1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987, 1991, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
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 if (upc_shared_type_p (TREE_TYPE (type
)))
837 *punsignedp
= POINTERS_EXTEND_UNSIGNED
;
838 return targetm
.addr_space
.address_mode
839 (TYPE_ADDR_SPACE (TREE_TYPE (type
)));
852 /* Use one of promote_mode or promote_function_mode to find the promoted
853 mode of DECL. If PUNSIGNEDP is not NULL, store there the unsignedness
854 of DECL after promotion. */
857 promote_decl_mode (const_tree decl
, int *punsignedp
)
859 tree type
= TREE_TYPE (decl
);
860 int unsignedp
= TYPE_UNSIGNED (type
);
861 enum machine_mode mode
= DECL_MODE (decl
);
862 enum machine_mode pmode
;
864 if (TREE_CODE (decl
) == RESULT_DECL
865 || TREE_CODE (decl
) == PARM_DECL
)
866 pmode
= promote_function_mode (type
, mode
, &unsignedp
,
867 TREE_TYPE (current_function_decl
), 2);
869 pmode
= promote_mode (type
, mode
, &unsignedp
);
872 *punsignedp
= unsignedp
;
877 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
878 This pops when ADJUST is positive. ADJUST need not be constant. */
881 adjust_stack (rtx adjust
)
885 if (adjust
== const0_rtx
)
888 /* We expect all variable sized adjustments to be multiple of
889 PREFERRED_STACK_BOUNDARY. */
890 if (CONST_INT_P (adjust
))
891 stack_pointer_delta
-= INTVAL (adjust
);
893 temp
= expand_binop (Pmode
,
894 #ifdef STACK_GROWS_DOWNWARD
899 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
902 if (temp
!= stack_pointer_rtx
)
903 emit_move_insn (stack_pointer_rtx
, temp
);
906 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
907 This pushes when ADJUST is positive. ADJUST need not be constant. */
910 anti_adjust_stack (rtx adjust
)
914 if (adjust
== const0_rtx
)
917 /* We expect all variable sized adjustments to be multiple of
918 PREFERRED_STACK_BOUNDARY. */
919 if (CONST_INT_P (adjust
))
920 stack_pointer_delta
+= INTVAL (adjust
);
922 temp
= expand_binop (Pmode
,
923 #ifdef STACK_GROWS_DOWNWARD
928 stack_pointer_rtx
, adjust
, stack_pointer_rtx
, 0,
931 if (temp
!= stack_pointer_rtx
)
932 emit_move_insn (stack_pointer_rtx
, temp
);
935 /* Round the size of a block to be pushed up to the boundary required
936 by this machine. SIZE is the desired size, which need not be constant. */
939 round_push (rtx size
)
941 rtx align_rtx
, alignm1_rtx
;
943 if (!SUPPORTS_STACK_ALIGNMENT
944 || crtl
->preferred_stack_boundary
== MAX_SUPPORTED_STACK_ALIGNMENT
)
946 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
951 if (CONST_INT_P (size
))
953 HOST_WIDE_INT new_size
= (INTVAL (size
) + align
- 1) / align
* align
;
955 if (INTVAL (size
) != new_size
)
956 size
= GEN_INT (new_size
);
960 align_rtx
= GEN_INT (align
);
961 alignm1_rtx
= GEN_INT (align
- 1);
965 /* If crtl->preferred_stack_boundary might still grow, use
966 virtual_preferred_stack_boundary_rtx instead. This will be
967 substituted by the right value in vregs pass and optimized
969 align_rtx
= virtual_preferred_stack_boundary_rtx
;
970 alignm1_rtx
= force_operand (plus_constant (align_rtx
, -1), NULL_RTX
);
973 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
974 but we know it can't. So add ourselves and then do
976 size
= expand_binop (Pmode
, add_optab
, size
, alignm1_rtx
,
977 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
978 size
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, size
, align_rtx
,
980 size
= expand_mult (Pmode
, size
, align_rtx
, NULL_RTX
, 1);
985 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
986 to a previously-created save area. If no save area has been allocated,
987 this function will allocate one. If a save area is specified, it
988 must be of the proper mode. */
991 emit_stack_save (enum save_level save_level
, rtx
*psave
)
994 /* The default is that we use a move insn and save in a Pmode object. */
995 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
996 enum machine_mode mode
= STACK_SAVEAREA_MODE (save_level
);
998 /* See if this machine has anything special to do for this kind of save. */
1001 #ifdef HAVE_save_stack_block
