https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97085
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
The following also works, and we then expand from
mask__31.28_102 = vect__50.25_95 != { 5, ... };
vect_patt_63.29_105 = VEC_COND_EXPR <mask__31.28_102, { 1, ... }, { 0, ...
}>;
diff --git a/gcc/match.pd b/gcc/match.pd
index 7d63bb973cb..e6dcdd0b855 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3521,6 +3521,17 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(if (optimize_vectors_before_lowering_p () && types_match (@0, @1))
(vec_cond (bit_and (bit_not @0) @1) @2 @3)))
+/* Canonicalize mask ? { 0, ... } : { -1, ...} to ~mask if the mask
+ types are compatible. */
+(simplify
+ (vec_cond @0 VECTOR_CST@1 VECTOR_CST@2)
+ (if (VECTOR_BOOLEAN_TYPE_P (type)
+ && types_match (type, TREE_TYPE (@0)))
+ (if (integer_zerop (@1) && integer_all_onesp (@2))
+ (bit_not @0)
+ (if (integer_all_onesp (@1) && integer_zerop (@2))
+ @0))))
+
/* Simplification moved from fold_cond_expr_with_comparison. It may also
be extended. */
/* This pattern implements two kinds simplification:
