Index: lib/CodeGen/GlobalISel/IRTranslator.cpp
===================================================================
--- lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -1067,7 +1067,16 @@
     EntryBuilder.buildConstant(Reg, 0);
   else if (auto GV = dyn_cast<GlobalValue>(&C))
     EntryBuilder.buildGlobalValue(Reg, GV);
-  else if (auto CE = dyn_cast<ConstantExpr>(&C)) {
+  else if (auto CAZ = dyn_cast<ConstantAggregateZero>(&C)) {
+    if (!CAZ->getType()->isVectorTy())
+      return false;
+    std::vector<unsigned> Ops;
+    for (unsigned i = 0; i < CAZ->getNumElements(); ++i) {
+      Constant &Elt = *CAZ->getElementValue(i);
+      Ops.push_back(getOrCreateVReg(Elt));
+    }
+    EntryBuilder.buildMerge(Reg, Ops);
+  } else if (auto CE = dyn_cast<ConstantExpr>(&C)) {
     switch(CE->getOpcode()) {
 #define HANDLE_INST(NUM, OPCODE, CLASS)                         \
       case Instruction::OPCODE: return translate##OPCODE(*CE, EntryBuilder);
Index: test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
===================================================================
--- test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
+++ test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll
@@ -1303,3 +1303,28 @@
   %res = extractelement <1 x i32> %vec, i32 0
   ret i32 %res
 }
+
+define <2 x i32> @test_constantaggzerovector_v2i32() {
+; CHECK-LABEL: name: test_constantaggzerovector_v2i32
+; CHECK: [[ZERO:%[0-9]+]](s32) = G_CONSTANT i32 0
+; CHECK: [[VEC:%[0-9]+]](<2 x s32>) = G_MERGE_VALUES [[ZERO]](s32), [[ZERO]](s32)
+; CHECK: %d0 = COPY [[VEC]](<2 x s32>)
+  ret <2 x i32> zeroinitializer
+}
+
+define <2 x float> @test_constantaggzerovector_v2f32() {
+; CHECK-LABEL: name: test_constantaggzerovector_v2f32
+; CHECK: [[ZERO:%[0-9]+]](s32) = G_FCONSTANT float 0.000000e+00
+; CHECK: [[VEC:%[0-9]+]](<2 x s32>) = G_MERGE_VALUES [[ZERO]](s32), [[ZERO]](s32)
+; CHECK: %d0 = COPY [[VEC]](<2 x s32>)
+  ret <2 x float> zeroinitializer
+}
+
+define i32 @test_constantaggzerovector_v3i32() {
+; CHECK-LABEL: name: test_constantaggzerovector_v3i32
+; CHECK: [[ZERO:%[0-9]+]](s32) = G_CONSTANT i32 0
+; CHECK: [[VEC:%[0-9]+]](<3 x s32>) = G_MERGE_VALUES [[ZERO]](s32), [[ZERO]](s32), [[ZERO]](s32)
+; CHECK: G_EXTRACT_VECTOR_ELT [[VEC]](<3 x s32>)
+  %elt = extractelement <3 x i32> zeroinitializer, i32 1
+  ret i32 %elt
+}