1003 if (HAVE_save_stack_block
)
1004 fcn
= gen_save_stack_block
;
1007 #ifdef HAVE_save_stack_function
1009 if (HAVE_save_stack_function
)
1010 fcn
= gen_save_stack_function
;
1013 #ifdef HAVE_save_stack_nonlocal
1015 if (HAVE_save_stack_nonlocal
)
1016 fcn
= gen_save_stack_nonlocal
;
1023 /* If there is no save area and we have to allocate one, do so. Otherwise
1024 verify the save area is the proper mode. */
1028 if (mode
!= VOIDmode
)
1030 if (save_level
== SAVE_NONLOCAL
)
1031 *psave
= sa
= assign_stack_local (mode
, GET_MODE_SIZE (mode
), 0);
1033 *psave
= sa
= gen_reg_rtx (mode
);
1037 do_pending_stack_adjust ();
1039 sa
= validize_mem (sa
);
1040 emit_insn (fcn (sa
, stack_pointer_rtx
));
1043 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1044 area made by emit_stack_save. If it is zero, we have nothing to do. */
1047 emit_stack_restore (enum save_level save_level
, rtx sa
)
1049 /* The default is that we use a move insn. */
1050 rtx (*fcn
) (rtx
, rtx
) = gen_move_insn
;
1052 /* See if this machine has anything special to do for this kind of save. */
1055 #ifdef HAVE_restore_stack_block
1057 if (HAVE_restore_stack_block
)
1058 fcn
= gen_restore_stack_block
;
1061 #ifdef HAVE_restore_stack_function
1063 if (HAVE_restore_stack_function
)
1064 fcn
= gen_restore_stack_function
;
1067 #ifdef HAVE_restore_stack_nonlocal
1069 if (HAVE_restore_stack_nonlocal
)
1070 fcn
= gen_restore_stack_nonlocal
;
1079 sa
= validize_mem (sa
);
1080 /* These clobbers prevent the scheduler from moving
1081 references to variable arrays below the code
1082 that deletes (pops) the arrays. */
1083 emit_clobber (gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
)));
1084 emit_clobber (gen_rtx_MEM (BLKmode
, stack_pointer_rtx
));
1087 discard_pending_stack_adjust ();
1089 emit_insn (fcn (stack_pointer_rtx
, sa
));
1092 /* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
1093 function. This function should be called whenever we allocate or
1094 deallocate dynamic stack space. */
1097 update_nonlocal_goto_save_area (void)
1102 /* The nonlocal_goto_save_area object is an array of N pointers. The
1103 first one is used for the frame pointer save; the rest are sized by
1104 STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
1105 of the stack save area slots. */
1106 t_save
= build4 (ARRAY_REF
, ptr_type_node
, cfun
->nonlocal_goto_save_area
,
1107 integer_one_node
, NULL_TREE
, NULL_TREE
);
1108 r_save
= expand_expr (t_save
, NULL_RTX
, VOIDmode
, EXPAND_WRITE
);
1110 emit_stack_save (SAVE_NONLOCAL
, &r_save
);
1113 /* Return an rtx representing the address of an area of memory dynamically
1114 pushed on the stack.
1116 Any required stack pointer alignment is preserved.
1118 SIZE is an rtx representing the size of the area.
1120 SIZE_ALIGN is the alignment (in bits) that we know SIZE has. This
1121 parameter may be zero. If so, a proper value will be extracted
1122 from SIZE if it is constant, otherwise BITS_PER_UNIT will be assumed.
1124 REQUIRED_ALIGN is the alignment (in bits) required for the region
1127 If CANNOT_ACCUMULATE is set to TRUE, the caller guarantees that the
1128 stack space allocated by the generated code cannot be added with itself
1129 in the course of the execution of the function. It is always safe to
1130 pass FALSE here and the following criterion is sufficient in order to
1131 pass TRUE: every path in the CFG that starts at the allocation point and
1132 loops to it executes the associated deallocation code. */
1135 allocate_dynamic_stack_space (rtx size
, unsigned size_align
,
1136 unsigned required_align
, bool cannot_accumulate
)
1138 HOST_WIDE_INT stack_usage_size
= -1;
1139 rtx final_label
, final_target
, target
;
1140 unsigned extra_align
= 0;
1143 /* If we're asking for zero bytes, it doesn't matter what we point
1144 to since we can't dereference it. But return a reasonable
1146 if (size
== const0_rtx
)
1147 return virtual_stack_dynamic_rtx
;
1149 /* Otherwise, show we're calling alloca or equivalent. */
1150 cfun
->calls_alloca
= 1;
1152 /* If stack usage info is requested, look into the size we are passed.
