, NULL_TREE
);
1123 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1125 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1128 /* Return an rtx representing the address of an area of memory dynamically
1129 pushed on the stack.
1131 Any required stack pointer alignment is preserved.
1133 SIZE is an rtx representing the size of the area.
1135 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1136 parameter may be zero. If so, a proper value will be extracted
1137 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1139 REQUIRED_ALIGN is the alignment (in bits) required for the region
1142 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1143 stack space allocated by the generated code cannot be added with itself
1144 in the course of the execution of the function. It is always safe to
1145 pass FALSE here and the following criterion is sufficient in order to
1146 pass TRUE: every path in the CFG that starts at the allocation point and
1147 loops to it executes the associated deallocation code. */
1150 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1151 unsigned required_align
, bool cannot_accumulate
)
1153 HOST_WIDE_INT stack_usage_size
= -1;
1154 rtx final_label
, final_target
, target
;
1155 unsigned extra_align
= 0;
1158 /* If we're asking for zero bytes, it doesn't matter what we point
1159 to since we can't dereference it. But return a reasonable
1161 if (size
== const0_rtx
)
1162 return virtual_stack_dynamic_rtx
;
1164 /* Otherwise, show we're calling alloca or equivalent. */
1165 cfun
->calls_alloca
= 1;
1167 /* If stack usage info is requested, look into the size we are passed.
1168 We need to do so this early to avoid the obfuscation that may be
1169 introduced later by the various alignment operations. */
1170 if (flag_stack_usage_info
)
1172 if (CONST_INT_P (size
))
1173 stack_usage_size
= INTVAL (size
);
1174 else if (REG_P (size
))
1176 /* Look into the last emitted insn and see if we can deduce
1177 something for the register. */
1178 rtx insn
, set
, note
;
1179 insn
= get_last_insn ();
1180 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1182 if (CONST_INT_P (SET_SRC (set
)))
1183 stack_usage_size
= INTVAL (SET_SRC (set
));
1184 else if ((note
= find_reg_equal_equiv_note (insn
))
1185 && CONST_INT_P (XEXP (note
, 0)))
1186 stack_usage_size
= INTVAL (XEXP (note
, 0));
1190 /* If the size is not constant, we can't say anything. */
1191 if (stack_usage_size
== -1)
1193 current_function_has_unbounded_dynamic_stack_size
= 1;
1194 stack_usage_size
= 0;
1198 /* Ensure the size is in the proper mode. */
1199 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1200 size
= convert_to_mode (Pmode
, size
, 1);
1202 /* Adjust SIZE_ALIGN, if needed. */
1203 if (CONST_INT_P (size
))
1205 unsigned HOST_WIDE_INT lsb
;
1207 lsb
= INTVAL (size
);
1210 /* Watch out for overflow truncating to "unsigned". */
1211 if (lsb
> UINT_MAX
/ BITS_PER_UNIT
)
1212 size_align
= 1u << (HOST_BITS_PER_INT
- 1);
1214 size_align
= (unsigned)lsb
* BITS_PER_UNIT
;
1216 else if (size_align
< BITS_PER_UNIT
)
1217 size_align
= BITS_PER_UNIT
;
1219 /* We can't attempt to minimize alignment necessary, because we don't
1220 know the final value of preferred_stack_boundary yet while executing
1222 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1223 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1225 /* We will need to ensure that the address we return is aligned to
1226 REQUIRED_ALIGN. If STACK_DYNAMIC_OFFSET is defined, we don't
1227 always know its final value at this point in the compilation (it
1228 might depend on the size of the outgoing parameter lists, for
1229 example), so we must align the value to be returned in that case.
1230 (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
1231 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1232 We must also do an alignment operation on the returned value if
1233 the stack pointer alignment is less strict than REQUIRED_ALIGN.
