AMDGPU: Fix assert when erroring on a call

[arsenm]

Summary

For some reason an assert is now hit when a valid chain is not returned, so return the entry chain.

[arsenm]

Fix another assert. Test erroring multiple times in the same module

[• tstellarAMD]

LGTM.

[arsenm]

r269948

lib/Target/AMDGPU/AMDGPUISelLowering.cpp

SDValue AMDGPUTargetLowering::LowerCall(CallLoweringInfo &CLI,
   if (const ExternalSymbolSDNode *G = dyn_cast<ExternalSymbolSDNode>(Callee))
     FuncName = G->getSymbol();
   else if (const GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
     FuncName = G->getGlobal()->getName();
 
   DiagnosticInfoUnsupported NoCalls(
       Fn, "unsupported call to function " + FuncName, CLI.DL.getDebugLoc());
   DAG.getContext()->diagnose(NoCalls);
-  return SDValue();
+
+  for (unsigned I = 0, E = CLI.Ins.size(); I != E; ++I)
+    InVals.push_back(DAG.getUNDEF(CLI.Ins[I].VT));
+
+  return DAG.getEntryNode();
 }
 
 SDValue AMDGPUTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
                                                       SelectionDAG &DAG) const {
   const Function &Fn = *DAG.getMachineFunction().getFunction();
 
   DiagnosticInfoUnsupported NoDynamicAlloca(Fn, "unsupported dynamic alloca",
                                             SDLoc(Op).getDebugLoc());

test/CodeGen/AMDGPU/call.ll

-; RUN: not llc -march=amdgcn -mcpu=SI -verify-machineinstrs -exit-on-error < %s 2>&1 | FileCheck %s
-; RUN: not llc -march=amdgcn -mcpu=tonga -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 -verify-machineinstrs < %s 2>&1 | FileCheck %s
+; RUN: not llc -march=amdgcn -mcpu=tonga -verify-machineinstrs < %s 2>&1 | FileCheck %s
+; RUN: not llc -march=r600 -mcpu=cypress < %s 2>&1 | FileCheck %s
 
 ; CHECK: in function test_call_external{{.*}}: unsupported call to function external_function
+; CHECK: in function test_call{{.*}}: unsupported call to function defined_function
+; CHECK: in function test_tail_call{{.*}}: unsupported call to function defined_function
 
 
 declare i32 @external_function(i32) nounwind
 
 define void @test_call_external(i32 addrspace(1)* %out, i32 addrspace(1)* %in) {
   %b_ptr = getelementptr i32, i32 addrspace(1)* %in, i32 1
   %a = load i32, i32 addrspace(1)* %in
   %b = load i32, i32 addrspace(1)* %b_ptr
define void @test_call(i32 addrspace(1)* %out, i32 addrspace(1)* %in) {
   %b_ptr = getelementptr i32, i32 addrspace(1)* %in, i32 1
   %a = load i32, i32 addrspace(1)* %in
   %b = load i32, i32 addrspace(1)* %b_ptr
   %c = call i32 @defined_function(i32 %b) nounwind
   %result = add i32 %a, %c
   store i32 %result, i32 addrspace(1)* %out
   ret void
 }
+
+define void @test_tail_call(i32 addrspace(1)* %out, i32 addrspace(1)* %in) {
+  %b_ptr = getelementptr i32, i32 addrspace(1)* %in, i32 1
+  %a = load i32, i32 addrspace(1)* %in
+  %b = load i32, i32 addrspace(1)* %b_ptr
+  %c = tail call i32 @defined_function(i32 %b) nounwind
+  %result = add i32 %a, %c
+  store i32 %result, i32 addrspace(1)* %out
+  ret void
+}