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[] = "$Id: s_frexpf.c,v 1.2 1995/04/07 23:23:27 bde Exp $"; 18 #endif 19 20 #include "math.h" 21 #include "math_private.h" 22 23 #ifdef __STDC__ 24 static const float 25 #else 26 static float 27 #endif 28 two25 = 3.3554432000e+07; /* 0x4c000000 */ 29 30 #ifdef __STDC__ 31 float frexpf(float x, int *eptr) 32 #else 33 float frexpf(x, eptr) 34 float x; int *eptr; 35 #endif 36 { 37 int32_t hx,ix; 38 GET_FLOAT_WORD(hx,x); 39 ix = 0x7fffffff&hx; 40 *eptr = 0; 41 if(ix>=0x7f800000||(ix==0)) return x; /* 0,inf,nan */ 42 if (ix<0x00800000) { /* subnormal */ 43 x *= two25; 44 GET_FLOAT_WORD(hx,x); 45 ix = hx&0x7fffffff; 46 *eptr = -25; 47 } 48 *eptr += (ix>>23)-126; 49 hx = (hx&0x807fffff)|0x3f000000; 50 *(int*)&x = hx; 51 return x; 52 } 53