diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 4ef16cb71865..81ee8ad5224a 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -13870,17 +13870,26 @@ bool DAGCombiner::MergeStoresOfConstantsOrVecElts(
              Val.getOpcode() == ISD::EXTRACT_SUBVECTOR)) {
           SDValue Vec = Val.getOperand(0);
           EVT MemVTScalarTy = MemVT.getScalarType();
+          SDValue Idx = Val.getOperand(1);
           // We may need to add a bitcast here to get types to line up.
           if (MemVTScalarTy != Vec.getValueType()) {
             unsigned Elts = Vec.getValueType().getSizeInBits() /
                             MemVTScalarTy.getSizeInBits();
+            if (Val.getValueType().isVector() && MemVT.isVector()) {
+              unsigned IdxC = cast<ConstantSDNode>(Idx)->getZExtValue();
+              unsigned NewIdx =
+                  ((uint64_t)IdxC * MemVT.getVectorNumElements()) / Elts;
+              Idx = DAG.getConstant(NewIdx, SDLoc(Val), Idx.getValueType());
+            }
+            if (!MemVT.isVector() && Val.getValueType().isVector())
+              dbgs() << "hit!\n";
             EVT NewVecTy =
                 EVT::getVectorVT(*DAG.getContext(), MemVTScalarTy, Elts);
             Vec = DAG.getBitcast(NewVecTy, Vec);
           }
           auto OpC = (MemVT.isVector()) ? ISD::EXTRACT_SUBVECTOR
                                         : ISD::EXTRACT_VECTOR_ELT;
-          Val = DAG.getNode(OpC, SDLoc(Val), MemVT, Vec, Val.getOperand(1));
+          Val = DAG.getNode(OpC, SDLoc(Val), MemVT, Vec, Idx);
         }
         Ops.push_back(Val);
       }
diff --git a/llvm/test/CodeGen/X86/merge-vector-stores-scale-idx-crash.ll b/llvm/test/CodeGen/X86/merge-vector-stores-scale-idx-crash.ll
new file mode 100644
index 000000000000..3bef9faee140
--- /dev/null
+++ b/llvm/test/CodeGen/X86/merge-vector-stores-scale-idx-crash.ll
@@ -0,0 +1,49 @@
+; RUN: llc < %s  -mtriple=x86_64-apple-osx10.14 -mattr=+avx2 | FileCheck %s
+
+; Check that we don't crash due creating invalid extract_subvector indices in store merging.
+; CHECK-LABEL: testfn
+; CHECK: retq
+define void @testfn(i32* nocapture %p) {
+  %v0 = getelementptr i32, i32* %p, i64 12
+  %1 = bitcast i32* %v0 to <2 x i64>*
+  %2 = bitcast i32* %v0 to <4 x i32>*
+  %3 = getelementptr <2 x i64>, <2 x i64>* %1, i64 -3
+  store <2 x i64> undef, <2 x i64>* %3, align 16
+  %4 = shufflevector <4 x i64> zeroinitializer, <4 x i64> undef, <2 x i32> <i32 0, i32 1>
+  %5 = getelementptr <2 x i64>, <2 x i64>* %1, i64 -2
+  store <2 x i64> %4, <2 x i64>* %5, align 16
+  %6 = shufflevector <8 x i32> zeroinitializer, <8 x i32> undef, <4 x i32> <i32 4, i32 5, i32 6, i32 7>
+  %7 = getelementptr <4 x i32>, <4 x i32>* %2, i64 -1
+  store <4 x i32> %6, <4 x i32>* %7, align 16
+  ret void
+}
+
+%struct.o.1.5.7.9.13.15.17.19.57 = type { [0 x %struct.d.0.4.6.8.12.14.16.18.56] }
+%struct.d.0.4.6.8.12.14.16.18.56 = type { float, float }
+
+; CHECK-LABEL: testfn_scalar
+; CHECK: retq
+define void @testfn_scalar(%struct.o.1.5.7.9.13.15.17.19.57* nocapture %j) local_unnamed_addr #0 align 2 {
+entry:
+  %0 = bitcast i64 undef to <2 x float>
+  br i1 undef, label %if.end, label %if.then
+
+if.then:                                          ; preds = %entry
+  unreachable
+
+if.end:                                           ; preds = %entry
+  %call.i.i17 = tail call <4 x float> @_Z1bv()
+  %1 = bitcast <4 x float> %call.i.i17 to <2 x i64>
+  %extract.i.i15 = extractelement <2 x i64> %1, i64 0
+  %arrayidx6 = getelementptr inbounds %struct.o.1.5.7.9.13.15.17.19.57, %struct.o.1.5.7.9.13.15.17.19.57* %j, i64 0, i32 0, i64 1
+  %2 = bitcast %struct.d.0.4.6.8.12.14.16.18.56* %arrayidx6 to i64*
+  store i64 %extract.i.i15, i64* %2, align 4
+  %r.sroa.0.0..sroa_cast12 = bitcast %struct.o.1.5.7.9.13.15.17.19.57* %j to <2 x float>*
+  store <2 x float> %0, <2 x float>* %r.sroa.0.0..sroa_cast12, align 4
+  ret void
+}
+
+declare <4 x float> @_Z1bv() local_unnamed_addr 
+
+attributes #0 = { nounwind "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="128" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2,+x87" "unsafe-fp-math"="false" "use-soft-float"="false" }
+