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Diffstat (limited to 'Build/source/libs/mpfr/mpfr-src/src/next.c')
-rw-r--r-- | Build/source/libs/mpfr/mpfr-src/src/next.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/Build/source/libs/mpfr/mpfr-src/src/next.c b/Build/source/libs/mpfr/mpfr-src/src/next.c new file mode 100644 index 00000000000..f03d3885919 --- /dev/null +++ b/Build/source/libs/mpfr/mpfr-src/src/next.c @@ -0,0 +1,150 @@ +/* mpfr_nextabove, mpfr_nextbelow, mpfr_nexttoward -- next representable +floating-point number + +Copyright 1999, 2001-2015 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. */ + +#include "mpfr-impl.h" + +void +mpfr_nexttozero (mpfr_ptr x) +{ + if (MPFR_UNLIKELY(MPFR_IS_INF(x))) + { + mpfr_setmax (x, __gmpfr_emax); + return; + } + else if (MPFR_UNLIKELY( MPFR_IS_ZERO(x) )) + { + MPFR_CHANGE_SIGN(x); + mpfr_setmin (x, __gmpfr_emin); + } + else + { + mp_size_t xn; + int sh; + mp_limb_t *xp; + + xn = MPFR_LIMB_SIZE (x); + MPFR_UNSIGNED_MINUS_MODULO (sh, MPFR_PREC(x)); + xp = MPFR_MANT(x); + mpn_sub_1 (xp, xp, xn, MPFR_LIMB_ONE << sh); + if (MPFR_UNLIKELY( MPFR_LIMB_MSB(xp[xn-1]) == 0) ) + { /* was an exact power of two: not normalized any more */ + mpfr_exp_t exp = MPFR_EXP (x); + if (MPFR_UNLIKELY(exp == __gmpfr_emin)) + MPFR_SET_ZERO(x); + else + { + mp_size_t i; + MPFR_SET_EXP (x, exp - 1); + xp[0] = MP_LIMB_T_MAX << sh; + for (i = 1; i < xn; i++) + xp[i] = MP_LIMB_T_MAX; + } + } + } +} + +void +mpfr_nexttoinf (mpfr_ptr x) +{ + if (MPFR_UNLIKELY(MPFR_IS_INF(x))) + return; + else if (MPFR_UNLIKELY(MPFR_IS_ZERO(x))) + mpfr_setmin (x, __gmpfr_emin); + else + { + mp_size_t xn; + int sh; + mp_limb_t *xp; + + xn = MPFR_LIMB_SIZE (x); + MPFR_UNSIGNED_MINUS_MODULO (sh, MPFR_PREC(x)); + xp = MPFR_MANT(x); + if (MPFR_UNLIKELY( mpn_add_1 (xp, xp, xn, MPFR_LIMB_ONE << sh)) ) + /* got 1.0000... */ + { + mpfr_exp_t exp = MPFR_EXP (x); + if (MPFR_UNLIKELY(exp == __gmpfr_emax)) + MPFR_SET_INF(x); + else + { + MPFR_SET_EXP (x, exp + 1); + xp[xn-1] = MPFR_LIMB_HIGHBIT; + } + } + } +} + +void +mpfr_nextabove (mpfr_ptr x) +{ + if (MPFR_UNLIKELY(MPFR_IS_NAN(x))) + { + __gmpfr_flags |= MPFR_FLAGS_NAN; + return; + } + if (MPFR_IS_NEG(x)) + mpfr_nexttozero (x); + else + mpfr_nexttoinf (x); +} + +void +mpfr_nextbelow (mpfr_ptr x) +{ + if (MPFR_UNLIKELY(MPFR_IS_NAN(x))) + { + __gmpfr_flags |= MPFR_FLAGS_NAN; + return; + } + + if (MPFR_IS_NEG(x)) + mpfr_nexttoinf (x); + else + mpfr_nexttozero (x); +} + +void +mpfr_nexttoward (mpfr_ptr x, mpfr_srcptr y) +{ + int s; + + if (MPFR_UNLIKELY(MPFR_IS_NAN(x))) + { + __gmpfr_flags |= MPFR_FLAGS_NAN; + return; + } + else if (MPFR_UNLIKELY(MPFR_IS_NAN(x) || MPFR_IS_NAN(y))) + { + MPFR_SET_NAN(x); + __gmpfr_flags |= MPFR_FLAGS_NAN; + return; + } + + s = mpfr_cmp (x, y); + if (s == 0) + return; + else if (s < 0) + mpfr_nextabove (x); + else + mpfr_nextbelow (x); +} |