/* 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 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
+ 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 2, or (at your option) any later
+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
for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
-02110-1301, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#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, rtx);
-static bool plus_minus_operand_p (rtx);
-static int simplify_plus_minus_op_data_cmp (const void *, const void *);
+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);
/* 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, rtx i)
+neg_const_int (enum machine_mode mode, const_rtx i)
{
return gen_int_mode (- INTVAL (i), mode);
}
the most significant bit of machine mode MODE. */
bool
-mode_signbit_p (enum machine_mode mode, rtx x)
+mode_signbit_p (enum machine_mode mode, const_rtx x)
{
unsigned HOST_WIDE_INT val;
unsigned int width;
{
rtx 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;
-
/* 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);
}
\f
return x;
}
+ if (GET_MODE (x) == BLKmode)
+ return x;
+
addr = XEXP (x, 0);
/* Call target hook to avoid the effects of -fpic etc.... */
return x;
}
-
-/* Return true if X is a MEM referencing the constant pool. */
-
-bool
-constant_pool_reference_p (rtx x)
-{
- return avoid_constant_pool_reference (x) != x;
-}
\f
/* Make a unary operation by first seeing if it folds and otherwise making
the specified operation. */
resulting RTX. Return a new RTX which is as simplified as possible. */
rtx
-simplify_replace_rtx (rtx x, rtx old_rtx, rtx new_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);
&& 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)
+ {
+ 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:
return simplify_gen_unary (GET_CODE (op), mode,
XEXP (XEXP (op, 0), 0), mode);
- /* (truncate:SI (subreg:DI (truncate:SI X) 0)) is
- (truncate:SI x). */
+ /* (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 SUBREG_REG (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 if TRULY_NOOP_TRUNCATION
- is nonzero for the corresponding modes. 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),
+ 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 (mode) + 1)
+ ? (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);
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)
/* (float_truncate (float x)) is (float x) */
if (GET_CODE (op) == FLOAT
&& (flag_unsafe_math_optimizations
- || ((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)))))))
+ || (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)));
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
*/
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),
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:
- /* (pop* (zero_extend <X>)) = (pop* <X>) */
- if (GET_CODE (op) == ZERO_EXTEND)
- return simplify_gen_unary (code, mode, XEXP (op, 0),
- GET_MODE (XEXP (op, 0)));
+ 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:
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 FLOAT_TRUNCATE:
case SS_TRUNCATE:
case US_TRUNCATE:
+ case SS_NEG:
return 0;
default:
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;
}
/* Attempt to simplify "(a op b) op c" as "a op (b op c)". */
