mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-28 21:41:08 +00:00
48 lines
1.1 KiB
C
48 lines
1.1 KiB
C
|
/* s_logbl.c -- long double version of s_logb.c.
|
||
|
|
* Conversion to long double by Ulrich Drepper,
|
||
|
|
* Cygnus Support, drepper@cygnus.com.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
* ====================================================
|
||
|
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
||
|
|
*
|
||
|
|
* Developed at SunPro, a Sun Microsystems, Inc. business.
|
||
|
|
* Permission to use, copy, modify, and distribute this
|
||
|
|
* software is freely granted, provided that this notice
|
||
|
|
* is preserved.
|
||
|
|
* ====================================================
|
||
|
|
*/
|
||
|
|
|
||
|
|
#if defined(LIBM_SCCS) && !defined(lint)
|
||
|
|
static char rcsid[] = "$NetBSD: $";
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/*
|
||
|
|
* long double logbl(x)
|
||
|
|
* IEEE 754 logb. Included to pass IEEE test suite. Not recommend.
|
||
|
|
* Use ilogb instead.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "math.h"
|
||
|
|
#include "math_private.h"
|
||
|
|
|
||
|
|
#ifdef __STDC__
|
||
|
|
long double __logbl(long double x)
|
||
|
|
#else
|
||
|
|
long double __logbl(x)
|
||
|
|
long double x;
|
||
|
|
#endif
|
||
|
|
{
|
||
|
|
int32_t es,lx,ix;
|
||
|
|
GET_LDOUBLE_WORDS(es,ix,lx,x);
|
||
|
|
es &= 0x7fff; /* exponent */
|
||
|
|
if((es|ix|lx)==0) return -1.0/fabs(x);
|
||
|
|
if(es==0x7fff) return x*x;
|
||
|
|
if(es==0) /* IEEE 754 logb */
|
||
|
|
return -16382.0;
|
||
|
|
else
|
||
|
|
return (long double) (es-0x3fff);
|
||
|
|
}
|
||
|
|
weak_alias (__logbl, logbl)
|