mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-25 06:20:06 +00:00
42 lines
1.1 KiB
C
42 lines
1.1 KiB
C
/* s_logbl.c -- long double version of s_logb.c.
|
|
* Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
|
|
*/
|
|
|
|
/*
|
|
* ====================================================
|
|
* 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>
|
|
|
|
long double __logbl(long double x)
|
|
{
|
|
int64_t lx,hx;
|
|
GET_LDOUBLE_WORDS64(hx,lx,x);
|
|
hx &= 0x7fffffffffffffffLL; /* high |x| */
|
|
if((hx|lx)==0) return -1.0/fabs(x);
|
|
if(hx>=0x7fff000000000000LL) return x*x;
|
|
if((hx>>=48)==0) /* IEEE 754 logb */
|
|
return -16382.0;
|
|
else
|
|
return (long double) (hx-0x3fff);
|
|
}
|
|
weak_alias (__logbl, logbl)
|