[LV] Use PatternMatch in emitTransformedIndex (NFC)

Author: artagnon

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -2257,6 +2257,7 @@ emitTransformedIndex(IRBuilderBase &B, Value *Index, Value *StartValue,
                      Value *Step,
                      InductionDescriptor::InductionKind InductionKind,
                      const BinaryOperator *InductionBinOp) {
+  using namespace llvm::PatternMatch;
   Type *StepTy = Step->getType();
   Value *CastedIndex = StepTy->isIntegerTy()
                            ? B.CreateSExtOrTrunc(Index, StepTy)
@@ -2274,12 +2275,10 @@ emitTransformedIndex(IRBuilderBase &B, Value *Index, Value *StartValue,
   // cases only.
   auto CreateAdd = [&B](Value *X, Value *Y) {
     assert(X->getType() == Y->getType() && "Types don't match!");
-    if (auto *CX = dyn_cast<ConstantInt>(X))
-      if (CX->isZero())
-        return Y;
-    if (auto *CY = dyn_cast<ConstantInt>(Y))
-      if (CY->isZero())
-        return X;
+    if (match(X, m_ZeroInt()))
+      return Y;
+    if (match(Y, m_ZeroInt()))
+      return X;
     return B.CreateAdd(X, Y);
   };
 
@@ -2288,12 +2287,10 @@ emitTransformedIndex(IRBuilderBase &B, Value *Index, Value *StartValue,
   auto CreateMul = [&B](Value *X, Value *Y) {
     assert(X->getType()->getScalarType() == Y->getType() &&
            "Types don't match!");
-    if (auto *CX = dyn_cast<ConstantInt>(X))
-      if (CX->isOne())
-        return Y;
-    if (auto *CY = dyn_cast<ConstantInt>(Y))
-      if (CY->isOne())
-        return X;
+    if (match(X, m_One()))
+      return Y;
+    if (match(Y, m_One()))
+      return X;
     VectorType *XVTy = dyn_cast<VectorType>(X->getType());
     if (XVTy && !isa<VectorType>(Y->getType()))
       Y = B.CreateVectorSplat(XVTy->getElementCount(), Y);