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/* RTL simplification functions for GNU compiler.
Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "rtl.h"
#include "tree.h"
#include "tm_p.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "flags.h"
#include "real.h"
#include "insn-config.h"
#include "recog.h"
#include "function.h"
#include "expr.h"
#include "toplev.h"
#include "output.h"
#include "ggc.h"
#include "target.h"
/* Simplification and canonicalization of RTL. */
/* Much code operates on (low, high) pairs; the low value is an
unsigned wide int, the high value a signed wide int. We
occasionally need to sign extend from low to high as if low were a
signed wide int. */
#define HWI_SIGN_EXTEND(low) \
((((HOST_WIDE_INT) low) < 0) ? ((HOST_WIDE_INT) -1) : ((HOST_WIDE_INT) 0))
static rtx neg_const_int (enum machine_mode, const_rtx);
static bool plus_minus_operand_p (const_rtx);
static bool simplify_plus_minus_op_data_cmp (rtx, rtx);
static rtx simplify_plus_minus (enum rtx_code, enum machine_mode, rtx, rtx);
static rtx simplify_immed_subreg (enum machine_mode, rtx, enum machine_mode,
unsigned int);
static rtx simplify_associative_operation (enum rtx_code, enum machine_mode,
rtx, rtx);
static rtx simplify_relational_operation_1 (enum rtx_code, enum machine_mode,
enum machine_mode, rtx, rtx);
static rtx simplify_unary_operation_1 (enum rtx_code, enum machine_mode, rtx);
static rtx simplify_binary_operation_1 (enum rtx_code, enum machine_mode,
rtx, rtx, rtx, rtx);
/* Negate a CONST_INT rtx, truncating (because a conversion from a
maximally negative number can overflow). */
static rtx
neg_const_int (enum machine_mode mode, const_rtx i)
{
return gen_int_mode (- INTVAL (i), mode);
}
/* Test whether expression, X, is an immediate constant that represents
the most significant bit of machine mode MODE. */
bool
mode_signbit_p (enum machine_mode mode, const_rtx x)
{
unsigned HOST_WIDE_INT val;
unsigned int width;
if (GET_MODE_CLASS (mode) != MODE_INT)
return false;
width = GET_MODE_BITSIZE (mode);
if (width == 0)
return false;
if (width <= HOST_BITS_PER_WIDE_INT
&& GET_CODE (x) == CONST_INT)
val = INTVAL (x);
else if (width <= 2 * HOST_BITS_PER_WIDE_INT
&& GET_CODE (x) == CONST_DOUBLE
&& CONST_DOUBLE_LOW (x) == 0)
{
val = CONST_DOUBLE_HIGH (x);
width -= HOST_BITS_PER_WIDE_INT;
}
else
return false;
if (width < HOST_BITS_PER_WIDE_INT)
val &= ((unsigned HOST_WIDE_INT) 1 << width) - 1;
return val == ((unsigned HOST_WIDE_INT) 1 << (width - 1));
}
/* Make a binary operation by properly ordering the operands and
seeing if the expression folds. */
rtx
simplify_gen_binary (enum rtx_code code, enum machine_mode mode, rtx op0,
rtx op1)
{
rtx tem;
/* If this simplifies, do it. */
tem = simplify_binary_operation (code, mode, op0, op1);
if (tem)
return tem;
/* Put complex operands first and constants second if commutative. */
if (GET_RTX_CLASS (code) == RTX_COMM_ARITH
&& swap_commutative_operands_p (op0, op1))
tem = op0, op0 = op1, op1 = tem;
return gen_rtx_fmt_ee (code, mode, op0, op1);
}
/* If X is a MEM referencing the constant pool, return the real value.
Otherwise return X. */
rtx
avoid_constant_pool_reference (rtx x)
{
rtx c, tmp, addr;
enum machine_mode cmode;
HOST_WIDE_INT offset = 0;
switch (GET_CODE (x))
{
case MEM:
break;
case FLOAT_EXTEND:
/* Handle float extensions of constant pool references. */
tmp = XEXP (x, 0);
c = avoid_constant_pool_reference (tmp);
if (c != tmp && GET_CODE (c) == CONST_DOUBLE)
{
REAL_VALUE_TYPE d;
REAL_VALUE_FROM_CONST_DOUBLE (d, c);
return CONST_DOUBLE_FROM_REAL_VALUE (d, GET_MODE (x));
}
return x;
default:
return x;
}
if (GET_MODE (x) == BLKmode)
return x;
addr = XEXP (x, 0);
/* Call target hook to avoid the effects of -fpic etc.... */
addr = targetm.delegitimize_address (addr);
/* Split the address into a base and integer offset. */
if (GET_CODE (addr) == CONST
&& GET_CODE (XEXP (addr, 0)) == PLUS
&& GET_CODE (XEXP (XEXP (addr, 0), 1)) == CONST_INT)
{
offset = INTVAL (XEXP (XEXP (addr, 0), 1));
addr = XEXP (XEXP (addr, 0), 0);
}
if (GET_CODE (addr) == LO_SUM)
addr = XEXP (addr, 1);
/* If this is a constant pool reference, we can turn it into its
constant and hope that simplifications happen. */
if (GET_CODE (addr) == SYMBOL_REF
&& CONSTANT_POOL_ADDRESS_P (addr))
{
c = get_pool_constant (addr);
cmode = get_pool_mode (addr);
/* If we're accessing the constant in a different mode than it was
originally stored, attempt to fix that up via subreg simplifications.
If that fails we have no choice but to return the original memory. */
if (offset != 0 || cmode != GET_MODE (x))
{
rtx tem = simplify_subreg (GET_MODE (x), c, cmode, offset);
if (tem && CONSTANT_P (tem))
return tem;
}
else
return c;
}
return x;
}
/* Make a unary operation by first seeing if it folds and otherwise making
the specified operation. */
rtx
simplify_gen_unary (enum rtx_code code, enum machine_mode mode, rtx op,
enum machine_mode op_mode)
{
rtx tem;
/* If this simplifies, use it. */
if ((tem = simplify_unary_operation (code, mode, op, op_mode)) != 0)
return tem;
return gen_rtx_fmt_e (code, mode, op);
}
/* Likewise for ternary operations. */
rtx
simplify_gen_ternary (enum rtx_code code, enum machine_mode mode,
enum machine_mode op0_mode, rtx op0, rtx op1, rtx op2)
{
rtx tem;
/* If this simplifies, use it. */
if (0 != (tem = simplify_ternary_operation (code, mode, op0_mode,
op0, op1, op2)))
return tem;
return gen_rtx_fmt_eee (code, mode, op0, op1, op2);
}
/* Likewise, for relational operations.
CMP_MODE specifies mode comparison is done in. */
rtx
simplify_gen_relational (enum rtx_code code, enum machine_mode mode,
enum machine_mode cmp_mode, rtx op0, rtx op1)
{
rtx tem;
if (0 != (tem = simplify_relational_operation (code, mode, cmp_mode,
op0, op1)))
return tem;
return gen_rtx_fmt_ee (code, mode, op0, op1);
}
/* Replace all occurrences of OLD_RTX in X with NEW_RTX and try to simplify the
resulting RTX. Return a new RTX which is as simplified as possible. */
rtx
simplify_replace_rtx (rtx x, const_rtx old_rtx, rtx new_rtx)
{
enum rtx_code code = GET_CODE (x);
enum machine_mode mode = GET_MODE (x);
enum machine_mode op_mode;
rtx op0, op1, op2;
/* If X is OLD_RTX, return NEW_RTX. Otherwise, if this is an expression, try
to build a new expression substituting recursively. If we can't do
anything, return our input. */
if (x == old_rtx)
return new_rtx;
switch (GET_RTX_CLASS (code))
{
case RTX_UNARY:
op0 = XEXP (x, 0);
op_mode = GET_MODE (op0);
op0 = simplify_replace_rtx (op0, old_rtx, new_rtx);
if (op0 == XEXP (x, 0))
return x;
return simplify_gen_unary (code, mode, op0, op_mode);
case RTX_BIN_ARITH:
case RTX_COMM_ARITH:
op0 = simplify_replace_rtx (XEXP (x, 0), old_rtx, new_rtx);
op1 = simplify_replace_rtx (XEXP (x, 1), old_rtx, new_rtx);
if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1))
return x;
return simplify_gen_binary (code, mode, op0, op1);
case RTX_COMPARE:
case RTX_COMM_COMPARE:
op0 = XEXP (x, 0);
op1 = XEXP (x, 1);
op_mode = GET_MODE (op0) != VOIDmode ? GET_MODE (op0) : GET_MODE (op1);
op0 = simplify_replace_rtx (op0, old_rtx, new_rtx);
op1 = simplify_replace_rtx (op1, old_rtx, new_rtx);
if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1))
return x;
return simplify_gen_relational (code, mode, op_mode, op0, op1);
case RTX_TERNARY:
case RTX_BITFIELD_OPS:
op0 = XEXP (x, 0);
op_mode = GET_MODE (op0);
op0 = simplify_replace_rtx (op0, old_rtx, new_rtx);
op1 = simplify_replace_rtx (XEXP (x, 1), old_rtx, new_rtx);
op2 = simplify_replace_rtx (XEXP (x, 2), old_rtx, new_rtx);
if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1) && op2 == XEXP (x, 2))
return x;
if (op_mode == VOIDmode)
op_mode = GET_MODE (op0);
return simplify_gen_ternary (code, mode, op_mode, op0, op1, op2);
case RTX_EXTRA:
/* The only case we try to handle is a SUBREG. */
if (code == SUBREG)
{
op0 = simplify_replace_rtx (SUBREG_REG (x), old_rtx, new_rtx);
if (op0 == SUBREG_REG (x))
return x;
op0 = simplify_gen_subreg (GET_MODE (x), op0,
GET_MODE (SUBREG_REG (x)),
SUBREG_BYTE (x));
return op0 ? op0 : x;
}
break;
case RTX_OBJ:
if (code == MEM)
{
op0 = simplify_replace_rtx (XEXP (x, 0), old_rtx, new_rtx);
if (op0 == XEXP (x, 0))
return x;
return replace_equiv_address_nv (x, op0);
}
else if (code == LO_SUM)
{
op0 = simplify_replace_rtx (XEXP (x, 0), old_rtx, new_rtx);
op1 = simplify_replace_rtx (XEXP (x, 1), old_rtx, new_rtx);
/* (lo_sum (high x) x) -> x */
if (GET_CODE (op0) == HIGH && rtx_equal_p (XEXP (op0, 0), op1))
return op1;
if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1))
return x;
return gen_rtx_LO_SUM (mode, op0, op1);
}
else if (code == REG)
{
if (rtx_equal_p (x, old_rtx))
return new_rtx;
}
break;
default:
break;
}
return x;
}
/* Try to simplify a unary operation CODE whose output mode is to be
MODE with input operand OP whose mode was originally OP_MODE.
