1551 lines
43 KiB
C
1551 lines
43 KiB
C
/* Subroutines for manipulating rtx's in semantically interesting ways.
|
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Copyright (C) 1987, 1991, 1994, 1995, 1996, 1997, 1998,
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1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
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Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
|
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Software Foundation; either version 2, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
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for more details.
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You should have received a copy of the GNU General Public License
|
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along with GCC; see the file COPYING. If not, write to the Free
|
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Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301, USA. */
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#include "config.h"
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#include "system.h"
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#include "coretypes.h"
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#include "tm.h"
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#include "toplev.h"
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#include "rtl.h"
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#include "tree.h"
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#include "tm_p.h"
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#include "flags.h"
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#include "function.h"
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#include "expr.h"
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#include "optabs.h"
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#include "hard-reg-set.h"
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#include "insn-config.h"
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#include "ggc.h"
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#include "recog.h"
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#include "langhooks.h"
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#include "target.h"
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#include "output.h"
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static rtx break_out_memory_refs (rtx);
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static void emit_stack_probe (rtx);
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/* Truncate and perhaps sign-extend C as appropriate for MODE. */
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HOST_WIDE_INT
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trunc_int_for_mode (HOST_WIDE_INT c, enum machine_mode mode)
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{
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int width = GET_MODE_BITSIZE (mode);
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/* You want to truncate to a _what_? */
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gcc_assert (SCALAR_INT_MODE_P (mode));
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/* Canonicalize BImode to 0 and STORE_FLAG_VALUE. */
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if (mode == BImode)
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return c & 1 ? STORE_FLAG_VALUE : 0;
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/* Sign-extend for the requested mode. */
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if (width < HOST_BITS_PER_WIDE_INT)
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{
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HOST_WIDE_INT sign = 1;
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sign <<= width - 1;
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c &= (sign << 1) - 1;
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c ^= sign;
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c -= sign;
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}
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return c;
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}
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/* Return an rtx for the sum of X and the integer C. */
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rtx
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plus_constant (rtx x, HOST_WIDE_INT c)
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{
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RTX_CODE code;
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rtx y;
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enum machine_mode mode;
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rtx tem;
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int all_constant = 0;
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if (c == 0)
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return x;
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restart:
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code = GET_CODE (x);
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mode = GET_MODE (x);
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y = x;
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switch (code)
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{
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case CONST_INT:
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return GEN_INT (INTVAL (x) + c);
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case CONST_DOUBLE:
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{
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unsigned HOST_WIDE_INT l1 = CONST_DOUBLE_LOW (x);
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HOST_WIDE_INT h1 = CONST_DOUBLE_HIGH (x);
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unsigned HOST_WIDE_INT l2 = c;
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HOST_WIDE_INT h2 = c < 0 ? ~0 : 0;
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unsigned HOST_WIDE_INT lv;
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HOST_WIDE_INT hv;
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add_double (l1, h1, l2, h2, &lv, &hv);
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return immed_double_const (lv, hv, VOIDmode);
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}
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case MEM:
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/* If this is a reference to the constant pool, try replacing it with
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a reference to a new constant. If the resulting address isn't
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valid, don't return it because we have no way to validize it. */
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if (GET_CODE (XEXP (x, 0)) == SYMBOL_REF
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&& CONSTANT_POOL_ADDRESS_P (XEXP (x, 0)))
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{
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tem
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= force_const_mem (GET_MODE (x),
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plus_constant (get_pool_constant (XEXP (x, 0)),
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c));
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if (memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
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return tem;
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}
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break;
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case CONST:
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/* If adding to something entirely constant, set a flag
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so that we can add a CONST around the result. */
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x = XEXP (x, 0);
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all_constant = 1;
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goto restart;
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case SYMBOL_REF:
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case LABEL_REF:
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all_constant = 1;
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break;
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case PLUS:
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/* The interesting case is adding the integer to a sum.
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Look for constant term in the sum and combine
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with C. For an integer constant term, we make a combined
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integer. For a constant term that is not an explicit integer,
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we cannot really combine, but group them together anyway.
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Restart or use a recursive call in case the remaining operand is
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something that we handle specially, such as a SYMBOL_REF.
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We may not immediately return from the recursive call here, lest
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all_constant gets lost. */
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if (GET_CODE (XEXP (x, 1)) == CONST_INT)
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{
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c += INTVAL (XEXP (x, 1));
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if (GET_MODE (x) != VOIDmode)
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c = trunc_int_for_mode (c, GET_MODE (x));
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x = XEXP (x, 0);
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goto restart;
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}
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else if (CONSTANT_P (XEXP (x, 1)))
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{
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x = gen_rtx_PLUS (mode, XEXP (x, 0), plus_constant (XEXP (x, 1), c));
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c = 0;
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}
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else if (find_constant_term_loc (&y))
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{
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/* We need to be careful since X may be shared and we can't
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modify it in place. */
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rtx copy = copy_rtx (x);
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rtx *const_loc = find_constant_term_loc (©);
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*const_loc = plus_constant (*const_loc, c);
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x = copy;
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c = 0;
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}
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break;
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default:
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break;
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}
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if (c != 0)
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x = gen_rtx_PLUS (mode, x, GEN_INT (c));
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if (GET_CODE (x) == SYMBOL_REF || GET_CODE (x) == LABEL_REF)
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return x;
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else if (all_constant)
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return gen_rtx_CONST (mode, x);
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else
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return x;
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}
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/* If X is a sum, return a new sum like X but lacking any constant terms.
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Add all the removed constant terms into *CONSTPTR.
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X itself is not altered. The result != X if and only if
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it is not isomorphic to X. */
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rtx
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eliminate_constant_term (rtx x, rtx *constptr)
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{
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rtx x0, x1;
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rtx tem;
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if (GET_CODE (x) != PLUS)
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return x;
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/* First handle constants appearing at this level explicitly. */
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if (GET_CODE (XEXP (x, 1)) == CONST_INT
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&& 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x), *constptr,
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XEXP (x, 1)))
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||
&& GET_CODE (tem) == CONST_INT)
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{
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*constptr = tem;
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return eliminate_constant_term (XEXP (x, 0), constptr);
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}
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tem = const0_rtx;
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x0 = eliminate_constant_term (XEXP (x, 0), &tem);
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x1 = eliminate_constant_term (XEXP (x, 1), &tem);
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if ((x1 != XEXP (x, 1) || x0 != XEXP (x, 0))
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&& 0 != (tem = simplify_binary_operation (PLUS, GET_MODE (x),
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*constptr, tem))
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&& GET_CODE (tem) == CONST_INT)
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{
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*constptr = tem;
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return gen_rtx_PLUS (GET_MODE (x), x0, x1);
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||
}
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return x;
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}
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/* Return an rtx for the size in bytes of the value of EXP. */
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rtx
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expr_size (tree exp)
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{
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tree size;
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if (TREE_CODE (exp) == WITH_SIZE_EXPR)
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size = TREE_OPERAND (exp, 1);
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else
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size = SUBSTITUTE_PLACEHOLDER_IN_EXPR (lang_hooks.expr_size (exp), exp);
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return expand_expr (size, NULL_RTX, TYPE_MODE (sizetype), 0);
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}
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/* Return a wide integer for the size in bytes of the value of EXP, or -1
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if the size can vary or is larger than an integer. */
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HOST_WIDE_INT
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int_expr_size (tree exp)
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{
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tree size;
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if (TREE_CODE (exp) == WITH_SIZE_EXPR)
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size = TREE_OPERAND (exp, 1);
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else
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size = lang_hooks.expr_size (exp);
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if (size == 0 || !host_integerp (size, 0))
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return -1;
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return tree_low_cst (size, 0);
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||
}
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/* Return a copy of X in which all memory references
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and all constants that involve symbol refs
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have been replaced with new temporary registers.