1153 We need to do so this early to avoid the obfuscation that may be
1154 introduced later by the various alignment operations. */
1155 if (flag_stack_usage
)
1157 if (CONST_INT_P (size
))
1158 stack_usage_size
= INTVAL (size
);
1159 else if (REG_P (size
))
1161 /* Look into the last emitted insn and see if we can deduce
1162 something for the register. */
1163 rtx insn
, set
, note
;
1164 insn
= get_last_insn ();
1165 if ((set
= single_set (insn
)) && rtx_equal_p (SET_DEST (set
), size
))
1167 if (CONST_INT_P (SET_SRC (set
)))
1168 stack_usage_size
= INTVAL (SET_SRC (set
));
1169 else if ((note
= find_reg_equal_equiv_note (insn
))
1170 && CONST_INT_P (XEXP (note
, 0)))
1171 stack_usage_size
= INTVAL (XEXP (note
, 0));
1175 /* If the size is not constant, we can't say anything. */
1176 if (stack_usage_size
== -1)
1178 current_function_has_unbounded_dynamic_stack_size
= 1;
1179 stack_usage_size
= 0;
1183 /* Ensure the size is in the proper mode. */
1184 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1185 size
= convert_to_mode (Pmode
, size
, 1);
1187 /* Adjust SIZE_ALIGN, if needed. */
1188 if (CONST_INT_P (size
))
1190 unsigned HOST_WIDE_INT lsb
;
1192 lsb
= INTVAL (size
);
1195 /* Watch out for overflow truncating to "unsigned". */
1196 if (lsb
> UINT_MAX
/ BITS_PER_UNIT
)
1197 size_align
= 1u << (HOST_BITS_PER_INT
- 1);
1199 size_align
= (unsigned)lsb
* BITS_PER_UNIT
;
1201 else if (size_align
< BITS_PER_UNIT
)
1202 size_align
= BITS_PER_UNIT
;
1204 /* We can't attempt to minimize alignment necessary, because we don't
1205 know the final value of preferred_stack_boundary yet while executing
1207 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
1208 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
1210 /* We will need to ensure that the address we return is aligned to
1211 REQUIRED_ALIGN. If STACK_DYNAMIC_OFFSET is defined, we don't
1212 always know its final value at this point in the compilation (it
1213 might depend on the size of the outgoing parameter lists, for
1214 example), so we must align the value to be returned in that case.
1215 (Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
1216 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1217 We must also do an alignment operation on the returned value if
1218 the stack pointer alignment is less strict than REQUIRED_ALIGN.
1220 If we have to align, we must leave space in SIZE for the hole
1221 that might result from the alignment operation. */
1223 must_align
= (crtl
->preferred_stack_boundary
< required_align
);
1226 if (required_align
> PREFERRED_STACK_BOUNDARY
)
1227 extra_align
= PREFERRED_STACK_BOUNDARY
;
1228 else if (required_align
> STACK_BOUNDARY
)
1229 extra_align
= STACK_BOUNDARY
;
1231 extra_align
= BITS_PER_UNIT
;
1234 /* ??? STACK_POINTER_OFFSET is always defined now. */
1235 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
1237 extra_align
= BITS_PER_UNIT
;
1242 unsigned extra
= (required_align
- extra_align
) / BITS_PER_UNIT
;
1244 size
= plus_constant (size
, extra
);
1245 size
= force_operand (size
, NULL_RTX
);
1247 if (flag_stack_usage
)
1248 stack_usage_size
+= extra
;
1250 if (extra
&& size_align
> extra_align
)
1251 size_align
= extra_align
;
1254 #ifdef SETJMP_VIA_SAVE_AREA
1255 /* If setjmp restores regs from a save area in the stack frame,
1256 avoid clobbering the reg save area. Note that the offset of
1257 virtual_incoming_args_rtx includes the preallocated stack args space.
1258 It would be no problem to clobber that, but it's on the wrong side
1259 of the old save area.