Return zero if no simplification can be made. */
rtx
simplify_unary_operation (enum rtx_code code, enum machine_mode mode,
rtx op, enum machine_mode op_mode)
{
rtx trueop, tem;
if (GET_CODE (op) == CONST)
op = XEXP (op, 0);
trueop = avoid_constant_pool_reference (op);
tem = simplify_const_unary_operation (code, mode, trueop, op_mode);
if (tem)
return tem;
return simplify_unary_operation_1 (code, mode, op);
}
/* Perform some simplifications we can do even if the operands
aren't constant. */
static rtx
simplify_unary_operation_1 (enum rtx_code code, enum machine_mode mode, rtx op)
{
enum rtx_code reversed;
rtx temp;
switch (code)
{
case NOT:
/* (not (not X)) == X. */
if (GET_CODE (op) == NOT)
return XEXP (op, 0);
/* (not (eq X Y)) == (ne X Y), etc. if BImode or the result of the
comparison is all ones. */
if (COMPARISON_P (op)
&& (mode == BImode || STORE_FLAG_VALUE == -1)
&& ((reversed = reversed_comparison_code (op, NULL_RTX)) != UNKNOWN))
return simplify_gen_relational (reversed, mode, VOIDmode,
XEXP (op, 0), XEXP (op, 1));
/* (not (plus X -1)) can become (neg X). */
if (GET_CODE (op) == PLUS
&& XEXP (op, 1) == constm1_rtx)
return simplify_gen_unary (NEG, mode, XEXP (op, 0), mode);
/* Similarly, (not (neg X)) is (plus X -1). */
if (GET_CODE (op) == NEG)
return plus_constant (XEXP (op, 0), -1);
/* (not (xor X C)) for C constant is (xor X D) with D = ~C. */
if (GET_CODE (op) == XOR
&& GET_CODE (XEXP (op, 1)) == CONST_INT
&& (temp = simplify_unary_operation (NOT, mode,
XEXP (op, 1), mode)) != 0)
return simplify_gen_binary (XOR, mode, XEXP (op, 0), temp);
/* (not (plus X C)) for signbit C is (xor X D) with D = ~C. */
if (GET_CODE (op) == PLUS
&& GET_CODE (XEXP (op, 1)) == CONST_INT
&& mode_signbit_p (mode, XEXP (op, 1))
&& (temp = simplify_unary_operation (NOT, mode,
XEXP (op, 1), mode)) != 0)
return simplify_gen_binary (XOR, mode, XEXP (op, 0), temp);
/* (not (ashift 1 X)) is (rotate ~1 X). We used to do this for
operands other than 1, but that is not valid. We could do a
similar simplification for (not (lshiftrt C X)) where C is
just the sign bit, but this doesn't seem common enough to
bother with. */
if (GET_CODE (op) == ASHIFT
&& XEXP (op, 0) == const1_rtx)
{
temp = simplify_gen_unary (NOT, mode, const1_rtx, mode);
return simplify_gen_binary (ROTATE, mode, temp, XEXP (op, 1));
}
/* (not (ashiftrt foo C)) where C is the number of bits in FOO
minus 1 is (ge foo (const_int 0)) if STORE_FLAG_VALUE is -1,
so we can perform the above simplification. */
if (STORE_FLAG_VALUE == -1
&& GET_CODE (op) == ASHIFTRT
&& GET_CODE (XEXP (op, 1)) == CONST_INT
&& INTVAL (XEXP (op, 1)) == GET_MODE_BITSIZE (mode) - 1)
return simplify_gen_relational (GE, mode, VOIDmode,
XEXP (op, 0), const0_rtx);
if (GET_CODE (op) == SUBREG
&& subreg_lowpart_p (op)
&& (GET_MODE_SIZE (GET_MODE (op))
< GET_MODE_SIZE (GET_MODE (SUBREG_REG (op))))
&& GET_CODE (SUBREG_REG (op)) == ASHIFT
&& XEXP (SUBREG_REG (op), 0) == const1_rtx)
{
enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op));
rtx x;
x = gen_rtx_ROTATE (inner_mode,
simplify_gen_unary (NOT, inner_mode, const1_rtx,
inner_mode),
XEXP (SUBREG_REG (op), 1));
return rtl_hooks.gen_lowpart_no_emit (mode, x);
}
/* Apply De Morgan's laws to reduce number of patterns for machines
with negating logical insns (and-not, nand, etc.). If result has
only one NOT, put it first, since that is how the patterns are
coded. */
if (GET_CODE (op) == IOR || GET_CODE (op) == AND)
{
rtx in1 = XEXP (op, 0), in2 = XEXP (op, 1);
enum machine_mode op_mode;
op_mode = GET_MODE (in1);
in1 = simplify_gen_unary (NOT, op_mode, in1, op_mode);
op_mode = GET_MODE (in2);
if (op_mode == VOIDmode)
op_mode = mode;
in2 = simplify_gen_unary (NOT, op_mode, in2, op_mode);
if (GET_CODE (in2) == NOT && GET_CODE (in1) != NOT)
{
rtx tem = in2;
in2 = in1; in1 = tem;
}
return gen_rtx_fmt_ee (GET_CODE (op) == IOR ? AND : IOR,
mode, in1, in2);
}
break;
case NEG:
/* (neg (neg X)) == X. */
if (GET_CODE (op) == NEG)
return XEXP (op, 0);
/* (neg (plus X 1)) can become (not X). */
if (GET_CODE (op) == PLUS
&& XEXP (op, 1) == const1_rtx)
return simplify_gen_unary (NOT, mode, XEXP (op, 0), mode);
/* Similarly, (neg (not X)) is (plus X 1). */
if (GET_CODE (op) == NOT)
return plus_constant (XEXP (op, 0), 1);
/* (neg (minus X Y)) can become (minus Y X). This transformation
isn't safe for modes with signed zeros, since if X and Y are
both +0, (minus Y X) is the same as (minus X Y). If the
rounding mode is towards +infinity (or -infinity) then the two
expressions will be rounded differently. */
if (GET_CODE (op) == MINUS
&& !HONOR_SIGNED_ZEROS (mode)
&& !HONOR_SIGN_DEPENDENT_ROUNDING (mode))
return simplify_gen_binary (MINUS, mode, XEXP (op, 1), XEXP (op, 0));
if (GET_CODE (op) == PLUS
&& !HONOR_SIGNED_ZEROS (mode)
&& !HONOR_SIGN_DEPENDENT_ROUNDING (mode))
{
/* (neg (plus A C)) is simplified to (minus -C A). */
if (GET_CODE (XEXP (op, 1)) == CONST_INT
|| GET_CODE (XEXP (op, 1)) == CONST_DOUBLE)
{
temp = simplify_unary_operation (NEG, mode, XEXP (op, 1), mode);
if (temp)
return simplify_gen_binary (MINUS, mode, temp, XEXP (op, 0));
}
/* (neg (plus A B)) is canonicalized to (minus (neg A) B). */
temp = simplify_gen_unary (NEG, mode, XEXP (op, 0), mode);
return simplify_gen_binary (MINUS, mode, temp, XEXP (op, 1));
}
/* (neg (mult A B)) becomes (mult (neg A) B).
This works even for floating-point values. */
if (GET_CODE (op) == MULT
&& !HONOR_SIGN_DEPENDENT_ROUNDING (mode))
{
temp = simplify_gen_unary (NEG, mode, XEXP (op, 0), mode);
return simplify_gen_binary (MULT, mode, temp, XEXP (op, 1));
}
/* NEG commutes with ASHIFT since it is multiplication. Only do
this if we can then eliminate the NEG (e.g., if the operand
is a constant). */
if (GET_CODE (op) == ASHIFT)
{
temp = simplify_unary_operation (NEG, mode, XEXP (op, 0), mode);
if (temp)
return simplify_gen_binary (ASHIFT, mode, temp, XEXP (op, 1));
}
/* (neg (ashiftrt X C)) can be replaced by (lshiftrt X C) when
C is equal to the width of MODE minus 1. */
if (GET_CODE (op) == ASHIFTRT
&& GET_CODE (XEXP (op, 1)) == CONST_INT
&& INTVAL (XEXP (op, 1)) == GET_MODE_BITSIZE (mode) - 1)
return simplify_gen_binary (LSHIFTRT, mode,
XEXP (op, 0), XEXP (op, 1));
/* (neg (lshiftrt X C)) can be replaced by (ashiftrt X C) when
C is equal to the width of MODE minus 1. */
if (GET_CODE (op) == LSHIFTRT
&& GET_CODE (XEXP (op, 1)) == CONST_INT
&& INTVAL (XEXP (op, 1)) == GET_MODE_BITSIZE (mode) - 1)
return simplify_gen_binary (ASHIFTRT, mode,
XEXP (op, 0), XEXP (op, 1));
/* (neg (xor A 1)) is (plus A -1) if A is known to be either 0 or 1. */
if (GET_CODE (op) == XOR
&& XEXP (op, 1) == const1_rtx
&& nonzero_bits (XEXP (op, 0), mode) == 1)
return plus_constant (XEXP (op, 0), -1);
/* (neg (lt x 0)) is (ashiftrt X C) if STORE_FLAG_VALUE is 1. */
/* (neg (lt x 0)) is (lshiftrt X C) if STORE_FLAG_VALUE is -1. */
if (GET_CODE (op) == LT
&& XEXP (op, 1) == const0_rtx
&& SCALAR_INT_MODE_P (GET_MODE (XEXP (op, 0))))
{
enum machine_mode inner = GET_MODE (XEXP (op, 0));
int isize = GET_MODE_BITSIZE (inner);
if (STORE_FLAG_VALUE == 1)
{
temp = simplify_gen_binary (ASHIFTRT, inner, XEXP (op, 0),
GEN_INT (isize - 1));
if (mode == inner)
return temp;
if (GET_MODE_BITSIZE (mode) > isize)
return simplify_gen_unary (SIGN_EXTEND, mode, temp, inner);
return simplify_gen_unary (TRUNCATE, mode, temp, inner);
}
else if (STORE_FLAG_VALUE == -1)
{
temp = simplify_gen_binary (LSHIFTRT, inner, XEXP (op, 0),
GEN_INT (isize - 1));
if (mode == inner)
return temp;
if (GET_MODE_BITSIZE (mode) > isize)
return simplify_gen_unary (ZERO_EXTEND, mode, temp, inner);
return simplify_gen_unary (TRUNCATE, mode, temp, inner);
}
}
break;
case TRUNCATE:
/* We can't handle truncation to a partial integer mode here
because we don't know the real bitsize of the partial
integer mode. */
if (GET_MODE_CLASS (mode) == MODE_PARTIAL_INT)
break;
/* (truncate:SI ({sign,zero}_extend:DI foo:SI)) == foo:SI. */
if ((GET_CODE (op) == SIGN_EXTEND
|| GET_CODE (op) == ZERO_EXTEND)
&& GET_MODE (XEXP (op, 0)) == mode)
return XEXP (op, 0);
/* (truncate:SI (OP:DI ({sign,zero}_extend:DI foo:SI))) is
(OP:SI foo:SI) if OP is NEG or ABS. */
if ((GET_CODE (op) == ABS
|| GET_CODE (op) == NEG)
&& (GET_CODE (XEXP (op, 0)) == SIGN_EXTEND
|| GET_CODE (XEXP (op, 0)) == ZERO_EXTEND)
&& GET_MODE (XEXP (XEXP (op, 0), 0)) == mode)
return simplify_gen_unary (GET_CODE (op), mode,
XEXP (XEXP (op, 0), 0), mode);
/* (truncate:A (subreg:B (truncate:C X) 0)) is
(truncate:A X). */
if (GET_CODE (op) == SUBREG
&& GET_CODE (SUBREG_REG (op)) == TRUNCATE
&& subreg_lowpart_p (op))
return simplify_gen_unary (TRUNCATE, mode, XEXP (SUBREG_REG (op), 0),
GET_MODE (XEXP (SUBREG_REG (op), 0)));
/* If we know that the value is already truncated, we can
replace the TRUNCATE with a SUBREG. Note that this is also
valid if TRULY_NOOP_TRUNCATION is false for the corresponding
modes we just have to apply a different definition for
truncation. But don't do this for an (LSHIFTRT (MULT ...))
since this will cause problems with the umulXi3_highpart
patterns. */
if ((TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode),
GET_MODE_BITSIZE (GET_MODE (op)))
? (num_sign_bit_copies (op, GET_MODE (op))
> (unsigned int) (GET_MODE_BITSIZE (GET_MODE (op))
- GET_MODE_BITSIZE (mode)))
: truncated_to_mode (mode, op))
&& ! (GET_CODE (op) == LSHIFTRT
&& GET_CODE (XEXP (op, 0)) == MULT))
return rtl_hooks.gen_lowpart_no_emit (mode, op);
/* A truncate of a comparison can be replaced with a subreg if
STORE_FLAG_VALUE permits. This is like the previous test,
but it works even if the comparison is done in a mode larger
than HOST_BITS_PER_WIDE_INT. */
if (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
&& COMPARISON_P (op)
&& ((HOST_WIDE_INT) STORE_FLAG_VALUE & ~GET_MODE_MASK (mode)) == 0)
return rtl_hooks.gen_lowpart_no_emit (mode, op);
break;
case FLOAT_TRUNCATE:
if (DECIMAL_FLOAT_MODE_P (mode))
break;
/* (float_truncate:SF (float_extend:DF foo:SF)) = foo:SF. */
if (GET_CODE (op) == FLOAT_EXTEND
&& GET_MODE (XEXP (op, 0)) == mode)
return XEXP (op, 0);
/* (float_truncate:SF (float_truncate:DF foo:XF))
= (float_truncate:SF foo:XF).
