diff --git a/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp b/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
--- a/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
+++ b/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
@@ -2617,7 +2617,14 @@
   std::string ParamSym;
   raw_string_ostream ParamStr(ParamSym);
 
-  ParamStr << DAG.getMachineFunction().getName();
+  if (StringRef FnName = DAG.getMachineFunction().getName(); !FnName.empty()) {
+    ParamStr << FnName;
+  } else {
+    SmallString<128> NameBuf;
+    getTargetMachine().getObjFileLowering()->getNameWithPrefix(
+        NameBuf, &DAG.getMachineFunction().getFunction(), getTargetMachine());
+    ParamStr << NameBuf;
+  }
 
   if (idx < 0)
     ParamStr << "_vararg";
diff --git a/llvm/test/CodeGen/NVPTX/anonymous-fn-param.ll b/llvm/test/CodeGen/NVPTX/anonymous-fn-param.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/NVPTX/anonymous-fn-param.ll
@@ -0,0 +1,22 @@
+; RUN: llc < %s -march=nvptx64 -mcpu=sm_20 | FileCheck %s
+; RUN: %if ptxas %{ llc < %s -march=nvptx64 -mcpu=sm_20 | %ptxas-verify %}
+
+; CHECK:      .func (.param .b32 func_retval0) __unnamed_1(
+; CHECK-NEXT: .param .b32 __unnamed_1_param_0
+; CHECK:      ld.param.u32 {{%r[0-9]+}}, [__unnamed_1_param_0];
+
+; CHECK:      .func (.param .b32 func_retval0) __unnamed_2(
+; CHECK-NEXT: .param .b32 __unnamed_2_param_0
+; CHECK:      ld.param.u32 {{%r[0-9]+}}, [__unnamed_2_param_0];
+
+define internal i32 @0(i32 %a) {
+entry:
+  %r = add i32 %a, 1
+  ret i32 %r
+}
+
+define internal i32 @1(i32 %a) {
+entry:
+  %r = add i32 %a, 1
+  ret i32 %r
+}