[gcc r14-1883] tree-optimization/110278 - uns < (typeof uns)(uns != 0) is always false

[gcc r14-1883] tree-optimization/110278 - uns < (typeof uns)(uns != 0) is always false

[Richard Biener]

https://gcc.gnu.org/g:69b04fe7445c88edafd6983e28353a158e4314b5

commit r14-1883-g69b04fe7445c88edafd6983e28353a158e4314b5
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Jun 16 11:47:45 2023 +0200

    tree-optimization/110278 - uns < (typeof uns)(uns != 0) is always false
    
    The following adds two patterns simplifying comparisons,
    uns < (typeof uns)(uns != 0) is always false and x != (typeof x)(x == 0)
    is always true.
    
            PR tree-optimization/110278
            * match.pd (uns < (typeof uns)(uns != 0) -> false): New.
            (x != (typeof x)(x == 0) -> true): Likewise.

Diff:
---
 gcc/match.pd | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/gcc/match.pd b/gcc/match.pd
index b7baad6bf1b..2dd23826034 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -6410,6 +6410,17 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 	 (if (cmp == GT_EXPR)
 	  (lt (view_convert:st @0) { build_zero_cst (st); })))))))))))
 
+/* unsigned < (typeof unsigned)(unsigned != 0) is always false.  */
+(simplify
+ (lt:c @0 (convert (ne @0 integer_zerop)))
+ (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
+  { constant_boolean_node (false, type); }))
+
+/* x != (typeof x)(x == 0) is always true.  */
+(simplify
+ (ne:c @0 (convert (eq @0 integer_zerop)))
+ { constant_boolean_node (true, type); })
+
 (for cmp (unordered ordered unlt unle ungt unge uneq ltgt)
  /* If the second operand is NaN, the result is constant.  */
  (simplify