[llvm] [VPlan] Add VPIRInstruction, use for exit block live-outs. (PR #100735)

[via llvm-commits]

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@@ -339,6 +339,7 @@ class VPDef {
     VPBranchOnMaskSC,
     VPDerivedIVSC,
     VPExpandSCEVSC,
+    VPIRInstructionSC,
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ayalz wrote:

It's also for PredInstPhi, a non-loop-header if-then hammock phi of a replicate region. It should be for all phi's planned to be generated - to help keep them together at the start of their basic block.
Related thought - perhaps also worth checking, when fusing together two VPBB's, that the second is free of phi recipes.

https://github.com/llvm/llvm-project/pull/100735