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"
45 static rtx
break_out_memory_refs (rtx
);
48 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
51 trunc_int_for_mode (HOST_WIDE_INT c
, enum machine_mode mode
)
53 int width
= GET_MODE_BITSIZE (mode
);
55 /* You want to truncate to a _what_? */
56 gcc_assert (SCALAR_INT_MODE_P (mode
));
58 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
60 return c
& 1 ? STORE_FLAG_VALUE
: 0;
62 /* Sign-extend for the requested mode. */
64 if (width
< HOST_BITS_PER_WIDE_INT
)
66 HOST_WIDE_INT sign
= 1;
76 /* Return an rtx for the sum of X and the integer C. */
79 plus_constant (rtx x
, HOST_WIDE_INT c
)
83 enum machine_mode mode
;
99 return GEN_INT (INTVAL (x
) + c
);
103 unsigned HOST_WIDE_INT l1
= CONST_DOUBLE_LOW (x
);
104 HOST_WIDE_INT h1
= CONST_DOUBLE_HIGH (x
);
105 unsigned HOST_WIDE_INT l2
= c
;
106 HOST_WIDE_INT h2
= c
< 0 ? ~0 : 0;
107 unsigned HOST_WIDE_INT lv
;
110 add_double (l1
, h1
, l2
, h2
, &lv
, &hv
);
112 return immed_double_const (lv
, hv
, VOIDmode
);
116 /* If this is a reference to the constant pool, try replacing it with
117 a reference to a new constant. If the resulting address isn't
118 valid, don't return it because we have no way to validize it. */
119 if (GET_CODE (XEXP (x
, 0)) == SYMBOL_REF
120 && CONSTANT_POOL_ADDRESS_P (XEXP (x
, 0)))
123 = force_const_mem (GET_MODE (x
),
124 plus_constant (get_pool_constant (XEXP (x
, 0)),
126 if (memory_address_p (GET_MODE (tem
), XEXP (tem
, 0)))
132 /* If adding to something entirely constant, set a flag
133 so that we can add a CONST around the result. */
144 /* The interesting case is adding the integer to a sum.
145 Look for constant term in the sum and combine
146 with C. For an integer constant term, we make a combined
147 integer. For a constant term that is not an explicit integer,
148 we cannot really combine, but group them together anyway.
150 Restart or use a recursive call in case the remaining operand is
151 something that we handle specially, such as a SYMBOL_REF.
153 We may not immediately return from the recursive call here, lest
154 all_constant gets lost. */
156 if (CONST_INT_P (XEXP (x
, 1)))
158 c
+= INTVAL (XEXP (x
, 1));
160 if (GET_MODE (x
) != VOIDmode
)
161 c
= trunc_int_for_mode (c
, GET_MODE (x
));
166 else if (CONSTANT_P (XEXP (x
, 1)))
168 x
= gen_rtx_PLUS (mode
, XEXP (x
, 0), plus_constant (XEXP (x
, 1), c
));
171 else if (find_constant_term_loc (&y
))
173 /* We need to be careful since X may be shared and we can't
174 modify it in place. */
175 rtx copy
= copy_rtx (x
);
176 rtx
*const_loc
= find_constant_term_loc (©
);
178 *const_loc
= plus_constant (*const_loc
, c
);
189 x
= gen_rtx_PLUS (mode
, x
, GEN_INT (c
));
191 if (GET_CODE (x
) == SYMBOL_REF
|| GET_CODE (x
) == LABEL_REF
)
193 else if (all_constant
)
194 return gen_rtx_CONST (mode
, x
);
199 /* If X is a sum, return a new sum like X but lacking any constant terms.
200 Add all the removed constant terms into *CONSTPTR.
201 X itself is not altered. The result != X if and only if
202 it is not isomorphic to X. */
205 eliminate_constant_term (rtx x
, rtx
*constptr
)
210 if (GET_CODE (x
) != PLUS
)
213 /* First handle constants appearing at this level explicitly. */
214 if (CONST_INT_P (XEXP (x
, 1))
215 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
), *constptr
,
217 && CONST_INT_P (tem
))
220 return eliminate_constant_term (XEXP (x
, 0), constptr
);
224 x0
= eliminate_constant_term (XEXP (x
, 0), &tem
);
225 x1
= eliminate_constant_term (XEXP (x
, 1), &tem
);
226 if ((x1
!= XEXP (x
, 1) || x0
!= XEXP (x
, 0))
227 && 0 != (tem
= simplify_binary_operation (PLUS
, GET_MODE (x
),
229 && CONST_INT_P (tem
))
232 return gen_rtx_PLUS (GET_MODE (x
), x0
, x1
);
238 /* Return an rtx for the size in bytes of the value of EXP. */
245 if (TREE_CODE (exp
) == WITH_SIZE_EXPR
)
246 size
= TREE_OPERAND (exp
, 1);
249 size
= tree_expr_size (exp
);
251 gcc_assert (size
== SUBSTITUTE_PLACEHOLDER_IN_EXPR (size
, exp
));
254 return expand_expr (size
, NULL_RTX
, TYPE_MODE (sizetype
), EXPAND_NORMAL
);
257 /* Return a wide integer for the size in bytes of the value of EXP, or -1
258 if the size can vary or is larger than an integer. */
261 int_expr_size (tree exp
)
265 if (TREE_CODE (exp
) == WITH_SIZE_EXPR
)
266 size
= TREE_OPERAND (exp
, 1);
269 size
= tree_expr_size (exp
);
273 if (size
== 0 || !host_integerp (size
, 0))
276 return tree_low_cst (size
, 0);
279 /* Return a copy of X in which all memory references
280 and all constants that involve symbol refs
281 have been replaced with new temporary registers.
282 Also emit code to load the memory locations and constants
283 into those registers.