1261 What used to happen is that, since we did not know for sure
1262 whether setjmp() was invoked until after RTL generation, we
1263 would use reg notes to store the "optimized" size and fix things
1264 up later. These days we know this information before we ever
1265 start building RTL so the reg notes are unnecessary. */
1266 if (cfun
->calls_setjmp
)
1269 = expand_binop (Pmode
, sub_optab
, virtual_stack_dynamic_rtx
,
1270 stack_pointer_rtx
, NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1272 size
= expand_binop (Pmode
, add_optab
, size
, dynamic_offset
,
1273 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1275 /* The above dynamic offset cannot be computed statically at this
1276 point, but it will be possible to do so after RTL expansion is
1277 done. Record how many times we will need to add it. */
1278 if (flag_stack_usage
)
1279 current_function_dynamic_alloc_count
++;
1281 /* ??? Can we infer a minimum of STACK_BOUNDARY here? */
1282 size_align
= BITS_PER_UNIT
;
1284 #endif /* SETJMP_VIA_SAVE_AREA */
1286 /* Round the size to a multiple of the required stack alignment.
1287 Since the stack if presumed to be rounded before this allocation,
1288 this will maintain the required alignment.
1290 If the stack grows downward, we could save an insn by subtracting
1291 SIZE from the stack pointer and then aligning the stack pointer.
1292 The problem with this is that the stack pointer may be unaligned
1293 between the execution of the subtraction and alignment insns and
1294 some machines do not allow this. Even on those that do, some
1295 signal handlers malfunction if a signal should occur between those
1296 insns. Since this is an extremely rare event, we have no reliable
1297 way of knowing which systems have this problem. So we avoid even
1298 momentarily mis-aligning the stack. */
1299 if (size_align
% MAX_SUPPORTED_STACK_ALIGNMENT
!= 0)
1301 size
= round_push (size
);
1303 if (flag_stack_usage
)
1305 int align
= crtl
->preferred_stack_boundary
/ BITS_PER_UNIT
;
1306 stack_usage_size
= (stack_usage_size
+ align
- 1) / align
* align
;
1310 target
= gen_reg_rtx (Pmode
);
1312 /* The size is supposed to be fully adjusted at this point so record it
1313 if stack usage info is requested. */
1314 if (flag_stack_usage
)
1316 current_function_dynamic_stack_size
+= stack_usage_size
;
1318 /* ??? This is gross but the only safe stance in the absence
1319 of stack usage oriented flow analysis. */
1320 if (!cannot_accumulate
)
1321 current_function_has_unbounded_dynamic_stack_size
= 1;
1324 final_label
= NULL_RTX
;
1325 final_target
= NULL_RTX
;
1327 /* If we are splitting the stack, we need to ask the backend whether
1328 there is enough room on the current stack. If there isn't, or if
1329 the backend doesn't know how to tell is, then we need to call a
1330 function to allocate memory in some other way. This memory will
1331 be released when we release the current stack segment. The
1332 effect is that stack allocation becomes less efficient, but at
1333 least it doesn't cause a stack overflow. */
1334 if (flag_split_stack
)
1336 rtx available_label
, ask
, space
, func
;
1338 available_label
= NULL_RTX
;
1340 #ifdef HAVE_split_stack_space_check
1341 if (HAVE_split_stack_space_check
)
1343 available_label
= gen_label_rtx ();
1345 /* This instruction will branch to AVAILABLE_LABEL if there
1346 are SIZE bytes available on the stack. */
1347 emit_insn (gen_split_stack_space_check (size
, available_label
));
1351 /* The __morestack_allocate_stack_space function will allocate
1352 memory using malloc. If the alignment of the memory returned
1353 by malloc does not meet REQUIRED_ALIGN, we increase SIZE to
1354 make sure we allocate enough space. */
1355 if (MALLOC_ABI_ALIGNMENT
>= required_align
)
1359 ask
= expand_binop (Pmode
, add_optab
, size
,
1360 GEN_INT (required_align
/ BITS_PER_UNIT
