Index: llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
===================================================================
--- llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -2245,16 +2245,20 @@
 
   // Multiply the vectorization factor by the step using integer or
   // floating-point arithmetic as appropriate.
-  Value *ConstVF =
-      getSignedIntOrFpConstant(Step->getType(), VF.getKnownMinValue());
-  Value *Mul = Builder.CreateBinOp(MulOp, Step, ConstVF);
+  Type *StepType = Step->getType();
+  if (Step->getType()->isFloatingPointTy())
+    StepType = IntegerType::get(StepType->getContext(),
+                                StepType->getScalarSizeInBits());
+  Value *RuntimeVF = getRuntimeVF(Builder, StepType, VF);
+  if (Step->getType()->isFloatingPointTy())
+    RuntimeVF = Builder.CreateUIToFP(RuntimeVF, Step->getType());
+  Value *Mul = Builder.CreateBinOp(MulOp, Step, RuntimeVF);
 
   // Create a vector splat to use in the induction update.
   //
   // FIXME: If the step is non-constant, we create the vector splat with
   //        IRBuilder. IRBuilder can constant-fold the multiply, but it doesn't
   //        handle a constant vector splat.
-  assert(!VF.isScalable() && "scalable vectors not yet supported.");
   Value *SplatVF = isa<Constant>(Mul)
                        ? ConstantVector::getSplat(VF, cast<Constant>(Mul))
                        : Builder.CreateVectorSplat(VF, Mul);
@@ -2457,8 +2461,6 @@
 Value *InnerLoopVectorizer::getStepVector(Value *Val, int StartIdx, Value *Step,
                                           Instruction::BinaryOps BinOp) {
   // Create and check the types.
-  assert(isa<FixedVectorType>(Val->getType()) &&
-         "Creation of scalable step vector not yet supported");
   auto *ValVTy = cast<VectorType>(Val->getType());
   ElementCount VLen = ValVTy->getElementCount();
 
@@ -2533,19 +2535,43 @@
       Cost->isUniformAfterVectorization(cast<Instruction>(EntryVal), VF)
           ? 1
           : VF.getKnownMinValue();
-  assert((!VF.isScalable() || Lanes == 1) &&
-         "Should never scalarize a scalable vector");
   // Compute the scalar steps and save the results in State.
+  Type *IntStepTy = IntegerType::get(ScalarIVTy->getContext(),
+                                     ScalarIVTy->getScalarSizeInBits());
+  Type *VecIVTy = nullptr;
+  Value *UnitStepVec = nullptr, *SplatStep = nullptr, *SplatIV = nullptr;
+  if (Lanes > 1 && VF.isScalable()) {
+    VecIVTy = VectorType::get(ScalarIVTy, VF);
+    UnitStepVec = Builder.CreateStepVector(VectorType::get(IntStepTy, VF));
+    SplatStep = Builder.CreateVectorSplat(VF, Step);
+    SplatIV = Builder.CreateVectorSplat(VF, ScalarIV);
+  }
+
   for (unsigned Part = 0; Part < UF; ++Part) {
-    for (unsigned Lane = 0; Lane < Lanes; ++Lane) {
-      auto *IntStepTy = IntegerType::get(ScalarIVTy->getContext(),
-                                         ScalarIVTy->getScalarSizeInBits());
-      Value *StartIdx =
-          createStepForVF(Builder, ConstantInt::get(IntStepTy, Part), VF);
+    Value *StartIdx0 =
+        createStepForVF(Builder, ConstantInt::get(IntStepTy, Part), VF);
+
+    if (Lanes > 1 && VF.isScalable()) {
+      auto *SplatStartIdx = Builder.CreateVectorSplat(VF, StartIdx0);
+      auto *InitVec = Builder.CreateAdd(SplatStartIdx, UnitStepVec);
       if (ScalarIVTy->isFloatingPointTy())
-        StartIdx = Builder.CreateSIToFP(StartIdx, ScalarIVTy);
-      StartIdx = Builder.CreateBinOp(
-          AddOp, StartIdx, getSignedIntOrFpConstant(ScalarIVTy, Lane));
+        InitVec = Builder.CreateSIToFP(InitVec, VecIVTy);
+      auto *Mul = Builder.CreateBinOp(MulOp, InitVec, SplatStep);
+      auto *Add = Builder.CreateBinOp(AddOp, SplatIV, Mul);
+      State.set(Def, Add, Part);
+      recordVectorLoopValueForInductionCast(ID, EntryVal, Add, CastDef, State,
+                                            Part);
+      // It's useful to record the lane values too for the known minimum number
+      // of elements so we do those below. This improves the code quality when
+      // trying to extract the first element, for example.
