From: Andrew Pinski <apin...@marvell.com> The following makes sure to fold (~a) == b to a ^ b for truth values.
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions. Thanks, Andrew Pinski PR 103356 gcc/ChangeLog: * match.pd: ((~a) == b -> a ^ b): New pattern. gcc/testsuite/ChangeLog: * gcc.dg/pr103356-1.c: New test. --- gcc/match.pd | 7 +++++++ gcc/testsuite/gcc.dg/pr103356-1.c | 9 +++++++++ 2 files changed, 16 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/pr103356-1.c diff --git a/gcc/match.pd b/gcc/match.pd index a4d1386fd9f..67a0a682f31 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -1999,6 +1999,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) && TYPE_PRECISION (TREE_TYPE (@0)) == 1) (convert (eq @0 @1)))) +/* (~a) == b is a ^ b for truth valued a and b. */ +(simplify + (eq:c (bit_not:s truth_valued_p@0) truth_valued_p@1) + (if (INTEGRAL_TYPE_P (TREE_TYPE (@0)) + && TYPE_PRECISION (TREE_TYPE (@0)) == 1) + (convert (bit_xor @0 @1)))) + /* (x & ~m) | (y & m) -> ((x ^ y) & m) ^ x */ (simplify (bit_ior:c (bit_and:cs @0 (bit_not @2)) (bit_and:cs @1 @2)) diff --git a/gcc/testsuite/gcc.dg/pr103356-1.c b/gcc/testsuite/gcc.dg/pr103356-1.c new file mode 100644 index 00000000000..61d0b81da22 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr103356-1.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-O -fdump-tree-forwprop1" } */ + +_Bool foo (_Bool a, _Bool b) +{ + return a == (!b); +} + +/* { dg-final { scan-tree-dump "\[ab\]_\[0-9\]+\\(D\\) \\\^ \[ba\]_\[0-9\]+\\(D\\)" "forwprop1" } } */ -- 2.17.1