Add XPU compiler version control in cmake to keep BC (#139258)

# Motivation
This PR aims to maintain backward compatibility when building PyTorch XPU with the old and new compilers.

# Additional Context
The details are described here. The new compiler (2025.0.0) has some breaking changes compared with the old compiler(2024.1), for examples:
1. On Windows, sycl library is named `sycl7.lib` in the old compiler but is named `sycl.lib` in the new compiler.
2. On Linux, in order to support ABI=0, we have to link `libsycl-preview.so` in the old compiler but we could link `libsycl.so` in the new compiler to have the same ABI compatibility.
3. We added a macro `SYCL_COMPILER_VERSION` to support our new code has good backward compatibility with the old compiler. Now the new feature(Event elapsed_time, memory summary, and device architecture property) introduced by the new compiler will be controlled within the macro `SYCL_COMPILER_VERSION`.

Pull Request resolved: https://github.com/pytorch/pytorch/pull/139258
Approved by: https://github.com/EikanWang, https://github.com/atalman, https://github.com/gujinghui

cmake/Dependencies.cmake

@@ -95,11 +95,10 @@ if(USE_XPU)
     message(WARNING "Not compiling with XPU. Could NOT find SYCL."
     "Suppress this warning with -DUSE_XPU=OFF.")
     caffe2_update_option(USE_XPU OFF)
-  else()
-    if(LINUX)
-      string(APPEND CMAKE_CXX_FLAGS " -D__INTEL_PREVIEW_BREAKING_CHANGES")
-    endif()
   endif()
+  foreach(flag ${XPU_HOST_CXX_FLAGS})
+    add_definitions(${flag})
+  endforeach()
 endif()
 
 # ---[ Custom Protobuf

cmake/Modules/FindMKLDNN.cmake

@@ -42,8 +42,8 @@ IF(NOT MKLDNN_FOUND)
         list(APPEND DNNL_MAKE_COMMAND "--" "-l" "$ENV{MAX_JOBS}")
       endif()
     endif()
-    if(LINUX)
-      set(DNNL_CXX_FLAGS "-DCMAKE_CXX_FLAGS=-fpreview-breaking-changes")
+    if(XPU_DEVICE_CXX_FLAGS)
+      set(DNNL_CXX_FLAGS "-DCMAKE_CXX_FLAGS=${XPU_DEVICE_CXX_FLAGS}")
     else()
       set(DNNL_CXX_FLAGS "")
     endif()

cmake/Modules/FindSYCLToolkit.cmake

@@ -3,6 +3,7 @@
 # SYCL_INCLUDE_DIR         : Include directories needed to use SYCL.
 # SYCL_LIBRARY_DIR         ：The path to the SYCL library.
 # SYCL_LIBRARY             : SYCL library fullname.
+# SYCL_COMPILER_VERSION    : SYCL compiler version.
 
 include(FindPackageHandleStandardArgs)
 
@@ -21,6 +22,39 @@ if(nosyclfound)
   return()
 endif()
 
+# Find SYCL compiler executable.
+find_program(
+  SYCL_COMPILER
+  NAMES icx
+  PATHS "${SYCL_ROOT}"
+  PATH_SUFFIXES bin bin64
+  NO_DEFAULT_PATH
+  )
+
+function(parse_sycl_compiler_version version_number)
+  # Execute the SYCL compiler with the --version flag to match the version string.
+  execute_process(COMMAND ${SYCL_COMPILER} --version OUTPUT_VARIABLE SYCL_VERSION_STRING)
+  string(REGEX REPLACE "Intel\\(R\\) (.*) Compiler ([0-9]+\\.[0-9]+\\.[0-9]+) (.*)" "\\2"
+               SYCL_VERSION_STRING_MATCH ${SYCL_VERSION_STRING})
+  string(REPLACE "." ";" SYCL_VERSION_LIST ${SYCL_VERSION_STRING_MATCH})
+  # Split the version number list into major, minor, and patch components.
+  list(GET SYCL_VERSION_LIST 0 VERSION_MAJOR)
+  list(GET SYCL_VERSION_LIST 1 VERSION_MINOR)
+  list(GET SYCL_VERSION_LIST 2 VERSION_PATCH)
+  # Calculate the version number in the format XXXXYYZZ, using the formula (major * 10000 + minor * 100 + patch).
+  math(EXPR VERSION_NUMBER_MATCH "${VERSION_MAJOR} * 10000 + ${VERSION_MINOR} * 100 + ${VERSION_PATCH}")
+  set(${version_number} "${VERSION_NUMBER_MATCH}" PARENT_SCOPE)
+endfunction()
+
+parse_sycl_compiler_version(SYCL_COMPILER_VERSION)
+
+if(NOT SYCL_COMPILER_VERSION)
+  set(SYCL_FOUND False)
+  set(SYCL_REASON_FAILURE "Cannot parse sycl compiler version to get SYCL_COMPILER_VERSION!")
+  set(SYCL_NOT_FOUND_MESSAGE "${SYCL_REASON_FAILURE}")
+  return()
+endif()
+
 # Find include path from binary.
 find_file(
   SYCL_INCLUDE_DIR
@@ -48,36 +82,32 @@ find_file(
   NO_DEFAULT_PATH
   )
 