+    }
+
+    if (ScalarIVTy->isFloatingPointTy())
+      StartIdx0 = Builder.CreateSIToFP(StartIdx0, ScalarIVTy);
+
+    for (unsigned Lane = 0; Lane < Lanes; ++Lane) {
+      Value *StartIdx = Builder.CreateBinOp(
+          AddOp, StartIdx0, getSignedIntOrFpConstant(ScalarIVTy, Lane));
       // The step returned by `createStepForVF` is a runtime-evaluated value
       // when VF is scalable. Otherwise, it should be folded into a Constant.
       assert((VF.isScalable() || isa<Constant>(StartIdx)) &&
@@ -4721,6 +4747,7 @@
   case InductionDescriptor::IK_PtrInduction: {
     // Handle the pointer induction variable case.
     assert(P->getType()->isPointerTy() && "Unexpected type.");
+    assert(!VF.isScalable() && "Currently unsupported for scalable vectors");
 
     if (Cost->isScalarAfterVectorization(P, State.VF)) {
       // This is the normalized GEP that starts counting at zero.
Index: llvm/test/Transforms/LoopVectorize/AArch64/sve-inductions.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/LoopVectorize/AArch64/sve-inductions.ll
@@ -0,0 +1,189 @@
+; RUN: opt -mtriple aarch64-linux-gnu -mattr=+sve -loop-vectorize -dce -instcombine < %s -S 2>%t | FileCheck %s
+
+; RUN: FileCheck --check-prefix=WARN --allow-empty %s <%t
+
+; If this check fails please read test/CodeGen/AArch64/README for instructions on how to resolve it.
+; WARN-NOT: warning
+
+; Test that we can add on the induction variable
+;   for (long long i = 0; i < n; i++) {
+;     a[i] = b[i] + i;
+;   }
+; with an unroll factor (interleave count) of 2.
+
+define void @add_ind64_unrolled(i64* noalias nocapture %a, i64* noalias nocapture readonly %b, i64 %n) {
+; CHECK-LABEL: @add_ind64_unrolled(
+; CHECK-NEXT:  entry:
+; CHECK: vector.body:
+; CHECK-NEXT:  %[[INDEX:.*]] = phi i64 [ 0, %vector.ph ], [ %{{.*}}, %vector.body ]
+; CHECK-NEXT:  %[[STEPVEC:.*]] = call <vscale x 2 x i64> @llvm.experimental.stepvector.nxv2i64()
+; CHECK-NEXT:  %[[TMP1:.*]] = insertelement <vscale x 2 x i64> poison, i64 %[[INDEX]], i32 0
+; CHECK-NEXT:  %[[IDXSPLT:.*]] = shufflevector <vscale x 2 x i64> %[[TMP1]], <vscale x 2 x i64> poison, <vscale x 2 x i32> zeroinitializer
+; CHECK-NEXT:  %[[VECIND1:.*]] = add <vscale x 2 x i64> %[[IDXSPLT]], %[[STEPVEC]]
+; CHECK-NEXT:  %[[VSCALE:.*]] = call i64 @llvm.vscale.i64()
+; CHECK-NEXT:  %[[EC:.*]] = shl i64 %[[VSCALE]], 1
+; CHECK-NEXT:  %[[TMP2:.*]] = insertelement <vscale x 2 x i64> poison, i64 %[[EC]], i32 0
+; CHECK-NEXT:  %[[ECSPLT:.*]] = shufflevector <vscale x 2 x i64> %[[TMP2]], <vscale x 2 x i64> poison, <vscale x 2 x i32> zeroinitializer
+; CHECK-NEXT:  %[[TMP3:.*]] = add <vscale x 2 x i64> %[[ECSPLT]], %[[STEPVEC]]
+; CHECK-NEXT:  %[[VECIND2:.*]] = add <vscale x 2 x i64> %[[IDXSPLT]], %[[TMP3]]
+; CHECK:       %[[LOAD1:.*]] = load <vscale x 2 x i64>
+; CHECK:       %[[LOAD2:.*]] = load <vscale x 2 x i64>
+; CHECK:       %[[STOREVAL1:.*]] = add nsw <vscale x 2 x i64> %[[LOAD1]], %[[VECIND1]]
