1 /* $OpenBSD: s_frexpl.c,v 1.1 2008/12/09 20:00:35 martynas Exp $ */ 2 /*- 3 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD: src/lib/msun/src/s_frexpl.c,v 1.1 2005/03/07 04:54:51 das Exp $ 28 */ 29 30 #include <sys/types.h> 31 #include <machine/ieee.h> 32 #include <float.h> 33 #include <math.h> 34 35 #if LDBL_MAX_EXP != 0x4000 36 #error "Unsupported long double format" 37 #endif 38 39 long double 40 frexpl(long double x, int *ex) 41 { 42 struct ieee_ext *p = (struct ieee_ext *)&x; 43 44 switch (p->ext_exp) { 45 case 0: /* 0 or subnormal */ 46 if ((p->ext_fracl 47 #ifdef EXT_FRACLMBITS 48 | p->ext_fraclm 49 #endif /* EXT_FRACLMBITS */ 50 #ifdef EXT_FRACHMBITS 51 | p->ext_frachm 52 #endif /* EXT_FRACHMBITS */ 53 | p->ext_frach) == 0) { 54 *ex = 0; 55 } else { 56 x *= 0x1.0p514; 57 *ex = p->ext_exp - 0x4200; 58 p->ext_exp = 0x3ffe; 59 } 60 break; 61 case 0x7fff: /* infinity or NaN; value of *ex is unspecified */ 62 break; 63 default: /* normal */ 64 *ex = p->ext_exp - 0x3ffe; 65 p->ext_exp = 0x3ffe; 66 break; 67 } 68 69 return x; 70 } 71