[SYCL] Implement required builtins for libdevice

Rather than have a dependency on SYCL headers in libdevice, implement the
required spirv builtins in the libdevice project.

Signed-off-by: Alexander Johnston <[email protected]>

Author: Alexander Johnston

libdevice/cmake/modules/SYCLLibdevice.cmake

@@ -6,8 +6,6 @@ endif()
 
 set(clang $<TARGET_FILE:clang>)
 
-set(sycl_spirv_headers ${LLVM_EXTERNAL_SYCL_SOURCE_DIR}/include/CL/__spirv)
-
 set(compile_opts
   # suppress an error about SYCL_EXTERNAL being used for
   # a function with a raw pointer parameter.
@@ -18,9 +16,6 @@ set(compile_opts
   # Force definition of CL_SYCL_LANGUAGE_VERSION, as long as
   # SYCL specific code is guarded by it.
   -sycl-std=2017
-  # We require the spirv_vars.hpp header from the sycl project
-  # for access to all the required spirv builtin vars
-  -I${sycl_spirv_headers}
   )
 
 if (WIN32)

libdevice/device.h

@@ -9,10 +9,6 @@
 #ifndef __LIBDEVICE_DEVICE_H__
 #define __LIBDEVICE_DEVICE_H__
 
-// We need the following header provided by the sycl project to ensure
-// definition of all spirv variables required by the wrapper libraries.
-#include "spirv_vars.hpp"
-
 #ifdef __cplusplus
 #define EXTERN_C extern "C"
 #else // __cplusplus

libdevice/spirv_vars.hpp

@@ -0,0 +1,102 @@
+//==---------- spirv_vars.hpp --- SPIRV variables -------------------------==//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// ===-------------------------------------------------------------------=== //
+
+#pragma once
+
+#include <cstddef>
+#include <cstdint>
+
+#ifdef __SYCL_DEVICE_ONLY__
+
+#ifdef __SYCL_NVPTX__
+
+SYCL_EXTERNAL size_t __spirv_GlobalInvocationId_x();
+SYCL_EXTERNAL size_t __spirv_GlobalInvocationId_y();
+SYCL_EXTERNAL size_t __spirv_GlobalInvocationId_z();
+
+SYCL_EXTERNAL size_t __spirv_LocalInvocationId_x();
+SYCL_EXTERNAL size_t __spirv_LocalInvocationId_y();
+SYCL_EXTERNAL size_t __spirv_LocalInvocationId_z();
+
+#else // __SYCL_NVPTX__
+
+typedef size_t size_t_vec __attribute__((ext_vector_type(3)));
+extern "C" const __attribute__((opencl_constant))
+size_t_vec __spirv_BuiltInGlobalInvocationId;
+extern "C" const __attribute__((opencl_constant))
+size_t_vec __spirv_BuiltInLocalInvocationId;
+
+SYCL_EXTERNAL inline size_t __spirv_GlobalInvocationId_x() {
+  return __spirv_BuiltInGlobalInvocationId.x;
+}
+SYCL_EXTERNAL inline size_t __spirv_GlobalInvocationId_y() {
+  return __spirv_BuiltInGlobalInvocationId.y;
+}
+SYCL_EXTERNAL inline size_t __spirv_GlobalInvocationId_z() {
+  return __spirv_BuiltInGlobalInvocationId.z;
+}
+
+SYCL_EXTERNAL inline size_t __spirv_LocalInvocationId_x() {
+  return __spirv_BuiltInLocalInvocationId.x;
+}
+SYCL_EXTERNAL inline size_t __spirv_LocalInvocationId_y() {
+  return __spirv_BuiltInLocalInvocationId.y;
+}
+SYCL_EXTERNAL inline size_t __spirv_LocalInvocationId_z() {
+  return __spirv_BuiltInLocalInvocationId.z;
+}
+
+#endif // __SYCL_NVPTX__
+
+#define DEFINE_FUNC_ID_TO_XYZ_CONVERTER(POSTFIX)                               \
+  template <int ID> static inline size_t get##POSTFIX();                       \
+  template <> size_t get##POSTFIX<0>() { return __spirv_##POSTFIX##_x(); }     \
+  template <> size_t get##POSTFIX<1>() { return __spirv_##POSTFIX##_y(); }     \
+  template <> size_t get##POSTFIX<2>() { return __spirv_##POSTFIX##_z(); }
+
+namespace __spirv {
+
+DEFINE_FUNC_ID_TO_XYZ_CONVERTER(GlobalInvocationId);
+DEFINE_FUNC_ID_TO_XYZ_CONVERTER(LocalInvocationId);
+
+} // namespace __spirv
+
+#undef DEFINE_FUNC_ID_TO_XYZ_CONVERTER
+
+#define DEFINE_INIT_SIZES(POSTFIX)                                             \
+                                                                               \
+  template <int Dim, class DstT> struct InitSizesST##POSTFIX;                  \
+                                                                               \
+  template <class DstT> struct InitSizesST##POSTFIX<1, DstT> {                 \
+    static DstT initSize() { return {get##POSTFIX<0>()}; }                     \
+  };                                                                           \
+                                                                               \
+  template <class DstT> struct InitSizesST##POSTFIX<2, DstT> {                 \
+    static DstT initSize() { return {get##POSTFIX<1>(), get##POSTFIX<0>()}; }  \
+  };                                                                           \
+                                                                               \
+  template <class DstT> struct InitSizesST##POSTFIX<3, DstT> {                 \
+    static DstT initSize() {                                                   \
+      return {get##POSTFIX<2>(), get##POSTFIX<1>(), get##POSTFIX<0>()};        \
+    }                                                                          \
+  };                                                                           \
+                                                                               \
+  template <int Dims, class DstT> static DstT init##POSTFIX() {                \
+    return InitSizesST##POSTFIX<Dims, DstT>::initSize();                       \
+  }
+
+namespace __spirv {
+
+DEFINE_INIT_SIZES(GlobalInvocationId)
+DEFINE_INIT_SIZES(LocalInvocationId)
+
+} // namespace __spirv
+
+#undef DEFINE_INIT_SIZES
+
+#endif // __SYCL_DEVICE_ONLY__