tree-optimization/103356 Add missing (~a) == b folding for _Bool
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 tree-optimization/103356
gcc/ChangeLog:
* match.pd: ((~a) == b -> a ^ b): New pattern.
gcc/testsuite/ChangeLog:
* gcc.dg/pr103356-1.c: New test.
diff --git a/gcc/match.pd b/gcc/match.pd
index a4d1386..67a0a68 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1999,6 +1999,13 @@
&& 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 0000000..61d0b81
--- /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" } } */
