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 /* For addition we can safely permute the conversion and addition
388 operation if one operand is a constant and converting the constant
389 does not change it or if one operand is a constant and we are
390 using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0).
391 We can always safely permute them if we are making the address
393 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
394 || (GET_CODE (x
) == PLUS
395 && CONST_INT_P (XEXP (x
, 1))
396 && (XEXP (x
, 1) == convert_memory_address_addr_space
397 (to_mode
, XEXP (x
, 1), as
)
398 || POINTERS_EXTEND_UNSIGNED
< 0)))
399 return gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
400 convert_memory_address_addr_space
401 (to_mode
, XEXP (x
, 0), as
),
409 return convert_modes (to_mode
, from_mode
,
410 x
, POINTERS_EXTEND_UNSIGNED
);
411 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
414 /* Return something equivalent to X but valid as a memory address for something
415 of mode MODE in the named address space AS. When X is not itself valid,
416 this works by copying X or subexpressions of it into registers. */
419 memory_address_addr_space (enum machine_mode mode
, rtx x
, addr_space_t as
)
422 enum machine_mode address_mode
= targetm
.addr_space
.address_mode (as
);
424 x
= convert_memory_address_addr_space (address_mode
, x
, as
);
426 /* By passing constant addresses through registers
427 we get a chance to cse them. */
428 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
429 x
= force_reg (address_mode
, x
);
431 /* We get better cse by rejecting indirect addressing at this stage.
432 Let the combiner create indirect addresses where appropriate.
433 For now, generate the code so that the subexpressions useful to share
434 are visible. But not if cse won't be done! */
437 if (! cse_not_expected
&& !REG_P (x
))
438 x
= break_out_memory_refs (x
);
440 /* At this point, any valid address is accepted. */
441 if (memory_address_addr_space_p (mode
, x
, as
))
444 /* If it was valid before but breaking out memory refs invalidated it,
445 use it the old way. */
446 if (memory_address_addr_space_p (mode
, oldx
, as
))
452 /* Perform machine-dependent transformations on X
453 in certain cases. This is not necessary since the code
454 below can handle all possible cases, but machine-dependent
455 transformations can make better code. */
458 x
= targetm
.addr_space
.legitimize_address (x
, oldx
, mode
, as
);
459 if (orig_x
!= x
&& memory_address_addr_space_p (mode
, x
, as
))
463 /* PLUS and MULT can appear in special ways
464 as the result of attempts to make an address usable for indexing.
465 Usually they are dealt with by calling force_operand, below.
466 But a sum containing constant terms is special
467 if removing them makes the sum a valid address:
468 then we generate that address in a register
469 and index off of it. We do this because it often makes
470 shorter code, and because the addresses thus generated
471 in registers often become common subexpressions. */
472 if (GET_CODE (x
) == PLUS
)
474 rtx constant_term
= const0_rtx
;
475 rtx y
= eliminate_constant_term (x
, &constant_term
);
476 if (constant_term
== const0_rtx
477 || ! memory_address_addr_space_p (mode
, y
, as
))
478 x
= force_operand (x
, NULL_RTX
);
481 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
482 if (! memory_address_addr_space_p (mode
, y
, as
))
483 x
= force_operand (x
, NULL_RTX
);
489 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
490 x
= force_operand (x
, NULL_RTX
);
492 /* If we have a register that's an invalid address,
493 it must be a hard reg of the wrong class. Copy it to a pseudo. */
497 /* Last resort: copy the value to a register, since
498 the register is a valid address. */
500 x
= force_reg (address_mode
, x
);
505 gcc_assert (memory_address_addr_space_p (mode
, x
, as
));
506 /* If we didn't change the address, we are done. Otherwise, mark
507 a reg as a pointer if we have REG or REG + CONST_INT. */
511 mark_reg_pointer (x
, BITS_PER_UNIT
);
512 else if (GET_CODE (x
) == PLUS
513 && REG_P (XEXP (x
, 0))
514 && CONST_INT_P (XEXP (x
, 1)))
515 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
517 /* OLDX may have been the address on a temporary. Update the address
518 to indicate that X is now used. */
519 update_temp_slot_address (oldx
, x
);
524 /* Convert a mem ref into one with a valid memory address.
