diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -9979,15 +9979,30 @@
 // SPIR ABI Implementation
 //===----------------------------------------------------------------------===//
 
+namespace {
+class SPIRABIInfo : public DefaultABIInfo {
+public:
+  SPIRABIInfo(CodeGenTypes &CGT) : DefaultABIInfo(CGT) {
+    setCCs();
+  }
+
+private:
+  void setCCs();
+};
+} // end anonymous namespace
 namespace {
 class SPIRTargetCodeGenInfo : public TargetCodeGenInfo {
 public:
   SPIRTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT)
-      : TargetCodeGenInfo(std::make_unique<DefaultABIInfo>(CGT)) {}
+      : TargetCodeGenInfo(std::make_unique<SPIRABIInfo>(CGT)) {}
   unsigned getOpenCLKernelCallingConv() const override;
 };
 
 } // End anonymous namespace.
+void SPIRABIInfo::setCCs() {
+  assert(getRuntimeCC() == llvm::CallingConv::C);
+  RuntimeCC = llvm::CallingConv::SPIR_FUNC;
+}
 
 namespace clang {
 namespace CodeGen {
diff --git a/clang/test/CodeGenOpenCLCXX/atexit.cl b/clang/test/CodeGenOpenCLCXX/atexit.cl
--- a/clang/test/CodeGenOpenCLCXX/atexit.cl
+++ b/clang/test/CodeGenOpenCLCXX/atexit.cl
@@ -5,7 +5,7 @@
 };
 S s;
 
-//CHECK-LABEL: define internal void @__cxx_global_var_init()
-//CHECK: call i32 @__cxa_atexit(void (i8*)* bitcast (void (%struct.S addrspace(4)*)* @_ZNU3AS41SD1Ev to void (i8*)*), i8* null, i8 addrspace(1)* @__dso_handle)
+//CHECK-LABEL: define internal spir_func void @__cxx_global_var_init()
+//CHECK: call spir_func i32 @__cxa_atexit(void (i8*)* bitcast (void (%struct.S addrspace(4)*)* @_ZNU3AS41SD1Ev to void (i8*)*), i8* null, i8 addrspace(1)* @__dso_handle)
 
-//CHECK: declare i32 @__cxa_atexit(void (i8*)*, i8*, i8 addrspace(1)*)
+//CHECK: declare spir_func i32 @__cxa_atexit(void (i8*)*, i8*, i8 addrspace(1)*)