1 /* sf_frexp.c -- float version of s_frexp.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
4
5 /*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 *
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
12 * is preserved.
13 * ====================================================
14 */
15
16 #include "fdlibm.h"
17
18 static const float two25 = 3.3554432000e+07; /* 0x4c000000 */
19
20 float
frexpf(float x,int * eptr)21 frexpf(float x, int *eptr)
22 {
23 __int32_t hx, ix;
24 GET_FLOAT_WORD(hx, x);
25 ix = 0x7fffffff & hx;
26 *eptr = 0;
27 if (!FLT_UWORD_IS_FINITE(ix) || FLT_UWORD_IS_ZERO(ix))
28 return x + x; /* 0,inf,nan */
29 if (FLT_UWORD_IS_SUBNORMAL(ix)) { /* subnormal */
30 x *= two25;
31 GET_FLOAT_WORD(hx, x);
32 ix = hx & 0x7fffffff;
33 *eptr = -25;
34 }
35 *eptr += (ix >> 23) - 126;
36 hx = (hx & 0x807fffff) | 0x3f000000;
37 SET_FLOAT_WORD(x, hx);
38 return x;
39 }
40
41 _MATH_ALIAS_f_fI(frexp)
42
