41 lines
1.0 KiB
C
41 lines
1.0 KiB
C
/* s_ilogbf.c -- float version of s_ilogb.c.
|
|
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@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.
|
|
* ====================================================
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
#if defined(LIBM_SCCS) && !defined(lint)
|
|
__RCSID("$NetBSD: s_ilogbf.c,v 1.7 2002/05/26 22:01:56 wiz Exp $");
|
|
#endif
|
|
|
|
#include "math.h"
|
|
#include "math_private.h"
|
|
|
|
int
|
|
ilogbf(float x)
|
|
{
|
|
int32_t hx,ix;
|
|
|
|
GET_FLOAT_WORD(hx,x);
|
|
hx &= 0x7fffffff;
|
|
if(hx<0x00800000) {
|
|
if(hx==0)
|
|
return 0x80000001; /* ilogb(0) = 0x80000001 */
|
|
else /* subnormal x */
|
|
for (ix = -126,hx<<=8; hx>0; hx<<=1) ix -=1;
|
|
return ix;
|
|
}
|
|
else if (hx<0x7f800000) return (hx>>23)-127;
|
|
else return 0x7fffffff;
|
|
}
|