525 Pass through anything else unchanged. */
528 validize_mem (rtx ref
)
532 ref
= use_anchored_address (ref
);
533 if (memory_address_addr_space_p (GET_MODE (ref
), XEXP (ref
, 0),
534 MEM_ADDR_SPACE (ref
)))
537 /* Don't alter REF itself, since that is probably a stack slot. */
538 return replace_equiv_address (ref
, XEXP (ref
, 0));
541 /* If X is a memory reference to a member of an object block, try rewriting
542 it to use an anchor instead. Return the new memory reference on success
543 and the old one on failure. */
546 use_anchored_address (rtx x
)
549 HOST_WIDE_INT offset
;
551 if (!flag_section_anchors
)
557 /* Split the address into a base and offset. */
560 if (GET_CODE (base
) == CONST
561 && GET_CODE (XEXP (base
, 0)) == PLUS
562 && CONST_INT_P (XEXP (XEXP (base
, 0), 1)))
564 offset
+= INTVAL (XEXP (XEXP (base
, 0), 1));
565 base
= XEXP (XEXP (base
, 0), 0);
568 /* Check whether BASE is suitable for anchors. */
569 if (GET_CODE (base
) != SYMBOL_REF
570 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base
)
571 || SYMBOL_REF_ANCHOR_P (base
)
572 || SYMBOL_REF_BLOCK (base
) == NULL
573 || !targetm
.use_anchors_for_symbol_p (base
))
576 /* Decide where BASE is going to be. */
577 place_block_symbol (base
);
579 /* Get the anchor we need to use. */
580 offset
+= SYMBOL_REF_BLOCK_OFFSET (base
);
581 base
= get_section_anchor (SYMBOL_REF_BLOCK (base
), offset
,
582 SYMBOL_REF_TLS_MODEL (base
));
584 /* Work out the offset from the anchor. */
585 offset
-= SYMBOL_REF_BLOCK_OFFSET (base
);
587 /* If we're going to run a CSE pass, force the anchor into a register.
588 We will then be able to reuse registers for several accesses, if the
589 target costs say that that's worthwhile. */
590 if (!cse_not_expected
)
591 base
= force_reg (GET_MODE (base
), base
);
593 return replace_equiv_address (x
, plus_constant (base
, offset
));
596 /* Copy the value or contents of X to a new temp reg and return that reg. */
601 rtx temp
= gen_reg_rtx (GET_MODE (x
));
603 /* If not an operand, must be an address with PLUS and MULT so
604 do the computation. */
605 if (! general_operand (x
, VOIDmode
))
606 x
= force_operand (x
, temp
);
609 emit_move_insn (temp
, x
);
614 /* Like copy_to_reg but always give the new register mode Pmode
615 in case X is a constant. */
618 copy_addr_to_reg (rtx x
)
620 return copy_to_mode_reg (Pmode
, x
);
623 /* Like copy_to_reg but always give the new register mode MODE
624 in case X is a constant. */
627 copy_to_mode_reg (enum machine_mode mode
, rtx x
)
629 rtx temp
= gen_reg_rtx (mode
);
631 /* If not an operand, must be an address with PLUS and MULT so
632 do the computation. */
633 if (! general_operand (x
, VOIDmode
))
634 x
= force_operand (x
, temp
);
636 gcc_assert (GET_MODE (x
) == mode
|| GET_MODE (x
) == VOIDmode
);
638 emit_move_insn (temp
, x
);
642 /* Load X into a register if it is not already one.
643 Use mode MODE for the register.
644 X should be valid for mode MODE, but it may be a constant which
645 is valid for all integer modes; that's why caller must specify MODE.
647 The caller must not alter the value in the register we return,
648 since we mark it as a "constant" register. */
651 force_reg (enum machine_mode mode
, rtx x
)
658 if (general_operand (x
, mode
))
660 temp
= gen_reg_rtx (mode
);
661 insn
= emit_move_insn (temp
, x
);
665 temp
= force_operand (x
, NULL_RTX
);
667 insn
= get_last_insn ();
670 rtx temp2
= gen_reg_rtx (mode
);
671 insn
= emit_move_insn (temp2
, temp
);
676 /* Let optimizers know that TEMP's value never changes
677 and that X can be substituted for it. Don't get confused
678 if INSN set something else (such as a SUBREG of TEMP). */
680 && (set
= single_set (insn
)) != 0
681 && SET_DEST (set
) == temp
682 && ! rtx_equal_p (x
, SET_SRC (set
)))
683 set_unique_reg_note (insn
, REG_EQUAL
, x
);
685 /* Let optimizers know that TEMP is a pointer, and if so, the
686 known alignment of that pointer. */
689 if (GET_CODE (x
) == SYMBOL_REF
)
691 align
= BITS_PER_UNIT
;
692 if (SYMBOL_REF_DECL (x
) && DECL_P (SYMBOL_REF_DECL (x
)))
693 align
= DECL_ALIGN (SYMBOL_REF_DECL (x
));
695 else if (GET_CODE (x
) == LABEL_REF
)
696 align
= BITS_PER_UNIT
;
697 else if (GET_CODE (x
) == CONST
698 && GET_CODE (XEXP (x
, 0)) == PLUS
699 && GET_CODE (XEXP (XEXP (x
, 0), 0)) == SYMBOL_REF
700 && CONST_INT_P (XEXP (XEXP (x
, 0), 1)))
702 rtx s
= XEXP (XEXP (x
, 0), 0);
703 rtx c
= XEXP (XEXP (x
, 0), 1);
707 if (SYMBOL_REF_DECL (s
) && DECL_P (SYMBOL_REF_DECL (s
)))
708 sa
= DECL_ALIGN (SYMBOL_REF_DECL (s
));
714 ca
= ctz_hwi (INTVAL (c
)) * BITS_PER_UNIT
;
715 align
= MIN (sa
, ca
);
719 if (align
|| (MEM_P (x
) && MEM_POINTER (x
)))
720 mark_reg_pointer (temp
, align
);
726 /* If X is a memory ref, copy its contents to a new temp reg and return
727 that reg. Otherwise, return X. */
730 force_not_mem (rtx x
)
734 if (!MEM_P (x
) || GET_MODE (x
) == BLKmode
)
737 temp
= gen_reg_rtx (GET_MODE (x
));
740 REG_POINTER (temp
) = 1;
742 emit_move_insn (temp
, x
);
746 /* Copy X to TARGET (if it's nonzero and a reg)
747 or to a new temp reg and return that reg.