1235 If we have to align, we must leave space in SIZE for the hole
1236 that might result from the alignment operation. */
1238 must_align
= (crtl
->preferred_stack_boundary
< required_align
);
1241 if (required_align
> PREFERRED_STACK_BOUNDARY
)
1242 extra_align
= PREFERRED_STACK_BOUNDARY
;
1243 else if (required_align
> STACK_BOUNDARY
)
1244 extra_align
= STACK_BOUNDARY
;
1246 extra_align
= BITS_PER_UNIT
;
1249 /* ??? STACK_POINTER_OFFSET is always defined now. */
1250 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
1252 extra_align
= BITS_PER_UNIT
;
1257 unsigned extra
= (required_align
- extra_align
) / BITS_PER_UNIT
;
1259 size
= plus_constant (size
, extra
);
1260 size
= force_operand (size
, NULL_RTX
);
1262 if (flag_stack_usage_info
)
1263 stack_usage_size
+= extra
;
1265 if (extra
&& size_align
> extra_align
)
1266 size_align
= extra_align
;
1269 /* Round the size to a multiple of the required stack alignment.
1270 Since the stack if presumed to be rounded before this allocation,
1271 this will maintain the required alignment.
1273 If the stack grows downward, we could save an insn by subtracting
1274 SIZE from the stack pointer and then aligning the stack pointer.
1275 The problem with this is that the stack pointer may be unaligned
1276 between the execution of the subtraction and alignment insns and
1277 some machines do not allow this. Even on those that do, some
1278 signal handlers malfunction if a signal should occur between those
1279 insns. Since this is an extremely rare event, we have no reliable
1280 way of knowing which systems have this problem. So we avoid even
1281 momentarily mis-aligning the stack. */
1282 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1284 size
= round_push (size
);
1286 if (flag_stack_usage_info
)
1288 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1289 stack_usage_size
= (stack_usage_size
+ align
- 1) / align
* align
;
1293 target
= gen_reg_rtx (Pmode
);
1295 /* The size is supposed to be fully adjusted at this point so record it
1296 if stack usage info is requested. */
1297 if (flag_stack_usage_info
)
1299 current_function_dynamic_stack_size
+= stack_usage_size
;
1301 /* ??? This is gross but the only safe stance in the absence
1302 of stack usage oriented flow analysis. */
1303 if (!cannot_accumulate
)
1304 current_function_has_unbounded_dynamic_stack_size
= 1;
1307 final_label
= NULL_RTX
;
1308 final_target
= NULL_RTX
;
1310 /* If we are splitting the stack, we need to ask the backend whether
1311 there is enough room on the current stack. If there isn't, or if
1312 the backend doesn't know how to tell is, then we need to call a
1313 function to allocate memory in some other way. This memory will
1314 be released when we release the current stack segment. The
1315 effect is that stack allocation becomes less efficient, but at
1316 least it doesn't cause a stack overflow. */
1317 if (flag_split_stack
)
1319 rtx available_label
, ask
, space
, func
;
1321 available_label
= NULL_RTX
;
1323 #ifdef HAVE_split_stack_space_check
1324 if (HAVE_split_stack_space_check
)
1326 available_label
= gen_label_rtx ();
1328 /* This instruction will branch to AVAILABLE_LABEL if there
1329 are SIZE bytes available on the stack. */
1330 emit_insn (gen_split_stack_space_check (size
, available_label
));
1334 /* The __morestack_allocate_stack_space function will allocate
1335 memory using malloc. If the alignment of the memory returned
1336 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1337 make sure we allocate enough space. */
1338 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1342 ask
= expand_binop (Pmode
, add_optab
, size
,
1343 GEN_INT (required_align
/ BITS_PER_UNIT
- 1),
1344 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1348 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1350 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1353 if (available_label
== NULL_RTX
)
1356 final_target
= gen_reg_rtx (Pmode
);
1358 emit_move_insn (final_target
, space
);
1360 final_label
= gen_label_rtx ();
1361 emit_jump (final_label
);
1363 emit_label (available_label
);
1366 do_pending_stack_adjust ();
1368 /* We ought to be called always on the toplevel and stack ought to be aligned
1370 gcc_assert (!(stack_pointer_delta
1371 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1373 /* If needed, check that we have the required amount of stack. Take into
1374 account what has already been checked. */
1375 if (STACK_CHECK_MOVING_SP
)
1377 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1378 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1380 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1381 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1383 /* Don't let anti_adjust_stack emit notes. */
