From abbad00edd7f5f3d33ae77a9d5ac338e5bea5fb3 Mon Sep 17 00:00:00 2001 From: Thomas Guyot-Sionnest Date: Tue, 12 Feb 2008 12:03:58 +0000 Subject: Import Gnulib floorf and base64 and removed our old base64 library. git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@1926 f882894a-f735-0410-b71e-b25c423dba1c --- gl/floor.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 gl/floor.c (limited to 'gl/floor.c') diff --git a/gl/floor.c b/gl/floor.c new file mode 100644 index 00000000..05a6591a --- /dev/null +++ b/gl/floor.c @@ -0,0 +1,93 @@ +/* Round towards negative infinity. + Copyright (C) 2007 Free Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +/* Written by Bruno Haible , 2007. */ + +#include + +/* Specification. */ +#include + +#include + +#ifdef USE_LONG_DOUBLE +# define FUNC floorl +# define DOUBLE long double +# define MANT_DIG LDBL_MANT_DIG +# define L_(literal) literal##L +#elif ! defined USE_FLOAT +# define FUNC floor +# define DOUBLE double +# define MANT_DIG DBL_MANT_DIG +# define L_(literal) literal +#else /* defined USE_FLOAT */ +# define FUNC floorf +# define DOUBLE float +# define MANT_DIG FLT_MANT_DIG +# define L_(literal) literal##f +#endif + +/* 2^(MANT_DIG-1). */ +static const DOUBLE TWO_MANT_DIG = + /* Assume MANT_DIG <= 5 * 31. + Use the identity + n = floor(n/5) + floor((n+1)/5) + ... + floor((n+4)/5). */ + (DOUBLE) (1U << ((MANT_DIG - 1) / 5)) + * (DOUBLE) (1U << ((MANT_DIG - 1 + 1) / 5)) + * (DOUBLE) (1U << ((MANT_DIG - 1 + 2) / 5)) + * (DOUBLE) (1U << ((MANT_DIG - 1 + 3) / 5)) + * (DOUBLE) (1U << ((MANT_DIG - 1 + 4) / 5)); + +DOUBLE +FUNC (DOUBLE x) +{ + /* The use of 'volatile' guarantees that excess precision bits are dropped + at each addition step and before the following comparison at the caller's + site. It is necessary on x86 systems where double-floats are not IEEE + compliant by default, to avoid that the results become platform and compiler + option dependent. 'volatile' is a portable alternative to gcc's + -ffloat-store option. */ + volatile DOUBLE y = x; + volatile DOUBLE z = y; + + if (z > L_(0.0)) + { + /* Avoid rounding errors for values near 2^k, where k >= MANT_DIG-1. */ + if (z < TWO_MANT_DIG) + { + /* Round to the next integer (nearest or up or down, doesn't matter). */ + z += TWO_MANT_DIG; + z -= TWO_MANT_DIG; + /* Enforce rounding down. */ + if (z > y) + z -= L_(1.0); + } + } + else if (z < L_(0.0)) + { + /* Avoid rounding errors for values near -2^k, where k >= MANT_DIG-1. */ + if (z > - TWO_MANT_DIG) + { + /* Round to the next integer (nearest or up or down, doesn't matter). */ + z -= TWO_MANT_DIG; + z += TWO_MANT_DIG; + /* Enforce rounding down. */ + if (z > y) + z -= L_(1.0); + } + } + return z; +} -- cgit v1.2.3-74-g34f1