[llvm] [VPlan] Remove MaskedCond and preserve SSA in early exits (PR #201784)

[Andrei Elovikov via llvm-commits]

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@@ -3380,6 +3368,12 @@ bool VPlanTransforms::handleUncountableEarlyExits(
           ExitIRI->getIncomingValueForBlock(EarlyExitingVPBB);
       VPValue *NewIncoming = IncomingVal;
       if (!isa<VPIRValue>(IncomingVal)) {
+        // Add phis so IncomingVal is defined on all paths to the latch.
+        DenseMap<VPBasicBlock *, VPValue *> Defs = {
+            {HeaderVPBB, Plan.getPoison(IncomingVal->getScalarType())}};
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eas wrote:

Is it possible that `IncomingVal` could have been speculated/hoisted to a preheader/entry block?

https://github.com/llvm/llvm-project/pull/201784