# This ill-named file does a number of things:
# - Installs Caffe2 header files (this has nothing to do with code generation)
# - Configures caffe2/core/macros.h
# - Creates an ATen target for its generated C++ files and adds it
#   as a dependency

################################################################################
# Helper functions
################################################################################

function(filter_list output input)
    unset(result)
    foreach(filename ${${input}})
        foreach(pattern ${ARGN})
            if("${filename}" MATCHES "${pattern}")
                list(APPEND result "${filename}")
            endif()
        endforeach()
    endforeach()
    set(${output} ${result} PARENT_SCOPE)
endfunction()

function(filter_list_exclude output input)
    unset(result)
    foreach(filename ${${input}})
        foreach(pattern ${ARGN})
            if(NOT "${filename}" MATCHES "${pattern}")
                list(APPEND result "${filename}")
            endif()
        endforeach()
    endforeach()
    set(${output} ${result} PARENT_SCOPE)
endfunction()

################################################################################

# ---[ Write the macros file
configure_file(
    ${CMAKE_CURRENT_LIST_DIR}/../caffe2/core/macros.h.in
    ${CMAKE_BINARY_DIR}/caffe2/core/macros.h)

# ---[ Installing the header files
install(DIRECTORY ${CMAKE_CURRENT_LIST_DIR}/../caffe2
        DESTINATION include
        FILES_MATCHING PATTERN "*.h")
if (NOT INTERN_BUILD_ATEN_OPS)
  install(DIRECTORY ${CMAKE_CURRENT_LIST_DIR}/../aten/src/ATen/core
          DESTINATION include/ATen
          FILES_MATCHING PATTERN "*.h")
endif()
install(FILES ${CMAKE_BINARY_DIR}/caffe2/core/macros.h
        DESTINATION include/caffe2/core)

# ---[ ATen specific
if (INTERN_BUILD_ATEN_OPS)
  SET(OPT_FLAG "-O3 ")
  IF(MSVC)
    SET(OPT_FLAG "/Ox /fp:strict ")
  ENDIF()
  SET(VCOMP_LIB "vcomp")

  IF("${CMAKE_BUILD_TYPE}" MATCHES "Debug")
    SET(OPT_FLAG " ")
    SET(VCOMP_LIB "vcompd")
  ENDIF()

  IF(C_AVX_FOUND)
    IF(MSVC)
      SET_SOURCE_FILES_PROPERTIES(${CMAKE_CURRENT_LIST_DIR}/../aten/src/TH/vector/AVX.cpp PROPERTIES COMPILE_FLAGS "${OPT_FLAG}/arch:AVX ${CXX_AVX_FLAGS}")
    ELSE(MSVC)
      SET_SOURCE_FILES_PROPERTIES(${CMAKE_CURRENT_LIST_DIR}/../aten/src/TH/vector/AVX.cpp PROPERTIES COMPILE_FLAGS "${OPT_FLAG} ${CXX_AVX_FLAGS}")
    ENDIF(MSVC)
  ENDIF(C_AVX_FOUND)

  IF(C_AVX2_FOUND)
    IF(MSVC)
      SET_SOURCE_FILES_PROPERTIES(${CMAKE_CURRENT_LIST_DIR}/../aten/src/TH/vector/AVX2.cpp PROPERTIES COMPILE_FLAGS "${OPT_FLAG}/arch:AVX2 ${CXX_AVX2_FLAGS}")
    ELSE(MSVC)
      SET_SOURCE_FILES_PROPERTIES(${CMAKE_CURRENT_LIST_DIR}/../aten/src/TH/vector/AVX2.cpp PROPERTIES COMPILE_FLAGS "${OPT_FLAG} ${CXX_AVX2_FLAGS}")
    ENDIF(MSVC)
  ENDIF(C_AVX2_FOUND)

  IF(NOT MSVC AND NOT "${CMAKE_C_COMPILER_ID}" MATCHES "Clang")
    SET_SOURCE_FILES_PROPERTIES(${CMAKE_CURRENT_LIST_DIR}/../aten/src/TH/THAllocator.cpp PROPERTIES COMPILE_FLAGS "-fno-openmp")
  ENDIF()

