MATCH: [PR111346] `X CMP MINMAX` pattern missing :c on CMP

I noticed this while working on other MINMAX optimizations. It was
hard to find a simplified testcase though because it was dependent on
the ssa name versions. Adding the `:c` to cmp allows the pattern to
be match for the case where minmax as the first operand of the comparison
rather than the second.

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

	PR tree-optimization/111346

gcc/ChangeLog:

	* match.pd (`X CMP MINMAX`): Add `:c` on the cmp part
	of the pattern

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/minmaxcmp-1.c: New test.

diff --git a/gcc/match.pd b/gcc/match.pd
index c7b6db4b5436619006243ce24943c778dc9da7fc..a60fe04885e74c033db9b2180b2f39d250926a60 100644 (file)
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3942,7 +3942,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 (for minmax (min     min     max     max     )
      cmp    (ge      lt      le      gt      )
  (simplify
-  (cmp @0 (minmax:c @0 @1))
+  (cmp:c @0 (minmax:c @0 @1))
   { constant_boolean_node (cmp == GE_EXPR || cmp == LE_EXPR, type); } ))
 
 /* Undo fancy ways of writing max/min or other ?: expressions, like

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/minmaxcmp-1.c b/gcc/testsuite/gcc.dg/tree-ssa/minmaxcmp-1.c
new file mode 100644 (file)
index 0000000..0706c02
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/minmaxcmp-1.c
@@ -0,0 +1,39 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized -fdump-tree-original" } */
+/* PR tree-optimization/111346 */
+
+int f();
+int g();
+
+_Bool test1(int a, int b)
+{
+        return ((a > b) ? a : b) >= a; // return 1;
+}
+_Bool test1_(int a, int b)
+{
+        return a <= ((a > b) ? a : b); // return 1;
+}
+/* test1 and test1_ should be able to optimize to `return 1;` during fold.  */
+/* { dg-final { scan-tree-dump-times "return 1;" 2 "original" } } */
+/* { dg-final { scan-tree-dump-not " MAX_EXPR " "original" } } */
+
+_Bool test2(int a, int b)
+{
+        a = f();
+        a = g();
+        int t = a;
+        if (t < b) t = b;
+        return t >= a; // return 1;
+}
+
+_Bool test2_(int a, int b)
+{
+        a = g();
+        int t = a;
+        if (t < b) t = b;
+        return t >= a; // return 1;
+}
+
+/* All of these should be optimized to just be the function calls and `return 1;` */
+/* { dg-final { scan-tree-dump-times "return 1;" 4 "optimized" } } */
+/* { dg-final { scan-tree-dump-not " MAX_EXPR " "optimized" } } */