1 /* @(#)s_frexp.c 5.1 93/09/24 */
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
10 * ====================================================
12 * $NetBSD: s_frexp.c,v 1.13 2008/09/28 18:54:55 christos Exp $
17 * x = frexp(arg,&exp);
18 * return a double fp quantity x such that 0.5 <= |x| <1.0
19 * and the corresponding binary exponent "exp". That is
21 * If arg is inf, 0.0, or NaN, then frexp(arg,&exp) returns arg
26 #include "math_private.h"
29 two54 = 1.80143985094819840000e+16; /* 0x43500000, 0x00000000 */
32 frexp(double x, int *eptr)
35 EXTRACT_WORDS(hx,lx,x);
38 if(ix>=0x7ff00000||((ix|lx)==0)) return x; /* 0,inf,nan */
39 if (ix<0x00100000) { /* subnormal */
45 *eptr += ((uint32_t)ix>>20)-1022;
46 hx = (hx&0x800fffff)|0x3fe00000;