compiler/stdc/math/k_sincos.h

   1 /*-
   2  * ====================================================
   3  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   4  *
   5  * Developed at SunSoft, a Sun Microsystems, Inc. business.
   6  * Permission to use, copy, modify, and distribute this
   7  * software is freely granted, provided that this notice
   8  * is preserved.
   9  * ====================================================
  10  *
  11  * k_sin.c and k_cos.c merged by Steven G. Kargl.
  12  */
  13
  14 //__FBSDID("$FreeBSD$");
  15
  16 static const double
  17 S1  = -1.66666666666666324348e-01, /* 0xBFC55555, 0x55555549 */
  18 S2  =  8.33333333332248946124e-03, /* 0x3F811111, 0x1110F8A6 */
  19 S3  = -1.98412698298579493134e-04, /* 0xBF2A01A0, 0x19C161D5 */
  20 S4  =  2.75573137070700676789e-06, /* 0x3EC71DE3, 0x57B1FE7D */
  21 S5  = -2.50507602534068634195e-08, /* 0xBE5AE5E6, 0x8A2B9CEB */
  22 S6  =  1.58969099521155010221e-10; /* 0x3DE5D93A, 0x5ACFD57C */
  23
  24 static const double
  25 C1  =  4.16666666666666019037e-02, /* 0x3FA55555, 0x5555554C */
  26 C2  = -1.38888888888741095749e-03, /* 0xBF56C16C, 0x16C15177 */
  27 C3  =  2.48015872894767294178e-05, /* 0x3EFA01A0, 0x19CB1590 */
  28 C4  = -2.75573143513906633035e-07, /* 0xBE927E4F, 0x809C52AD */
  29 C5  =  2.08757232129817482790e-09, /* 0x3E21EE9E, 0xBDB4B1C4 */
  30 C6  = -1.13596475577881948265e-11; /* 0xBDA8FAE9, 0xBE8838D4 */
  31
  32 static inline void
  33 __kernel_sincos(double x, double y, int iy, double *sn, double *cs)
  34 {
  35         double hz, r, v, w, z;
  36
  37         z = x * x;
  38         w = z * z;
  39         r = S2 + z * (S3 + z * S4) + z * w * (S5 + z * S6);
  40         v = z * x;
  41
  42         if (iy == 0)
  43                 *sn = x + v * (S1 + z * r);
  44         else
  45                 *sn = x - ((z * (y / 2 - v * r) - y) - v * S1);
  46
  47         r = z * (C1 + z * (C2 + z * C3)) + w * w * (C4 + z * (C5 + z * C6));
  48         hz = z / 2;
  49         w = 1 - hz;
  50         *cs = w + (((1 - w) - hz) + (z * r - x * y));
  51 }