285 If X contains no such constants or memory references,
286 X itself (not a copy) is returned.
288 If a constant is found in the address that is not a legitimate constant
289 in an insn, it is left alone in the hope that it might be valid in the
292 X may contain no arithmetic except addition, subtraction and multiplication.
293 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
296 break_out_memory_refs (rtx x
)
299 || (CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
)
300 && GET_MODE (x
) != VOIDmode
))
301 x
= force_reg (GET_MODE (x
), x
);
302 else if (GET_CODE (x
) == PLUS
|| GET_CODE (x
) == MINUS
303 || GET_CODE (x
) == MULT
)
305 rtx op0
= break_out_memory_refs (XEXP (x
, 0));
306 rtx op1
= break_out_memory_refs (XEXP (x
, 1));
308 if (op0
!= XEXP (x
, 0) || op1
!= XEXP (x
, 1))
309 x
= simplify_gen_binary (GET_CODE (x
), GET_MODE (x
), op0
, op1
);
315 /* Given X, a memory address in address space AS' pointer mode, convert it to
316 an address in the address space's address mode, or vice versa (TO_MODE says
317 which way). We take advantage of the fact that pointers are not allowed to
318 overflow by commuting arithmetic operations over conversions so that address
319 arithmetic insns can be used. */
322 convert_memory_address_addr_space (enum machine_mode to_mode ATTRIBUTE_UNUSED
,
323 rtx x
, addr_space_t as ATTRIBUTE_UNUSED
)
325 #ifndef POINTERS_EXTEND_UNSIGNED
326 gcc_assert (GET_MODE (x
) == to_mode
|| GET_MODE (x
) == VOIDmode
);
328 #else /* defined(POINTERS_EXTEND_UNSIGNED) */
329 enum machine_mode pointer_mode
, address_mode
, from_mode
;
333 /* If X already has the right mode, just return it. */
334 if (GET_MODE (x
) == to_mode
)
337 pointer_mode
= targetm
.addr_space
.pointer_mode (as
);
338 address_mode
= targetm
.addr_space
.address_mode (as
);
339 from_mode
= to_mode
== pointer_mode
? address_mode
: pointer_mode
;
341 /* Here we handle some special cases. If none of them apply, fall through
342 to the default case. */
343 switch (GET_CODE (x
))
347 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
))
349 else if (POINTERS_EXTEND_UNSIGNED
< 0)
351 else if (POINTERS_EXTEND_UNSIGNED
> 0)
355 temp
= simplify_unary_operation (code
, to_mode
, x
, from_mode
);
361 if ((SUBREG_PROMOTED_VAR_P (x
) || REG_POINTER (SUBREG_REG (x
)))
362 && GET_MODE (SUBREG_REG (x
)) == to_mode
)
363 return SUBREG_REG (x
);
367 temp
= gen_rtx_LABEL_REF (to_mode
, XEXP (x
, 0));
368 LABEL_REF_NONLOCAL_P (temp
) = LABEL_REF_NONLOCAL_P (x
);
373 temp
= shallow_copy_rtx (x
);
374 PUT_MODE (temp
, to_mode
);
379 return gen_rtx_CONST (to_mode
,
380 convert_memory_address_addr_space
381 (to_mode
, XEXP (x
, 0), as
));
386 /* For addition we can safely permute the conversion and addition
387 operation if one operand is a constant and converting the constant
388 does not change it or if one operand is a constant and we are
389 using a ptr_extend instruction (POINTERS_EXTEND_UNSIGNED < 0).
390 We can always safely permute them if we are making the address
392 if (GET_MODE_SIZE (to_mode
) < GET_MODE_SIZE (from_mode
)
393 || (GET_CODE (x
) == PLUS
394 && CONST_INT_P (XEXP (x
, 1))
395 && (XEXP (x
, 1) == convert_memory_address_addr_space
396 (to_mode
, XEXP (x
, 1), as
)
397 || POINTERS_EXTEND_UNSIGNED
< 0)))
398 return gen_rtx_fmt_ee (GET_CODE (x
), to_mode
,
399 convert_memory_address_addr_space
400 (to_mode
, XEXP (x
, 0), as
),
408 return convert_modes (to_mode
, from_mode
,
409 x
, POINTERS_EXTEND_UNSIGNED
);
410 #endif /* defined(POINTERS_EXTEND_UNSIGNED) */
413 /* Return something equivalent to X but valid as a memory address for something
414 of mode MODE in the named address space AS. When X is not itself valid,
415 this works by copying X or subexpressions of it into registers. */
418 memory_address_addr_space (enum machine_mode mode
, rtx x
, addr_space_t as
)
421 enum machine_mode address_mode
= targetm
.addr_space
.address_mode (as
);
423 x
= convert_memory_address_addr_space (address_mode
, x
, as
);
425 /* By passing constant addresses through registers
426 we get a chance to cse them. */
427 if (! cse_not_expected
&& CONSTANT_P (x
) && CONSTANT_ADDRESS_P (x
))
428 x
= force_reg (address_mode
, x
);
430 /* We get better cse by rejecting indirect addressing at this stage.
431 Let the combiner create indirect addresses where appropriate.
432 For now, generate the code so that the subexpressions useful to share
433 are visible. But not if cse won't be done! */
436 if (! cse_not_expected
&& !REG_P (x
))
437 x
= break_out_memory_refs (x
);
439 /* At this point, any valid address is accepted. */
440 if (memory_address_addr_space_p (mode
, x
, as
))
443 /* If it was valid before but breaking out memory refs invalidated it,
444 use it the old way. */
445 if (memory_address_addr_space_p (mode
, oldx
, as
))
451 /* Perform machine-dependent transformations on X
452 in certain cases. This is not necessary since the code
453 below can handle all possible cases, but machine-dependent
454 transformations can make better code. */
457 x
= targetm
.addr_space
.legitimize_address (x
, oldx
, mode
, as
);
458 if (orig_x
!= x
&& memory_address_addr_space_p (mode
, x
, as
))
462 /* PLUS and MULT can appear in special ways
463 as the result of attempts to make an address usable for indexing.