- 1),
1361 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1365 func
= init_one_libfunc ("__morestack_allocate_stack_space");
1367 space
= emit_library_call_value (func
, target
, LCT_NORMAL
, Pmode
,
1370 if (available_label
== NULL_RTX
)
1373 final_target
= gen_reg_rtx (Pmode
);
1375 emit_move_insn (final_target
, space
);
1377 final_label
= gen_label_rtx ();
1378 emit_jump (final_label
);
1380 emit_label (available_label
);
1383 do_pending_stack_adjust ();
1385 /* We ought to be called always on the toplevel and stack ought to be aligned
1387 gcc_assert (!(stack_pointer_delta
1388 % (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
)));
1390 /* If needed, check that we have the required amount of stack. Take into
1391 account what has already been checked. */
1392 if (STACK_CHECK_MOVING_SP
)
1394 else if (flag_stack_check
== GENERIC_STACK_CHECK
)
1395 probe_stack_range (STACK_OLD_CHECK_PROTECT
+ STACK_CHECK_MAX_FRAME_SIZE
,
1397 else if (flag_stack_check
== STATIC_BUILTIN_STACK_CHECK
)
1398 probe_stack_range (STACK_CHECK_PROTECT
, size
);
1400 /* Perform the required allocation from the stack. Some systems do
1401 this differently than simply incrementing/decrementing from the
1402 stack pointer, such as acquiring the space by calling malloc(). */
1403 #ifdef HAVE_allocate_stack
1404 if (HAVE_allocate_stack
)
1406 struct expand_operand ops
[2];
1407 /* We don't have to check against the predicate for operand 0 since
1408 TARGET is known to be a pseudo of the proper mode, which must
1409 be valid for the operand. */
1410 create_fixed_operand (&ops
[0], target
);
1411 create_convert_operand_to (&ops
[1], size
, STACK_SIZE_MODE
, true);
1412 expand_insn (CODE_FOR_allocate_stack
, 2, ops
);
1417 int saved_stack_pointer_delta
;
1419 #ifndef STACK_GROWS_DOWNWARD
1420 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1423 /* Check stack bounds if necessary. */
1424 if (crtl
->limit_stack
)
1427 rtx space_available
= gen_label_rtx ();
1428 #ifdef STACK_GROWS_DOWNWARD
1429 available
= expand_binop (Pmode
, sub_optab
,
1430 stack_pointer_rtx
, stack_limit_rtx
,
1431 NULL_RTX
, 1, OPTAB_WIDEN
);
1433 available
= expand_binop (Pmode
, sub_optab
,
1434 stack_limit_rtx
, stack_pointer_rtx
,
1435 NULL_RTX
, 1, OPTAB_WIDEN
);
1437 emit_cmp_and_jump_insns (available
, size
, GEU
, NULL_RTX
, Pmode
, 1,
1441 emit_insn (gen_trap ());
1444 error ("stack limits not supported on this target");
1446 emit_label (space_available
);
1449 saved_stack_pointer_delta
= stack_pointer_delta
;
1450 if (flag_stack_check
&& STACK_CHECK_MOVING_SP
)
1451 anti_adjust_stack_and_probe (size
, false);
1453 anti_adjust_stack (size
);
1454 /* Even if size is constant, don't modify stack_pointer_delta.
1455 The constant size alloca should preserve
1456 crtl->preferred_stack_boundary alignment. */
1457 stack_pointer_delta
= saved_stack_pointer_delta
;
1459 #ifdef STACK_GROWS_DOWNWARD
1460 emit_move_insn (target
, virtual_stack_dynamic_rtx
);
1464 /* Finish up the split stack handling. */
1465 if (final_label
!= NULL_RTX
)
1467 gcc_assert (flag_split_stack
);
1468 emit_move_insn (final_target
, target
);
1469 emit_label (final_label
);
1470 target
= final_target
;
1475 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1476 but we know it can't. So add ourselves and then do
1478 target
= expand_binop (Pmode
, add_optab
, target
,
1479 GEN_INT (required_align
/ BITS_PER_UNIT
- 1),
1480 NULL_RTX
, 1, OPTAB_LIB_WIDEN
);
1481 target
= expand_divmod (0, TRUNC_DIV_EXPR
, Pmode
, target
,
1482 GEN_INT (required_align
/ BITS_PER_UNIT
),
1484 target
= expand_mult (Pmode
, target
,
1485 GEN_INT (required_align
/ BITS_PER_UNIT
),
1489 /* Now that we've committed to a return value, mark its alignment. */
1490 mark_reg_pointer (target
, required_align
);
1492 /* Record the new stack level for nonlocal gotos. */
1493 if (cfun
