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Diffstat (limited to 'Build/source/libs/mpfi/mpfi-src/src/log.c')
-rw-r--r-- | Build/source/libs/mpfi/mpfi-src/src/log.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/Build/source/libs/mpfi/mpfi-src/src/log.c b/Build/source/libs/mpfi/mpfi-src/src/log.c new file mode 100644 index 00000000000..8b07cab2406 --- /dev/null +++ b/Build/source/libs/mpfi/mpfi-src/src/log.c @@ -0,0 +1,53 @@ +/* log.c -- Logarithm of an interval. + +Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2010, + Spaces project, Inria Lorraine + and Salsa project, INRIA Rocquencourt, + and Arenaire project, Inria Rhone-Alpes, France + and Lab. ANO, USTL (Univ. of Lille), France + +This file is part of the MPFI Library. + +The MPFI Library is free software; you can redistribute it and/or modify +it under the terms of the GNU Lesser General Public License as published by +the Free Software Foundation; either version 2.1 of the License, or (at your +option) any later version. + +The MPFI Library 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 Lesser General Public +License for more details. + +You should have received a copy of the GNU Lesser General Public License +along with the MPFI Library; see the file COPYING.LIB. If not, write to +the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, +MA 02110-1301, USA. */ + +#include "mpfi-impl.h" + +/* Computes the log of an interval */ +/* Special cases are handled by mpfr_log */ + +int +mpfi_log (mpfi_ptr a, mpfi_srcptr b) +{ + int inexact_left, inexact_right, inexact=0; + + inexact_left = mpfr_log (&(a->left), &(b->left), MPFI_RNDD); + inexact_right = mpfr_log (&(a->right), &(b->right), MPFI_RNDU); + + /* do not allow +0 as upper bound */ + if (mpfr_zero_p (&(a->right)) && !mpfr_signbit (&(a->right))) { + mpfr_neg (&(a->right), &(a->right), MPFI_RNDD); + } + + if ( MPFI_NAN_P (a) ) + MPFR_RET_NAN; + + if (inexact_left) + inexact += 1; + if (inexact_right) + inexact += 2; + + return inexact; +} |