1/* $NetBSD: ulp.c,v 1.2 2006/01/25 15:27:42 kleink Exp $ */ 2 3/**************************************************************** 4 5The author of this software is David M. Gay. 6 7Copyright (C) 1998, 1999 by Lucent Technologies 8All Rights Reserved 9 10Permission to use, copy, modify, and distribute this software and 11its documentation for any purpose and without fee is hereby 12granted, provided that the above copyright notice appear in all 13copies and that both that the copyright notice and this 14permission notice and warranty disclaimer appear in supporting 15documentation, and that the name of Lucent or any of its entities 16not be used in advertising or publicity pertaining to 17distribution of the software without specific, written prior 18permission. 19 20LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 21INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. 22IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY 23SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 24WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER 25IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, 26ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF 27THIS SOFTWARE. 28 29****************************************************************/ 30 31/* Please send bug reports to David M. Gay (dmg at acm dot org, 32 * with " at " changed at "@" and " dot " changed to "."). */ 33 34#include "gdtoaimp.h" 35 36 double 37ulp 38#ifdef KR_headers 39 (x) U *x; 40#else 41 (U *x) 42#endif 43{ 44 Long L; 45 U a; 46 47 L = (word0(x) & Exp_mask) - (P-1)*Exp_msk1; 48#ifndef Sudden_Underflow 49 if (L > 0) { 50#endif 51#ifdef IBM 52 L |= Exp_msk1 >> 4; 53#endif 54 word0(&a) = L; 55 word1(&a) = 0; 56#ifndef Sudden_Underflow 57 } 58 else { 59 L = (unsigned int)-L >> Exp_shift; 60 if (L < Exp_shift) { 61 word0(&a) = 0x80000 >> L; 62 word1(&a) = 0; 63 } 64 else { 65 word0(&a) = 0; 66 L -= Exp_shift; 67 word1(&a) = L >= 31 ? 1 : 1 << (31 - L); 68 } 69 } 70#endif 71 return dval(&a); 72 } 73