diff options
Diffstat (limited to 'Build/source/libs/mpfr/mpfr-3.1.2/src/gen_inverse.h')
-rw-r--r-- | Build/source/libs/mpfr/mpfr-3.1.2/src/gen_inverse.h | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/Build/source/libs/mpfr/mpfr-3.1.2/src/gen_inverse.h b/Build/source/libs/mpfr/mpfr-3.1.2/src/gen_inverse.h new file mode 100644 index 00000000000..49f8ed0d758 --- /dev/null +++ b/Build/source/libs/mpfr/mpfr-3.1.2/src/gen_inverse.h @@ -0,0 +1,106 @@ +/* generic inverse of a function. + +Copyright 2005, 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" + +#ifndef ACTION_SPECIAL +#define ACTION_SPECIAL +#endif + +#ifndef ACTION_TINY +#define ACTION_TINY +#endif + +/* example of use: +#define FUNCTION mpfr_sec +#define INVERSE mpfr_cos +#define ACTION_NAN(y) do { MPFR_SET_NAN(y); MPFR_RET_NAN; } while (1) +#define ACTION_INF(y) do { MPFR_SET_NAN(y); MPFR_RET_NAN; } while (1) +#define ACTION_ZERO(y) return mpfr_set_ui (y, 1, MPFR_RNDN) +#include "gen_inverse.h" +*/ + +int +FUNCTION (mpfr_ptr y, mpfr_srcptr x, mpfr_rnd_t rnd_mode) +{ + mpfr_prec_t precy; /* target precision */ + mpfr_prec_t m; /* working precision */ + mpfr_t z; /* temporary variable to store INVERSE(x) */ + int inexact; /* inexact flag */ + MPFR_ZIV_DECL (loop); + MPFR_SAVE_EXPO_DECL (expo); + + if (MPFR_UNLIKELY(MPFR_IS_SINGULAR(x))) + { + if (MPFR_IS_NAN(x)) + ACTION_NAN(y); + else if (MPFR_IS_INF(x)) + ACTION_INF(y); + else /* x = 0 */ + ACTION_ZERO(y,x); + } + + /* x is neither NaN, Inf nor zero */ + MPFR_SAVE_EXPO_MARK (expo); + ACTION_TINY (y, x, rnd_mode); /* special case for very small input x */ + precy = MPFR_PREC(y); + m = precy + MPFR_INT_CEIL_LOG2 (precy) + 3; + mpfr_init2 (z, m); + + MPFR_ZIV_INIT (loop, m); + for(;;) + { + MPFR_BLOCK_DECL (flags); + + MPFR_BLOCK (flags, INVERSE (z, x, MPFR_RNDZ)); /* error k_u < 1 ulp */ + /* FIXME: the following assumes that if an overflow happens with + MPFR_EMAX_MAX, then necessarily an underflow happens with + __gmpfr_emin */ + if (MPFR_OVERFLOW (flags)) + { + int s = MPFR_SIGN(z); + MPFR_ZIV_FREE (loop); + mpfr_clear (z); + MPFR_SAVE_EXPO_FREE (expo); + return mpfr_underflow (y, (rnd_mode == MPFR_RNDN) ? + MPFR_RNDZ : rnd_mode, s); + } + mpfr_ui_div (z, 1, z, MPFR_RNDN); + /* the error is less than c_w + 2*c_u*k_u (see algorithms.tex), + where c_w = 1/2, c_u = 1 since z was rounded toward zero, + thus 1/2 + 2 < 4 */ + if (MPFR_LIKELY (MPFR_CAN_ROUND (z, m - 2, precy, rnd_mode))) + break; + ACTION_SPECIAL; + MPFR_ZIV_NEXT (loop, m); + mpfr_set_prec (z, m); + } + MPFR_ZIV_FREE (loop); + + inexact = mpfr_set (y, z, rnd_mode); + mpfr_clear (z); + + end: + MPFR_SAVE_EXPO_FREE (expo); + return mpfr_check_range (y, inexact, rnd_mode); +} |