diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -620,9 +620,9 @@
   /// (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,
-                               Instruction::BinaryOps Opcode =
-                               Instruction::BinaryOpsEnd);
+  virtual Value *
+  getStepVector(Value *Val, Value *StartIdx, Value *Step,
+                Instruction::BinaryOps Opcode = Instruction::BinaryOpsEnd);
 
   /// Compute scalar induction steps. \p ScalarIV is the scalar induction
   /// variable on which to base the steps, \p Step is the size of the step, and
@@ -889,9 +889,9 @@
 
 private:
   Value *getBroadcastInstrs(Value *V) override;
-  Value *getStepVector(Value *Val, int StartIdx, Value *Step,
-                       Instruction::BinaryOps Opcode =
-                       Instruction::BinaryOpsEnd) override;
+  Value *getStepVector(
+      Value *Val, Value *StartIdx, Value *Step,
+      Instruction::BinaryOps Opcode = Instruction::BinaryOpsEnd) override;
   Value *reverseVector(Value *Vec) override;
 };
 
@@ -1119,6 +1119,13 @@
   return VF.isScalable() ? B.CreateVScale(EC) : EC;
 }
 
+static Value *getRuntimeVFAsFloat(IRBuilder<> &B, Type *FTy, ElementCount VF) {
+  assert(FTy->isFloatingPointTy() && "Expected floating point type!");
+  Type *IntTy = IntegerType::get(FTy->getContext(), FTy->getScalarSizeInBits());
+  Value *RuntimeVF = getRuntimeVF(B, IntTy, VF);
+  return B.CreateSIToFP(RuntimeVF, FTy);
+}
+
 void reportVectorizationFailure(const StringRef DebugMsg,
                                 const StringRef OREMsg, const StringRef ORETag,
                                 OptimizationRemarkEmitter *ORE, Loop *TheLoop,
@@ -2286,9 +2293,16 @@
     Step = Builder.CreateTrunc(Step, TruncType);
     Start = Builder.CreateCast(Instruction::Trunc, Start, TruncType);
   }
+
+  Value *Zero;
+  if (Start->getType()->isFloatingPointTy())
+    Zero = ConstantFP::get(Start->getType(), 0);
+  else
+    Zero = ConstantInt::get(Start->getType(), 0);
+
   Value *SplatStart = Builder.CreateVectorSplat(VF, Start);
   Value *SteppedStart =
-      getStepVector(SplatStart, 0, Step, II.getInductionOpcode());
+      getStepVector(SplatStart, Zero, Step, II.getInductionOpcode());
 
   // We create vector phi nodes for both integer and floating-point induction
   // variables. Here, we determine the kind of arithmetic we will perform.
@@ -2305,12 +2319,11 @@
   // Multiply the vectorization factor by the step using integer or
   // floating-point arithmetic as appropriate.
   Type *StepType = Step->getType();
+  Value *RuntimeVF;
   if (Step->getType()->isFloatingPointTy())
-    StepType = IntegerType::get(StepType->getContext(),
-                                StepType->getScalarSizeInBits());
-  Value *RuntimeVF = getRuntimeVF(Builder, StepType, VF);
-  if (Step->getType()->isFloatingPointTy())
-    RuntimeVF = Builder.CreateSIToFP(RuntimeVF, Step->getType());
+    RuntimeVF = getRuntimeVFAsFloat(Builder, StepType, VF);
+  else
+    RuntimeVF = getRuntimeVF(Builder, StepType, VF);
   Value *Mul = Builder.CreateBinOp(MulOp, Step, RuntimeVF);
 
