[SYCL] Fix AMD architecture flag (#425)

The flag is no longer passed through mcpu

Author: npmiller

SYCL/README.md

@@ -111,7 +111,7 @@ Defaults to AMD if no value is given. Supported values are:
  - **AMD**    - for ROCm to target AMD GPUs
  - **NVIDIA** - for ROCm to target NVIDIA GPUs
 
- ***MCPU*** Flag must be set for when using ROCm triple. 
+ ***AMD_ARCH*** Flag must be set for when using ROCm triple.
  For example it may be set to "gfx906".
 
 

SYCL/lit.cfg.py

@@ -184,13 +184,13 @@
     lit_config.error("Unknown ROCm platform '" + config.rocm_platform + "' supported platforms are " + ', '.join(supported_rocm_platforms))
 
 if config.sycl_be == "rocm" and config.rocm_platform == "AMD":
-    mcpu_flag = '-mcpu=' + config.mcpu
+    arch_flag = '-Xsycl-target-backend=amdgcn-amd-amdhsa-sycldevice --offload-arch=' + config.amd_arch
 else:
-    mcpu_flag = ""
+    arch_flag = ""
 
 # extra_include points to sycl/sycl.hpp location to workaround compiler
 # versions which supports only CL/sycl.hpp
-config.substitutions.append( ('%clangxx', ' '+ config.dpcpp_compiler + ' ' + config.cxx_flags + ' ' + mcpu_flag + ( "/I" if cl_options else "-I") + config.extra_include ) )
+config.substitutions.append( ('%clangxx', ' '+ config.dpcpp_compiler + ' ' + config.cxx_flags + ' ' + arch_flag + ' ' + ( "/I" if cl_options else "-I") + config.extra_include ) )
 config.substitutions.append( ('%clang', ' ' + config.dpcpp_compiler + ' ' + config.c_flags + ( "/I" if cl_options else "-I") + config.extra_include ) )
 config.substitutions.append( ('%threads_lib', config.sycl_threads_lib) )
 

SYCL/lit.site.cfg.py.in

@@ -23,7 +23,7 @@ config.opencl_include_dir = os.path.join(config.sycl_include, 'sycl')
 config.target_devices = lit_config.params.get("target_devices", "@SYCL_TARGET_DEVICES@")
 config.sycl_be = lit_config.params.get("sycl_be", "@SYCL_BE@")
 config.rocm_platform = "@ROCM_PLATFORM@"
-config.mcpu = "@MCPU@"
+config.amd_arch = "@AMD_ARCH@"
 config.sycl_threads_lib = '@SYCL_THREADS_LIB@'
 config.extra_environment = lit_config.params.get("extra_environment", "@LIT_EXTRA_ENVIRONMENT@")
 config.cxx_flags = "@CMAKE_CXX_FLAGS@"