464 Usually they are dealt with by calling force_operand, below.
465 But a sum containing constant terms is special
466 if removing them makes the sum a valid address:
467 then we generate that address in a register
468 and index off of it. We do this because it often makes
469 shorter code, and because the addresses thus generated
470 in registers often become common subexpressions. */
471 if (GET_CODE (x
) == PLUS
)
473 rtx constant_term
= const0_rtx
;
474 rtx y
= eliminate_constant_term (x
, &constant_term
);
475 if (constant_term
== const0_rtx
476 || ! memory_address_addr_space_p (mode
, y
, as
))
477 x
= force_operand (x
, NULL_RTX
);
480 y
= gen_rtx_PLUS (GET_MODE (x
), copy_to_reg (y
), constant_term
);
481 if (! memory_address_addr_space_p (mode
, y
, as
))
482 x
= force_operand (x
, NULL_RTX
);
488 else if (GET_CODE (x
) == MULT
|| GET_CODE (x
) == MINUS
)
489 x
= force_operand (x
, NULL_RTX
);
491 /* If we have a register that's an invalid address,
492 it must be a hard reg of the wrong class. Copy it to a pseudo. */
496 /* Last resort: copy the value to a register, since
497 the register is a valid address. */
499 x
= force_reg (address_mode
, x
);
504 gcc_assert (memory_address_addr_space_p (mode
, x
, as
));
505 /* If we didn't change the address, we are done. Otherwise, mark
506 a reg as a pointer if we have REG or REG + CONST_INT. */
510 mark_reg_pointer (x
, BITS_PER_UNIT
);
511 else if (GET_CODE (x
) == PLUS
512 && REG_P (XEXP (x
, 0))
513 && CONST_INT_P (XEXP (x
, 1)))
514 mark_reg_pointer (XEXP (x
, 0), BITS_PER_UNIT
);
516 /* OLDX may have been the address on a temporary. Update the address
517 to indicate that X is now used. */
518 update_temp_slot_address (oldx
, x
);
523 /* Convert a mem ref into one with a valid memory address.
524 Pass through anything else unchanged. */
527 validize_mem (rtx ref
)
531 ref
= use_anchored_address (ref
);
532 if (memory_address_addr_space_p (GET_MODE (ref
), XEXP (ref
, 0),
533 MEM_ADDR_SPACE (ref
)))
536 /* Don't alter REF itself, since that is probably a stack slot. */
537 return replace_equiv_address (ref
, XEXP (ref
, 0));
540 /* If X is a memory reference to a member of an object block, try rewriting
541 it to use an anchor instead. Return the new memory reference on success
542 and the old one on failure. */
545 use_anchored_address (rtx x
)
548 HOST_WIDE_INT offset
;
550 if (!flag_section_anchors
)
556 /* Split the address into a base and offset. */
559 if (GET_CODE (base
) == CONST
560 && GET_CODE (XEXP (base
, 0)) == PLUS
561 && CONST_INT_P (XEXP (XEXP (base
, 0), 1)))
563 offset
+= INTVAL (XEXP (XEXP (base
, 0), 1));
564 base
= XEXP (XEXP (base
, 0), 0);
567 /* Check whether BASE is suitable for anchors. */
568 if (GET_CODE (base
) != SYMBOL_REF
569 || !SYMBOL_REF_HAS_BLOCK_INFO_P (base
)
570 || SYMBOL_REF_ANCHOR_P (base
)
571 || SYMBOL_REF_BLOCK (base
) == NULL
572 || !targetm
.use_anchors_for_symbol_p (base
))
575 /* Decide where BASE is going to be. */
576 place_block_symbol (base
);
578 /* Get the anchor we need to use. */
579 offset
+= SYMBOL_REF_BLOCK_OFFSET (base
);
580 base
= get_section_anchor (SYMBOL_REF_BLOCK (base
), offset
,
581 SYMBOL_REF_TLS_MODEL (base
));
583 /* Work out the offset from the anchor. */
584 offset
-= SYMBOL_REF_BLOCK_OFFSET (base
);
586 /* If we're going to run a CSE pass, force the anchor into a register.
587 We will then be able to reuse registers for several accesses, if the
588 target costs say that that's worthwhile. */
589 if (!cse_not_expected
)
590 base
= force_reg (GET_MODE (base
), base
);
592 return replace_equiv_address (x
, plus_constant (base
, offset
));
595 /* Copy the value or contents of X to a new temp reg and return that reg. */
600 rtx temp
= gen_reg_rtx (GET_MODE (x
));
602 /* If not an operand, must be an address with PLUS and MULT so
603 do the computation. */
604 if (! general_operand (x
, VOIDmode
))
605 x
= force_operand (x
, temp
);
608 emit_move_insn (temp
, x
);
613 /* Like copy_to_reg but always give the new register mode Pmode
614 in case X is a constant. */
617 copy_addr_to_reg (rtx x
)
619 return copy_to_mode_reg (Pmode
, x
);
622 /* Like copy_to_reg but always give the new register mode MODE
623 in case X is a constant. */
626 copy_to_mode_reg (enum machine_mode mode
, rtx x
)
628 rtx temp
= gen_reg_rtx (mode
);
630 /* If not an operand, must be an address with PLUS and MULT so
631 do the computation. */
632 if (! general_operand (x
, VOIDmode
))
633 x
= force_operand (x
, temp
);
635 gcc_assert (GET_MODE (x
) == mode
|| GET_MODE (x
) == VOIDmode
);
637 emit_move_insn (temp
, x
);
641 /* Load X into a register if it is not already one.
642 Use mode MODE for the register.
643 X should be valid for mode MODE, but it may be a constant which
644 is valid for all integer modes; that's why caller must specify MODE.