1384 suppress_reg_args_size
= true;
1386 /* Perform the required allocation from the stack. Some systems do
1387 this differently than simply incrementing/decrementing from the
1388 stack pointer, such as acquiring the space by calling malloc(). */
1389 #ifdef HAVE_allocate_stack
1390 if (HAVE_allocate_stack
)
1392 struct expand_operand ops
[2];
1393 /* We don't have to check against the predicate for operand 0 since
1394 TARGET is known to be a pseudo of the proper mode, which must
1395 be valid for the operand. */
1396 create_fixed_operand (&ops
[0], target
);
1397 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1398 expand_insn (CODE_FOR_allocate_stack
, 2, ops
);
1403 int saved_stack_pointer_delta
;
1405 #ifndef STACK_GROWS_DOWNWARD
1406 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1409 /* Check stack bounds if necessary. */
1410 if (crtl
->limit_stack
)
1413 rtx space_available
= gen_label_rtx ();
1414 #ifdef STACK_GROWS_DOWNWARD
1415 available
= expand_binop (Pmode
, sub_optab
,
1416 stack_pointer_rtx
, stack_limit_rtx
,
1417 NULL_RTX
, 1, OPTAB_WIDEN
);
1419 available
= expand_binop (Pmode
, sub_optab
,
1420 stack_limit_rtx
, stack_pointer_rtx
,
1421 NULL_RTX
, 1, OPTAB_WIDEN
);
1423 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1427 emit_insn (gen_trap ());
1430 error ("stack limits not supported on this target");
1432 emit_label (space_available
);
1435 saved_stack_pointer_delta
= stack_pointer_delta
;
1437 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1438 anti_adjust_stack_and_probe (size
, false);
1440 anti_adjust_stack (size
);
1442 /* Even if size is constant, don't modify stack_pointer_delta.
1443 The constant size alloca should preserve
1444 crtl->preferred_stack_boundary alignment. */
1445 stack_pointer_delta
= saved_stack_pointer_delta
;
1447 #ifdef STACK_GROWS_DOWNWARD
1448 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1452 suppress_reg_args_size
= false;
1454 /* Finish up the split stack handling. */
1455 if (final_label
!= NULL_RTX
)
1457 gcc_assert (flag_split_stack
);
1458 emit_move_insn (final_target
, target
);
1459 emit_label (final_label
);
1460 target
= final_target
;
1465 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1466 but we know it can't. So add ourselves and then do
1468 target
= expand_binop (Pmode
, add_optab
, target
,
1469 GEN_INT (required_align
/ BITS_PER_UNIT
- 1),
1470 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1471 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1472 GEN_INT (required_align
/ BITS_PER_UNIT
),
1474 target
= expand_mult (Pmode
, target
,
1475 GEN_INT (required_align
/ BITS_PER_UNIT
),
1479 /* Now that we've committed to a return value, mark its alignment. */
1480 mark_reg_pointer (target
, required_align
);
1482 /* Record the new stack level for nonlocal gotos. */
1483 if (cfun
->nonlocal_goto_save_area
!= 0)
1484 update_nonlocal_goto_save_area ();
1489 /* A front end may want to override GCC's stack checking by providing a
1490 run-time routine to call to check the stack, so provide a mechanism for
1491 calling that routine. */
1493 static GTY(()) rtx stack_check_libfunc
;
1496 set_stack_check_libfunc (const char *libfunc_name
)
1498 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1499 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1502 /* Emit one stack probe at ADDRESS, an address within the stack. */
1505 emit_stack_probe (rtx address
)
1507 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1509 MEM_VOLATILE_P (memref
) = 1;
1511 /* See if we have an insn to probe the stack. */
1512 #ifdef HAVE_probe_stack
1513 if (HAVE_probe_stack
)
1514 emit_insn (gen_probe_stack (memref
));
1517 emit_move_insn (memref
, const0_rtx
);
1520 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1521 FIRST is a constant and size is a Pmode RTX. These are offsets from
1522 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1523 or subtract them from the stack pointer. */
1525 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1527 #ifdef STACK_GROWS_DOWNWARD
1528 #define STACK_GROW_OP MINUS
1529 #define STACK_GROW_OPTAB sub_optab
1530 #define STACK_GROW_OFF(off) -(off)
1532 #define STACK_GROW_OP PLUS
1533 #define STACK_GROW_OPTAB add_optab
1534 #define STACK_GROW_OFF(off) (off)
1538 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1540 /* First ensure SIZE is Pmode. */
1541 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1542 size
= convert_to_mode (Pmode
, size
, 1);
1544 /* Next see if we have a function to check the stack. */
1545 if (stack_check_libfunc
)
1547 rtx addr
= memory_address (Pmode
,
1548 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1550 plus_constant (size
