1 /* Subroutines for manipulating rtx's in semantically interesting ways.
2 Copyright (C) 1987, 1991, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
32 #include "hard-reg-set.h"
33 #include "insn-config.h"
36 static rtx break_out_memory_refs PARAMS ((rtx));
37 static void emit_stack_probe PARAMS ((rtx));
40 /* Truncate and perhaps sign-extend C as appropriate for MODE. */
43 trunc_int_for_mode (c, mode)
45 enum machine_mode mode;
47 int width = GET_MODE_BITSIZE (mode);
49 /* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
51 return c & 1 ? STORE_FLAG_VALUE : 0;
53 /* Sign-extend for the requested mode. */
55 if (width < HOST_BITS_PER_WIDE_INT)
57 HOST_WIDE_INT sign = 1;
67 /* Return an rtx for the sum of X and the integer C.
69 This function should be used via the `plus_constant' macro. */
72 plus_constant_wide (x, c)
74 register HOST_WIDE_INT c;
76 register RTX_CODE code;
78 register enum machine_mode mode;
94 return GEN_INT (INTVAL (x) + c);
98 unsigned HOST_WIDE_INT l1 = CONST_DOUBLE_LOW (x);
99 HOST_WIDE_INT h1 = CONST_DOUBLE_HIGH (x);
100 unsigned HOST_WIDE_INT l2 = c;
101 HOST_WIDE_INT h2 = c < 0 ? ~0 : 0;
102 unsigned HOST_WIDE_INT lv;
105 add_double (l1, h1, l2, h2, &lv, &hv);
107 return immed_double_const (lv, hv, VOIDmode);
111 /* If this is a reference to the constant pool, try replacing it with
112 a reference to a new constant. If the resulting address isn't
113 valid, don't return it because we have no way to validize it. */
114 if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF
115 && CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)))
118 = force_const_mem (GET_MODE (x),
119 plus_constant (get_pool_constant (XEXP (x, 0)),
121 if (memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
127 /* If adding to something entirely constant, set a flag
128 so that we can add a CONST around the result. */
139 /* The interesting case is adding the integer to a sum.
140 Look for constant term in the sum and combine
141 with C. For an integer constant term, we make a combined
142 integer. For a constant term that is not an explicit integer,
143 we cannot really combine, but group them together anyway.
145 Restart or use a recursive call in case the remaining operand is
146 something that we handle specially, such as a SYMBOL_REF.
148 We may not immediately return from the recursive call here, lest
149 all_constant gets lost. */
151 if (GET_CODE (XEXP (x, 1)) == CONST_INT)
153 c += INTVAL (XEXP (x, 1));
155 if (GET_MODE (x) != VOIDmode)
156 c = trunc_int_for_mode (c, GET_MODE (x));
161 else if (CONSTANT_P (XEXP (x, 1)))
163 x = gen_rtx_PLUS (mode, XEXP (x, 0), plus_constant (XEXP (x, 1), c));
166 else if (find_constant_term_loc (&y))
168 /* We need to be careful since X may be shared and we can't
169 modify it in place. */
170 rtx copy = copy_rtx (x);
171 rtx *const_loc = find_constant_term_loc (©);
173 *const_loc = plus_constant (*const_loc, c);
184 x = gen_rtx_PLUS (mode, x, GEN_INT (c));
186 if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
188 else if (all_constant)
189 return gen_rtx_CONST (mode, x);
194 /* If X is a sum, return a new sum like X but lacking any constant terms.
195 Add all the removed constant terms into *CONSTPTR.
196 X itself is not altered. The result != X if and only if
197 it is not isomorphic to X. */
200 eliminate_constant_term (x, constptr)
207 if (GET_CODE (x) != PLUS)
210 /* First handle constants appearing at this level explicitly. */
211 if (GET_CODE (XEXP (x, 1)) == CONST_INT
212 && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr,
214 && GET_CODE (tem) == CONST_INT)
217 return eliminate_constant_term (XEXP (x, 0), constptr);
221 x0 = eliminate_constant_term (XEXP (x, 0), &tem);
222 x1 = eliminate_constant_term (XEXP (x, 1), &tem);
223 if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0))
224 && 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x),
226 && GET_CODE (tem) == CONST_INT)
229 return gen_rtx_PLUS (GET_MODE (x), x0, x1);
235 /* Returns the insn that next references REG after INSN, or 0
236 if REG is clobbered before next referenced or we cannot find
237 an insn that references REG in a straight-line piece of code. */
240 find_next_ref (reg, insn)
246 for (insn = NEXT_INSN (insn); insn; insn = next)
248 next = NEXT_INSN (insn);
249 if (GET_CODE (insn) == NOTE)
251 if (GET_CODE (insn) == CODE_LABEL
252 || GET_CODE (insn) == BARRIER)
254 if (GET_CODE (insn) == INSN
255 || GET_CODE (insn) == JUMP_INSN
256 || GET_CODE (insn) == CALL_INSN)
258 if (reg_set_p (reg, insn))
260 if (reg_mentioned_p (reg, PATTERN (insn)))
262 if (GET_CODE (insn) == JUMP_INSN)
264 if (any_uncondjump_p (insn))
265 next = JUMP_LABEL (insn);
269 if (GET_CODE (insn) == CALL_INSN
270 && REGNO (reg) < FIRST_PSEUDO_REGISTER
271 && call_used_regs[REGNO (reg)])
280 /* Return an rtx for the size in bytes of the value of EXP. */
288 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'd'
289 && DECL_SIZE_UNIT (exp) != 0)
290 size = DECL_SIZE_UNIT (exp);
292 size = size_in_bytes (TREE_TYPE (exp));
294 if (TREE_CODE (size) != INTEGER_CST
295 && contains_placeholder_p (size))
296 size = build (WITH_RECORD_EXPR, sizetype, size, exp);
298 return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype),
299 EXPAND_MEMORY_USE_BAD);
302 /* Return a copy of X in which all memory references
303 and all constants that involve symbol refs
304 have been replaced with new temporary registers.