748 MODE is the mode to use for X in case it is a constant. */
751 copy_to_suggested_reg (rtx x
, rtx target
, enum machine_mode mode
)
755 if (target
&& REG_P (target
))
758 temp
= gen_reg_rtx (mode
);
760 emit_move_insn (temp
, x
);
764 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
765 PUNSIGNEDP points to the signedness of the type and may be adjusted
766 to show what signedness to use on extension operations.
768 FOR_RETURN is nonzero if the caller is promoting the return value
769 of FNDECL, else it is for promoting args. */
772 promote_function_mode (const_tree type
, enum machine_mode mode
, int *punsignedp
,
773 const_tree funtype
, int for_return
)
775 /* Called without a type node for a libcall. */
776 if (type
== NULL_TREE
)
778 if (INTEGRAL_MODE_P (mode
))
779 return targetm
.calls
.promote_function_mode (NULL_TREE
, mode
,
786 switch (TREE_CODE (type
))
788 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
789 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
790 case POINTER_TYPE
: case REFERENCE_TYPE
:
791 return targetm
.calls
.promote_function_mode (type
, mode
, punsignedp
, funtype
,
798 /* Return the mode to use to store a scalar of TYPE and MODE.
799 PUNSIGNEDP points to the signedness of the type and may be adjusted
800 to show what signedness to use on extension operations. */
803 promote_mode (const_tree type ATTRIBUTE_UNUSED
, enum machine_mode mode
,
804 int *punsignedp ATTRIBUTE_UNUSED
)
811 /* For libcalls this is invoked without TYPE from the backends
812 TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
814 if (type
== NULL_TREE
)
817 /* FIXME: this is the same logic that was there until GCC 4.4, but we
818 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
819 is not defined. The affected targets are M32C, S390, SPARC. */
821 code
= TREE_CODE (type
);
822 unsignedp
= *punsignedp
;
826 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
827 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
828 PROMOTE_MODE (mode
, unsignedp
, type
);
829 *punsignedp
= unsignedp
;
833 #ifdef POINTERS_EXTEND_UNSIGNED
836 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
837 return targetm
.addr_space
.address_mode
838 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
851 /* Use one of promote_mode or promote_function_mode to find the promoted
852 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
853 of DECL after promotion. */
856 promote_decl_mode (const_tree decl
, int *punsignedp
)
858 tree type
= TREE_TYPE (decl
);
859 int unsignedp
= TYPE_UNSIGNED (type
);
860 enum machine_mode mode
= DECL_MODE (decl
);
861 enum machine_mode pmode
;
863 if (TREE_CODE (decl
) == RESULT_DECL
864 || TREE_CODE (decl
) == PARM_DECL
)
865 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
866 TREE_TYPE (current_function_decl
), 2);
868 pmode
= promote_mode (type
, mode
, &unsignedp
);
871 *punsignedp
= unsignedp
;
876 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
877 This pops when ADJUST is positive. ADJUST need not be constant. */
880 adjust_stack (rtx adjust
)
884 if (adjust
== const0_rtx
)
887 /* We expect all variable sized adjustments to be multiple of
888 PREFERRED_STACK_BOUNDARY. */
889 if (CONST_INT_P (adjust
))
890 stack_pointer_delta
-= INTVAL (adjust
);
892 temp
= expand_binop (Pmode
,
893 #ifdef STACK_GROWS_DOWNWARD
898 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
901 if (temp
!= stack_pointer_rtx
)
902 emit_move_insn (stack_pointer_rtx
, temp
);
905 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
906 This pushes when ADJUST is positive. ADJUST need not be constant. */
909 anti_adjust_stack (rtx adjust
)
913 if (adjust
== const0_rtx
)
916 /* We expect all variable sized adjustments to be multiple of
917 PREFERRED_STACK_BOUNDARY. */
918 if (CONST_INT_P (adjust
))
919 stack_pointer_delta
+= INTVAL (adjust
);
921 temp
= expand_binop (Pmode
,
922 #ifdef STACK_GROWS_DOWNWARD
927 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
930 if (temp
!= stack_pointer_rtx
)
931 emit_move_insn (stack_pointer_rtx
, temp
);
934 /* Round the size of a block to be pushed up to the boundary required
935 by this machine. SIZE is the desired size, which need not be constant. */
938 round_push (rtx size
)
940 rtx align_rtx
, alignm1_rtx
;
942 if (!SUPPORTS_STACK_ALIGNMENT
943 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
945 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
950 if (CONST_INT_P (size
))
952 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
954 if (INTVAL (size
) != new_size
)
955 size
= GEN_INT (new_size
);
959 align_rtx
= GEN_INT (align
);
960 alignm1_rtx
= GEN_INT (align
- 1);
964 /* If crtl->preferred_stack_boundary might still grow, use
965 virtual_preferred_stack_boundary_rtx instead. This will be
966 substituted by the right value in vregs pass and optimized
968 align_rtx
= virtual_preferred_stack_boundary_rtx
;
969 alignm1_rtx
= force_operand (plus_constant (align_rtx
, -1), NULL_RTX
);
