[llvm] [VPlan] Create AnyOf and FindIV resume adjustments in the epilogue plan. (PR #227882)

[Florian Hahn via llvm-commits]

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@@ -7433,41 +7431,40 @@ static SmallVector<Instruction *> preparePlanForEpilogueVectorLoop(
       });
 
       RecurKind RK = ReductionPhi->getRecurrenceKind();
+      ResumeVPV = Plan.getOrAddLiveIn(ResumeForEpi->getUnderlyingValue());
       if (RecurrenceDescriptor::isAnyOfRecurrenceKind(RK) || IsFindIV) {
-        auto *ResumePhi = cast<PHINode>(ResumeV);
         VPValue *BypassOp = ResumeForEpi->getOperand(1);
         assert((isa<VPIRValue>(BypassOp) ||
                 VPlanPatternMatch::match(
                     BypassOp,
                     m_VPInstruction<Instruction::Freeze>(m_VPValue()))) &&
                "expected live-in or Freeze");
-        Value *StartV = BypassOp->getUnderlyingValue();
-        IRBuilder<> Builder(ResumePhi->getParent(),
-                            ResumePhi->getParent()->getFirstNonPHIIt());
-
+        VPValue *StartV = Plan.getOrAddLiveIn(BypassOp->getUnderlyingValue());
         if (RecurrenceDescriptor::isAnyOfRecurrenceKind(RK)) {
           // VPReductionPHIRecipes for AnyOf reductions expect a boolean as
           // start value; compare the final value from the main vector loop
           // to the start value.
-          ResumeV = Builder.CreateICmpNE(ResumeV, StartV);
-          if (auto *I = dyn_cast<Instruction>(ResumeV))
-            InstsToMove.push_back(I);
+          ResumeVPV = PHBuilder.createICmp(CmpInst::ICMP_NE, ResumeVPV, StartV);
         } else {
-          assert(SentinelVPV && "expected to find icmp using RdxResult");
-          if (auto *FreezeI = dyn_cast<FreezeInst>(StartV))
-            ToFrozen[FreezeI->getOperand(0)] = StartV;
-
-          // Adjust resume: select(icmp eq ResumeV, StartV), Sentinel, ResumeV
-          Value *Cmp = Builder.CreateICmpEQ(ResumeV, StartV);
-          if (auto *I = dyn_cast<Instruction>(Cmp))
-            InstsToMove.push_back(I);
-          ResumeV = Builder.CreateSelect(Cmp, SentinelVPV->getLiveInIRValue(),
-                                         ResumeV);
-          if (auto *I = dyn_cast<Instruction>(ResumeV))
-            InstsToMove.push_back(I);
+          assert(isa<VPIRValue>(SentinelVPV) &&
+                 "sentinel must be a live-in to be used in the preheader");
+          VPValue *OrigStart;
+          if (VPlanPatternMatch::match(
+                  BypassOp, VPlanPatternMatch::m_Freeze(m_VPValue(OrigStart))))
+            ToFrozen[Plan.getOrAddLiveIn(cast<VPIRValue>(OrigStart))] = StartV;
+
+          // Adjust resume: select(icmp eq ResumeVPV, StartV), Sentinel,
+          // ResumeVPV
+          VPValue *Cmp =
+              PHBuilder.createICmp(CmpInst::ICMP_EQ, ResumeVPV, StartV);
+          ResumeVPV = PHBuilder.createSelect(Cmp, SentinelVPV, ResumeVPV);
         }
+        // TODO: materializeBroadcasts does not cover values in the vector
+        // preheader.
+        ReductionPhi->setStartValue(
+            PHBuilder.createNaryOp(VPInstruction::Broadcast, {ResumeVPV}));
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fhahn wrote:

done thanks

https://github.com/llvm/llvm-project/pull/227882