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Diff for /src/lib/libm/src/k_sin.c between version 1.9 and 1.10

version 1.9, 1997/10/09 11:30:24 version 1.10, 1999/07/02 15:37:41
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Line 5 
  *   *
  * Developed at SunPro, a Sun Microsystems, Inc. business.   * Developed at SunPro, a Sun Microsystems, Inc. business.
  * Permission to use, copy, modify, and distribute this   * Permission to use, copy, modify, and distribute this
  * software is freely granted, provided that this notice   * software is freely granted, provided that this notice
  * is preserved.   * is preserved.
  * ====================================================   * ====================================================
  */   */
Line 19  __RCSID("$NetBSD$");
Line 19  __RCSID("$NetBSD$");
  * kernel sin function on [-pi/4, pi/4], pi/4 ~ 0.7854   * kernel sin function on [-pi/4, pi/4], pi/4 ~ 0.7854
  * Input x is assumed to be bounded by ~pi/4 in magnitude.   * Input x is assumed to be bounded by ~pi/4 in magnitude.
  * Input y is the tail of x.   * Input y is the tail of x.
  * Input iy indicates whether y is 0. (if iy=0, y assume to be 0).   * Input iy indicates whether y is 0. (if iy=0, y assume to be 0).
  *   *
  * Algorithm   * Algorithm
  *      1. Since sin(-x) = -sin(x), we need only to consider positive x.   *      1. Since sin(-x) = -sin(x), we need only to consider positive x.
  *      2. if x < 2^-27 (hx<0x3e400000 0), return x with inexact if x!=0.   *      2. if x < 2^-27 (hx<0x3e400000 0), return x with inexact if x!=0.
  *      3. sin(x) is approximated by a polynomial of degree 13 on   *      3. sin(x) is approximated by a polynomial of degree 13 on
  *         [0,pi/4]   *         [0,pi/4]
  *                               3            13   *                               3            13
  *              sin(x) ~ x + S1*x + ... + S6*x   *              sin(x) ~ x + S1*x + ... + S6*x
  *         where   *         where
  *   *
  *      |sin(x)         2     4     6     8     10     12  |     -58   *      |sin(x)         2     4     6     8     10     12  |     -58
  *      |----- - (1+S1*x +S2*x +S3*x +S4*x +S5*x  +S6*x   )| <= 2   *      |----- - (1+S1*x +S2*x +S3*x +S4*x +S5*x  +S6*x   )| <= 2
  *      |  x                                               |   *      |  x                                               |
  *   *
  *      4. sin(x+y) = sin(x) + sin'(x')*y   *      4. sin(x+y) = sin(x) + sin'(x')*y
  *                  ~ sin(x) + (1-x*x/2)*y   *                  ~ sin(x) + (1-x*x/2)*y
  *         For better accuracy, let   *         For better accuracy, let
  *                   3      2      2      2      2   *                   3      2      2      2      2
  *              r = x *(S2+x *(S3+x *(S4+x *(S5+x *S6))))   *              r = x *(S2+x *(S3+x *(S4+x *(S5+x *S6))))
  *         then                   3    2   *         then                   3    2
Line 47  __RCSID("$NetBSD$");
Line 47  __RCSID("$NetBSD$");
 #include "math_private.h"  #include "math_private.h"
   
 #ifdef __STDC__  #ifdef __STDC__
 static const double  static const double
 #else  #else
 static double  static double
 #endif  #endif
 half =  5.00000000000000000000e-01, /* 0x3FE00000, 0x00000000 */  half =  5.00000000000000000000e-01, /* 0x3FE00000, 0x00000000 */
 S1  = -1.66666666666666324348e-01, /* 0xBFC55555, 0x55555549 */  S1  = -1.66666666666666324348e-01, /* 0xBFC55555, 0x55555549 */
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