Index: llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
===================================================================
--- llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
+++ llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
@@ -176,6 +176,13 @@
       if (auto *AggrC = dyn_cast<ConstantAggregate>(Op)) {
         SmallVector<Value *> Args(AggrC->op_begin(), AggrC->op_end());
         BuildCompositeIntrinsic(AggrC, Args);
+      } else if (isa<UndefValue>(Op) && Op->getType()->isAggregateType()) {
+        auto *AggrC = dyn_cast<Constant>(Op);
+        SmallVector<Value *> Args;
+        unsigned Idx = 0;
+        while (auto Elt = AggrC->getAggregateElement(Idx++))
+          Args.push_back(Elt);
+        BuildCompositeIntrinsic(AggrC, Args);
       } else if (auto *AggrC = dyn_cast<ConstantDataArray>(Op)) {
         SmallVector<Value *> Args;
         for (unsigned i = 0; i < AggrC->getNumElements(); ++i)
Index: llvm/test/CodeGen/SPIRV/instructions/call-complex-function.ll
===================================================================
--- llvm/test/CodeGen/SPIRV/instructions/call-complex-function.ll
+++ llvm/test/CodeGen/SPIRV/instructions/call-complex-function.ll
@@ -1,28 +1,30 @@
 ; RUN: llc -O0 -mtriple=spirv32-unknown-unknown %s -o - | FileCheck %s
 
-; CHECK-DAG: OpName [[FUN:%.+]] "fun"
-; CHECK-DAG: OpName [[FOO:%.+]] "foo"
-; CHECK-DAG: OpName [[GOO:%.+]] "goo"
+; CHECK-DAG: OpName %[[#FUN:]] "fun"
+; CHECK-DAG: OpName %[[#FOO:]] "foo"
+; CHECK-DAG: OpName %[[#GOO:]] "goo"
 
 ; CHECK-NOT: DAG-FENCE
 
-; CHECK-DAG: [[I16:%.+]] = OpTypeInt 16
-; CHECK-DAG: [[I32:%.+]] = OpTypeInt 32
-; CHECK-DAG: [[I64:%.+]] = OpTypeInt 64
-; CHECK-DAG: [[FN3:%.+]] = OpTypeFunction [[I32]] [[I32]] [[I16]] [[I64]]
-; CHECK-DAG: [[PAIR:%.+]] = OpTypeStruct [[I32]] [[I16]]
-; CHECK-DAG: [[FN1:%.+]] = OpTypeFunction [[I32]] [[I32]]
-; CHECK-DAG: [[FN2:%.+]] = OpTypeFunction [[I32]] [[PAIR]] [[I64]]
+; CHECK-DAG: %[[#I16:]] = OpTypeInt 16
+; CHECK-DAG: %[[#I32:]] = OpTypeInt 32
+; CHECK-DAG: %[[#I64:]] = OpTypeInt 64
+; CHECK-DAG: %[[#FN3:]] = OpTypeFunction %[[#I32]] %[[#I32]] %[[#I16]] %[[#I64]]
+; CHECK-DAG: %[[#PAIR:]] = OpTypeStruct %[[#I32]] %[[#I16]]
+; CHECK-DAG: %[[#FN1:]] = OpTypeFunction %[[#I32]] %[[#I32]]
+; CHECK-DAG: %[[#FN2:]] = OpTypeFunction %[[#I32]] %[[#PAIR]] %[[#I64]]
 ;; According to the Specification, the OpUndef can be defined in Function.
 ;; But the Specification also recommends defining it here. So we enforce that.
-; CHECK-DAG: [[UNDEF:%.+]] = OpUndef [[PAIR]]
+; CHECK-DAG: %[[#UNDEF1:]] = OpUndef %[[#I32]]
+; CHECK-DAG: %[[#UNDEF2:]] = OpUndef %[[#I16]]
+; CHECK-DAG: %[[#COMPOSITE:]] = OpConstantComposite %[[#PAIR]] %[[#UNDEF1]] %[[#UNDEF2]]
 
 
 declare i32 @fun(i32 %value)
 