  FILE(GLOB cpu_kernel_cpp_in "${CMAKE_CURRENT_LIST_DIR}/../aten/src/ATen/native/cpu/*.cpp")

  LIST(APPEND CPU_CAPABILITY_NAMES "DEFAULT")
  LIST(APPEND CPU_CAPABILITY_FLAGS "${OPT_FLAG}")

  IF(CXX_AVX_FOUND)
    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DHAVE_AVX_CPU_DEFINITION")
    LIST(APPEND CPU_CAPABILITY_NAMES "AVX")
    IF(MSVC)
      LIST(APPEND CPU_CAPABILITY_FLAGS "${OPT_FLAG}/arch:AVX")
    ELSE(MSVC)
      LIST(APPEND CPU_CAPABILITY_FLAGS "${OPT_FLAG} -mavx")
    ENDIF(MSVC)
  ENDIF(CXX_AVX_FOUND)

  IF(CXX_AVX2_FOUND)
    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DHAVE_AVX2_CPU_DEFINITION")

    # Some versions of GCC pessimistically split unaligned load and store
    # instructions when using the default tuning. This is a bad choice on
    # new Intel and AMD processors so we disable it when compiling with AVX2.
    # See https://stackoverflow.com/questions/52626726/why-doesnt-gcc-resolve-mm256-loadu-pd-as-single-vmovupd#tab-top
    check_cxx_compiler_flag("-mno-avx256-split-unaligned-load -mno-avx256-split-unaligned-store" COMPILER_SUPPORTS_NO_AVX256_SPLIT)
    IF(COMPILER_SUPPORTS_NO_AVX256_SPLIT)
      SET(CPU_NO_AVX256_SPLIT_FLAGS "-mno-avx256-split-unaligned-load -mno-avx256-split-unaligned-store")
    ENDIF(COMPILER_SUPPORTS_NO_AVX256_SPLIT)

    LIST(APPEND CPU_CAPABILITY_NAMES "AVX2")
    IF(MSVC)
      LIST(APPEND CPU_CAPABILITY_FLAGS "${OPT_FLAG}/arch:AVX2")
    ELSE(MSVC)
      LIST(APPEND CPU_CAPABILITY_FLAGS "${OPT_FLAG} -mavx2 -mfma ${CPU_NO_AVX256_SPLIT_FLAGS}")
    ENDIF(MSVC)
  ENDIF(CXX_AVX2_FOUND)

  list(LENGTH CPU_CAPABILITY_NAMES NUM_CPU_CAPABILITY_NAMES)
  math(EXPR NUM_CPU_CAPABILITY_NAMES "${NUM_CPU_CAPABILITY_NAMES}-1")

  FOREACH(i RANGE ${NUM_CPU_CAPABILITY_NAMES})
    FOREACH(IMPL ${cpu_kernel_cpp_in})
      string(REPLACE "${CMAKE_CURRENT_LIST_DIR}/../aten/src/ATen/" "" NAME ${IMPL})
      LIST(GET CPU_CAPABILITY_NAMES ${i} CPU_CAPABILITY)
      SET(NEW_IMPL ${CMAKE_BINARY_DIR}/aten/src/ATen/${NAME}.${CPU_CAPABILITY}.cpp)
      CONFIGURE_FILE(${IMPL} ${NEW_IMPL} COPYONLY)
      SET(cpu_kernel_cpp ${NEW_IMPL} ${cpu_kernel_cpp}) # Create list of copies
      LIST(GET CPU_CAPABILITY_FLAGS ${i} FLAGS)
      IF(MSVC)
        SET(MACRO_FLAG "/DCPU_CAPABILITY=${CPU_CAPABILITY} /DCPU_CAPABILITY_${CPU_CAPABILITY}")
      ELSE(MSVC)
        SET(MACRO_FLAG "-DCPU_CAPABILITY=${CPU_CAPABILITY} -DCPU_CAPABILITY_${CPU_CAPABILITY}")
      ENDIF(MSVC)
      SET_SOURCE_FILES_PROPERTIES(${NEW_IMPL} PROPERTIES COMPILE_FLAGS "${FLAGS} ${MACRO_FLAG}")
    ENDFOREACH()
  ENDFOREACH()
  list(APPEND ATen_CPU_SRCS ${cpu_kernel_cpp})