This may eliminate double rounding, so it is unsafe.
(float_truncate:SF (float_extend:XF foo:DF))
= (float_truncate:SF foo:DF).
(float_truncate:DF (float_extend:XF foo:SF))
= (float_extend:SF foo:DF). */
if ((GET_CODE (op) == FLOAT_TRUNCATE
&& flag_unsafe_math_optimizations)
|| GET_CODE (op) == FLOAT_EXTEND)
return simplify_gen_unary (GET_MODE_SIZE (GET_MODE (XEXP (op,
0)))
> GET_MODE_SIZE (mode)
? FLOAT_TRUNCATE : FLOAT_EXTEND,
mode,
XEXP (op, 0), mode);
/* (float_truncate (float x)) is (float x) */
if (GET_CODE (op) == FLOAT
&& (flag_unsafe_math_optimizations
|| (SCALAR_FLOAT_MODE_P (GET_MODE (op))
&& ((unsigned)significand_size (GET_MODE (op))
>= (GET_MODE_BITSIZE (GET_MODE (XEXP (op, 0)))
- num_sign_bit_copies (XEXP (op, 0),
GET_MODE (XEXP (op, 0))))))))
return simplify_gen_unary (FLOAT, mode,
XEXP (op, 0),
GET_MODE (XEXP (op, 0)));
/* (float_truncate:SF (OP:DF (float_extend:DF foo:sf))) is
(OP:SF foo:SF) if OP is NEG or ABS. */
if ((GET_CODE (op) == ABS
|| GET_CODE (op) == NEG)
&& GET_CODE (XEXP (op, 0)) == FLOAT_EXTEND
&& GET_MODE (XEXP (XEXP (op, 0), 0)) == mode)
return simplify_gen_unary (GET_CODE (op), mode,
XEXP (XEXP (op, 0), 0), mode);
/* (float_truncate:SF (subreg:DF (float_truncate:SF X) 0))
is (float_truncate:SF x). */
if (GET_CODE (op) == SUBREG
&& subreg_lowpart_p (op)
&& GET_CODE (SUBREG_REG (op)) == FLOAT_TRUNCATE)
return SUBREG_REG (op);
break;
case FLOAT_EXTEND:
if (DECIMAL_FLOAT_MODE_P (mode))
break;
/* (float_extend (float_extend x)) is (float_extend x)
(float_extend (float x)) is (float x) assuming that double
rounding can't happen.
*/
if (GET_CODE (op) == FLOAT_EXTEND
|| (GET_CODE (op) == FLOAT
&& SCALAR_FLOAT_MODE_P (GET_MODE (op))
&& ((unsigned)significand_size (GET_MODE (op))
>= (GET_MODE_BITSIZE (GET_MODE (XEXP (op, 0)))
- num_sign_bit_copies (XEXP (op, 0),
GET_MODE (XEXP (op, 0)))))))
return simplify_gen_unary (GET_CODE (op), mode,
XEXP (op, 0),
GET_MODE (XEXP (op, 0)));
break;
case ABS:
/* (abs (neg <foo>)) -> (abs <foo>) */
if (GET_CODE (op) == NEG)
return simplify_gen_unary (ABS, mode, XEXP (op, 0),
GET_MODE (XEXP (op, 0)));
/* If the mode of the operand is VOIDmode (i.e. if it is ASM_OPERANDS),
do nothing. */
if (GET_MODE (op) == VOIDmode)
break;
/* If operand is something known to be positive, ignore the ABS. */
if (GET_CODE (op) == FFS || GET_CODE (op) == ABS
|| ((GET_MODE_BITSIZE (GET_MODE (op))
<= HOST_BITS_PER_WIDE_INT)
&& ((nonzero_bits (op, GET_MODE (op))
& ((HOST_WIDE_INT) 1
<< (GET_MODE_BITSIZE (GET_MODE (op)) - 1)))
== 0)))
return op;
/* If operand is known to be only -1 or 0, convert ABS to NEG. */
if (num_sign_bit_copies (op, mode) == GET_MODE_BITSIZE (mode))
return gen_rtx_NEG (mode, op);
break;
case FFS:
/* (ffs (*_extend <X>)) = (ffs <X>) */
if (GET_CODE (op) == SIGN_EXTEND
|| GET_CODE (op) == ZERO_EXTEND)
return simplify_gen_unary (FFS, mode, XEXP (op, 0),
GET_MODE (XEXP (op, 0)));
break;
case POPCOUNT:
switch (GET_CODE (op))
{
case BSWAP:
case ZERO_EXTEND:
/* (popcount (zero_extend <X>)) = (popcount <X>) */
return simplify_gen_unary (POPCOUNT, mode, XEXP (op, 0),
GET_MODE (XEXP (op, 0)));
case ROTATE:
case ROTATERT:
/* Rotations don't affect popcount. */
if (!side_effects_p (XEXP (op, 1)))
return simplify_gen_unary (POPCOUNT, mode, XEXP (op, 0),
GET_MODE (XEXP (op, 0)));
break;
default:
break;
}
break;
case PARITY:
switch (GET_CODE (op))
{
case NOT:
case BSWAP:
case ZERO_EXTEND:
case SIGN_EXTEND:
return simplify_gen_unary (PARITY, mode, XEXP (op, 0),
GET_MODE (XEXP (op, 0)));
case ROTATE:
case ROTATERT:
/* Rotations don't affect parity. */
if (!side_effects_p (XEXP (op, 1)))
return simplify_gen_unary (PARITY, mode, XEXP (op, 0),
GET_MODE (XEXP (op, 0)));
break;
default:
break;
}
break;
case BSWAP:
/* (bswap (bswap x)) -> x. */
if (GET_CODE (op) == BSWAP)
return XEXP (op, 0);
break;
case FLOAT:
/* (float (sign_extend <X>)) = (float <X>). */
if (GET_CODE (op) == SIGN_EXTEND)
return simplify_gen_unary (FLOAT, mode, XEXP (op, 0),
GET_MODE (XEXP (op, 0)));
break;
case SIGN_EXTEND:
/* (sign_extend (truncate (minus (label_ref L1) (label_ref L2))))
becomes just the MINUS if its mode is MODE. This allows
folding switch statements on machines using casesi (such as
the VAX). */
if (GET_CODE (op) == TRUNCATE
&& GET_MODE (XEXP (op, 0)) == mode
&& GET_CODE (XEXP (op, 0)) == MINUS
&& GET_CODE (XEXP (XEXP (op, 0), 0)) == LABEL_REF
&& GET_CODE (XEXP (XEXP (op, 0), 1)) == LABEL_REF)
return XEXP (op, 0);
/* Check for a sign extension of a subreg of a promoted
variable, where the promotion is sign-extended, and the
target mode is the same as the variable's promotion. */
if (GET_CODE (op) == SUBREG
&& SUBREG_PROMOTED_VAR_P (op)
&& ! SUBREG_PROMOTED_UNSIGNED_P (op)
&& GET_MODE_SIZE (mode) <= GET_MODE_SIZE (GET_MODE (XEXP (op, 0))))
return rtl_hooks.gen_lowpart_no_emit (mode, op);
#if defined(POINTERS_EXTEND_UNSIGNED) && !defined(HAVE_ptr_extend)
if (! POINTERS_EXTEND_UNSIGNED
&& mode == Pmode && GET_MODE (op) == ptr_mode
&& (CONSTANT_P (op)
|| (GET_CODE (op) == SUBREG
&& REG_P (SUBREG_REG (op))
&& REG_POINTER (SUBREG_REG (op))
&& GET_MODE (SUBREG_REG (op)) == Pmode)))
return convert_memory_address (Pmode, op);
#endif
break;
case ZERO_EXTEND:
/* Check for a zero extension of a subreg of a promoted
variable, where the promotion is zero-extended, and the
target mode is the same as the variable's promotion. */
if (GET_CODE (op) == SUBREG
&& SUBREG_PROMOTED_VAR_P (op)
&& SUBREG_PROMOTED_UNSIGNED_P (op) > 0
&& GET_MODE_SIZE (mode) <= GET_MODE_SIZE (GET_MODE (XEXP (op, 0))))
return rtl_hooks.gen_lowpart_no_emit (mode, op);
#if defined(POINTERS_EXTEND_UNSIGNED) && !defined(HAVE_ptr_extend)
if (POINTERS_EXTEND_UNSIGNED > 0
&& mode == Pmode && GET_MODE (op) == ptr_mode
&& (CONSTANT_P (op)
|| (GET_CODE (op) == SUBREG
&& REG_P (SUBREG_REG (op))
&& REG_POINTER (SUBREG_REG (op))
&& GET_MODE (SUBREG_REG (op)) == Pmode)))
return convert_memory_address (Pmode, op);
#endif
break;
default:
break;
}
return 0;
}
/* Try to compute the value of a unary operation CODE whose output mode is to
be MODE with input operand OP whose mode was originally OP_MODE.