->nonlocal_goto_save_area
!= 0)
1494 update_nonlocal_goto_save_area ();
1499 /* A front end may want to override GCC's stack checking by providing a
1500 run-time routine to call to check the stack, so provide a mechanism for
1501 calling that routine. */
1503 static GTY(()) rtx stack_check_libfunc
;
1506 set_stack_check_libfunc (const char *libfunc_name
)
1508 gcc_assert (stack_check_libfunc
== NULL_RTX
);
1509 stack_check_libfunc
= gen_rtx_SYMBOL_REF (Pmode
, libfunc_name
);
1512 /* Emit one stack probe at ADDRESS, an address within the stack. */
1515 emit_stack_probe (rtx address
)
1517 rtx memref
= gen_rtx_MEM (word_mode
, address
);
1519 MEM_VOLATILE_P (memref
) = 1;
1521 /* See if we have an insn to probe the stack. */
1522 #ifdef HAVE_probe_stack
1523 if (HAVE_probe_stack
)
1524 emit_insn (gen_probe_stack (memref
));
1527 emit_move_insn (memref
, const0_rtx
);
1530 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1531 FIRST is a constant and size is a Pmode RTX. These are offsets from
1532 the current stack pointer. STACK_GROWS_DOWNWARD says whether to add
1533 or subtract them from the stack pointer. */
1535 #define PROBE_INTERVAL (1 << STACK_CHECK_PROBE_INTERVAL_EXP)
1537 #ifdef STACK_GROWS_DOWNWARD
1538 #define STACK_GROW_OP MINUS
1539 #define STACK_GROW_OPTAB sub_optab
1540 #define STACK_GROW_OFF(off) -(off)
1542 #define STACK_GROW_OP PLUS
1543 #define STACK_GROW_OPTAB add_optab
1544 #define STACK_GROW_OFF(off) (off)
1548 probe_stack_range (HOST_WIDE_INT first
, rtx size
)
1550 /* First ensure SIZE is Pmode. */
1551 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1552 size
= convert_to_mode (Pmode
, size
, 1);
1554 /* Next see if we have a function to check the stack. */
1555 if (stack_check_libfunc
)
1557 rtx addr
= memory_address (Pmode
,
1558 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1560 plus_constant (size
, first
)));
1561 emit_library_call (stack_check_libfunc
, LCT_NORMAL
, VOIDmode
, 1, addr
,
1566 /* Next see if we have an insn to check the stack. */
1567 #ifdef HAVE_check_stack
1568 if (HAVE_check_stack
)
1570 struct expand_operand ops
[1];
1571 rtx addr
= memory_address (Pmode
,
1572 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1574 plus_constant (size
, first
)));
1576 create_input_operand (&ops
[0], addr
, Pmode
);
1577 if (maybe_expand_insn (CODE_FOR_check_stack
, 1, ops
))
1582 /* Otherwise we have to generate explicit probes. If we have a constant
1583 small number of them to generate, that's the easy case. */
1584 else if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1586 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1589 /* Probe at FIRST + N * PROBE_INTERVAL for values of N from 1 until
1590 it exceeds SIZE. If only one probe is needed, this will not
1591 generate any code. Then probe at FIRST + SIZE. */
1592 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1594 addr
= memory_address (Pmode
,
1595 plus_constant (stack_pointer_rtx
,
1596 STACK_GROW_OFF (first
+ i
)));
1597 emit_stack_probe (addr
);
1600 addr
= memory_address (Pmode
,
1601 plus_constant (stack_pointer_rtx
,
1602 STACK_GROW_OFF (first
+ isize
)));
1603 emit_stack_probe (addr
);
1606 /* In the variable case, do the same as above, but in a loop. Note that we
1607 must be extra careful with variables wrapping around because we might be
1608 at the very top (or the very bottom) of the address space and we have to
1609 be able to handle this case properly; in particular, we use an equality
1610 test for the loop condition. */
1613 rtx rounded_size
, rounded_size_op
, test_addr
, last_addr
, temp
;
1614 rtx loop_lab
= gen_label_rtx ();
1615 rtx end_lab
= gen_label_rtx ();
1618 /* Step 1: round SIZE to the previous multiple of the interval. */
1620 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1622 = simplify_gen_binary (AND
, Pmode
, size
, GEN_INT (-PROBE_INTERVAL