305 Also emit code to load the memory locations and constants
306 into those registers.
308 If X contains no such constants or memory references,
309 X itself (not a copy) is returned.
311 If a constant is found in the address that is not a legitimate constant
312 in an insn, it is left alone in the hope that it might be valid in the
315 X may contain no arithmetic except addition, subtraction and multiplication.
316 Values returned by expand_expr with 1 for sum_ok fit this constraint. */
319 break_out_memory_refs (x)
322 if (GET_CODE (x) == MEM
323 || (CONSTANT_P (x) && CONSTANT_ADDRESS_P (x)
324 && GET_MODE (x) != VOIDmode))
325 x = force_reg (GET_MODE (x), x);
326 else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
327 || GET_CODE (x) == MULT)
329 register rtx op0 = break_out_memory_refs (XEXP (x, 0));
330 register rtx op1 = break_out_memory_refs (XEXP (x, 1));
332 if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
333 x = gen_rtx_fmt_ee (GET_CODE (x), Pmode, op0, op1);
339 #ifdef POINTERS_EXTEND_UNSIGNED
341 /* Given X, a memory address in ptr_mode, convert it to an address
342 in Pmode, or vice versa (TO_MODE says which way). We take advantage of
343 the fact that pointers are not allowed to overflow by commuting arithmetic
344 operations over conversions so that address arithmetic insns can be
348 convert_memory_address (to_mode, x)
349 enum machine_mode to_mode;
352 enum machine_mode from_mode = to_mode == ptr_mode ? Pmode : ptr_mode;
355 /* Here we handle some special cases. If none of them apply, fall through
356 to the default case. */
357 switch (GET_CODE (x))
364 if (POINTERS_EXTEND_UNSIGNED >= 0
365 && GET_MODE (SUBREG_REG (x)) == to_mode)
366 return SUBREG_REG (x);
370 if (POINTERS_EXTEND_UNSIGNED >= 0)
372 temp = gen_rtx_LABEL_REF (to_mode, XEXP (x, 0));
373 LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x);
379 if (POINTERS_EXTEND_UNSIGNED >= 0)
381 temp = gen_rtx_SYMBOL_REF (to_mode, XSTR (x, 0));
382 SYMBOL_REF_FLAG (temp) = SYMBOL_REF_FLAG (x);
383 CONSTANT_POOL_ADDRESS_P (temp) = CONSTANT_POOL_ADDRESS_P (x);
384 STRING_POOL_ADDRESS_P (temp) = STRING_POOL_ADDRESS_P (x);
390 if (POINTERS_EXTEND_UNSIGNED >= 0)
391 return gen_rtx_CONST (to_mode,
392 convert_memory_address (to_mode, XEXP (x, 0)));
397 /* For addition the second operand is a small constant, we can safely
398 permute the conversion and addition operation. We can always safely
399 permute them if we are making the address narrower. In addition,
400 always permute the operations if this is a constant. */
401 if (POINTERS_EXTEND_UNSIGNED >= 0
402 && (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)
403 || (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == CONST_INT
404 && (INTVAL (XEXP (x, 1)) + 20000 < 40000
405 || CONSTANT_P (XEXP (x, 0))))))
406 return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
407 convert_memory_address (to_mode, XEXP (x, 0)),
408 convert_memory_address (to_mode, XEXP (x, 1)));
415 return convert_modes (to_mode, from_mode,
416 x, POINTERS_EXTEND_UNSIGNED);
420 /* Given a memory address or facsimile X, construct a new address,
421 currently equivalent, that is stable: future stores won't change it.
423 X must be composed of constants, register and memory references
424 combined with addition, subtraction and multiplication:
425 in other words, just what you can get from expand_expr if sum_ok is 1.
427 Works by making copies of all regs and memory locations used
428 by X and combining them the same way X does.
429 You could also stabilize the reference to this address
430 by copying the address to a register with copy_to_reg;
431 but then you wouldn't get indexed addressing in the reference. */
437 if (GET_CODE (x) == REG)
439 if (REGNO (x) != FRAME_POINTER_REGNUM
440 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
441 && REGNO (x) != HARD_FRAME_POINTER_REGNUM
446 else if (GET_CODE (x) == MEM)
448 else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
449 || GET_CODE (x) == MULT)
451 register rtx op0 = copy_all_regs (XEXP (x, 0));
452 register rtx op1 = copy_all_regs (XEXP (x, 1));
453 if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
454 x = gen_rtx_fmt_ee (GET_CODE (x), Pmode, op0, op1);
459 /* Return something equivalent to X but valid as a memory address
460 for something of mode MODE. When X is not itself valid, this
461 works by copying X or subexpressions of it into registers. */
464 memory_address (mode, x)
465 enum machine_mode mode;
468 register rtx oldx = x;
470 if (GET_CODE (x) == ADDRESSOF)
473 #ifdef POINTERS_EXTEND_UNSIGNED
474 if (GET_MODE (x) == ptr_mode)
475 x = convert_memory_address (Pmode, x);
478 /* By passing constant addresses thru registers
479 we get a chance to cse them. */
480 if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x))
481 x = force_reg (Pmode, x);
483 /* Accept a QUEUED that refers to a REG
484 even though that isn't a valid address.
485 On attempting to put this in an insn we will call protect_from_queue
486 which will turn it into a REG, which is valid. */
487 else if (GET_CODE (x) == QUEUED
488 && GET_CODE (QUEUED_VAR (x)) == REG)
491 /* We get better cse by rejecting indirect addressing at this stage.
