AMDGPU: Error more gracefully on libcalls

I think this is the only situation where the callsite
will have a null instruction.

llvm-svn: 339271

llvm/lib/Target/AMDGPU/SIISelLowering.cpp

@@ -2376,6 +2376,9 @@ SDValue SITargetLowering::LowerCall(CallLoweringInfo &CLI,
                               "unsupported call to variadic function ");
   }
 
+  if (!CLI.CS.getInstruction())
+    report_fatal_error("unsupported libcall legalization");
+
   if (!CLI.CS.getCalledFunction()) {
     return lowerUnhandledCall(CLI, InVals,
                               "unsupported indirect call to function ");

llvm/test/CodeGen/AMDGPU/div_i128.ll

@@ -0,0 +1,7 @@
+; RUN: not llc -mtriple=amdgcn-amd-amdhsa -verify-machineinstrs  %s 2>&1 | FileCheck %s
+
+; CHECK: LLVM ERROR: unsupported libcall legalization
+define i128 @v_sdiv_i128_vv(i128 %lhs, i128 %rhs) {
+  %shl = sdiv i128 %lhs, %rhs
+  ret i128 %shl
+}