646 The caller must not alter the value in the register we return,
647 since we mark it as a "constant" register. */
650 force_reg (enum machine_mode mode
, rtx x
)
657 if (general_operand (x
, mode
))
659 temp
= gen_reg_rtx (mode
);
660 insn
= emit_move_insn (temp
, x
);
664 temp
= force_operand (x
, NULL_RTX
);
666 insn
= get_last_insn ();
669 rtx temp2
= gen_reg_rtx (mode
);
670 insn
= emit_move_insn (temp2
, temp
);
675 /* Let optimizers know that TEMP's value never changes
676 and that X can be substituted for it. Don't get confused
677 if INSN set something else (such as a SUBREG of TEMP). */
679 && (set
= single_set (insn
)) != 0
680 && SET_DEST (set
) == temp
681 && ! rtx_equal_p (x
, SET_SRC (set
)))
682 set_unique_reg_note (insn
, REG_EQUAL
, x
);
684 /* Let optimizers know that TEMP is a pointer, and if so, the
685 known alignment of that pointer. */
688 if (GET_CODE (x
) == SYMBOL_REF
)
690 align
= BITS_PER_UNIT
;
691 if (SYMBOL_REF_DECL (x
) && DECL_P (SYMBOL_REF_DECL (x
)))
692 align
= DECL_ALIGN (SYMBOL_REF_DECL (x
));
694 else if (GET_CODE (x
) == LABEL_REF
)
695 align
= BITS_PER_UNIT
;
696 else if (GET_CODE (x
) == CONST
697 && GET_CODE (XEXP (x
, 0)) == PLUS
698 && GET_CODE (XEXP (XEXP (x
, 0), 0)) == SYMBOL_REF
699 && CONST_INT_P (XEXP (XEXP (x
, 0), 1)))
701 rtx s
= XEXP (XEXP (x
, 0), 0);
702 rtx c
= XEXP (XEXP (x
, 0), 1);
706 if (SYMBOL_REF_DECL (s
) && DECL_P (SYMBOL_REF_DECL (s
)))
707 sa
= DECL_ALIGN (SYMBOL_REF_DECL (s
));
713 ca
= ctz_hwi (INTVAL (c
)) * BITS_PER_UNIT
;
714 align
= MIN (sa
, ca
);
718 if (align
|| (MEM_P (x
) && MEM_POINTER (x
)))
719 mark_reg_pointer (temp
, align
);
725 /* If X is a memory ref, copy its contents to a new temp reg and return
726 that reg. Otherwise, return X. */
729 force_not_mem (rtx x
)
733 if (!MEM_P (x
) || GET_MODE (x
) == BLKmode
)
736 temp
= gen_reg_rtx (GET_MODE (x
));
739 REG_POINTER (temp
) = 1;
741 emit_move_insn (temp
, x
);
745 /* Copy X to TARGET (if it's nonzero and a reg)
746 or to a new temp reg and return that reg.
747 MODE is the mode to use for X in case it is a constant. */
750 copy_to_suggested_reg (rtx x
, rtx target
, enum machine_mode mode
)
754 if (target
&& REG_P (target
))
757 temp
= gen_reg_rtx (mode
);
759 emit_move_insn (temp
, x
);
763 /* Return the mode to use to pass or return a scalar of TYPE and MODE.
764 PUNSIGNEDP points to the signedness of the type and may be adjusted
765 to show what signedness to use on extension operations.
767 FOR_RETURN is nonzero if the caller is promoting the return value
768 of FNDECL, else it is for promoting args. */
771 promote_function_mode (const_tree type
, enum machine_mode mode
, int *punsignedp
,
772 const_tree funtype
, int for_return
)
774 /* Called without a type node for a libcall. */
775 if (type
== NULL_TREE
)
777 if (INTEGRAL_MODE_P (mode
))
778 return targetm
.calls
.promote_function_mode (NULL_TREE
, mode
,
785 switch (TREE_CODE (type
))
787 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
788 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
789 case POINTER_TYPE
: case REFERENCE_TYPE
:
790 return targetm
.calls
.promote_function_mode (type
, mode
, punsignedp
, funtype
,
797 /* Return the mode to use to store a scalar of TYPE and MODE.
798 PUNSIGNEDP points to the signedness of the type and may be adjusted
799 to show what signedness to use on extension operations. */
802 promote_mode (const_tree type ATTRIBUTE_UNUSED
, enum machine_mode mode
,
803 int *punsignedp ATTRIBUTE_UNUSED
)
810 /* For libcalls this is invoked without TYPE from the backends
811 TARGET_PROMOTE_FUNCTION_MODE hooks. Don't do anything in that
813 if (type
== NULL_TREE
)
816 /* FIXME: this is the same logic that was there until GCC 4.4, but we
817 probably want to test POINTERS_EXTEND_UNSIGNED even if PROMOTE_MODE
818 is not defined. The affected targets are M32C, S390, SPARC. */
820 code
= TREE_CODE (type
);
821 unsignedp
= *punsignedp
;
825 case INTEGER_TYPE
: case ENUMERAL_TYPE
: case BOOLEAN_TYPE
:
826 case REAL_TYPE
: case OFFSET_TYPE
: case FIXED_POINT_TYPE
:
827 PROMOTE_MODE (mode
, unsignedp
, type
);
828 *punsignedp
= unsignedp
;
832 #ifdef POINTERS_EXTEND_UNSIGNED
835 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
836 return targetm
.addr_space
.address_mode
837 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
850 /* Use one of promote_mode or promote_function_mode to find the promoted
851 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
852 of DECL after promotion. */
855 promote_decl_mode (const_tree decl
, int *punsignedp
)
857 tree type
= TREE_TYPE (decl
);
858 int unsignedp
= TYPE_UNSIGNED (type
);
859 enum machine_mode mode
= DECL_MODE (decl
);
860 enum machine_mode pmode
;
862 if (TREE_CODE (decl
) == RESULT_DECL
863 || TREE_CODE (decl
) == PARM_DECL
)
864 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
865 TREE_TYPE (current_function_decl
), 2);
867 pmode
= promote_mode (type
, mode
, &unsignedp
);
870 *punsignedp
= unsignedp
;
875 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
876 This pops when ADJUST is positive. ADJUST need not be constant. */
879 adjust_stack (rtx adjust
)
883 if (adjust
== const0_rtx
)
886 /* We expect all variable sized adjustments to be multiple of
887 PREFERRED_STACK_BOUNDARY. */
888 if (CONST_INT_P (adjust
))
889 stack_pointer_delta
-= INTVAL (adjust
);
891 temp
= expand_binop (Pmode
,
892 #ifdef STACK_GROWS_DOWNWARD
897 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
900 if (temp
!= stack_pointer_rtx
)
901 emit_move_insn (stack_pointer_rtx
, temp
);
904 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
905 This pushes when ADJUST is positive. ADJUST need not be constant. */
908 anti_adjust_stack (rtx adjust
)
912 if (adjust
== const0_rtx
)
915 /* We expect all variable sized adjustments to be multiple of
916 PREFERRED_STACK_BOUNDARY. */
917 if (CONST_INT_P (adjust
))
918 stack_pointer_delta
+= INTVAL (adjust
);
920 temp
= expand_binop (Pmode
,
921 #ifdef STACK_GROWS_DOWNWARD
