1 /* $NetBSD: ulp.c,v 1.2 2006/01/25 15:27:42 kleink Exp $ */ 2 3 /**************************************************************** 4 5 The author of this software is David M. Gay. 6 7 Copyright (C) 1998, 1999 by Lucent Technologies 8 All Rights Reserved 9 10 Permission to use, copy, modify, and distribute this software and 11 its documentation for any purpose and without fee is hereby 12 granted, provided that the above copyright notice appear in all 13 copies and that both that the copyright notice and this 14 permission notice and warranty disclaimer appear in supporting 15 documentation, and that the name of Lucent or any of its entities 16 not be used in advertising or publicity pertaining to 17 distribution of the software without specific, written prior 18 permission. 19 20 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 21 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. 22 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY 23 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 24 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER 25 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, 26 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF 27 THIS 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 #include <LibConfig.h> 34 35 #include "gdtoaimp.h" 36 37 double 38 ulp 39 #ifdef KR_headers 40 (x) double x; 41 #else 42 (double x) 43 #endif 44 { 45 Long L; 46 double a; 47 48 L = (word0(x) & Exp_mask) - (P-1)*Exp_msk1; 49 #ifndef Sudden_Underflow 50 if (L > 0) { 51 #endif 52 #ifdef IBM 53 L |= Exp_msk1 >> 4; 54 #endif 55 word0(a) = (UINT32)L; 56 word1(a) = 0; 57 #ifndef Sudden_Underflow 58 } 59 else { 60 L = (unsigned int)-L >> Exp_shift; 61 if (L < Exp_shift) { 62 word0(a) = 0x80000 >> L; 63 word1(a) = 0; 64 } 65 else { 66 word0(a) = 0; 67 L -= Exp_shift; 68 word1(a) = L >= 31 ? 1 : 1 << (31 - L); 69 } 70 } 71 #endif 72 return a; 73 } 74
