From: Andrew Pinski <apinski@marvell.com>
Date: Mon, 11 Sep 2023 04:58:12 +0000 (-0700)
Subject: MATCH: [PR111349] add missing :c to cmp in the `(a CMP CST1) ? max<a,CST2> : a` pattern
X-Git-Tag: basepoints/gcc-15~6297
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b59e9de990a17bfd5fa7252b76339c35bff7f2e8;p=thirdparty%2Fgcc.git

MATCH: [PR111349] add missing :c to cmp in the `(a CMP CST1) ? max<a,CST2> : a` pattern

When I added this pattern in r14-1411-g17cca3c43e2f49, I had missed the :c on the cmp
part of the pattern meaning there might be some missing optimizations happening.
The testcase shows an example of the missed optmization.

Committed as obvious after a bootstrap/test on x86_64-linux-gnu.

	PR tree-optimization/111349

gcc/ChangeLog:

	* match.pd (`(a CMP CST1) ? max<a,CST2> : a`): Add :c on
	the cmp part of the pattern.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/minmax-25.c: New test.
---

diff --git a/gcc/match.pd b/gcc/match.pd
index a60fe04885e7..209b0599382a 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -5431,7 +5431,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 (for cmp    (gt  ge  lt  le)
      minmax (min min max max)
  (simplify
-  (cond (cmp @0 @1) (minmax:c@2 @0 @3) @4)
+  (cond (cmp:c @0 @1) (minmax:c@2 @0 @3) @4)
    (with
     {
       tree_code code = minmax_from_comparison (cmp, @0, @1, @0, @4);
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-25.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-25.c
new file mode 100644
index 000000000000..b7a5bfd4c193
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-25.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-optimized -fdump-tree-original" } */
+/* PR tree-optimization/111349 */
+
+int f();
+int g();
+
+int test1(int a, int b)
+{
+        return (a > b) ? ((a > b) ? a : b) : a;
+}
+
+int test1_(int a, int b)
+{
+        return (b < a) ? ((a > b) ? a : b) : a;
+}
+
+/* test1 and test1_ should be able to optimize to `return a;` during fold.  */
+/* { dg-final { scan-tree-dump-times "return a;" 2 "original" } } */
+/* { dg-final { scan-tree-dump-not " MAX_EXPR " "original" } } */
+/* { dg-final { scan-tree-dump-times "return a" 2 "optimized" } } */