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Diffstat (limited to 'Build/source/libs/mpfr/mpfr-src/src/log2.c')
-rw-r--r-- | Build/source/libs/mpfr/mpfr-src/src/log2.c | 142 |
1 files changed, 0 insertions, 142 deletions
diff --git a/Build/source/libs/mpfr/mpfr-src/src/log2.c b/Build/source/libs/mpfr/mpfr-src/src/log2.c deleted file mode 100644 index 41cd33c7ee1..00000000000 --- a/Build/source/libs/mpfr/mpfr-src/src/log2.c +++ /dev/null @@ -1,142 +0,0 @@ -/* mpfr_log2 -- log base 2 - -Copyright 2001-2020 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" - - /* The computation of r=log2(a) - r=log2(a)=log(a)/log(2) */ - -int -mpfr_log2 (mpfr_ptr r, mpfr_srcptr a, mpfr_rnd_t rnd_mode) -{ - int inexact; - MPFR_SAVE_EXPO_DECL (expo); - - MPFR_LOG_FUNC - (("a[%Pu]=%.*Rg rnd=%d", mpfr_get_prec (a), mpfr_log_prec, a, rnd_mode), - ("r[%Pu]=%.*Rg inexact=%d", mpfr_get_prec (r), mpfr_log_prec, r, - inexact)); - - if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (a))) - { - /* If a is NaN, the result is NaN */ - if (MPFR_IS_NAN (a)) - { - MPFR_SET_NAN (r); - MPFR_RET_NAN; - } - /* check for infinity before zero */ - else if (MPFR_IS_INF (a)) - { - if (MPFR_IS_NEG (a)) - /* log(-Inf) = NaN */ - { - MPFR_SET_NAN (r); - MPFR_RET_NAN; - } - else /* log(+Inf) = +Inf */ - { - MPFR_SET_INF (r); - MPFR_SET_POS (r); - MPFR_RET (0); - } - } - else /* a is zero */ - { - MPFR_ASSERTD (MPFR_IS_ZERO (a)); - MPFR_SET_INF (r); - MPFR_SET_NEG (r); - MPFR_SET_DIVBY0 (); - MPFR_RET (0); /* log2(0) is an exact -infinity */ - } - } - - /* If a is negative, the result is NaN */ - if (MPFR_UNLIKELY (MPFR_IS_NEG (a))) - { - MPFR_SET_NAN (r); - MPFR_RET_NAN; - } - - /* If a is 1, the result is 0 */ - if (MPFR_UNLIKELY (mpfr_cmp_ui (a, 1) == 0)) - { - MPFR_SET_ZERO (r); - MPFR_SET_POS (r); - MPFR_RET (0); /* only "normal" case where the result is exact */ - } - - /* If a is 2^N, log2(a) is exact*/ - if (MPFR_UNLIKELY (mpfr_cmp_ui_2exp (a, 1, MPFR_GET_EXP (a) - 1) == 0)) - return mpfr_set_si(r, MPFR_GET_EXP (a) - 1, rnd_mode); - - MPFR_SAVE_EXPO_MARK (expo); - - /* General case */ - { - /* Declaration of the intermediary variable */ - mpfr_t t, tt; - /* Declaration of the size variable */ - mpfr_prec_t Ny = MPFR_PREC(r); /* target precision */ - mpfr_prec_t Nt; /* working precision */ - mpfr_exp_t err; /* error */ - MPFR_ZIV_DECL (loop); - - /* compute the precision of intermediary variable */ - /* the optimal number of bits : see algorithms.tex */ - Nt = Ny + 3 + MPFR_INT_CEIL_LOG2 (Ny); - - /* initialize of intermediary variable */ - mpfr_init2 (t, Nt); - mpfr_init2 (tt, Nt); - - /* First computation of log2 */ - MPFR_ZIV_INIT (loop, Nt); - for (;;) - { - /* compute log2 */ - mpfr_const_log2(t,MPFR_RNDD); /* log(2) */ - mpfr_log(tt,a,MPFR_RNDN); /* log(a) */ - mpfr_div(t,tt,t,MPFR_RNDN); /* log(a)/log(2) */ - - /* estimation of the error */ - err = Nt-3; - if (MPFR_LIKELY (MPFR_CAN_ROUND (t, err, Ny, rnd_mode))) - break; - - /* actualization of the precision */ - MPFR_ZIV_NEXT (loop, Nt); - mpfr_set_prec (t, Nt); - mpfr_set_prec (tt, Nt); - } - MPFR_ZIV_FREE (loop); - - inexact = mpfr_set (r, t, rnd_mode); - - mpfr_clear (t); - mpfr_clear (tt); - } - - MPFR_SAVE_EXPO_FREE (expo); - return mpfr_check_range (r, inexact, rnd_mode); -} |