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Also emit code to load the memory locations and constants
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into those registers.
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If X contains no such constants or memory references,
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X itself (not a copy) is returned.
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If a constant is found in the address that is not a legitimate constant
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in an insn, it is left alone in the hope that it might be valid in the
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address.
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X may contain no arithmetic except addition, subtraction and multiplication.
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||
Values returned by expand_expr with 1 for sum_ok fit this constraint. */
|
||
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||
static rtx
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break_out_memory_refs (rtx x)
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||
{
|
||
if (MEM_P (x)
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||
|| (CONSTANT_P (x) && CONSTANT_ADDRESS_P (x)
|
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&& GET_MODE (x) != VOIDmode))
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x = force_reg (GET_MODE (x), x);
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else if (GET_CODE (x) == PLUS || GET_CODE (x) == MINUS
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|| GET_CODE (x) == MULT)
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{
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rtx op0 = break_out_memory_refs (XEXP (x, 0));
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rtx op1 = break_out_memory_refs (XEXP (x, 1));
|
||
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if (op0 != XEXP (x, 0) || op1 != XEXP (x, 1))
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x = gen_rtx_fmt_ee (GET_CODE (x), Pmode, op0, op1);
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}
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return x;
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}
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/* Given X, a memory address in ptr_mode, convert it to an address
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in Pmode, or vice versa (TO_MODE says which way). We take advantage of
|
||
the fact that pointers are not allowed to overflow by commuting arithmetic
|
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operations over conversions so that address arithmetic insns can be
|
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used. */
|
||
|
||
rtx
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convert_memory_address (enum machine_mode to_mode ATTRIBUTE_UNUSED,
|
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rtx x)
|
||
{
|
||
#ifndef POINTERS_EXTEND_UNSIGNED
|
||
gcc_assert (GET_MODE (x) == to_mode || GET_MODE (x) == VOIDmode);
|
||
return x;
|
||
#else /* defined(POINTERS_EXTEND_UNSIGNED) */
|
||
enum machine_mode from_mode;
|
||
rtx temp;
|
||
enum rtx_code code;
|
||
|
||
/* If X already has the right mode, just return it. */
|
||
if (GET_MODE (x) == to_mode)
|
||
return x;
|
||
|
||
from_mode = to_mode == ptr_mode ? Pmode : ptr_mode;
|
||
|
||
/* Here we handle some special cases. If none of them apply, fall through
|
||
to the default case. */
|
||
switch (GET_CODE (x))
|
||
{
|
||
case CONST_INT:
|
||
case CONST_DOUBLE:
|
||
if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode))
|
||
code = TRUNCATE;
|
||
else if (POINTERS_EXTEND_UNSIGNED < 0)
|
||
break;
|
||
else if (POINTERS_EXTEND_UNSIGNED > 0)
|
||
code = ZERO_EXTEND;
|
||
else
|
||
code = SIGN_EXTEND;
|
||
temp = simplify_unary_operation (code, to_mode, x, from_mode);
|
||
if (temp)
|
||
return temp;
|
||
break;
|
||
|
||
case SUBREG:
|
||
if ((SUBREG_PROMOTED_VAR_P (x) || REG_POINTER (SUBREG_REG (x)))
|
||
&& GET_MODE (SUBREG_REG (x)) == to_mode)
|
||
return SUBREG_REG (x);
|
||
break;
|
||
|
||
case LABEL_REF:
|
||
temp = gen_rtx_LABEL_REF (to_mode, XEXP (x, 0));
|
||
LABEL_REF_NONLOCAL_P (temp) = LABEL_REF_NONLOCAL_P (x);
|
||
return temp;
|
||
break;
|
||
|
||
case SYMBOL_REF:
|
||
temp = shallow_copy_rtx (x);
|
||
PUT_MODE (temp, to_mode);
|
||
return temp;
|
||
break;
|
||
|
||
case CONST:
|
||
return gen_rtx_CONST (to_mode,
|
||
convert_memory_address (to_mode, XEXP (x, 0)));
|
||
break;
|
||
|
||
case PLUS:
|
||
case MULT:
|
||
/* For addition we can safely permute the conversion and addition
|
||
operation if one operand is a constant and converting the constant
|
||
does not change it. We can always safely permute them if we are
|
||
making the address narrower. */
|
||
if (GET_MODE_SIZE (to_mode) < GET_MODE_SIZE (from_mode)
|
||
|| (GET_CODE (x) == PLUS
|
||
&& GET_CODE (XEXP (x, 1)) == CONST_INT
|
||
&& XEXP (x, 1) == convert_memory_address (to_mode, XEXP (x, 1))))
|
||
return gen_rtx_fmt_ee (GET_CODE (x), to_mode,
|
||
convert_memory_address (to_mode, XEXP (x, 0)),
|
||
XEXP (x, 1));
|
||
break;
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
return convert_modes (to_mode, from_mode,
|
||
x, POINTERS_EXTEND_UNSIGNED);
|
||
#endif /* defined(POINTERS_EXTEND_UNSIGNED) */
|
||
}
|
||
|
||
/* Return something equivalent to X but valid as a memory address
|
||
for something of mode MODE. When X is not itself valid, this
|
||
works by copying X or subexpressions of it into registers. */
|
||
|
||
rtx
|
||
memory_address (enum machine_mode mode, rtx x)
|
||
{
|
||
rtx oldx = x;
|
||
|
||
x = convert_memory_address (Pmode, x);
|
||
|
||
/* By passing constant addresses through registers
|
||
we get a chance to cse them. */
|
||
if (! cse_not_expected && CONSTANT_P (x) && CONSTANT_ADDRESS_P (x))
|
||
x = force_reg (Pmode, x);
|
||
|
||
/* We get better cse by rejecting indirect addressing at this stage.
|
||
Let the combiner create indirect addresses where appropriate.
|
||
For now, generate the code so that the subexpressions useful to share
|
||
are visible. But not if cse won't be done! */
|
||
else
|
||
{
|
||
if (! cse_not_expected && !REG_P (x))
|
||
x = break_out_memory_refs (x);
|
||
|
||
/* At this point, any valid address is accepted. */
|
||
if (memory_address_p (mode, x))
|
||
goto win;
|
||
|
||
/* If it was valid before but breaking out memory refs invalidated it,
|
||
use it the old way. */
|
||
if (memory_address_p (mode, oldx))
|
||
goto win2;
|
||
|
||
/* Perform machine-dependent transformations on X
|
||
in certain cases. This is not necessary since the code
|
||
below can handle all possible cases, but machine-dependent
|
||
transformations can make better code. */
|
||
LEGITIMIZE_ADDRESS (x, oldx, mode, win);
|
||
|
||
/* PLUS and MULT can appear in special ways
|
||
as the result of attempts to make an address usable for indexing.
|
||
Usually they are dealt with by calling force_operand, below.