- tem = swap_commutative_operands_p (XEXP (op0, 1), op1)
- ? simplify_binary_operation (code, mode, op1, XEXP (op0, 1))
- : simplify_binary_operation (code, mode, XEXP (op0, 1), op1);
+ 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 = swap_commutative_operands_p (XEXP (op0, 0), op1)
- ? simplify_binary_operation (code, mode, op1, XEXP (op0, 0))
- : simplify_binary_operation (code, mode, XEXP (op0, 0), op1);
+ tem = simplify_binary_operation (code, mode, XEXP (op0, 0), op1);
if (tem != 0)
return simplify_gen_binary (code, mode, tem, XEXP (op0, 1));
}
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)
XEXP (op0, 1)));
/* Canonicalize (plus (mult (neg B) C) A) to (minus A (mult B C)). */
- if (GET_CODE (op0) == MULT
+ if (!HONOR_SIGN_DEPENDENT_ROUNDING (mode)
+ && GET_CODE (op0) == MULT
&& GET_CODE (XEXP (op0, 0)) == NEG)
{
rtx in1, in2;
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 -funsafe-math-optimizations. */
+ will treat it as zero with -funsafe-math-optimizations and
+ -ffinite-math-only. */
if (rtx_equal_p (trueop0, trueop1)
&& ! side_effects_p (op0)
- && (! FLOAT_MODE_P (mode) || flag_unsafe_math_optimizations))
+ && (! FLOAT_MODE_P (mode)
+ || (flag_unsafe_math_optimizations
+ && !HONOR_NANS (mode)
+ && !HONOR_INFINITIES (mode))))
return CONST0_RTX (mode);
/* Change subtraction from zero into negation. (0 - x) is the
return reversed;
/* Canonicalize (minus A (mult (neg B) C)) to (plus (mult B C) A). */
- if (GET_CODE (op1) == MULT
+ if (!HONOR_SIGN_DEPENDENT_ROUNDING (mode)
+ && GET_CODE (op1) == MULT
&& GET_CODE (XEXP (op1, 0)) == NEG)
{
rtx in1, in2;
/* Canonicalize (minus (neg A) (mult B C)) to
(minus (mult (neg B) C) A). */
- if (GET_CODE (op1) == MULT
+ if (!HONOR_SIGN_DEPENDENT_ROUNDING (mode)
+ && GET_CODE (op1) == MULT
&& GET_CODE (op0) == NEG)
{
rtx in1, in2;
return simplify_gen_binary (ASHIFT, mode, op0, GEN_INT (val));
/* Likewise for multipliers wider than a word. */
- else 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)
+ 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));
if (REAL_VALUES_EQUAL (d, dconst2))
return simplify_gen_binary (PLUS, mode, op0, copy_rtx (op0));
- if (REAL_VALUES_EQUAL (d, dconstm1))
+ 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)
&& (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)
&& (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 (opright), 1));
+ 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. */
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
case ROTATERT:
case ROTATE:
case ASHIFTRT:
+ if (trueop1 == CONST0_RTX (mode))
+ return op0;
+ if (trueop0 == CONST0_RTX (mode) && ! side_effects_p (op1))
+ return op0;
/* Rotating ~0 always results in ~0. */
if (GET_CODE (trueop0) == CONST_INT && width <= HOST_BITS_PER_WIDE_INT
&& (unsigned HOST_WIDE_INT) INTVAL (trueop0) == GET_MODE_MASK (mode)
&& ! side_effects_p (op1))
return op0;
-
- /* Fall through.... */
+ break;
case ASHIFT:
+ case SS_ASHIFT:
+ if (trueop1 == CONST0_RTX (mode))
+ return op0;
+ if (trueop0 == CONST0_RTX (mode) && ! side_effects_p (op1))
+ return op0;
+ break;
+
case LSHIFTRT:
if (trueop1 == CONST0_RTX (mode))
return op0;
if (trueop0 == CONST0_RTX (mode) && ! side_effects_p (op1))
return op0;
+ /* Optimize (lshiftrt (clz X) C) as (eq X 0). */
+ if (GET_CODE (op0) == CLZ
+ && GET_CODE (trueop1) == CONST_INT
