[CIR][HIP] Use CUDA attributes for HIP global functions (#1333)

Author: koparasy

clang/lib/CIR/CodeGen/CIRGenModule.cpp

@@ -2357,8 +2357,9 @@ cir::FuncOp CIRGenModule::GetAddrOfFunction(clang::GlobalDecl GD, mlir::Type Ty,
   // As __global__ functions (kernels) always reside on device,
   // when we access them from host, we must refer to the kernel handle.
   // For CUDA, it's just the device stub. For HIP, it's something different.
-  if (langOpts.CUDA && !langOpts.CUDAIsDevice && langOpts.HIP &&
-      cast<FunctionDecl>(GD.getDecl())->hasAttr<CUDAGlobalAttr>()) {
+  if ((langOpts.CUDA || langOpts.HIP) && !langOpts.CUDAIsDevice &&
+      cast<FunctionDecl>(GD.getDecl())->hasAttr<CUDAGlobalAttr>() &&
+      cast<FunctionDecl>(GD.getDecl())->isThisDeclarationADefinition()) {
     llvm_unreachable("NYI");
   }
 

clang/test/CIR/CodeGen/HIP/simple-device.cpp

@@ -1,16 +1,31 @@
 #include "../Inputs/cuda.h"
 
-// RUN: %clang_cc1 -triple=amdgcn-amd-amdhsa -x hip -fclangir \
-// RUN:            -emit-cir %s -o %t.cir
-// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir \
+// RUN:            -x hip -emit-cir %s -o %t.cir
+// RUN: FileCheck --check-prefix=CIR-HOST --input-file=%t.cir %s
 
+// RUN: %clang_cc1 -triple=amdgcn-amd-amdhsa -x hip \
+// RUN:            -fcuda-is-device -emit-cir %s -o %t.cir
+// RUN: FileCheck --check-prefix=CIR-DEVICE --input-file=%t.cir %s
+
+// Attribute for global_fn
+// CIR-HOST: [[Kernel:#[a-zA-Z_0-9]+]] = {{.*}}#cir.cuda_kernel_name<_Z9global_fnv>{{.*}}
 
-// This should emit as a normal C++ function.
 __host__ void host_fn(int *a, int *b, int *c) {}
+// CIR-HOST: cir.func @_Z7host_fnPiS_S_
+// CIR-DEVICE-NOT: cir.func @_Z7host_fnPiS_S_
 
-// CIR: cir.func @_Z7host_fnPiS_S_
+__device__ void device_fn(int *a, double b, float c) {}
+// CIR-HOST-NOT: cir.func @_Z9device_fnPidf
+// CIR-DEVICE: cir.func @_Z9device_fnPidf
 
-// This shouldn't emit.
-__device__ void device_fn(int* a, double b, float c) {}
+#ifdef __AMDGPU__
+__global__ void global_fn() {}
+#else
+__global__ void global_fn();
+#endif
+// CIR-HOST: @_Z24__device_stub__global_fnv(){{.*}}extra([[Kernel]])
+// CIR-DEVICE: @_Z9global_fnv
 
-// CHECK-NOT: cir.func @_Z9device_fnPidf
+// Make sure `global_fn` indeed gets emitted
+__host__ void x() { auto v = global_fn; }