Return zero if the value cannot be computed. */
rtx
simplify_const_unary_operation (enum rtx_code code, enum machine_mode mode,
rtx op, enum machine_mode op_mode)
{
unsigned int width = GET_MODE_BITSIZE (mode);
if (code == VEC_DUPLICATE)
{
gcc_assert (VECTOR_MODE_P (mode));
if (GET_MODE (op) != VOIDmode)
{
if (!VECTOR_MODE_P (GET_MODE (op)))
gcc_assert (GET_MODE_INNER (mode) == GET_MODE (op));
else
gcc_assert (GET_MODE_INNER (mode) == GET_MODE_INNER
(GET_MODE (op)));
}
if (GET_CODE (op) == CONST_INT || GET_CODE (op) == CONST_DOUBLE
|| GET_CODE (op) == CONST_VECTOR)
{
int elt_size = GET_MODE_SIZE (GET_MODE_INNER (mode));
unsigned n_elts = (GET_MODE_SIZE (mode) / elt_size);
rtvec v = rtvec_alloc (n_elts);
unsigned int i;
if (GET_CODE (op) != CONST_VECTOR)
for (i = 0; i < n_elts; i++)
RTVEC_ELT (v, i) = op;
else
{
enum machine_mode inmode = GET_MODE (op);
int in_elt_size = GET_MODE_SIZE (GET_MODE_INNER (inmode));
unsigned in_n_elts = (GET_MODE_SIZE (inmode) / in_elt_size);
gcc_assert (in_n_elts < n_elts);
gcc_assert ((n_elts % in_n_elts) == 0);
for (i = 0; i < n_elts; i++)
RTVEC_ELT (v, i) = CONST_VECTOR_ELT (op, i % in_n_elts);
}
return gen_rtx_CONST_VECTOR (mode, v);
}
}
if (VECTOR_MODE_P (mode) && GET_CODE (op) == CONST_VECTOR)
{
int elt_size = GET_MODE_SIZE (GET_MODE_INNER (mode));
unsigned n_elts = (GET_MODE_SIZE (mode) / elt_size);
enum machine_mode opmode = GET_MODE (op);
int op_elt_size = GET_MODE_SIZE (GET_MODE_INNER (opmode));
unsigned op_n_elts = (GET_MODE_SIZE (opmode) / op_elt_size);
rtvec v = rtvec_alloc (n_elts);
unsigned int i;
gcc_assert (op_n_elts == n_elts);
for (i = 0; i < n_elts; i++)
{
rtx x = simplify_unary_operation (code, GET_MODE_INNER (mode),
CONST_VECTOR_ELT (op, i),
GET_MODE_INNER (opmode));
if (!x)
return 0;
RTVEC_ELT (v, i) = x;
}
return gen_rtx_CONST_VECTOR (mode, v);
}
/* The order of these tests is critical so that, for example, we don't
check the wrong mode (input vs. output) for a conversion operation,
such as FIX. At some point, this should be simplified. */
if (code == FLOAT && GET_MODE (op) == VOIDmode
&& (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT))
{
HOST_WIDE_INT hv, lv;
REAL_VALUE_TYPE d;
if (GET_CODE (op) == CONST_INT)
lv = INTVAL (op), hv = HWI_SIGN_EXTEND (lv);
else
lv = CONST_DOUBLE_LOW (op), hv = CONST_DOUBLE_HIGH (op);
REAL_VALUE_FROM_INT (d, lv, hv, mode);
d = real_value_truncate (mode, d);
return CONST_DOUBLE_FROM_REAL_VALUE (d, mode);
}
else if (code == UNSIGNED_FLOAT && GET_MODE (op) == VOIDmode
&& (GET_CODE (op) == CONST_DOUBLE
|| GET_CODE (op) == CONST_INT))
{
HOST_WIDE_INT hv, lv;
REAL_VALUE_TYPE d;
if (GET_CODE (op) == CONST_INT)
lv = INTVAL (op), hv = HWI_SIGN_EXTEND (lv);
else
lv = CONST_DOUBLE_LOW (op), hv = CONST_DOUBLE_HIGH (op);
if (op_mode == VOIDmode)
{
/* We don't know how to interpret negative-looking numbers in
this case, so don't try to fold those. */
if (hv < 0)
return 0;
}
else if (GET_MODE_BITSIZE (op_mode) >= HOST_BITS_PER_WIDE_INT * 2)
;
else
hv = 0, lv &= GET_MODE_MASK (op_mode);
REAL_VALUE_FROM_UNSIGNED_INT (d, lv, hv, mode);
d = real_value_truncate (mode, d);
return CONST_DOUBLE_FROM_REAL_VALUE (d, mode);
}
if (GET_CODE (op) == CONST_INT
&& width <= HOST_BITS_PER_WIDE_INT && width > 0)
{
HOST_WIDE_INT arg0 = INTVAL (op);
HOST_WIDE_INT val;
switch (code)
{
case NOT:
val = ~ arg0;
break;
case NEG:
val = - arg0;
break;
case ABS:
val = (arg0 >= 0 ? arg0 : - arg0);
break;
case FFS:
/* Don't use ffs here. Instead, get low order bit and then its
number. If arg0 is zero, this will return 0, as desired. */
arg0 &= GET_MODE_MASK (mode);
val = exact_log2 (arg0 & (- arg0)) + 1;
break;
case CLZ:
arg0 &= GET_MODE_MASK (mode);
if (arg0 == 0 && CLZ_DEFINED_VALUE_AT_ZERO (mode, val))
;
else
val = GET_MODE_BITSIZE (mode) - floor_log2 (arg0) - 1;
break;
case CTZ:
arg0 &= GET_MODE_MASK (mode);
if (arg0 == 0)
{
/* Even if the value at zero is undefined, we have to come
up with some replacement. Seems good enough. */
if (! CTZ_DEFINED_VALUE_AT_ZERO (mode, val))
val = GET_MODE_BITSIZE (mode);
}
else
val = exact_log2 (arg0 & -arg0);
break;
case POPCOUNT:
arg0 &= GET_MODE_MASK (mode);
val = 0;
while (arg0)
val++, arg0 &= arg0 - 1;
break;
case PARITY:
arg0 &= GET_MODE_MASK (mode);
val = 0;
while (arg0)
val++, arg0 &= arg0 - 1;
val &= 1;
break;
case BSWAP:
{
unsigned int s;
val = 0;
for (s = 0; s < width; s += 8)
{
unsigned int d = width - s - 8;
unsigned HOST_WIDE_INT byte;
byte = (arg0 >> s) & 0xff;
val |= byte << d;
}
}
break;
case TRUNCATE:
val = arg0;
break;
case ZERO_EXTEND:
/* When zero-extending a CONST_INT, we need to know its
original mode. */
gcc_assert (op_mode != VOIDmode);
if (GET_MODE_BITSIZE (op_mode) == HOST_BITS_PER_WIDE_INT)
{
/* If we were really extending the mode,
we would have to distinguish between zero-extension
and sign-extension. */
gcc_assert (width == GET_MODE_BITSIZE (op_mode));
val = arg0;
}
else if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT)
val = arg0 & ~((HOST_WIDE_INT) (-1) << GET_MODE_BITSIZE (op_mode));
else
return 0;
break;
case SIGN_EXTEND:
if (op_mode == VOIDmode)
op_mode = mode;
if (GET_MODE_BITSIZE (op_mode) == HOST_BITS_PER_WIDE_INT)
{
/* If we were really extending the mode,
we would have to distinguish between zero-extension
and sign-extension. */
gcc_assert (width == GET_MODE_BITSIZE (op_mode));
val = arg0;
}
else if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT)
{
val
= arg0 & ~((HOST_WIDE_INT) (-1) << GET_MODE_BITSIZE (op_mode));
if (val
& ((HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (op_mode) - 1)))
val -= (HOST_WIDE_INT) 1 << GET_MODE_BITSIZE (op_mode);
}
else
return 0;
break;
case SQRT:
case FLOAT_EXTEND:
case FLOAT_TRUNCATE:
case SS_TRUNCATE:
case US_TRUNCATE:
case SS_NEG:
case US_NEG:
return 0;
default:
gcc_unreachable ();
}
return gen_int_mode (val, mode);
}
/* We can do some operations on integer CONST_DOUBLEs. Also allow
for a DImode operation on a CONST_INT. */
else if (GET_MODE (op) == VOIDmode
&& width <= HOST_BITS_PER_WIDE_INT * 2
&& (GET_CODE (op) == CONST_DOUBLE
|| GET_CODE (op) == CONST_INT))
{
unsigned HOST_WIDE_INT l1, lv;
HOST_WIDE_INT h1, hv;
if (GET_CODE (op) == CONST_DOUBLE)
l1 = CONST_DOUBLE_LOW (op), h1 = CONST_DOUBLE_HIGH (op);
else
l1 = INTVAL (op), h1 = HWI_SIGN_EXTEND (l1);
switch (code)
{
case NOT:
lv = ~ l1;
hv = ~ h1;
break;
case NEG:
neg_double (l1, h1, &lv, &hv);
break;
case ABS:
if (h1 < 0)
neg_double (l1, h1, &lv, &hv);
else
lv = l1, hv = h1;
break;
case FFS:
hv = 0;
if (l1 == 0)
{
if (h1 == 0)
lv = 0;
else
lv = HOST_BITS_PER_WIDE_INT + exact_log2 (h1 & -h1) + 1;
}
else
lv = exact_log2 (l1 & -l1) + 1;
break;
case CLZ:
hv = 0;
if (h1 != 0)
lv = GET_MODE_BITSIZE (mode) - floor_log2 (h1) - 1
- HOST_BITS_PER_WIDE_INT;
else if (l1 != 0)
lv = GET_MODE_BITSIZE (mode) - floor_log2 (l1) - 1;
else if (! CLZ_DEFINED_VALUE_AT_ZERO (mode, lv))
lv = GET_MODE_BITSIZE (mode);
break;
case CTZ:
hv = 0;
if (l1 != 0)
lv = exact_log2 (l1 & -l1);
else if (h1 != 0)
lv = HOST_BITS_PER_WIDE_INT + exact_log2 (h1 & -h1);
else if (! CTZ_DEFINED_VALUE_AT_ZERO (mode, lv))
lv = GET_MODE_BITSIZE (mode);
break;
case POPCOUNT:
hv = 0;
lv = 0;
while (l1)
lv++, l1 &= l1 - 1;
while (h1)
lv++, h1 &= h1 - 1;
break;
case PARITY:
hv = 0;
lv = 0;
while (l1)
lv++, l1 &= l1 - 1;
while (h1)
lv++, h1 &= h1 - 1;
lv &= 1;
break;
case BSWAP:
{
unsigned int s;
hv = 0;
lv = 0;
for (s = 0; s < width; s += 8)
{
unsigned int d = width - s - 8;
unsigned HOST_WIDE_INT byte;
if (s < HOST_BITS_PER_WIDE_INT)
byte = (l1 >> s) & 0xff;
else
byte = (h1 >> (s - HOST_BITS_PER_WIDE_INT)) & 0xff;
if (d < HOST_BITS_PER_WIDE_INT)
lv |= byte << d;
else
hv |= byte << (d - HOST_BITS_PER_WIDE_INT);
}
}
break;
case TRUNCATE:
/* This is just a change-of-mode, so do nothing. */
lv = l1, hv = h1;
break;
case ZERO_EXTEND:
gcc_assert (op_mode != VOIDmode);
if (GET_MODE_BITSIZE (op_mode) > HOST_BITS_PER_WIDE_INT)
return 0;
hv = 0;
lv = l1 & GET_MODE_MASK (op_mode);
break;
case SIGN_EXTEND:
if (op_mode == VOIDmode
|| GET_MODE_BITSIZE (op_mode) > HOST_BITS_PER_WIDE_INT)
return 0;
else
{
lv = l1 & GET_MODE_MASK (op_mode);
if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT
&& (lv & ((HOST_WIDE_INT) 1
<< (GET_MODE_BITSIZE (op_mode) - 1))) != 0)
lv -= (HOST_WIDE_INT) 1 << GET_MODE_BITSIZE (op_mode);
hv = HWI_SIGN_EXTEND (lv);
}
break;
case SQRT:
return 0;
default:
return 0;
}
return immed_double_const (lv, hv, mode);
}
else if (GET_CODE (op) == CONST_DOUBLE
&& SCALAR_FLOAT_MODE_P (mode))
{
REAL_VALUE_TYPE d, t;
REAL_VALUE_FROM_CONST_DOUBLE (d, op);
switch (code)
{
case SQRT:
if (HONOR_SNANS (mode) && real_isnan (&d))
return 0;
real_sqrt (&t, mode, &d);
d = t;
break;
case ABS:
d = REAL_VALUE_ABS (d);
break;
case NEG:
d = REAL_VALUE_NEGATE (d);
break;
case FLOAT_TRUNCATE:
d = real_value_truncate (mode, d);
break;
case FLOAT_EXTEND:
/* All this does is change the mode. */
break;
case FIX:
real_arithmetic (&d, FIX_TRUNC_EXPR, &d, NULL);
break;
case NOT:
{
long tmp[4];
int i;
real_to_target (tmp, &d, GET_MODE (op));
for (i = 0; i < 4; i++)
tmp[i] = ~tmp[i];
real_from_target (&d, tmp, mode);
break;
}
default:
gcc_unreachable ();
}
return CONST_DOUBLE_FROM_REAL_VALUE (d, mode);
}
else if (GET_CODE (op) == CONST_DOUBLE
&& SCALAR_FLOAT_MODE_P (GET_MODE (op))
&& GET_MODE_CLASS (mode) == MODE_INT
&& width <= 2*HOST_BITS_PER_WIDE_INT && width > 0)
{
/* Although the overflow semantics of RTL's FIX and UNSIGNED_FIX
operators are intentionally left unspecified (to ease implementation
by target backends), for consistency, this routine implements the
same semantics for constant folding as used by the middle-end. */
/* This was formerly used only for non-IEEE float.