492 Let the combiner create indirect addresses where appropriate.
493 For now, generate the code so that the subexpressions useful to share
494 are visible. But not if cse won't be done! */
497 if (! cse_not_expected && GET_CODE (x) != REG)
498 x = break_out_memory_refs (x);
500 /* At this point, any valid address is accepted. */
501 GO_IF_LEGITIMATE_ADDRESS (mode, x, win);
503 /* If it was valid before but breaking out memory refs invalidated it,
504 use it the old way. */
505 if (memory_address_p (mode, oldx))
508 /* Perform machine-dependent transformations on X
509 in certain cases. This is not necessary since the code
510 below can handle all possible cases, but machine-dependent
511 transformations can make better code. */
512 LEGITIMIZE_ADDRESS (x, oldx, mode, win);
514 /* PLUS and MULT can appear in special ways
515 as the result of attempts to make an address usable for indexing.
516 Usually they are dealt with by calling force_operand, below.
517 But a sum containing constant terms is special
518 if removing them makes the sum a valid address:
519 then we generate that address in a register
520 and index off of it. We do this because it often makes
521 shorter code, and because the addresses thus generated
522 in registers often become common subexpressions. */
523 if (GET_CODE (x) == PLUS)
525 rtx constant_term = const0_rtx;
526 rtx y = eliminate_constant_term (x, &constant_term);
527 if (constant_term == const0_rtx
528 || ! memory_address_p (mode, y))
529 x = force_operand (x, NULL_RTX);
532 y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term);
533 if (! memory_address_p (mode, y))
534 x = force_operand (x, NULL_RTX);
540 else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS)
541 x = force_operand (x, NULL_RTX);
543 /* If we have a register that's an invalid address,
544 it must be a hard reg of the wrong class. Copy it to a pseudo. */
545 else if (GET_CODE (x) == REG)
548 /* Last resort: copy the value to a register, since
549 the register is a valid address. */
551 x = force_reg (Pmode, x);
558 if (flag_force_addr && ! cse_not_expected && GET_CODE (x) != REG
559 /* Don't copy an addr via a reg if it is one of our stack slots. */
560 && ! (GET_CODE (x) == PLUS
561 && (XEXP (x, 0) == virtual_stack_vars_rtx
562 || XEXP (x, 0) == virtual_incoming_args_rtx)))
564 if (general_operand (x, Pmode))
565 x = force_reg (Pmode, x);
567 x = force_operand (x, NULL_RTX);
573 /* If we didn't change the address, we are done. Otherwise, mark
574 a reg as a pointer if we have REG or REG + CONST_INT. */
577 else if (GET_CODE (x) == REG)
578 mark_reg_pointer (x, BITS_PER_UNIT);
579 else if (GET_CODE (x) == PLUS
580 && GET_CODE (XEXP (x, 0)) == REG
581 && GET_CODE (XEXP (x, 1)) == CONST_INT)
582 mark_reg_pointer (XEXP (x, 0), BITS_PER_UNIT);
584 /* OLDX may have been the address on a temporary. Update the address
585 to indicate that X is now used. */
586 update_temp_slot_address (oldx, x);
591 /* Like `memory_address' but pretend `flag_force_addr' is 0. */
594 memory_address_noforce (mode, x)
595 enum machine_mode mode;
598 int ambient_force_addr = flag_force_addr;
602 val = memory_address (mode, x);
603 flag_force_addr = ambient_force_addr;
607 /* Convert a mem ref into one with a valid memory address.
608 Pass through anything else unchanged. */
614 if (GET_CODE (ref) != MEM)
616 if (! (flag_force_addr && CONSTANT_ADDRESS_P (XEXP (ref, 0)))
617 && memory_address_p (GET_MODE (ref), XEXP (ref, 0)))
620 /* Don't alter REF itself, since that is probably a stack slot. */
621 return replace_equiv_address (ref, XEXP (ref, 0));
624 /* Given REF, either a MEM or a REG, and T, either the type of X or
625 the expression corresponding to REF, set RTX_UNCHANGING_P if
629 maybe_set_unchanging (ref, t)
633 /* We can set RTX_UNCHANGING_P from TREE_READONLY for decls whose
634 initialization is only executed once, or whose initializer always
635 has the same value. Currently we simplify this to PARM_DECLs in the
636 first case, and decls with TREE_CONSTANT initializers in the second. */
637 if ((TREE_READONLY (t) && DECL_P (t)
638 && (TREE_CODE (t) == PARM_DECL
639 || DECL_INITIAL (t) == NULL_TREE
640 || TREE_CONSTANT (DECL_INITIAL (t))))
641 || TREE_CODE_CLASS (TREE_CODE (t)) == 'c')
642 RTX_UNCHANGING_P (ref) = 1;
645 /* Given REF, a MEM, and T, either the type of X or the expression
646 corresponding to REF, set the memory attributes. OBJECTP is nonzero
647 if we are making a new object of this type. */
650 set_mem_attributes (ref, t, objectp)
657 /* It can happen that type_for_mode was given a mode for which there
658 is no language-level type. In which case it returns NULL, which
663 type = TYPE_P (t) ? t : TREE_TYPE (t);
665 /* Get the alias set from the expression or type (perhaps using a
666 front-end routine) and then copy bits from the type. */
668 /* It is incorrect to set RTX_UNCHANGING_P from TREE_READONLY (type)
669 here, because, in C and C++, the fact that a location is accessed
670 through a const expression does not mean that the value there can
672 set_mem_alias_set (ref, get_alias_set (t));
673 MEM_VOLATILE_P (ref) = TYPE_VOLATILE (type);
674 MEM_IN_STRUCT_P (ref) = AGGREGATE_TYPE_P (type);
676 /* If we are making an object of this type, we know that it is a scalar if
677 the type is not an aggregate. */
678 if (objectp && ! AGGREGATE_TYPE_P (type))
679 MEM_SCALAR_P (ref) = 1;
681 /* If T is a type, this is all we can do. Otherwise, we may be able
682 to deduce some more information about the expression. */
686 maybe_set_unchanging (ref, t);
687 if (TREE_THIS_VOLATILE (t))
688 MEM_VOLATILE_P (ref) = 1;
690 /* Now see if we can say more about whether it's an aggregate or
691 scalar. If we already know it's an aggregate, don't bother. */
692 if (MEM_IN_STRUCT_P (ref))
695 /* Now remove any NOPs: they don't change what the underlying object is.