+ && STORE_FLAG_VALUE == 1
+ && INTVAL (trueop1) < (HOST_WIDE_INT)width)
+ {
+ enum machine_mode imode = GET_MODE (XEXP (op0, 0));
+ unsigned HOST_WIDE_INT zero_val = 0;
+
+ if (CLZ_DEFINED_VALUE_AT_ZERO (imode, zero_val)
+ && zero_val == GET_MODE_BITSIZE (imode)
+ && INTVAL (trueop1) == exact_log2 (zero_val))
+ return simplify_gen_relational (EQ, mode, imode,
+ XEXP (op0, 0), const0_rtx);
+ }
break;
case SMIN:
case US_PLUS:
case SS_MINUS:
case US_MINUS:
+ case SS_ASHIFT:
/* ??? There are simplifications that can be done. */
return 0;
{
rtx op;
short neg;
- short ix;
};
-static int
-simplify_plus_minus_op_data_cmp (const void *p1, const void *p2)
+static bool
+simplify_plus_minus_op_data_cmp (rtx x, rtx y)
{
- const struct simplify_plus_minus_op_data *d1 = p1;
- const struct simplify_plus_minus_op_data *d2 = p2;
int result;
- result = (commutative_operand_precedence (d2->op)
- - commutative_operand_precedence (d1->op));
+ result = (commutative_operand_precedence (y)
+ - commutative_operand_precedence (x));
if (result)
- return result;
- return d1->ix - d2->ix;
+ return result > 0;
+
+ /* Group together equal REGs to do more simplification. */
+ if (REG_P (x) && REG_P (y))
+ return REGNO (x) > REGNO (y);
+ else
+ return false;
}
static rtx
struct simplify_plus_minus_op_data ops[8];
rtx result, tem;
int n_ops = 2, input_ops = 2;
- int first, changed, canonicalized = 0;
+ int changed, n_constants = 0, canonicalized = 0;
int i, j;
memset (ops, 0, sizeof ops);
break;
case CONST_INT:
+ n_constants++;
if (this_neg)
{
ops[i].op = neg_const_int (mode, this_op);
}
while (changed);
- gcc_assert (n_ops >= 2);
- if (!canonicalized)
- {
- int n_constants = 0;
-
- for (i = 0; i < n_ops; i++)
- if (GET_CODE (ops[i].op) == CONST_INT)
- n_constants++;
+ if (n_constants > 1)
+ canonicalized = 1;
- if (n_constants <= 1)
- return NULL_RTX;
- }
+ gcc_assert (n_ops >= 2);
/* If we only have two operands, we can avoid the loops. */
if (n_ops == 2)
return simplify_const_binary_operation (code, mode, lhs, rhs);
}
- /* Now simplify each pair of operands until nothing changes. The first
- time through just simplify constants against each other. */
-
- first = 1;
+ /* Now simplify each pair of operands until nothing changes. */
do
{
- changed = first;
+ /* Insertion sort is good enough for an eight-element array. */
+ for (i = 1; i < n_ops; i++)
+ {
+ struct simplify_plus_minus_op_data save;
+ j = i - 1;
+ if (!simplify_plus_minus_op_data_cmp (ops[j].op, ops[i].op))
+ continue;
+
+ canonicalized = 1;
+ save = ops[i];
+ do
+ ops[j + 1] = ops[j];
+ while (j-- && simplify_plus_minus_op_data_cmp (ops[j].op, save.op));
+ ops[j + 1] = save;
+ }
- for (i = 0; i < n_ops - 1; i++)
- for (j = i + 1; j < n_ops; j++)
+ /* This is only useful the first time through. */
+ if (!canonicalized)
+ return NULL_RTX;
+
+ changed = 0;
+ for (i = n_ops - 1; i > 0; i--)
+ for (j = i - 1; j >= 0; j--)
{
- rtx lhs = ops[i].op, rhs = ops[j].op;
- int lneg = ops[i].neg, rneg = ops[j].neg;
+ rtx lhs = ops[j].op, rhs = ops[i].op;
+ int lneg = ops[j].neg, rneg = ops[i].neg;
- if (lhs != 0 && rhs != 0
- && (! first || (CONSTANT_P (lhs) && CONSTANT_P (rhs))))
+ if (lhs != 0 && rhs != 0)
{
enum rtx_code ncode = PLUS;
else if (swap_commutative_operands_p (lhs, rhs))
tem = lhs, lhs = rhs, rhs = tem;
