This moves one pattern from fold-const.c into match.pd.
Since no test was testing that pattern, I added a new test.
As a follow up I'll move the "(A & ~B) - (A & B) into (A ^ B) - B"
pattern.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2015-07-17 Marek Polacek <pola...@redhat.com>
* fold-const.c (fold_binary_loc): Move A - (A & B) into ~B & A ...
* match.pd: ... here.
* gcc.dg/fold-minus-7.c: New test.
diff --git gcc/fold-const.c gcc/fold-const.c
index 93dd29d..fa321f4 100644
--- gcc/fold-const.c
+++ gcc/fold-const.c
@@ -9777,30 +9777,6 @@ fold_binary_loc (location_t loc,
if (! FLOAT_TYPE_P (type))
{
- /* Fold A - (A & B) into ~B & A. */
- if (!TREE_SIDE_EFFECTS (arg0)
- && TREE_CODE (arg1) == BIT_AND_EXPR)
- {
- if (operand_equal_p (arg0, TREE_OPERAND (arg1, 1), 0))
- {
- tree arg10 = 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, arg10),
- fold_convert_loc (loc, type, arg0));
- }
- if (operand_equal_p (arg0, TREE_OPERAND (arg1, 0), 0))
- {
- tree arg11 = fold_convert_loc (loc,
- type, TREE_OPERAND (arg1, 1));
- return fold_build2_loc (loc, BIT_AND_EXPR, type,
- fold_build1_loc (loc, BIT_NOT_EXPR,
- type, arg11),
- fold_convert_loc (loc, type, arg0));
- }
- }
-
/* 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
diff --git gcc/match.pd gcc/match.pd
index c335ada..066d5de 100644
--- gcc/match.pd
+++ gcc/match.pd
@@ -662,6 +662,10 @@ along with GCC; see the file COPYING3. If not see
(bit_ior:c (bit_and:cs @0 (bit_not @2)) (bit_and:cs @1 @2))
(bit_xor (bit_and (bit_xor @0 @1) @2) @0))
+/* Fold A - (A & B) into ~B & A. */
+(simplify
+ (minus (convert? @0) (convert? (bit_and:c @0 @1)))
+ (convert (bit_and (bit_not @1) @0)))
/* Associate (p +p off1) +p off2 as (p +p (off1 + off2)). */
(simplify
diff --git gcc/testsuite/gcc.dg/fold-minus-7.c
gcc/testsuite/gcc.dg/fold-minus-7.c
index e69de29..7a49faa 100644
--- gcc/testsuite/gcc.dg/fold-minus-7.c
+++ gcc/testsuite/gcc.dg/fold-minus-7.c
@@ -0,0 +1,36 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+f1 (int a, int b)
+{
+ int tem = a & b;
+ return a - tem;
+}
+
+int
+f2 (int a, int b)
+{
+ int tem = b & a;
+ return a - tem;
+}
+
+int
+f3 (unsigned int a, int b)
+{
+ return a - (a & b);
+}
+
+int
+f4 (int a, unsigned int b)
+{
+ return a - (a & b);
+}
+
+int
+f5 (int a, int b)
+{
+ return a - (unsigned) (b & a);
+}
+
+/* { dg-final { scan-tree-dump-not " - " "cddce1" } } */
Marek
