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Diffstat (limited to 'Build/source/libs/mpfr/mpfr-3.1.2/src/tan.c')
-rw-r--r--Build/source/libs/mpfr/mpfr-3.1.2/src/tan.c89
1 files changed, 89 insertions, 0 deletions
diff --git a/Build/source/libs/mpfr/mpfr-3.1.2/src/tan.c b/Build/source/libs/mpfr/mpfr-3.1.2/src/tan.c
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index 00000000000..8cd93cdeff2
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+++ b/Build/source/libs/mpfr/mpfr-3.1.2/src/tan.c
@@ -0,0 +1,89 @@
+/* mpfr_tan -- tangent of a floating-point number
+
+Copyright 2001, 2002, 2003, 2004, 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"
+
+/* computes tan(x) = sign(x)*sqrt(1/cos(x)^2-1) */
+int
+mpfr_tan (mpfr_ptr y, mpfr_srcptr x, mpfr_rnd_t rnd_mode)
+{
+ mpfr_prec_t precy, m;
+ int inexact;
+ mpfr_t s, c;
+ MPFR_ZIV_DECL (loop);
+ MPFR_SAVE_EXPO_DECL (expo);
+ MPFR_GROUP_DECL (group);
+
+ MPFR_LOG_FUNC
+ (("x[%Pu]=%.*Rg rnd=%d", mpfr_get_prec (x), mpfr_log_prec, x, rnd_mode),
+ ("y[%Pu]=%.*Rg inexact=%d",
+ mpfr_get_prec (y), mpfr_log_prec, y, inexact));
+
+ if (MPFR_UNLIKELY(MPFR_IS_SINGULAR(x)))
+ {
+ if (MPFR_IS_NAN(x) || MPFR_IS_INF(x))
+ {
+ MPFR_SET_NAN(y);
+ MPFR_RET_NAN;
+ }
+ else /* x is zero */
+ {
+ MPFR_ASSERTD(MPFR_IS_ZERO(x));
+ MPFR_SET_ZERO(y);
+ MPFR_SET_SAME_SIGN(y, x);
+ MPFR_RET(0);
+ }
+ }
+
+ /* tan(x) = x + x^3/3 + ... so the error is < 2^(3*EXP(x)-1) */
+ MPFR_FAST_COMPUTE_IF_SMALL_INPUT (y, x, -2 * MPFR_GET_EXP (x), 1, 1,
+ rnd_mode, {});
+
+ MPFR_SAVE_EXPO_MARK (expo);
+
+ /* Compute initial precision */
+ precy = MPFR_PREC (y);
+ m = precy + MPFR_INT_CEIL_LOG2 (precy) + 13;
+ MPFR_ASSERTD (m >= 2); /* needed for the error analysis in algorithms.tex */
+
+ MPFR_GROUP_INIT_2 (group, m, s, c);
+ MPFR_ZIV_INIT (loop, m);
+ for (;;)
+ {
+ /* The only way to get an overflow is to get ~ Pi/2
+ But the result will be ~ 2^Prec(y). */
+ mpfr_sin_cos (s, c, x, MPFR_RNDN); /* err <= 1/2 ulp on s and c */
+ mpfr_div (c, s, c, MPFR_RNDN); /* err <= 4 ulps */
+ MPFR_ASSERTD (!MPFR_IS_SINGULAR (c));
+ if (MPFR_LIKELY (MPFR_CAN_ROUND (c, m - 2, precy, rnd_mode)))
+ break;
+ MPFR_ZIV_NEXT (loop, m);
+ MPFR_GROUP_REPREC_2 (group, m, s, c);
+ }
+ MPFR_ZIV_FREE (loop);
+ inexact = mpfr_set (y, c, rnd_mode);
+ MPFR_GROUP_CLEAR (group);
+
+ MPFR_SAVE_EXPO_FREE (expo);
+ return mpfr_check_range (y, inexact, rnd_mode);
+}