- tem = simplify_binary_operation (ncode, mode, lhs, rhs);
+ if ((GET_CODE (lhs) == CONST || GET_CODE (lhs) == CONST_INT)
+ && (GET_CODE (rhs) == CONST || GET_CODE (rhs) == CONST_INT))
+ {
+ rtx tem_lhs, tem_rhs;
+
+ tem_lhs = GET_CODE (lhs) == CONST ? XEXP (lhs, 0) : lhs;
+ tem_rhs = GET_CODE (rhs) == CONST ? XEXP (rhs, 0) : rhs;
+ tem = simplify_binary_operation (ncode, mode, tem_lhs, tem_rhs);
+ if (tem && !CONSTANT_P (tem))
+ tem = gen_rtx_CONST (GET_MODE (tem), tem);
+ }
+ else
+ tem = simplify_binary_operation (ncode, mode, lhs, rhs);
+
/* Reject "simplifications" that just wrap the two
arguments in a CONST. Failure to do so can result
in infinite recursion with simplify_binary_operation
&& ! (GET_CODE (tem) == CONST
&& GET_CODE (XEXP (tem, 0)) == ncode
&& XEXP (XEXP (tem, 0), 0) == lhs
- && XEXP (XEXP (tem, 0), 1) == rhs)
- /* Don't allow -x + -1 -> ~x simplifications in the
- first pass. This allows us the chance to combine
- the -1 with other constants. */
- && ! (first
- && GET_CODE (tem) == NOT
- && XEXP (tem, 0) == rhs))
+ && XEXP (XEXP (tem, 0), 1) == rhs))
{
lneg &= rneg;
if (GET_CODE (tem) == NEG)
}
}
- first = 0;
+ /* Pack all the operands to the lower-numbered entries. */
+ for (i = 0, j = 0; j < n_ops; j++)
+ if (ops[j].op)
+ {
+ ops[i] = ops[j];
+ i++;
+ }
+ n_ops = i;
}
while (changed);
- /* Pack all the operands to the lower-numbered entries. */
- for (i = 0, j = 0; j < n_ops; j++)
- if (ops[j].op)
- {
- ops[i] = ops[j];
- /* Stabilize sort. */
- ops[i].ix = i;
- i++;
- }
- n_ops = i;
-
- /* Sort the operations based on swap_commutative_operands_p. */
- qsort (ops, n_ops, sizeof (*ops), simplify_plus_minus_op_data_cmp);
-
/* Create (minus -C X) instead of (neg (const (plus X C))). */
if (n_ops == 2
&& GET_CODE (ops[1].op) == CONST_INT
/* Check whether an operand is suitable for calling simplify_plus_minus. */
static bool
-plus_minus_operand_p (rtx x)
+plus_minus_operand_p (const_rtx x)
{
return GET_CODE (x) == PLUS
|| GET_CODE (x) == MINUS
return simplify_relational_operation (code, mode, VOIDmode,
XEXP (op0, 0), XEXP (op0, 1));
- if (mode == VOIDmode
- || GET_MODE_CLASS (cmp_mode) == MODE_CC
+ if (GET_MODE_CLASS (cmp_mode) == MODE_CC
|| CC0_P (op0))
return NULL_RTX;
{
enum rtx_code op0code = GET_CODE (op0);
- if (GET_CODE (op1) == CONST_INT)
+ if (op1 == const0_rtx && COMPARISON_P (op0))
{
- if (INTVAL (op1) == 0 && COMPARISON_P (op0))
+ /* If op0 is a comparison, extract the comparison arguments
+ from it. */
+ if (code == NE)
{
- /* If op0 is a comparison, extract the comparison arguments form it. */
- if (code == NE)
- {
- if (GET_MODE (op0) == mode)
- return simplify_rtx (op0);
- else
- return simplify_gen_relational (GET_CODE (op0), mode, VOIDmode,
- XEXP (op0, 0), XEXP (op0, 1));
- }
- else if (code == EQ)
- {
- enum rtx_code new_code = reversed_comparison_code (op0, NULL_RTX);
- if (new_code != UNKNOWN)
- return simplify_gen_relational (new_code, mode, VOIDmode,
- XEXP (op0, 0), XEXP (op0, 1));
- }
+ if (GET_MODE (op0) == mode)
+ return simplify_rtx (op0);
+ else
+ return simplify_gen_relational (GET_CODE (op0), mode, VOIDmode,
+ XEXP (op0, 0), XEXP (op0, 1));
+ }
+ else if (code == EQ)
+ {
+ enum rtx_code new_code = reversed_comparison_code (op0, NULL_RTX);
+ if (new_code != UNKNOWN)
+ return simplify_gen_relational (new_code, mode, VOIDmode,