696 Likewise for SAVE_EXPR. */
697 while (TREE_CODE (t) == NOP_EXPR || TREE_CODE (t) == CONVERT_EXPR
698 || TREE_CODE (t) == NON_LVALUE_EXPR || TREE_CODE (t) == SAVE_EXPR)
699 t = TREE_OPERAND (t, 0);
701 /* Since we already know the type isn't an aggregate, if this is a decl,
702 it must be a scalar. Or if it is a reference into an aggregate,
703 this is part of an aggregate. Otherwise we don't know. */
705 MEM_SCALAR_P (ref) = 1;
706 else if (TREE_CODE (t) == COMPONENT_REF || TREE_CODE (t) == ARRAY_REF
707 || TREE_CODE (t) == ARRAY_RANGE_REF
708 || TREE_CODE (t) == BIT_FIELD_REF)
709 MEM_IN_STRUCT_P (ref) = 1;
712 /* Return a modified copy of X with its memory address copied
713 into a temporary register to protect it from side effects.
714 If X is not a MEM, it is returned unchanged (and not copied).
715 Perhaps even if it is a MEM, if there is no need to change it. */
722 if (GET_CODE (x) != MEM
723 || ! rtx_unstable_p (XEXP (x, 0)))
727 replace_equiv_address (x, force_reg (Pmode, copy_all_regs (XEXP (x, 0))));
730 /* Copy the value or contents of X to a new temp reg and return that reg. */
736 register rtx temp = gen_reg_rtx (GET_MODE (x));
738 /* If not an operand, must be an address with PLUS and MULT so
739 do the computation. */
740 if (! general_operand (x, VOIDmode))
741 x = force_operand (x, temp);
744 emit_move_insn (temp, x);
749 /* Like copy_to_reg but always give the new register mode Pmode
750 in case X is a constant. */
756 return copy_to_mode_reg (Pmode, x);
759 /* Like copy_to_reg but always give the new register mode MODE
760 in case X is a constant. */
763 copy_to_mode_reg (mode, x)
764 enum machine_mode mode;
767 register rtx temp = gen_reg_rtx (mode);
769 /* If not an operand, must be an address with PLUS and MULT so
770 do the computation. */
771 if (! general_operand (x, VOIDmode))
772 x = force_operand (x, temp);
774 if (GET_MODE (x) != mode && GET_MODE (x) != VOIDmode)
777 emit_move_insn (temp, x);
781 /* Load X into a register if it is not already one.
782 Use mode MODE for the register.
783 X should be valid for mode MODE, but it may be a constant which
784 is valid for all integer modes; that's why caller must specify MODE.
786 The caller must not alter the value in the register we return,
787 since we mark it as a "constant" register. */
791 enum machine_mode mode;
794 register rtx temp, insn, set;
796 if (GET_CODE (x) == REG)
799 temp = gen_reg_rtx (mode);
801 if (! general_operand (x, mode))
802 x = force_operand (x, NULL_RTX);
804 insn = emit_move_insn (temp, x);
806 /* Let optimizers know that TEMP's value never changes
807 and that X can be substituted for it. Don't get confused
808 if INSN set something else (such as a SUBREG of TEMP). */
810 && (set = single_set (insn)) != 0
811 && SET_DEST (set) == temp)
813 rtx note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
818 REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUAL, x, REG_NOTES (insn));
823 /* If X is a memory ref, copy its contents to a new temp reg and return
824 that reg. Otherwise, return X. */
832 if (GET_CODE (x) != MEM || GET_MODE (x) == BLKmode)
835 temp = gen_reg_rtx (GET_MODE (x));
836 emit_move_insn (temp, x);
840 /* Copy X to TARGET (if it's nonzero and a reg)
841 or to a new temp reg and return that reg.
842 MODE is the mode to use for X in case it is a constant. */
845 copy_to_suggested_reg (x, target, mode)
847 enum machine_mode mode;
851 if (target && GET_CODE (target) == REG)
854 temp = gen_reg_rtx (mode);
856 emit_move_insn (temp, x);
860 /* Return the mode to use to store a scalar of TYPE and MODE.
861 PUNSIGNEDP points to the signedness of the type and may be adjusted
862 to show what signedness to use on extension operations.
