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73a68f94d6
This patch fixes some sinf/cosf calculations that generated unexpected underflows exceptions.
54 lines
1.7 KiB
C
54 lines
1.7 KiB
C
/* k_sinf.c -- float version of k_sin.c
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Copyright (C) 2011 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Adhemerval Zanella <azanella@br.ibm.com>, 2011
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, see <http://www.gnu.org/licenses/>. */
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#include <math.h>
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#include <fenv.h>
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#include <math_private.h>
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static const float twom27 = 7.4505806000e-09;
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static const float half = 5.0000000000e-01;
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static const float S1 = -1.6666667163e-01;
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static const float S2 = 8.3333337680e-03;
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static const float S3 = -1.9841270114e-04;
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static const float S4 = 2.7557314297e-06;
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static const float S5 = -2.5050759689e-08;
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static const float S6 = 1.5896910177e-10;
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float
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__kernel_sinf (float x, float y, int iy)
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{
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float z, r, v;
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float ix;
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ix = __builtin_fabsf (x);
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if (ix < twom27)
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{ /* |x| < 2**-27 */
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__feraiseexcept (FE_INEXACT);
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return x;
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}
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z = x * x;
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v = z * x;
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r = S2 + z * (S3 + z * (S4 + z * (S5 + z * S6)));
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if (iy == 0)
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return x + v * (S1 + z * r);
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else
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return x - ((z * (half * y - v * r) - y) - v * S1);
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}
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