|
||
But a sum containing constant terms is special
|
||
if removing them makes the sum a valid address:
|
||
then we generate that address in a register
|
||
and index off of it. We do this because it often makes
|
||
shorter code, and because the addresses thus generated
|
||
in registers often become common subexpressions. */
|
||
if (GET_CODE (x) == PLUS)
|
||
{
|
||
rtx constant_term = const0_rtx;
|
||
rtx y = eliminate_constant_term (x, &constant_term);
|
||
if (constant_term == const0_rtx
|
||
|| ! memory_address_p (mode, y))
|
||
x = force_operand (x, NULL_RTX);
|
||
else
|
||
{
|
||
y = gen_rtx_PLUS (GET_MODE (x), copy_to_reg (y), constant_term);
|
||
if (! memory_address_p (mode, y))
|
||
x = force_operand (x, NULL_RTX);
|
||
else
|
||
x = y;
|
||
}
|
||
}
|
||
|
||
else if (GET_CODE (x) == MULT || GET_CODE (x) == MINUS)
|
||
x = force_operand (x, NULL_RTX);
|
||
|
||
/* If we have a register that's an invalid address,
|
||
it must be a hard reg of the wrong class. Copy it to a pseudo. */
|
||
else if (REG_P (x))
|
||
x = copy_to_reg (x);
|
||
|
||
/* Last resort: copy the value to a register, since
|
||
the register is a valid address. */
|
||
else
|
||
x = force_reg (Pmode, x);
|
||
|
||
goto done;
|
||
|
||
win2:
|
||
x = oldx;
|
||
win:
|
||
if (flag_force_addr && ! cse_not_expected && !REG_P (x))
|
||
{
|
||
x = force_operand (x, NULL_RTX);
|
||
x = force_reg (Pmode, x);
|
||
}
|
||
}
|
||
|
||
done:
|
||
|
||
/* If we didn't change the address, we are done. Otherwise, mark
|
||
a reg as a pointer if we have REG or REG + CONST_INT. */
|
||
if (oldx == x)
|
||
return x;
|
||
else if (REG_P (x))
|
||
mark_reg_pointer (x, BITS_PER_UNIT);
|
||
else if (GET_CODE (x) == PLUS
|
||
&& REG_P (XEXP (x, 0))
|
||
&& GET_CODE (XEXP (x, 1)) == CONST_INT)
|
||
mark_reg_pointer (XEXP (x, 0), BITS_PER_UNIT);
|
||
|
||
/* OLDX may have been the address on a temporary. Update the address
|
||
to indicate that X is now used. */
|
||
update_temp_slot_address (oldx, x);
|
||
|
||
return x;
|
||
}
|
||
|
||
/* Like `memory_address' but pretend `flag_force_addr' is 0. */
|
||
|
||
rtx
|
||
memory_address_noforce (enum machine_mode mode, rtx x)
|
||
{
|
||
int ambient_force_addr = flag_force_addr;
|
||
rtx val;
|
||
|
||
flag_force_addr = 0;
|
||
val = memory_address (mode, x);
|
||
flag_force_addr = ambient_force_addr;
|
||
return val;
|
||
}
|
||
|
||
/* Convert a mem ref into one with a valid memory address.
|
||
Pass through anything else unchanged. */
|
||
|
||
rtx
|
||
validize_mem (rtx ref)
|
||
{
|
||
if (!MEM_P (ref))
|
||
return ref;
|
||
ref = use_anchored_address (ref);
|
||
if (! (flag_force_addr && CONSTANT_ADDRESS_P (XEXP (ref, 0)))
|
||
&& memory_address_p (GET_MODE (ref), XEXP (ref, 0)))
|
||
return ref;
|
||
|
||
/* Don't alter REF itself, since that is probably a stack slot. */
|
||
return replace_equiv_address (ref, XEXP (ref, 0));
|
||
}
|
||
|
||
/* If X is a memory reference to a member of an object block, try rewriting
|
||
it to use an anchor instead. Return the new memory reference on success
|
||
and the old one on failure. */
|
||
|
||
rtx
|
||
use_anchored_address (rtx x)
|
||
{
|
||
rtx base;
|
||
HOST_WIDE_INT offset;
|
||
|
||
if (!flag_section_anchors)
|
||
return x;
|
||
|
||
if (!MEM_P (x))
|
||
return x;
|
||
|
||
/* Split the address into a base and offset. */
|
||
base = XEXP (x, 0);
|
||
offset = 0;
|
||
if (GET_CODE (base) == CONST
|
||
&& GET_CODE (XEXP (base, 0)) == PLUS
|
||
&& GET_CODE (XEXP (XEXP (base, 0), 1)) == CONST_INT)
|
||
{
|
||
offset += INTVAL (XEXP (XEXP (base, 0), 1));
|
||
base = XEXP (XEXP (base, 0), 0);
|
||
}
|
||
|
||
/* Check whether BASE is suitable for anchors. */
|
||
if (GET_CODE (base) != SYMBOL_REF
|
||
|| !SYMBOL_REF_HAS_BLOCK_INFO_P (base)
|
||
|| SYMBOL_REF_ANCHOR_P (base)
|
||
|| SYMBOL_REF_BLOCK (base) == NULL
|
||
|| !targetm.use_anchors_for_symbol_p (base))
|
||
return x;
|
||
|
||
/* Decide where BASE is going to be. */
|
||
place_block_symbol (base);
|
||
|
||
/* Get the anchor we need to use. */
|
||
offset += SYMBOL_REF_BLOCK_OFFSET (base);
|
||
base = get_section_anchor (SYMBOL_REF_BLOCK (base), offset,
|
||
SYMBOL_REF_TLS_MODEL (base));
|
||
|
||
/* Work out the offset from the anchor. */
|
||
offset -= SYMBOL_REF_BLOCK_OFFSET (base);
|
||
|
||
/* If we're going to run a CSE pass, force the anchor into a register.
|
||
We will then be able to reuse registers for several accesses, if the
|
||
target costs say that that's worthwhile. */
|
||
if (!cse_not_expected)
|
||
base = force_reg (GET_MODE (base), base);
|
||
|
||
return replace_equiv_address (x, plus_constant (base, offset));
|
||
}
|
||
|
||
/* Copy the value or contents of X to a new temp reg and return that reg. */
|
||
|
||
rtx
|
||
copy_to_reg (rtx x)
|
||
{
|
||
rtx temp = gen_reg_rtx (GET_MODE (x));
|
||
|
||
/* If not an operand, must be an address with PLUS and MULT so
|
||
do the computation. */
|
||
if (! general_operand (x, VOIDmode))
|
||
x = force_operand (x, temp);
|
||
|
||
if (x != temp)
|
||
emit_move_insn (temp, x);
|
||
|
||
return temp;
|
||
}
|
||
|
||
/* Like copy_to_reg but always give the new register mode Pmode
|
||
in case X is a constant. */
|
||
|
||
rtx
|
||
copy_addr_to_reg (rtx x)
|
||
{
|
||
return copy_to_mode_reg (Pmode, x);
|
||
}
|
||
|
||
/* Like copy_to_reg but always give the new register mode MODE
|
||
in case X is a constant. */
|
||
|
||
rtx
|
||
copy_to_mode_reg (enum machine_mode mode, rtx x)
|
||
{
|
||
rtx temp = gen_reg_rtx (mode);
|
||
|
||
/* If not an operand, must be an address with PLUS and MULT so
|
||
do the computation. */
|
||
if (! general_operand (x, VOIDmode))
|
||
x = force_operand (x, temp);
|
||
|
||
gcc_assert (GET_MODE (x) == mode || GET_MODE (x) == VOIDmode);
|
||
if (x != temp)
|
||
emit_move_insn (temp, x);
|
||
return temp;
|
||
}
|
||
|
||
/* Load X into a register if it is not already one.