eggert@twinsun.com says it is safe for IEEE also. */
HOST_WIDE_INT xh, xl, th, tl;
REAL_VALUE_TYPE x, t;
REAL_VALUE_FROM_CONST_DOUBLE (x, op);
switch (code)
{
case FIX:
if (REAL_VALUE_ISNAN (x))
return const0_rtx;
/* Test against the signed upper bound. */
if (width > HOST_BITS_PER_WIDE_INT)
{
th = ((unsigned HOST_WIDE_INT) 1
<< (width - HOST_BITS_PER_WIDE_INT - 1)) - 1;
tl = -1;
}
else
{
th = 0;
tl = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
}
real_from_integer (&t, VOIDmode, tl, th, 0);
if (REAL_VALUES_LESS (t, x))
{
xh = th;
xl = tl;
break;
}
/* Test against the signed lower bound. */
if (width > HOST_BITS_PER_WIDE_INT)
{
th = (HOST_WIDE_INT) -1 << (width - HOST_BITS_PER_WIDE_INT - 1);
tl = 0;
}
else
{
th = -1;
tl = (HOST_WIDE_INT) -1 << (width - 1);
}
real_from_integer (&t, VOIDmode, tl, th, 0);
if (REAL_VALUES_LESS (x, t))
{
xh = th;
xl = tl;
break;
}
REAL_VALUE_TO_INT (&xl, &xh, x);
break;
case UNSIGNED_FIX:
if (REAL_VALUE_ISNAN (x) || REAL_VALUE_NEGATIVE (x))
return const0_rtx;
/* Test against the unsigned upper bound. */
if (width == 2*HOST_BITS_PER_WIDE_INT)
{
th = -1;
tl = -1;
}
else if (width >= HOST_BITS_PER_WIDE_INT)
{
th = ((unsigned HOST_WIDE_INT) 1
<< (width - HOST_BITS_PER_WIDE_INT)) - 1;
tl = -1;
}
else
{
th = 0;
tl = ((unsigned HOST_WIDE_INT) 1 << width) - 1;
}
real_from_integer (&t, VOIDmode, tl, th, 1);
if (REAL_VALUES_LESS (t, x))
{
xh = th;
xl = tl;
break;
}
REAL_VALUE_TO_INT (&xl, &xh, x);
break;
default:
gcc_unreachable ();
}
return immed_double_const (xl, xh, mode);
}
return NULL_RTX;
}
/* Subroutine of simplify_binary_operation to simplify a commutative,
associative binary operation CODE with result mode MODE, operating
on OP0 and OP1. CODE is currently one of PLUS, MULT, AND, IOR, XOR,
SMIN, SMAX, UMIN or UMAX. Return zero if no simplification or
canonicalization is possible. */
static rtx
simplify_associative_operation (enum rtx_code code, enum machine_mode mode,
rtx op0, rtx op1)
{
rtx tem;
/* Linearize the operator to the left. */
if (GET_CODE (op1) == code)
{
/* "(a op b) op (c op d)" becomes "((a op b) op c) op d)". */
if (GET_CODE (op0) == code)
{
tem = simplify_gen_binary (code, mode, op0, XEXP (op1, 0));
return simplify_gen_binary (code, mode, tem, XEXP (op1, 1));
}
/* "a op (b op c)" becomes "(b op c) op a". */
if (! swap_commutative_operands_p (op1, op0))
return simplify_gen_binary (code, mode, op1, op0);
tem = op0;
op0 = op1;
op1 = tem;
}
if (GET_CODE (op0) == code)
{
/* Canonicalize "(x op c) op y" as "(x op y) op c". */
if (swap_commutative_operands_p (XEXP (op0, 1), op1))
{
tem = simplify_gen_binary (code, mode, XEXP (op0, 0), op1);
return simplify_gen_binary (code, mode, tem, XEXP (op0, 1));
}
/* Attempt to simplify "(a op b) op c" as "a op (b op c)". */
tem = simplify_binary_operation (code, mode, XEXP (op0, 1), op1);
if (tem != 0)
return simplify_gen_binary (code, mode, XEXP (op0, 0), tem);
/* Attempt to simplify "(a op b) op c" as "(a op c) op b". */
tem = simplify_binary_operation (code, mode, XEXP (op0, 0), op1);
if (tem != 0)
return simplify_gen_binary (code, mode, tem, XEXP (op0, 1));
}
return 0;
}
/* Simplify a binary operation CODE with result mode MODE, operating on OP0
and OP1. Return 0 if no simplification is possible.
Don't use this for relational operations such as EQ or LT.
Use simplify_relational_operation instead. */
rtx
simplify_binary_operation (enum rtx_code code, enum machine_mode mode,
rtx op0, rtx op1)
{
rtx trueop0, trueop1;
rtx tem;
/* Relational operations don't work here. We must know the mode
of the operands in order to do the comparison correctly.
Assuming a full word can give incorrect results.
Consider comparing 128 with -128 in QImode. */
gcc_assert (GET_RTX_CLASS (code) != RTX_COMPARE);
gcc_assert (GET_RTX_CLASS (code) != RTX_COMM_COMPARE);
/* Make sure the constant is second. */
if (GET_RTX_CLASS (code) == RTX_COMM_ARITH
&& swap_commutative_operands_p (op0, op1))
{
tem = op0, op0 = op1, op1 = tem;
}
trueop0 = avoid_constant_pool_reference (op0);
trueop1 = avoid_constant_pool_reference (op1);
tem = simplify_const_binary_operation (code, mode, trueop0, trueop1);
if (tem)
return tem;
return simplify_binary_operation_1 (code, mode, op0, op1, trueop0, trueop1);
}
/* Subroutine of simplify_binary_operation. Simplify a binary operation
CODE with result mode MODE, operating on OP0 and OP1. If OP0 and/or
OP1 are constant pool references, TRUEOP0 and TRUEOP1 represent the
actual constants. */
static rtx
simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode,
rtx op0, rtx op1, rtx trueop0, rtx trueop1)
{
rtx tem, reversed, opleft, opright;
HOST_WIDE_INT val;
unsigned int width = GET_MODE_BITSIZE (mode);
/* Even if we can't compute a constant result,
there are some cases worth simplifying. */
switch (code)
{
case PLUS:
/* Maybe simplify x + 0 to x. The two expressions are equivalent
when x is NaN, infinite, or finite and nonzero. They aren't
when x is -0 and the rounding mode is not towards -infinity,
since (-0) + 0 is then 0. */
if (!HONOR_SIGNED_ZEROS (mode) && trueop1 == CONST0_RTX (mode))
return op0;
/* ((-a) + b) -> (b - a) and similarly for (a + (-b)). These
transformations are safe even for IEEE. */
if (GET_CODE (op0) == NEG)
return simplify_gen_binary (MINUS, mode, op1, XEXP (op0, 0));
else if (GET_CODE (op1) == NEG)
return simplify_gen_binary (MINUS, mode, op0, XEXP (op1, 0));
/* (~a) + 1 -> -a */
if (INTEGRAL_MODE_P (mode)
&& GET_CODE (op0) == NOT
&& trueop1 == const1_rtx)
return simplify_gen_unary (NEG, mode, XEXP (op0, 0), mode);
/* Handle both-operands-constant cases. We can only add
CONST_INTs to constants since the sum of relocatable symbols
can't be handled by most assemblers. Don't add CONST_INT
to CONST_INT since overflow won't be computed properly if wider
than HOST_BITS_PER_WIDE_INT. */
if ((GET_CODE (op0) == CONST
|| GET_CODE (op0) == SYMBOL_REF
|| GET_CODE (op0) == LABEL_REF)
&& GET_CODE (op1) == CONST_INT)
return plus_constant (op0, INTVAL (op1));
else if ((GET_CODE (op1) == CONST
|| GET_CODE (op1) == SYMBOL_REF
|| GET_CODE (op1) == LABEL_REF)
&& GET_CODE (op0) == CONST_INT)
return plus_constant (op1, INTVAL (op0));
/* See if this is something like X * C - X or vice versa or
if the multiplication is written as a shift. If so, we can
distribute and make a new multiply, shift, or maybe just
have X (if C is 2 in the example above). But don't make
something more expensive than we had before. */
if (SCALAR_INT_MODE_P (mode))
{
HOST_WIDE_INT coeff0h = 0, coeff1h = 0;
unsigned HOST_WIDE_INT coeff0l = 1, coeff1l = 1;
rtx lhs = op0, rhs = op1;
if (GET_CODE (lhs) == NEG)
{
coeff0l = -1;
coeff0h = -1;
lhs = XEXP (lhs, 0);
}
else if (GET_CODE (lhs) == MULT
&& GET_CODE (XEXP (lhs, 1)) == CONST_INT)
{
coeff0l = INTVAL (XEXP (lhs, 1));
coeff0h = INTVAL (XEXP (lhs, 1)) < 0 ? -1 : 0;
lhs = XEXP (lhs, 0);
}
else if (GET_CODE (lhs) == ASHIFT
&& GET_CODE (XEXP (lhs, 1)) == CONST_INT
&& INTVAL (XEXP (lhs, 1)) >= 0
&& INTVAL (XEXP (lhs, 1)) < HOST_BITS_PER_WIDE_INT)
{
coeff0l = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1));
coeff0h = 0;
lhs = XEXP (lhs, 0);
}
if (GET_CODE (rhs) == NEG)
{
coeff1l = -1;
coeff1h = -1;
rhs = XEXP (rhs, 0);
}
else if (GET_CODE (rhs) == MULT
&& GET_CODE (XEXP (rhs, 1)) == CONST_INT)
{
coeff1l = INTVAL (XEXP (rhs, 1));
coeff1h = INTVAL (XEXP (rhs, 1)) < 0 ? -1 : 0;
rhs = XEXP (rhs, 0);
}
else if (GET_CODE (rhs) == ASHIFT
&& GET_CODE (XEXP (rhs, 1)) == CONST_INT
&& INTVAL (XEXP (rhs, 1)) >= 0
&& INTVAL (XEXP (rhs, 1)) < HOST_BITS_PER_WIDE_INT)
{
coeff1l = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1));
coeff1h = 0;
rhs = XEXP (rhs, 0);
}
if (rtx_equal_p (lhs, rhs))
{
rtx orig = gen_rtx_PLUS (mode, op0, op1);
rtx coeff;
unsigned HOST_WIDE_INT l;
HOST_WIDE_INT h;
bool speed = optimize_function_for_speed_p (cfun);
add_double (coeff0l, coeff0h, coeff1l, coeff1h, &l, &h);
coeff = immed_double_const (l, h, mode);
tem = simplify_gen_binary (MULT, mode, lhs, coeff);
return rtx_cost (tem, SET, speed) <= rtx_cost (orig, SET, speed)
? tem : 0;
}
}
/* (plus (xor X C1) C2) is (xor X (C1^C2)) if C2 is signbit. */
if ((GET_CODE (op1) == CONST_INT
|| GET_CODE (op1) == CONST_DOUBLE)
&& GET_CODE (op0) == XOR
&& (GET_CODE (XEXP (op0, 1)) == CONST_INT
|| GET_CODE (XEXP (op0, 1)) == CONST_DOUBLE)
&& mode_signbit_p (mode, op1))
return simplify_gen_binary (XOR, mode, XEXP (op0, 0),
simplify_gen_binary (XOR, mode, op1,
XEXP (op0, 1)));
/* Canonicalize (plus (mult (neg B) C) A) to (minus A (mult B C)). */
if (!HONOR_SIGN_DEPENDENT_ROUNDING (mode)
&& GET_CODE (op0) == MULT
&& GET_CODE (XEXP (op0, 0)) == NEG)
{
rtx in1, in2;
in1 = XEXP (XEXP (op0, 0), 0);
in2 = XEXP (op0, 1);
return simplify_gen_binary (MINUS, mode, op1,
simplify_gen_binary (MULT, mode,
in1, in2));
}
/* (plus (comparison A B) C) can become (neg (rev-comp A B)) if
C is 1 and STORE_FLAG_VALUE is -1 or if C is -1 and STORE_FLAG_VALUE
is 1. */
if (COMPARISON_P (op0)
&& ((STORE_FLAG_VALUE == -1 && trueop1 == const1_rtx)
|| (STORE_FLAG_VALUE == 1 && trueop1 == constm1_rtx))
&& (reversed = reversed_comparison (op0, mode)))
return
simplify_gen_unary (NEG, mode, reversed, mode);
/* If one of the operands is a PLUS or a MINUS, see if we can
simplify this by the associative law.
