s_frexpf.c (1118B)
1 /* s_frexpf.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 #ifndef lint 17 static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_frexpf.c,v 1.8 2002/05/28 18:15:04 alfred Exp $"; 18 #endif 19 20 #include "math.h" 21 #include "math_private.h" 22 23 static const float 24 two25 = 3.3554432000e+07; /* 0x4c000000 */ 25 26 float 27 frexpf(float x, int *eptr) 28 { 29 int32_t hx,ix; 30 GET_FLOAT_WORD(hx,x); 31 ix = 0x7fffffff&hx; 32 *eptr = 0; 33 if(ix>=0x7f800000||(ix==0)) return x; /* 0,inf,nan */ 34 if (ix<0x00800000) { /* subnormal */ 35 x *= two25; 36 GET_FLOAT_WORD(hx,x); 37 ix = hx&0x7fffffff; 38 *eptr = -25; 39 } 40 *eptr += (ix>>23)-126; 41 hx = (hx&0x807fffff)|0x3f000000; 42 *(int*)&x = hx; 43 return x; 44 }