|
||
Use mode MODE for the register.
|
||
X should be valid for mode MODE, but it may be a constant which
|
||
is valid for all integer modes; that's why caller must specify MODE.
|
||
|
||
The caller must not alter the value in the register we return,
|
||
since we mark it as a "constant" register. */
|
||
|
||
rtx
|
||
force_reg (enum machine_mode mode, rtx x)
|
||
{
|
||
rtx temp, insn, set;
|
||
|
||
if (REG_P (x))
|
||
return x;
|
||
|
||
if (general_operand (x, mode))
|
||
{
|
||
temp = gen_reg_rtx (mode);
|
||
insn = emit_move_insn (temp, x);
|
||
}
|
||
else
|
||
{
|
||
temp = force_operand (x, NULL_RTX);
|
||
if (REG_P (temp))
|
||
insn = get_last_insn ();
|
||
else
|
||
{
|
||
rtx temp2 = gen_reg_rtx (mode);
|
||
insn = emit_move_insn (temp2, temp);
|
||
temp = temp2;
|
||
}
|
||
}
|
||
|
||
/* Let optimizers know that TEMP's value never changes
|
||
and that X can be substituted for it. Don't get confused
|
||
if INSN set something else (such as a SUBREG of TEMP). */
|
||
if (CONSTANT_P (x)
|
||
&& (set = single_set (insn)) != 0
|
||
&& SET_DEST (set) == temp
|
||
&& ! rtx_equal_p (x, SET_SRC (set)))
|
||
set_unique_reg_note (insn, REG_EQUAL, x);
|
||
|
||
/* Let optimizers know that TEMP is a pointer, and if so, the
|
||
known alignment of that pointer. */
|
||
{
|
||
unsigned align = 0;
|
||
if (GET_CODE (x) == SYMBOL_REF)
|
||
{
|
||
align = BITS_PER_UNIT;
|
||
if (SYMBOL_REF_DECL (x) && DECL_P (SYMBOL_REF_DECL (x)))
|
||
align = DECL_ALIGN (SYMBOL_REF_DECL (x));
|
||
}
|
||
else if (GET_CODE (x) == LABEL_REF)
|
||
align = BITS_PER_UNIT;
|
||
else if (GET_CODE (x) == CONST
|
||
&& GET_CODE (XEXP (x, 0)) == PLUS
|
||
&& GET_CODE (XEXP (XEXP (x, 0), 0)) == SYMBOL_REF
|
||
&& GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
|
||
{
|
||
rtx s = XEXP (XEXP (x, 0), 0);
|
||
rtx c = XEXP (XEXP (x, 0), 1);
|
||
unsigned sa, ca;
|
||
|
||
sa = BITS_PER_UNIT;
|
||
if (SYMBOL_REF_DECL (s) && DECL_P (SYMBOL_REF_DECL (s)))
|
||
sa = DECL_ALIGN (SYMBOL_REF_DECL (s));
|
||
|
||
ca = exact_log2 (INTVAL (c) & -INTVAL (c)) * BITS_PER_UNIT;
|
||
|
||
align = MIN (sa, ca);
|
||
}
|
||
else if (MEM_P (x) && MEM_POINTER (x))
|
||
align = MEM_ALIGN (x);
|
||
|
||
if (align)
|
||
mark_reg_pointer (temp, align);
|
||
}
|
||
|
||
return temp;
|
||
}
|
||
|
||
/* If X is a memory ref, copy its contents to a new temp reg and return
|
||
that reg. Otherwise, return X. */
|
||
|
||
rtx
|
||
force_not_mem (rtx x)
|
||
{
|
||
rtx temp;
|
||
|
||
if (!MEM_P (x) || GET_MODE (x) == BLKmode)
|
||
return x;
|
||
|
||
temp = gen_reg_rtx (GET_MODE (x));
|
||
|
||
if (MEM_POINTER (x))
|
||
REG_POINTER (temp) = 1;
|
||
|
||
emit_move_insn (temp, x);
|
||
return temp;
|
||
}
|
||
|
||
/* Copy X to TARGET (if it's nonzero and a reg)
|
||
or to a new temp reg and return that reg.
|
||
MODE is the mode to use for X in case it is a constant. */
|
||
|
||
rtx
|
||
copy_to_suggested_reg (rtx x, rtx target, enum machine_mode mode)
|
||
{
|
||
rtx temp;
|
||
|
||
if (target && REG_P (target))
|
||
temp = target;
|
||
else
|
||
temp = gen_reg_rtx (mode);
|
||
|
||
emit_move_insn (temp, x);
|
||
return temp;
|
||
}
|
||
|
||
/* Return the mode to use to store a scalar of TYPE and MODE.
|
||
PUNSIGNEDP points to the signedness of the type and may be adjusted
|
||
to show what signedness to use on extension operations.
|
||
|
||
FOR_CALL is nonzero if this call is promoting args for a call. */
|
||
|
||
#if defined(PROMOTE_MODE) && !defined(PROMOTE_FUNCTION_MODE)
|
||
#define PROMOTE_FUNCTION_MODE PROMOTE_MODE
|
||
#endif
|
||
|
||
enum machine_mode
|
||
promote_mode (tree type, enum machine_mode mode, int *punsignedp,
|
||
int for_call ATTRIBUTE_UNUSED)
|
||
{
|
||
enum tree_code code = TREE_CODE (type);
|
||
int unsignedp = *punsignedp;
|
||
|
||
#ifndef PROMOTE_MODE
|
||
if (! for_call)
|
||
return mode;
|
||
#endif
|
||
|
||
switch (code)
|
||
{
|
||
#ifdef PROMOTE_FUNCTION_MODE
|
||
case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
|
||
case REAL_TYPE: case OFFSET_TYPE:
|
||
#ifdef PROMOTE_MODE
|
||
if (for_call)
|
||
{
|
||
#endif
|
||
PROMOTE_FUNCTION_MODE (mode, unsignedp, type);
|
||
#ifdef PROMOTE_MODE
|
||
}
|
||
else
|
||
{
|
||
PROMOTE_MODE (mode, unsignedp, type);
|
||
}
|
||
#endif
|
||
break;
|
||
#endif
|
||
|
||
#ifdef POINTERS_EXTEND_UNSIGNED
|
||
case REFERENCE_TYPE:
|
||
case POINTER_TYPE:
|
||
mode = Pmode;
|
||
unsignedp = POINTERS_EXTEND_UNSIGNED;
|
||
break;
|
||
#endif
|
||
|
||
default:
|
||
break;
|
||
}
|
||
|
||
*punsignedp = unsignedp;
|
||
return mode;
|
||
}
|
||
|
||
/* Adjust the stack pointer by ADJUST (an rtx for a number of bytes).
