[HIP] Mark kernels with uniform-work-group-size=true

Differential Revision: https://reviews.llvm.org/D76076

Author: yxsamliu

clang/lib/CodeGen/TargetInfo.cpp

@@ -8091,6 +8091,10 @@ void AMDGPUTargetCodeGenInfo::setTargetAttributes(
       (M.getTriple().getOS() == llvm::Triple::AMDHSA))
     F->addFnAttr("amdgpu-implicitarg-num-bytes", "56");
 
+  if (IsHIPKernel)
+    F->addFnAttr("uniform-work-group-size", "true");
+
+
   const auto *FlatWGS = FD->getAttr<AMDGPUFlatWorkGroupSizeAttr>();
   if (ReqdWGS || FlatWGS) {
     unsigned Min = 0;

clang/test/CodeGenCUDA/amdgpu-kernel-attrs.cu

@@ -39,7 +39,7 @@ __global__ void num_vgpr_64() {
 // NAMD-NOT: "amdgpu-num-vgpr"
 // NAMD-NOT: "amdgpu-num-sgpr"
 
-// DEFAULT-DAG: attributes [[FLAT_WORK_GROUP_SIZE_DEFAULT]] = {{.*}}"amdgpu-flat-work-group-size"="1,256"
+// DEFAULT-DAG: attributes [[FLAT_WORK_GROUP_SIZE_DEFAULT]] = {{.*}}"amdgpu-flat-work-group-size"="1,256"{{.*}}"uniform-work-group-size"="true"
 // MAX1024-DAG: attributes [[FLAT_WORK_GROUP_SIZE_DEFAULT]] = {{.*}}"amdgpu-flat-work-group-size"="1,1024"
 // CHECK-DAG: attributes [[FLAT_WORK_GROUP_SIZE_32_64]] = {{.*}}"amdgpu-flat-work-group-size"="32,64"
 // CHECK-DAG: attributes [[WAVES_PER_EU_2]] = {{.*}}"amdgpu-waves-per-eu"="2"