Don't use the associative law for floating point.
The inaccuracy makes it nonassociative,
and subtle programs can break if operations are associated. */
if (INTEGRAL_MODE_P (mode)
&& (plus_minus_operand_p (op0)
|| plus_minus_operand_p (op1))
&& (tem = simplify_plus_minus (code, mode, op0, op1)) != 0)
return tem;
/* Reassociate floating point addition only when the user
specifies associative math operations. */
if (FLOAT_MODE_P (mode)
&& flag_associative_math)
{
tem = simplify_associative_operation (code, mode, op0, op1);
if (tem)
return tem;
}
break;
case COMPARE:
#ifdef HAVE_cc0
/* Convert (compare FOO (const_int 0)) to FOO unless we aren't
using cc0, in which case we want to leave it as a COMPARE
so we can distinguish it from a register-register-copy.
In IEEE floating point, x-0 is not the same as x. */
if (!(HONOR_SIGNED_ZEROS (mode)
&& HONOR_SIGN_DEPENDENT_ROUNDING (mode))
&& trueop1 == CONST0_RTX (mode))
return op0;
#endif
/* Convert (compare (gt (flags) 0) (lt (flags) 0)) to (flags). */
if (((GET_CODE (op0) == GT && GET_CODE (op1) == LT)
|| (GET_CODE (op0) == GTU && GET_CODE (op1) == LTU))
&& XEXP (op0, 1) == const0_rtx && XEXP (op1, 1) == const0_rtx)
{
rtx xop00 = XEXP (op0, 0);
rtx xop10 = XEXP (op1, 0);
#ifdef HAVE_cc0
if (GET_CODE (xop00) == CC0 && GET_CODE (xop10) == CC0)
#else
if (REG_P (xop00) && REG_P (xop10)
&& GET_MODE (xop00) == GET_MODE (xop10)
&& REGNO (xop00) == REGNO (xop10)
&& GET_MODE_CLASS (GET_MODE (xop00)) == MODE_CC
&& GET_MODE_CLASS (GET_MODE (xop10)) == MODE_CC)
#endif
return xop00;
}
break;
case MINUS:
/* We can't assume x-x is 0 even with non-IEEE floating point,
but since it is zero except in very strange circumstances, we
will treat it as zero with -ffinite-math-only. */
if (rtx_equal_p (trueop0, trueop1)
&& ! side_effects_p (op0)
&& (!FLOAT_MODE_P (mode) || !HONOR_NANS (mode)))
return CONST0_RTX (mode);
/* Change subtraction from zero into negation. (0 - x) is the
same as -x when x is NaN, infinite, or finite and nonzero.
But if the mode has signed zeros, and does not round towards
-infinity, then 0 - 0 is 0, not -0. */
if (!HONOR_SIGNED_ZEROS (mode) && trueop0 == CONST0_RTX (mode))
return simplify_gen_unary (NEG, mode, op1, mode);
/* (-1 - a) is ~a. */
if (trueop0 == constm1_rtx)
return simplify_gen_unary (NOT, mode, op1, mode);
/* Subtracting 0 has no effect unless the mode has signed zeros
and supports rounding towards -infinity. In such a case,
0 - 0 is -0. */
if (!(HONOR_SIGNED_ZEROS (mode)
&& HONOR_SIGN_DEPENDENT_ROUNDING (mode))
&& trueop1 == CONST0_RTX (mode))
return op0;
/* See if this is something like X * C - X or vice versa or
if the multiplication is written as a shift. If so, we can
distribute and make a new multiply, shift, or maybe just
have X (if C is 2 in the example above). But don't make
something more expensive than we had before. */
if (SCALAR_INT_MODE_P (mode))
{
HOST_WIDE_INT coeff0h = 0, negcoeff1h = -1;
unsigned HOST_WIDE_INT coeff0l = 1, negcoeff1l = -1;
rtx lhs = op0, rhs = op1;
if (GET_CODE (lhs) == NEG)
{
coeff0l = -1;
coeff0h = -1;
lhs = XEXP (lhs, 0);
}
else if (GET_CODE (lhs) == MULT
&& GET_CODE (XEXP (lhs, 1)) == CONST_INT)
{
coeff0l = INTVAL (XEXP (lhs, 1));
coeff0h = INTVAL (XEXP (lhs, 1)) < 0 ? -1 : 0;
lhs = XEXP (lhs, 0);
}
else if (GET_CODE (lhs) == ASHIFT
&& GET_CODE (XEXP (lhs, 1)) == CONST_INT
&& INTVAL (XEXP (lhs, 1)) >= 0
&& INTVAL (XEXP (lhs, 1)) < HOST_BITS_PER_WIDE_INT)
{
coeff0l = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1));
coeff0h = 0;
lhs = XEXP (lhs, 0);
}
if (GET_CODE (rhs) == NEG)
{
negcoeff1l = 1;
negcoeff1h = 0;
rhs = XEXP (rhs, 0);
}
else if (GET_CODE (rhs) == MULT
&& GET_CODE (XEXP (rhs, 1)) == CONST_INT)
{
negcoeff1l = -INTVAL (XEXP (rhs, 1));
negcoeff1h = INTVAL (XEXP (rhs, 1)) <= 0 ? 0 : -1;
rhs = XEXP (rhs, 0);
}
else if (GET_CODE (rhs) == ASHIFT
&& GET_CODE (XEXP (rhs, 1)) == CONST_INT
&& INTVAL (XEXP (rhs, 1)) >= 0
&& INTVAL (XEXP (rhs, 1)) < HOST_BITS_PER_WIDE_INT)
{
negcoeff1l = -(((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1)));
negcoeff1h = -1;
rhs = XEXP (rhs, 0);
}
if (rtx_equal_p (lhs, rhs))
{
rtx orig = gen_rtx_MINUS (mode, op0, op1);
rtx coeff;
unsigned HOST_WIDE_INT l;
HOST_WIDE_INT h;
bool speed = optimize_function_for_speed_p (cfun);
add_double (coeff0l, coeff0h, negcoeff1l, negcoeff1h, &l, &h);
coeff = immed_double_const (l, h, mode);
tem = simplify_gen_binary (MULT, mode, lhs, coeff);
return rtx_cost (tem, SET, speed) <= rtx_cost (orig, SET, speed)
? tem : 0;
}
}
/* (a - (-b)) -> (a + b). True even for IEEE. */
if (GET_CODE (op1) == NEG)
return simplify_gen_binary (PLUS, mode, op0, XEXP (op1, 0));
/* (-x - c) may be simplified as (-c - x). */
if (GET_CODE (op0) == NEG
&& (GET_CODE (op1) == CONST_INT
|| GET_CODE (op1) == CONST_DOUBLE))
{
tem = simplify_unary_operation (NEG, mode, op1, mode);
if (tem)
return simplify_gen_binary (MINUS, mode, tem, XEXP (op0, 0));
}
/* Don't let a relocatable value get a negative coeff. */
if (GET_CODE (op1) == CONST_INT && GET_MODE (op0) != VOIDmode)
return simplify_gen_binary (PLUS, mode,
op0,
neg_const_int (mode, op1));
/* (x - (x & y)) -> (x & ~y) */
if (GET_CODE (op1) == AND)
{
if (rtx_equal_p (op0, XEXP (op1, 0)))
{
tem = simplify_gen_unary (NOT, mode, XEXP (op1, 1),
GET_MODE (XEXP (op1, 1)));
return simplify_gen_binary (AND, mode, op0, tem);
}
if (rtx_equal_p (op0, XEXP (op1, 1)))
{
tem = simplify_gen_unary (NOT, mode, XEXP (op1, 0),
GET_MODE (XEXP (op1, 0)));
return simplify_gen_binary (AND, mode, op0, tem);
}
}
/* If STORE_FLAG_VALUE is 1, (minus 1 (comparison foo bar)) can be done
by reversing the comparison code if valid. */
if (STORE_FLAG_VALUE == 1
&& trueop0 == const1_rtx
&& COMPARISON_P (op1)
&& (reversed = reversed_comparison (op1, mode)))
return reversed;
/* Canonicalize (minus A (mult (neg B) C)) to (plus (mult B C) A). */
if (!HONOR_SIGN_DEPENDENT_ROUNDING (mode)
&& GET_CODE (op1) == MULT
&& GET_CODE (XEXP (op1, 0)) == NEG)
{
rtx in1, in2;
in1 = XEXP (XEXP (op1, 0), 0);
in2 = XEXP (op1, 1);
return simplify_gen_binary (PLUS, mode,
simplify_gen_binary (MULT, mode,
in1, in2),
op0);
}
/* Canonicalize (minus (neg A) (mult B C)) to
(minus (mult (neg B) C) A). */
if (!HONOR_SIGN_DEPENDENT_ROUNDING (mode)
&& GET_CODE (op1) == MULT
&& GET_CODE (op0) == NEG)
{
rtx in1, in2;
in1 = simplify_gen_unary (NEG, mode, XEXP (op1, 0), mode);
in2 = XEXP (op1, 1);
return simplify_gen_binary (MINUS, mode,
simplify_gen_binary (MULT, mode,
in1, in2),
XEXP (op0, 0));
}
/* If one of the operands is a PLUS or a MINUS, see if we can
simplify this by the associative law. This will, for example,
canonicalize (minus A (plus B C)) to (minus (minus A B) C).
Don't use the associative law for floating point.
