/* 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 simplify_plus_minus (enum rtx_code, enum machine_mode, rtx,
- rtx, int);
+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,
/* 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;
- /* Handle addition and subtraction specially. Otherwise, just form
- the operation. */
-
- if (code == PLUS || code == MINUS)
- {
- tem = simplify_plus_minus (code, mode, op0, op1, 1);
- 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);
}
return x;
}
+ if (GET_MODE (x) == BLKmode)
+ return x;
+
addr = XEXP (x, 0);
/* Call target hook to avoid the effects of -fpic etc.... */
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);
if (GET_CODE (op) == NOT)
return XEXP (op, 0);
- /* (not (eq X Y)) == (ne X Y), etc. */
+ /* (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_binary (ROTATE, mode, temp, XEXP (op, 1));
}
- /* If STORE_FLAG_VALUE is -1, (not (comparison X Y)) can be done
- by reversing the comparison code if valid. */
- if (STORE_FLAG_VALUE == -1
- && COMPARISON_P (op)
- && (reversed = reversed_comparison_code (op, NULL_RTX)) != UNKNOWN)
- return simplify_gen_relational (reversed, mode, VOIDmode,
- XEXP (op, 0), 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
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:
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)
+ {
+ 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:
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;
}
else if (GET_CODE (op) == CONST_DOUBLE
- && GET_MODE_CLASS (mode) == MODE_FLOAT)
+ && SCALAR_FLOAT_MODE_P (mode))
{
REAL_VALUE_TYPE d, t;
REAL_VALUE_FROM_CONST_DOUBLE (d, op);
}
else if (GET_CODE (op) == CONST_DOUBLE
- && GET_MODE_CLASS (GET_MODE (op)) == MODE_FLOAT
+ && SCALAR_FLOAT_MODE_P (GET_MODE (op))
&& GET_MODE_CLASS (mode) == MODE_INT
&& width <= 2*HOST_BITS_PER_WIDE_INT && width > 0)
{
}
/* 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)
{
- rtx tem;
+ rtx tem, reversed, opleft, opright;
HOST_WIDE_INT val;
unsigned int width = GET_MODE_BITSIZE (mode);
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.
if (INTEGRAL_MODE_P (mode)
&& (plus_minus_operand_p (op0)
|| plus_minus_operand_p (op1))
- && (tem = simplify_plus_minus (code, mode, op0, op1, 0)) != 0)
+ && (tem = simplify_plus_minus (code, mode, op0, op1)) != 0)
return tem;
/* Reassociate floating point addition only when the user
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 simplify_gen_binary (MINUS, mode, tem, XEXP (op0, 0));
}
- /* 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)) != 0)
- return tem;
-
/* 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,
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:
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));
/* x*2 is x+x and x*(-1) is -x */
if (GET_CODE (trueop1) == CONST_DOUBLE
- && GET_MODE_CLASS (GET_MODE (trueop1)) == MODE_FLOAT
+ && SCALAR_FLOAT_MODE_P (GET_MODE (trueop1))
&& GET_MODE (op0) == mode)
{
REAL_VALUE_TYPE d;
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)
&& ! 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;
&& ((INTVAL (trueop1) & GET_MODE_MASK (mode))
== GET_MODE_MASK (mode)))
return simplify_gen_unary (NOT, mode, op0, mode);
- if (trueop0 == trueop1
+ if (rtx_equal_p (trueop0, trueop1)
&& ! side_effects_p (op0)
&& GET_MODE_CLASS (mode) != MODE_CC)
return CONST0_RTX (mode);
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;
+
+ break;
+
tem = simplify_associative_operation (code, mode, op0, op1);
if (tem)
return tem;
&& GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
&& (nonzero_bits (trueop0, mode) & ~INTVAL (trueop1)) == 0)