  set(cwrap_files
    ${CMAKE_CURRENT_LIST_DIR}/../aten/src/ATen/Declarations.cwrap
    ${CMAKE_CURRENT_LIST_DIR}/../aten/src/THNN/generic/THNN.h
    ${CMAKE_CURRENT_LIST_DIR}/../aten/src/THCUNN/generic/THCUNN.h
    ${CMAKE_CURRENT_LIST_DIR}/../aten/src/ATen/nn.yaml
    ${CMAKE_CURRENT_LIST_DIR}/../aten/src/ATen/native/native_functions.yaml)

  FILE(GLOB all_python "${CMAKE_CURRENT_LIST_DIR}/../aten/src/ATen/*.py")

  set(GEN_ROCM_FLAG)
  if (USE_ROCM)
    set(GEN_ROCM_FLAG --rocm)
  endif()

  SET(GEN_COMMAND
      "${PYTHON_EXECUTABLE}" ${CMAKE_CURRENT_LIST_DIR}/../aten/src/ATen/gen.py
      --source-path ${CMAKE_CURRENT_LIST_DIR}/../aten/src/ATen
      --install_dir ${CMAKE_BINARY_DIR}/aten/src/ATen
      ${GEN_ROCM_FLAG}
      ${cwrap_files}
  )

  EXECUTE_PROCESS(
      COMMAND ${GEN_COMMAND}
        --output-dependencies ${CMAKE_BINARY_DIR}/aten/src/ATen/generated_cpp.txt
      RESULT_VARIABLE RETURN_VALUE
  )
  if (NOT RETURN_VALUE EQUAL 0)
      message(STATUS ${generated_cpp})
      message(FATAL_ERROR "Failed to get generated_cpp list")
  endif()
  file(READ ${CMAKE_BINARY_DIR}/aten/src/ATen/generated_cpp.txt generated_cpp)
  file(READ ${CMAKE_BINARY_DIR}/aten/src/ATen/generated_cpp.txt-cuda cuda_generated_cpp)

  file(GLOB_RECURSE all_templates "${CMAKE_CURRENT_LIST_DIR}/../aten/src/ATen/templates/*")

  # these are files that are generated by the script and checked in -- the script checks
  # that they are equivalent so it must be a dependency of the script
  set(core_gen_checked_inputs
    ${CMAKE_CURRENT_LIST_DIR}/../aten/src/ATen/core/Tensor.h
    ${CMAKE_CURRENT_LIST_DIR}/../aten/src/ATen/core/TensorMethods.h)

  file(MAKE_DIRECTORY ${CMAKE_BINARY_DIR}/aten/src/ATen)
  file(MAKE_DIRECTORY ${CMAKE_BINARY_DIR}/aten/src/ATen/core_tmp)

  add_custom_command(OUTPUT ${generated_cpp} ${cuda_generated_cpp}
    COMMAND ${GEN_COMMAND}
    DEPENDS ${all_python} ${all_templates} ${cwrap_files} ${core_gen_checked_inputs})

  # Generated headers used from a CUDA (.cu) file are
  # not tracked correctly in CMake. We make the libATen.so depend explicitly
  # on building the generated ATen files to workaround.
  add_custom_target(ATEN_CPU_FILES_GEN_TARGET DEPENDS ${generated_cpp})
  add_custom_target(ATEN_CUDA_FILES_GEN_TARGET DEPENDS ${cuda_generated_cpp})
  add_library(ATEN_CPU_FILES_GEN_LIB INTERFACE)
  add_library(ATEN_CUDA_FILES_GEN_LIB INTERFACE)
  add_dependencies(ATEN_CPU_FILES_GEN_LIB ATEN_CPU_FILES_GEN_TARGET)
  add_dependencies(ATEN_CUDA_FILES_GEN_LIB ATEN_CUDA_FILES_GEN_TARGET)
endif()