+ XEXP (op0, 0), XEXP (op0, 1));
}
}
+ if (op1 == const0_rtx)
+ {
+ /* Canonicalize (GTU x 0) as (NE x 0). */
+ if (code == GTU)
+ return simplify_gen_relational (NE, mode, cmp_mode, op0, op1);
+ /* Canonicalize (LEU x 0) as (EQ x 0). */
+ if (code == LEU)
+ return simplify_gen_relational (EQ, mode, cmp_mode, op0, op1);
+ }
+ else if (op1 == const1_rtx)
+ {
+ switch (code)
+ {
+ case GE:
+ /* Canonicalize (GE x 1) as (GT x 0). */
+ return simplify_gen_relational (GT, mode, cmp_mode,
+ op0, const0_rtx);
+ case GEU:
+ /* Canonicalize (GEU x 1) as (NE x 0). */
+ return simplify_gen_relational (NE, mode, cmp_mode,
+ op0, const0_rtx);
+ case LT:
+ /* Canonicalize (LT x 1) as (LE x 0). */
+ return simplify_gen_relational (LE, mode, cmp_mode,
+ op0, const0_rtx);
+ case LTU:
+ /* Canonicalize (LTU x 1) as (EQ x 0). */
+ return simplify_gen_relational (EQ, mode, cmp_mode,
+ op0, const0_rtx);
+ default:
+ break;
+ }
+ }
+ else if (op1 == constm1_rtx)
+ {
+ /* Canonicalize (LE x -1) as (LT x 0). */
+ if (code == LE)
+ return simplify_gen_relational (LT, mode, cmp_mode, op0, const0_rtx);
+ /* Canonicalize (GT x -1) as (GE x 0). */
+ if (code == GT)
+ return simplify_gen_relational (GE, mode, cmp_mode, op0, const0_rtx);
+ }
+
/* (eq/ne (plus x cst1) cst2) simplifies to (eq/ne x (cst2 - cst1)) */
if ((code == EQ || code == NE)
&& (op0code == PLUS || op0code == MINUS)
? simplify_gen_unary (ZERO_EXTEND, mode, op0, cmp_mode)
: lowpart_subreg (mode, op0, cmp_mode);
+ /* (eq/ne (xor x y) 0) simplifies to (eq/ne x y). */
+ if ((code == EQ || code == NE)
+ && op1 == const0_rtx
+ && op0code == XOR)
+ return simplify_gen_relational (code, mode, cmp_mode,
+ XEXP (op0, 0), XEXP (op0, 1));
+
+ /* (eq/ne (xor x y) x) simplifies to (eq/ne y 0). */
+ if ((code == EQ || code == NE)
+ && op0code == XOR
+ && rtx_equal_p (XEXP (op0, 0), op1)
+ && !side_effects_p (XEXP (op0, 0)))
+ return simplify_gen_relational (code, mode, cmp_mode,
+ XEXP (op0, 1), const0_rtx);
+
+ /* Likewise (eq/ne (xor x y) y) simplifies to (eq/ne x 0). */
+ if ((code == EQ || code == NE)
+ && op0code == XOR
+ && rtx_equal_p (XEXP (op0, 1), op1)
+ && !side_effects_p (XEXP (op0, 1)))
+ return simplify_gen_relational (code, mode, cmp_mode,
+ XEXP (op0, 0), const0_rtx);
+
+ /* (eq/ne (xor x C1) C2) simplifies to (eq/ne x (C1^C2)). */
+ if ((code == EQ || code == NE)
+ && op0code == XOR
+ && (GET_CODE (op1) == CONST_INT
+ || GET_CODE (op1) == CONST_DOUBLE)
+ && (GET_CODE (XEXP (op0, 1)) == CONST_INT
+ || GET_CODE (XEXP (op0, 1)) == CONST_DOUBLE))
+ return simplify_gen_relational (code, mode, cmp_mode, XEXP (op0, 0),
+ simplify_gen_binary (XOR, cmp_mode,
+ XEXP (op0, 1), op1));
+
+ if (op0code == POPCOUNT && op1 == const0_rtx)
+ switch (code)
+ {
+ case EQ:
+ case LE:
+ case LEU:
+ /* (eq (popcount x) (const_int 0)) -> (eq x (const_int 0)). */
+ return simplify_gen_relational (EQ, mode, GET_MODE (XEXP (op0, 0)),
+ XEXP (op0, 0), const0_rtx);
+
+ case NE:
+ case GT:
+ case GTU:
+ /* (ne (popcount x) (const_int 0)) -> (ne x (const_int 0)). */
+ return simplify_gen_relational (NE, mode, GET_MODE (XEXP (op0, 0)),
+ XEXP (op0, 0), const0_rtx);
+
+ default:
+ break;
+ }
+
return NULL_RTX;
}
a register or a CONST_INT, this can't help; testing for these cases will
prevent infinite recursion here and speed things up.
