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Diffstat (limited to 'Build/source/libs/mpfr/mpfr-src/src/const_pi.c')
-rw-r--r-- | Build/source/libs/mpfr/mpfr-src/src/const_pi.c | 122 |
1 files changed, 0 insertions, 122 deletions
diff --git a/Build/source/libs/mpfr/mpfr-src/src/const_pi.c b/Build/source/libs/mpfr/mpfr-src/src/const_pi.c deleted file mode 100644 index 26c55030d28..00000000000 --- a/Build/source/libs/mpfr/mpfr-src/src/const_pi.c +++ /dev/null @@ -1,122 +0,0 @@ -/* mpfr_const_pi -- compute Pi - -Copyright 1999-2020 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. */ - -#include "mpfr-impl.h" - -/* Declare the cache */ -#ifndef MPFR_USE_LOGGING -MPFR_DECL_INIT_CACHE (__gmpfr_cache_const_pi, mpfr_const_pi_internal) -#else -MPFR_DECL_INIT_CACHE (__gmpfr_normal_pi, mpfr_const_pi_internal) -MPFR_DECL_INIT_CACHE (__gmpfr_logging_pi, mpfr_const_pi_internal) -MPFR_THREAD_VAR (mpfr_cache_ptr, __gmpfr_cache_const_pi, __gmpfr_normal_pi) -#endif - -/* Set User Interface */ -#undef mpfr_const_pi -int -mpfr_const_pi (mpfr_ptr x, mpfr_rnd_t rnd_mode) { - return mpfr_cache (x, __gmpfr_cache_const_pi, rnd_mode); -} - -/* The algorithm used here is taken from Section 8.2.5 of the book - "Fast Algorithms: A Multitape Turing Machine Implementation" - by A. Schönhage, A. F. W. Grotefeld and E. Vetter, 1994. - It is a clever form of Brent-Salamin formula. */ - -/* Don't need to save/restore exponent range: the cache does it */ -int -mpfr_const_pi_internal (mpfr_ptr x, mpfr_rnd_t rnd_mode) -{ - mpfr_t a, A, B, D, S; - mpfr_prec_t px, p, cancel, k, kmax; - MPFR_GROUP_DECL (group); - MPFR_ZIV_DECL (loop); - int inex; - - MPFR_LOG_FUNC - (("rnd_mode=%d", rnd_mode), - ("x[%Pu]=%.*Rg inexact=%d", mpfr_get_prec(x), mpfr_log_prec, x, inex)); - - px = MPFR_PREC (x); - - /* we need 9*2^kmax - 4 >= px+2*kmax+8 */ - for (kmax = 2; ((px + 2 * kmax + 12) / 9) >> kmax; kmax ++); - - p = px + 3 * kmax + 14; /* guarantees no recomputation for px <= 10000 */ - - MPFR_GROUP_INIT_5 (group, p, a, A, B, D, S); - - MPFR_ZIV_INIT (loop, p); - for (;;) { - mpfr_set_ui (a, 1, MPFR_RNDN); /* a = 1 */ - mpfr_set_ui (A, 1, MPFR_RNDN); /* A = a^2 = 1 */ - mpfr_set_ui_2exp (B, 1, -1, MPFR_RNDN); /* B = b^2 = 1/2 */ - mpfr_set_ui_2exp (D, 1, -2, MPFR_RNDN); /* D = 1/4 */ - -#define b B -#define ap a -#define Ap A -#define Bp B - for (k = 0; ; k++) - { - /* invariant: 1/2 <= B <= A <= a < 1 */ - mpfr_add (S, A, B, MPFR_RNDN); /* 1 <= S <= 2 */ - mpfr_div_2ui (S, S, 2, MPFR_RNDN); /* exact, 1/4 <= S <= 1/2 */ - mpfr_sqrt (b, B, MPFR_RNDN); /* 1/2 <= b <= 1 */ - mpfr_add (ap, a, b, MPFR_RNDN); /* 1 <= ap <= 2 */ - mpfr_div_2ui (ap, ap, 1, MPFR_RNDN); /* exact, 1/2 <= ap <= 1 */ - mpfr_sqr (Ap, ap, MPFR_RNDN); /* 1/4 <= Ap <= 1 */ - mpfr_sub (Bp, Ap, S, MPFR_RNDN); /* -1/4 <= Bp <= 3/4 */ - mpfr_mul_2ui (Bp, Bp, 1, MPFR_RNDN); /* -1/2 <= Bp <= 3/2 */ - mpfr_sub (S, Ap, Bp, MPFR_RNDN); - MPFR_ASSERTD (mpfr_cmp_ui (S, 1) < 0); - cancel = MPFR_NOTZERO (S) ? (mpfr_uexp_t) -mpfr_get_exp(S) : p; - /* MPFR_ASSERTN (cancel >= px || cancel >= 9 * (1 << k) - 4); */ - mpfr_mul_2ui (S, S, k, MPFR_RNDN); - mpfr_sub (D, D, S, MPFR_RNDN); - /* stop when |A_k - B_k| <= 2^(k-p) i.e. cancel >= p-k */ - if (cancel >= p - k) - break; - } -#undef b -#undef ap -#undef Ap -#undef Bp - - mpfr_div (A, B, D, MPFR_RNDN); - - /* MPFR_ASSERTN(p >= 2 * k + 8); */ - if (MPFR_LIKELY (MPFR_CAN_ROUND (A, p - 2 * k - 8, px, rnd_mode))) - break; - - p += kmax; - MPFR_ZIV_NEXT (loop, p); - MPFR_GROUP_REPREC_5 (group, p, a, A, B, D, S); - } - MPFR_ZIV_FREE (loop); - inex = mpfr_set (x, A, rnd_mode); - - MPFR_GROUP_CLEAR (group); - - return inex; -} |