[PATCH] match.pd: (A>>bool) == 0 -> (unsigned)A) <= bool [PR119420]

[Daniel Henrique Barboza]

From: Daniel Barboza <daniel.barb...@oss.qualcomm.com>

Note that we're not adding its counterpart:

"(A>>bool) != 0 -> (unsigned)A) > bool"

Because it will collide with patterns that handles builtin_clz (e.g.
clz-complement-int.c tree-ssa test).

Bootstrapped and regression tested in x86.

        PR tree-optimization/119420

gcc/ChangeLog:

        * match.pd(`(A>>bool) EQ 0 -> (unsigned)A) LE bool`): New
        pattern.

gcc/testsuite/ChangeLog:

        * gcc.dg/tree-ssa/pr119420.c: New test.
---
 gcc/match.pd                             |  8 ++++++++
 gcc/testsuite/gcc.dg/tree-ssa/pr119420.c | 23 +++++++++++++++++++++++
 2 files changed, 31 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr119420.c

diff --git a/gcc/match.pd b/gcc/match.pd
index 7f16fd4e081..348e9f45a28 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -5367,6 +5367,14 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
       @0)))))
 #endif
 
+/* PR119420: (A >> bool) == 0 -> (unsigned)a <= (unsigned)bool;  */
+(simplify
+ (eq (rshift @0 zero_one_valued_p@1) integer_zerop)
+ (with {
+     tree utype = unsigned_type_for (TREE_TYPE (@0));
+  }
+  (le (convert:utype @0) (convert:utype @1))))
+
 /* Rewrite an LROTATE_EXPR by a constant into an
    RROTATE_EXPR by a new constant.  */
 (simplify
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr119420.c 
b/gcc/testsuite/gcc.dg/tree-ssa/pr119420.c
new file mode 100644
index 00000000000..3169650fe66
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr119420.c
@@ -0,0 +1,23 @@
+/* { dg-additional-options -O2 } */
+/* { dg-additional-options -fdump-tree-optimized } */
+
+int ll (signed a)
+{
+  int d = a >> 1;
+  return d == 0;
+}
+
+int ll1 (signed a)
+{
+  int d = a & ~1;
+  return d == 0;
+}
+
+int ll2 (signed a)
+{
+  unsigned aa = a;
+  return aa <= 1;
+}
+
+/* { dg-final { scan-tree-dump-times " >> " 0 optimized } } */
+/* { dg-final { scan-tree-dump-times " <= " 3 optimized } } */
-- 
2.43.0