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author | Karl Berry <karl@freefriends.org> | 2021-02-25 19:22:25 +0000 |
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committer | Karl Berry <karl@freefriends.org> | 2021-02-25 19:22:25 +0000 |
commit | ad547a6b5986815fda458221149728d9d9ab1d87 (patch) | |
tree | 16296910eb3eca724371474ea9aea3994dc69614 /Build/source/libs/mpfr/mpfr-src/src/ui_sub.c | |
parent | 947b43de3dd21d58ccc2ffadefc4441ea1c2a813 (diff) |
restore Build,TODO from r57911
git-svn-id: svn://tug.org/texlive/trunk@57915 c570f23f-e606-0410-a88d-b1316a301751
Diffstat (limited to 'Build/source/libs/mpfr/mpfr-src/src/ui_sub.c')
-rw-r--r-- | Build/source/libs/mpfr/mpfr-src/src/ui_sub.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/Build/source/libs/mpfr/mpfr-src/src/ui_sub.c b/Build/source/libs/mpfr/mpfr-src/src/ui_sub.c new file mode 100644 index 00000000000..c0b8fadb664 --- /dev/null +++ b/Build/source/libs/mpfr/mpfr-src/src/ui_sub.c @@ -0,0 +1,96 @@ +/* mpfr_ui_sub -- subtract a floating-point number from an integer + +Copyright 2000-2020 Free Software Foundation, Inc. +Contributed by the AriC and Caramba 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 +https://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_ui_sub (mpfr_ptr y, unsigned long int u, mpfr_srcptr x, mpfr_rnd_t rnd_mode) +{ + MPFR_LOG_FUNC + (("u=%lu x[%Pu]=%.*Rg rnd=%d", + u, mpfr_get_prec(x), mpfr_log_prec, x, rnd_mode), + ("y[%Pu]=%.*Rg", mpfr_get_prec(y), mpfr_log_prec, y)); + + /* (unsigned long) 0 is assumed to be a real 0 (unsigned) */ + if (MPFR_UNLIKELY (u == 0)) + return mpfr_neg (y, x, rnd_mode); + + if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (x))) + { + if (MPFR_IS_NAN (x)) + { + MPFR_SET_NAN (y); + MPFR_RET_NAN; + } + if (MPFR_IS_INF (x)) + { + /* u - Inf = -Inf and u - -Inf = +Inf */ + MPFR_SET_INF (y); + MPFR_SET_OPPOSITE_SIGN (y, x); + MPFR_RET (0); /* +/-infinity is exact */ + } + MPFR_ASSERTD (MPFR_IS_ZERO (x) && u != 0); + /* Note: the fact that u != 0 is important due to signed zeros. */ + /* u - 0 = u */ + return mpfr_set_ui (y, u, rnd_mode); + } + + /* Main code */ + { + int inex; + MPFR_SAVE_EXPO_DECL (expo); + + /* 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); + +#ifdef MPFR_LONG_WITHIN_LIMB + { + mpfr_t uu; + mp_limb_t up[1]; + int cnt; + + MPFR_TMP_INIT1 (up, uu, GMP_NUMB_BITS); + /* So, u fits in a mp_limb_t, which justifies the casts below. */ + MPFR_ASSERTD (u != 0); + count_leading_zeros (cnt, (mp_limb_t) u); + up[0] = (mp_limb_t) u << cnt; + MPFR_SET_EXP (uu, GMP_NUMB_BITS - cnt); + inex = mpfr_sub (y, uu, x, rnd_mode); + } +#else + { + mpfr_t uu; + + mpfr_init2 (uu, sizeof (unsigned long) * CHAR_BIT); + mpfr_set_ui (uu, u, MPFR_RNDZ); + inex = mpfr_sub (y, uu, x, rnd_mode); + mpfr_clear (uu); + } +#endif + + MPFR_SAVE_EXPO_UPDATE_FLAGS (expo, __gmpfr_flags); + MPFR_SAVE_EXPO_FREE (expo); + return mpfr_check_range (y, inex, rnd_mode); + } +} |