/* 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 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;
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);
/* (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)));
*/
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;
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));
}
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;
&& (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)
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
short neg;
};
-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 result > 0;
/* Group together equal REGs to do more simplification. */
- if (REG_P (d1->op) && REG_P (d2->op))
- return REGNO (d1->op) - REGNO (d2->op);
+ if (REG_P (x) && REG_P (y))
+ return REGNO (x) > REGNO (y);
else
- return 0;
+ return false;
}
static rtx
{
struct simplify_plus_minus_op_data save;
j = i - 1;
- if (simplify_plus_minus_op_data_cmp (&ops[j], &ops[i]) < 0)
+ 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], &save) > 0);
+ while (j-- && simplify_plus_minus_op_data_cmp (ops[j].op, save.op));
ops[j + 1] = save;
}
/* 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
{
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
- from 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_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;
}
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:
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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