, first
)));
1551 emit_library_call (stack_check_libfunc
, LCT_NORMAL
, VOIDmode
, 1, addr
,
1556 /* Next see if we have an insn to check the stack. */
1557 #ifdef HAVE_check_stack
1558 if (HAVE_check_stack
)
1560 struct expand_operand ops
[1];
1561 rtx addr
= memory_address (Pmode
,
1562 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1564 plus_constant (size
, first
)));
1566 create_input_operand (&ops
[0], addr
, Pmode
);
1567 if (maybe_expand_insn (CODE_FOR_check_stack
, 1, ops
))
1572 /* Otherwise we have to generate explicit probes. If we have a constant
1573 small number of them to generate, that's the easy case. */
1574 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1576 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1579 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1580 it exceeds SIZE. If only one probe is needed, this will not
1581 generate any code. Then probe at FIRST + SIZE. */
1582 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1584 addr
= memory_address (Pmode
,
1585 plus_constant (stack_pointer_rtx
,
1586 STACK_GROW_OFF (first
+ i
)));
1587 emit_stack_probe (addr
);
1590 addr
= memory_address (Pmode
,
1591 plus_constant (stack_pointer_rtx
,
1592 STACK_GROW_OFF (first
+ isize
)));
1593 emit_stack_probe (addr
);
1596 /* In the variable case, do the same as above, but in a loop. Note that we
1597 must be extra careful with variables wrapping around because we might be
1598 at the very top (or the very bottom) of the address space and we have to
1599 be able to handle this case properly; in particular, we use an equality
1600 test for the loop condition. */
1603 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1604 rtx loop_lab
= gen_label_rtx ();
1605 rtx end_lab
= gen_label_rtx ();
1608 /* Step 1: round SIZE to the previous multiple of the interval. */
1610 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1612 = simplify_gen_binary (AND
, Pmode
, size
, GEN_INT (-PROBE_INTERVAL
));
1613 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1616 /* Step 2: compute initial and final value of the loop counter. */
1618 /* TEST_ADDR = SP + FIRST. */
1619 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1621 GEN_INT (first
)), NULL_RTX
);
1623 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1624 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1626 rounded_size_op
), NULL_RTX
);
1631 while (TEST_ADDR != LAST_ADDR)
1633 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1637 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1638 until it is equal to ROUNDED_SIZE. */
1640 emit_label (loop_lab
);
1642 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1643 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1646 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1647 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1648 GEN_INT (PROBE_INTERVAL
), test_addr
,
1651 gcc_assert (temp
== test_addr
);
1653 /* Probe at TEST_ADDR. */
1654 emit_stack_probe (test_addr
);
1656 emit_jump (loop_lab
);
1658 emit_label (end_lab
);
1661 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1662 that SIZE is equal to ROUNDED_SIZE. */
1664 /* TEMP = SIZE - ROUNDED_SIZE. */
1665 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1666 if (temp
!= const0_rtx
)
1670 if (CONST_INT_P (temp
))
1672 /* Use [base + disp} addressing mode if supported. */
1673 HOST_WIDE_INT offset
= INTVAL (temp
);
1674 addr
= memory_address (Pmode
,
1675 plus_constant (last_addr
,
1676 STACK_GROW_OFF (offset
)));
1680 /* Manual CSE if the difference is not known at compile-time. */
1681 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1682 addr
= memory_address (Pmode
,
1683 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1687 emit_stack_probe (addr
);
1692 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1693 while probing it. This pushes when SIZE is positive. SIZE need not
1694 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1695 by plus SIZE at the end. */
1698 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1700 /* We skip the probe for the first interval + a small dope of 4 words and
1701 probe that many bytes past the specified size to maintain a protection
1702 area at the botton of the stack. */
1703 const int dope
= 4 * UNITS_PER_WORD
;
1705 /* First ensure SIZE is Pmode. */
1706 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1707 size
= convert_to_mode (Pmode
, size
, 1);
1709 /* If we have a constant small number of probes to generate, that's the
1711 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1713 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1714 bool first_probe
= true;
1716 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1717 values of N from 1 until it exceeds SIZE. If only one probe is