972 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
973 but we know it can't. So add ourselves and then do
975 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
976 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
977 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
979 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
984 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
985 to a previously-created save area. If no save area has been allocated,
986 this function will allocate one. If a save area is specified, it
987 must be of the proper mode. */
990 emit_stack_save (enum save_level save_level
, rtx
*psave
)
993 /* The default is that we use a move insn and save in a Pmode object. */
994 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
995 enum machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
997 /* See if this machine has anything special to do for this kind of save. */
1000 #ifdef HAVE_save_stack_block
1002 if (HAVE_save_stack_block
)
1003 fcn
= gen_save_stack_block
;
1006 #ifdef HAVE_save_stack_function
1008 if (HAVE_save_stack_function
)
1009 fcn
= gen_save_stack_function
;
1012 #ifdef HAVE_save_stack_nonlocal
1014 if (HAVE_save_stack_nonlocal
)
1015 fcn
= gen_save_stack_nonlocal
;
1022 /* If there is no save area and we have to allocate one, do so. Otherwise
1023 verify the save area is the proper mode. */
1027 if (mode
!= VOIDmode
)
1029 if (save_level
== SAVE_NONLOCAL
)
1030 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1032 *psave
= sa
= gen_reg_rtx (mode
);
1036 do_pending_stack_adjust ();
1038 sa
= validize_mem (sa
);
1039 emit_insn (fcn (sa
, stack_pointer_rtx
));
1042 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1043 area made by emit_stack_save. If it is zero, we have nothing to do. */
1046 emit_stack_restore (enum save_level save_level
, rtx sa
)
1048 /* The default is that we use a move insn. */
1049 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
1051 /* See if this machine has anything special to do for this kind of save. */
1054 #ifdef HAVE_restore_stack_block
1056 if (HAVE_restore_stack_block
)
1057 fcn
= gen_restore_stack_block
;
1060 #ifdef HAVE_restore_stack_function
1062 if (HAVE_restore_stack_function
)
1063 fcn
= gen_restore_stack_function
;
1066 #ifdef HAVE_restore_stack_nonlocal
1068 if (HAVE_restore_stack_nonlocal
)
1069 fcn
= gen_restore_stack_nonlocal
;
1078 sa
= validize_mem (sa
);
1079 /* These clobbers prevent the scheduler from moving
1080 references to variable arrays below the code
1081 that deletes (pops) the arrays. */
1082 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1083 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1086 discard_pending_stack_adjust ();
1088 emit_insn (fcn (stack_pointer_rtx
, sa
));
1091 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1092 function. This function should be called whenever we allocate or
1093 deallocate dynamic stack space. */
1096 update_nonlocal_goto_save_area (void)
1101 /* The nonlocal_goto_save_area object is an array of N pointers. The
1102 first one is used for the frame pointer save; the rest are sized by
1103 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1104 of the stack save area slots. */
1105 t_save
= build4 (ARRAY_REF
,
1106 TREE_TYPE (TREE_TYPE (cfun
->nonlocal_goto_save_area
)),
1107 cfun
->nonlocal_goto_save_area
,
1108 integer_one_node
, NULL_TREE
, NULL_TREE
);
1109 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1111 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1114 /* Return an rtx representing the address of an area of memory dynamically
1115 pushed on the stack.
1117 Any required stack pointer alignment is preserved.
1119 SIZE is an rtx representing the size of the area.
1121 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1122 parameter may be zero. If so, a proper value will be extracted
1123 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1125 REQUIRED_ALIGN is the alignment (in bits) required for the region
1128 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1129 stack space allocated by the generated code cannot be added with itself
1130 in the course of the execution of the function. It is always safe to
1131 pass FALSE here and the following criterion is sufficient in order to
1132 pass TRUE: every path in the CFG that starts at the allocation point and
1133 loops to it executes the associated deallocation code. */
1136 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1137 unsigned required_align
, bool cannot_accumulate
)
1139 HOST_WIDE_INT stack_usage_size
= -1;
1140 rtx final_label
, final_target
, target
;
1141 unsigned extra_align
= 0;
1144 /* If we're asking for zero bytes, it doesn't matter what we point
1145 to since we can't dereference it. But return a reasonable
1147 if (size
== const0_rtx
)
1148 return virtual_stack_dynamic_rtx
;
1150 /* Otherwise, show we're calling alloca or equivalent. */
1151 cfun
->calls_alloca
= 1;
1153 /* If stack usage info is requested, look into the size we are passed.
