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e88ecbbfe8
Refactor the sincos implementation - rather than rely on odd partial inlining of preprocessed portions from sin and cos, explicitly write out the cases. This makes sincos much easier to maintain and provides an additional 16-20% speedup between 0 and 2^27. The overall speedup of sincos is 48% over this range. Between 0 and PI it is 66% faster. * sysdeps/ieee754/dbl-64/s_sin.c (__sin): Cleanup ifdefs. (__cos): Likewise. * sysdeps/ieee754/dbl-64/s_sin.c (__sincos): Refactor using the same logic as sin and cos.
103 lines
2.3 KiB
C
103 lines
2.3 KiB
C
/* Compute sine and cosine of argument.
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Copyright (C) 1997-2018 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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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 Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the 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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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <errno.h>
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#include <math.h>
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#include <math_private.h>
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#include <libm-alias-double.h>
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#define IN_SINCOS
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#include "s_sin.c"
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void
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__sincos (double x, double *sinx, double *cosx)
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{
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mynumber u;
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int k;
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SET_RESTORE_ROUND_53BIT (FE_TONEAREST);
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u.x = x;
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k = u.i[HIGH_HALF] & 0x7fffffff;
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if (k < 0x400368fd)
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{
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double a, da, y;
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/* |x| < 2^-27 => cos (x) = 1, sin (x) = x. */
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if (k < 0x3e400000)
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{
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if (k < 0x3e500000)
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math_check_force_underflow (x);
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*sinx = x;
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*cosx = 1.0;
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return;
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}
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/* |x| < 0.855469. */
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else if (k < 0x3feb6000)
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{
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*sinx = do_sin (x, 0);
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*cosx = do_cos (x, 0);
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return;
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}
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/* |x| < 2.426265. */
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y = hp0 - fabs (x);
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a = y + hp1;
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da = (y - a) + hp1;
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*sinx = __copysign (do_cos (a, da), x);
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*cosx = do_sin (a, da);
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return;
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}
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/* |x| < 2^1024. */
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if (k < 0x7ff00000)
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{
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double a, da, xx;
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unsigned int n;
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/* If |x| < 105414350 use simple range reduction. */
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n = k < 0x419921FB ? reduce_sincos (x, &a, &da) : __branred (x, &a, &da);
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n = n & 3;
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if (n == 1 || n == 2)
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{
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a = -a;
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da = -da;
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}
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if (n & 1)
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{
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double *temp = cosx;
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cosx = sinx;
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sinx = temp;
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}
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*sinx = do_sin (a, da);
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xx = do_cos (a, da);
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*cosx = (n & 2) ? -xx : xx;
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return;
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}
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if (isinf (x))
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__set_errno (EDOM);
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*sinx = *cosx = x / x;
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}
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libm_alias_double (__sincos, sincos)
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