[Bug ada/68590] [6 Regression] FAIL: gnat.dg/loop_optimization19.adb scan-tree-dump-not optimized "Index_Check"

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68590

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
The following avoids the issue in this PR

Index: gcc/match.pd
===================================================================
--- gcc/match.pd        (revision 231065)
+++ gcc/match.pd        (working copy)
@@ -1828,15 +1828,14 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)

 /* Simplify comparison of something with itself.  For IEEE
    floating-point, we can only do some of these simplifications.  */
-(simplify
- (eq @0 @0)
- (if (! FLOAT_TYPE_P (TREE_TYPE (@0))
-      || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (@0))))
-  { constant_boolean_node (true, type); }))
-(for cmp (ge le)
+(for cmp (eq ge le)
  (simplify
   (cmp @0 @0)
-  (eq @0 @0)))
+  (if (! FLOAT_TYPE_P (TREE_TYPE (@0))
+       || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (@0))))
+   { constant_boolean_node (true, type); }
+   (if (cmp != EQ_EXPR)
+    (eq @0 @0)))))
 (for cmp (ne gt lt)
  (simplify
   (cmp @0 @0)