|
||
This pops when ADJUST is positive. ADJUST need not be constant. */
|
||
|
||
void
|
||
adjust_stack (rtx adjust)
|
||
{
|
||
rtx temp;
|
||
|
||
if (adjust == const0_rtx)
|
||
return;
|
||
|
||
/* We expect all variable sized adjustments to be multiple of
|
||
PREFERRED_STACK_BOUNDARY. */
|
||
if (GET_CODE (adjust) == CONST_INT)
|
||
stack_pointer_delta -= INTVAL (adjust);
|
||
|
||
temp = expand_binop (Pmode,
|
||
#ifdef STACK_GROWS_DOWNWARD
|
||
add_optab,
|
||
#else
|
||
sub_optab,
|
||
#endif
|
||
stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
|
||
OPTAB_LIB_WIDEN);
|
||
|
||
if (temp != stack_pointer_rtx)
|
||
emit_move_insn (stack_pointer_rtx, temp);
|
||
}
|
||
|
||
/* Adjust the stack pointer by minus ADJUST (an rtx for a number of bytes).
|
||
This pushes when ADJUST is positive. ADJUST need not be constant. */
|
||
|
||
void
|
||
anti_adjust_stack (rtx adjust)
|
||
{
|
||
rtx temp;
|
||
|
||
if (adjust == const0_rtx)
|
||
return;
|
||
|
||
/* We expect all variable sized adjustments to be multiple of
|
||
PREFERRED_STACK_BOUNDARY. */
|
||
if (GET_CODE (adjust) == CONST_INT)
|
||
stack_pointer_delta += INTVAL (adjust);
|
||
|
||
temp = expand_binop (Pmode,
|
||
#ifdef STACK_GROWS_DOWNWARD
|
||
sub_optab,
|
||
#else
|
||
add_optab,
|
||
#endif
|
||
stack_pointer_rtx, adjust, stack_pointer_rtx, 0,
|
||
OPTAB_LIB_WIDEN);
|
||
|
||
if (temp != stack_pointer_rtx)
|
||
emit_move_insn (stack_pointer_rtx, temp);
|
||
}
|
||
|
||
/* Round the size of a block to be pushed up to the boundary required
|
||
by this machine. SIZE is the desired size, which need not be constant. */
|
||
|
||
static rtx
|
||
round_push (rtx size)
|
||
{
|
||
int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
|
||
|
||
if (align == 1)
|
||
return size;
|
||
|
||
if (GET_CODE (size) == CONST_INT)
|
||
{
|
||
HOST_WIDE_INT new = (INTVAL (size) + align - 1) / align * align;
|
||
|
||
if (INTVAL (size) != new)
|
||
size = GEN_INT (new);
|
||
}
|
||
else
|
||
{
|
||
/* CEIL_DIV_EXPR needs to worry about the addition overflowing,
|
||
but we know it can't. So add ourselves and then do
|
||
TRUNC_DIV_EXPR. */
|
||
size = expand_binop (Pmode, add_optab, size, GEN_INT (align - 1),
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size, GEN_INT (align),
|
||
NULL_RTX, 1);
|
||
size = expand_mult (Pmode, size, GEN_INT (align), NULL_RTX, 1);
|
||
}
|
||
|
||
return size;
|
||
}
|
||
|
||
/* Save the stack pointer for the purpose in SAVE_LEVEL. PSAVE is a pointer
|
||
to a previously-created save area. If no save area has been allocated,
|
||
this function will allocate one. If a save area is specified, it
|
||
must be of the proper mode.
|
||
|
||
The insns are emitted after insn AFTER, if nonzero, otherwise the insns
|
||
are emitted at the current position. */
|
||
|
||
void
|
||
emit_stack_save (enum save_level save_level, rtx *psave, rtx after)
|
||
{
|
||
rtx sa = *psave;
|
||
/* The default is that we use a move insn and save in a Pmode object. */
|
||
rtx (*fcn) (rtx, rtx) = gen_move_insn;
|
||
enum machine_mode mode = STACK_SAVEAREA_MODE (save_level);
|
||
|
||
/* See if this machine has anything special to do for this kind of save. */
|
||
switch (save_level)
|
||
{
|
||
#ifdef HAVE_save_stack_block
|
||
case SAVE_BLOCK:
|
||
if (HAVE_save_stack_block)
|
||
fcn = gen_save_stack_block;
|
||
break;
|
||
#endif
|
||
#ifdef HAVE_save_stack_function
|
||
case SAVE_FUNCTION:
|
||
if (HAVE_save_stack_function)
|
||
fcn = gen_save_stack_function;
|
||
break;
|
||
#endif
|
||
#ifdef HAVE_save_stack_nonlocal
|
||
case SAVE_NONLOCAL:
|
||
if (HAVE_save_stack_nonlocal)
|
||
fcn = gen_save_stack_nonlocal;
|
||
break;
|
||
#endif
|
||
default:
|
||
break;
|
||
}
|
||
|
||
/* If there is no save area and we have to allocate one, do so. Otherwise
|
||
verify the save area is the proper mode. */
|
||
|
||
if (sa == 0)
|
||
{
|
||
if (mode != VOIDmode)
|
||
{
|
||
if (save_level == SAVE_NONLOCAL)
|
||
*psave = sa = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
|
||
else
|
||
*psave = sa = gen_reg_rtx (mode);
|
||
}
|
||
}
|
||
|
||
if (after)
|
||
{
|
||
rtx seq;
|
||
|
||
start_sequence ();
|
||
do_pending_stack_adjust ();
|
||
/* We must validize inside the sequence, to ensure that any instructions
|
||
created by the validize call also get moved to the right place. */
|
||
if (sa != 0)
|
||
sa = validize_mem (sa);
|
||
emit_insn (fcn (sa, stack_pointer_rtx));
|
||
seq = get_insns ();
|
||
end_sequence ();
|
||
emit_insn_after (seq, after);
|
||
}
|
||
else
|
||
{
|
||
do_pending_stack_adjust ();
|
||
if (sa != 0)
|
||
sa = validize_mem (sa);
|
||
emit_insn (fcn (sa, stack_pointer_rtx));
|
||
}
|
||
}
|
||
|
||
/* Restore the stack pointer for the purpose in SAVE_LEVEL. SA is the save
|
||
area made by emit_stack_save. If it is zero, we have nothing to do.
