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Diffstat (limited to 'Build/source/libs/mpfr/mpfr-src/src/exp2.c')
-rw-r--r-- | Build/source/libs/mpfr/mpfr-src/src/exp2.c | 168 |
1 files changed, 0 insertions, 168 deletions
diff --git a/Build/source/libs/mpfr/mpfr-src/src/exp2.c b/Build/source/libs/mpfr/mpfr-src/src/exp2.c deleted file mode 100644 index 087275839c9..00000000000 --- a/Build/source/libs/mpfr/mpfr-src/src/exp2.c +++ /dev/null @@ -1,168 +0,0 @@ -/* mpfr_exp2 -- power of 2 function 2^y - -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 y = 2^z is done by * - * y = exp(z*log(2)). The result is exact iff z is an integer. */ - -int -mpfr_exp2 (mpfr_ptr y, mpfr_srcptr x, mpfr_rnd_t rnd_mode) -{ - int inexact, inex2; - long xint; - mpfr_t xfrac; - MPFR_SAVE_EXPO_DECL (expo); - - MPFR_LOG_FUNC - (("x[%Pu]=%.*Rg rnd=%d", mpfr_get_prec(x), mpfr_log_prec, x, rnd_mode), - ("y[%Pu]=%.*Rg inexact=%d", mpfr_get_prec(y), mpfr_log_prec, y, - inexact)); - - if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (x))) - { - if (MPFR_IS_NAN (x)) - { - MPFR_SET_NAN (y); - MPFR_RET_NAN; - } - else if (MPFR_IS_INF (x)) - { - if (MPFR_IS_POS (x)) - MPFR_SET_INF (y); - else - MPFR_SET_ZERO (y); - MPFR_SET_POS (y); - MPFR_RET (0); - } - else /* 2^0 = 1 */ - { - MPFR_ASSERTD (MPFR_IS_ZERO(x)); - return mpfr_set_ui (y, 1, rnd_mode); - } - } - - /* Since the smallest representable non-zero float is 1/2 * 2^emin, - if x <= emin - 2, the result is either 1/2 * 2^emin or 0. - Warning, for emin - 2 < x < emin - 1, we cannot conclude, since 2^x - might round to 2^(emin - 1) for rounding away or to nearest, and there - might be no underflow, since we consider underflow "after rounding". */ - - MPFR_STAT_STATIC_ASSERT (MPFR_EMIN_MIN >= LONG_MIN + 2); - if (MPFR_UNLIKELY (mpfr_cmp_si (x, __gmpfr_emin - 2) <= 0)) - return mpfr_underflow (y, rnd_mode == MPFR_RNDN ? MPFR_RNDZ : rnd_mode, 1); - - MPFR_STAT_STATIC_ASSERT (MPFR_EMAX_MAX <= LONG_MAX); - if (MPFR_UNLIKELY (mpfr_cmp_si (x, __gmpfr_emax) >= 0)) - return mpfr_overflow (y, rnd_mode, 1); - - /* We now know that emin - 2 < x < emax. Note that an underflow or - overflow is still possible (we have eliminated only easy cases). */ - - MPFR_SAVE_EXPO_MARK (expo); - - /* 2^x = 1 + x*log(2) + O(x^2) for x near zero, and for |x| <= 1 we have - |2^x - 1| <= x < 2^EXP(x). If x > 0 we must round away from 0 (dir=1); - if x < 0 we must round toward 0 (dir=0). */ - MPFR_SMALL_INPUT_AFTER_SAVE_EXPO (y, __gmpfr_one, - MPFR_GET_EXP (x), 0, - MPFR_IS_POS (x), rnd_mode, expo, {}); - - xint = mpfr_get_si (x, MPFR_RNDZ); - mpfr_init2 (xfrac, MPFR_PREC (x)); - MPFR_DBGRES (inexact = mpfr_sub_si (xfrac, x, xint, MPFR_RNDN)); - MPFR_ASSERTD (inexact == 0); - - if (MPFR_IS_ZERO (xfrac)) - { - /* Here, emin - 1 <= x <= emax - 1, so that an underflow or overflow - will not be possible. */ - mpfr_set_ui (y, 1, MPFR_RNDN); - inexact = 0; - } - else - { - /* Declaration of the intermediary variable */ - mpfr_t t; - - /* Declaration of the size variable */ - mpfr_prec_t Ny = MPFR_PREC(y); /* 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 + 5 + MPFR_INT_CEIL_LOG2 (Ny); - - /* initialize of intermediary variable */ - mpfr_init2 (t, Nt); - - /* First computation */ - MPFR_ZIV_INIT (loop, Nt); - for (;;) - { - /* compute exp(x*ln(2))*/ - mpfr_const_log2 (t, MPFR_RNDU); /* ln(2) */ - mpfr_mul (t, xfrac, t, MPFR_RNDU); /* xfrac * ln(2) */ - err = Nt - (MPFR_GET_EXP (t) + 2); /* Estimate of the error */ - mpfr_exp (t, t, MPFR_RNDN); /* exp(xfrac * ln(2)) */ - - if (MPFR_LIKELY (MPFR_CAN_ROUND (t, err, Ny, rnd_mode))) - break; - - /* Actualisation of the precision */ - MPFR_ZIV_NEXT (loop, Nt); - mpfr_set_prec (t, Nt); - } - MPFR_ZIV_FREE (loop); - - inexact = mpfr_set (y, t, rnd_mode); - - mpfr_clear (t); - } - - mpfr_clear (xfrac); - - if (MPFR_UNLIKELY (rnd_mode == MPFR_RNDN && xint == __gmpfr_emin - 1 && - MPFR_GET_EXP (y) == 0 && mpfr_powerof2_raw (y))) - { - /* y was rounded down to 1/2 and the rounded value with an unbounded - exponent range would be 2^(emin-2), i.e. the midpoint between 0 - and the smallest positive FP number. This is a double rounding - problem: we should not round to 0, but to (1/2) * 2^emin. */ - MPFR_SET_EXP (y, __gmpfr_emin); - inexact = 1; - MPFR_SAVE_EXPO_UPDATE_FLAGS (expo, MPFR_FLAGS_UNDERFLOW); - } - else - { - MPFR_CLEAR_FLAGS (); - inex2 = mpfr_mul_2si (y, y, xint, rnd_mode); - if (inex2 != 0) /* underflow or overflow */ - inexact = inex2; - MPFR_SAVE_EXPO_UPDATE_FLAGS (expo, __gmpfr_flags); - } - - MPFR_SAVE_EXPO_FREE (expo); - return mpfr_check_range (y, inexact, rnd_mode); -} |