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Diffstat (limited to 'Build/source/libs/mpfi/mpfi-src/src/sqr.c')
-rw-r--r-- | Build/source/libs/mpfi/mpfi-src/src/sqr.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/Build/source/libs/mpfi/mpfi-src/src/sqr.c b/Build/source/libs/mpfi/mpfi-src/src/sqr.c new file mode 100644 index 00000000000..328b1ca813f --- /dev/null +++ b/Build/source/libs/mpfi/mpfi-src/src/sqr.c @@ -0,0 +1,79 @@ +/* sqr.c -- Square 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" + +int +mpfi_sqr (mpfi_ptr a, mpfi_srcptr u) +{ + mpfr_t tmp; + int inexact_left, inexact_right, inexact=0; + + if ( MPFI_NAN_P (u) ) { + mpfr_set_nan (&(a->left)); + mpfr_set_nan (&(a->right)); + MPFR_RET_NAN; + } + if (mpfr_sgn (&(u->left)) >= 0) { + /* u nonnegative */ + inexact_left = mpfr_mul (&(a->left), &(u->left), &(u->left), MPFI_RNDD); + inexact_right = mpfr_mul (&(a->right), &(u->right), &(u->right), MPFI_RNDU); + } + else { + if (mpfr_sgn (&(u->right)) <= 0) { + /* u non-positive -> beware the case where a = u */ + mpfr_init2 (tmp, mpfr_get_prec (&(a->right))); + inexact_right = mpfr_mul (tmp, &(u->left), &(u->left), MPFI_RNDU); + inexact_left = mpfr_mul (&(a->left), &(u->right), &(u->right), MPFI_RNDD); + mpfr_set (&(a->right), tmp, MPFI_RNDU); /* exact */ + mpfr_clear (tmp); + } + else { + /* inf = 0, sup = max of the squares of the endpoints of u */ + if (mpfr_cmp_abs (&(u->left), &(u->right)) <= 0) { + inexact_right = + mpfr_mul (&(a->right), &(u->right), &(u->right), MPFI_RNDU); + } + else { + inexact_right = + mpfr_mul (&(a->right), &(u->left), &(u->left), MPFI_RNDU); + } + inexact_left = mpfr_set_si (&(a->left), (long)0, MPFI_RNDD); + } + } + + /* The NaN case has already been handled */ + if (inexact_left) + inexact += 1; + if (inexact_right) + inexact += 2; + + /* 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); + } + + return inexact; +} |