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glibc  2.9
s_sincosl.c
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00001 /* Compute sine and cosine of argument.
00002    Copyright (C) 1997, 1999 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and
00005                 Jakub Jelinek <jj@ultra.linux.cz>.
00006 
00007    The GNU C Library is free software; you can redistribute it and/or
00008    modify it under the terms of the GNU Lesser General Public
00009    License as published by the Free Software Foundation; either
00010    version 2.1 of the License, or (at your option) any later version.
00011 
00012    The GNU C Library is distributed in the hope that it will be useful,
00013    but WITHOUT ANY WARRANTY; without even the implied warranty of
00014    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015    Lesser General Public License for more details.
00016 
00017    You should have received a copy of the GNU Lesser General Public
00018    License along with the GNU C Library; if not, write to the Free
00019    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00020    02111-1307 USA.  */
00021 
00022 #include <math.h>
00023 
00024 #include "math_private.h"
00025 
00026 void
00027 __sincosl (long double x, long double *sinx, long double *cosx)
00028 {
00029   int64_t ix;
00030 
00031   /* High word of x. */
00032   GET_LDOUBLE_MSW64 (ix, x);
00033 
00034   /* |x| ~< pi/4 */
00035   ix &= 0x7fffffffffffffffLL;
00036   if (ix <= 0x3ffe921fb54442d1LL)
00037     __kernel_sincosl (x, 0.0L, sinx, cosx, 0);
00038   else if (ix >= 0x7fff000000000000LL)
00039     {
00040       /* sin(Inf or NaN) is NaN */
00041       *sinx = *cosx = x - x;
00042     }
00043   else
00044     {
00045       /* Argument reduction needed.  */
00046       long double y[2];
00047       int n;
00048 
00049       n = __ieee754_rem_pio2l (x, y);
00050       switch (n & 3)
00051        {
00052        case 0:
00053          __kernel_sincosl (y[0], y[1], sinx, cosx, 1);
00054          break;
00055        case 1:
00056          __kernel_sincosl (y[0], y[1], cosx, sinx, 1);
00057          *cosx = -*cosx;
00058          break;
00059        case 2:
00060          __kernel_sincosl (y[0], y[1], sinx, cosx, 1);
00061          *sinx = -*sinx;
00062          *cosx = -*cosx;
00063          break;
00064        default:
00065          __kernel_sincosl (y[0], y[1], cosx, sinx, 1);
00066          *sinx = -*sinx;
00067          break;
00068        }
00069     }
00070 }
00071 weak_alias (__sincosl, sincosl)