[PATCH] D144123: [LV] Add setStartValue to VPWidenIntOrFPInductionRecipe

[Michael Maitland via Phabricator via llvm-commits]

michaelmaitland created this revision.
michaelmaitland added reviewers: fhahn, nikolaypanchenko, reames.
Herald added subscribers: StephenFan, rogfer01, hiraditya.
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michaelmaitland requested review of this revision.
Herald added subscribers: llvm-commits, pcwang-thead, vkmr.
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VPWidenIntOrFPInductionRecipe is casted to VPHeaderPHIRecipe even
though it is not a VPHeaderPHIRecipe. Then setStartValue is called
on the VPWidenIntOrFPInductionRecipe which was casted to a class
that it does not inherit from. This bug was not caught because
VPHeaderPHIRecipe::setStartValue has the same body that *should*
have existed in VPWidenIntOrFPInductionRecipe. This patch
casts to the correct Recipe type and calls the correct
setStartValue function.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D144123

Files:
  llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
  llvm/lib/Transforms/Vectorize/VPlan.h


Index: llvm/lib/Transforms/Vectorize/VPlan.h
===================================================================
--- llvm/lib/Transforms/Vectorize/VPlan.h
+++ llvm/lib/Transforms/Vectorize/VPlan.h
@@ -1061,6 +1061,9 @@
   VPValue *getStartValue() { return getOperand(0); }
   const VPValue *getStartValue() const { return getOperand(0); }
 
+  /// Sets the start value of the induction
+  void setStartValue(VPValue *V) { setOperand(0, V); }
+
   /// Returns the step value of the induction.
   VPValue *getStepValue() { return getOperand(1); }
   const VPValue *getStepValue() const { return getOperand(1); }
Index: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
===================================================================
--- llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -10467,7 +10467,10 @@
           }
           assert(ResumeV && "Must have a resume value");
           VPValue *StartVal = BestEpiPlan.getOrAddExternalDef(ResumeV);
-          cast<VPHeaderPHIRecipe>(&R)->setStartValue(StartVal);
+          if (auto *PhiR = dyn_cast<VPHeaderPHIRecipe>(&R))
+            PhiR->setStartValue(StartVal);
+          else if (auto *PhiR = dyn_cast<VPWidenIntOrFpInductionRecipe>(&R))
+            PhiR->setStartValue(StartVal);
         }
 
         LVP.executePlan(EPI.EpilogueVF, EPI.EpilogueUF, BestEpiPlan, EpilogILV,


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