-# Find SYCL library fullname.
-# Don't use if(LINUX) here since this requires cmake>=3.25 and file is installed
-# and used by other projects.
-# See: https://cmake.org/cmake/help/v3.25/variable/LINUX.html
-if(CMAKE_SYSTEM_NAME MATCHES "Linux")
-  find_library(
-    SYCL_LIBRARY
-    NAMES sycl-preview
-    HINTS ${SYCL_LIBRARY_DIR}
-    NO_DEFAULT_PATH
-  )
-endif()
-# On Windows, currently there's no sycl.lib. Only sycl7.lib with version suffix,
-# where the current version of the SYCL runtime is 7.
-# Until oneAPI adds support to sycl.lib without the version suffix,
-# sycl_runtime_version needs to be hardcoded and uplifted when SYCL runtime version uplifts.
-# TODO: remove this when sycl.lib is supported on Windows
-if(WIN32)
-  set(sycl_runtime_version 7)
-  find_library(
-    SYCL_LIBRARY
-    NAMES "sycl${sycl_runtime_version}"
-    HINTS ${SYCL_LIBRARY_DIR}
-    NO_DEFAULT_PATH
-  )
-  if(SYCL_LIBRARY STREQUAL "SYCL_LIBRARY-NOTFOUND")
-    message(FATAL_ERROR "Cannot find a SYCL library on Windows")
+# Define the old version of SYCL toolkit that is compatible with the current version of PyTorch.
+set(PYTORCH_2_5_SYCL_TOOLKIT_VERSION 20249999)
+
+# By default, we use libsycl.so on Linux and sycl.lib on Windows as the SYCL library name.
+if (SYCL_COMPILER_VERSION VERSION_LESS_EQUAL PYTORCH_2_5_SYCL_TOOLKIT_VERSION)
+  # Don't use if(LINUX) here since this requires cmake>=3.25 and file is installed
+  # and used by other projects.
+  # See: https://cmake.org/cmake/help/v3.25/variable/LINUX.html
+  if(CMAKE_SYSTEM_NAME MATCHES "Linux")
+    set(sycl_lib_suffix "-preview")
+  elseif(CMAKE_SYSTEM_NAME MATCHES "Windows")
+    # On Windows, the SYCL library is named sycl7.lib until PYTORCH_2_5_SYCL_TOOLKIT_VERSION.
+    # sycl.lib is supported in the later version.
+    set(sycl_lib_sufix "7")
   endif()
 endif()
 
+# Find SYCL library fullname.
+find_library(
+  SYCL_LIBRARY
+  NAMES "sycl${sycl_lib_suffix}"
+  HINTS ${SYCL_LIBRARY_DIR}
+  NO_DEFAULT_PATH
+)
+
+# Find OpenCL library fullname, which is a dependency of oneDNN.
 find_library(
   OCL_LIBRARY
   NAMES OpenCL
@@ -85,7 +115,7 @@ find_library(
   NO_DEFAULT_PATH
 )
 
-if((NOT SYCL_INCLUDE_DIR) OR (NOT SYCL_LIBRARY_DIR) OR (NOT SYCL_LIBRARY))
+if((NOT SYCL_LIBRARY) OR (NOT OCL_LIBRARY))
   set(SYCL_FOUND False)
   set(SYCL_REASON_FAILURE "SYCL library is incomplete!!")
   set(SYCL_NOT_FOUND_MESSAGE "${SYCL_REASON_FAILURE}")
@@ -96,4 +126,6 @@ find_package_handle_standard_args(
   SYCL
   FOUND_VAR SYCL_FOUND
   REQUIRED_VARS SYCL_INCLUDE_DIR SYCL_LIBRARY_DIR SYCL_LIBRARY
-  REASON_FAILURE_MESSAGE "${SYCL_REASON_FAILURE}")
+  REASON_FAILURE_MESSAGE "${SYCL_REASON_FAILURE}"
+  VERSION_VAR SYCL_COMPILER_VERSION
+  )

cmake/Summary.cmake

@@ -122,6 +122,7 @@ function(caffe2_print_configuration_summary)
   endif()
   message(STATUS "  USE_XPU               : ${USE_XPU}")
   if(${USE_XPU})
+    message(STATUS "    SYCL compiler version : ${SYCL_COMPILER_VERSION}")
     message(STATUS "    SYCL include path   : ${SYCL_INCLUDE_DIR}")
     message(STATUS "    SYCL library        : ${SYCL_LIBRARY}")
   endif()

cmake/public/xpu.cmake

@@ -5,6 +5,9 @@ if(TARGET torch::xpurt)
   return()
 endif()
 
+set(XPU_HOST_CXX_FLAGS)
+set(XPU_DEVICE_CXX_FLAGS)
+
 # Find SYCL library.
 find_package(SYCLToolkit REQUIRED)
 if(NOT SYCL_FOUND)
@@ -33,3 +36,11 @@ set_property(
 torch_xpu_get_arch_list(XPU_ARCH_FLAGS)
 # propagate to torch-xpu-ops
 set(TORCH_XPU_ARCH_LIST ${XPU_ARCH_FLAGS})
+
+if(CMAKE_SYSTEM_NAME MATCHES "Linux" AND SYCL_COMPILER_VERSION VERSION_LESS_EQUAL PYTORCH_2_5_SYCL_TOOLKIT_VERSION)
+  # for ABI compatibility on Linux
+  string(APPEND XPU_HOST_CXX_FLAGS " -D__INTEL_PREVIEW_BREAKING_CHANGES")
+  string(APPEND XPU_DEVICE_CXX_FLAGS " -fpreview-breaking-changes")
+endif()
+
+string(APPEND XPU_HOST_CXX_FLAGS " -DSYCL_COMPILER_VERSION=${SYCL_COMPILER_VERSION}")