diff options
Diffstat (limited to 'Build/source/libs/mpfr/mpfr-src/src/sub_ui.c')
-rw-r--r-- | Build/source/libs/mpfr/mpfr-src/src/sub_ui.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/Build/source/libs/mpfr/mpfr-src/src/sub_ui.c b/Build/source/libs/mpfr/mpfr-src/src/sub_ui.c new file mode 100644 index 00000000000..798fb1e6fc6 --- /dev/null +++ b/Build/source/libs/mpfr/mpfr-src/src/sub_ui.c @@ -0,0 +1,60 @@ +/* mpfr_sub_ui -- subtract a floating-point number and a machine integer + +Copyright 2000-2015 Free Software Foundation, Inc. +Contributed by the AriC and Caramel projects, INRIA. + +This file is part of the GNU MPFR Library. + +The GNU MPFR 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 3 of the License, or (at your +option) any later version. + +The GNU MPFR 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 GNU MPFR Library; see the file COPYING.LESSER. If not, see +http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., +51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */ + + +#define MPFR_NEED_LONGLONG_H +#include "mpfr-impl.h" + +int +mpfr_sub_ui (mpfr_ptr y, mpfr_srcptr x, unsigned long int u, mpfr_rnd_t rnd_mode) +{ + if (MPFR_LIKELY (u != 0)) /* if u=0, do nothing */ + { + mpfr_t uu; + mp_limb_t up[1]; + unsigned long cnt; + int inex; + + MPFR_SAVE_EXPO_DECL (expo); + + MPFR_LOG_FUNC + (("x[%Pu]=%.*Rg u=%lu rnd=%d", + mpfr_get_prec(x), mpfr_log_prec, x, u, rnd_mode), + ("y[%Pu]=%.*Rg inexact=%d", + mpfr_get_prec(y), mpfr_log_prec, y, inex)); + + MPFR_TMP_INIT1 (up, uu, GMP_NUMB_BITS); + MPFR_ASSERTN (u == (mp_limb_t) u); + count_leading_zeros (cnt, (mp_limb_t) u); + *up = (mp_limb_t) u << cnt; + + /* Optimization note: Exponent save/restore operations may be + removed if mpfr_sub works even when uu is out-of-range. */ + MPFR_SAVE_EXPO_MARK (expo); + MPFR_SET_EXP (uu, GMP_NUMB_BITS - cnt); + inex = mpfr_sub (y, x, uu, rnd_mode); + MPFR_SAVE_EXPO_FREE (expo); + return mpfr_check_range (y, inex, rnd_mode); + } + else + return mpfr_set (y, x, rnd_mode); +} |