return op0;
- if (trueop0 == trueop1 && ! side_effects_p (op0)
+ if (rtx_equal_p (trueop0, trueop1) && ! side_effects_p (op0)
&& GET_MODE_CLASS (mode) != MODE_CC)
return op0;
/* A & (~A) -> 0 */
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,
case DIV:
/* Handle floating point and integers separately. */
- if (GET_MODE_CLASS (mode) == MODE_FLOAT)
+ 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
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:
return gen_rtx_CONST_VECTOR (mode, v);
}
}
+
+ if (XVECLEN (trueop1, 0) == 1
+ && GET_CODE (XVECEXP (trueop1, 0, 0)) == CONST_INT
+ && GET_CODE (trueop0) == VEC_CONCAT)
+ {
+ rtx vec = trueop0;
+ int offset = INTVAL (XVECEXP (trueop1, 0, 0)) * GET_MODE_SIZE (mode);
+
+ /* Try to find the element in the VEC_CONCAT. */
+ while (GET_MODE (vec) != mode
+ && GET_CODE (vec) == VEC_CONCAT)
+ {
+ HOST_WIDE_INT vec_size = GET_MODE_SIZE (GET_MODE (XEXP (vec, 0)));
+ if (offset < vec_size)
+ vec = XEXP (vec, 0);
+ else
+ {
+ offset -= vec_size;
+ vec = XEXP (vec, 1);
+ }
+ vec = avoid_constant_pool_reference (vec);
+ }
+
+ if (GET_MODE (vec) == mode)
+ return vec;
+ }
+
return 0;
case VEC_CONCAT:
{
return gen_rtx_CONST_VECTOR (mode, v);
}
- if (GET_MODE_CLASS (mode) == MODE_FLOAT
+ if (SCALAR_FLOAT_MODE_P (mode)
&& GET_CODE (op0) == CONST_DOUBLE
&& GET_CODE (op1) == CONST_DOUBLE
&& mode == GET_MODE (op0) && mode == GET_MODE (op1))
&f0, &f1);
real_convert (&result, mode, &value);
+ /* Don't constant fold this floating point operation if
+ the result has overflowed and flag_trapping_math. */
+
+ if (flag_trapping_math
+ && MODE_HAS_INFINITIES (mode)
+ && REAL_VALUE_ISINF (result)
+ && !REAL_VALUE_ISINF (f0)
+ && !REAL_VALUE_ISINF (f1))
+ /* Overflow plus exception. */
+ return 0;
+
/* Don't constant fold this floating point operation if the
result may dependent upon the run-time rounding mode and
flag_rounding_math is set, or if GCC's software emulation
case US_PLUS:
case SS_MINUS:
case US_MINUS:
+ case SS_ASHIFT:
/* ??? There are simplifications that can be done. */
return 0;
Rather than test for specific case, we do this by a brute-force method
and do all possible simplifications until no more changes occur. Then
- we rebuild the operation.
-
- If FORCE is true, then always generate the rtx. This is used to
- canonicalize stuff emitted from simplify_gen_binary. Note that this
- can still fail if the rtx is too complex. It won't fail just because
- the result is not 'simpler' than the input, however. */
+ we rebuild the operation. */
struct simplify_plus_minus_op_data
{
rtx op;
- int neg;
+ 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 (y)
+ - commutative_operand_precedence (x));
+ if (result)
+ return result > 0;
- return (commutative_operand_precedence (d2->op)
- - commutative_operand_precedence (d1->op));
+ /* 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
simplify_plus_minus (enum rtx_code code, enum machine_mode mode, rtx op0,
- rtx op1, int force)
+ rtx op1)
{
struct simplify_plus_minus_op_data ops[8];
rtx result, tem;
- int n_ops = 2, input_ops = 2, input_consts = 0, n_consts;
- int first, changed;
+ int n_ops = 2, input_ops = 2;
+ int changed, n_constants = 0, canonicalized = 0;
int i, j;
memset (ops, 0, sizeof ops);
ops[i].op = XEXP (this_op, 0);
input_ops++;
changed = 1;
+ canonicalized |= this_neg;
break;
case NEG:
ops[i].op = XEXP (this_op, 0);
ops[i].neg = ! this_neg;
changed = 1;
+ canonicalized = 1;
break;
case CONST:
ops[n_ops].op = XEXP (XEXP (this_op, 0), 1);
ops[n_ops].neg = this_neg;
n_ops++;
- input_consts++;
changed = 1;
+ canonicalized = 1;
}
break;
ops[i].op = XEXP (this_op, 0);