926 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
929 if (temp
!= stack_pointer_rtx
)
930 emit_move_insn (stack_pointer_rtx
, temp
);
933 /* Round the size of a block to be pushed up to the boundary required
934 by this machine. SIZE is the desired size, which need not be constant. */
937 round_push (rtx size
)
939 rtx align_rtx
, alignm1_rtx
;
941 if (!SUPPORTS_STACK_ALIGNMENT
942 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
944 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
949 if (CONST_INT_P (size
))
951 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
953 if (INTVAL (size
) != new_size
)
954 size
= GEN_INT (new_size
);
958 align_rtx
= GEN_INT (align
);
959 alignm1_rtx
= GEN_INT (align
- 1);
963 /* If crtl->preferred_stack_boundary might still grow, use
964 virtual_preferred_stack_boundary_rtx instead. This will be
965 substituted by the right value in vregs pass and optimized
967 align_rtx
= virtual_preferred_stack_boundary_rtx
;
968 alignm1_rtx
= force_operand (plus_constant (align_rtx
, -1), NULL_RTX
);
971 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
972 but we know it can't. So add ourselves and then do
974 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
975 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
976 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
978 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
983 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
984 to a previously-created save area. If no save area has been allocated,
985 this function will allocate one. If a save area is specified, it
986 must be of the proper mode. */
989 emit_stack_save (enum save_level save_level
, rtx
*psave
)
992 /* The default is that we use a move insn and save in a Pmode object. */
993 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
994 enum machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
996 /* See if this machine has anything special to do for this kind of save. */
999 #ifdef HAVE_save_stack_block
1001 if (HAVE_save_stack_block
)
1002 fcn
= gen_save_stack_block
;
1005 #ifdef HAVE_save_stack_function
1007 if (HAVE_save_stack_function
)
1008 fcn
= gen_save_stack_function
;
1011 #ifdef HAVE_save_stack_nonlocal
1013 if (HAVE_save_stack_nonlocal
)
1014 fcn
= gen_save_stack_nonlocal
;
1021 /* If there is no save area and we have to allocate one, do so. Otherwise
1022 verify the save area is the proper mode. */
1026 if (mode
!= VOIDmode
)
1028 if (save_level
== SAVE_NONLOCAL
)
1029 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1031 *psave
= sa
= gen_reg_rtx (mode
);
1035 do_pending_stack_adjust ();
1037 sa
= validize_mem (sa
);
1038 emit_insn (fcn (sa
, stack_pointer_rtx
));
1041 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1042 area made by emit_stack_save. If it is zero, we have nothing to do. */
1045 emit_stack_restore (enum save_level save_level
, rtx sa
)
1047 /* The default is that we use a move insn. */
1048 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
1050 /* See if this machine has anything special to do for this kind of save. */
1053 #ifdef HAVE_restore_stack_block
1055 if (HAVE_restore_stack_block
)
1056 fcn
= gen_restore_stack_block
;
1059 #ifdef HAVE_restore_stack_function
1061 if (HAVE_restore_stack_function
)
1062 fcn
= gen_restore_stack_function
;
1065 #ifdef HAVE_restore_stack_nonlocal
1067 if (HAVE_restore_stack_nonlocal
)
1068 fcn
= gen_restore_stack_nonlocal
;
1077 sa
= validize_mem (sa
);
1078 /* These clobbers prevent the scheduler from moving
1079 references to variable arrays below the code
1080 that deletes (pops) the arrays. */
1081 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1082 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1085 discard_pending_stack_adjust ();
1087 emit_insn (fcn (stack_pointer_rtx
, sa
));
1090 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1091 function. This function should be called whenever we allocate or
1092 deallocate dynamic stack space. */
1095 update_nonlocal_goto_save_area (void)
1100 /* The nonlocal_goto_save_area object is an array of N pointers. The
1101 first one is used for the frame pointer save; the rest are sized by
1102 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1103 of the stack save area slots. */
1104 t_save
= build4 (ARRAY_REF
, ptr_type_node
, cfun
->nonlocal_goto_save_area
,
1105 integer_one_node
, NULL_TREE
, NULL_TREE
);
1106 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1108 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1111 /* Return an rtx representing the address of an area of memory dynamically
1112 pushed on the stack.
1114 Any required stack pointer alignment is preserved.
1116 SIZE is an rtx representing the size of the area.
1118 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1119 parameter may be zero. If so, a proper value will be extracted
1120 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1122 REQUIRED_ALIGN is the alignment (in bits) required for the region
1125 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1126 stack space allocated by the generated code cannot be added with itself
1127 in the course of the execution of the function. It is always safe to
1128 pass FALSE here and the following criterion is sufficient in order to
1129 pass TRUE: every path in the CFG that starts at the allocation point and
1130 loops to it executes the associated deallocation code. */
1133 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1134 unsigned required_align
, bool cannot_accumulate
)
1136 HOST_WIDE_INT stack_usage_size
= -1;
1137 rtx final_label
, final_target
, target
;
1138 unsigned extra_align
= 0;
1141 /* If we're asking for zero bytes, it doesn't matter what we point
1142 to since we can't dereference it. But return a reasonable
1144 if (size
== const0_rtx
)
1145 return virtual_stack_dynamic_rtx
;
1147 /* Otherwise, show we're calling alloca or equivalent. */
1148 cfun
->calls_alloca
= 1;
1150 /* If stack usage info is requested, look into the size we are passed.