1154 We need to do so this early to avoid the obfuscation that may be
1155 introduced later by the various alignment operations. */
1156 if (flag_stack_usage_info
)
1158 if (CONST_INT_P (size
))
1159 stack_usage_size
= INTVAL (size
);
1160 else if (REG_P (size
))
1162 /* Look into the last emitted insn and see if we can deduce
1163 something for the register. */
1164 rtx insn
, set
, note
;
1165 insn
= get_last_insn ();
1166 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1168 if (CONST_INT_P (SET_SRC (set
)))
1169 stack_usage_size
= INTVAL (SET_SRC (set
));
1170 else if ((note
= find_reg_equal_equiv_note (insn
))
1171 && CONST_INT_P (XEXP (note
, 0)))
1172 stack_usage_size
= INTVAL (XEXP (note
, 0));
1176 /* If the size is not constant, we can't say anything. */
1177 if (stack_usage_size
== -1)
1179 current_function_has_unbounded_dynamic_stack_size
= 1;
1180 stack_usage_size
= 0;
1184 /* Ensure the size is in the proper mode. */
1185 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1186 size
= convert_to_mode (Pmode
, size
, 1);
1188 /* Adjust SIZE_ALIGN, if needed. */
1189 if (CONST_INT_P (size
))
1191 unsigned HOST_WIDE_INT lsb
;
1193 lsb
= INTVAL (size
);
1196 /* Watch out for overflow truncating to "unsigned". */
1197 if (lsb
> UINT_MAX
/ BITS_PER_UNIT
)
1198 size_align
= 1u << (HOST_BITS_PER_INT
- 1);
1200 size_align
= (unsigned)lsb
* BITS_PER_UNIT
;
1202 else if (size_align
< BITS_PER_UNIT
)
1203 size_align
= BITS_PER_UNIT
;
1205 /* We can't attempt to minimize alignment necessary, because we don't
1206 know the final value of preferred_stack_boundary yet while executing
1208 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1209 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1211 /* We will need to ensure that the address we return is aligned to
1212 REQUIRED_ALIGN. If STACK_DYNAMIC_OFFSET is defined, we don't
1213 always know its final value at this point in the compilation (it
1214 might depend on the size of the outgoing parameter lists, for
1215 example), so we must align the value to be returned in that case.
1216 (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
1217 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1218 We must also do an alignment operation on the returned value if
1219 the stack pointer alignment is less strict than REQUIRED_ALIGN.
1221 If we have to align, we must leave space in SIZE for the hole
1222 that might result from the alignment operation. */
1224 must_align
= (crtl
->preferred_stack_boundary
< required_align
);
1227 if (required_align
> PREFERRED_STACK_BOUNDARY
)
1228 extra_align
= PREFERRED_STACK_BOUNDARY
;
1229 else if (required_align
> STACK_BOUNDARY
)
1230 extra_align
= STACK_BOUNDARY
;
1232 extra_align
= BITS_PER_UNIT
;
1235 /* ??? STACK_POINTER_OFFSET is always defined now. */
1236 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
1238 extra_align
= BITS_PER_UNIT
;
1243 unsigned extra
= (required_align
- extra_align
) / BITS_PER_UNIT
;
1245 size
= plus_constant (size
, extra
);
1246 size
= force_operand (size
, NULL_RTX
);
1248 if (flag_stack_usage_info
)
1249 stack_usage_size
+= extra
;
1251 if (extra
&& size_align
> extra_align
)
1252 size_align
= extra_align
;
1255 /* Round the size to a multiple of the required stack alignment.
1256 Since the stack if presumed to be rounded before this allocation,
1257 this will maintain the required alignment.
