[SYCL-PTX] Libclc binding for SYCL device

SYCL uses a custom mangling scheme (mangles target address space 0).
This patch adds a "binding" layer (sycldevice-binding.cpp).
The binding layer is compiled in sycl device mode which allow to generate
the expected mangling when the target address space is 0.

Signed-off-by: Victor Lomuller <victor@codeplay.com>

libclc/CMakeLists.txt

@@ -227,8 +227,8 @@ foreach( t ${LIBCLC_TARGETS_TO_BUILD} )
 		LIB_DIR lib
 		DIRS ${dirs} ${DARCH} ${DARCH}-${OS} ${DARCH}-${VENDOR}-${OS}
 		DEPS convert-clc.cl )
-	set( libspirv_files )
-	libclc_configure_lib_source(libspirv_files
+	set( libspirv_files_base )
+	libclc_configure_lib_source(libspirv_files_base
 		LIB_DIR libspirv
 		DIRS ${dirs} ${DARCH} ${DARCH}-${OS} ${DARCH}-${VENDOR}-${OS}
 		DEPS convert-spirv.cl convert-core.cl)
@@ -244,6 +244,17 @@ foreach( t ${LIBCLC_TARGETS_TO_BUILD} )
 		endif()
 		message( "    DEVICE: ${d} ( ${${d}_aliases} )" )
 
+		# FIXME: this is a hack, remove once we can use sycldevice in the triple
+		#        without changing the language
+		# see issue: https://github.com/intel/llvm/issues/1814
+		set(libspirv_files ${libspirv_files_base})
+		if( ${ARCH} STREQUAL nvptx OR ${ARCH} STREQUAL nvptx64 )
+			add_libclc_sycl_binding(libspirv_files
+				TRIPLE ${t}
+				COMPILE_OPT ${mcpu}
+				FILES generic/libspirv/sycldevice-binding.cpp)
+		endif()
+
 		add_libclc_builtin_set(libspirv-${arch_suffix}
 			TRIPLE ${t}
 			TARGET_ENV libspirv

libclc/cmake/modules/AddLibclc.cmake

@@ -177,3 +177,55 @@ function(libclc_configure_lib_source OUT_LIST)
   set( ${OUT_LIST} ${rel_files} PARENT_SCOPE )
 
 endfunction(libclc_configure_lib_source OUT_LIST)
+
+# add_libclc_sycl_binding(arch_suffix
+#   TRIPLE string
+#     Triple used to compile
+#   FILES string ...
+#     List of file that should be built for this library
+#   COMPILE_OPT
+#     Compilation options
+#   )
+#
+# Build the sycl binding file for SYCLDEVICE.
+# The path to the generated object file are appended in OUT_LIST.
+#
+# The mangling for sycl device is not yet fully
+# compatible with standard mangling.
+# For various reason, we need a mangling specific
+# for the Default address space (mapping to generic in SYCL).
+# The Default address space is not accessible in CL mode,
+# so we build this file in sycl mode for mangling purposes.
+#
+# FIXME: all the files should be compiled with the sycldevice triple
+#        but this is not possible at the moment as this will trigger
+#        the SYCL mode which we don't want.
+#
+function(add_libclc_sycl_binding OUT_LIST)
+  cmake_parse_arguments(ARG
+    ""
+    "TRIPLE"
+    "FILES;COMPILE_OPT"
+    ${ARGN})
+
+	foreach( file ${ARG_FILES} )
+    file( TO_CMAKE_PATH ${LIBCLC_ROOT_DIR}/${file} SYCLDEVICE_BINDING )
+    if( EXISTS ${SYCLDEVICE_BINDING} )
+      set( SYCLDEVICE_BINDING_OUT ${CMAKE_CURRENT_BINARY_DIR}/sycldevice-binding-${ARG_TRIPLE}/sycldevice-binding.bc )
+      add_custom_command( OUTPUT ${SYCLDEVICE_BINDING_OUT}
+                         COMMAND ${LLVM_CLANG}
+                         -target ${ARG_TRIPLE}-sycldevice
+                         -fsycl
+                         -fsycl-device-only
+                         -Dcl_khr_fp64
+                         -I${LIBCLC_ROOT_DIR}/generic/include
+                         ${ARG_COMPILE_OPT}
+                         ${SYCLDEVICE_BINDING}
+                         -o ${SYCLDEVICE_BINDING_OUT}
+                     MAIN_DEPENDENCY ${SYCLDEVICE_BINDING}
+                     DEPENDS ${SYCLDEVICE_BINDING} ${LLVM_CLANG}
+                     VERBATIM )
+      set( ${OUT_LIST} "${${OUT_LIST}};${SYCLDEVICE_BINDING_OUT}" PARENT_SCOPE )
+    endif()
+  endforeach()
+endfunction(add_libclc_sycl_binding OUT_LIST)

libclc/generic/include/lp64_types.h

@@ -108,6 +108,10 @@ typedef half __clc_vec16_fp16_t __attribute__((ext_vector_type(16)));
 
 typedef __clc_int64_t __clc_size_t;
 
+#ifdef __SYCL_DEVICE_ONLY__
+typedef __ocl_event_t __clc_event_t;
+#else
 typedef event_t __clc_event_t;
+#endif
 
 #endif // CLC_LP64_TYPES