| /* $NetBSD: ulp.c,v 1.2 2006/01/25 15:27:42 kleink Exp $ */ | |
| /**************************************************************** | |
| The author of this software is David M. Gay. | |
| Copyright (C) 1998, 1999 by Lucent Technologies | |
| All Rights Reserved | |
| Permission to use, copy, modify, and distribute this software and | |
| its documentation for any purpose and without fee is hereby | |
| granted, provided that the above copyright notice appear in all | |
| copies and that both that the copyright notice and this | |
| permission notice and warranty disclaimer appear in supporting | |
| documentation, and that the name of Lucent or any of its entities | |
| not be used in advertising or publicity pertaining to | |
| distribution of the software without specific, written prior | |
| permission. | |
| LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, | |
| INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. | |
| IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY | |
| SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | |
| WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER | |
| IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, | |
| ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF | |
| THIS SOFTWARE. | |
| ****************************************************************/ | |
| /* Please send bug reports to David M. Gay (dmg at acm dot org, | |
| * with " at " changed at "@" and " dot " changed to "."). */ | |
| #include <LibConfig.h> | |
| #include "gdtoaimp.h" | |
| double | |
| ulp | |
| #ifdef KR_headers | |
| (x) double x; | |
| #else | |
| (double x) | |
| #endif | |
| { | |
| Long L; | |
| double a; | |
| L = (word0(x) & Exp_mask) - (P-1)*Exp_msk1; | |
| #ifndef Sudden_Underflow | |
| if (L > 0) { | |
| #endif | |
| #ifdef IBM | |
| L |= Exp_msk1 >> 4; | |
| #endif | |
| word0(a) = (UINT32)L; | |
| word1(a) = 0; | |
| #ifndef Sudden_Underflow | |
| } | |
| else { | |
| L = (unsigned int)-L >> Exp_shift; | |
| if (L < Exp_shift) { | |
| word0(a) = 0x80000 >> L; | |
| word1(a) = 0; | |
| } | |
| else { | |
| word0(a) = 0; | |
| L -= Exp_shift; | |
| word1(a) = L >= 31 ? 1 : 1 << (31 - L); | |
| } | |
| } | |
| #endif | |
| return a; | |
| } |