[llvm] [LoopVectorize] Support vectorization of compressing patterns (PR #214491)

[Luke Lau via llvm-commits]

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@@ -2939,6 +2970,52 @@ class VPReductionPHIRecipe : public VPHeaderPHIRecipe, public VPIRFlags {
 #endif
 };
 
+/// A recipe for handling conditional induction PHIs. The start value is the
+/// first operand of the recipe, the incoming value from the backedge is the
+/// second operand, and the third operand is the step.
+class VPConditionalInductionPHIRecipe : public VPHeaderPHIRecipe {
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lukel97 wrote:

Is there anything special about a VPConditionalInductionPHIRecipe? Can we just use a VPInstruction::PHI?

https://github.com/llvm/llvm-project/pull/214491