Files
UnrealEngine/Engine/Source/ThirdParty/libSampleRate/Private/float_cast.h
2025-05-18 13:04:45 +08:00

78 lines
2.1 KiB
C

#pragma once
/*
** Copyright (c) 2001-2016, Erik de Castro Lopo <erikd@mega-nerd.com>
** All rights reserved.
**
** This code is released under 2-clause BSD license. Please see the
** file at : https://github.com/erikd/libsamplerate/blob/master/COPYING
*/
/* Version 1.5 */
/*============================================================================
** On Intel Pentium processors (especially PIII and probably P4), converting
** from float to int is very slow. To meet the C specs, the code produced by
** most C compilers targeting Pentium needs to change the FPU rounding mode
** before the float to int conversion is performed.
**
** Changing the FPU rounding mode causes the FPU pipeline to be flushed. It
** is this flushing of the pipeline which is so slow.
**
** Fortunately the ISO C99 specifications define the functions lrint, lrintf,
** llrint and llrintf which fix this problem as a side effect.
**
** On Unix-like systems, the configure process should have detected the
** presence of these functions. If they weren't found we have to replace them
** here with a standard C cast.
*/
/*
** The C99 prototypes for lrint and lrintf are as follows:
**
** long int lrintf (float x) ;
** long int lrint (double x) ;
*/
#include "config.h"
/*
** The presence of the required functions are detected during the configure
** process and the values HAVE_LRINT and HAVE_LRINTF are set accordingly in
** the config.h file.
*/
#define HAVE_LRINT_REPLACEMENT 0
#if !defined(HAVE_LRINT)
#define HAVE_LRINT 0
#endif
#if !defined(HAVE_LRINTF)
#define HAVE_LRINTF 0
#endif
#if (HAVE_LRINT && HAVE_LRINTF)
/*
** These defines enable functionality introduced with the 1999 ISO C
** standard. They must be defined before the inclusion of math.h to
** engage them. If optimisation is enabled, these functions will be
** inlined. With optimisation switched off, you have to link in the
** maths library using -lm.
*/
#define _ISOC9X_SOURCE 1
#define _ISOC99_SOURCE 1
#define __USE_ISOC9X 1
#define __USE_ISOC99 1
#include <math.h>
#else
#define lrint(dbl) ((long) (dbl))
#define lrintf(flt) ((long) (flt))
#endif