68 lines
1.5 KiB
C
68 lines
1.5 KiB
C
/*
|
|
* ====================================================
|
|
* x87 FP implementation contributed to Newlib by
|
|
* Dave Korn, November 2007. This file is placed in the
|
|
* public domain. Permission to use, copy, modify, and
|
|
* distribute this software is freely granted.
|
|
* ====================================================
|
|
*/
|
|
|
|
#if defined(__GNUC__) && !defined(_SOFT_FLOAT)
|
|
|
|
#include <math.h>
|
|
|
|
/*
|
|
FUNCTION
|
|
<<rint>>, <<rintf>>, <<rintl>>---round to integer
|
|
INDEX
|
|
rint
|
|
INDEX
|
|
rintf
|
|
INDEX
|
|
rintl
|
|
|
|
ANSI_SYNOPSIS
|
|
#include <math.h>
|
|
double rint(double x);
|
|
float rintf(float x);
|
|
long double rintl(long double x);
|
|
|
|
TRAD_SYNOPSIS
|
|
ANSI-only.
|
|
|
|
DESCRIPTION
|
|
The <<rint>>, <<rintf>> and <<rintl>> functions round <[x]> to an integer value
|
|
in floating-point format, using the current rounding direction. They may
|
|
raise the inexact exception if the result differs in value from the argument.
|
|
|
|
RETURNS
|
|
These functions return the rounded integer value of <[x]>.
|
|
|
|
PORTABILITY
|
|
<<rint>>, <<rintf>> and <<rintl>> are ANSI.
|
|
<<rint>> and <<rintf>> are available on all platforms.
|
|
<<rintl>> is only available on i386 platforms when hardware
|
|
floating point support is available and when compiling with GCC.
|
|
|
|
*/
|
|
|
|
/*
|
|
* Fast math version of rint(x)
|
|
* Return x rounded to integral value according to the prevailing
|
|
* rounding mode.
|
|
* Method:
|
|
* Using inline x87 asms.
|
|
* Exception:
|
|
* Governed by x87 FPCR.
|
|
*/
|
|
|
|
double _f_rint (double x)
|
|
{
|
|
double _result;
|
|
asm ("frndint" : "=t" (_result) : "0" (x));
|
|
return _result;
|
|
}
|
|
|
|
#endif /* !__GNUC__ || _SOFT_FLOAT */
|
|
|