));
1623 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1626 /* Step 2: compute initial and final value of the loop counter. */
1628 /* TEST_ADDR = SP + FIRST. */
1629 test_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1631 GEN_INT (first
)), NULL_RTX
);
1633 /* LAST_ADDR = SP + FIRST + ROUNDED_SIZE. */
1634 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1636 rounded_size_op
), NULL_RTX
);
1641 while (TEST_ADDR != LAST_ADDR)
1643 TEST_ADDR = TEST_ADDR + PROBE_INTERVAL
1647 probes at FIRST + N * PROBE_INTERVAL for values of N from 1
1648 until it is equal to ROUNDED_SIZE. */
1650 emit_label (loop_lab
);
1652 /* Jump to END_LAB if TEST_ADDR == LAST_ADDR. */
1653 emit_cmp_and_jump_insns (test_addr
, last_addr
, EQ
, NULL_RTX
, Pmode
, 1,
1656 /* TEST_ADDR = TEST_ADDR + PROBE_INTERVAL. */
1657 temp
= expand_binop (Pmode
, STACK_GROW_OPTAB
, test_addr
,
1658 GEN_INT (PROBE_INTERVAL
), test_addr
,
1661 gcc_assert (temp
== test_addr
);
1663 /* Probe at TEST_ADDR. */
1664 emit_stack_probe (test_addr
);
1666 emit_jump (loop_lab
);
1668 emit_label (end_lab
);
1671 /* Step 4: probe at FIRST + SIZE if we cannot assert at compile-time
1672 that SIZE is equal to ROUNDED_SIZE. */
1674 /* TEMP = SIZE - ROUNDED_SIZE. */
1675 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1676 if (temp
!= const0_rtx
)
1680 if (CONST_INT_P (temp
))
1682 /* Use [base + disp} addressing mode if supported. */
1683 HOST_WIDE_INT offset
= INTVAL (temp
);
1684 addr
= memory_address (Pmode
,
1685 plus_constant (last_addr
,
1686 STACK_GROW_OFF (offset
)));
1690 /* Manual CSE if the difference is not known at compile-time. */
1691 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1692 addr
= memory_address (Pmode
,
1693 gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1697 emit_stack_probe (addr
);
1702 /* Adjust the stack pointer by minus SIZE (an rtx for a number of bytes)
1703 while probing it. This pushes when SIZE is positive. SIZE need not
1704 be constant. If ADJUST_BACK is true, adjust back the stack pointer
1705 by plus SIZE at the end. */
1708 anti_adjust_stack_and_probe (rtx size
, bool adjust_back
)
1710 /* We skip the probe for the first interval + a small dope of 4 words and
1711 probe that many bytes past the specified size to maintain a protection
1712 area at the botton of the stack. */
1713 const int dope
= 4 * UNITS_PER_WORD
;
1715 /* First ensure SIZE is Pmode. */
1716 if (GET_MODE (size
) != VOIDmode
&& GET_MODE (size
) != Pmode
)
1717 size
= convert_to_mode (Pmode
, size
, 1);
1719 /* If we have a constant small number of probes to generate, that's the
1721 if (CONST_INT_P (size
) && INTVAL (size
) < 7 * PROBE_INTERVAL
)
1723 HOST_WIDE_INT isize
= INTVAL (size
), i
;
1724 bool first_probe
= true;
1726 /* Adjust SP and probe at PROBE_INTERVAL + N * PROBE_INTERVAL for
1727 values of N from 1 until it exceeds SIZE. If only one probe is
1728 needed, this will not generate any code. Then adjust and probe
1729 to PROBE_INTERVAL + SIZE. */
1730 for (i
= PROBE_INTERVAL
; i
< isize
; i
+= PROBE_INTERVAL
)
1734 anti_adjust_stack (GEN_INT (2 * PROBE_INTERVAL
+ dope
));
1735 first_probe
= false;
1738 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1739 emit_stack_probe (stack_pointer_rtx
);
1743 anti_adjust_stack (plus_constant (size
, PROBE_INTERVAL
+ dope
));
1745 anti_adjust_stack (plus_constant (size
, PROBE_INTERVAL
- i
));
1746 emit_stack_probe (stack_pointer_rtx
);
1749 /* In the variable case, do the same as above, but in a loop. Note that we
1750 must be extra careful with variables wrapping around because we might be
1751 at the very top (or the very bottom) of the address space and we have to
1752 be able to handle this case properly; in particular, we use an equality
1753 test for the loop condition. */
1756 rtx rounded_size
, rounded_size_op
, last_addr
, temp
;
1757 rtx loop_lab
