shithub: libsamplerate

ref: f42f97f3312e342568f8d3cb432e44944e9768b5
dir: /cmake/ClipMode.cmake/

include (CheckCSourceRuns)
include (CMakePushCheckState)

macro (CLIP_MODE)

    set (CLIP_MODE_POSITIVE_MESSAGE "Target processor clips on positive float to int conversion")
    set (CLIP_MODE_NEGATIVE_MESSAGE "Target processor clips on negative float to int conversion")

    message (STATUS "Checking processor clipping capabilities...")

    if (CMAKE_CROSSCOMPILING)

        set (CLIP_MSG "disabled")
        set (CPU_CLIPS_POSITIVE FALSE CACHE BOOL ${CLIP_MODE_POSITIVE_MESSAGE})
        set (CPU_CLIPS_NEGATIVE FALSE CACHE BOOL ${CLIP_MODE_NEGATIVE_MESSAGE})

    else (NOT CMAKE_CROSSCOMPILING)

        cmake_push_check_state ()

        set (CMAKE_REQUIRED_QUIET TRUE)
        if (LIBM_REQUIRED)
            set (CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} ${M_LIBRARY})
        endif ()

        check_c_source_runs (
        "
        #define _ISOC9X_SOURCE  1
        #define _ISOC99_SOURCE  1
        #define __USE_ISOC99    1
        #define __USE_ISOC9X    1
        #include <math.h>
        int main (void)
        {   double  fval ;
            int k, ival ;

            fval = 1.0 * 0x7FFFFFFF ;
            for (k = 0 ; k < 100 ; k++)
            {   ival = (lrint (fval)) >> 24 ;
                if (ival != 127)
                    return 1 ;

                fval *= 1.2499999 ;
                } ;

                return 0 ;
            }
        "
        CPU_CLIPS_POSITIVE)

        check_c_source_runs (
        "
        #define _ISOC9X_SOURCE  1
        #define _ISOC99_SOURCE  1
        #define __USE_ISOC99    1
        #define __USE_ISOC9X    1
        #include <math.h>
        int main (void)
        {   double  fval ;
            int k, ival ;

            fval = -8.0 * 0x10000000 ;
            for (k = 0 ; k < 100 ; k++)
            {   ival = (lrint (fval)) >> 24 ;
                if (ival != -128)
                    return 1 ;

                fval *= 1.2499999 ;
                } ;

                return 0 ;
            }
        "
        CPU_CLIPS_NEGATIVE)

        cmake_pop_check_state ()

        if (CPU_CLIPS_POSITIVE AND (NOT CPU_CLIPS_NEGATIVE))
            set (CLIP_MSG "positive")
        elseif (CPU_CLIPS_NEGATIVE AND (NOT CPU_CLIPS_POSITIVE))
            set (CLIP_MSG "negative")
        elseif (CPU_CLIPS_POSITIVE AND CPU_CLIPS_NEGATIVE)
            set (CLIP_MSG "both")
        else ()
            set (CLIP_MSG "none")
        endif ()

    endif (CMAKE_CROSSCOMPILING)

    message (STATUS "Checking processor clipping capabilities... ${CLIP_MSG}")

endmacro (CLIP_MODE)