Index: lib/Target/AMDGPU/AMDGPUISelLowering.cpp
===================================================================
--- lib/Target/AMDGPU/AMDGPUISelLowering.cpp
+++ lib/Target/AMDGPU/AMDGPUISelLowering.cpp
@@ -689,7 +689,8 @@
   DiagnosticInfoUnsupported NoDynamicAlloca(Fn, "unsupported dynamic alloca",
                                             SDLoc(Op).getDebugLoc());
   DAG.getContext()->diagnose(NoDynamicAlloca);
-  return SDValue();
+  auto Ops = {DAG.getIntPtrConstant(0, SDLoc()), Op.getOperand(0)};
+  return DAG.getMergeValues(Ops, SDLoc());
 }
 
 SDValue AMDGPUTargetLowering::LowerOperation(SDValue Op,
Index: lib/Target/AMDGPU/AMDGPUInstrInfo.cpp
===================================================================
--- lib/Target/AMDGPU/AMDGPUInstrInfo.cpp
+++ lib/Target/AMDGPU/AMDGPUInstrInfo.cpp
@@ -103,7 +103,9 @@
   const MachineFrameInfo *MFI = MF.getFrameInfo();
 
   // Variable sized objects are not supported
-  assert(!MFI->hasVarSizedObjects());
+  if (MFI->hasVarSizedObjects()) {
+    return -1;
+  }
 
   if (MFI->getNumObjects() == 0) {
     return -1;
Index: test/CodeGen/AMDGPU/dynamic_stackalloc.ll
===================================================================
--- test/CodeGen/AMDGPU/dynamic_stackalloc.ll
+++ test/CodeGen/AMDGPU/dynamic_stackalloc.ll
@@ -1,6 +1,6 @@
-; RUN: not llc -march=amdgcn -mcpu=tahiti -mattr=+promote-alloca -verify-machineinstrs -exit-on-error < %s 2>&1 | FileCheck %s
-; RUN: not llc -march=amdgcn -mcpu=tahiti -mattr=-promote-alloca -verify-machineinstrs -exit-on-error < %s 2>&1 | FileCheck %s
-; RUN: not llc -march=r600 -mcpu=cypress -exit-on-error < %s 2>&1 | FileCheck %s
+; RUN: not llc -march=amdgcn -mcpu=tahiti -mattr=+promote-alloca -verify-machineinstrs < %s 2>&1 | FileCheck %s
+; RUN: not llc -march=amdgcn -mcpu=tahiti -mattr=-promote-alloca -verify-machineinstrs < %s 2>&1 | FileCheck %s
+; RUN: not llc -march=r600 -mcpu=cypress < %s 2>&1 | FileCheck %s
 
 ; CHECK: in function test_dynamic_stackalloc{{.*}}: unsupported dynamic alloca