864 FOR_CALL is non-zero if this call is promoting args for a call. */
867 promote_mode (type, mode, punsignedp, for_call)
869 enum machine_mode mode;
871 int for_call ATTRIBUTE_UNUSED;
873 enum tree_code code = TREE_CODE (type);
874 int unsignedp = *punsignedp;
876 #ifdef PROMOTE_FOR_CALL_ONLY
884 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
885 case CHAR_TYPE: case REAL_TYPE: case OFFSET_TYPE:
886 PROMOTE_MODE (mode, unsignedp, type);
890 #ifdef POINTERS_EXTEND_UNSIGNED
894 unsignedp = POINTERS_EXTEND_UNSIGNED;
902 *punsignedp = unsignedp;
906 /* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
907 This pops when ADJUST is positive. ADJUST need not be constant. */
910 adjust_stack (adjust)
914 adjust = protect_from_queue (adjust, 0);
916 if (adjust == const0_rtx)
919 /* We expect all variable sized adjustments to be multiple of
920 PREFERRED_STACK_BOUNDARY. */
921 if (GET_CODE (adjust) == CONST_INT)
922 stack_pointer_delta -= INTVAL (adjust);
924 temp = expand_binop (Pmode,
925 #ifdef STACK_GROWS_DOWNWARD
930 stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
933 if (temp != stack_pointer_rtx)
934 emit_move_insn (stack_pointer_rtx, temp);
937 /* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
938 This pushes when ADJUST is positive. ADJUST need not be constant. */
941 anti_adjust_stack (adjust)
945 adjust = protect_from_queue (adjust, 0);
947 if (adjust == const0_rtx)
950 /* We expect all variable sized adjustments to be multiple of
951 PREFERRED_STACK_BOUNDARY. */
952 if (GET_CODE (adjust) == CONST_INT)
953 stack_pointer_delta += INTVAL (adjust);
955 temp = expand_binop (Pmode,
956 #ifdef STACK_GROWS_DOWNWARD
961 stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
964 if (temp != stack_pointer_rtx)
965 emit_move_insn (stack_pointer_rtx, temp);
968 /* Round the size of a block to be pushed up to the boundary required
969 by this machine. SIZE is the desired size, which need not be constant. */
975 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
978 if (GET_CODE (size) == CONST_INT)
980 int new = (INTVAL (size) + align - 1) / align * align;
981 if (INTVAL (size) != new)
982 size = GEN_INT (new);
986 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
987 but we know it can't. So add ourselves and then do
989 size = expand_binop (Pmode, add_optab, size, GEN_INT (align - 1),
990 NULL_RTX, 1, OPTAB_LIB_WIDEN);
991 size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, GEN_INT (align),
993 size = expand_mult (Pmode, size, GEN_INT (align), NULL_RTX, 1);
998 /* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
999 to a previously-created save area. If no save area has been allocated,
1000 this function will allocate one. If a save area is specified, it
1001 must be of the proper mode.
1003 The insns are emitted after insn AFTER, if nonzero, otherwise the insns
1004 are emitted at the current position. */
1007 emit_stack_save (save_level, psave, after)
1008 enum save_level save_level;
1013 /* The default is that we use a move insn and save in a Pmode object. */
1014 rtx (*fcn) PARAMS ((rtx, rtx)) = gen_move_insn;
1015 enum machine_mode mode = STACK_SAVEAREA_MODE (save_level);
1017 /* See if this machine has anything special to do for this kind of save. */
1020 #ifdef HAVE_save_stack_block
1022 if (HAVE_save_stack_block)
1023 fcn = gen_save_stack_block;
1026 #ifdef HAVE_save_stack_function
1028 if (HAVE_save_stack_function)
1029 fcn = gen_save_stack_function;
1032 #ifdef HAVE_save_stack_nonlocal
1034 if (HAVE_save_stack_nonlocal)
1035 fcn = gen_save_stack_nonlocal;
1042 /* If there is no save area and we have to allocate one, do so. Otherwise
1043 verify the save area is the proper mode. */
1047 if (mode != VOIDmode)
1049 if (save_level == SAVE_NONLOCAL)
1050 *psave = sa = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
1052 *psave = sa = gen_reg_rtx (mode);
1057 if (mode == VOIDmode || GET_MODE (sa) != mode)
1066 /* We must validize inside the sequence, to ensure that any instructions
1067 created by the validize call also get moved to the right place. */
1069 sa = validize_mem (sa);
1070 emit_insn (fcn (sa, stack_pointer_rtx));
1071 seq = gen_sequence ();
1073 emit_insn_after (seq, after);
1078 sa = validize_mem (sa);
1079 emit_insn (fcn (sa, stack_pointer_rtx));
1083 /* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
1084 area made by emit_stack_save. If it is zero, we have nothing to do.
1086 Put any emitted insns after insn AFTER, if nonzero, otherwise at
1087 current position. */
1090 emit_stack_restore (save_level, sa, after)
1091 enum save_level save_level;
1095 /* The default is that we use a move insn. */
1096 rtx (*fcn) PARAMS ((rtx, rtx)) = gen_move_insn;
1098 /* See if this machine has anything special to do for this kind of save. */
1101 #ifdef HAVE_restore_stack_block
1103 if (HAVE_restore_stack_block)
1104 fcn = gen_restore_stack_block;
1107 #ifdef HAVE_restore_stack_function
1109 if (HAVE_restore_stack_function)
1110 fcn = gen_restore_stack_function;
1113 #ifdef HAVE_restore_stack_nonlocal
1115 if (HAVE_restore_stack_nonlocal)
1116 fcn = gen_restore_stack_nonlocal;
1124 sa = validize_mem (sa);
1131 emit_insn (fcn (stack_pointer_rtx, sa));
1132 seq = gen_sequence ();
1134 emit_insn_after (seq, after);
1137 emit_insn (fcn (stack_pointer_rtx, sa));
1140 #ifdef SETJMP_VIA_SAVE_AREA
1141 /* Optimize RTL generated by allocate_dynamic_stack_space for targets
1142 where SETJMP_VIA_SAVE_AREA is true. The problem is that on these
1143 platforms, the dynamic stack space used can corrupt the original
1144 frame, thus causing a crash if a longjmp unwinds to it. */
1147 optimize_save_area_alloca (insns)
1152 for (insn = insns; insn; insn = NEXT_INSN(insn))
1156 if (GET_CODE (insn) != INSN)
1159 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
1161 if (REG_NOTE_KIND (note) != REG_SAVE_AREA)
1164 if (!current_function_calls_setjmp)
1166 rtx pat = PATTERN (insn);
1168 /* If we do not see the note in a pattern matching
1169 these precise characteristics, we did something
1170 entirely wrong in allocate_dynamic_stack_space.
