[SYCL] Cast to correct address space when a function object is passed (#3303)

When a function object is passed as an argument to a call,
type mismatches may be address space mismatches and these
cannot be bitcast away.  Check if it is an address space
mismatch and if so, use the appropriate address space cast.

Signed-off-by: Premanand M Rao <[email protected]>

Author: premanandrao

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;
+}