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authorglisse <glisse@138bc75d-0d04-0410-961f-82ee72b054a4>2016-05-10 19:52:20 +0000
committerglisse <glisse@138bc75d-0d04-0410-961f-82ee72b054a4>2016-05-10 19:52:20 +0000
commitf9153689e2ce4b8e19fbe2303a545d3cbedfa34e (patch)
tree0a73b6e9c04150d305bc301e3cee930e37a9d50d /gcc/match.pd
parent3604118da2f0e62a75ebd6d206a8cd3ef2573b01 (diff)
downloadgcc-f9153689e2ce4b8e19fbe2303a545d3cbedfa34e.tar.gz
Simple bitop reassoc in match.pd
2016-05-10 Marc Glisse <marc.glisse@inria.fr> gcc/ * fold-const.c (fold_binary_loc) [(X ^ Y) & Y]: Remove and merge with... * match.pd ((X & Y) ^ Y): ... this. ((X & Y) & Y, (X | Y) | Y, (X ^ Y) ^ Y, (X & Y) & (X & Z), (X | Y) | (X | Z), (X ^ Y) ^ (X ^ Z)): New transformations. gcc/testsuite/ * gcc.dg/tree-ssa/bit-assoc.c: New testcase. * gcc.dg/tree-ssa/pr69270.c: Adjust. * gcc.dg/tree-ssa/vrp59.c: Disable forwprop. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@236103 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/match.pd')
-rw-r--r--gcc/match.pd39
1 files changed, 35 insertions, 4 deletions
diff --git a/gcc/match.pd b/gcc/match.pd
index e511e9a6b9b..5b3cb3bfd5e 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -674,10 +674,12 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
(bit_xor (convert @0) (bit_not @1))))
-/* Fold (X & Y) ^ Y as ~X & Y. */
-(simplify
- (bit_xor:c (bit_and:c @0 @1) @1)
- (bit_and (bit_not @0) @1))
+/* Fold (X & Y) ^ Y and (X ^ Y) & Y as ~X & Y. */
+(for opo (bit_and bit_xor)
+ opi (bit_xor bit_and)
+ (simplify
+ (opo:c (opi:c @0 @1) @1)
+ (bit_and (bit_not @0) @1)))
/* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
operands are another bit-wise operation with a common input. If so,
@@ -693,6 +695,35 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
&& tree_nop_conversion_p (type, TREE_TYPE (@2)))
(rop (convert @0) (op (convert @1) (convert @2))))))
+/* Some simple reassociation for bit operations, also handled in reassoc. */
+/* (X & Y) & Y -> X & Y
+ (X | Y) | Y -> X | Y */
+(for op (bit_and bit_ior)
+ (simplify
+ (op:c (convert?@2 (op:c @0 @1)) (convert? @1))
+ @2))
+/* (X ^ Y) ^ Y -> X */
+(simplify
+ (bit_xor:c (convert? (bit_xor:c @0 @1)) (convert? @1))
+ (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
+ (convert @0)))
+/* (X & Y) & (X & Z) -> (X & Y) & Z
+ (X | Y) | (X | Z) -> (X | Y) | Z */
+(for op (bit_and bit_ior)
+ (simplify
+ (op:c (convert1?@3 (op:c@4 @0 @1)) (convert2?@5 (op:c@6 @0 @2)))
+ (if (tree_nop_conversion_p (type, TREE_TYPE (@1))
+ && tree_nop_conversion_p (type, TREE_TYPE (@2)))
+ (if (single_use (@5) && single_use (@6))
+ (op @3 (convert @2))
+ (if (single_use (@3) && single_use (@4))
+ (op (convert @1) @5))))))
+/* (X ^ Y) ^ (X ^ Z) -> Y ^ Z */
+(simplify
+ (bit_xor (convert1? (bit_xor:c @0 @1)) (convert2? (bit_xor:c @0 @2)))
+ (if (tree_nop_conversion_p (type, TREE_TYPE (@1))
+ && tree_nop_conversion_p (type, TREE_TYPE (@2)))
+ (convert (bit_xor @1 @2))))
(simplify
(abs (abs@1 @0))