1172 Note, one way this could happen is if SETJMP_VIA_SAVE_AREA
1173 was defined on a machine where stacks grow towards higher
1176 Right now only supported port with stack that grow upward
1177 is the HPPA and it does not define SETJMP_VIA_SAVE_AREA. */
1178 if (GET_CODE (pat) != SET
1179 || SET_DEST (pat) != stack_pointer_rtx
1180 || GET_CODE (SET_SRC (pat)) != MINUS
1181 || XEXP (SET_SRC (pat), 0) != stack_pointer_rtx)
1184 /* This will now be transformed into a (set REG REG)
1185 so we can just blow away all the other notes. */
1186 XEXP (SET_SRC (pat), 1) = XEXP (note, 0);
1187 REG_NOTES (insn) = NULL_RTX;
1191 /* setjmp was called, we must remove the REG_SAVE_AREA
1192 note so that later passes do not get confused by its
1194 if (note == REG_NOTES (insn))
1196 REG_NOTES (insn) = XEXP (note, 1);
1202 for (srch = REG_NOTES (insn); srch; srch = XEXP (srch, 1))
1203 if (XEXP (srch, 1) == note)
1206 if (srch == NULL_RTX)
1209 XEXP (srch, 1) = XEXP (note, 1);
1212 /* Once we've seen the note of interest, we need not look at
1213 the rest of them. */
1218 #endif /* SETJMP_VIA_SAVE_AREA */
1220 /* Return an rtx representing the address of an area of memory dynamically
1221 pushed on the stack. This region of memory is always aligned to
1222 a multiple of BIGGEST_ALIGNMENT.
1224 Any required stack pointer alignment is preserved.
1226 SIZE is an rtx representing the size of the area.
1227 TARGET is a place in which the address can be placed.
1229 KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */
1232 allocate_dynamic_stack_space (size, target, known_align)
1237 #ifdef SETJMP_VIA_SAVE_AREA
1238 rtx setjmpless_size = NULL_RTX;
1241 /* If we're asking for zero bytes, it doesn't matter what we point
1242 to since we can't dereference it. But return a reasonable
1244 if (size == const0_rtx)
1245 return virtual_stack_dynamic_rtx;
1247 /* Otherwise, show we're calling alloca or equivalent. */
1248 current_function_calls_alloca = 1;
1250 /* Ensure the size is in the proper mode. */
1251 if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
1252 size = convert_to_mode (Pmode, size, 1);
1254 /* We can't attempt to minimize alignment necessary, because we don't
1255 know the final value of preferred_stack_boundary yet while executing
1257 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
1259 /* We will need to ensure that the address we return is aligned to
1260 BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
1261 always know its final value at this point in the compilation (it
1262 might depend on the size of the outgoing parameter lists, for
1263 example), so we must align the value to be returned in that case.
1264 (Note that STACK_DYNAMIC_OFFSET will have a default non-zero value if
1265 STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
1266 We must also do an alignment operation on the returned value if
1267 the stack pointer alignment is less strict that BIGGEST_ALIGNMENT.
1269 If we have to align, we must leave space in SIZE for the hole
1270 that might result from the alignment operation. */
1272 #if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
1273 #define MUST_ALIGN 1
1275 #define MUST_ALIGN (PREFERRED_STACK_BOUNDARY < BIGGEST_ALIGNMENT)
1280 = force_operand (plus_constant (size,
1281 BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
1284 #ifdef SETJMP_VIA_SAVE_AREA
1285 /* If setjmp restores regs from a save area in the stack frame,
1286 avoid clobbering the reg save area. Note that the offset of
1287 virtual_incoming_args_rtx includes the preallocated stack args space.
1288 It would be no problem to clobber that, but it's on the wrong side
1289 of the old save area. */
1292 = expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx,
1293 stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN);
1295 if (!current_function_calls_setjmp)
1297 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
1299 /* See optimize_save_area_alloca to understand what is being
1302 /* ??? Code below assumes that the save area needs maximal
1303 alignment. This constraint may be too strong. */
1304 if (PREFERRED_STACK_BOUNDARY != BIGGEST_ALIGNMENT)
1307 if (GET_CODE (size) == CONST_INT)
1309 HOST_WIDE_INT new = INTVAL (size) / align * align;
1311 if (INTVAL (size) != new)
1312 setjmpless_size = GEN_INT (new);
1314 setjmpless_size = size;
1318 /* Since we know overflow is not possible, we avoid using
1319 CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */
1320 setjmpless_size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size,
1321 GEN_INT (align), NULL_RTX, 1);
1322 setjmpless_size = expand_mult (Pmode, setjmpless_size,
1323 GEN_INT (align), NULL_RTX, 1);
1325 /* Our optimization works based upon being able to perform a simple
1326 transformation of this RTL into a (set REG REG) so make sure things
1327 did in fact end up in a REG. */
1328 if (!register_operand (setjmpless_size, Pmode))
1329 setjmpless_size = force_reg (Pmode, setjmpless_size);
1332 size = expand_binop (Pmode, add_optab, size, dynamic_offset,
1333 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1335 #endif /* SETJMP_VIA_SAVE_AREA */
1337 /* Round the size to a multiple of the required stack alignment.
1338 Since the stack if presumed to be rounded before this allocation,
1339 this will maintain the required alignment.