The inaccuracy makes it nonassociative,
and subtle programs can break if operations are associated. */
if (INTEGRAL_MODE_P (mode)
&& (plus_minus_operand_p (op0)
|| plus_minus_operand_p (op1))
&& (tem = simplify_plus_minus (code, mode, op0, op1)) != 0)
return tem;
break;
case MULT:
if (trueop1 == constm1_rtx)
return simplify_gen_unary (NEG, mode, op0, mode);
/* Maybe simplify x * 0 to 0. The reduction is not valid if
x is NaN, since x * 0 is then also NaN. Nor is it valid
when the mode has signed zeros, since multiplying a negative
number by 0 will give -0, not 0. */
if (!HONOR_NANS (mode)
&& !HONOR_SIGNED_ZEROS (mode)
&& trueop1 == CONST0_RTX (mode)
&& ! side_effects_p (op0))
return op1;
/* In IEEE floating point, x*1 is not equivalent to x for
signalling NaNs. */
if (!HONOR_SNANS (mode)
&& trueop1 == CONST1_RTX (mode))
return op0;
/* Convert multiply by constant power of two into shift unless
we are still generating RTL. This test is a kludge. */
if (GET_CODE (trueop1) == CONST_INT
&& (val = exact_log2 (INTVAL (trueop1))) >= 0
/* If the mode is larger than the host word size, and the
uppermost bit is set, then this isn't a power of two due
to implicit sign extension. */
&& (width <= HOST_BITS_PER_WIDE_INT
|| val != HOST_BITS_PER_WIDE_INT - 1))
return simplify_gen_binary (ASHIFT, mode, op0, GEN_INT (val));
/* Likewise for multipliers wider than a word. */
if (GET_CODE (trueop1) == CONST_DOUBLE
&& (GET_MODE (trueop1) == VOIDmode
|| GET_MODE_CLASS (GET_MODE (trueop1)) == MODE_INT)
&& GET_MODE (op0) == mode
&& CONST_DOUBLE_LOW (trueop1) == 0
&& (val = exact_log2 (CONST_DOUBLE_HIGH (trueop1))) >= 0)
return simplify_gen_binary (ASHIFT, mode, op0,
GEN_INT (val + HOST_BITS_PER_WIDE_INT));
/* x*2 is x+x and x*(-1) is -x */
if (GET_CODE (trueop1) == CONST_DOUBLE
&& SCALAR_FLOAT_MODE_P (GET_MODE (trueop1))
&& !DECIMAL_FLOAT_MODE_P (GET_MODE (trueop1))
&& GET_MODE (op0) == mode)
{
REAL_VALUE_TYPE d;
REAL_VALUE_FROM_CONST_DOUBLE (d, trueop1);
if (REAL_VALUES_EQUAL (d, dconst2))
return simplify_gen_binary (PLUS, mode, op0, copy_rtx (op0));
if (!HONOR_SNANS (mode)
&& REAL_VALUES_EQUAL (d, dconstm1))
return simplify_gen_unary (NEG, mode, op0, mode);
}
/* Optimize -x * -x as x * x. */
if (FLOAT_MODE_P (mode)
&& GET_CODE (op0) == NEG
&& GET_CODE (op1) == NEG
&& rtx_equal_p (XEXP (op0, 0), XEXP (op1, 0))
&& !side_effects_p (XEXP (op0, 0)))
return simplify_gen_binary (MULT, mode, XEXP (op0, 0), XEXP (op1, 0));
/* Likewise, optimize abs(x) * abs(x) as x * x. */
if (SCALAR_FLOAT_MODE_P (mode)
&& GET_CODE (op0) == ABS
&& GET_CODE (op1) == ABS
&& rtx_equal_p (XEXP (op0, 0), XEXP (op1, 0))
&& !side_effects_p (XEXP (op0, 0)))
return simplify_gen_binary (MULT, mode, XEXP (op0, 0), XEXP (op1, 0));
/* Reassociate multiplication, but for floating point MULTs
only when the user specifies unsafe math optimizations. */
if (! FLOAT_MODE_P (mode)
|| flag_unsafe_math_optimizations)
{
tem = simplify_associative_operation (code, mode, op0, op1);
if (tem)
return tem;
}
break;
case IOR:
if (trueop1 == const0_rtx)
return op0;
if (GET_CODE (trueop1) == CONST_INT
&& ((INTVAL (trueop1) & GET_MODE_MASK (mode))
== GET_MODE_MASK (mode)))
return op1;
if (rtx_equal_p (trueop0, trueop1) && ! side_effects_p (op0))
return op0;
/* A | (~A) -> -1 */
if (((GET_CODE (op0) == NOT && rtx_equal_p (XEXP (op0, 0), op1))
|| (GET_CODE (op1) == NOT && rtx_equal_p (XEXP (op1, 0), op0)))
&& ! side_effects_p (op0)
&& SCALAR_INT_MODE_P (mode))
return constm1_rtx;
/* (ior A C) is C if all bits of A that might be nonzero are on in C. */
if (GET_CODE (op1) == CONST_INT
&& GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
&& (nonzero_bits (op0, mode) & ~INTVAL (op1)) == 0)
return op1;
/* Canonicalize (X & C1) | C2. */
if (GET_CODE (op0) == AND
&& GET_CODE (trueop1) == CONST_INT
&& GET_CODE (XEXP (op0, 1)) == CONST_INT)
{
HOST_WIDE_INT mask = GET_MODE_MASK (mode);
HOST_WIDE_INT c1 = INTVAL (XEXP (op0, 1));
HOST_WIDE_INT c2 = INTVAL (trueop1);
/* If (C1&C2) == C1, then (X&C1)|C2 becomes X. */
if ((c1 & c2) == c1
&& !side_effects_p (XEXP (op0, 0)))
return trueop1;
/* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
if (((c1|c2) & mask) == mask)
return simplify_gen_binary (IOR, mode, XEXP (op0, 0), op1);
/* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2. */
if (((c1 & ~c2) & mask) != (c1 & mask))
{
tem = simplify_gen_binary (AND, mode, XEXP (op0, 0),
gen_int_mode (c1 & ~c2, mode));
return simplify_gen_binary (IOR, mode, tem, op1);
}
}
/* Convert (A & B) | A to A. */
if (GET_CODE (op0) == AND
&& (rtx_equal_p (XEXP (op0, 0), op1)
|| rtx_equal_p (XEXP (op0, 1), op1))
&& ! side_effects_p (XEXP (op0, 0))
&& ! side_effects_p (XEXP (op0, 1)))
return op1;
/* Convert (ior (ashift A CX) (lshiftrt A CY)) where CX+CY equals the
mode size to (rotate A CX). */
if (GET_CODE (op1) == ASHIFT
|| GET_CODE (op1) == SUBREG)
{
opleft = op1;
opright = op0;
}
else
{
opright = op1;
opleft = op0;
}
if (GET_CODE (opleft) == ASHIFT && GET_CODE (opright) == LSHIFTRT
&& rtx_equal_p (XEXP (opleft, 0), XEXP (opright, 0))
&& GET_CODE (XEXP (opleft, 1)) == CONST_INT
&& GET_CODE (XEXP (opright, 1)) == CONST_INT
&& (INTVAL (XEXP (opleft, 1)) + INTVAL (XEXP (opright, 1))
== GET_MODE_BITSIZE (mode)))
return gen_rtx_ROTATE (mode, XEXP (opright, 0), XEXP (opleft, 1));
/* Same, but for ashift that has been "simplified" to a wider mode
by simplify_shift_const. */
if (GET_CODE (opleft) == SUBREG
&& GET_CODE (SUBREG_REG (opleft)) == ASHIFT
&& GET_CODE (opright) == LSHIFTRT
&& GET_CODE (XEXP (opright, 0)) == SUBREG
&& GET_MODE (opleft) == GET_MODE (XEXP (opright, 0))
&& SUBREG_BYTE (opleft) == SUBREG_BYTE (XEXP (opright, 0))
&& (GET_MODE_SIZE (GET_MODE (opleft))
< GET_MODE_SIZE (GET_MODE (SUBREG_REG (opleft))))
&& rtx_equal_p (XEXP (SUBREG_REG (opleft), 0),
SUBREG_REG (XEXP (opright, 0)))
&& GET_CODE (XEXP (SUBREG_REG (opleft), 1)) == CONST_INT
&& GET_CODE (XEXP (opright, 1)) == CONST_INT
&& (INTVAL (XEXP (SUBREG_REG (opleft), 1)) + INTVAL (XEXP (opright, 1))
== GET_MODE_BITSIZE (mode)))
return gen_rtx_ROTATE (mode, XEXP (opright, 0),
XEXP (SUBREG_REG (opleft), 1));
/* If we have (ior (and (X C1) C2)), simplify this by making
C1 as small as possible if C1 actually changes. */
if (GET_CODE (op1) == CONST_INT
&& (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
|| INTVAL (op1) > 0)
&& GET_CODE (op0) == AND
&& GET_CODE (XEXP (op0, 1)) == CONST_INT
&& GET_CODE (op1) == CONST_INT
&& (INTVAL (XEXP (op0, 1)) & INTVAL (op1)) != 0)
return simplify_gen_binary (IOR, mode,
simplify_gen_binary
(AND, mode, XEXP (op0, 0),
GEN_INT (INTVAL (XEXP (op0, 1))
& ~INTVAL (op1))),
op1);
/* If OP0 is (ashiftrt (plus ...) C), it might actually be
a (sign_extend (plus ...)). Then check if OP1 is a CONST_INT and
the PLUS does not affect any of the bits in OP1: then we can do
the IOR as a PLUS and we can associate. This is valid if OP1
can be safely shifted left C bits. */
if (GET_CODE (trueop1) == CONST_INT && GET_CODE (op0) == ASHIFTRT
&& GET_CODE (XEXP (op0, 0)) == PLUS
&& GET_CODE (XEXP (XEXP (op0, 0), 1)) == CONST_INT
&& GET_CODE (XEXP (op0, 1)) == CONST_INT
&& INTVAL (XEXP (op0, 1)) < HOST_BITS_PER_WIDE_INT)
{
int count = INTVAL (XEXP (op0, 1));
HOST_WIDE_INT mask = INTVAL (trueop1) << count;
if (mask >> count == INTVAL (trueop1)
&& (mask & nonzero_bits (XEXP (op0, 0), mode)) == 0)
return simplify_gen_binary (ASHIFTRT, mode,
plus_constant (XEXP (op0, 0), mask),
XEXP (op0, 1));
}
tem = simplify_associative_operation (code, mode, op0, op1);
if (tem)
return tem;
break;
case XOR:
if (trueop1 == const0_rtx)
return op0;
if (GET_CODE (trueop1) == CONST_INT
&& ((INTVAL (trueop1) & GET_MODE_MASK (mode))
== GET_MODE_MASK (mode)))
return simplify_gen_unary (NOT, mode, op0, mode);
if (rtx_equal_p (trueop0, trueop1)
&& ! side_effects_p (op0)
&& GET_MODE_CLASS (mode) != MODE_CC)
return CONST0_RTX (mode);
/* Canonicalize XOR of the most significant bit to PLUS. */
if ((GET_CODE (op1) == CONST_INT
|| GET_CODE (op1) == CONST_DOUBLE)
&& mode_signbit_p (mode, op1))
return simplify_gen_binary (PLUS, mode, op0, op1);
/* (xor (plus X C1) C2) is (xor X (C1^C2)) if C1 is signbit. */
if ((GET_CODE (op1) == CONST_INT
|| GET_CODE (op1) == CONST_DOUBLE)
&& GET_CODE (op0) == PLUS
&& (GET_CODE (XEXP (op0, 1)) == CONST_INT
|| GET_CODE (XEXP (op0, 1)) == CONST_DOUBLE)
&& mode_signbit_p (mode, XEXP (op0, 1)))
return simplify_gen_binary (XOR, mode, XEXP (op0, 0),
simplify_gen_binary (XOR, mode, op1,
XEXP (op0, 1)));
/* If we are XORing two things that have no bits in common,
convert them into an IOR. This helps to detect rotation encoded
using those methods and possibly other simplifications. */
if (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
&& (nonzero_bits (op0, mode)
& nonzero_bits (op1, mode)) == 0)
return (simplify_gen_binary (IOR, mode, op0, op1));
/* Convert (XOR (NOT x) (NOT y)) to (XOR x y).