1259 If the stack grows downward, we could save an insn by subtracting
1260 SIZE from the stack pointer and then aligning the stack pointer.
1261 The problem with this is that the stack pointer may be unaligned
1262 between the execution of the subtraction and alignment insns and
1263 some machines do not allow this. Even on those that do, some
1264 signal handlers malfunction if a signal should occur between those
1265 insns. Since this is an extremely rare event, we have no reliable
1266 way of knowing which systems have this problem. So we avoid even
1267 momentarily mis-aligning the stack. */
1268 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1270 size
= round_push (size
);
1272 if (flag_stack_usage_info
)
1274 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1275 stack_usage_size
= (stack_usage_size
+ align
- 1) / align
* align
;
1279 target
= gen_reg_rtx (Pmode
);
1281 /* The size is supposed to be fully adjusted at this point so record it
1282 if stack usage info is requested. */
1283 if (flag_stack_usage_info
)
1285 current_function_dynamic_stack_size
+= stack_usage_size
;
1287 /* ??? This is gross but the only safe stance in the absence
1288 of stack usage oriented flow analysis. */
1289 if (!cannot_accumulate
)
1290 current_function_has_unbounded_dynamic_stack_size
= 1;
1293 final_label
= NULL_RTX
;
1294 final_target
= NULL_RTX
;
1296 /* If we are splitting the stack, we need to ask the backend whether
1297 there is enough room on the current stack. If there isn't, or if
1298 the backend doesn't know how to tell is, then we need to call a
1299 function to allocate memory in some other way. This memory will
1300 be released when we release the current stack segment. The
1301 effect is that stack allocation becomes less efficient, but at
1302 least it doesn't cause a stack overflow. */
1303 if (flag_split_stack
)
1305 rtx available_label
, ask
, space
, func
;
1307 available_label
= NULL_RTX
;
1309 #ifdef HAVE_split_stack_space_check
1310 if (HAVE_split_stack_space_check
)
1312 available_label
= gen_label_rtx ();
1314 /* This instruction will branch to AVAILABLE_LABEL if there
1315 are SIZE bytes available on the stack. */
1316 emit_insn (gen_split_stack_space_check (size
, available_label
));
1320 /* The __morestack_allocate_stack_space function will allocate
1321 memory using malloc. If the alignment of the memory returned
1322 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1323 make sure we allocate enough space. */
1324 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1328 ask
= expand_binop (Pmode
, add_optab
, size
,
1329 GEN_INT (required_align
/ BITS_PER_UNIT
- 1),
1330 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1334 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1336 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1339 if (available_label
== NULL_RTX
)
1342 final_target
= gen_reg_rtx (Pmode
);
1344 emit_move_insn (final_target
, space
);
1346 final_label
= gen_label_rtx ();
1347 emit_jump (final_label
);
1349 emit_label (available_label
);
1352 do_pending_stack_adjust ();
1354 /* We ought to be called always on the toplevel and stack ought to be aligned
1356 gcc_assert (!(stack_pointer_delta
1357 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1359 /* If needed, check that we have the required amount of stack. Take into
1360 account what has already been checked. */
1361 if (STACK_CHECK_MOVING_SP
)
1363 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1364 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1366 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1367 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1369 /* Perform the required allocation from the stack. Some systems do
1370 this differently than simply incrementing/decrementing from the
1371 stack pointer, such as acquiring the space by calling malloc(). */
1372 #ifdef HAVE_allocate_stack
1373 if (HAVE_allocate_stack
)
1375 struct expand_operand ops
[2];
1376 /* We don't have to check against the predicate for operand 0 since
1377 TARGET is known to be a pseudo of the proper mode, which must
1378 be valid for the operand. */
1379 create_fixed_operand (&ops
[0], target
);
1380 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1381 expand_insn (CODE_FOR_allocate_stack
, 2, ops
);
1386 int saved_stack_pointer_delta
;
1388 #ifndef STACK_GROWS_DOWNWARD
1389 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1392 /* Check stack bounds if necessary. */
1393 if (crtl
->limit_stack
)
1396 rtx space_available
= gen_label_rtx ();
1397 #ifdef STACK_GROWS_DOWNWARD
1398 available
= expand_binop (Pmode
, sub_optab
,
1399 stack_pointer_rtx
, stack_limit_rtx
,
1400 NULL_RTX
, 1, OPTAB_WIDEN
);
1402 available
= expand_binop (Pmode
, sub_optab
,
1403 stack_limit_rtx
, stack_pointer_rtx
,
1404 NULL_RTX
, 1, OPTAB_WIDEN
);
1406 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1410 emit_insn (gen_trap ());
1413 error ("stack limits not supported on this target");
1415 emit_label (space_available
);
1418 saved_stack_pointer_delta
= stack_pointer_delta
;
1419 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1420 anti_adjust_stack_and_probe (size
, false);
1422 anti_adjust_stack (size
);
1423 /* Even if size is constant, don't modify stack_pointer_delta.
