This moves the match pattern `(x | y) & (~x ^ y)` over to use
bitwise_inverted_equal_p.
This now also allows to optmize comparisons and also catches the missed `(~x |
y) & (x ^ y)`
transformation into `~x & y`.
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
gcc/ChangeLog:
PR tree-optmization/111147
* match.pd (`(x | y) & (~x ^ y)`) Use bitwise_inverted_equal_p
instead of matching bit_not.
gcc/testsuite/ChangeLog:
PR tree-optmization/111147
* gcc.dg/tree-ssa/cmpbit-4.c: New test.
---
gcc/match.pd | 7 +++-
gcc/testsuite/gcc.dg/tree-ssa/cmpbit-4.c | 47 ++++++++++++++++++++++++
2 files changed, 52 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/cmpbit-4.c
diff --git a/gcc/match.pd b/gcc/match.pd
index e6bdc3149b6..47d2733211a 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1616,8 +1616,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
/* (x | y) & (~x ^ y) -> x & y */
(simplify
- (bit_and:c (bit_ior:c @0 @1) (bit_xor:c @1 (bit_not @0)))
- (bit_and @0 @1))
+ (bit_and:c (bit_ior:c @0 @1) (bit_xor:c @1 @2))
+ (with { bool wascmp; }
+ (if (bitwise_inverted_equal_p (@0, @2, wascmp)
+ && (!wascmp || element_precision (type) == 1))
+ (bit_and @0 @1))))
/* (~x | y) & (x | ~y) -> ~(x ^ y) */
(simplify
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-4.c
b/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-4.c
new file mode 100644
index 00000000000..cdba5d623af
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/cmpbit-4.c
@@ -0,0 +1,47 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized-raw" } */
+
+int g(int x, int y)
+{
+ int xp = ~x;
+ return (x | y) & (xp ^ y); // x & y
+}
+int g0(int x, int y)
+{
+ int xp = ~x;
+ return (xp | y) & (x ^ y); // ~x & y
+}
+
+_Bool gb(_Bool x, _Bool y)
+{
+ _Bool xp = !x;
+ return (x | y) & (xp ^ y); // x & y
+}
+_Bool gb0(_Bool x, _Bool y)
+{
+ _Bool xp = !x;
+ return (xp | y) & (x ^ y); // !x & y
+}
+
+
+_Bool gbi(int a, int b)
+{
+ _Bool x = a < 2;
+ _Bool y = b < 3;
+ _Bool xp = !x;
+ return (x | y) & (xp ^ y); // x & y
+}
+_Bool gbi0(int a, int b)
+{
+ _Bool x = a < 2;
+ _Bool y = b < 3;
+ _Bool xp = !x;
+ return (xp | y) & (x ^ y); // !x & y
+}
+
+/* All of these should be optimized to `x & y` or `~x & y` */
+/* { dg-final { scan-tree-dump-times "le_expr, " 3 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "gt_expr, " 1 "optimized" } } */
+/* { dg-final { scan-tree-dump-not "bit_xor_expr, " "optimized" } } */
+/* { dg-final { scan-tree-dump-times "bit_and_expr, " 6 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "bit_not_expr, " 2 "optimized" } } */
--
2.31.1
