[llvm] [VPlan] Introduce ComputeReductionResult VPInstruction opcode. (PR #70253)

[via llvm-commits]

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@@ -8992,7 +8852,25 @@ void LoopVectorizationPlanner::adjustRecipesForReductions(
   SmallVector<VPReductionPHIRecipe *> InLoopReductionPhis;
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ayalz wrote:

Worth explaining what is happening here, before it was only collecting InLoopReductionPhis.

https://github.com/llvm/llvm-project/pull/70253