+; CHECK:       %[[STOREVAL2:.*]] = add nsw <vscale x 2 x i64> %[[LOAD2]], %[[VECIND2]]
+; CHECK:       store <vscale x 2 x i64> %[[STOREVAL1]]
+; CHECK:       store <vscale x 2 x i64> %[[STOREVAL2]]
+
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %entry, %for.body
+  %i.08 = phi i64 [ %inc, %for.body ], [ 0, %entry ]
+  %arrayidx = getelementptr inbounds i64, i64* %b, i64 %i.08
+  %0 = load i64, i64* %arrayidx, align 8
+  %add = add nsw i64 %0, %i.08
+  %arrayidx1 = getelementptr inbounds i64, i64* %a, i64 %i.08
+  store i64 %add, i64* %arrayidx1, align 8
+  %inc = add nuw nsw i64 %i.08, 1
+  %exitcond.not = icmp eq i64 %inc, %n
+  br i1 %exitcond.not, label %exit, label %for.body, !llvm.loop !0
+
+exit:                                 ; preds = %for.body
+  ret void
+}
+
+
+; Test that we can vectorize a separate induction variable (not used for the branch)
+;   int r = 0;
+;   for (long long i = 0; i < n; i++) {
+;     a[i] = r;
+;     r += 2;
+;   }
+; with an unroll factor (interleave count) of 1.
+
+
+define void @add_unique_ind32(i32* noalias nocapture %a, i64 %n) {
+; CHECK-LABEL: @add_unique_ind32(
+; CHECK:    vector.ph:
+; CHECK:      %[[STEPVEC:.*]] = call <vscale x 4 x i32> @llvm.experimental.stepvector.nxv4i32()
+; CHECK-NEXT: %[[INDINIT:.*]] = shl <vscale x 4 x i32> %[[STEPVEC]], shufflevector (<vscale x 4 x i32> insertelement (<vscale x 4 x i32> undef, i32 1, i32 0), <vscale x 4 x i32> undef, <vscale x 4 x i32> zeroinitializer)
+; CHECK-NEXT: %[[VSCALE:.*]] = call i32 @llvm.vscale.i32()
+; CHECK-NEXT: %[[INC:.*]] = shl i32 %6, 3
+; CHECK-NEXT: %[[TMP:.*]] = insertelement <vscale x 4 x i32> poison, i32 %[[INC]], i32 0
+; CHECK-NEXT: %[[VECINC:.*]] = shufflevector <vscale x 4 x i32> %[[TMP]], <vscale x 4 x i32> poison, <vscale x 4 x i32> zeroinitializer
+; CHECK:    vector.body:
+; CHECK:      %[[VECIND:.*]] = phi <vscale x 4 x i32> [ %[[INDINIT]], %vector.ph ], [ %[[VECINDNXT:.*]], %vector.body ]
+; CHECK:      store <vscale x 4 x i32> %[[VECIND]]
+; CHECK:      %[[VECINDNXT]] = add <vscale x 4 x i32> %[[VECIND]], %[[VECINC]]
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %entry, %for.body
+  %i.08 = phi i64 [ %inc, %for.body ], [ 0, %entry ]
+  %r.07 = phi i32 [ %add, %for.body ], [ 0, %entry ]
+  %arrayidx = getelementptr inbounds i32, i32* %a, i64 %i.08
+  store i32 %r.07, i32* %arrayidx, align 4
+  %add = add nuw nsw i32 %r.07, 2
+  %inc = add nuw nsw i64 %i.08, 1
+  %exitcond.not = icmp eq i64 %inc, %n
+  br i1 %exitcond.not, label %exit, label %for.body, !llvm.loop !6
+
+exit:                                 ; preds = %for.body
+  ret void
+}
+
+
+; Test that we can vectorize a separate FP induction variable (not used for the branch)
+;   float r = 0;
+;   for (long long i = 0; i < n; i++) {
+;     a[i] = r;
+;     r += 2;
+;   }
+; with an unroll factor (interleave count) of 1.
