/* 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 Free Software Foundation, Inc.
This file is part of GCC.
{
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
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
+ || ((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
+ && ((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:
+ 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)));
+ 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:
case FLOAT_TRUNCATE:
case SS_TRUNCATE:
case US_TRUNCATE:
+ case SS_NEG:
return 0;
default:
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 (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 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 (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 (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).
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)
&& ! 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;
+
+ /* 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;
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;
return simplify_gen_unary (ZERO_EXTEND, mode, tem, imode);
}
+ /* 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 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:
{
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
- commutative_operand_precedence (d1->op));
if (result)
return result;
- return d1->ix - d2->ix;
+
+ /* Group together equal REGs to do more simplification. */
+ if (REG_P (d1->op) && REG_P (d2->op))
+ return REGNO (d1->op) - REGNO (d2->op);
+ else
+ return 0;
}
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], &ops[i]) < 0)
+ continue;
+
+ canonicalized = 1;
+ save = ops[i];
+ do
+ ops[j + 1] = ops[j];
+ while (j-- && simplify_plus_minus_op_data_cmp (&ops[j], &save) > 0);
+ 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];
- /* 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
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;
{
if (INTVAL (op1) == 0 && COMPARISON_P (op0))
{
- /* If op0 is a comparison, extract the comparison arguments form it. */
+ /* If op0 is a comparison, extract the comparison arguments
+ from it. */
if (code == NE)
{
if (GET_MODE (op0) == mode)
? 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));
+
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);
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.
}
return NULL;
}
+
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