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Diffstat (limited to 'Build/source/libs/mpfr/mpfr-3.1.2/src/fits_intmax.c')
-rw-r--r-- | Build/source/libs/mpfr/mpfr-3.1.2/src/fits_intmax.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/Build/source/libs/mpfr/mpfr-3.1.2/src/fits_intmax.c b/Build/source/libs/mpfr/mpfr-3.1.2/src/fits_intmax.c new file mode 100644 index 00000000000..260338eb63e --- /dev/null +++ b/Build/source/libs/mpfr/mpfr-3.1.2/src/fits_intmax.c @@ -0,0 +1,107 @@ +/* mpfr_fits_intmax_p -- test whether an mpfr fits an intmax_t. + +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. */ + +#ifdef HAVE_CONFIG_H +# include "config.h" /* for a build within gmp */ +#endif + +#include "mpfr-intmax.h" +#include "mpfr-impl.h" + +#ifdef _MPFR_H_HAVE_INTMAX_T + +/* We can't use fits_s.h <= mpfr_cmp_ui */ +int +mpfr_fits_intmax_p (mpfr_srcptr f, mpfr_rnd_t rnd) +{ + mpfr_exp_t e; + int prec; + mpfr_t x, y; + int neg; + int res; + + if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (f))) + /* Zero always fit */ + return MPFR_IS_ZERO (f) ? 1 : 0; + + /* now it fits if either + (a) MINIMUM <= f <= MAXIMUM + (b) or MINIMUM <= round(f, prec(slong), rnd) <= MAXIMUM */ + + e = MPFR_EXP (f); + if (e < 1) + return 1; /* |f| < 1: always fits */ + + neg = MPFR_IS_NEG (f); + + /* let EXTREMUM be MAXIMUM if f > 0, and MINIMUM if f < 0 */ + + /* first compute prec(EXTREMUM), this could be done at configure time, + but the result can depend on neg (the loop is moved inside the "if" + to give the compiler a better chance to compute prec statically) */ + if (neg) + { + uintmax_t s; + /* In C89, the division on negative integers isn't well-defined. */ + s = SAFE_ABS (uintmax_t, MPFR_INTMAX_MIN); + for (prec = 0; s != 0; s /= 2, prec ++); + } + else + { + intmax_t s; + s = MPFR_INTMAX_MAX; + for (prec = 0; s != 0; s /= 2, prec ++); + } + + /* EXTREMUM needs prec bits, i.e. 2^(prec-1) <= |EXTREMUM| < 2^prec */ + + /* if e <= prec - 1, then f < 2^(prec-1) <= |EXTREMUM| */ + if (e <= prec - 1) + return 1; + + /* if e >= prec + 1, then f >= 2^prec > |EXTREMUM| */ + if (e >= prec + 1) + return 0; + + MPFR_ASSERTD (e == prec); + + /* hard case: first round to prec bits, then check */ + mpfr_init2 (x, prec); + mpfr_set (x, f, rnd); + + if (neg) + { + mpfr_init2 (y, prec); + mpfr_set_sj (y, MPFR_INTMAX_MIN, MPFR_RNDN); + res = mpfr_cmp (x, y) >= 0; + mpfr_clear (y); + } + else + { + res = MPFR_GET_EXP (x) == e; + } + + mpfr_clear (x); + return res; +} + +#endif |