+
+define void @add_unique_indf32(float* noalias nocapture %a, i64 %n) {
+; CHECK-LABEL: @add_unique_indf32(
+; CHECK:    vector.ph:
+; CHECK:      %[[STEPVEC:.*]] = call <vscale x 4 x i32> @llvm.experimental.stepvector.nxv4i32()
+; CHECK-NEXT: %[[TMP1:.*]] = uitofp <vscale x 4 x i32> %[[STEPVEC]] to <vscale x 4 x float>
+; CHECK-NEXT: %[[TMP2:.*]] = fmul <vscale x 4 x float> %[[TMP1]], shufflevector (<vscale x 4 x float> insertelement (<vscale x 4 x float> poison, float 2.000000e+00, i32 0), <vscale x 4 x float> poison, <vscale x 4 x i32> zeroinitializer)
+; CHECK-NEXT: %[[INDINIT:.*]] = fadd <vscale x 4 x float> %[[TMP2]], shufflevector (<vscale x 4 x float> insertelement (<vscale x 4 x float> poison, float 0.000000e+00, i32 0), <vscale x 4 x float> poison, <vscale x 4 x i32> zeroinitializer)
+; CHECK-NEXT: %[[VSCALE:.*]] = call i32 @llvm.vscale.i32()
+; CHECK-NEXT: %[[TMP3:.*]] = shl i32 %8, 2
+; CHECK-NEXT: %[[TMP4:.*]] = uitofp i32 %[[TMP3]] to float
+; CHECK-NEXT: %[[INC:.*]] = fmul float %[[TMP4]], 2.000000e+00
+; CHECK-NEXT: %[[TMP5:.*]] = insertelement <vscale x 4 x float> poison, float %[[INC]], i32 0
+; CHECK-NEXT: %[[VECINC:.*]] = shufflevector <vscale x 4 x float> %[[TMP5]], <vscale x 4 x float> poison, <vscale x 4 x i32> zeroinitializer
+; CHECK:   vector.body:
+; CHECK:     %[[VECIND:.*]] = phi <vscale x 4 x float> [ %[[INDINIT]], %vector.ph ], [ %[[VECINDNXT:.*]], %vector.body ]
+; CHECK:     store <vscale x 4 x float> %[[VECIND]]
+; CHECK:     %[[VECINDNXT]] = fadd <vscale x 4 x float> %[[VECIND]], %[[VECINC]]
+
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %entry, %for.body
+  %i.08 = phi i64 [ %inc, %for.body ], [ 0, %entry ]
+  %r.07 = phi float [ %add, %for.body ], [ 0.000000e+00, %entry ]
+  %arrayidx = getelementptr inbounds float, float* %a, i64 %i.08
+  store float %r.07, float* %arrayidx, align 4
+  %add = fadd float %r.07, 2.000000e+00
+  %inc = add nuw nsw i64 %i.08, 1
+  %exitcond.not = icmp eq i64 %inc, %n
+  br i1 %exitcond.not, label %exit, label %for.body, !llvm.loop !6
+
+exit:                                 ; preds = %for.body
+  ret void
+}
+
+; Test a case where the vectorised induction variable is used to
+; generate a mask:
+;   for (long long i = 0; i < n; i++) {
+;     if (i & 0x1)
+;       a[i] = b[i];
