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Move some bit and binary optimizations in simplify and match
- From: "Hurugalawadi, Naveen" <Naveen dot Hurugalawadi at caviumnetworks dot com>
- To: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Date: Wed, 7 Oct 2015 09:54:11 +0000
- Subject: Move some bit and binary optimizations in simplify and match
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- Authentication-results: spf=none (sender IP is ) smtp dot mailfrom=Naveen dot Hurugalawadi at caviumnetworks dot com;
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Hi,
Please find attached the patch that moves some more patterns from
fold-const using simplify and match.
Please review the patch and let me know if any modifications are required.
Tested the patch on X86 without any regressions.
Thanks,
Naveen
ChangeLog
2015-10-07 Naveen H.S <Naveen.Hurugalawadi@caviumnetworks.com>
* fold-const.c (fold_binary_loc) : Move X + (X / CST) * -CST ->
X % CST to match.pd.
Move Fold (A & ~B) - (A & B) into (A ^ B) - B to match.pd.
Move (-A) * (-B) -> A * B to match.pd.
Move (a * (1 << b)) is (a << b) to match.pd.
Move convert (C1/X)*C2 into (C1*C2)/X to match.pd.
Move (X & ~Y) | (~X & Y) is X ^ Y to match.pd.
Move ~X & X, (X == 0) & X, and !X & X are zero to match.pd.
Move X & ~X , X & (X == 0), and X & !X are zero to match.pd.
Move Fold X & (X ^ Y) as X & ~Y to match.pd.
Move Fold X & (Y ^ X) as ~Y & X to match.pd.
* match.pd (plus @0 (mult:s (trunc_div:s @0 INTEGER_CST@1)
(negate @1))): New simplifier.
(minus (bit_and:s @0 (bit_not:s @1)) (bit_and:s @0 @1)) :
New simplifier.
(mult:c @0 (lshift integer_onep@1 @2)): New simplifier.
(mult:c (plus @0 @0) INTEGER_CST@1): New simplifier.
(mult (rdiv REAL_CST@0 @1) REAL_CST@2): New simplifier.
(bit_ior (bit_and:s @0 (bit_not:s @1)) (bit_and:s (bit_not:s @0) @1))
: New simplifier.
(bit_and:c @0 (bit_not:s @0)): New simplifier.
(bit_and:c @0 (eq @0 integer_zerop@1)): New simplifier.
(bit_and @0 (bit_xor:s @0 @1)): New simplifier.
(bit_and @0 (bit_xor:s @1 @0)): New simplifier.
(mult:c (negate @0) (negate @1)): New simplifier.
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 7231fd6..ad850f0 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -9191,26 +9191,6 @@ fold_binary_loc (location_t loc,
return NULL_TREE;
case PLUS_EXPR:
- if (INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type))
- {
- /* X + (X / CST) * -CST is X % CST. */
- if (TREE_CODE (arg1) == MULT_EXPR
- && TREE_CODE (TREE_OPERAND (arg1, 0)) == TRUNC_DIV_EXPR
- && operand_equal_p (arg0,
- TREE_OPERAND (TREE_OPERAND (arg1, 0), 0), 0))
- {
- tree cst0 = TREE_OPERAND (TREE_OPERAND (arg1, 0), 1);
- tree cst1 = TREE_OPERAND (arg1, 1);
- tree sum = fold_binary_loc (loc, PLUS_EXPR, TREE_TYPE (cst1),
- cst1, cst0);
- if (sum && integer_zerop (sum))
- return fold_convert_loc (loc, type,
- fold_build2_loc (loc, TRUNC_MOD_EXPR,
- TREE_TYPE (arg0), arg0,
- cst0));
- }
- }
-
/* Handle (A1 * C1) + (A2 * C2) with A1, A2 or C1, C2 being the same or
one. Make sure the type is not saturating and has the signedness of
the stripped operands, as fold_plusminus_mult_expr will re-associate.