   // Create a vector splat to use in the induction update.
@@ -2459,9 +2472,14 @@
     Value *Broadcasted = getBroadcastInstrs(ScalarIV);
     for (unsigned Part = 0; Part < UF; ++Part) {
       assert(!VF.isScalable() && "scalable vectors not yet supported.");
+      Value *StartIdx;
+      if (Step->getType()->isFloatingPointTy())
+        StartIdx = getRuntimeVFAsFloat(Builder, Step->getType(), VF * Part);
+      else
+        StartIdx = getRuntimeVF(Builder, Step->getType(), VF * Part);
+
       Value *EntryPart =
-          getStepVector(Broadcasted, VF.getKnownMinValue() * Part, Step,
-                        ID.getInductionOpcode());
+          getStepVector(Broadcasted, StartIdx, Step, ID.getInductionOpcode());
       State.set(Def, EntryPart, Part);
       if (Trunc)
         addMetadata(EntryPart, Trunc);
@@ -2517,7 +2535,8 @@
   buildScalarSteps(ScalarIV, Step, EntryVal, ID, Def, CastDef, State);
 }
 
-Value *InnerLoopVectorizer::getStepVector(Value *Val, int StartIdx, Value *Step,
+Value *InnerLoopVectorizer::getStepVector(Value *Val, Value *StartIdx,
+                                          Value *Step,
                                           Instruction::BinaryOps BinOp) {
   // Create and check the types.
   auto *ValVTy = cast<VectorType>(Val->getType());
@@ -2540,12 +2559,11 @@
   }
   Value *InitVec = Builder.CreateStepVector(InitVecValVTy);
 
-  // Add on StartIdx
-  Value *StartIdxSplat = Builder.CreateVectorSplat(
-      VLen, ConstantInt::get(InitVecValSTy, StartIdx));
-  InitVec = Builder.CreateAdd(InitVec, StartIdxSplat);
+  // Splat the StartIdx
+  Value *StartIdxSplat = Builder.CreateVectorSplat(VLen, StartIdx);
 
   if (STy->isIntegerTy()) {
+    InitVec = Builder.CreateAdd(InitVec, StartIdxSplat);
     Step = Builder.CreateVectorSplat(VLen, Step);
     assert(Step->getType() == Val->getType() && "Invalid step vec");
     // FIXME: The newly created binary instructions should contain nsw/nuw flags,
@@ -2558,6 +2576,8 @@
   assert((BinOp == Instruction::FAdd || BinOp == Instruction::FSub) &&
          "Binary Opcode should be specified for FP induction");
   InitVec = Builder.CreateUIToFP(InitVec, ValVTy);
+  InitVec = Builder.CreateFAdd(InitVec, StartIdxSplat);
+
   Step = Builder.CreateVectorSplat(VLen, Step);
   Value *MulOp = Builder.CreateFMul(InitVec, Step);
   return Builder.CreateBinOp(BinOp, Val, MulOp, "induction");
@@ -8308,21 +8328,19 @@
 
 Value *InnerLoopUnroller::getBroadcastInstrs(Value *V) { return V; }
 
-Value *InnerLoopUnroller::getStepVector(Value *Val, int StartIdx, Value *Step,
+Value *InnerLoopUnroller::getStepVector(Value *Val, Value *StartIdx,
+                                        Value *Step,
                                         Instruction::BinaryOps BinOp) {
   // When unrolling and the VF is 1, we only need to add a simple scalar.
   Type *Ty = Val->getType();
   assert(!Ty->isVectorTy() && "Val must be a scalar");
 
   if (Ty->isFloatingPointTy()) {
-    Constant *C = ConstantFP::get(Ty, (double)StartIdx);
-
     // Floating-point operations inherit FMF via the builder's flags.
-    Value *MulOp = Builder.CreateFMul(C, Step);
+    Value *MulOp = Builder.CreateFMul(StartIdx, Step);
     return Builder.CreateBinOp(BinOp, Val, MulOp);
   }
-  Constant *C = ConstantInt::get(Ty, StartIdx);
-  return Builder.CreateAdd(Val, Builder.CreateMul(C, Step), "induction");
+  return Builder.CreateAdd(Val, Builder.CreateMul(StartIdx, Step), "induction");
 }
 
 static void AddRuntimeUnrollDisableMetaData(Loop *L) {