1151 We need to do so this early to avoid the obfuscation that may be
1152 introduced later by the various alignment operations. */
1153 if (flag_stack_usage_info
)
1155 if (CONST_INT_P (size
))
1156 stack_usage_size
= INTVAL (size
);
1157 else if (REG_P (size
))
1159 /* Look into the last emitted insn and see if we can deduce
1160 something for the register. */
1161 rtx insn
, set
, note
;
1162 insn
= get_last_insn ();
1163 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1165 if (CONST_INT_P (SET_SRC (set
)))
1166 stack_usage_size
= INTVAL (SET_SRC (set
));
1167 else if ((note
= find_reg_equal_equiv_note (insn
))
1168 && CONST_INT_P (XEXP (note
, 0)))
1169 stack_usage_size
= INTVAL (XEXP (note
, 0));
1173 /* If the size is not constant, we can't say anything. */
1174 if (stack_usage_size
== -1)
1176 current_function_has_unbounded_dynamic_stack_size
= 1;
1177 stack_usage_size
= 0;
1181 /* Ensure the size is in the proper mode. */
1182 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1183 size
= convert_to_mode (Pmode
, size
, 1);
1185 /* Adjust SIZE_ALIGN, if needed. */
1186 if (CONST_INT_P (size
))
1188 unsigned HOST_WIDE_INT lsb
;
1190 lsb
= INTVAL (size
);
1193 /* Watch out for overflow truncating to "unsigned". */
1194 if (lsb
> UINT_MAX
/ BITS_PER_UNIT
)
1195 size_align
= 1u << (HOST_BITS_PER_INT
- 1);
1197 size_align
= (unsigned)lsb
* BITS_PER_UNIT
;
1199 else if (size_align
< BITS_PER_UNIT
)
1200 size_align
= BITS_PER_UNIT
;
1202 /* We can't attempt to minimize alignment necessary, because we don't
1203 know the final value of preferred_stack_boundary yet while executing
1205 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1206 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1208 /* We will need to ensure that the address we return is aligned to
1209 REQUIRED_ALIGN. If STACK_DYNAMIC_OFFSET is defined, we don't
1210 always know its final value at this point in the compilation (it
1211 might depend on the size of the outgoing parameter lists, for
1212 example), so we must align the value to be returned in that case.
1213 (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
1214 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1215 We must also do an alignment operation on the returned value if
1216 the stack pointer alignment is less strict than REQUIRED_ALIGN.
1218 If we have to align, we must leave space in SIZE for the hole
1219 that might result from the alignment operation. */
1221 must_align
= (crtl
->preferred_stack_boundary
< required_align
);
1224 if (required_align
> PREFERRED_STACK_BOUNDARY
)
1225 extra_align
= PREFERRED_STACK_BOUNDARY
;
1226 else if (required_align
> STACK_BOUNDARY
)
1227 extra_align
= STACK_BOUNDARY
;
1229 extra_align
= BITS_PER_UNIT
;
1232 /* ??? STACK_POINTER_OFFSET is always defined now. */
1233 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
1235 extra_align
= BITS_PER_UNIT
;
1240 unsigned extra
= (required_align
- extra_align
) / BITS_PER_UNIT
;
1242 size
= plus_constant (size
, extra
);
1243 size
= force_operand (size
, NULL_RTX
);
1245 if (flag_stack_usage_info
)
1246 stack_usage_size
+= extra
;
1248 if (extra
&& size_align
> extra_align
)
1249 size_align
= extra_align
;
1252 /* Round the size to a multiple of the required stack alignment.
1253 Since the stack if presumed to be rounded before this allocation,
1254 this will maintain the required alignment.
1256 If the stack grows downward, we could save an insn by subtracting
1257 SIZE from the stack pointer and then aligning the stack pointer.
1258 The problem with this is that the stack pointer may be unaligned
1259 between the execution of the subtraction and alignment insns and
1260 some machines do not allow this. Even on those that do, some
1261 signal handlers malfunction if a signal should occur between those
1262 insns. Since this is an extremely rare event, we have no reliable
1263 way of knowing which systems have this problem. So we avoid even
1264 momentarily mis-aligning the stack. */
1265 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1267 size
= round_push (size
);
1269 if (flag_stack_usage_info
)
1271 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1272 stack_usage_size
= (stack_usage_size
+ align
- 1) / align
* align
;
1276 target
= gen_reg_rtx (Pmode
);
1278 /* The size is supposed to be fully adjusted at this point so record it
1279 if stack usage info is requested. */
1280 if (flag_stack_usage_info
)
1282 current_function_dynamic_stack_size
+= stack_usage_size
;
1284 /* ??? This is gross but the only safe stance in the absence
1285 of stack usage oriented flow analysis. */
1286 if (!cannot_accumulate
)
1287 current_function_has_unbounded_dynamic_stack_size
= 1;
1290 final_label
= NULL_RTX
;
1291 final_target
= NULL_RTX
;
1293 /* If we are splitting the stack, we need to ask the backend whether
1294 there is enough room on the current stack. If there isn't, or if
1295 the backend doesn't know how to tell is, then we need to call a
1296 function to allocate memory in some other way. This memory will
1297 be released when we release the current stack segment. The
1298 effect is that stack allocation becomes less efficient, but at
1299 least it doesn't cause a stack overflow. */
1300 if (flag_split_stack
)
1302 rtx available_label
, ask
, space
, func
;
1304 available_label
= NULL_RTX
;
1306 #ifdef HAVE_split_stack_space_check
1307 if (HAVE_split_stack_space_check
)
1309 available_label
= gen_label_rtx ();
1311 /* This instruction will branch to AVAILABLE_LABEL if there
1312 are SIZE bytes available on the stack. */
1313 emit_insn (gen_split_stack_space_check (size
, available_label
));
1317 /* The __morestack_allocate_stack_space function will allocate
1318 memory using malloc. If the alignment of the memory returned
1319 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1320 make sure we allocate enough space. */
1321 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1325 ask
= expand_binop (Pmode
, add_optab
, size
,
1326 GEN_INT (required_align
/ BITS_PER_UNIT
- 1),
1327 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1331 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1333 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1336 if (available_label
== NULL_RTX
)
1339 final_target
= gen_reg_rtx (Pmode
);
1341 emit_move_insn (final_target
, space
);
1343 final_label
= gen_label_rtx ();
1344 emit_jump (final_label
);
1346 emit_label (available_label
);
1349 do_pending_stack_adjust ();
1351 /* We ought to be called always on the toplevel and stack ought to be aligned
1353 gcc_assert (!(stack_pointer_delta
1354 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1356 /* If needed, check that we have the required amount of stack. Take into
1357 account what has already been checked. */
1358 if (STACK_CHECK_MOVING_SP
)
1360 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1361 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1363 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1364 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1366 /* Perform the required allocation from the stack. Some systems do
1367 this differently than simply incrementing/decrementing from the
1368 stack pointer, such as acquiring the space by calling malloc(). */
1369 #ifdef HAVE_allocate_stack
1370 if (HAVE_allocate_stack
)
1372 struct expand_operand ops
[2];
1373 /* We don't have to check against the predicate for operand 0 since
1374 TARGET is known to be a pseudo of the proper mode, which must
1375 be valid for the operand. */
1376 create_fixed_operand (&ops
[0], target
);
1377 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1378 expand_insn (CODE_FOR_allocate_stack
, 2, ops
);
1383 int saved_stack_pointer_delta
;
1385 #ifndef STACK_GROWS_DOWNWARD
1386 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1389 /* Check stack bounds if necessary. */
1390 if (crtl
->limit_stack
)
1393 rtx space_available
= gen_label_rtx ();
1394 #ifdef STACK_GROWS_DOWNWARD
1395 available
= expand_binop (Pmode
, sub_optab
,
1396 stack_pointer_rtx
, stack_limit_rtx
,
1397 NULL_RTX
, 1, OPTAB_WIDEN
);
1399 available
= expand_binop (Pmode
, sub_optab
,
1400 stack_limit_rtx
, stack_pointer_rtx
,
1401 NULL_RTX
, 1, OPTAB_WIDEN
);
1403 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1407 emit_insn (gen_trap ());
1410 error ("stack limits not supported on this target");
1412 emit_label (space_available
);
1415 saved_stack_pointer_delta
= stack_pointer_delta
;
1416 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1417 anti_adjust_stack_and_probe (size
, false);
1419 anti_adjust_stack (size
);
1420 /* Even if size is constant, don't modify stack_pointer_delta.
