[llvm] [VPlan] Use VPlan operand order for VPBlendRecipes. (PR #139475)

[Florian Hahn via llvm-commits]

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@@ -8538,36 +8538,30 @@ VPWidenIntOrFpInductionRecipe *VPRecipeBuilder::tryToOptimizeInductionTruncate(
   return nullptr;
 }
 
-VPBlendRecipe *VPRecipeBuilder::tryToBlend(PHINode *Phi,
-                                           ArrayRef<VPValue *> Operands) {
-  unsigned NumIncoming = Phi->getNumIncomingValues();
+VPBlendRecipe *VPRecipeBuilder::tryToBlend(VPWidenPHIRecipe *PhiR) {
+  unsigned NumIncoming = PhiR->getNumIncoming();
 
   // We know that all PHIs in non-header blocks are converted into selects, so
   // we don't have to worry about the insertion order and we can just use the
   // builder. At this point we generate the predication tree. There may be
   // duplications since this is a simple recursive scan, but future
   // optimizations will clean it up.
 
-  // Map incoming IR BasicBlocks to incoming VPValues, for lookup below.
-  // TODO: Add operands and masks in order from the VPlan predecessors.
-  DenseMap<BasicBlock *, VPValue *> VPIncomingValues;
-  for (const auto &[Idx, Pred] : enumerate(predecessors(Phi->getParent())))
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fhahn wrote:

They were set according to the order of incoming values/blocks in the original phi, which in some cases can be different to the order of predecessors in LLVM IR, which is causing the test changes.

https://github.com/llvm/llvm-project/pull/139475