From db3a0f1435efcb4461005cb8d8509bff01f9b018 Mon Sep 17 00:00:00 2001 From: das Date: Wed, 12 Mar 2003 20:18:32 +0000 Subject: Initial import of David Gay's gdtoa library for conversion between strings and floating point. --- contrib/gdtoa/ulp.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 contrib/gdtoa/ulp.c (limited to 'contrib/gdtoa/ulp.c') diff --git a/contrib/gdtoa/ulp.c b/contrib/gdtoa/ulp.c new file mode 100644 index 0000000..536994a --- /dev/null +++ b/contrib/gdtoa/ulp.c @@ -0,0 +1,76 @@ +/**************************************************************** + +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 + Bell Laboratories, Room 2C-463 + 600 Mountain Avenue + Murray Hill, NJ 07974-0636 + U.S.A. + dmg@bell-labs.com + */ + +#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) = L; + word1(a) = 0; +#ifndef Sudden_Underflow + } + else { + L = -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; + } -- cgit v1.1