@@ -9651,28 +9631,6 @@ fold_binary_loc (location_t loc,
fold_convert_loc (loc, type,
TREE_OPERAND (arg0, 0)));
- if (! FLOAT_TYPE_P (type))
- {
- /* Fold (A & ~B) - (A & B) into (A ^ B) - B, where B is
- any power of 2 minus 1. */
- if (TREE_CODE (arg0) == BIT_AND_EXPR
- && TREE_CODE (arg1) == BIT_AND_EXPR
- && operand_equal_p (TREE_OPERAND (arg0, 0),
- TREE_OPERAND (arg1, 0), 0))
- {
- tree mask0 = TREE_OPERAND (arg0, 1);
- tree mask1 = TREE_OPERAND (arg1, 1);
- tree tem = fold_build1_loc (loc, BIT_NOT_EXPR, type, mask0);
-
- if (operand_equal_p (tem, mask1, 0))
- {
- tem = fold_build2_loc (loc, BIT_XOR_EXPR, type,
- TREE_OPERAND (arg0, 0), mask1);
- return fold_build2_loc (loc, MINUS_EXPR, type, tem, mask1);
- }
- }
- }
-
/* Fold __complex__ ( x, 0 ) - __complex__ ( 0, y ) to
__complex__ ( x, -y ). This is not the same for SNaNs or if
signed zeros are involved. */
@@ -9762,20 +9720,6 @@ fold_binary_loc (location_t loc,
goto associate;
case MULT_EXPR:
- /* (-A) * (-B) -> A * B */
- if (TREE_CODE (arg0) == NEGATE_EXPR && negate_expr_p (arg1))
- return fold_build2_loc (loc, MULT_EXPR, type,
- fold_convert_loc (loc, type,
- TREE_OPERAND (arg0, 0)),
- fold_convert_loc (loc, type,
- negate_expr (arg1)));
- if (TREE_CODE (arg1) == NEGATE_EXPR && negate_expr_p (arg0))
- return fold_build2_loc (loc, MULT_EXPR, type,
- fold_convert_loc (loc, type,
- negate_expr (arg0)),
- fold_convert_loc (loc, type,
- TREE_OPERAND (arg1, 0)));
-
if (! FLOAT_TYPE_P (type))
{
/* Transform x * -C into -x * C if x is easily negatable. */
@@ -9789,16 +9733,6 @@ fold_binary_loc (location_t loc,
negate_expr (arg0)),
tem);
- /* (a * (1 << b)) is (a << b) */
- if (TREE_CODE (arg1) == LSHIFT_EXPR
- && integer_onep (TREE_OPERAND (arg1, 0)))
- return fold_build2_loc (loc, LSHIFT_EXPR, type, op0,
- TREE_OPERAND (arg1, 1));
- if (TREE_CODE (arg0) == LSHIFT_EXPR
- && integer_onep (TREE_OPERAND (arg0, 0)))
- return fold_build2_loc (loc, LSHIFT_EXPR, type, op1,
- TREE_OPERAND (arg0, 1));
-
/* (A + A) * C -> A * 2 * C */
if (TREE_CODE (arg0) == PLUS_EXPR
&& TREE_CODE (arg1) == INTEGER_CST
@@ -9841,21 +9775,6 @@ fold_binary_loc (location_t loc,
}
else
{
- /* Convert (C1/X)*C2 into (C1*C2)/X. This transformation may change
- the result for floating point types due to rounding so it is applied
- only if -fassociative-math was specify. */
- if (flag_associative_math
- && TREE_CODE (arg0) == RDIV_EXPR
- && TREE_CODE (arg1) == REAL_CST
- && TREE_CODE (TREE_OPERAND (arg0, 0)) == REAL_CST)
- {
- tree tem = const_binop (MULT_EXPR, TREE_OPERAND (arg0, 0),
- arg1);
- if (tem)
- return fold_build2_loc (loc, RDIV_EXPR, type, tem,
- TREE_OPERAND (arg0, 1));
- }
-
/* Strip sign operations from X in X*X, i.e. -Y*-Y -> Y*Y. */
if (operand_equal_p (arg0, arg1, 0))
{
@@ -9972,28 +9891,6 @@ fold_binary_loc (location_t loc,
arg1);
}
- /* (X & ~Y) | (~X & Y) is X ^ Y */
- if (TREE_CODE (arg0) == BIT_AND_EXPR
- && TREE_CODE (arg1) == BIT_AND_EXPR)
- {
- tree a0, a1, l0, l1, n0, n1;
-
- a0 = fold_convert_loc (loc, type, TREE_OPERAND (arg1, 0));
- a1 = fold_convert_loc (loc, type, TREE_OPERAND (arg1, 1));
-
- l0 = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0));
- l1 = fold_convert_loc (loc, type, TREE_OPERAND (arg0, 1));
-
- n0 = fold_build1_loc (loc, BIT_NOT_EXPR, type, l0);
- n1 = fold_build1_loc (loc, BIT_NOT_EXPR, type, l1);
-
- if ((operand_equal_p (n0, a0, 0)
- && operand_equal_p (n1, a1, 0))
- || (operand_equal_p (n0, a1, 0)
- && operand_equal_p (n1, a0, 0)))
- return fold_build2_loc (loc, BIT_XOR_EXPR, type, l0, n1);
- }
-
/* See if this can be simplified into a rotate first. If that
is unsuccessful continue in the association code. */
goto bit_rotate;
@@ -10012,22 +9909,6 @@ fold_binary_loc (location_t loc,
goto bit_rotate;
