R600: Emit error instead of unreachable on function call

[arsenm]

r206904

lib/Target/R600/AMDGPUISelLowering.h

                               const SmallVectorImpl<SDValue> &OutVals,
                               SDLoc DL, SelectionDAG &DAG) const;
   virtual SDValue LowerCall(CallLoweringInfo &CLI,
-                            SmallVectorImpl<SDValue> &InVals) const {
-    CLI.Callee.dump();
-    llvm_unreachable("Undefined function");
-  }
+                            SmallVectorImpl<SDValue> &InVals) const;
 
   virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;
   virtual void ReplaceNodeResults(SDNode * N,

lib/Target/R600/AMDGPUISelLowering.cpp

 #include "llvm/CodeGen/SelectionDAG.h"
 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
 #include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DiagnosticInfo.h"
+#include "llvm/IR/DiagnosticPrinter.h"
 
 using namespace llvm;
+
+namespace {
+
+/// Diagnostic information for unimplemented or unsupported feature reporting.
+class DiagnosticInfoUnsupported : public DiagnosticInfo {
+private:
+  const Twine &Description;
+  const Function &Fn;
+
+  static int KindID;
+
+  static int getKindID() {
+    if (KindID == 0)
+      KindID = llvm::getNextAvailablePluginDiagnosticKind();
+    return KindID;
+  }
+
+public:
+  DiagnosticInfoUnsupported(const Function &Fn, const Twine &Desc,
+                          DiagnosticSeverity Severity = DS_Error)
+    : DiagnosticInfo(getKindID(), Severity),
+      Description(Desc),
+      Fn(Fn) { }
+
+  const Function &getFunction() const { return Fn; }
+  const Twine &getDescription() const { return Description; }
+
+  void print(DiagnosticPrinter &DP) const override {
+    DP << "unsupported " << getDescription() << " in " << Fn.getName();
+  }
+
+  static bool classof(const DiagnosticInfo *DI) {
+    return DI->getKind() == getKindID();
+  }
+};
+
+int DiagnosticInfoUnsupported::KindID = 0;
+}
+
+
 static bool allocateStack(unsigned ValNo, MVT ValVT, MVT LocVT,
                       CCValAssign::LocInfo LocInfo,
                       ISD::ArgFlagsTy ArgFlags, CCState &State) {

 // Target specific lowering
 //===---------------------------------------------------------------------===//
 
+SDValue AMDGPUTargetLowering::LowerCall(CallLoweringInfo &CLI,
+                                        SmallVectorImpl<SDValue> &InVals) const {
+  SDValue Callee = CLI.Callee;
+  SelectionDAG &DAG = CLI.DAG;
+
+  const Function &Fn = *DAG.getMachineFunction().getFunction();
+
+  StringRef FuncName("<unknown>");
+
+  if (const GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
+    FuncName = G->getGlobal()->getName();
+
+  DiagnosticInfoUnsupported NoCalls(Fn, "call to function " + FuncName);
+  DAG.getContext()->diagnose(NoCalls);
+  return SDValue();
+}
+
 SDValue AMDGPUTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG)
     const {
   switch (Op.getOpcode()) {

test/CodeGen/R600/call.ll

+; RUN: not llc -march=r600 -mcpu=SI < %s 2>&1 | FileCheck %s
+; RUN: not llc -march=r600 -mcpu=cypress < %s 2>&1 | FileCheck %s
+
+; CHECK: error: unsupported call to function defined_function in test_call
+
+
+declare i32 @external_function(i32) nounwind
+
+define i32 @defined_function(i32 %x) nounwind noinline {
+  %y = add i32 %x, 8
+  ret i32 %y
+}
+
+define void @test_call(i32 addrspace(1)* %out, i32 addrspace(1)* %in) {
+  %b_ptr = getelementptr i32 addrspace(1)* %in, i32 1
+  %a = load i32 addrspace(1)* %in
+  %b = load 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_call_external(i32 addrspace(1)* %out, i32 addrspace(1)* %in) {
+  %b_ptr = getelementptr i32 addrspace(1)* %in, i32 1
+  %a = load i32 addrspace(1)* %in
+  %b = load i32 addrspace(1)* %b_ptr
+  %c = call i32 @external_function(i32 %b) nounwind
+  %result = add i32 %a, %c
+  store i32 %result, i32 addrspace(1)* %out
+  ret void
+}
+