|
||
|
||
Put any emitted insns after insn AFTER, if nonzero, otherwise at
|
||
current position. */
|
||
|
||
void
|
||
emit_stack_restore (enum save_level save_level, rtx sa, rtx after)
|
||
{
|
||
/* The default is that we use a move insn. */
|
||
rtx (*fcn) (rtx, rtx) = gen_move_insn;
|
||
|
||
/* See if this machine has anything special to do for this kind of save. */
|
||
switch (save_level)
|
||
{
|
||
#ifdef HAVE_restore_stack_block
|
||
case SAVE_BLOCK:
|
||
if (HAVE_restore_stack_block)
|
||
fcn = gen_restore_stack_block;
|
||
break;
|
||
#endif
|
||
#ifdef HAVE_restore_stack_function
|
||
case SAVE_FUNCTION:
|
||
if (HAVE_restore_stack_function)
|
||
fcn = gen_restore_stack_function;
|
||
break;
|
||
#endif
|
||
#ifdef HAVE_restore_stack_nonlocal
|
||
case SAVE_NONLOCAL:
|
||
if (HAVE_restore_stack_nonlocal)
|
||
fcn = gen_restore_stack_nonlocal;
|
||
break;
|
||
#endif
|
||
default:
|
||
break;
|
||
}
|
||
|
||
if (sa != 0)
|
||
{
|
||
sa = validize_mem (sa);
|
||
/* These clobbers prevent the scheduler from moving
|
||
references to variable arrays below the code
|
||
that deletes (pops) the arrays. */
|
||
emit_insn (gen_rtx_CLOBBER (VOIDmode,
|
||
gen_rtx_MEM (BLKmode,
|
||
gen_rtx_SCRATCH (VOIDmode))));
|
||
emit_insn (gen_rtx_CLOBBER (VOIDmode,
|
||
gen_rtx_MEM (BLKmode, stack_pointer_rtx)));
|
||
}
|
||
|
||
discard_pending_stack_adjust ();
|
||
|
||
if (after)
|
||
{
|
||
rtx seq;
|
||
|
||
start_sequence ();
|
||
emit_insn (fcn (stack_pointer_rtx, sa));
|
||
seq = get_insns ();
|
||
end_sequence ();
|
||
emit_insn_after (seq, after);
|
||
}
|
||
else
|
||
emit_insn (fcn (stack_pointer_rtx, sa));
|
||
}
|
||
|
||
/* Invoke emit_stack_save on the nonlocal_goto_save_area for the current
|
||
function. This function should be called whenever we allocate or
|
||
deallocate dynamic stack space. */
|
||
|
||
void
|
||
update_nonlocal_goto_save_area (void)
|
||
{
|
||
tree t_save;
|
||
rtx r_save;
|
||
|
||
/* The nonlocal_goto_save_area object is an array of N pointers. The
|
||
first one is used for the frame pointer save; the rest are sized by
|
||
STACK_SAVEAREA_MODE. Create a reference to array index 1, the first
|
||
of the stack save area slots. */
|
||
t_save = build4 (ARRAY_REF, ptr_type_node, cfun->nonlocal_goto_save_area,
|
||
integer_one_node, NULL_TREE, NULL_TREE);
|
||
r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
|
||
|
||
emit_stack_save (SAVE_NONLOCAL, &r_save, NULL_RTX);
|
||
}
|
||
|
||
/* Return an rtx representing the address of an area of memory dynamically
|
||
pushed on the stack. This region of memory is always aligned to
|
||
a multiple of BIGGEST_ALIGNMENT.
|
||
|
||
Any required stack pointer alignment is preserved.
|
||
|
||
SIZE is an rtx representing the size of the area.
|
||
TARGET is a place in which the address can be placed.
|
||
|
||
KNOWN_ALIGN is the alignment (in bits) that we know SIZE has. */
|
||
|
||
rtx
|
||
allocate_dynamic_stack_space (rtx size, rtx target, int known_align)
|
||
{
|
||
/* If we're asking for zero bytes, it doesn't matter what we point
|
||
to since we can't dereference it. But return a reasonable
|
||
address anyway. */
|
||
if (size == const0_rtx)
|
||
return virtual_stack_dynamic_rtx;
|
||
|
||
/* Otherwise, show we're calling alloca or equivalent. */
|
||
current_function_calls_alloca = 1;
|
||
|
||
/* Ensure the size is in the proper mode. */
|
||
if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
|
||
size = convert_to_mode (Pmode, size, 1);
|
||
|
||
/* We can't attempt to minimize alignment necessary, because we don't
|
||
know the final value of preferred_stack_boundary yet while executing
|
||
this code. */
|
||
cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
|
||
|
||
/* We will need to ensure that the address we return is aligned to
|
||
BIGGEST_ALIGNMENT. If STACK_DYNAMIC_OFFSET is defined, we don't
|
||
always know its final value at this point in the compilation (it
|
||
might depend on the size of the outgoing parameter lists, for
|
||
example), so we must align the value to be returned in that case.
|
||
(Note that STACK_DYNAMIC_OFFSET will have a default nonzero value if
|
||
STACK_POINTER_OFFSET or ACCUMULATE_OUTGOING_ARGS are defined).
|
||
We must also do an alignment operation on the returned value if
|
||
the stack pointer alignment is less strict that BIGGEST_ALIGNMENT.
|
||
|
||
If we have to align, we must leave space in SIZE for the hole
|
||
that might result from the alignment operation. */
|
||
|
||
#if defined (STACK_DYNAMIC_OFFSET) || defined (STACK_POINTER_OFFSET)
|
||
#define MUST_ALIGN 1
|
||
#else
|
||
#define MUST_ALIGN (PREFERRED_STACK_BOUNDARY < BIGGEST_ALIGNMENT)
|
||
#endif
|
||
|
||
if (MUST_ALIGN)
|
||
size
|
||
= force_operand (plus_constant (size,
|
||
BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
|
||
NULL_RTX);
|
||
|
||
#ifdef SETJMP_VIA_SAVE_AREA
|
||
/* If setjmp restores regs from a save area in the stack frame,
|
||
avoid clobbering the reg save area. Note that the offset of
|
||
virtual_incoming_args_rtx includes the preallocated stack args space.
|
||
It would be no problem to clobber that, but it's on the wrong side
|
||
of the old save area.
|
||
|
||
What used to happen is that, since we did not know for sure
|
||
whether setjmp() was invoked until after RTL generation, we
|
||
would use reg notes to store the "optimized" size and fix things
|
||
up later. These days we know this information before we ever
|
||
start building RTL so the reg notes are unnecessary. */
|
||
if (!current_function_calls_setjmp)
|
||
{
|
||
int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
|
||
|
||
/* ??? Code below assumes that the save area needs maximal
|
||
alignment. This constraint may be too strong. */
|
||
gcc_assert (PREFERRED_STACK_BOUNDARY == BIGGEST_ALIGNMENT);
|
||
|
||
if (GET_CODE (size) == CONST_INT)
|
||
{
|
||
HOST_WIDE_INT new = INTVAL (size) / align * align;
|
||
|
||
if (INTVAL (size) != new)
|
||
size = GEN_INT (new);
|
||
}
|
||
else
|
||
{
|
||
/* Since we know overflow is not possible, we avoid using
|
||
CEIL_DIV_EXPR and use TRUNC_DIV_EXPR instead. */
|
||
size = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, size,
|
||
GEN_INT (align), NULL_RTX, 1);
|
||
size = expand_mult (Pmode, size,
|
||
GEN_INT (align), NULL_RTX, 1);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
rtx dynamic_offset
|
||
= expand_binop (Pmode, sub_optab, virtual_stack_dynamic_rtx,
|
||
stack_pointer_rtx, NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
|
||
size = expand_binop (Pmode, add_optab, size, dynamic_offset,
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
}
|
||
#endif /* SETJMP_VIA_SAVE_AREA */
|
||
|
||
/* Round the size to a multiple of the required stack alignment.
|
||
Since the stack if presumed to be rounded before this allocation,
|
||
this will maintain the required alignment.
|
||
|
||
If the stack grows downward, we could save an insn by subtracting
|
||
SIZE from the stack pointer and then aligning the stack pointer.