1341 If the stack grows downward, we could save an insn by subtracting
1342 SIZE from the stack pointer and then aligning the stack pointer.
1343 The problem with this is that the stack pointer may be unaligned
1344 between the execution of the subtraction and alignment insns and
1345 some machines do not allow this. Even on those that do, some
1346 signal handlers malfunction if a signal should occur between those
1347 insns. Since this is an extremely rare event, we have no reliable
1348 way of knowing which systems have this problem. So we avoid even
1349 momentarily mis-aligning the stack. */
1351 /* If we added a variable amount to SIZE,
1352 we can no longer assume it is aligned. */
1353 #if !defined (SETJMP_VIA_SAVE_AREA)
1354 if (MUST_ALIGN || known_align % PREFERRED_STACK_BOUNDARY != 0)
1356 size = round_push (size);
1358 do_pending_stack_adjust ();
1360 /* We ought to be called always on the toplevel and stack ought to be aligned
1362 if (stack_pointer_delta % (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT))
1365 /* If needed, check that we have the required amount of stack. Take into
1366 account what has already been checked. */
1367 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
1368 probe_stack_range (STACK_CHECK_MAX_FRAME_SIZE + STACK_CHECK_PROTECT, size);
1370 /* Don't use a TARGET that isn't a pseudo or is the wrong mode. */
1371 if (target == 0 || GET_CODE (target) != REG
1372 || REGNO (target) < FIRST_PSEUDO_REGISTER
1373 || GET_MODE (target) != Pmode)
1374 target = gen_reg_rtx (Pmode);
1376 mark_reg_pointer (target, known_align);
1378 /* Perform the required allocation from the stack. Some systems do
1379 this differently than simply incrementing/decrementing from the
1380 stack pointer, such as acquiring the space by calling malloc(). */
1381 #ifdef HAVE_allocate_stack
1382 if (HAVE_allocate_stack)
1384 enum machine_mode mode = STACK_SIZE_MODE;
1385 insn_operand_predicate_fn pred;
1387 pred = insn_data[(int) CODE_FOR_allocate_stack].operand[0].predicate;
1388 if (pred && ! ((*pred) (target, Pmode)))
1389 #ifdef POINTERS_EXTEND_UNSIGNED
1390 target = convert_memory_address (Pmode, target);
1392 target = copy_to_mode_reg (Pmode, target);
1395 if (mode == VOIDmode)
1398 pred = insn_data[(int) CODE_FOR_allocate_stack].operand[1].predicate;
1399 if (pred && ! ((*pred) (size, mode)))
1400 size = copy_to_mode_reg (mode, size);
1402 emit_insn (gen_allocate_stack (target, size));
1407 #ifndef STACK_GROWS_DOWNWARD
1408 emit_move_insn (target, virtual_stack_dynamic_rtx);
1411 /* Check stack bounds if necessary. */
1412 if (current_function_limit_stack)
1415 rtx space_available = gen_label_rtx ();
1416 #ifdef STACK_GROWS_DOWNWARD
1417 available = expand_binop (Pmode, sub_optab,
1418 stack_pointer_rtx, stack_limit_rtx,
1419 NULL_RTX, 1, OPTAB_WIDEN);
1421 available = expand_binop (Pmode, sub_optab,
1422 stack_limit_rtx, stack_pointer_rtx,
1423 NULL_RTX, 1, OPTAB_WIDEN);
1425 emit_cmp_and_jump_insns (available, size, GEU, NULL_RTX, Pmode, 1,
1426 0, space_available);
1429 emit_insn (gen_trap ());
1432 error ("stack limits not supported on this target");
1434 emit_label (space_available);
1437 anti_adjust_stack (size);
1438 #ifdef SETJMP_VIA_SAVE_AREA
1439 if (setjmpless_size != NULL_RTX)
1441 rtx note_target = get_last_insn ();
1443 REG_NOTES (note_target)
1444 = gen_rtx_EXPR_LIST (REG_SAVE_AREA, setjmpless_size,
1445 REG_NOTES (note_target));
1447 #endif /* SETJMP_VIA_SAVE_AREA */
1449 #ifdef STACK_GROWS_DOWNWARD
1450 emit_move_insn (target, virtual_stack_dynamic_rtx);
1456 /* CEIL_DIV_EXPR needs to worry about the addition overflowing,
1457 but we know it can't. So add ourselves and then do
1459 target = expand_binop (Pmode, add_optab, target,
1460 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
1461 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1462 target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target,
1463 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
1465 target = expand_mult (Pmode, target,
1466 GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
1470 /* Some systems require a particular insn to refer to the stack
1471 to make the pages exist. */
1474 emit_insn (gen_probe ());
1477 /* Record the new stack level for nonlocal gotos. */
1478 if (nonlocal_goto_handler_slots != 0)
1479 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
1484 /* A front end may want to override GCC's stack checking by providing a
1485 run-time routine to call to check the stack, so provide a mechanism for
1486 calling that routine. */
1488 static rtx stack_check_libfunc;
1491 set_stack_check_libfunc (libfunc)
1494 stack_check_libfunc = libfunc;
1497 /* Emit one stack probe at ADDRESS, an address within the stack. */
1500 emit_stack_probe (address)
1503 rtx memref = gen_rtx_MEM (word_mode, address);
1505 MEM_VOLATILE_P (memref) = 1;
1507 if (STACK_CHECK_PROBE_LOAD)
1508 emit_move_insn (gen_reg_rtx (word_mode), memref);
1510 emit_move_insn (memref, const0_rtx);
1513 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