ops[i].neg = !this_neg;
changed = 1;
+ canonicalized = 1;
}
break;
case CONST_INT:
+ n_constants++;
if (this_neg)
{
ops[i].op = neg_const_int (mode, this_op);
ops[i].neg = 0;
changed = 1;
+ canonicalized = 1;
}
break;
}
while (changed);
- /* If we only have two operands, we can't do anything. */
- if (n_ops <= 2 && !force)
- return NULL_RTX;
+ if (n_constants > 1)
+ canonicalized = 1;
+
+ gcc_assert (n_ops >= 2);
- /* Count the number of CONSTs we didn't split above. */
- for (i = 0; i < n_ops; i++)
- if (GET_CODE (ops[i].op) == CONST)
- input_consts++;
+ /* If we only have two operands, we can avoid the loops. */
+ if (n_ops == 2)
+ {
+ enum rtx_code code = ops[0].neg || ops[1].neg ? MINUS : PLUS;
+ rtx lhs, rhs;
- /* Now simplify each pair of operands until nothing changes. The first
- time through just simplify constants against each other. */
+ /* Get the two operands. Be careful with the order, especially for
+ the cases where code == MINUS. */
+ if (ops[0].neg && ops[1].neg)
+ {
+ lhs = gen_rtx_NEG (mode, ops[0].op);
+ rhs = ops[1].op;
+ }
+ else if (ops[0].neg)
+ {
+ lhs = ops[1].op;
+ rhs = ops[0].op;
+ }
+ else
+ {
+ lhs = ops[0].op;
+ rhs = ops[1].op;
+ }
- first = 1;
+ return simplify_const_binary_operation (code, mode, lhs, rhs);
+ }
+
+ /* 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;
+ }
+
+ /* This is only useful the first time through. */
+ if (!canonicalized)
+ return NULL_RTX;
- for (i = 0; i < n_ops - 1; i++)
- for (j = i + 1; j < n_ops; j++)
+ 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];
- 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
n_ops--;
}
- /* Count the number of CONSTs that we generated. */
- n_consts = 0;
- for (i = 0; i < n_ops; i++)
- if (GET_CODE (ops[i].op) == CONST)
- n_consts++;
-
- /* Give up if we didn't reduce the number of operands we had. Make
- sure we count a CONST as two operands. If we have the same
- number of operands, but have made more CONSTs than before, this
- is also an improvement, so accept it. */
- if (!force
- && (n_ops + n_consts > input_ops
- || (n_ops + n_consts == input_ops && n_consts <= input_consts)))
- return NULL_RTX;
-
/* Put a non-negated operand first, if possible. */
for (i = 0; i < n_ops && ops[i].neg; i++)
/* 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
tem = simplify_const_relational_operation (code, cmp_mode, op0, op1);
if (tem)
{
- if (GET_MODE_CLASS (mode) == MODE_FLOAT)
+ if (SCALAR_FLOAT_MODE_P (mode))
{
if (tem == const0_rtx)
return CONST0_RTX (mode);
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)
? 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
the result. */
else if (GET_CODE (trueop0) == CONST_DOUBLE
&& GET_CODE (trueop1) == CONST_DOUBLE
- && GET_MODE_CLASS (GET_MODE (trueop0)) == MODE_FLOAT)
+ && SCALAR_FLOAT_MODE_P (GET_MODE (trueop0)))
{
REAL_VALUE_TYPE d0, d1;
/* 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:
}
/* It shouldn't matter what's done here, so fill it with
zero. */
- for (; i < max_bitsize; i += value_bit)
+ for (; i < elem_bitsize; i += value_bit)
*vp++ = 0;
}
else
long tmp[max_bitsize / 32];
int bitsize = GET_MODE_BITSIZE (GET_MODE (el));
- gcc_assert (GET_MODE_CLASS (GET_MODE (el)) == MODE_FLOAT);
+ gcc_assert (SCALAR_FLOAT_MODE_P (GET_MODE (el)));
gcc_assert (bitsize <= elem_bitsize);
gcc_assert (bitsize % value_bit == 0);
know why. */
if (elem_bitsize <= HOST_BITS_PER_WIDE_INT)
elems[elem] = gen_int_mode (lo, outer_submode);
- else
+ else if (elem_bitsize <= 2 * HOST_BITS_PER_WIDE_INT)
elems[elem] = immed_double_const (lo, hi, outer_submode);
+ else
+ return NULL_RTX;
}
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: