[OpenCL] AMDGPU: add support of cl_khr_subgroups

[ashi1]

Summary

Adding extension cl_khr_subgroups to clang's OpenCL Extensions and initiated inside AMDGPU Target. Similar to https://reviews.llvm.org/D22637

[yaxunl]

LGTM. Thanks!

Better update the title to be [OpenCL] AMDGPU: add support of cl_khr_subgroups since cl_khr_subgroups is already in clang.

cfe/trunk/lib/Basic/Targets.cpp

if (GPU >= GK_EVERGREEN) {
       Opts.cl_khr_local_int32_base_atomics = 1;
       Opts.cl_khr_local_int32_extended_atomics = 1;
     }
     if (GPU >= GK_SOUTHERN_ISLANDS) {
       Opts.cl_khr_fp16 = 1;
       Opts.cl_khr_int64_base_atomics = 1;
       Opts.cl_khr_int64_extended_atomics = 1;
       Opts.cl_khr_mipmap_image = 1;
+      Opts.cl_khr_subgroups = 1;
       Opts.cl_khr_3d_image_writes = 1;
       Opts.cl_amd_media_ops = 1;
       Opts.cl_amd_media_ops2 = 1;
     }
   }
 
   LangAS::ID getOpenCLImageAddrSpace() const override {
     return LangAS::opencl_constant;

cfe/trunk/test/Misc/amdgcn.languageOptsOpenCL.cl

 #pragma OPENCL EXTENSION cl_khr_mipmap_image: enable
 
 #ifdef cl_khr_srgb_image_writes
 #error "Incorrect cl_khr_srgb_image_writes define"
 #endif
 #pragma OPENCL EXTENSION cl_khr_srgb_image_writes: enable
 // expected-warning@-1{{unsupported OpenCL extension 'cl_khr_srgb_image_writes' - ignoring}}
 
+#if (__OPENCL_C_VERSION__ >= 200)
+#ifndef cl_khr_subgroups
+#error "Missing cl_khr_subgroups define"
+#endif
+#else
 #ifdef cl_khr_subgroups
 #error "Incorrect cl_khr_subgroups define"
 #endif
+// expected-warning@+2{{unsupported OpenCL extension 'cl_khr_subgroups' - ignoring}}
+#endif
 #pragma OPENCL EXTENSION cl_khr_subgroups: enable
-// expected-warning@-1{{unsupported OpenCL extension 'cl_khr_subgroups' - ignoring}}
 
 #ifdef cl_khr_terminate_context
 #error "Incorrect cl_khr_terminate_context define"
 #endif
 #pragma OPENCL EXTENSION cl_khr_terminate_context: enable
 // expected-warning@-1{{unsupported OpenCL extension 'cl_khr_terminate_context' - ignoring}}
 
 #ifndef cl_amd_media_ops

cfe/trunk/test/SemaOpenCL/extension-version.cl

 #endif
 #pragma OPENCL EXTENSION cl_khr_srgb_image_writes: enable
 
 #if (__OPENCL_C_VERSION__ >= 200)
 #ifndef cl_khr_subgroups
 #error "Missing cl_khr_subgroups define"
 #endif
 #else
+#ifdef cl_khr_subgroups
+#error "Incorrect cl_khr_subgroups define"
+#endif
 // expected-warning@+2{{unsupported OpenCL extension 'cl_khr_subgroups' - ignoring}}
 #endif
 #pragma OPENCL EXTENSION cl_khr_subgroups: enable
 
 #if (__OPENCL_C_VERSION__ >= 200)
 #ifndef cl_khr_terminate_context
 #error "Missing cl_khr_terminate_context define"
 #endif