1424 The constant size alloca should preserve
1425 crtl->preferred_stack_boundary alignment. */
1426 stack_pointer_delta
= saved_stack_pointer_delta
;
1428 #ifdef STACK_GROWS_DOWNWARD
1429 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1433 /* Finish up the split stack handling. */
1434 if (final_label
!= NULL_RTX
)
1436 gcc_assert (flag_split_stack
);
1437 emit_move_insn (final_target
, target
);
1438 emit_label (final_label
);
1439 target
= final_target
;
1444 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1445 but we know it can't. So add ourselves and then do
1447 target
= expand_binop (Pmode
, add_optab
, target
,
1448 GEN_INT (required_align
/ BITS_PER_UNIT
- 1),
1449 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1450 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1451 GEN_INT (required_align
/ BITS_PER_UNIT
),
1453 target
= expand_mult (Pmode
, target
,
1454 GEN_INT (required_align
/ BITS_PER_UNIT
),
1458 /* Now that we've committed to a return value, mark its alignment. */
1459 mark_reg_pointer (target
, required_align
);
1461 /* Record the new stack level for nonlocal gotos. */
1462 if (cfun
->nonlocal_goto_save_area
!= 0)
1463 update_nonlocal_goto_save_area ();
1468 /* A front end may want to override GCC's stack checking by providing a
1469 run-time routine to call to check the stack, so provide a mechanism for
1470 calling that routine. */
1472 static GTY(()) rtx stack_check_libfunc
;
1475 set_stack_check_libfunc (const char *libfunc_name
)
1477 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1478 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1481 /* Emit one stack probe at ADDRESS, an address within the stack. */
1484 emit_stack_probe (rtx address
)
1486 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1488 MEM_VOLATILE_P (memref
) = 1;
1490 /* See if we have an insn to probe the stack. */
1491 #ifdef HAVE_probe_stack
1492 if (HAVE_probe_stack
)
1493 emit_insn (gen_probe_stack (memref
));
1496 emit_move_insn (memref
, const0_rtx
);
1499 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1500 FIRST is a constant and size is a Pmode RTX. These are offsets from
1501 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1502 or subtract them from the stack pointer. */
1504 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1506 #ifdef STACK_GROWS_DOWNWARD
1507 #define STACK_GROW_OP MINUS
1508 #define STACK_GROW_OPTAB sub_optab
1509 #define STACK_GROW_OFF(off) -(off)
1511 #define STACK_GROW_OP PLUS
1512 #define STACK_GROW_OPTAB add_optab
1513 #define STACK_GROW_OFF(off) (off)
1517 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1519 /* First ensure SIZE is Pmode. */
1520 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1521 size
= convert_to_mode (Pmode
, size
, 1);
1523 /* Next see if we have a function to check the stack. */
1524 if (stack_check_libfunc
)
1526 rtx addr
= memory_address (Pmode
,
1527 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1529 plus_constant (size
, first
)));
1530 emit_library_call (stack_check_libfunc
, LCT_NORMAL
, VOIDmode
, 1, addr
,
1535 /* Next see if we have an insn to check the stack. */
1536 #ifdef HAVE_check_stack
1537 if (HAVE_check_stack
)
1539 struct expand_operand ops
[1];
1540 rtx addr
= memory_address (Pmode
,
1541 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1543 plus_constant (size
, first
)));
1545 create_input_operand (&ops
[0], addr
, Pmode
);
1546 if (maybe_expand_insn (CODE_FOR_check_stack
, 1, ops
))
1551 /* Otherwise we have to generate explicit probes. If we have a constant
1552 small number of them to generate, that's the easy case. */
1553 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1555 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1558 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1559 it exceeds SIZE. If only one probe is needed, this will not
1560 generate any code. Then probe at FIRST + SIZE. */
1561 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1563 addr
= memory_address (Pmode
,
1564 plus_constant (stack_pointer_rtx
,
1565 STACK_GROW_OFF (first
+ i
)));
1566 emit_stack_probe (addr
);
1569 addr
= memory_address (Pmode
,
1570 plus_constant (stack_pointer_rtx
,
1571 STACK_GROW_OFF (first
+ isize
)));
1572 emit_stack_probe (addr
);
1575 /* In the variable case, do the same as above, but in a loop. Note that we
1576 must be extra careful with variables wrapping around because we might be
1577 at the very top (or the very bottom) of the address space and we have to
1578 be able to handle this case properly; in particular, we use an equality
1579 test for the loop condition. */
1582 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1583 rtx loop_lab
= gen_label_rtx ();
1584 rtx end_lab
= gen_label_rtx ();
1587 /* Step 1: round SIZE to the previous multiple of the interval. */
1589 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1591 = simplify_gen_binary (AND
, Pmode
, size
, GEN_INT (-PROBE_INTERVAL
));
1592 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1595 /* Step 2: compute initial and final value of the loop counter. */
1597 /* TEST_ADDR = SP + FIRST. */
1598 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1600 GEN_INT (first
)), NULL_RTX
);
1602 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1603 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1605 rounded_size_op
), NULL_RTX
);
1610 while (TEST_ADDR != LAST_ADDR)
1612 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1616 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1617 until it is equal to ROUNDED_SIZE. */
1619 emit_label (loop_lab
);
1621 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1622 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1625 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1626 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1627 GEN_INT (PROBE_INTERVAL
), test_addr
,
1630 gcc_assert (temp
== test_addr
);
1632 /* Probe at TEST_ADDR. */
1633 emit_stack_probe (test_addr
);
1635 emit_jump (loop_lab
);
1637 emit_label (end_lab
);
1640 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1641 that SIZE is equal to ROUNDED_SIZE. */
1643 /* TEMP = SIZE - ROUNDED_SIZE. */
1644 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1645 if (temp
