text: /* --------------------------------------------------------------  */
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  /* PROLOG END TAG zYx                                              */
  #ifdef __SPU__
  
  #ifndef _COSF4_H_
  #define _COSF4_H_	1
  
  
  #include <spu_intrinsics.h>
  
  #include "cos_sin.h"
  
  /*
   * FUNCTION
   *	vector float _cosf4(vector float angle)
   *
   * DESCRIPTION
   *	The _cosf4 function computes the cosine of a vector of angles 
   *      (expressed in radians) to an accuracy of single precision floating
   *       point.
   *
   */
  static __inline vector float _cosf4(vector float angle)
  {
    vec_int4   octant;
    vec_uint4  select;
    vec_float4 cos, sin;
    vec_float4 toggle_sign, answer;
  
    /* Range reduce the input angle x into the range -PI/4 to PI/4
     * by performing simple modulus.
     */
    MOD_PI_OVER_FOUR_F(angle, octant);
  
    /* Compute the cosine and sine of the range reduced input.
     */
    COMPUTE_COS_SIN_F(angle, cos, sin);
  
    /* For each SIMD element, select which result (cos or sin) to use
     * with a sign correction depending upon the octant of the original
     * angle (Maclaurin series).
     *
     *   octants      angles     select  sign toggle 
     *   -------   ------------  ------  -----------
     *     0          0 to 45     cos        no      
     *    1,2        45 to 135    sin        yes
     *    3,4       135 to 225    cos        yes
     *    5,6       225 to 315    sin        no
     *     7        315 to 360    cos        no
     */ 
    toggle_sign = (vec_float4)spu_sl(spu_and(spu_add(octant, 2), 4), 29);
    select = spu_cmpeq(spu_and(octant, 2), 0);
  
    answer = spu_xor(spu_sel(sin, cos, select), toggle_sign);
  
    return (answer);
  
  }
  
  #endif /* _COSF4_H_ */
  #endif /* __SPU__ */
  