[llvm] [VPlan] Add FinalIVValue VPInstruction. (PR #175651)

[Florian Hahn via llvm-commits]

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@@ -1008,8 +1009,9 @@ static VPValue *optimizeEarlyExitInductionUser(VPlan &Plan,
 static VPValue *optimizeLatchExitInductionUser(
     VPlan &Plan, VPTypeAnalysis &TypeInfo, VPBlockBase *PredVPBB, VPValue *Op,
     DenseMap<VPValue *, VPValue *> &EndValues, PredicatedScalarEvolution &PSE) {
-  VPValue *Incoming;
-  if (!match(Op, m_ExtractLastLaneOfLastPart(m_VPValue(Incoming))))
+  VPValue *Incoming = Op;
+  if (!match(Op, m_CombineOr(m_FinalIVValue(m_VPValue(), m_VPValue()),
+                             m_ExtractLastLaneOfLastPart(m_VPValue(Incoming)))))
     return nullptr;
 
   auto *WideIV = getOptimizableIVOf(Incoming, PSE);
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fhahn wrote:

Currently widened IVs can be truncated, but only if the truncate has the induction phi directly as operand currently. If the increment is truncated, we will use the widened IV still.

https://github.com/llvm/llvm-project/pull/175651