Index: ../lib/IR/Constants.cpp
===================================================================
--- ../lib/IR/Constants.cpp
+++ ../lib/IR/Constants.cpp
@@ -1912,8 +1912,16 @@
   assert(DestTy && "GEP indices invalid!");
   unsigned AS = C->getType()->getPointerAddressSpace();
   Type *ReqTy = DestTy->getPointerTo(AS);
-  if (VectorType *VecTy = dyn_cast<VectorType>(C->getType()))
-    ReqTy = VectorType::get(ReqTy, VecTy->getNumElements());
+
+  unsigned NumVecElts = 0;
+  if (C->getType()->isVectorTy())
+    NumVecElts = C->getType()->getVectorNumElements();
+  else for (auto Idx : Idxs)
+    if (Idx->getType()->isVectorTy())
+      NumVecElts = Idx->getType()->getVectorNumElements();
+
+  if (NumVecElts)
+    ReqTy = VectorType::get(ReqTy, NumVecElts);
 
   if (OnlyIfReducedTy == ReqTy)
     return nullptr;
@@ -1923,13 +1931,14 @@
   ArgVec.reserve(1 + Idxs.size());
   ArgVec.push_back(C);
   for (unsigned i = 0, e = Idxs.size(); i != e; ++i) {
-    assert(Idxs[i]->getType()->isVectorTy() == ReqTy->isVectorTy() &&
-           "getelementptr index type missmatch");
     assert((!Idxs[i]->getType()->isVectorTy() ||
-            ReqTy->getVectorNumElements() ==
-            Idxs[i]->getType()->getVectorNumElements()) &&
+            Idxs[i]->getType()->getVectorNumElements() == NumVecElts) &&
            "getelementptr index type missmatch");
-    ArgVec.push_back(cast<Constant>(Idxs[i]));
+
+    Constant *Idx = cast<Constant>(Idxs[i]);
+    if (NumVecElts && !Idxs[i]->getType()->isVectorTy())
+      Idx = ConstantVector::getSplat(NumVecElts, Idx);
+    ArgVec.push_back(Idx);
   }
   const ConstantExprKeyType Key(Instruction::GetElementPtr, ArgVec, 0,
                                 InBounds ? GEPOperator::IsInBounds : 0, None,
Index: ../test/Transforms/InstSimplify/vector_gep.ll
===================================================================
--- ../test/Transforms/InstSimplify/vector_gep.ll
+++ ../test/Transforms/InstSimplify/vector_gep.ll
@@ -53,3 +53,12 @@
 ; CHECK-LABEL: @test5
 ; CHECK-NEXT: ret <4 x i8*> getelementptr (i8, <4 x i8*> <i8* inttoptr (i64 1 to i8*), i8* inttoptr (i64 2 to i8*), i8* inttoptr (i64 3 to i8*), i8* inttoptr (i64 4 to i8*)>, <4 x i32> <i32 1, i32 1, i32 1, i32 1>)
 }
+
+@v = global [24 x [42 x [3 x i32]]] zeroinitializer, align 16
+
+define <16 x i32*> @test6() {
+; CHECK-LABEL: @test6
+; CHECK-NEXT: ret <16 x i32*> getelementptr ([24 x [42 x [3 x i32]]], [24 x [42 x [3 x i32]]]* @v, <16 x i64> zeroinitializer, <16 x i64> zeroinitializer, <16 x i64> <i64 0, i64 1, i64 2, i64 3, i64 4, i64 5, i64 6, i64 7, i64 8, i64 9, i64 10, i64 11, i64 12, i64 13, i64 14, i64 15>, <16 x i64> zeroinitializer)
+  %VectorGep = getelementptr [24 x [42 x [3 x i32]]], [24 x [42 x [3 x i32]]]* @v, i64 0, i64 0, <16 x i64> <i64 0, i64 1, i64 2, i64 3, i64 4, i64 5, i64 6, i64 7, i64 8, i64 9, i64 10, i64 11, i64 12, i64 13, i64 14, i64 15>, i64 0
+  ret <16 x i32*> %VectorGep
+}
\ No newline at end of file