1718 needed, this will not generate any code. Then adjust and probe
1719 to PROBE_INTERVAL + SIZE. */
1720 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1724 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1725 first_probe
= false;
1728 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1729 emit_stack_probe (stack_pointer_rtx
);
1733 anti_adjust_stack (plus_constant (size
, PROBE_INTERVAL
+ dope
));
1735 anti_adjust_stack (plus_constant (size
, PROBE_INTERVAL
- i
));
1736 emit_stack_probe (stack_pointer_rtx
);
1739 /* In the variable case, do the same as above, but in a loop. Note that we
1740 must be extra careful with variables wrapping around because we might be
1741 at the very top (or the very bottom) of the address space and we have to
1742 be able to handle this case properly; in particular, we use an equality
1743 test for the loop condition. */
1746 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1747 rtx loop_lab
= gen_label_rtx ();
1748 rtx end_lab
= gen_label_rtx ();
1751 /* Step 1: round SIZE to the previous multiple of the interval. */
1753 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1755 = simplify_gen_binary (AND
, Pmode
, size
, GEN_INT (-PROBE_INTERVAL
));
1756 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1759 /* Step 2: compute initial and final value of the loop counter. */
1761 /* SP = SP_0 + PROBE_INTERVAL. */
1762 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1764 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1765 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1767 rounded_size_op
), NULL_RTX
);
1772 while (SP != LAST_ADDR)
1774 SP = SP + PROBE_INTERVAL
1778 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1779 values of N from 1 until it is equal to ROUNDED_SIZE. */
1781 emit_label (loop_lab
);
1783 /* Jump to END_LAB if SP == LAST_ADDR. */
1784 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1787 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1788 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1789 emit_stack_probe (stack_pointer_rtx
);
1791 emit_jump (loop_lab
);
1793 emit_label (end_lab
);
1796 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1797 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1799 /* TEMP = SIZE - ROUNDED_SIZE. */
1800 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1801 if (temp
!= const0_rtx
)
1803 /* Manual CSE if the difference is not known at compile-time. */
1804 if (GET_CODE (temp
) != CONST_INT
)
1805 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1806 anti_adjust_stack (temp
);
1807 emit_stack_probe (stack_pointer_rtx
);
1811 /* Adjust back and account for the additional first interval. */
1813 adjust_stack (plus_constant (size
, PROBE_INTERVAL
+ dope
));
1815 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1818 /* Return an rtx representing the register or memory location
1819 in which a scalar value of data type VALTYPE
1820 was returned by a function call to function FUNC.
1821 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1822 function is known, otherwise 0.
1823 OUTGOING is 1 if on a machine with register windows this function
1824 should return the register in which the function will put its result
1828 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1829 int outgoing ATTRIBUTE_UNUSED
)
1833 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1836 && GET_MODE (val
) == BLKmode
)
1838 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1839 enum machine_mode tmpmode
;
1841 /* int_size_in_bytes can return -1. We don't need a check here
1842 since the value of bytes will then be large enough that no
1843 mode will match anyway. */
1845 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1846 tmpmode
!= VOIDmode
;
1847 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1849 /* Have we found a large enough mode? */
1850 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1854 /* No suitable mode found. */
1855 gcc_assert (tmpmode
!= VOIDmode
);
1857 PUT_MODE (val
, tmpmode
);
1862 /* Return an rtx representing the register or memory location
1863 in which a scalar value of mode MODE was returned by a library call. */
1866 hard_libcall_value (enum machine_mode mode
, rtx fun
)
1868 return targetm
.calls
.libcall_value (mode
, fun
);
1871 /* Look up the tree code for a given rtx code
1872 to provide the arithmetic operation for REAL_ARITHMETIC.
1873 The function returns an int because the caller may not know
1874 what `enum tree_code' means. */
1877 rtx_to_tree_code (enum rtx_code code
)
1879 enum tree_code tcode
;
1902 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1905 return ((int) tcode
);
1908 #include "gt-explow.h"