[VPlan] Remove dead IsEpilogueVec argument from prepareToExecute (NFC).

Author: fhahn

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -7773,9 +7773,9 @@ SCEV2ValueTy LoopVectorizationPlanner::executePlan(
   //===------------------------------------------------===//
 
   // 2. Copy and widen instructions from the old loop into the new loop.
-  BestVPlan.prepareToExecute(
-      ILV.getTripCount(), ILV.getOrCreateVectorTripCount(nullptr),
-      CanonicalIVStartValue, State, IsEpilogueVectorization);
+  BestVPlan.prepareToExecute(ILV.getTripCount(),
+                             ILV.getOrCreateVectorTripCount(nullptr),
+                             CanonicalIVStartValue, State);
 
   BestVPlan.execute(&State);
 

llvm/lib/Transforms/Vectorize/VPlan.cpp

@@ -724,8 +724,7 @@ VPlanPtr VPlan::createInitialVPlan(const SCEV *TripCount, ScalarEvolution &SE) {
 
 void VPlan::prepareToExecute(Value *TripCountV, Value *VectorTripCountV,
                              Value *CanonicalIVStartValue,
-                             VPTransformState &State,
-                             bool IsEpilogueVectorization) {
+                             VPTransformState &State) {
   // Check if the backedge taken count is needed, and if so build it.
   if (BackedgeTakenCount && BackedgeTakenCount->getNumUsers()) {
     IRBuilder<> Builder(State.CFG.PrevBB->getTerminator());

llvm/lib/Transforms/Vectorize/VPlan.h

@@ -2571,8 +2571,7 @@ class VPlan {
 
   /// Prepare the plan for execution, setting up the required live-in values.
   void prepareToExecute(Value *TripCount, Value *VectorTripCount,
-                        Value *CanonicalIVStartValue, VPTransformState &State,
-                        bool IsEpilogueVectorization);
+                        Value *CanonicalIVStartValue, VPTransformState &State);
 
   /// Generate the IR code for this VPlan.
   void execute(VPTransformState *State);