1514 FIRST is a constant and size is a Pmode RTX. These are offsets from the
1515 current stack pointer. STACK_GROWS_DOWNWARD says whether to add or
1516 subtract from the stack. If SIZE is constant, this is done
1517 with a fixed number of probes. Otherwise, we must make a loop. */
1519 #ifdef STACK_GROWS_DOWNWARD
1520 #define STACK_GROW_OP MINUS
1522 #define STACK_GROW_OP PLUS
1526 probe_stack_range (first, size)
1527 HOST_WIDE_INT first;
1530 /* First see if the front end has set up a function for us to call to
1532 if (stack_check_libfunc != 0)
1534 rtx addr = memory_address (QImode,
1535 gen_rtx (STACK_GROW_OP, Pmode,
1537 plus_constant (size, first)));
1539 #ifdef POINTERS_EXTEND_UNSIGNED
1540 if (GET_MODE (addr) != ptr_mode)
1541 addr = convert_memory_address (ptr_mode, addr);
1544 emit_library_call (stack_check_libfunc, 0, VOIDmode, 1, addr,
1548 /* Next see if we have an insn to check the stack. Use it if so. */
1549 #ifdef HAVE_check_stack
1550 else if (HAVE_check_stack)
1552 insn_operand_predicate_fn pred;
1554 = force_operand (gen_rtx_STACK_GROW_OP (Pmode,
1556 plus_constant (size, first)),
1559 pred = insn_data[(int) CODE_FOR_check_stack].operand[0].predicate;
1560 if (pred && ! ((*pred) (last_addr, Pmode)))
1561 last_addr = copy_to_mode_reg (Pmode, last_addr);
1563 emit_insn (gen_check_stack (last_addr));
1567 /* If we have to generate explicit probes, see if we have a constant
1568 small number of them to generate. If so, that's the easy case. */
1569 else if (GET_CODE (size) == CONST_INT
1570 && INTVAL (size) < 10 * STACK_CHECK_PROBE_INTERVAL)
1572 HOST_WIDE_INT offset;
1574 /* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL
1575 for values of N from 1 until it exceeds LAST. If only one
1576 probe is needed, this will not generate any code. Then probe
1578 for (offset = first + STACK_CHECK_PROBE_INTERVAL;
1579 offset < INTVAL (size);
1580 offset = offset + STACK_CHECK_PROBE_INTERVAL)
1581 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1585 emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1587 plus_constant (size, first)));
1590 /* In the variable case, do the same as above, but in a loop. We emit loop
1591 notes so that loop optimization can be done. */
1595 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1597 GEN_INT (first + STACK_CHECK_PROBE_INTERVAL)),
1600 = force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
1602 plus_constant (size, first)),
1604 rtx incr = GEN_INT (STACK_CHECK_PROBE_INTERVAL);
1605 rtx loop_lab = gen_label_rtx ();
1606 rtx test_lab = gen_label_rtx ();
1607 rtx end_lab = gen_label_rtx ();
1610 if (GET_CODE (test_addr) != REG
1611 || REGNO (test_addr) < FIRST_PSEUDO_REGISTER)
1612 test_addr = force_reg (Pmode, test_addr);
1614 emit_note (NULL, NOTE_INSN_LOOP_BEG);
1615 emit_jump (test_lab);
1617 emit_label (loop_lab);
1618 emit_stack_probe (test_addr);
1620 emit_note (NULL, NOTE_INSN_LOOP_CONT);
1622 #ifdef STACK_GROWS_DOWNWARD
1623 #define CMP_OPCODE GTU
1624 temp = expand_binop (Pmode, sub_optab, test_addr, incr, test_addr,
1627 #define CMP_OPCODE LTU
1628 temp = expand_binop (Pmode, add_optab, test_addr, incr, test_addr,
1632 if (temp != test_addr)
1635 emit_label (test_lab);
1636 emit_cmp_and_jump_insns (test_addr, last_addr, CMP_OPCODE,
1637 NULL_RTX, Pmode, 1, 0, loop_lab);
1638 emit_jump (end_lab);
1639 emit_note (NULL, NOTE_INSN_LOOP_END);
1640 emit_label (end_lab);
1642 emit_stack_probe (last_addr);
1646 /* Return an rtx representing the register or memory location
1647 in which a scalar value of data type VALTYPE
1648 was returned by a function call to function FUNC.
1649 FUNC is a FUNCTION_DECL node if the precise function is known,
1651 OUTGOING is 1 if on a machine with register windows this function
1652 should return the register in which the function will put its result
1656 hard_function_value (valtype, func, outgoing)
1658 tree func ATTRIBUTE_UNUSED;
1659 int outgoing ATTRIBUTE_UNUSED;
1663 #ifdef FUNCTION_OUTGOING_VALUE
1665 val = FUNCTION_OUTGOING_VALUE (valtype, func);
1668 val = FUNCTION_VALUE (valtype, func);
1670 if (GET_CODE (val) == REG
1671 && GET_MODE (val) == BLKmode)
1673 unsigned HOST_WIDE_INT bytes = int_size_in_bytes (valtype);
1674 enum machine_mode tmpmode;
1676 for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
1677 tmpmode != VOIDmode;
1678 tmpmode = GET_MODE_WIDER_MODE (tmpmode))
1680 /* Have we found a large enough mode? */
1681 if (GET_MODE_SIZE (tmpmode) >= bytes)
1685 /* No suitable mode found. */
1686 if (tmpmode == VOIDmode)
1689 PUT_MODE (val, tmpmode);
1694 /* Return an rtx representing the register or memory location
1695 in which a scalar value of mode MODE was returned by a library call. */
1698 hard_libcall_value (mode)
1699 enum machine_mode mode;
1701 return LIBCALL_VALUE (mode);
1704 /* Look up the tree code for a given rtx code
1705 to provide the arithmetic operation for REAL_ARITHMETIC.
1706 The function returns an int because the caller may not know
1707 what `enum tree_code' means. */
1710 rtx_to_tree_code (code)
1713 enum tree_code tcode;
1736 tcode = LAST_AND_UNUSED_TREE_CODE;
1739 return ((int) tcode);