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 +9979,28 @@
 // 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/CodeGen/complex-math.c b/clang/test/CodeGen/complex-math.c
--- a/clang/test/CodeGen/complex-math.c
+++ b/clang/test/CodeGen/complex-math.c
@@ -6,6 +6,7 @@
 // RUN: %clang_cc1 %s -O0 -fno-experimental-new-pass-manager -emit-llvm -triple armv7-none-linux-gnueabihf -o - | FileCheck %s --check-prefix=ARMHF
 // RUN: %clang_cc1 %s -O0 -fno-experimental-new-pass-manager -emit-llvm -triple thumbv7k-apple-watchos2.0 -o - -target-abi aapcs16 | FileCheck %s --check-prefix=ARM7K
 // RUN: %clang_cc1 %s -O0 -fno-experimental-new-pass-manager -emit-llvm -triple aarch64-unknown-unknown -ffast-math -ffp-contract=fast -o - | FileCheck %s --check-prefix=AARCH64-FASTMATH
+// RUN: %clang_cc1 %s -O0 -fno-experimental-new-pass-manager -emit-llvm -triple spir -o - | FileCheck %s --check-prefix=SPIR
 
 float _Complex add_float_rr(float a, float b) {
   // X86-LABEL: @add_float_rr(
@@ -107,6 +108,7 @@
   // X86: fcmp uno float %[[RI]]
   // X86: call {{.*}} @__mulsc3(
   // X86: ret
+  // SPIR: call spir_func {{.*}} @__mulsc3(
   return a * b;
 }
 
@@ -131,6 +133,8 @@
   // X86: call {{.*}} @__divsc3(
   // X86: ret
 
+  // SPIR: call spir_func {{.*}} @__divsc3(
+
   // a / b = (A+iB) / (C+iD) = ((AC+BD)/(CC+DD)) + i((BC-AD)/(CC+DD))
   // AARCH64-FASTMATH-LABEL: @div_float_rc(float %a, [2 x float] %b.coerce)
   // A = a
@@ -158,6 +162,8 @@
   // X86: call {{.*}} @__divsc3(
   // X86: ret
 
+  // SPIR: call spir_func {{.*}} @__divsc3(
+
   // a / b = (A+iB) / (C+iD) = ((AC+BD)/(CC+DD)) + i((BC-AD)/(CC+DD))
   // AARCH64-FASTMATH-LABEL: @div_float_cc([2 x float] %a.coerce, [2 x float] %b.coerce)
   //
@@ -278,6 +284,8 @@
   // X86: fcmp uno double %[[RI]]
   // X86: call {{.*}} @__muldc3(
   // X86: ret
+
+  // SPIR: call spir_func {{.*}} @__muldc3(
   return a * b;
 }
 
@@ -302,6 +310,8 @@
   // X86: call {{.*}} @__divdc3(
   // X86: ret
 
+  // SPIR: call spir_func {{.*}} @__divdc3(
+
   // a / b = (A+iB) / (C+iD) = ((AC+BD)/(CC+DD)) + i((BC-AD)/(CC+DD))
   // AARCH64-FASTMATH-LABEL: @div_double_rc(double %a, [2 x double] %b.coerce)
   // A = a
@@ -329,6 +339,8 @@
   // X86: call {{.*}} @__divdc3(
   // X86: ret
 
+  // SPIR: call spir_func {{.*}} @__divdc3(
+
   // a / b = (A+iB) / (C+iD) = ((AC+BD)/(CC+DD)) + i((BC-AD)/(CC+DD))
   // AARCH64-FASTMATH-LABEL: @div_double_cc([2 x double] %a.coerce, [2 x double] %b.coerce)
   //
@@ -463,6 +475,7 @@
   // PPC: fcmp uno ppc_fp128 %[[RI]]
   // PPC: call {{.*}} @__multc3(
   // PPC: ret
+  // SPIR: call spir_func {{.*}} @__muldc3(
   return a * b;
 }
 
@@ -490,6 +503,7 @@
   // PPC-NOT: fdiv
   // PPC: call {{.*}} @__divtc3(
   // PPC: ret
+  // SPIR: call spir_func {{.*}} @__divdc3(
 
   // a / b = (A+iB) / (C+iD) = ((AC+BD)/(CC+DD)) + i((BC-AD)/(CC+DD))
   // AARCH64-FASTMATH-LABEL: @div_long_double_rc(fp128 %a, [2 x fp128] %b.coerce)
@@ -521,6 +535,7 @@
   // PPC-NOT: fdiv
   // PPC: call {{.*}} @__divtc3(
   // PPC: ret
+  // SPIR: call spir_func {{.*}} @__divdc3(
 
   // a / b = (A+iB) / (C+iD) = ((AC+BD)/(CC+DD)) + i((BC-AD)/(CC+DD))
   // AARCH64-FASTMATH-LABEL: @div_long_double_cc([2 x fp128] %a.coerce, [2 x fp128] %b.coerce)
@@ -603,6 +618,8 @@
   // ARM-LABEL: @foo(
   // ARM: call void @__muldc3
 
+  // SPIR: call spir_func void @__muldc3
+
   // ARMHF-LABEL: @foo(
   // ARMHF: call { double, double } @__muldc3
 
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)*)