From: Andrew Pinski <apinski@marvell.com>
Date: Mon, 11 Sep 2023 15:05:10 +0000 (-0700)
Subject: MATCH: [PR111348] add missing :c to cmp in the `(a CMP b) ? minmax<a, c> : minmax... 
X-Git-Tag: basepoints/gcc-15~6284
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8fdf712a38422952bbcde7e22eabcf821e6676b3;p=thirdparty%2Fgcc.git

MATCH: [PR111348] add missing :c to cmp in the `(a CMP b) ? minmax<a, c> : minmax<b, c>` pattern

When I added this pattern in r14-337-gc43819a9b4cd, 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/111348

gcc/ChangeLog:

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

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/minmax-26.c: New test.
---

diff --git a/gcc/match.pd b/gcc/match.pd
index 209b0599382a..e96e385c6fa4 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -5417,7 +5417,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 (for minmax (min max)
  (for cmp (lt le gt ge ne)
   (simplify
-   (cond (cmp @1 @3) (minmax:c @1 @4) (minmax:c @2 @4))
+   (cond (cmp:c @1 @3) (minmax:c @1 @4) (minmax:c @2 @4))
    (with
     {
       tree_code code = minmax_from_comparison (cmp, @1, @2, @1, @3);
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmax-26.c b/gcc/testsuite/gcc.dg/tree-ssa/minmax-26.c
new file mode 100644
index 000000000000..e4b7412e7667
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/minmax-26.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized -fdump-tree-original" } */
+/* PR tree-optimization/111348 */
+
+int test1(int a, int b, int c)
+{
+        return (a > b) ? ((a > c) ? a : c) : ((b > c) ? b : c);
+}
+
+
+int test1_(int a, int b, int c)
+{
+        return (b < a) ? ((a > c) ? a : c) : ((b > c) ? b : c);
+}
+
+/* test1 and test1_ should be able to optimize to `MAX_EXPR <MAX_EXPR <a, b>, c>;` during fold.  */
+/* { dg-final { scan-tree-dump-times "MAX_EXPR <MAX_EXPR <a, b>, c>" 2 "original" } } */
+/* { dg-final { scan-tree-dump-not "b > a" "original" } } */
+/* { dg-final { scan-tree-dump-not "a > b" "original" } } */
+/* { dg-final { scan-tree-dump-times "MAX_EXPR " 4 "optimized" } } */
+/* { dg-final { scan-tree-dump-not "if " "optimized" } } */
+