|
||
The problem with this is that the stack pointer may be unaligned
|
||
between the execution of the subtraction and alignment insns and
|
||
some machines do not allow this. Even on those that do, some
|
||
signal handlers malfunction if a signal should occur between those
|
||
insns. Since this is an extremely rare event, we have no reliable
|
||
way of knowing which systems have this problem. So we avoid even
|
||
momentarily mis-aligning the stack. */
|
||
|
||
/* If we added a variable amount to SIZE,
|
||
we can no longer assume it is aligned. */
|
||
#if !defined (SETJMP_VIA_SAVE_AREA)
|
||
if (MUST_ALIGN || known_align % PREFERRED_STACK_BOUNDARY != 0)
|
||
#endif
|
||
size = round_push (size);
|
||
|
||
do_pending_stack_adjust ();
|
||
|
||
/* We ought to be called always on the toplevel and stack ought to be aligned
|
||
properly. */
|
||
gcc_assert (!(stack_pointer_delta
|
||
% (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)));
|
||
|
||
/* If needed, check that we have the required amount of stack. Take into
|
||
account what has already been checked. */
|
||
if (flag_stack_check && ! STACK_CHECK_BUILTIN)
|
||
probe_stack_range (STACK_CHECK_MAX_FRAME_SIZE + STACK_CHECK_PROTECT, size);
|
||
|
||
/* Don't use a TARGET that isn't a pseudo or is the wrong mode. */
|
||
if (target == 0 || !REG_P (target)
|
||
|| REGNO (target) < FIRST_PSEUDO_REGISTER
|
||
|| GET_MODE (target) != Pmode)
|
||
target = gen_reg_rtx (Pmode);
|
||
|
||
mark_reg_pointer (target, known_align);
|
||
|
||
/* Perform the required allocation from the stack. Some systems do
|
||
this differently than simply incrementing/decrementing from the
|
||
stack pointer, such as acquiring the space by calling malloc(). */
|
||
#ifdef HAVE_allocate_stack
|
||
if (HAVE_allocate_stack)
|
||
{
|
||
enum machine_mode mode = STACK_SIZE_MODE;
|
||
insn_operand_predicate_fn pred;
|
||
|
||
/* We don't have to check against the predicate for operand 0 since
|
||
TARGET is known to be a pseudo of the proper mode, which must
|
||
be valid for the operand. For operand 1, convert to the
|
||
proper mode and validate. */
|
||
if (mode == VOIDmode)
|
||
mode = insn_data[(int) CODE_FOR_allocate_stack].operand[1].mode;
|
||
|
||
pred = insn_data[(int) CODE_FOR_allocate_stack].operand[1].predicate;
|
||
if (pred && ! ((*pred) (size, mode)))
|
||
size = copy_to_mode_reg (mode, convert_to_mode (mode, size, 1));
|
||
|
||
emit_insn (gen_allocate_stack (target, size));
|
||
}
|
||
else
|
||
#endif
|
||
{
|
||
#ifndef STACK_GROWS_DOWNWARD
|
||
emit_move_insn (target, virtual_stack_dynamic_rtx);
|
||
#endif
|
||
|
||
/* Check stack bounds if necessary. */
|
||
if (current_function_limit_stack)
|
||
{
|
||
rtx available;
|
||
rtx space_available = gen_label_rtx ();
|
||
#ifdef STACK_GROWS_DOWNWARD
|
||
available = expand_binop (Pmode, sub_optab,
|
||
stack_pointer_rtx, stack_limit_rtx,
|
||
NULL_RTX, 1, OPTAB_WIDEN);
|
||
#else
|
||
available = expand_binop (Pmode, sub_optab,
|
||
stack_limit_rtx, stack_pointer_rtx,
|
||
NULL_RTX, 1, OPTAB_WIDEN);
|
||
#endif
|
||
emit_cmp_and_jump_insns (available, size, GEU, NULL_RTX, Pmode, 1,
|
||
space_available);
|
||
#ifdef HAVE_trap
|
||
if (HAVE_trap)
|
||
emit_insn (gen_trap ());
|
||
else
|
||
#endif
|
||
error ("stack limits not supported on this target");
|
||
emit_barrier ();
|
||
emit_label (space_available);
|
||
}
|
||
|
||
anti_adjust_stack (size);
|
||
|
||
#ifdef STACK_GROWS_DOWNWARD
|
||
emit_move_insn (target, virtual_stack_dynamic_rtx);
|
||
#endif
|
||
}
|
||
|
||
if (MUST_ALIGN)
|
||
{
|
||
/* CEIL_DIV_EXPR needs to worry about the addition overflowing,
|
||
but we know it can't. So add ourselves and then do
|
||
TRUNC_DIV_EXPR. */
|
||
target = expand_binop (Pmode, add_optab, target,
|
||
GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT - 1),
|
||
NULL_RTX, 1, OPTAB_LIB_WIDEN);
|
||
target = expand_divmod (0, TRUNC_DIV_EXPR, Pmode, target,
|
||
GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
|
||
NULL_RTX, 1);
|
||
target = expand_mult (Pmode, target,
|
||
GEN_INT (BIGGEST_ALIGNMENT / BITS_PER_UNIT),
|
||
NULL_RTX, 1);
|
||
}
|
||
|
||
/* Record the new stack level for nonlocal gotos. */
|
||
if (cfun->nonlocal_goto_save_area != 0)
|
||
update_nonlocal_goto_save_area ();
|
||
|
||
return target;
|
||
}
|
||
|
||
/* A front end may want to override GCC's stack checking by providing a
|
||
run-time routine to call to check the stack, so provide a mechanism for
|
||
calling that routine. */
|
||
|
||
static GTY(()) rtx stack_check_libfunc;
|
||
|
||
void
|
||
set_stack_check_libfunc (rtx libfunc)
|
||
{
|
||
stack_check_libfunc = libfunc;
|
||
}
|
||
|
||
/* Emit one stack probe at ADDRESS, an address within the stack. */
|
||
|
||
static void
|
||
emit_stack_probe (rtx address)
|
||
{
|
||
rtx memref = gen_rtx_MEM (word_mode, address);
|
||
|
||
MEM_VOLATILE_P (memref) = 1;
|
||
|
||
if (STACK_CHECK_PROBE_LOAD)
|
||
emit_move_insn (gen_reg_rtx (word_mode), memref);
|
||
else
|
||
emit_move_insn (memref, const0_rtx);
|
||
}
|
||
|
||
/* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
|
||
FIRST is a constant and size is a Pmode RTX. These are offsets from the
|
||
current stack pointer. STACK_GROWS_DOWNWARD says whether to add or
|
||
subtract from the stack. If SIZE is constant, this is done
|
||
with a fixed number of probes. Otherwise, we must make a loop. */
|
||
|
||
#ifdef STACK_GROWS_DOWNWARD
|
||
#define STACK_GROW_OP MINUS
|
||
#else
|
||
#define STACK_GROW_OP PLUS
|
||
#endif
|
||
|
||
void
|
||
probe_stack_range (HOST_WIDE_INT first, rtx size)
|
||
{
|
||
/* First ensure SIZE is Pmode. */
|
||
if (GET_MODE (size) != VOIDmode && GET_MODE (size) != Pmode)
|
||
size = convert_to_mode (Pmode, size, 1);
|
||
|
||
/* Next see if the front end has set up a function for us to call to
