Merge pull request #24286 from ashadrina:intel_icx_compiler_support

Add Intel® oneAPI DPC++/C++ Compiler (icx) #24286

Intel® C++ Compiler Classic (icc) is deprecated and will be removed in a oneAPI release in the second half of 2023 ([deprecation notice](https://community.intel.com/t5/Intel-oneAPI-IoT-Toolkit/DEPRECATION-NOTICE-Intel-C-Compiler-Classic/m-p/1412267#:~:text=Intel%C2%AE%20C%2B%2B%20Compiler%20Classic%20(icc)%20is%20deprecated%20and%20will,the%20second%20half%20of%202023.)). This commit is intended to add support for the next-generation compiler, Intel® oneAPI DPC++/C++ Compiler (icx) (the documentation for the compiler is available on the [link](https://www.intel.com/content/www/us/en/docs/dpcpp-cpp-compiler/developer-guide-reference/2023-2/overview.html)). 

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [ ] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake

cmake/OpenCVCompilerOptimizations.cmake

@@ -224,7 +224,7 @@ if(X86 OR X86_64)
     ocv_update(CPU_SSE2_IMPLIES "SSE")
   endif()
 
-  if(CV_ICC)
+  if(CV_ICC OR CV_ICX)
     macro(ocv_intel_compiler_optimization_option name unix_flags msvc_flags)
       ocv_update(CPU_${name}_FLAGS_NAME "${name}")
       if(MSVC)
@@ -260,7 +260,7 @@ if(X86 OR X86_64)
     ocv_intel_compiler_optimization_option(AVX512_CNL "-xCANNONLAKE" "/Qx:CANNONLAKE")
     ocv_intel_compiler_optimization_option(AVX512_CLX "-xCASCADELAKE" "/Qx:CASCADELAKE")
     ocv_intel_compiler_optimization_option(AVX512_ICL "-xICELAKE-CLIENT" "/Qx:ICELAKE-CLIENT")
-  elseif(CV_GCC OR CV_CLANG)
+  elseif(CV_GCC OR CV_CLANG OR CV_ICX)
     ocv_update(CPU_AVX2_FLAGS_ON "-mavx2")
     ocv_update(CPU_FP16_FLAGS_ON "-mf16c")
     ocv_update(CPU_AVX_FLAGS_ON "-mavx")
@@ -657,7 +657,7 @@ macro(ocv_compiler_optimization_options)
 endmacro()
 
 macro(ocv_compiler_optimization_options_finalize)
-  if((CV_GCC OR CV_CLANG) AND (X86 OR X86_64))
+  if((CV_GCC OR CV_CLANG OR CV_ICX) AND (X86 OR X86_64))
     if(NOT APPLE AND CMAKE_SIZEOF_VOID_P EQUAL 4)
       if(OPENCV_EXTRA_CXX_FLAGS MATCHES "-m(sse2|avx)")
         add_extra_compiler_option(-mfpmath=sse) # !! important - be on the same wave with x64 compilers
@@ -944,7 +944,7 @@ macro(ocv_add_dispatched_file_force_all)
 endmacro()
 
 
-if(CV_DISABLE_OPTIMIZATION OR CV_ICC)
+if(CV_DISABLE_OPTIMIZATION OR CV_ICC OR CX_ICX)
   ocv_update(CV_ENABLE_UNROLLED 0)
 else()
   ocv_update(CV_ENABLE_UNROLLED 1)

cmake/OpenCVCompilerOptions.cmake

@@ -105,6 +105,19 @@ elseif(CV_ICC)
       add_extra_compiler_option("-fp-model precise")
     endif()
   endif()
+elseif(CV_ICX)
+  # ICX uses -ffast-math by default.
+  # use own flags, if no one of the flags provided by user: -fp-model, -ffast-math -fno-fast-math
+  if(NOT " ${CMAKE_CXX_FLAGS} ${OPENCV_EXTRA_FLAGS} ${OPENCV_EXTRA_CXX_FLAGS}" MATCHES " /fp:"
+      AND NOT " ${CMAKE_CXX_FLAGS} ${OPENCV_EXTRA_FLAGS} ${OPENCV_EXTRA_CXX_FLAGS}" MATCHES " -fp-model"
+      AND NOT " ${CMAKE_CXX_FLAGS} ${OPENCV_EXTRA_FLAGS} ${OPENCV_EXTRA_CXX_FLAGS}" MATCHES " -ffast-math"
+      AND NOT " ${CMAKE_CXX_FLAGS} ${OPENCV_EXTRA_FLAGS} ${OPENCV_EXTRA_CXX_FLAGS}" MATCHES " -fno-fast-math"
+  )
+    if(NOT ENABLE_FAST_MATH)
+      add_extra_compiler_option(-fno-fast-math)
+      add_extra_compiler_option(-fp-model=precise)
+    endif()
+  endif()
 elseif(CV_GCC OR CV_CLANG)
   if(ENABLE_FAST_MATH)
     add_extra_compiler_option(-ffast-math)
@@ -112,7 +125,7 @@ elseif(CV_GCC OR CV_CLANG)
   endif()
 endif()
 
-if(CV_GCC OR CV_CLANG)
+if(CV_GCC OR CV_CLANG OR CV_ICX)
   # High level of warnings.
   add_extra_compiler_option(-W)
   if (NOT MSVC)
@@ -336,7 +349,7 @@ if(COMMAND ocv_compiler_optimization_options_finalize)
 endif()
 
 # set default visibility to hidden
-if((CV_GCC OR CV_CLANG)
+if((CV_GCC OR CV_CLANG OR CV_ICX)
     AND NOT MSVC
     AND NOT OPENCV_SKIP_VISIBILITY_HIDDEN
     AND NOT " ${CMAKE_CXX_FLAGS} ${OPENCV_EXTRA_FLAGS} ${OPENCV_EXTRA_CXX_FLAGS}" MATCHES " -fvisibility")

cmake/OpenCVDetectCXXCompiler.cmake

@@ -68,6 +68,23 @@ if(MSVC AND CMAKE_C_COMPILER MATCHES "icc|icl")
   set(CV_ICC   __INTEL_COMPILER_FOR_WINDOWS)
 endif()
 
+# ----------------------------------------------------------------------------
+# Detect Intel ICXC compiler
+# ----------------------------------------------------------------------------
+if(UNIX)
+  if(__INTEL_COMPILER)
+    set(CV_ICX   __INTEL_LLVM_COMPILER)
+  elseif(CMAKE_C_COMPILER MATCHES "icx")
+    set(CV_ICX   icx_matches_c_compiler)
+  elseif(CMAKE_CXX_COMPILER MATCHES "icpx")
+    set(CV_ICX   icpx_matches_cxx_compiler)
+  endif()
+endif()
+
+if(MSVC AND CMAKE_CXX_COMPILER MATCHES ".*(dpcpp-cl|dpcpp|icx-cl|icpx|icx)(.exe)?$")
+  set(CV_ICX   __INTEL_LLVM_COMPILER_WINDOWS)
+endif()
+
 if(NOT DEFINED CMAKE_CXX_COMPILER_VERSION
     AND NOT OPENCV_SUPPRESS_MESSAGE_MISSING_COMPILER_VERSION)
   message(WARNING "OpenCV: Compiler version is not available: CMAKE_CXX_COMPILER_VERSION is not set")