1 /* $NetBSD: s_frexpl.c,v 1.3 2013/02/12 21:40:19 martin Exp $ */ 2 3 /*- 4 * Copyright (c) 2004-2005 David Schultz <das@FreeBSD.ORG> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD: src/lib/msun/src/s_frexpl.c,v 1.1 2005/03/07 04:54:51 das Exp $ 29 */ 30 31 #include <sys/cdefs.h> 32 __RCSID("$NetBSD: s_frexpl.c,v 1.3 2013/02/12 21:40:19 martin Exp $"); 33 34 #include <machine/ieee.h> 35 #include <float.h> 36 #include <math.h> 37 38 #include "math_private.h" 39 40 #ifdef __HAVE_LONG_DOUBLE 41 #if LDBL_MAX_EXP != 0x4000 42 #error "Unsupported long double format" 43 #endif 44 45 long double 46 frexpl(long double x, int *ex) 47 { 48 union ieee_ext_u u; 49 50 u.extu_ld = x; 51 switch (u.extu_ext.ext_exp) { 52 case 0: /* 0 or subnormal */ 53 if ((u.extu_ext.ext_fracl | u.extu_ext.ext_frach) == 0) { 54 *ex = 0; 55 } else { 56 u.extu_ld *= 0x1.0p514; 57 *ex = u.extu_ext.ext_exp - 0x4200; 58 u.extu_ext.ext_exp = 0x3ffe; 59 } 60 break; 61 case 0x7fff: /* infinity or NaN; value of *ex is unspecified */ 62 break; 63 default: /* normal */ 64 *ex = u.extu_ext.ext_exp - 0x3ffe; 65 u.extu_ext.ext_exp = 0x3ffe; 66 break; 67 } 68 return (u.extu_ld); 69 } 70 #endif 71