Also convert (XOR (NOT x) y) to (NOT (XOR x y)), similarly for
(NOT y). */
{
int num_negated = 0;
if (GET_CODE (op0) == NOT)
num_negated++, op0 = XEXP (op0, 0);
if (GET_CODE (op1) == NOT)
num_negated++, op1 = XEXP (op1, 0);
if (num_negated == 2)
return simplify_gen_binary (XOR, mode, op0, op1);
else if (num_negated == 1)
return simplify_gen_unary (NOT, mode,
simplify_gen_binary (XOR, mode, op0, op1),
mode);
}
/* Convert (xor (and A B) B) to (and (not A) B). The latter may
correspond to a machine insn or result in further simplifications
if B is a constant. */
if (GET_CODE (op0) == AND
&& rtx_equal_p (XEXP (op0, 1), op1)
&& ! side_effects_p (op1))
return simplify_gen_binary (AND, mode,
simplify_gen_unary (NOT, mode,
XEXP (op0, 0), mode),
op1);
else if (GET_CODE (op0) == AND
&& rtx_equal_p (XEXP (op0, 0), op1)
&& ! side_effects_p (op1))
return simplify_gen_binary (AND, mode,
simplify_gen_unary (NOT, mode,
XEXP (op0, 1), mode),
op1);
/* (xor (comparison foo bar) (const_int 1)) can become the reversed
comparison if STORE_FLAG_VALUE is 1. */
if (STORE_FLAG_VALUE == 1
&& trueop1 == const1_rtx
&& COMPARISON_P (op0)
&& (reversed = reversed_comparison (op0, mode)))
return reversed;
/* (lshiftrt foo C) where C is the number of bits in FOO minus 1
is (lt foo (const_int 0)), so we can perform the above
simplification if STORE_FLAG_VALUE is 1. */
if (STORE_FLAG_VALUE == 1
&& trueop1 == const1_rtx
&& GET_CODE (op0) == LSHIFTRT
&& GET_CODE (XEXP (op0, 1)) == CONST_INT
&& INTVAL (XEXP (op0, 1)) == GET_MODE_BITSIZE (mode) - 1)
return gen_rtx_GE (mode, XEXP (op0, 0), const0_rtx);
/* (xor (comparison foo bar) (const_int sign-bit))
when STORE_FLAG_VALUE is the sign bit. */
if (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
&& ((STORE_FLAG_VALUE & GET_MODE_MASK (mode))
== (unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (mode) - 1))
&& trueop1 == const_true_rtx
&& COMPARISON_P (op0)
&& (reversed = reversed_comparison (op0, mode)))
return reversed;
tem = simplify_associative_operation (code, mode, op0, op1);
if (tem)
return tem;
break;
case AND:
if (trueop1 == CONST0_RTX (mode) && ! side_effects_p (op0))
return trueop1;
if (GET_CODE (trueop1) == CONST_INT
&& GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT)
{
HOST_WIDE_INT nzop0 = nonzero_bits (trueop0, mode);
HOST_WIDE_INT val1 = INTVAL (trueop1);
/* If we are turning off bits already known off in OP0, we need
not do an AND. */
if ((nzop0 & ~val1) == 0)
return op0;
/* If we are clearing all the nonzero bits, the result is zero. */
if ((val1 & nzop0) == 0 && !side_effects_p (op0))
return CONST0_RTX (mode);
}
if (rtx_equal_p (trueop0, trueop1) && ! side_effects_p (op0)
&& GET_MODE_CLASS (mode) != MODE_CC)
return op0;
/* A & (~A) -> 0 */
if (((GET_CODE (op0) == NOT && rtx_equal_p (XEXP (op0, 0), op1))
|| (GET_CODE (op1) == NOT && rtx_equal_p (XEXP (op1, 0), op0)))
&& ! side_effects_p (op0)
&& GET_MODE_CLASS (mode) != MODE_CC)
return CONST0_RTX (mode);
/* Transform (and (extend X) C) into (zero_extend (and X C)) if
there are no nonzero bits of C outside of X's mode. */
if ((GET_CODE (op0) == SIGN_EXTEND
|| GET_CODE (op0) == ZERO_EXTEND)
&& GET_CODE (trueop1) == CONST_INT
&& GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
&& (~GET_MODE_MASK (GET_MODE (XEXP (op0, 0)))
& INTVAL (trueop1)) == 0)
{
enum machine_mode imode = GET_MODE (XEXP (op0, 0));
tem = simplify_gen_binary (AND, imode, XEXP (op0, 0),
gen_int_mode (INTVAL (trueop1),
imode));
return simplify_gen_unary (ZERO_EXTEND, mode, tem, imode);
}
/* Canonicalize (A | C1) & C2 as (A & C2) | (C1 & C2). */
if (GET_CODE (op0) == IOR
&& GET_CODE (trueop1) == CONST_INT
&& GET_CODE (XEXP (op0, 1)) == CONST_INT)
{
HOST_WIDE_INT tmp = INTVAL (trueop1) & INTVAL (XEXP (op0, 1));
return simplify_gen_binary (IOR, mode,
simplify_gen_binary (AND, mode,
XEXP (op0, 0), op1),
gen_int_mode (tmp, mode));
}
/* Convert (A ^ B) & A to A & (~B) since the latter is often a single
insn (and may simplify more). */
if (GET_CODE (op0) == XOR
&& rtx_equal_p (XEXP (op0, 0), op1)
&& ! side_effects_p (op1))
return simplify_gen_binary (AND, mode,
simplify_gen_unary (NOT, mode,
XEXP (op0, 1), mode),
op1);
if (GET_CODE (op0) == XOR
&& rtx_equal_p (XEXP (op0, 1), op1)
&& ! side_effects_p (op1))
return simplify_gen_binary (AND, mode,
simplify_gen_unary (NOT, mode,
XEXP (op0, 0), mode),
op1);
/* Similarly for (~(A ^ B)) & A. */
if (GET_CODE (op0) == NOT
&& GET_CODE (XEXP (op0, 0)) == XOR
&& rtx_equal_p (XEXP (XEXP (op0, 0), 0), op1)
&& ! side_effects_p (op1))
return simplify_gen_binary (AND, mode, XEXP (XEXP (op0, 0), 1), op1);
if (GET_CODE (op0) == NOT
&& GET_CODE (XEXP (op0, 0)) == XOR
&& rtx_equal_p (XEXP (XEXP (op0, 0), 1), op1)
&& ! side_effects_p (op1))
return simplify_gen_binary (AND, mode, XEXP (XEXP (op0, 0), 0), op1);
/* Convert (A | B) & A to A. */
if (GET_CODE (op0) == IOR
&& (rtx_equal_p (XEXP (op0, 0), op1)
|| rtx_equal_p (XEXP (op0, 1), op1))
&& ! side_effects_p (XEXP (op0, 0))
&& ! side_effects_p (XEXP (op0, 1)))
return op1;
/* For constants M and N, if M == (1LL << cst) - 1 && (N & M) == M,
((A & N) + B) & M -> (A + B) & M
Similarly if (N & M) == 0,
((A | N) + B) & M -> (A + B) & M
and for - instead of + and/or ^ instead of |.
Also, if (N & M) == 0, then
(A +- N) & M -> A & M. */
if (GET_CODE (trueop1) == CONST_INT
&& GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
&& ~INTVAL (trueop1)
&& (INTVAL (trueop1) & (INTVAL (trueop1) + 1)) == 0
&& (GET_CODE (op0) == PLUS || GET_CODE (op0) == MINUS))
{
rtx pmop[2];
int which;
pmop[0] = XEXP (op0, 0);
pmop[1] = XEXP (op0, 1);
if (GET_CODE (pmop[1]) == CONST_INT
&& (INTVAL (pmop[1]) & INTVAL (trueop1)) == 0)
return simplify_gen_binary (AND, mode, pmop[0], op1);
for (which = 0; which < 2; which++)
{
tem = pmop[which];
switch (GET_CODE (tem))
{
case AND:
if (GET_CODE (XEXP (tem, 1)) == CONST_INT
&& (INTVAL (XEXP (tem, 1)) & INTVAL (trueop1))
== INTVAL (trueop1))
pmop[which] = XEXP (tem, 0);
break;
case IOR:
case XOR:
if (GET_CODE (XEXP (tem, 1)) == CONST_INT
&& (INTVAL (XEXP (tem, 1)) & INTVAL (trueop1)) == 0)
pmop[which] = XEXP (tem, 0);
break;
default:
break;
}
}
if (pmop[0] != XEXP (op0, 0) || pmop[1] != XEXP (op0, 1))
{
tem = simplify_gen_binary (GET_CODE (op0), mode,
pmop[0], pmop[1]);
return simplify_gen_binary (code, mode, tem, op1);
}
}
/* (and X (ior (not X) Y) -> (and X Y) */
if (GET_CODE (op1) == IOR
&& GET_CODE (XEXP (op1, 0)) == NOT
&& op0 == XEXP (XEXP (op1, 0), 0))
return simplify_gen_binary (AND, mode, op0, XEXP (op1, 1));
/* (and (ior (not X) Y) X) -> (and X Y) */
if (GET_CODE (op0) == IOR
&& GET_CODE (XEXP (op0, 0)) == NOT
&& op1 == XEXP (XEXP (op0, 0), 0))
return simplify_gen_binary (AND, mode, op1, XEXP (op0, 1));
tem = simplify_associative_operation (code, mode, op0, op1);
if (tem)
return tem;
break;
case UDIV:
/* 0/x is 0 (or x&0 if x has side-effects). */
if (trueop0 == CONST0_RTX (mode))
{
if (side_effects_p (op1))
return simplify_gen_binary (AND, mode, op1, trueop0);
return trueop0;
}
/* x/1 is x. */
if (trueop1 == CONST1_RTX (mode))
return rtl_hooks.gen_lowpart_no_emit (mode, op0);
/* Convert divide by power of two into shift. */
if (GET_CODE (trueop1) == CONST_INT
&& (val = exact_log2 (INTVAL (trueop1))) > 0)
return simplify_gen_binary (LSHIFTRT, mode, op0, GEN_INT (val));
break;
case DIV:
/* Handle floating point and integers separately. */
if (SCALAR_FLOAT_MODE_P (mode))
{
/* Maybe change 0.0 / x to 0.0. This transformation isn't
safe for modes with NaNs, since 0.0 / 0.0 will then be
NaN rather than 0.0. Nor is it safe for modes with signed
zeros, since dividing 0 by a negative number gives -0.0 */
if (trueop0 == CONST0_RTX (mode)
&& !HONOR_NANS (mode)
&& !HONOR_SIGNED_ZEROS (mode)
&& ! side_effects_p (op1))
return op0;
/* x/1.0 is x. */
if (trueop1 == CONST1_RTX (mode)
&& !HONOR_SNANS (mode))
return op0;
if (GET_CODE (trueop1) == CONST_DOUBLE
&& trueop1 != CONST0_RTX (mode))
{
REAL_VALUE_TYPE d;
REAL_VALUE_FROM_CONST_DOUBLE (d, trueop1);
/* x/-1.0 is -x. */
if (REAL_VALUES_EQUAL (d, dconstm1)
&& !HONOR_SNANS (mode))
return simplify_gen_unary (NEG, mode, op0, mode);
/* Change FP division by a constant into multiplication.
Only do this with -freciprocal-math. */
if (flag_reciprocal_math
&& !REAL_VALUES_EQUAL (d, dconst0))
{
REAL_ARITHMETIC (d, RDIV_EXPR, dconst1, d);
tem = CONST_DOUBLE_FROM_REAL_VALUE (d, mode);
return simplify_gen_binary (MULT, mode, op0, tem);
}
}
}
else
{
/* 0/x is 0 (or x&0 if x has side-effects). */
if (trueop0 == CONST0_RTX (mode))
{
if (side_effects_p (op1))
return simplify_gen_binary (AND, mode, op1, trueop0);
return trueop0;
}
/* x/1 is x. */
if (trueop1 == CONST1_RTX (mode))
return rtl_hooks.gen_lowpart_no_emit (mode, op0);
/* x/-1 is -x. */
if (trueop1 == constm1_rtx)
{
rtx x = rtl_hooks.gen_lowpart_no_emit (mode, op0);
return simplify_gen_unary (NEG, mode, x, mode);
}