satdump/cmake/FindNEON.cmake
2022-12-24 13:17:13 +01:00

98 lines
2.5 KiB
CMake

#.rst:
# FindNEON
# --------
#
# Finds NEON support
#
# This module can be used to detect NEON support in a C compiler. If
# the compiler supports NEON, the flags required to compile with
# NEON support are returned in variables for the different languages.
# The variables may be empty if the compiler does not need a special
# flag to support NEON.
#
# The following variables are set:
#
# ::
#
# NEON_C_FLAGS - flags to add to the C compiler for NEON support
# NEON_FOUND - true if NEON is detected
#
#=============================================================================
set(_NEON_REQUIRED_VARS)
set(CMAKE_REQUIRED_QUIET_SAVE ${CMAKE_REQUIRED_QUIET})
set(CMAKE_REQUIRED_QUIET ${NEON_FIND_QUIETLY})
# sample NEON source code to test
set(NEON_C_TEST_SOURCE
"
#include <arm_neon.h>
uint32x4_t double_elements(uint32x4_t input)
{
return(vaddq_u32(input, input));
}
int main(void)
{
uint32x4_t one;
uint32x4_t two = double_elements(one);
return 0;
}
")
# if these are set then do not try to find them again,
# by avoiding any try_compiles for the flags
if((DEFINED NEON_C_FLAGS) OR (DEFINED HAVE_NEON))
else()
if(WIN32)
set(NEON_C_FLAG_CANDIDATES
#Empty, if compiler automatically accepts NEON
" ")
else()
set(NEON_C_FLAG_CANDIDATES
#Empty, if compiler automatically accepts NEON
" "
"-mfpu=neon"
"-mfpu=neon -mfloat-abi=softfp"
)
endif()
include(CheckCSourceCompiles)
foreach(FLAG IN LISTS NEON_C_FLAG_CANDIDATES)
set(SAFE_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
set(CMAKE_REQUIRED_FLAGS "${FLAG}")
unset(HAVE_NEON CACHE)
if(NOT CMAKE_REQUIRED_QUIET)
message(STATUS "Try NEON C flag = [${FLAG}]")
endif()
check_c_source_compiles("${NEON_C_TEST_SOURCE}" HAVE_NEON)
set(CMAKE_REQUIRED_FLAGS "${SAFE_CMAKE_REQUIRED_FLAGS}")
if(HAVE_NEON)
set(NEON_C_FLAGS_INTERNAL "${FLAG}")
break()
endif()
endforeach()
unset(NEON_C_FLAG_CANDIDATES)
set(NEON_C_FLAGS "${NEON_C_FLAGS_INTERNAL}"
CACHE STRING "C compiler flags for NEON intrinsics")
endif()
list(APPEND _NEON_REQUIRED_VARS NEON_C_FLAGS)
set(CMAKE_REQUIRED_QUIET ${CMAKE_REQUIRED_QUIET_SAVE})
if(_NEON_REQUIRED_VARS)
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(NEON
REQUIRED_VARS ${_NEON_REQUIRED_VARS})
mark_as_advanced(${_NEON_REQUIRED_VARS})
unset(_NEON_REQUIRED_VARS)
else()
message(SEND_ERROR "FindNEON requires C or CXX language to be enabled")
endif()