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 #include <sys/cdefs.h> 17 #if defined(LIBM_SCCS) && !defined(lint) 18 __RCSID("$NetBSD: s_frexpf.c,v 1.6 1997/10/09 11:32:10 lukem Exp $"); 19 #endif 20 21 #include "math.h" 22 #include "math_private.h" 23 24 #ifdef __STDC__ 25 static const float 26 #else 27 static float 28 #endif 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