# Copyright 2019 The libgav1 Authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

if(LIBGAV1_CMAKE_LIBGAV1_INTRINSICS_CMAKE_)
  return()
endif() # LIBGAV1_CMAKE_LIBGAV1_INTRINSICS_CMAKE_
set(LIBGAV1_CMAKE_LIBGAV1_INTRINSICS_CMAKE_ 1)

# Returns the compiler flag for the SIMD intrinsics suffix specified by the
# SUFFIX argument via the variable specified by the VARIABLE argument:
# libgav1_get_intrinsics_flag_for_suffix(SUFFIX <suffix> VARIABLE <var name>)
macro(libgav1_get_intrinsics_flag_for_suffix)
  unset(intrinsics_SUFFIX)
  unset(intrinsics_VARIABLE)
  unset(optional_args)
  unset(multi_value_args)
  set(single_value_args SUFFIX VARIABLE)
  cmake_parse_arguments(intrinsics "${optional_args}" "${single_value_args}"
                        "${multi_value_args}" ${ARGN})

  if(NOT (intrinsics_SUFFIX AND intrinsics_VARIABLE))
    message(FATAL_ERROR "libgav1_get_intrinsics_flag_for_suffix: SUFFIX and "
                        "VARIABLE required.")
  endif()

  if(intrinsics_SUFFIX MATCHES "neon")
    if(NOT MSVC)
      set(${intrinsics_VARIABLE} "${LIBGAV1_NEON_INTRINSICS_FLAG}")
    endif()
  elseif(intrinsics_SUFFIX MATCHES "avx2")
    if(MSVC)
      set(${intrinsics_VARIABLE} "/arch:AVX2")
    else()
      set(${intrinsics_VARIABLE} "-mavx2")
    endif()
  elseif(intrinsics_SUFFIX MATCHES "sse4")
    if(NOT MSVC)
      set(${intrinsics_VARIABLE} "-msse4.1")
    endif()
  else()
    message(FATAL_ERROR "libgav1_get_intrinsics_flag_for_suffix: Unknown "
                        "instrinics suffix: ${intrinsics_SUFFIX}")
  endif()

  if(LIBGAV1_VERBOSE GREATER 1)
    message("libgav1_get_intrinsics_flag_for_suffix: "
            "suffix:${intrinsics_SUFFIX} flag:${${intrinsics_VARIABLE}}")
  endif()
endmacro()

# Processes source files specified by SOURCES and adds intrinsics flags as
# necessary: libgav1_process_intrinsics_sources(SOURCES <sources>)
#
# Detects requirement for intrinsics flags using source file name suffix.
# Currently supports AVX2 and SSE4.1.
macro(libgav1_process_intrinsics_sources)
  unset(arg_TARGET)
  unset(arg_SOURCES)
  unset(optional_args)
  set(single_value_args TARGET)
  set(multi_value_args SOURCES)
  cmake_parse_arguments(arg "${optional_args}" "${single_value_args}"
                        "${multi_value_args}" ${ARGN})
  if(NOT (arg_TARGET AND arg_SOURCES))
    message(FATAL_ERROR "libgav1_process_intrinsics_sources: TARGET and "
                        "SOURCES required.")
  endif()

  if(LIBGAV1_ENABLE_AVX2 AND libgav1_have_avx2)
    unset(avx2_sources)
    list(APPEND avx2_sources ${arg_SOURCES})

    list(FILTER avx2_sources INCLUDE REGEX
         "${libgav1_avx2_source_file_suffix}$")

    if(avx2_sources)
      unset(avx2_flags)
      libgav1_get_intrinsics_flag_for_suffix(SUFFIX
                                             ${libgav1_avx2_source_file_suffix}
                                             VARIABLE avx2_flags)
      if(avx2_flags)
        libgav1_set_compiler_flags_for_sources(SOURCES ${avx2_sources} FLAGS
                                               ${avx2_flags})
      endif()
    endif()
  endif()

  if(LIBGAV1_ENABLE_SSE4_1 AND libgav1_have_sse4)
    unset(sse4_sources)
    list(APPEND sse4_sources ${arg_SOURCES})

    list(FILTER sse4_sources INCLUDE REGEX
         "${libgav1_sse4_source_file_suffix}$")

    if(sse4_sources)
      unset(sse4_flags)
      libgav1_get_intrinsics_flag_for_suffix(SUFFIX
                                             ${libgav1_sse4_source_file_suffix}
                                             VARIABLE sse4_flags)
      if(sse4_flags)
        libgav1_set_compiler_flags_for_sources(SOURCES ${sse4_sources} FLAGS
                                               ${sse4_flags})
      endif()
    endif()
  endif()

  if(LIBGAV1_ENABLE_NEON AND libgav1_have_neon)
    unset(neon_sources)
    list(APPEND neon_sources ${arg_SOURCES})
    list(FILTER neon_sources INCLUDE REGEX
         "${libgav1_neon_source_file_suffix}$")

    if(neon_sources AND LIBGAV1_NEON_INTRINSICS_FLAG)
      unset(neon_flags)
      libgav1_get_intrinsics_flag_for_suffix(SUFFIX
                                             ${libgav1_neon_source_file_suffix}
                                             VARIABLE neon_flags)
      if(neon_flags)
        libgav1_set_compiler_flags_for_sources(SOURCES ${neon_sources} FLAGS
                                               ${neon_flags})
      endif()
    endif()
  endif()
endmacro()