- If CODE is an unsigned comparison, then we can never do this optimization,
- because it gives an incorrect result if the subtraction wraps around zero.
- ANSI C defines unsigned operations such that they never overflow, and
- thus such cases can not be ignored; but we cannot do it even for
- signed comparisons for languages such as Java, so test flag_wrapv. */
+ We can only do this for EQ and NE comparisons as otherwise we may
+ lose or introduce overflow which we cannot disregard as undefined as
+ we do not know the signedness of the operation on either the left or
+ the right hand side of the comparison. */
- if (!flag_wrapv && INTEGRAL_MODE_P (mode) && trueop1 != const0_rtx
+ if (INTEGRAL_MODE_P (mode) && trueop1 != const0_rtx
+ && (code == EQ || code == NE)
&& ! ((REG_P (op0) || GET_CODE (trueop0) == CONST_INT)
&& (REG_P (op1) || GET_CODE (trueop1) == CONST_INT))
&& 0 != (tem = simplify_binary_operation (MINUS, mode, op0, op1))
- /* We cannot do this for == or != if tem is a nonzero address. */
- && ((code != EQ && code != NE) || ! nonzero_address_p (tem))
- && code != GTU && code != GEU && code != LTU && code != LEU)
+ /* We cannot do this if tem is a nonzero address. */
+ && ! nonzero_address_p (tem))
return simplify_const_relational_operation (signed_condition (code),
mode, tem, const0_rtx);
- if (flag_unsafe_math_optimizations && code == ORDERED)
+ if (! HONOR_NANS (mode) && code == ORDERED)
return const_true_rtx;
- if (flag_unsafe_math_optimizations && code == UNORDERED)
+ if (! HONOR_NANS (mode) && code == UNORDERED)
return const0_rtx;
/* For modes without NaNs, if the two operands are equal, we know the
/* Optimize abs(x) < 0.0. */
if (trueop1 == CONST0_RTX (mode)
&& !HONOR_SNANS (mode)
- && !(flag_wrapv && INTEGRAL_MODE_P (mode)))
+ && (!INTEGRAL_MODE_P (mode)
+ || (!flag_wrapv && !flag_trapv && flag_strict_overflow)))
{
tem = GET_CODE (trueop0) == FLOAT_EXTEND ? XEXP (trueop0, 0)
: trueop0;
if (GET_CODE (tem) == ABS)
- return const0_rtx;
+ {
+ if (INTEGRAL_MODE_P (mode)
+ && (issue_strict_overflow_warning
+ (WARN_STRICT_OVERFLOW_CONDITIONAL)))
+ warning (OPT_Wstrict_overflow,
+ ("assuming signed overflow does not occur when "
+ "assuming abs (x) < 0 is false"));
+ return const0_rtx;
+ }
}
+
+ /* Optimize popcount (x) < 0. */
+ if (GET_CODE (trueop0) == POPCOUNT && trueop1 == const0_rtx)
+ return const_true_rtx;
break;
case GE:
/* Optimize abs(x) >= 0.0. */
if (trueop1 == CONST0_RTX (mode)
&& !HONOR_NANS (mode)
- && !(flag_wrapv && INTEGRAL_MODE_P (mode)))
+ && (!INTEGRAL_MODE_P (mode)
+ || (!flag_wrapv && !flag_trapv && flag_strict_overflow)))
{
tem = GET_CODE (trueop0) == FLOAT_EXTEND ? XEXP (trueop0, 0)
: trueop0;
if (GET_CODE (tem) == ABS)
- return const_true_rtx;
+ {
+ if (INTEGRAL_MODE_P (mode)
