Cycles: Add support for rendering on Intel GPUs using oneAPI

This patch adds a new Cycles device with similar functionality to the
existing GPU devices.  Kernel compilation and runtime interaction happen
via oneAPI DPC++ compiler and SYCL API.

This implementation is primarly focusing on Intel® Arc™ GPUs and other
future Intel GPUs.  The first supported drivers are 101.1660 on Windows
and 22.10.22597 on Linux.

The necessary tools for compilation are:
- A SYCL compiler such as oneAPI DPC++ compiler or
  https://github.com/intel/llvm
- Intel® oneAPI Level Zero which is used for low level device queries:
  https://github.com/oneapi-src/level-zero
- To optionally generate prebuilt graphics binaries: Intel® Graphics
  Compiler All are included in Linux precompiled libraries on svn:
  https://svn.blender.org/svnroot/bf-blender/trunk/lib The same goes for
  Windows precompiled binaries but for the graphics compiler, available
  as "Intel® Graphics Offline Compiler for OpenCL™ Code" from
  https://www.intel.com/content/www/us/en/developer/articles/tool/oneapi-standalone-components.html,
  for which path can be set as OCLOC_INSTALL_DIR.

Being based on the open SYCL standard, this implementation could also be
extended to run on other compatible non-Intel hardware in the future.

Reviewed By: sergey, brecht

Differential Revision: https://developer.blender.org/D15254

Co-authored-by: Nikita Sirgienko <nikita.sirgienko@intel.com>
Co-authored-by: Stefan Werner <stefan.werner@intel.com>