 ;; Check for @fun declaration
-; CHECK:      [[FUN]] = OpFunction [[I32]] None [[FN1]]
-; CHECK-NEXT: OpFunctionParameter [[I32]]
+; CHECK:      %[[#FUN]] = OpFunction %[[#I32]] None %[[#FN1]]
+; CHECK-NEXT: OpFunctionParameter %[[#I32]]
 ; CHECK-NEXT: OpFunctionEnd
 
 
@@ -32,22 +34,22 @@
   ret i32 %bar
 }
 
-; CHECK:      [[GOO]] = OpFunction [[I32]] None [[FN3]]
-; CHECK-NEXT: [[A:%.+]] = OpFunctionParameter [[I32]]
-; CHECK-NEXT: [[B:%.+]] = OpFunctionParameter [[I16]]
-; CHECK-NEXT: [[C:%.+]] = OpFunctionParameter [[I64]]
-; CHECK:      [[AGG1:%.+]] = OpCompositeInsert [[PAIR]] [[A]] [[UNDEF]] 0
-; CHECK:      [[AGG2:%.+]] = OpCompositeInsert [[PAIR]] [[B]] [[AGG1]] 1
-; CHECK:      [[RET:%.+]] = OpFunctionCall [[I32]] [[FOO]] [[AGG2]] [[C]]
-; CHECK:      OpReturnValue [[RET]]
+; CHECK:      %[[#GOO]] = OpFunction %[[#I32]] None %[[#FN3]]
+; CHECK-NEXT: %[[#A:]] = OpFunctionParameter %[[#I32]]
+; CHECK-NEXT: %[[#B:]] = OpFunctionParameter %[[#I16]]
+; CHECK-NEXT: %[[#C:]] = OpFunctionParameter %[[#I64]]
+; CHECK:      %[[#AGG1:]] = OpCompositeInsert %[[#PAIR]] %[[#A]] %[[#COMPOSITE]] 0
+; CHECK:      %[[#AGG2:]] = OpCompositeInsert %[[#PAIR]] %[[#B]] %[[#AGG1]] 1
+; CHECK:      %[[#RET:]] = OpFunctionCall %[[#I32]] %[[#FOO]] %[[#AGG2]] %[[#C]]
+; CHECK:      OpReturnValue %[[#RET]]
 ; CHECK:      OpFunctionEnd
 
-; CHECK:      [[FOO]] = OpFunction [[I32]] None [[FN2]]
-; CHECK-NEXT: [[IN:%.+]] = OpFunctionParameter [[PAIR]]
-; CHECK-NEXT: OpFunctionParameter [[I64]]
-; CHECK:      [[FIRST:%.+]] = OpCompositeExtract [[I32]] [[IN]] 0
-; CHECK:      [[BAR:%.+]] = OpFunctionCall [[I32]] [[FUN]] [[FIRST]]
-; CHECK:      OpReturnValue [[BAR]]
+; CHECK:      %[[#FOO]] = OpFunction %[[#I32]] None %[[#FN2]]
+; CHECK-NEXT: %[[#IN:]] = OpFunctionParameter %[[#PAIR]]
+; CHECK-NEXT: OpFunctionParameter %[[#I64]]
+; CHECK:      %[[#FIRST:]] = OpCompositeExtract %[[#I32]] %[[#IN]] 0
+; CHECK:      %[[#BAR:]] = OpFunctionCall %[[#I32]] %[[#FUN]] %[[#FIRST]]
+; CHECK:      OpReturnValue %[[#BAR]]
 ; CHECK:      OpFunctionEnd
 
 define i32 @goo(i32 %a, i16 %b, i64 %c) {
Index: llvm/test/CodeGen/SPIRV/instructions/nested-composites.ll
===================================================================
--- llvm/test/CodeGen/SPIRV/instructions/nested-composites.ll
+++ llvm/test/CodeGen/SPIRV/instructions/nested-composites.ll
@@ -1,23 +1,25 @@
 ; RUN: llc -O0 -mtriple=spirv32-unknown-unknown %s -o - | FileCheck %s
 