+ && (issue_strict_overflow_warning
+ (WARN_STRICT_OVERFLOW_CONDITIONAL)))
+ warning (OPT_Wstrict_overflow,
+ ("assuming signed overflow does not occur when "
+ "assuming abs (x) >= 0 is true"));
+ return const_true_rtx;
+ }
}
+
+ /* Optimize popcount (x) >= 0. */
+ if (GET_CODE (trueop0) == POPCOUNT && trueop1 == const0_rtx)
+ return const_true_rtx;
break;
case UNGE:
break;
case MODE_FLOAT:
+ case MODE_DECIMAL_FLOAT:
{
REAL_VALUE_TYPE r;
long tmp[max_bitsize / 32];
return NULL_RTX;
}
+ /* Merge implicit and explicit truncations. */
+
+ if (GET_CODE (op) == TRUNCATE
+ && GET_MODE_SIZE (outermode) < GET_MODE_SIZE (innermode)
+ && subreg_lowpart_offset (outermode, innermode) == byte)
+ return simplify_gen_unary (TRUNCATE, outermode, XEXP (op, 0),
+ GET_MODE (XEXP (op, 0)));
+
/* SUBREG of a hard register => just change the register number
and/or mode. If the hard register is not valid in that mode,
suppress this simplification. If the hard register is the stack,
if (HARD_REGNO_MODE_OK (final_regno, outermode)
|| ! HARD_REGNO_MODE_OK (regno, innermode))
{
- rtx x = gen_rtx_REG_offset (op, outermode, final_regno, byte);
+ rtx x;
+ int final_offset = byte;
+
+ /* Adjust offset for paradoxical subregs. */
+ if (byte == 0
+ && GET_MODE_SIZE (innermode) < GET_MODE_SIZE (outermode))
+ {
+ int difference = (GET_MODE_SIZE (innermode)
+ - GET_MODE_SIZE (outermode));
+ if (WORDS_BIG_ENDIAN)
+ final_offset += (difference / UNITS_PER_WORD) * UNITS_PER_WORD;
+ if (BYTES_BIG_ENDIAN)
+ final_offset += difference % UNITS_PER_WORD;
+ }
+
+ x = gen_rtx_REG_offset (op, outermode, final_regno, final_offset);
/* Propagate original regno. We don't have any way to specify
the offset inside original regno, so do so only for lowpart.
of real and imaginary part. */
if (GET_CODE (op) == CONCAT)
{
- unsigned int inner_size, final_offset;
+ unsigned int part_size, final_offset;
rtx part, res;
- inner_size = GET_MODE_UNIT_SIZE (innermode);
- part = byte < inner_size ? XEXP (op, 0) : XEXP (op, 1);
- final_offset = byte % inner_size;
- if (final_offset + GET_MODE_SIZE (outermode) > inner_size)
+ part_size = GET_MODE_UNIT_SIZE (GET_MODE (XEXP (op, 0)));
+ if (byte < part_size)
+ {
+ part = XEXP (op, 0);
+ final_offset = byte;
+ }
+ else
+ {
+ part = XEXP (op, 1);
+ final_offset = byte - part_size;
+ }
+
+ if (final_offset + GET_MODE_SIZE (outermode) > part_size)
return NULL_RTX;
res = simplify_subreg (outermode, part, GET_MODE (part), final_offset);
case RTX_EXTRA:
if (code == SUBREG)
- return simplify_gen_subreg (mode, SUBREG_REG (x),
- GET_MODE (SUBREG_REG (x)),
- SUBREG_BYTE (x));
+ return simplify_subreg (mode, SUBREG_REG (x),
+ GET_MODE (SUBREG_REG (x)),
+ SUBREG_BYTE (x));
break;
case RTX_OBJ:
}
return NULL;
}
-
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