case BIT_AND_EXPR:
- /* ~X & X, (X == 0) & X, and !X & X are always zero. */
- if ((TREE_CODE (arg0) == BIT_NOT_EXPR
- || TREE_CODE (arg0) == TRUTH_NOT_EXPR
- || (TREE_CODE (arg0) == EQ_EXPR
- && integer_zerop (TREE_OPERAND (arg0, 1))))
- && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
- return omit_one_operand_loc (loc, type, integer_zero_node, arg1);
-
- /* X & ~X , X & (X == 0), and X & !X are always zero. */
- if ((TREE_CODE (arg1) == BIT_NOT_EXPR
- || TREE_CODE (arg1) == TRUTH_NOT_EXPR
- || (TREE_CODE (arg1) == EQ_EXPR
- && integer_zerop (TREE_OPERAND (arg1, 1))))
- && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
- return omit_one_operand_loc (loc, type, integer_zero_node, arg0);
-
/* Fold (X ^ 1) & 1 as (X & 1) == 0. */
if (TREE_CODE (arg0) == BIT_XOR_EXPR
&& INTEGRAL_TYPE_P (type)
@@ -10083,26 +9964,6 @@ fold_binary_loc (location_t loc,
fold_build1_loc (loc, BIT_NOT_EXPR, type, tem),
fold_convert_loc (loc, type, arg1));
}
- /* Fold X & (X ^ Y) as X & ~Y. */
- if (TREE_CODE (arg1) == BIT_XOR_EXPR
- && operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
- {
- tem = fold_convert_loc (loc, type, TREE_OPERAND (arg1, 1));
- return fold_build2_loc (loc, BIT_AND_EXPR, type,
- fold_convert_loc (loc, type, arg0),
- fold_build1_loc (loc, BIT_NOT_EXPR, type, tem));
- }
- /* Fold X & (Y ^ X) as ~Y & X. */
- if (TREE_CODE (arg1) == BIT_XOR_EXPR
- && operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0)
- && reorder_operands_p (arg0, TREE_OPERAND (arg1, 0)))
- {
- tem = fold_convert_loc (loc, type, TREE_OPERAND (arg1, 0));
- return fold_build2_loc (loc, BIT_AND_EXPR, type,
- fold_build1_loc (loc, BIT_NOT_EXPR, type, tem),
- fold_convert_loc (loc, type, arg0));
- }
-
/* Fold (X * Y) & -(1 << CST) to X * Y if Y is a constant
multiple of 1 << CST. */
if (TREE_CODE (arg1) == INTEGER_CST)
diff --git a/gcc/match.pd b/gcc/match.pd
index bd5c267..690ea14 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -316,6 +316,56 @@ along with GCC; see the file COPYING3. If not see
(coss (op @0))
(coss @0))))
+/* Fold X + (X / CST) * -CST to X % CST. */
+(simplify
+ (plus @0 (mult:s (trunc_div:s @0 INTEGER_CST@1) (negate @1)))
+ (if (INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type))
+ (trunc_mod @0 @1)))
+
+/* Fold (A & ~B) - (A & B) into (A ^ B) - B. */
+(simplify
+ (minus (bit_and:s @0 (bit_not:s @1)) (bit_and:s @0 @1))
+ (if (! FLOAT_TYPE_P (type))
+ (minus (bit_xor @0 @1) @1)))
+
+/* Fold (a * (1 << b)) into (a << b) */
+(simplify
+ (mult:c @0 (lshift integer_onep@1 @2))
+ (if (! FLOAT_TYPE_P (type))
+ (lshift @0 @2)))
+
+/* Fold (C1/X)*C2 into (C1*C2)/X. */
+(simplify
+ (mult (rdiv REAL_CST@0 @1) REAL_CST@2)
+ (if (FLOAT_TYPE_P (type)
+ && flag_associative_math)
+ (rdiv (mult @0 @2) @1)))
+
+/* Simplify (X & ~Y) | (~X & Y) is X ^ Y. */
+(simplify
+ (bit_ior (bit_and:s @0 (bit_not:s @1)) (bit_and:s (bit_not:s @0) @1))
+ (bit_xor @0 @1))
+
+/* Simplify ~X & X as zero. */
+(simplify
+ (bit_and:c @0 (bit_not:s @0))
+ { build_zero_cst (type); })
+
+/* Simplify (X == 0) & X as zero. */
+(simplify
+ (bit_and:c @0 (eq @0 integer_zerop@1))
+ @1)
+
+/* Fold X & (X ^ Y) as X & ~Y. */
+(simplify
+ (bit_and @0 (bit_xor:s @0 @1))
+ (bit_and @0 (bit_not @1)))
+
+/* Fold X & (Y ^ X) as ~Y & X. */
+(simplify
+ (bit_and @0 (bit_xor:s @1 @0))
+ (bit_and (bit_not @1) @0))
+
/* X % Y is smaller than Y. */
(for cmp (lt ge)
(simplify
@@ -549,6 +599,11 @@ along with GCC; see the file COPYING3. If not see
(if (!FIXED_POINT_TYPE_P (type))
(plus @0 (negate @1))))
+/* (-A) * (-B) -> A * B */
+(simplify
+ (mult:c (negate @0) (negate @1))
+ (mult @0 @1))
+
/* Try to fold (type) X op CST -> (type) (X op ((type-x) CST))
when profitable.
For bitwise binary operations apply operand conversions to the