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Diffstat (limited to 'Build/source/libs/mpfr/mpfr-3.1.2/src/set_si_2exp.c')
-rw-r--r-- | Build/source/libs/mpfr/mpfr-3.1.2/src/set_si_2exp.c | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/Build/source/libs/mpfr/mpfr-3.1.2/src/set_si_2exp.c b/Build/source/libs/mpfr/mpfr-3.1.2/src/set_si_2exp.c new file mode 100644 index 00000000000..2064a70db5b --- /dev/null +++ b/Build/source/libs/mpfr/mpfr-3.1.2/src/set_si_2exp.c @@ -0,0 +1,73 @@ +/* mpfr_set_si_2exp -- set a MPFR number from a machine signed integer with + a shift + +Copyright 2004, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 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_set_si_2exp (mpfr_ptr x, long i, mpfr_exp_t e, mpfr_rnd_t rnd_mode) +{ + if (i == 0) + { + MPFR_SET_ZERO (x); + MPFR_SET_POS (x); + MPFR_RET (0); + } + else + { + mp_size_t xn; + unsigned int cnt, nbits; + mp_limb_t ai, *xp; + int inex = 0; + + /* FIXME: support int limbs (e.g. 16-bit limbs on 16-bit proc) */ + ai = SAFE_ABS (unsigned long, i); + MPFR_ASSERTN (SAFE_ABS (unsigned long, i) == ai); + + /* Position of the highest limb */ + xn = (MPFR_PREC (x) - 1) / GMP_NUMB_BITS; + count_leading_zeros (cnt, ai); + MPFR_ASSERTD (cnt < GMP_NUMB_BITS); /* OK since i != 0 */ + + xp = MPFR_MANT(x); + xp[xn] = ai << cnt; + /* Zero the xn lower limbs. */ + MPN_ZERO(xp, xn); + MPFR_SET_SIGN (x, i < 0 ? MPFR_SIGN_NEG : MPFR_SIGN_POS); + + nbits = GMP_NUMB_BITS - cnt; + e += nbits; /* exponent _before_ the rounding */ + + /* round if MPFR_PREC(x) smaller than length of i */ + if (MPFR_UNLIKELY (MPFR_PREC (x) < nbits) && + MPFR_UNLIKELY (mpfr_round_raw (xp + xn, xp + xn, nbits, i < 0, + MPFR_PREC (x), rnd_mode, &inex))) + { + e++; + xp[xn] = MPFR_LIMB_HIGHBIT; + } + + MPFR_EXP (x) = e; + return mpfr_check_range (x, inex, rnd_mode); + } +} |