1421 The constant size alloca should preserve
1422 crtl->preferred_stack_boundary alignment. */
1423 stack_pointer_delta
= saved_stack_pointer_delta
;
1425 #ifdef STACK_GROWS_DOWNWARD
1426 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1430 /* Finish up the split stack handling. */
1431 if (final_label
!= NULL_RTX
)
1433 gcc_assert (flag_split_stack
);
1434 emit_move_insn (final_target
, target
);
1435 emit_label (final_label
);
1436 target
= final_target
;
1441 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1442 but we know it can't. So add ourselves and then do
1444 target
= expand_binop (Pmode
, add_optab
, target
,
1445 GEN_INT (required_align
/ BITS_PER_UNIT
- 1),
1446 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1447 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1448 GEN_INT (required_align
/ BITS_PER_UNIT
),
1450 target
= expand_mult (Pmode
, target
,
1451 GEN_INT (required_align
/ BITS_PER_UNIT
),
1455 /* Now that we've committed to a return value, mark its alignment. */
1456 mark_reg_pointer (target
, required_align
);
1458 /* Record the new stack level for nonlocal gotos. */
1459 if (cfun
->nonlocal_goto_save_area
!= 0)
1460 update_nonlocal_goto_save_area ();
1465 /* A front end may want to override GCC's stack checking by providing a
1466 run-time routine to call to check the stack, so provide a mechanism for
1467 calling that routine. */
1469 static GTY(()) rtx stack_check_libfunc
;
1472 set_stack_check_libfunc (const char *libfunc_name
)
1474 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1475 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1478 /* Emit one stack probe at ADDRESS, an address within the stack. */
1481 emit_stack_probe (rtx address
)
1483 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1485 MEM_VOLATILE_P (memref
) = 1;
1487 /* See if we have an insn to probe the stack. */
1488 #ifdef HAVE_probe_stack
1489 if (HAVE_probe_stack
)
1490 emit_insn (gen_probe_stack (memref
));
1493 emit_move_insn (memref
, const0_rtx
);
1496 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1497 FIRST is a constant and size is a Pmode RTX. These are offsets from
1498 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1499 or subtract them from the stack pointer. */
1501 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1503 #ifdef STACK_GROWS_DOWNWARD
1504 #define STACK_GROW_OP MINUS
1505 #define STACK_GROW_OPTAB sub_optab
1506 #define STACK_GROW_OFF(off) -(off)
1508 #define STACK_GROW_OP PLUS
1509 #define STACK_GROW_OPTAB add_optab
1510 #define STACK_GROW_OFF(off) (off)
1514 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1516 /* First ensure SIZE is Pmode. */
1517 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1518 size
= convert_to_mode (Pmode
, size
, 1);
1520 /* Next see if we have a function to check the stack. */
1521 if (stack_check_libfunc
)
1523 rtx addr
= memory_address (Pmode
,
1524 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1526 plus_constant (size
, first
)));
1527 emit_library_call (stack_check_libfunc
, LCT_NORMAL
, VOIDmode
, 1, addr
,
1532 /* Next see if we have an insn to check the stack. */
1533 #ifdef HAVE_check_stack
1534 if (HAVE_check_stack
)
1536 struct expand_operand ops
[1];
1537 rtx addr
= memory_address (Pmode
,
1538 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1540 plus_constant (size
, first
)));
1542 create_input_operand (&ops
[0], addr
, Pmode
);
1543 if (maybe_expand_insn (CODE_FOR_check_stack
, 1, ops
))
1548 /* Otherwise we have to generate explicit probes. If we have a constant
1549 small number of them to generate, that's the easy case. */
1550 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1552 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1555 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1556 it exceeds SIZE. If only one probe is needed, this will not
1557 generate any code. Then probe at FIRST + SIZE. */
1558 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1560 addr
= memory_address (Pmode
,
1561 plus_constant (stack_pointer_rtx
,
1562 STACK_GROW_OFF (first
+ i
)));
1563 emit_stack_probe (addr
);
1566 addr
= memory_address (Pmode
,
1567 plus_constant (stack_pointer_rtx
,
1568 STACK_GROW_OFF (first
+ isize
)));
1569 emit_stack_probe (addr
);
1572 /* In the variable case, do the same as above, but in a loop. Note that we
1573 must be extra careful with variables wrapping around because we might be
1574 at the very top (or the very bottom) of the address space and we have to
1575 be able to handle this case properly; in particular, we use an equality
1576 test for the loop condition. */
1579 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1580 rtx loop_lab
= gen_label_rtx ();
1581 rtx end_lab
= gen_label_rtx ();
1584 /* Step 1: round SIZE to the previous multiple of the interval. */
1586 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1588 = simplify_gen_binary (AND
, Pmode
, size
, GEN_INT (-PROBE_INTERVAL
));
1589 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1592 /* Step 2: compute initial and final value of the loop counter. */
1594 /* TEST_ADDR = SP + FIRST. */
1595 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1597 GEN_INT (first
)), NULL_RTX
);
1599 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1600 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1602 rounded_size_op
), NULL_RTX
);
1607 while (TEST_ADDR != LAST_ADDR)
1609 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1613 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1614 until it is equal to ROUNDED_SIZE. */
1616 emit_label (loop_lab
);
1618 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1619 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1622 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1623 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1624 GEN_INT (PROBE_INTERVAL
), test_addr
,
1627 gcc_assert (temp
== test_addr
);
1629 /* Probe at TEST_ADDR. */
1630 emit_stack_probe (test_addr
);
1632 emit_jump (loop_lab
);
1634 emit_label (end_lab
);
1637 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1638 that SIZE is equal to ROUNDED_SIZE. */
1640 /* TEMP = SIZE - ROUNDED_SIZE. */
1641 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1642 if (temp
