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 1994/08/18 23:06:51 jtc 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 one = 1.0000000000e+00, /* 0x3F800000 */ 29 two25 = 3.3554432000e+07; /* 0x4c000000 */ 30 31 #ifdef __STDC__ 32 float frexpf(float x, int *eptr) 33 #else 34 float frexpf(x, eptr) 35 float x; int *eptr; 36 #endif 37 { 38 int32_t hx,ix; 39 GET_FLOAT_WORD(hx,x); 40 ix = 0x7fffffff&hx; 41 *eptr = 0; 42 if(ix>=0x7f800000||(ix==0)) return x; /* 0,inf,nan */ 43 if (ix<0x00800000) { /* subnormal */ 44 x *= two25; 45 GET_FLOAT_WORD(hx,x); 46 ix = hx&0x7fffffff; 47 *eptr = -25; 48 } 49 *eptr += (ix>>23)-126; 50 hx = (hx&0x807fffff)|0x3f000000; 51 *(int*)&x = hx; 52 return x; 53 } 54