[VPlan] Use m_Intrinsic to match assumes/noalias_scope_decl (NFC).

Use pattern matching to check for intrinsics to slightly simplify code.

Author: fhahn

llvm/lib/Transforms/Vectorize/VPlanAnalysis.cpp

@@ -11,6 +11,7 @@
 #include "VPlanCFG.h"
 #include "VPlanDominatorTree.h"
 #include "VPlanHelpers.h"
+#include "VPlanPatternMatch.h"
 #include "llvm/ADT/PostOrderIterator.h"
 #include "llvm/ADT/TypeSwitch.h"
 #include "llvm/Analysis/ScalarEvolution.h"
@@ -19,6 +20,7 @@
 #include "llvm/IR/PatternMatch.h"
 
 using namespace llvm;
+using namespace VPlanPatternMatch;
 
 #define DEBUG_TYPE "vplan"
 
@@ -327,8 +329,7 @@ void llvm::collectEphemeralRecipesForVPlan(
            vp_depth_first_deep(Plan.getVectorLoopRegion()->getEntry()))) {
     for (VPRecipeBase &R : *VPBB) {
       auto *RepR = dyn_cast<VPReplicateRecipe>(&R);
-      if (!RepR || !match(RepR->getUnderlyingInstr(),
-                          PatternMatch::m_Intrinsic<Intrinsic::assume>()))
+      if (!RepR || !match(RepR, m_Intrinsic<Intrinsic::assume>()))
         continue;
       Worklist.push_back(RepR);
       EphRecipes.insert(RepR);

llvm/lib/Transforms/Vectorize/VPlanUnroll.cpp

@@ -275,11 +275,10 @@ void UnrollState::unrollRecipeByUF(VPRecipeBase &R) {
       remapOperands(&R, UF - 1);
       return;
     }
-    if (auto *II = dyn_cast<IntrinsicInst>(RepR->getUnderlyingValue())) {
-      if (II->getIntrinsicID() == Intrinsic::experimental_noalias_scope_decl) {
-        addUniformForAllParts(RepR);
-        return;
-      }
+    if (match(RepR,
+              m_Intrinsic<Intrinsic::experimental_noalias_scope_decl>())) {
+      addUniformForAllParts(RepR);
+      return;
     }
   }