!= const0_rtx
)
1646 if (CONST_INT_P (temp
))
1648 /* Use [base + disp} addressing mode if supported. */
1649 HOST_WIDE_INT offset
= INTVAL (temp
);
1650 addr
= memory_address (Pmode
,
1651 plus_constant (last_addr
,
1652 STACK_GROW_OFF (offset
)));
1656 /* Manual CSE if the difference is not known at compile-time. */
1657 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1658 addr
= memory_address (Pmode
,
1659 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1663 emit_stack_probe (addr
);
1668 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1669 while probing it. This pushes when SIZE is positive. SIZE need not
1670 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1671 by plus SIZE at the end. */
1674 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1676 /* We skip the probe for the first interval + a small dope of 4 words and
1677 probe that many bytes past the specified size to maintain a protection
1678 area at the botton of the stack. */
1679 const int dope
= 4 * UNITS_PER_WORD
;
1681 /* First ensure SIZE is Pmode. */
1682 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1683 size
= convert_to_mode (Pmode
, size
, 1);
1685 /* If we have a constant small number of probes to generate, that's the
1687 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1689 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1690 bool first_probe
= true;
1692 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1693 values of N from 1 until it exceeds SIZE. If only one probe is
1694 needed, this will not generate any code. Then adjust and probe
1695 to PROBE_INTERVAL + SIZE. */
1696 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1700 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1701 first_probe
= false;
1704 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1705 emit_stack_probe (stack_pointer_rtx
);
1709 anti_adjust_stack (plus_constant (size
, PROBE_INTERVAL
+ dope
));
1711 anti_adjust_stack (plus_constant (size
, PROBE_INTERVAL
- i
));
1712 emit_stack_probe (stack_pointer_rtx
);
1715 /* In the variable case, do the same as above, but in a loop. Note that we
1716 must be extra careful with variables wrapping around because we might be
1717 at the very top (or the very bottom) of the address space and we have to
1718 be able to handle this case properly; in particular, we use an equality
1719 test for the loop condition. */
1722 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1723 rtx loop_lab
= gen_label_rtx ();
1724 rtx end_lab
= gen_label_rtx ();
1727 /* Step 1: round SIZE to the previous multiple of the interval. */
1729 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1731 = simplify_gen_binary (AND
, Pmode
, size
, GEN_INT (-PROBE_INTERVAL
));
1732 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1735 /* Step 2: compute initial and final value of the loop counter. */
1737 /* SP = SP_0 + PROBE_INTERVAL. */
1738 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1740 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1741 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1743 rounded_size_op
), NULL_RTX
);
1748 while (SP != LAST_ADDR)
1750 SP = SP + PROBE_INTERVAL
1754 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1755 values of N from 1 until it is equal to ROUNDED_SIZE. */
1757 emit_label (loop_lab
);
1759 /* Jump to END_LAB if SP == LAST_ADDR. */
1760 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1763 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1764 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1765 emit_stack_probe (stack_pointer_rtx
);
1767 emit_jump (loop_lab
);
1769 emit_label (end_lab
);
1772 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1773 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1775 /* TEMP = SIZE - ROUNDED_SIZE. */
1776 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1777 if (temp
!= const0_rtx
)
1779 /* Manual CSE if the difference is not known at compile-time. */
1780 if (GET_CODE (temp
) != CONST_INT
)
1781 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1782 anti_adjust_stack (temp
);
1783 emit_stack_probe (stack_pointer_rtx
);
1787 /* Adjust back and account for the additional first interval. */
1789 adjust_stack (plus_constant (size
, PROBE_INTERVAL
+ dope
));
1791 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1794 /* Return an rtx representing the register or memory location
1795 in which a scalar value of data type VALTYPE
1796 was returned by a function call to function FUNC.
1797 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1798 function is known, otherwise 0.
1799 OUTGOING is 1 if on a machine with register windows this function
1800 should return the register in which the function will put its result
1804 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1805 int outgoing ATTRIBUTE_UNUSED
)
1809 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1812 && GET_MODE (val
) == BLKmode
)
1814 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1815 enum machine_mode tmpmode
;
1817 /* int_size_in_bytes can return -1. We don't need a check here
1818 since the value of bytes will then be large enough that no
1819 mode will match anyway. */
1821 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1822 tmpmode
!= VOIDmode
;
1823 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1825 /* Have we found a large enough mode? */
1826 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1830 /* No suitable mode found. */
1831 gcc_assert (tmpmode
!= VOIDmode
);
1833 PUT_MODE (val
, tmpmode
);
1838 /* Return an rtx representing the register or memory location
1839 in which a scalar value of mode MODE was returned by a library call. */
1842 hard_libcall_value (enum machine_mode mode
, rtx fun
)
1844 return targetm
.calls
.libcall_value (mode
, fun
);
1847 /* Look up the tree code for a given rtx code
1848 to provide the arithmetic operation for REAL_ARITHMETIC.
1849 The function returns an int because the caller may not know
1850 what `enum tree_code' means. */
1853 rtx_to_tree_code (enum rtx_code code
)
1855 enum tree_code tcode
;
1878 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1881 return ((int) tcode
);
1884 #include "gt-explow.h"