!= const0_rtx
)
1649 if (CONST_INT_P (temp
))
1651 /* Use [base + disp} addressing mode if supported. */
1652 HOST_WIDE_INT offset
= INTVAL (temp
);
1653 addr
= memory_address (Pmode
,
1654 plus_constant (last_addr
,
1655 STACK_GROW_OFF (offset
)));
1659 /* Manual CSE if the difference is not known at compile-time. */
1660 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1661 addr
= memory_address (Pmode
,
1662 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1666 emit_stack_probe (addr
);
1671 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1672 while probing it. This pushes when SIZE is positive. SIZE need not
1673 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1674 by plus SIZE at the end. */
1677 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1679 /* We skip the probe for the first interval + a small dope of 4 words and
1680 probe that many bytes past the specified size to maintain a protection
1681 area at the botton of the stack. */
1682 const int dope
= 4 * UNITS_PER_WORD
;
1684 /* First ensure SIZE is Pmode. */
1685 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1686 size
= convert_to_mode (Pmode
, size
, 1);
1688 /* If we have a constant small number of probes to generate, that's the
1690 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1692 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1693 bool first_probe
= true;
1695 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1696 values of N from 1 until it exceeds SIZE. If only one probe is
1697 needed, this will not generate any code. Then adjust and probe
1698 to PROBE_INTERVAL + SIZE. */
1699 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1703 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1704 first_probe
= false;
1707 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1708 emit_stack_probe (stack_pointer_rtx
);
1712 anti_adjust_stack (plus_constant (size
, PROBE_INTERVAL
+ dope
));
1714 anti_adjust_stack (plus_constant (size
, PROBE_INTERVAL
- i
));
1715 emit_stack_probe (stack_pointer_rtx
);
1718 /* In the variable case, do the same as above, but in a loop. Note that we
1719 must be extra careful with variables wrapping around because we might be
1720 at the very top (or the very bottom) of the address space and we have to
1721 be able to handle this case properly; in particular, we use an equality
1722 test for the loop condition. */
1725 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1726 rtx loop_lab
= gen_label_rtx ();
1727 rtx end_lab
= gen_label_rtx ();
1730 /* Step 1: round SIZE to the previous multiple of the interval. */
1732 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1734 = simplify_gen_binary (AND
, Pmode
, size
, GEN_INT (-PROBE_INTERVAL
));
1735 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1738 /* Step 2: compute initial and final value of the loop counter. */
1740 /* SP = SP_0 + PROBE_INTERVAL. */
1741 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1743 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1744 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1746 rounded_size_op
), NULL_RTX
);
1751 while (SP != LAST_ADDR)
1753 SP = SP + PROBE_INTERVAL
1757 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1758 values of N from 1 until it is equal to ROUNDED_SIZE. */
1760 emit_label (loop_lab
);
1762 /* Jump to END_LAB if SP == LAST_ADDR. */
1763 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1766 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1767 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1768 emit_stack_probe (stack_pointer_rtx
);
1770 emit_jump (loop_lab
);
1772 emit_label (end_lab
);
1775 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1776 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1778 /* TEMP = SIZE - ROUNDED_SIZE. */
1779 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1780 if (temp
!= const0_rtx
)
1782 /* Manual CSE if the difference is not known at compile-time. */
1783 if (GET_CODE (temp
) != CONST_INT
)
1784 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1785 anti_adjust_stack (temp
);
1786 emit_stack_probe (stack_pointer_rtx
);
1790 /* Adjust back and account for the additional first interval. */
1792 adjust_stack (plus_constant (size
, PROBE_INTERVAL
+ dope
));
1794 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1797 /* Return an rtx representing the register or memory location
1798 in which a scalar value of data type VALTYPE
1799 was returned by a function call to function FUNC.
1800 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1801 function is known, otherwise 0.
1802 OUTGOING is 1 if on a machine with register windows this function
1803 should return the register in which the function will put its result
1807 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1808 int outgoing ATTRIBUTE_UNUSED
)
1812 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1815 && GET_MODE (val
) == BLKmode
)
1817 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1818 enum machine_mode tmpmode
;
1820 /* int_size_in_bytes can return -1. We don't need a check here
1821 since the value of bytes will then be large enough that no
1822 mode will match anyway. */
1824 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1825 tmpmode
!= VOIDmode
;
1826 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1828 /* Have we found a large enough mode? */
1829 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1833 /* No suitable mode found. */
1834 gcc_assert (tmpmode
!= VOIDmode
);
1836 PUT_MODE (val
, tmpmode
);
1841 /* Return an rtx representing the register or memory location
1842 in which a scalar value of mode MODE was returned by a library call. */
1845 hard_libcall_value (enum machine_mode mode
, rtx fun
)
1847 return targetm
.calls
.libcall_value (mode
, fun
);
1850 /* Look up the tree code for a given rtx code
1851 to provide the arithmetic operation for REAL_ARITHMETIC.
1852 The function returns an int because the caller may not know
1853 what `enum tree_code' means. */
1856 rtx_to_tree_code (enum rtx_code code
)
1858 enum tree_code tcode
;
1881 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1884 return ((int) tcode
);
1887 #include "gt-explow.h"