+;   }
+
+define void @cond_ind64(i32* noalias nocapture %a, i32* noalias nocapture readonly %b, i64 %n) {
+; CHECK-LABEL: @cond_ind64(
+; CHECK:    vector.body:
+; CHECK-NEXT: %[[INDEX:.*]] = phi i64 [ 0, %vector.ph ], [ %{{.*}}, %vector.body ]
+; CHECK:      %[[STEPVEC:.*]] = call <vscale x 4 x i64> @llvm.experimental.stepvector.nxv4i64()
+; CHECK-NEXT: %[[TMP1:.*]] = insertelement <vscale x 4 x i64> poison, i64 %[[INDEX]], i32 0
+; CHECK-NEXT: %[[IDXSPLT:.*]] = shufflevector <vscale x 4 x i64> %[[TMP1]], <vscale x 4 x i64> poison, <vscale x 4 x i32> zeroinitializer
+; CHECK-NEXT: %[[VECIND:.*]] = add <vscale x 4 x i64> %[[IDXSPLT]], %[[STEPVEC]]
+; CHECK-NEXT: %[[MASK:.*]] = trunc <vscale x 4 x i64> %[[VECIND]] to <vscale x 4 x i1>
+; CHECK:      %[[LOAD:.*]] = call <vscale x 4 x i32> @llvm.masked.load.nxv4i32.p0nxv4i32(<vscale x 4 x i32>* %{{.*}}, i32 4, <vscale x 4 x i1> %[[MASK]], <vscale x 4 x i32> poison)
+; CHECK:      call void @llvm.masked.store.nxv4i32.p0nxv4i32(<vscale x 4 x i32> %[[LOAD]], <vscale x 4 x i32>* %{{.*}}, i32 4, <vscale x 4 x i1> %[[MASK]])
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %entry, %for.inc
+  %i.08 = phi i64 [ %inc, %for.inc ], [ 0, %entry ]
+  %and = and i64 %i.08, 1
+  %tobool.not = icmp eq i64 %and, 0
+  br i1 %tobool.not, label %for.inc, label %if.then
+
+if.then:                                          ; preds = %for.body
+  %arrayidx = getelementptr inbounds i32, i32* %b, i64 %i.08
+  %0 = load i32, i32* %arrayidx, align 4
+  %arrayidx1 = getelementptr inbounds i32, i32* %a, i64 %i.08
+  store i32 %0, i32* %arrayidx1, align 4
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body, %if.then
+  %inc = add nuw nsw i64 %i.08, 1
+  %exitcond.not = icmp eq i64 %inc, %n
+  br i1 %exitcond.not, label %exit, label %for.body, !llvm.loop !6
+
+exit:                                 ; preds = %for.inc
+  ret void
+}
+
+!0 = distinct !{!0, !1, !2, !3, !4, !5}
+!1 = !{!"llvm.loop.mustprogress"}
+!2 = !{!"llvm.loop.vectorize.width", i32 2}
+!3 = !{!"llvm.loop.vectorize.scalable.enable", i1 true}
+!4 = !{!"llvm.loop.interleave.count", i32 2}
+!5 = !{!"llvm.loop.vectorize.enable", i1 true}
+!6 = distinct !{!6, !1, !7, !3, !8, !5}
+!7 = !{!"llvm.loop.vectorize.width", i32 4}
+!8 = !{!"llvm.loop.interleave.count", i32 1}