-; CHECK-DAG: OpName [[FOOBAR:%.+]] "foobar"
-; CHECK-DAG: OpName [[PRODUCER:%.+]] "producer"
-; CHECK-DAG: OpName [[CONSUMER:%.+]] "consumer"
+; CHECK-DAG: OpName %[[#FOOBAR:]] "foobar"
+; CHECK-DAG: OpName %[[#PRODUCER:]] "producer"
+; CHECK-DAG: OpName %[[#CONSUMER:]] "consumer"
 
 ; CHECK-NOT: DAG-FENCE
 
 %ty1 = type {i16, i32}
 %ty2 = type {%ty1, i64}
 
-; CHECK-DAG: [[I16:%.+]] = OpTypeInt 16
-; CHECK-DAG: [[I32:%.+]] = OpTypeInt 32
-; CHECK-DAG: [[I64:%.+]] = OpTypeInt 64
-; CHECK-DAG: [[TY1:%.+]] = OpTypeStruct [[I16]] [[I32]]
-; CHECK-DAG: [[TY2:%.+]] = OpTypeStruct [[TY1]] [[I64]]
-; CHECK-DAG: [[UNDEF_I16:%.+]] = OpUndef [[I16]]
-; CHECK-DAG: [[UNDEF_I64:%.+]] = OpUndef [[I64]]
-; CHECK-DAG: [[UNDEF_TY2:%.+]] = OpUndef [[TY2]]
-; CHECK-DAG: [[CST_42:%.+]] = OpConstant [[I32]] 42
+; CHECK-DAG: %[[#I16:]] = OpTypeInt 16
+; CHECK-DAG: %[[#I32:]] = OpTypeInt 32
+; CHECK-DAG: %[[#I64:]] = OpTypeInt 64
+; CHECK-DAG: %[[#TY1:]] = OpTypeStruct %[[#I16]] %[[#I32]]
+; CHECK-DAG: %[[#TY2:]] = OpTypeStruct %[[#TY1]] %[[#I64]]
+; CHECK-DAG: %[[#UNDEF_I16:]] = OpUndef %[[#I16]]
+; CHECK-DAG: %[[#UNDEF_I64:]] = OpUndef %[[#I64]]
+; CHECK-DAG: %[[#UNDEF_I32:]] = OpUndef %[[#I32]]
+; CHECK-DAG: %[[#CST_42:]] = OpConstant %[[#I32]] 42
+; CHECK-DAG: %[[#COMPOSITE1:]] = OpConstantComposite %[[#TY1]] %[[#UNDEF_I16]] %[[#UNDEF_I32]]
+; CHECK-DAG: %[[#COMPOSITE2:]] = OpConstantComposite %[[#TY2]] %[[#COMPOSITE1]] %[[#UNDEF_I64]]
 
 ; CHECK-NOT: DAG-FENCE
 
@@ -27,10 +29,10 @@
   ret i32 %ret
 }
 
-; CHECK: [[FOOBAR]] = OpFunction
-; CHECK: [[AGG:%.+]] = OpFunctionCall [[TY2]] [[PRODUCER]] [[UNDEF_I16]] [[CST_42]] [[UNDEF_I64]]
-; CHECK: [[RET:%.+]] = OpFunctionCall [[I32]] [[CONSUMER]] [[AGG]]
-; CHECK: OpReturnValue [[RET]]
+; CHECK: %[[#FOOBAR]] = OpFunction
+; CHECK: %[[#AGG:]] = OpFunctionCall %[[#TY2]] %[[#PRODUCER]] %[[#UNDEF_I16]] %[[#CST_42]] %[[#UNDEF_I64]]
+; CHECK: %[[#RET:]] = OpFunctionCall %[[#I32]] %[[#CONSUMER]] %[[#AGG]]
+; CHECK: OpReturnValue %[[#RET]]
 ; CHECK: OpFunctionEnd
 
