glibc/sysdeps/ieee754/ldbl-96/s_logbl.c
Ulrich Drepper abfbdde177 Update.
1999-07-14 00:54:57 +00:00

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)