## Check for SIMD extensions.

include(CMakePushCheckState)

function(webp_check_compiler_flag WEBP_SIMD_FLAG ENABLE_SIMD)

  if(NOT ENABLE_SIMD)

    message(STATUS "Disabling ${WEBP_SIMD_FLAG} optimization.")

    set(WEBP_HAVE_${WEBP_SIMD_FLAG} 0 PARENT_SCOPE)

    return()

  endif()

  unset(WEBP_HAVE_FLAG_${WEBP_SIMD_FLAG} CACHE)

  cmake_push_check_state()

  set(CMAKE_REQUIRED_INCLUDES ${CMAKE_CURRENT_SOURCE_DIR})

  check_c_source_compiles("

      #include \"${CMAKE_CURRENT_LIST_DIR}/../src/dsp/dsp.h\"

      int main(void) {

        #if !defined(WEBP_USE_${WEBP_SIMD_FLAG})

        this is not valid code

        #endif

        return 0;

      }

    " WEBP_HAVE_FLAG_${WEBP_SIMD_FLAG}

  )

  cmake_pop_check_state()

  if(WEBP_HAVE_FLAG_${WEBP_SIMD_FLAG})

    set(WEBP_HAVE_${WEBP_SIMD_FLAG} 1 PARENT_SCOPE)

  else()

    set(WEBP_HAVE_${WEBP_SIMD_FLAG} 0 PARENT_SCOPE)

  endif()

endfunction()

# those are included in the names of WEBP_USE_* in c++ code.

set(WEBP_SIMD_FLAGS "SSE2;SSE41;AVX2;MIPS32;MIPS_DSP_R2;NEON;MSA")

set(WEBP_SIMD_FILE_EXTENSIONS "_sse2.c;_sse41.c;_avx2.c;_mips32.c;_mips_dsp_r2.c;_neon.c;_msa.c")

if(MSVC)

  # MSVC does not have a SSE4 flag but AVX2 support implies

  # SSE4 support.

  set(SIMD_ENABLE_FLAGS "/arch:SSE2;/arch:AVX2;/arch:AVX2;;;;")

  set(SIMD_DISABLE_FLAGS)

else()

  set(SIMD_ENABLE_FLAGS "-msse2;-msse4.1;-mavx2;-mips32;-mdspr2;-mfpu=neon;-mmsa")

  set(SIMD_DISABLE_FLAGS "-mno-sse2;-mno-sse4.1;-mno-avx2;;-mno-dspr2;;-mno-msa")

endif()

set(WEBP_SIMD_FILES_TO_NOT_INCLUDE)

set(WEBP_SIMD_FILES_TO_INCLUDE)

set(WEBP_SIMD_FLAGS_TO_INCLUDE)

if(${ANDROID})

  if(${ANDROID_ABI} STREQUAL "armeabi-v7a")

    # This is because Android studio uses the configuration

    # "-march=armv7-a -mfloat-abi=softfp -mfpu=vfpv3-d16"

    # that does not trigger neon optimizations but should

    # (as this configuration does not exist anymore).

    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -mfpu=neon ")

  endif()

endif()

list(LENGTH WEBP_SIMD_FLAGS WEBP_SIMD_FLAGS_LENGTH)

math(EXPR WEBP_SIMD_FLAGS_RANGE "${WEBP_SIMD_FLAGS_LENGTH} - 1")

foreach(I_SIMD RANGE ${WEBP_SIMD_FLAGS_RANGE})

  list(GET WEBP_SIMD_FLAGS ${I_SIMD} WEBP_SIMD_FLAG)

  # First try with no extra flag added as the compiler might have default flags

  # (especially on Android).

  unset(WEBP_HAVE_${WEBP_SIMD_FLAG} CACHE)

  cmake_push_check_state()

  set(CMAKE_REQUIRED_FLAGS)

  webp_check_compiler_flag(${WEBP_SIMD_FLAG} ${WEBP_ENABLE_SIMD})

  if(NOT WEBP_HAVE_${WEBP_SIMD_FLAG})

    list(GET SIMD_ENABLE_FLAGS ${I_SIMD} SIMD_COMPILE_FLAG)

    set(CMAKE_REQUIRED_FLAGS ${SIMD_COMPILE_FLAG})

    webp_check_compiler_flag(${WEBP_SIMD_FLAG} ${WEBP_ENABLE_SIMD})

  else()

    set(SIMD_COMPILE_FLAG " ")

  endif()

  # Check which files we should include or not.

  list(GET WEBP_SIMD_FILE_EXTENSIONS ${I_SIMD} WEBP_SIMD_FILE_EXTENSION)

  file(GLOB SIMD_FILES "${CMAKE_CURRENT_LIST_DIR}/../"

    "src/dsp/*${WEBP_SIMD_FILE_EXTENSION}"

  )

  if(WEBP_HAVE_${WEBP_SIMD_FLAG})

    # Memorize the file and flags.

    foreach(FILE ${SIMD_FILES})

      list(APPEND WEBP_SIMD_FILES_TO_INCLUDE ${FILE})

      list(APPEND WEBP_SIMD_FLAGS_TO_INCLUDE ${SIMD_COMPILE_FLAG})

    endforeach()

  else()

    # Remove the file from the list.

    foreach(FILE ${SIMD_FILES})

      list(APPEND WEBP_SIMD_FILES_NOT_TO_INCLUDE ${FILE})

    endforeach()

    # Explicitly disable SIMD.

    if(SIMD_DISABLE_FLAGS)

      list(GET SIMD_DISABLE_FLAGS ${I_SIMD} SIMD_COMPILE_FLAG)

      include(CheckCCompilerFlag)

      if(SIMD_COMPILE_FLAG)

        unset(HAS_COMPILE_FLAG CACHE)

        check_c_compiler_flag(${SIMD_COMPILE_FLAG} HAS_COMPILE_FLAG)

        if(HAS_COMPILE_FLAG)

          # Do one more check for Clang to circumvent CMake issue 13194.

          if(COMMAND check_compiler_flag_common_patterns)

            # Only in CMake 3.0 and above.

            check_compiler_flag_common_patterns(COMMON_PATTERNS)

          else()

            set(COMMON_PATTERNS)

          endif()

          set(CMAKE_REQUIRED_DEFINITIONS ${SIMD_COMPILE_FLAG})

          check_c_source_compiles("int main(void) {return 0;}"

            FLAG_${SIMD_COMPILE_FLAG}

            FAIL_REGEX "warning: argument unused during compilation:"

            ${COMMON_PATTERNS}

          )

          if(NOT FLAG_${SIMD_COMPILE_FLAG})

            unset(HAS_COMPILE_FLAG CACHE)

          endif()

        endif()

        if(HAS_COMPILE_FLAG)

          set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${SIMD_COMPILE_FLAG}")

        endif()

      endif()

    endif()

  endif()

  cmake_pop_check_state()

endforeach()