match.pd: A ^ ((A ^ B) & -(C cmp D)) -> (C cmp D) ? B : A simplification [PR94786]

We already have x - ((x - y) & -(z < w)) and
x + ((y - x) & -(z < w)) simplifications, this one adds
x ^ ((x ^ y) & -(z < w)) (not merged using for because of the
:c that can be present on bit_xor and can't on minus).

2020-05-08  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/94786
	* match.pd (A ^ ((A ^ B) & -(C cmp D)) -> (C cmp D) ? B : A): New
	simplification.

	* gcc.dg/tree-ssa/pr94786.c: New test.

4 files changed, 85 insertions, 0 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9a380a5..5373046 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
 2020-05-08  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/94786
+	* match.pd (A ^ ((A ^ B) & -(C cmp D)) -> (C cmp D) ? B : A): New
+	simplification.
+
 	PR target/94857
 	* config/i386/i386.md (peephole2 after *add<mode>3_cc_overflow_1): New
 	define_peephole2.
diff --git a/gcc/match.pd b/gcc/match.pd
index e8c53e3..58a4ac6 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -2800,6 +2800,18 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
        && (TYPE_PRECISION (TREE_TYPE (@4)) >= TYPE_PRECISION (type)
 	   || !TYPE_UNSIGNED (TREE_TYPE (@4)))
        && (GIMPLE || !TREE_SIDE_EFFECTS (@1)))
+   (cond (cmp @2 @3) @1 @0)))
+ /* Similarly with ^ instead of - though in that case with :c.  */
+ (simplify
+  (bit_xor:c @0 (bit_and:c (bit_xor:c @0 @1)
+			   (convert? (negate@4 (convert? (cmp@5 @2 @3))))))
+  (if (INTEGRAL_TYPE_P (type)
+       && INTEGRAL_TYPE_P (TREE_TYPE (@4))
+       && TREE_CODE (TREE_TYPE (@4)) != BOOLEAN_TYPE
+       && INTEGRAL_TYPE_P (TREE_TYPE (@5))
+       && (TYPE_PRECISION (TREE_TYPE (@4)) >= TYPE_PRECISION (type)
+	   || !TYPE_UNSIGNED (TREE_TYPE (@4)))
+       && (GIMPLE || !TREE_SIDE_EFFECTS (@1)))
    (cond (cmp @2 @3) @1 @0))))
 
 /* Simplifications of shift and rotates.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index db0a837..b95696f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2020-05-08  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/94786
+	* gcc.dg/tree-ssa/pr94786.c: New test.
+
 	PR target/94857
 	* gcc.target/i386/pr94857.c: New test.
 
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr94786.c b/gcc/testsuite/gcc.dg/tree-ssa/pr94786.c
new file mode 100644
index 0000000..beb88da
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr94786.c
@@ -0,0 +1,66 @@
+/* PR tree-optimization/94786 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* { dg-final { scan-tree-dump-times "MIN_EXPR <" 4 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "MAX_EXPR <" 4 "optimized" } } */
+
+static inline unsigned
+umax1 (unsigned a, unsigned b)
+{
+  return a ^ ((a ^ b) & -(a < b));
+}
+
+static inline unsigned
+umin1 (unsigned a, unsigned b)
+{
+  return a ^ ((a ^ b) & -(a > b));
+}
+
+static inline int
+smax1 (int a, int b)
+{
+  return a ^ ((a ^ b) & -(a < b));
+}
+
+static inline int
+smin1 (int a, int b)
+{
+  return a ^ ((a ^ b) & -(a > b));
+}
+
+static inline unsigned long long
+umax2 (unsigned long long a, unsigned long long b)
+{
+  return a ^ ((a ^ b) & -(a <= b));
+}
+
+static inline unsigned long long
+umin2 (unsigned long long a, unsigned long long b)
+{
+  return a ^ ((a ^ b) & -(a >= b));
+}
+
+static inline long long
+smax2 (long long a, long long b)
+{
+  return a ^ ((a ^ b) & -(a <= b));
+}
+
+static inline long long
+smin2 (long long a, long long b)
+{
+  return a ^ ((a ^ b) & -(a >= b));
+}
+
+void
+test (unsigned *x, int *y, unsigned long long *z, long long *w)
+{
+  x[2] = umax1 (x[0], x[1]);
+  x[5] = umin1 (x[2], x[3]);
+  y[2] = smax1 (y[0], y[1]);
+  y[5] = smin1 (y[2], y[3]);
+  z[2] = umax2 (z[0], z[1]);
+  z[5] = umin2 (z[2], z[3]);
+  w[2] = smax2 (w[0], w[1]);
+  w[5] = smin2 (w[2], w[3]);
+}