[PATCH] Fix 100864: `(a&!b) | b` is not opimized to `a | b` for comparisons

[Andrew Pinski <apinski@marvell.com>]

This adds a special case of the `(a&~b) | b` pattern where
`b` and `~b` are comparisons.

OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.

gcc/ChangeLog:

	PR tree-optimization/100864
	* match.pd ((~x & y) | x -> x | y): Add comparison variant.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/bitops-3.c: New test.
---
 gcc/match.pd                             | 17 +++++-
 gcc/testsuite/gcc.dg/tree-ssa/bitops-3.c | 67 ++++++++++++++++++++++++
 2 files changed, 83 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/bitops-3.c

diff --git a/gcc/match.pd b/gcc/match.pd
index bfd15d6cd4a..dd4a2df537d 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -1928,7 +1928,22 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
  /* (~x & y) | x -> x | y */
  (simplify
   (bitop:c (rbitop:c (bit_not @0) @1) @0)
-  (bitop @0 @1)))
+  (bitop @0 @1))
+ /* Similar but for comparisons which have been inverted already,
+    Note it is hard to simulate the inverted tcc_comparison due
+    NaNs; That is == and != are sometimes inversions and sometimes not.
+    So a double for loop is needed and then compare the inverse code
+    with the result of invert_tree_comparison is needed.
+    This works fine for vector compares as -1 and 0 are bitwise
+    inverses.  */
+ (for cmp (tcc_comparison)
+  (for icmp (tcc_comparison)
+   (simplify
+    (bitop:c (rbitop:c (icmp @0 @1) @2) (cmp@3 @0 @1))
+     (with { enum tree_code ic = invert_tree_comparison
+             (cmp, HONOR_NANS (@0)); }
+      (if (ic == icmp)
+       (bitop @3 @2)))))))
 
 /* ((x | y) & z) | x -> (z & y) | x */
 (simplify
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/bitops-3.c b/gcc/testsuite/gcc.dg/tree-ssa/bitops-3.c
new file mode 100644
index 00000000000..68fff4edce9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/bitops-3.c
@@ -0,0 +1,67 @@
+/* PR tree-optimization/100864 */
+
+/* { dg-do run } */
+/* { dg-options "-O1 -fdump-tree-optimized-raw" } */
+
+#define op_ne !=
+#define op_eq ==
+#define op_lt <
+#define op_le <=
+#define op_gt >
+#define op_ge >=
+
+#define operators(t) \
+t(ne) \
+t(eq) \
+t(lt) \
+t(le) \
+t(gt) \
+t(ge)
+
+#define cmpfunc(v, op) \
+__attribute__((noipa)) \
+_Bool func_##op##_##v(v int a, v int b, v _Bool e) \
+{ \
+  v _Bool c = (a op_##op b); \
+  v _Bool d = !c; \
+  return (e & d) | c; \
+}
+
+#define cmp_funcs(op) \
+cmpfunc(, op) \
+cmpfunc(volatile , op)
+
+operators(cmp_funcs)
+
+#define test(op) \
+if (func_##op##_ (a, b, e) != func_##op##_volatile (a, b, e)) \
+ __builtin_abort();
+ 
+int main()
+{
+  for(int a = -3; a <= 3; a++)
+    for(int b = -3; b <= 3; b++)
+      {
+	_Bool e = 0;
+	operators(test)
+	e = 1;
+	operators(test)
+      }
+  return 0;
+}
+
+/* Check to make sure we optimize `(a&!b) | b` -> `a | b`. */
+/* There are 6 different comparison operators testing here. */
+/* bit_not_expr and bit_and_expr should show up for each one (volatile). */
+/* Each operator should show up twice
+   (except for `!=` which shows up 2*6 (each tester) + 2 (the 2 loops) extra = 16). */
+/* bit_ior_expr will show up for each operator twice (non-volatile and volatile). */
+/* { dg-final { scan-tree-dump-times "ne_expr,"      16 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "eq_expr,"       2 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "lt_expr,"       2 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "le_expr,"       2 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "gt_expr,"       2 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "ge_expr,"       2 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "bit_not_expr,"  6 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "bit_and_expr,"  6 "optimized"} } */
+/* { dg-final { scan-tree-dump-times "bit_ior_expr," 12 "optimized"} } */
\ No newline at end of file
-- 
2.31.1