This work is based in part on code from NetBSD libm, libc and kernel. The library is partly public domain and partly BSD-style licensed.
46 lines
1.1 KiB
C
46 lines
1.1 KiB
C
/* s_frexpf.c -- float version of s_frexp.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_frexpf.c,v 1.10 2007/08/21 20:12:27 drochner Exp $");
|
|
#endif
|
|
|
|
#include "math.h"
|
|
#include "math_private.h"
|
|
|
|
static const float
|
|
two25 = 3.3554432000e+07; /* 0x4c000000 */
|
|
|
|
float
|
|
frexpf(float x, int *eptr)
|
|
{
|
|
int32_t hx,ix;
|
|
GET_FLOAT_WORD(hx,x);
|
|
ix = 0x7fffffff&hx;
|
|
*eptr = 0;
|
|
if(ix>=0x7f800000||(ix==0)) return x; /* 0,inf,nan */
|
|
if (ix<0x00800000) { /* subnormal */
|
|
x *= two25;
|
|
GET_FLOAT_WORD(hx,x);
|
|
ix = hx&0x7fffffff;
|
|
*eptr = -25;
|
|
}
|
|
*eptr += (ix>>23)-126;
|
|
hx = (hx&0x807fffff)|0x3f000000;
|
|
SET_FLOAT_WORD(x,hx);
|
|
return x;
|
|
}
|