# # COPYRIGHT
#
# All contributions by Emanuele Ruffaldi Copyright (c) 2016-2019, E All rights
# reserved.
#
# All other contributions: Copyright (c) 2019, the respective contributors. All
# rights reserved.
#
# Each contributor holds copyright over their respective contributions. The
# project versioning (Git) records all such contribution source information.
#
# LICENSE
#
# The BSD 3-Clause License
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright notice,
#   this list of conditions and the following disclaimer in the documentation
#   and/or other materials provided with the distribution.
#
# * Neither the name of tiny-dnn nor the names of its contributors may be used
#   to endorse or promote products derived from this software without specific
#   prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# SOURCE:
# https://github.com/eruffaldi/cppPosit/blob/master/include/FindInt128.cmake
#

# * this module looks for 128 bit integer support.  It sets up the type defs in
#   util/int128_types.hpp.  Simply add ${INT128_FLAGS} to the compiler flags.

include(CheckTypeSize)
include(CheckCXXSourceCompiles)

macro(CHECK_128_BIT_HASH_FUNCTION VAR_NAME DEF_NAME)

  # message("Testing for presence of 128 bit unsigned integer hash function for
  # ${VAR_NAME}.")

  check_cxx_source_compiles(
    "
  #include <functional>
  #include <cstdint>
  int main(int argc, char** argv) {
    std::hash<${VAR_NAME}>()(0);
  return 0;
  }"
    has_hash_${VAR_NAME}
  )

  if(has_hash_${VAR_NAME})
    # message("std::hash<${VAR_NAME}> defined.")
    set(${DEF_NAME} 1)
  else()
    # message("std::hash<${VAR_NAME}> not defined.")
  endif()
endmacro()

macro(CHECK_INT128 INT128_NAME VARIABLE DEFINE_NAME)

  if(NOT INT128_FOUND)
    # message("Testing for 128 bit integer support with ${INT128_NAME}.")
    check_type_size("${INT128_NAME}" int128_t_${DEFINE_NAME})
    if(HAVE_int128_t_${DEFINE_NAME})
      if(int128_t_${DEFINE_NAME} EQUAL 16)
        # message("Found: Enabling support for 128 bit integers using
        # ${INT128_NAME}.")
        set(INT128_FOUND 1)
        check_128_bit_hash_function(${INT128_NAME} HAS_INT128_STD_HASH)
        set(${VARIABLE} "${DEFINE_NAME}")
      else()
        # message("${INT128_NAME} has incorrect size, can't use.")
      endif()
    endif()
  endif()
endmacro()

macro(CHECK_UINT128 UINT128_NAME VARIABLE DEFINE_NAME)

  if(NOT UINT128_FOUND)
    # message("Testing for 128 bit unsigned integer support with
    # ${UINT128_NAME}.")
    check_type_size("${UINT128_NAME}" uint128_t_${DEFINE_NAME})
    if(HAVE_uint128_t_${DEFINE_NAME})
      if(uint128_t_${DEFINE_NAME} EQUAL 16)
        # message("Found: Enabling support for 128 bit integers using
        # ${UINT128_NAME}.")
        set(UINT128_FOUND 1)
        check_128_bit_hash_function(${UINT128_NAME} HAS_UINT128_STD_HASH)
        set(${VARIABLE} "${DEFINE_NAME}")
      else()
        # message("${UINT128_NAME} has incorrect size, can't use.")
      endif()
    endif()
  endif()
endmacro()

macro(FIND_INT128_TYPES)

  check_int128("long long" INT128_DEF "HAVEint128_as_long_long")
  check_int128("int128_t" INT128_DEF "HAVEint128_t")
  check_int128("__int128_t" INT128_DEF "HAVE__int128_t")
  check_int128("__int128" INT128_DEF "HAVE__int128")
  check_int128("int128" INT128_DEF "HAVEint128")

  if(INT128_FOUND)
    set(INT128_FLAGS "-D${INT128_DEF}")
    if(HAS_INT128_STD_HASH)
      set(INT128_FLAGS "${INT128_FLAGS} -DHASH_FOR_INT128_DEFINED")
    endif()
  endif()

  check_uint128("unsigned long long" UINT128_DEF "HAVEuint128_as_u_long_long")
  check_uint128("uint128_t" UINT128_DEF "HAVEuint128_t")
  check_uint128("__uint128_t" UINT128_DEF "HAVE__uint128_t")
  check_uint128("__uint128" UINT128_DEF "HAVE__uint128")
  check_uint128("uint128" UINT128_DEF "HAVEuint128")
  check_uint128("unsigned __int128_t" UINT128_DEF "HAVEunsigned__int128_t")
  check_uint128("unsigned int128_t" UINT128_DEF "HAVEunsignedint128_t")
  check_uint128("unsigned __int128" UINT128_DEF "HAVEunsigned__int128")
  check_uint128("unsigned int128" UINT128_DEF "HAVEunsignedint128")

  if(UINT128_FOUND)
    set(INT128_FLAGS "${INT128_FLAGS} -D${UINT128_DEF}")
    if(HAS_UINT128_STD_HASH)
      set(INT128_FLAGS "${INT128_FLAGS} -DHASH_FOR_UINT128_DEFINED")
    endif()
  endif()

  # MSVC doesn't support 128 bit soft operations, which is weird since they
  # support 128 bit numbers... Clang does support, but didn't expose them
  # https://reviews.llvm.org/D41813
  if(${MSVC})
    set(UINT128_FOUND False)
  endif()
endmacro()