[VPlan][NFC] Make VPValue pointer const. (#101334)

Author: Mel-Chen

llvm/lib/Transforms/Vectorize/VPlan.cpp

@@ -1624,7 +1624,7 @@ VPValue *vputils::getOrCreateVPValueForSCEVExpr(VPlan &Plan, const SCEV *Expr,
   return Expanded;
 }
 
-bool vputils::isHeaderMask(VPValue *V, VPlan &Plan) {
+bool vputils::isHeaderMask(const VPValue *V, VPlan &Plan) {
   if (isa<VPActiveLaneMaskPHIRecipe>(V))
     return true;
 

llvm/lib/Transforms/Vectorize/VPlan.h

@@ -3799,12 +3799,12 @@ VPValue *getOrCreateVPValueForSCEVExpr(VPlan &Plan, const SCEV *Expr,
                                        ScalarEvolution &SE);
 
 /// Returns true if \p VPV is uniform after vectorization.
-inline bool isUniformAfterVectorization(VPValue *VPV) {
+inline bool isUniformAfterVectorization(const VPValue *VPV) {
   // A value defined outside the vector region must be uniform after
   // vectorization inside a vector region.
   if (VPV->isDefinedOutsideVectorRegions())
     return true;
-  VPRecipeBase *Def = VPV->getDefiningRecipe();
+  const VPRecipeBase *Def = VPV->getDefiningRecipe();
   assert(Def && "Must have definition for value defined inside vector region");
   if (auto Rep = dyn_cast<VPReplicateRecipe>(Def))
     return Rep->isUniform();
@@ -3816,7 +3816,7 @@ inline bool isUniformAfterVectorization(VPValue *VPV) {
 }
 
 /// Return true if \p V is a header mask in \p Plan.
-bool isHeaderMask(VPValue *V, VPlan &Plan);
+bool isHeaderMask(const VPValue *V, VPlan &Plan);
 } // end namespace vputils
 
 } // end namespace llvm