[llvm] [LLVM][VPlan] Pick more optimal initial value for VPBlend. (PR #104019)

[Florian Hahn via llvm-commits]

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@@ -996,6 +1006,7 @@ static void simplifyRecipe(VPRecipeBase &R, VPTypeAnalysis &TypeInfo) {
                          m_LogicalAnd(m_VPValue(X1), m_Not(m_VPValue(Y1))))) &&
       X == X1 && Y == Y1) {
     R.getVPSingleValue()->replaceAllUsesWith(X);
+    R.eraseFromParent();
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fhahn wrote:

Probably best to wait until https://github.com/llvm/llvm-project/pull/93998 lands (work-list for simplifyRecipes), eager removal may remove recipes that may have been added to worklist earlier.

Once it has been switched to a work-list, we should be able to simplify, clean-up dead recipes and re-simplify the instructions that have any of their users removed.

As the other patterns at the moment aren't guarded by a use-count check, I don't think there should be differences at the moment from cleaning up early.

https://github.com/llvm/llvm-project/pull/104019