= gen_label_rtx ();
1758 rtx end_lab
= gen_label_rtx ();
1761 /* Step 1: round SIZE to the previous multiple of the interval. */
1763 /* ROUNDED_SIZE = SIZE & -PROBE_INTERVAL */
1765 = simplify_gen_binary (AND
, Pmode
, size
, GEN_INT (-PROBE_INTERVAL
));
1766 rounded_size_op
= force_operand (rounded_size
, NULL_RTX
);
1769 /* Step 2: compute initial and final value of the loop counter. */
1771 /* SP = SP_0 + PROBE_INTERVAL. */
1772 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1774 /* LAST_ADDR = SP_0 + PROBE_INTERVAL + ROUNDED_SIZE. */
1775 last_addr
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP
, Pmode
,
1777 rounded_size_op
), NULL_RTX
);
1782 while (SP != LAST_ADDR)
1784 SP = SP + PROBE_INTERVAL
1788 adjusts SP and probes at PROBE_INTERVAL + N * PROBE_INTERVAL for
1789 values of N from 1 until it is equal to ROUNDED_SIZE. */
1791 emit_label (loop_lab
);
1793 /* Jump to END_LAB if SP == LAST_ADDR. */
1794 emit_cmp_and_jump_insns (stack_pointer_rtx
, last_addr
, EQ
, NULL_RTX
,
1797 /* SP = SP + PROBE_INTERVAL and probe at SP. */
1798 anti_adjust_stack (GEN_INT (PROBE_INTERVAL
));
1799 emit_stack_probe (stack_pointer_rtx
);
1801 emit_jump (loop_lab
);
1803 emit_label (end_lab
);
1806 /* Step 4: adjust SP and probe at PROBE_INTERVAL + SIZE if we cannot
1807 assert at compile-time that SIZE is equal to ROUNDED_SIZE. */
1809 /* TEMP = SIZE - ROUNDED_SIZE. */
1810 temp
= simplify_gen_binary (MINUS
, Pmode
, size
, rounded_size
);
1811 if (temp
!= const0_rtx
)
1813 /* Manual CSE if the difference is not known at compile-time. */
1814 if (GET_CODE (temp
) != CONST_INT
)
1815 temp
= gen_rtx_MINUS (Pmode
, size
, rounded_size_op
);
1816 anti_adjust_stack (temp
);
1817 emit_stack_probe (stack_pointer_rtx
);
1821 /* Adjust back and account for the additional first interval. */
1823 adjust_stack (plus_constant (size
, PROBE_INTERVAL
+ dope
));
1825 adjust_stack (GEN_INT (PROBE_INTERVAL
+ dope
));
1828 /* Return an rtx representing the register or memory location
1829 in which a scalar value of data type VALTYPE
1830 was returned by a function call to function FUNC.
1831 FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
1832 function is known, otherwise 0.
1833 OUTGOING is 1 if on a machine with register windows this function
1834 should return the register in which the function will put its result
1838 hard_function_value (const_tree valtype
, const_tree func
, const_tree fntype
,
1839 int outgoing ATTRIBUTE_UNUSED
)
1843 val
= targetm
.calls
.function_value (valtype
, func
? func
: fntype
, outgoing
);
1846 && GET_MODE (val
) == BLKmode
)
1848 unsigned HOST_WIDE_INT bytes
= int_size_in_bytes (valtype
);
1849 enum machine_mode tmpmode
;
1851 /* int_size_in_bytes can return -1. We don't need a check here
1852 since the value of bytes will then be large enough that no
1853 mode will match anyway. */
1855 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
1856 tmpmode
!= VOIDmode
;
1857 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
1859 /* Have we found a large enough mode? */
1860 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
1864 /* No suitable mode found. */
1865 gcc_assert (tmpmode
!= VOIDmode
);
1867 PUT_MODE (val
, tmpmode
);
1872 /* Return an rtx representing the register or memory location
1873 in which a scalar value of mode MODE was returned by a library call. */
1876 hard_libcall_value (enum machine_mode mode
, rtx fun
)
1878 return targetm
.calls
.libcall_value (mode
, fun
);
1881 /* Look up the tree code for a given rtx code
1882 to provide the arithmetic operation for REAL_ARITHMETIC.
1883 The function returns an int because the caller may not know
1884 what `enum tree_code' means. */
1887 rtx_to_tree_code (enum rtx_code code
)
1889 enum tree_code tcode
;
1912 tcode
= LAST_AND_UNUSED_TREE_CODE
;
1915 return ((int) tcode
);
1918 #include "gt-explow.h"