Index: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
===================================================================
--- llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -614,7 +614,8 @@
   /// represented as.
   void truncateToMinimalBitwidths(VPTransformState &State);
 
-  /// This function adds (StartIdx, StartIdx + Step, StartIdx + 2*Step, ...)
+  /// This function adds
+  /// (StartIdx * Step, (StartIdx + 1) * Step, (StartIdx + 2) * Step, ...)
   /// to each vector element of Val. The sequence starts at StartIndex.
   /// \p Opcode is relevant for FP induction variable.
   virtual Value *getStepVector(Value *Val, int StartIdx, Value *Step,
@@ -2456,8 +2457,10 @@
 Value *InnerLoopVectorizer::getStepVector(Value *Val, int StartIdx, Value *Step,
                                           Instruction::BinaryOps BinOp) {
   // Create and check the types.
-  auto *ValVTy = cast<FixedVectorType>(Val->getType());
-  int VLen = ValVTy->getNumElements();
+  assert(isa<FixedVectorType>(Val->getType()) &&
+         "Creation of scalable step vector not yet supported");
+  auto *ValVTy = cast<VectorType>(Val->getType());
+  ElementCount VLen = ValVTy->getElementCount();
 
   Type *STy = Val->getType()->getScalarType();
   assert((STy->isIntegerTy() || STy->isFloatingPointTy()) &&
@@ -2466,34 +2469,36 @@
 
   SmallVector<Constant *, 8> Indices;
 
-  if (STy->isIntegerTy()) {
-    // Create a vector of consecutive numbers from zero to VF.
-    for (int i = 0; i < VLen; ++i)
-      Indices.push_back(ConstantInt::get(STy, StartIdx + i));
+  // Create a vector of consecutive numbers from zero to VF.
+  VectorType *InitVecValVTy = ValVTy;
+  Type *InitVecValSTy = STy;
+  if (STy->isFloatingPointTy()) {
+    InitVecValSTy =
+        IntegerType::get(STy->getContext(), STy->getScalarSizeInBits());
+    InitVecValVTy = VectorType::get(InitVecValSTy, VLen);
+  }
+  Value *InitVec = Builder.CreateStepVector(InitVecValVTy);
+
+  // Add on StartIdx
+  Value *StartIdxSplat = Builder.CreateVectorSplat(
+      VLen, ConstantInt::get(InitVecValSTy, StartIdx));
+  InitVec = Builder.CreateAdd(InitVec, StartIdxSplat);
 
-    // Add the consecutive indices to the vector value.
-    Constant *Cv = ConstantVector::get(Indices);
-    assert(Cv->getType() == Val->getType() && "Invalid consecutive vec");
+  if (STy->isIntegerTy()) {
     Step = Builder.CreateVectorSplat(VLen, Step);
     assert(Step->getType() == Val->getType() && "Invalid step vec");
     // FIXME: The newly created binary instructions should contain nsw/nuw flags,
     // which can be found from the original scalar operations.
-    Step = Builder.CreateMul(Cv, Step);
+    Step = Builder.CreateMul(InitVec, Step);
     return Builder.CreateAdd(Val, Step, "induction");
   }
 
   // Floating point induction.
   assert((BinOp == Instruction::FAdd || BinOp == Instruction::FSub) &&
          "Binary Opcode should be specified for FP induction");
-  // Create a vector of consecutive numbers from zero to VF.
-  for (int i = 0; i < VLen; ++i)
-    Indices.push_back(ConstantFP::get(STy, (double)(StartIdx + i)));
-
-  // Add the consecutive indices to the vector value.
-  // Floating-point operations inherit FMF via the builder's flags.
-  Constant *Cv = ConstantVector::get(Indices);
+  InitVec = Builder.CreateUIToFP(InitVec, ValVTy);
   Step = Builder.CreateVectorSplat(VLen, Step);
-  Value *MulOp = Builder.CreateFMul(Cv, Step);
+  Value *MulOp = Builder.CreateFMul(InitVec, Step);
   return Builder.CreateBinOp(BinOp, Val, MulOp, "induction");
 }
 
@@ -4772,12 +4777,12 @@
     // phi as base and a vectorized version of the step value
     // (<step*0, ..., step*N>) as offset.
     for (unsigned Part = 0; Part < State.UF; ++Part) {
-      SmallVector<Constant *, 8> Indices;
+      Type *VecPhiType = VectorType::get(PhiType, State.VF);
+      Value *StartOffset =
+          ConstantInt::get(VecPhiType, Part * State.VF.getKnownMinValue());
       // Create a vector of consecutive numbers from zero to VF.
-      for (unsigned i = 0; i < State.VF.getKnownMinValue(); ++i)
-        Indices.push_back(
-            ConstantInt::get(PhiType, i + Part * State.VF.getKnownMinValue()));
-      Constant *StartOffset = ConstantVector::get(Indices);
+      StartOffset =
+          Builder.CreateAdd(StartOffset, Builder.CreateStepVector(VecPhiType));
 
       Value *GEP = Builder.CreateGEP(
           ScStValueType->getPointerElementType(), NewPointerPhi,