|
||
check the stack. */
|
||
if (stack_check_libfunc != 0)
|
||
{
|
||
rtx addr = memory_address (QImode,
|
||
gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
|
||
stack_pointer_rtx,
|
||
plus_constant (size, first)));
|
||
|
||
addr = convert_memory_address (ptr_mode, addr);
|
||
emit_library_call (stack_check_libfunc, LCT_NORMAL, VOIDmode, 1, addr,
|
||
ptr_mode);
|
||
}
|
||
|
||
/* Next see if we have an insn to check the stack. Use it if so. */
|
||
#ifdef HAVE_check_stack
|
||
else if (HAVE_check_stack)
|
||
{
|
||
insn_operand_predicate_fn pred;
|
||
rtx last_addr
|
||
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
|
||
stack_pointer_rtx,
|
||
plus_constant (size, first)),
|
||
NULL_RTX);
|
||
|
||
pred = insn_data[(int) CODE_FOR_check_stack].operand[0].predicate;
|
||
if (pred && ! ((*pred) (last_addr, Pmode)))
|
||
last_addr = copy_to_mode_reg (Pmode, last_addr);
|
||
|
||
emit_insn (gen_check_stack (last_addr));
|
||
}
|
||
#endif
|
||
|
||
/* If we have to generate explicit probes, see if we have a constant
|
||
small number of them to generate. If so, that's the easy case. */
|
||
else if (GET_CODE (size) == CONST_INT
|
||
&& INTVAL (size) < 10 * STACK_CHECK_PROBE_INTERVAL)
|
||
{
|
||
HOST_WIDE_INT offset;
|
||
|
||
/* Start probing at FIRST + N * STACK_CHECK_PROBE_INTERVAL
|
||
for values of N from 1 until it exceeds LAST. If only one
|
||
probe is needed, this will not generate any code. Then probe
|
||
at LAST. */
|
||
for (offset = first + STACK_CHECK_PROBE_INTERVAL;
|
||
offset < INTVAL (size);
|
||
offset = offset + STACK_CHECK_PROBE_INTERVAL)
|
||
emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
|
||
stack_pointer_rtx,
|
||
GEN_INT (offset)));
|
||
|
||
emit_stack_probe (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
|
||
stack_pointer_rtx,
|
||
plus_constant (size, first)));
|
||
}
|
||
|
||
/* In the variable case, do the same as above, but in a loop. We emit loop
|
||
notes so that loop optimization can be done. */
|
||
else
|
||
{
|
||
rtx test_addr
|
||
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
|
||
stack_pointer_rtx,
|
||
GEN_INT (first + STACK_CHECK_PROBE_INTERVAL)),
|
||
NULL_RTX);
|
||
rtx last_addr
|
||
= force_operand (gen_rtx_fmt_ee (STACK_GROW_OP, Pmode,
|
||
stack_pointer_rtx,
|
||
plus_constant (size, first)),
|
||
NULL_RTX);
|
||
rtx incr = GEN_INT (STACK_CHECK_PROBE_INTERVAL);
|
||
rtx loop_lab = gen_label_rtx ();
|
||
rtx test_lab = gen_label_rtx ();
|
||
rtx end_lab = gen_label_rtx ();
|
||
rtx temp;
|
||
|
||
if (!REG_P (test_addr)
|
||
|| REGNO (test_addr) < FIRST_PSEUDO_REGISTER)
|
||
test_addr = force_reg (Pmode, test_addr);
|
||
|
||
emit_jump (test_lab);
|
||
|
||
emit_label (loop_lab);
|
||
emit_stack_probe (test_addr);
|
||
|
||
#ifdef STACK_GROWS_DOWNWARD
|
||
#define CMP_OPCODE GTU
|
||
temp = expand_binop (Pmode, sub_optab, test_addr, incr, test_addr,
|
||
1, OPTAB_WIDEN);
|
||
#else
|
||
#define CMP_OPCODE LTU
|
||
temp = expand_binop (Pmode, add_optab, test_addr, incr, test_addr,
|
||
1, OPTAB_WIDEN);
|
||
#endif
|
||
|
||
gcc_assert (temp == test_addr);
|
||
|
||
emit_label (test_lab);
|
||
emit_cmp_and_jump_insns (test_addr, last_addr, CMP_OPCODE,
|
||
NULL_RTX, Pmode, 1, loop_lab);
|
||
emit_jump (end_lab);
|
||
emit_label (end_lab);
|
||
|
||
emit_stack_probe (last_addr);
|
||
}
|
||
}
|
||
|
||
/* Return an rtx representing the register or memory location
|
||
in which a scalar value of data type VALTYPE
|
||
was returned by a function call to function FUNC.
|
||
FUNC is a FUNCTION_DECL, FNTYPE a FUNCTION_TYPE node if the precise
|
||
function is known, otherwise 0.
|
||
OUTGOING is 1 if on a machine with register windows this function
|
||
should return the register in which the function will put its result
|
||
and 0 otherwise. */
|
||
|
||
rtx
|
||
hard_function_value (tree valtype, tree func, tree fntype,
|
||
int outgoing ATTRIBUTE_UNUSED)
|
||
{
|
||
rtx val;
|
||
|
||
val = targetm.calls.function_value (valtype, func ? func : fntype, outgoing);
|
||
|
||
if (REG_P (val)
|
||
&& GET_MODE (val) == BLKmode)
|
||
{
|
||
unsigned HOST_WIDE_INT bytes = int_size_in_bytes (valtype);
|
||
enum machine_mode tmpmode;
|
||
|
||
/* int_size_in_bytes can return -1. We don't need a check here
|
||
since the value of bytes will then be large enough that no
|
||
mode will match anyway. */
|
||
|
||
for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT);
|
||
tmpmode != VOIDmode;
|
||
tmpmode = GET_MODE_WIDER_MODE (tmpmode))
|
||
{
|
||
/* Have we found a large enough mode? */
|
||
if (GET_MODE_SIZE (tmpmode) >= bytes)
|
||
break;
|
||
}
|
||
|
||
/* No suitable mode found. */
|
||
gcc_assert (tmpmode != VOIDmode);
|
||
|
||
PUT_MODE (val, tmpmode);
|
||
}
|
||
return val;
|
||
}
|
||
|
||
/* Return an rtx representing the register or memory location
|
||
in which a scalar value of mode MODE was returned by a library call. */
|
||
|
||
rtx
|
||
hard_libcall_value (enum machine_mode mode)
|
||
{
|
||
return LIBCALL_VALUE (mode);
|
||
}
|
||
|
||
/* Look up the tree code for a given rtx code
|
||
to provide the arithmetic operation for REAL_ARITHMETIC.
|
||
The function returns an int because the caller may not know
|
||
what `enum tree_code' means. */
|
||
|
||
int
|
||
rtx_to_tree_code (enum rtx_code code)
|
||
{
|
||
enum tree_code tcode;
|
||
|
||
switch (code)
|
||
{
|
||
case PLUS:
|
||
tcode = PLUS_EXPR;
|
||
break;
|
||
case MINUS:
|
||
tcode = MINUS_EXPR;
|
||
break;
|
||
case MULT:
|
||
tcode = MULT_EXPR;
|
||
break;
|
||
case DIV:
|
||
tcode = RDIV_EXPR;
|
||
break;
|
||
case SMIN:
|
||
tcode = MIN_EXPR;
|
||
break;
|
||
case SMAX:
|
||
tcode = MAX_EXPR;
|
||
break;
|
||
default:
|
||
tcode = LAST_AND_UNUSED_TREE_CODE;
|
||
break;
|
||
}
|
||
return ((int) tcode);
|
||
}
|
||
|
||
#include "gt-explow.h"
|