 
@@ -41,14 +43,14 @@
   ret %ty2 %agg3
 }
 
-; CHECK: [[PRODUCER]] = OpFunction
-; CHECK: [[A:%.+]] = OpFunctionParameter [[I16]]
-; CHECK: [[B:%.+]] = OpFunctionParameter [[I32]]
-; CHECK: [[C:%.+]] = OpFunctionParameter [[I64]]
-; CHECK: [[AGG1:%.+]] = OpCompositeInsert [[TY2]] [[A]] [[UNDEF_TY2]] 0 0
-; CHECK: [[AGG2:%.+]] = OpCompositeInsert [[TY2]] [[B]] [[AGG1]] 0 1
-; CHECK: [[AGG3:%.+]] = OpCompositeInsert [[TY2]] [[C]] [[AGG2]] 1
-; CHECK: OpReturnValue [[AGG3]]
+; CHECK: %[[#PRODUCER]] = OpFunction
+; CHECK: %[[#A:]] = OpFunctionParameter %[[#I16]]
+; CHECK: %[[#B:]] = OpFunctionParameter %[[#I32]]
+; CHECK: %[[#C:]] = OpFunctionParameter %[[#I64]]
+; CHECK: %[[#AGG1:]] = OpCompositeInsert %[[#TY2]] %[[#A]] %[[#COMPOSITE2]] 0 0
+; CHECK: %[[#AGG2:]] = OpCompositeInsert %[[#TY2]] %[[#B]] %[[#AGG1]] 0 1
+; CHECK: %[[#AGG3:]] = OpCompositeInsert %[[#TY2]] %[[#C]] %[[#AGG2]] 1
+; CHECK: OpReturnValue %[[#AGG3]]
 ; CHECK: OpFunctionEnd
 
 
@@ -57,8 +59,8 @@
   ret i32 %ret
 }
 
-; CHECK: [[CONSUMER]] = OpFunction
-; CHECK: [[AGG:%.+]] = OpFunctionParameter [[TY2]]
-; CHECK: [[RET:%.+]] = OpCompositeExtract [[I32]] [[AGG]] 0 1
-; CHECK: OpReturnValue [[RET]]
+; CHECK: %[[#CONSUMER]] = OpFunction
+; CHECK: %[[#AGG:]] = OpFunctionParameter %[[#TY2]]
+; CHECK: %[[#RET:]] = OpCompositeExtract %[[#I32]] %[[#AGG]] 0 1
+; CHECK: OpReturnValue %[[#RET]]
 ; CHECK: OpFunctionEnd
Index: llvm/test/CodeGen/SPIRV/instructions/undef-composite-store.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/SPIRV/instructions/undef-composite-store.ll
@@ -0,0 +1,20 @@
+; RUN: llc -O0 -mtriple=spirv32-unknown-unknown %s -o - | FileCheck %s
+
+; CHECK-DAG: %[[#I32:]] = OpTypeInt 32
+; CHECK-DAG: %[[#I16:]] = OpTypeInt 16
+; CHECK-DAG: %[[#STRUCT:]] = OpTypeStruct %[[#I32]] %[[#I16]]
+; CHECK-DAG: %[[#UNDEF_I32:]] = OpUndef %[[#I32]]
+; CHECK-DAG: %[[#UNDEF_I16:]] = OpUndef %[[#I16]]
+; CHECK-DAG: %[[#COMPOSITE:]] = OpConstantComposite %[[#STRUCT]] %[[#UNDEF_I32]] %[[#UNDEF_I16]]
+
+; CHECK: %[[#]] = OpFunction %[[#]] None %[[#]]
+; CHECK-NEXT: %[[#PTR:]] = OpFunctionParameter %[[#]]
+; CHECK-NEXT: %[[#]] = OpLabel
+; CHECK-NEXT: OpStore %[[#PTR]] %[[#COMPOSITE]] Aligned 4
+; CHECK-NEXT: OpReturn
+; CHECK-NEXT: OpFunctionEnd
+
+define void @foo(ptr %ptr) {
+  store { i32, i16 } undef, ptr %ptr
+  ret void
+}