[llvm] [VPlan] Simplify BLEND %a, %b, NOT(%m) -> BLEND %b, %a, %m. (PR #128375)

[via llvm-commits]

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@@ -851,8 +851,20 @@ static void simplifyRecipe(VPRecipeBase &R, VPTypeAnalysis &TypeInfo) {
       return;
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ayalz wrote:

Unrelated, while we're here: above optimization checks for a single unique (non masked out) value, can hold a pointer rather than a SmallPtrSet. OTOH, can filter away all masked out values, even if more than one remains.

https://github.com/llvm/llvm-project/pull/128375