2 files changed, 144 insertions, 0 deletions

diff --git a/build_files/cmake/Modules/FindLevelZero.cmake b/build_files/cmake/Modules/FindLevelZero.cmake
new file mode 100644
index 00000000000..a60d8ba9978
--- /dev/null
+++ b/build_files/cmake/Modules/FindLevelZero.cmake
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright 2021-2022 Intel Corporation
+
+# - Find Level Zero library
+# Find Level Zero headers and libraries needed by oneAPI implementation
+# This module defines
+#  LEVEL_ZERO_LIBRARY, libraries to link against in order to use L0.
+#  LEVEL_ZERO_INCLUDE_DIR, directories where L0 headers can be found.
+#  LEVEL_ZERO_ROOT_DIR, The base directory to search for L0 files.
+#                 This can also be an environment variable.
+#  LEVEL_ZERO_FOUND, If false, then don't try to use L0.
+
+IF(NOT LEVEL_ZERO_ROOT_DIR AND NOT $ENV{LEVEL_ZERO_ROOT_DIR} STREQUAL "")
+  SET(LEVEL_ZERO_ROOT_DIR $ENV{LEVEL_ZERO_ROOT_DIR})
+ENDIF()
+
+SET(_level_zero_search_dirs
+  ${LEVEL_ZERO_ROOT_DIR}
+  /usr/lib
+  /usr/local/lib
+)
+
+FIND_LIBRARY(_LEVEL_ZERO_LIBRARY
+  NAMES
+    ze_loader
+  HINTS
+    ${_level_zero_search_dirs}
+  PATH_SUFFIXES
+    lib64 lib
+)
+
+FIND_PATH(_LEVEL_ZERO_INCLUDE_DIR
+  NAMES
+    level_zero/ze_api.h
+  HINTS
+    ${_level_zero_search_dirs}
+  PATH_SUFFIXES
+    include
+)
+
+INCLUDE(FindPackageHandleStandardArgs)
+
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(LevelZero DEFAULT_MSG _LEVEL_ZERO_LIBRARY _LEVEL_ZERO_INCLUDE_DIR)
+
+IF(LevelZero_FOUND)
+  SET(LEVEL_ZERO_LIBRARY ${_LEVEL_ZERO_LIBRARY})
+  SET(LEVEL_ZERO_INCLUDE_DIR ${_LEVEL_ZERO_INCLUDE_DIR} ${_LEVEL_ZERO_INCLUDE_PARENT_DIR})
+  SET(LEVEL_ZERO_FOUND TRUE)
+ELSE()
+  SET(LEVEL_ZERO_FOUND FALSE)
+ENDIF()
+
+MARK_AS_ADVANCED(
+  LEVEL_ZERO_LIBRARY
+  LEVEL_ZERO_INCLUDE_DIR
+)
diff --git a/build_files/cmake/Modules/FindSYCL.cmake b/build_files/cmake/Modules/FindSYCL.cmake
new file mode 100644
index 00000000000..ac90cbfbe43
--- /dev/null
+++ b/build_files/cmake/Modules/FindSYCL.cmake
@@ -0,0 +1,88 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright 2021-2022 Intel Corporation
+
+# - Find SYCL library
+# Find the native SYCL header and libraries needed by oneAPI implementation
+# This module defines
+#  SYCL_COMPILER, compiler which will be used for compilation of SYCL code
+#  SYCL_LIBRARY, libraries to link against in order to use SYCL.
+#  SYCL_INCLUDE_DIR, directories where SYCL headers can be found
+#  SYCL_ROOT_DIR, The base directory to search for SYCL files.
+#                 This can also be an environment variable.
+#  SYCL_FOUND, If false, then don't try to use SYCL.
+
+IF(NOT SYCL_ROOT_DIR AND NOT $ENV{SYCL_ROOT_DIR} STREQUAL "")
+  SET(SYCL_ROOT_DIR $ENV{SYCL_ROOT_DIR})
+ENDIF()
+
+SET(_sycl_search_dirs
+  ${SYCL_ROOT_DIR}
+  /usr/lib
+  /usr/local/lib
+  /opt/intel/oneapi/compiler/latest/linux/
+  C:/Program\ Files\ \(x86\)/Intel/oneAPI/compiler/latest/windows
+)
+
+# Find DPC++ compiler.
+# Since the compiler name is possibly conflicting with the system-wide
+# CLang start with looking for either dpcpp or clang binary in the given
+# list of search paths only. If that fails, try to look for a system-wide
+# dpcpp binary.
+FIND_PROGRAM(SYCL_COMPILER
+  NAMES
+    dpcpp
+    clang++
+  HINTS
+    ${_sycl_search_dirs}
+  PATH_SUFFIXES
+    bin
+  NO_CMAKE_FIND_ROOT_PATH
+  NAMES_PER_DIR
+)
+
+# NOTE: No clang++ here so that we do not pick up a system-wide CLang
+# compiler.
+if(NOT SYCL_COMPILER)
+  FIND_PROGRAM(SYCL_COMPILER
+   NAMES
+      dpcpp
+    HINTS
+      ${_sycl_search_dirs}
+    PATH_SUFFIXES
+      bin
+  )
+endif()
+
+FIND_LIBRARY(SYCL_LIBRARY
+  NAMES
+    sycl
+  HINTS
+    ${_sycl_search_dirs}
+  PATH_SUFFIXES
+    lib64 lib
+)
+
+FIND_PATH(SYCL_INCLUDE_DIR
+  NAMES
+    CL/sycl.hpp
+  HINTS
+    ${_sycl_search_dirs}
+  PATH_SUFFIXES
+    include
+    include/sycl
+)
+
+INCLUDE(FindPackageHandleStandardArgs)
+
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(SYCL DEFAULT_MSG SYCL_LIBRARY SYCL_INCLUDE_DIR)
+
+IF(SYCL_FOUND)
+  get_filename_component(_SYCL_INCLUDE_PARENT_DIR ${SYCL_INCLUDE_DIR} DIRECTORY)
+  SET(SYCL_INCLUDE_DIR ${SYCL_INCLUDE_DIR} ${_SYCL_INCLUDE_PARENT_DIR})
+ELSE()
+  SET(SYCL_SYCL_FOUND FALSE)
+ENDIF()
+
+MARK_AS_ADVANCED(
+  _SYCL_INCLUDE_PARENT_DIR
+)