[SYCL] Cast to correct address space when a function object is passed

clang/include/clang/Driver/Options.td

@@ -5524,7 +5524,11 @@ def fsycl_int_header_EQ : Joined<["-"], "fsycl-int-header=">,
 def fsycl_std_layout_kernel_params: Flag<["-"], "fsycl-std-layout-kernel-params">,
   HelpText<"Enable standard layout requirement for SYCL kernel parameters.">,
   MarshallingInfoFlag<LangOpts<"SYCLStdLayoutKernelParams">>;
-defm sycl_allow_func_ptr: OptInFFlag<"sycl-allow-func-ptr", "Allow", "Disallow", " function pointers in SYCL device.", [CC1Option,CoreOption], LangOpts<"SYCLAllowFuncPtr">>;
+defm sycl_allow_func_ptr: BoolFOption<"sycl-allow-func-ptr",
+  LangOpts<"SYCLAllowFuncPtr">, DefaultFalse,
+  PosFlag<SetTrue, [], "Allow">,
+  NegFlag<SetFalse, [], "Disallow">,
+  BothFlags<[CC1Option, CoreOption], " function pointers in SYCL device.">>;
 def fenable_sycl_dae : Flag<["-"], "fenable-sycl-dae">,
   HelpText<"Enable Dead Argument Elimination in SPIR kernels">,
   MarshallingInfoFlag<LangOpts<"EnableDAEInSpirKernels">>;

clang/lib/CodeGen/CGCall.cpp

@@ -4774,9 +4774,14 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
         // If the argument doesn't match, perform a bitcast to coerce it.  This
         // can happen due to trivial type mismatches.
         if (FirstIRArg < IRFuncTy->getNumParams() &&
-            V->getType() != IRFuncTy->getParamType(FirstIRArg))
-          V = Builder.CreateBitCast(V, IRFuncTy->getParamType(FirstIRArg));
-
+            V->getType() != IRFuncTy->getParamType(FirstIRArg)) {
+          if (V->getType()->getPointerAddressSpace() !=
+              IRFuncTy->getParamType(FirstIRArg)->getPointerAddressSpace())
+            V = Builder.CreateAddrSpaceCast(V,
+                                            IRFuncTy->getParamType(FirstIRArg));
+          else
+            V = Builder.CreateBitCast(V, IRFuncTy->getParamType(FirstIRArg));
+        }
         IRCallArgs[FirstIRArg] = V;
         break;
       }

clang/test/CodeGenSYCL/invoke-function-addrspace.cpp

@@ -0,0 +1,31 @@
+// RUN: %clang_cc1 -sycl-std=2020 -fsycl-is-device -fsycl-allow-func-ptr -internal-isystem %S/Inputs -disable-llvm-passes -triple spir64-unknown-unknown-sycldevice -emit-llvm -o - %s | FileCheck %s
+
+// Test that the type of function object invoked from the kernel has
+// the right address space.
+
+#include "sycl.hpp"
+
+using namespace cl::sycl;
+queue q;
+
+// CHECK: define linkonce_odr spir_func i32 @{{.*}}invoke_function{{.*}}(i32 () addrspace(4)* %f)
+template <typename Callable>
+auto invoke_function(Callable &&f) {
+  // CHECK: %f.addr = alloca i32 () addrspace(4)*, align 8
+  // CHECK: %f.addr.ascast = addrspacecast i32 () addrspace(4)** %f.addr to i32 () addrspace(4)* addrspace(4)*
+  // CHECK: store i32 () addrspace(4)* %f, i32 () addrspace(4)* addrspace(4)* %f.addr.ascast, align 8
+  // CHECK: %0 = load i32 () addrspace(4)*, i32 () addrspace(4)* addrspace(4)* %f.addr.ascast, align 8
+  // CHECK: %call = call spir_func addrspace(4) i32 %0()
+  return f();
+}
+
+// CHECK: define dso_local spir_func i32 @{{.*}}bar10{{.*}}()
+int bar10() { return 10; }
+
+int main() {
+  kernel_single_task<class KernelName>(
+      [=]() {
+        invoke_function(bar10);
+      });
+  return 0;
+}