[VPlan] Update ::onlyScalarsGenerated to take IsScalable bool (NFCI).

Instead of passing in a full VF, just pass IsScalable as bool.

Author: fhahn

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -9237,7 +9237,7 @@ void VPWidenPointerInductionRecipe::execute(VPTransformState &State) {
   auto *IVR = getParent()->getPlan()->getCanonicalIV();
   PHINode *CanonicalIV = cast<PHINode>(State.get(IVR, 0));
 
-  if (onlyScalarsGenerated(State.VF)) {
+  if (onlyScalarsGenerated(State.VF.isScalable())) {
     // This is the normalized GEP that starts counting at zero.
     Value *PtrInd = State.Builder.CreateSExtOrTrunc(
         CanonicalIV, IndDesc.getStep()->getType());

llvm/lib/Transforms/Vectorize/VPlan.cpp

@@ -854,7 +854,7 @@ void VPlan::execute(VPTransformState *State) {
         auto *WidenPhi = cast<VPWidenPointerInductionRecipe>(&R);
         // TODO: Split off the case that all users of a pointer phi are scalar
         // from the VPWidenPointerInductionRecipe.
-        if (WidenPhi->onlyScalarsGenerated(State->VF))
+        if (WidenPhi->onlyScalarsGenerated(State->VF.isScalable()))
           continue;
 
         auto *GEP = cast<GetElementPtrInst>(State->get(WidenPhi, 0));

llvm/lib/Transforms/Vectorize/VPlan.h

@@ -1745,7 +1745,7 @@ class VPWidenPointerInductionRecipe : public VPHeaderPHIRecipe {
   void execute(VPTransformState &State) override;
 
   /// Returns true if only scalar values will be generated.
-  bool onlyScalarsGenerated(ElementCount VF);
+  bool onlyScalarsGenerated(bool IsScalable);
 
   /// Returns the induction descriptor for the recipe.
   const InductionDescriptor &getInductionDescriptor() const { return IndDesc; }
@@ -2966,6 +2966,9 @@ class VPlan {
   }
 
   bool hasVF(ElementCount VF) { return VFs.count(VF); }
+  bool hasScalableVF() {
+    return any_of(VFs, [](ElementCount VF) { return VF.isScalable(); });
+  }
 
   bool hasScalarVFOnly() const { return VFs.size() == 1 && VFs[0].isScalar(); }
 

llvm/lib/Transforms/Vectorize/VPlanRecipes.cpp

@@ -1650,9 +1650,9 @@ bool VPCanonicalIVPHIRecipe::isCanonical(
   return StepC && StepC->isOne();
 }
 
-bool VPWidenPointerInductionRecipe::onlyScalarsGenerated(ElementCount VF) {
+bool VPWidenPointerInductionRecipe::onlyScalarsGenerated(bool IsScalable) {
   return IsScalarAfterVectorization &&
-         (!VF.isScalable() || vputils::onlyFirstLaneUsed(this));
+         (!IsScalable || vputils::onlyFirstLaneUsed(this));
 }
 
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)