compiler/stdc/math/sincos.c

   1 /*
   2     Copyright © 1995-2014, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <aros/debug.h>
   7
   8 #include "math.h"
   9 #include "math_private.h"
  10
  11 void sincos(double x, double *sin, double *cos)
  12 {
  13         double y[2],z=0.0;
  14         int32_t n, ix;
  15
  16     /* High word of x. */
  17         GET_HIGH_WORD(ix,x);
  18
  19     /* |x| ~< pi/4 */
  20         ix &= 0x7fffffff;
  21         if(ix <= 0x3fe921fb) {
  22             if(ix<0x3e400000)                   /* |x| < 2**-27 */
  23                {if((int)x==0) { *sin=x; *cos=1.0; return; }}    /* generate inexact */
  24             *sin = __kernel_sin(x,z,0);
  25             *cos = __kernel_cos(x,z);
  26             return;
  27         }
  28
  29         /* cos(Inf or NaN) is NaN */
  30         else if (ix>=0x7ff00000) {*sin = *cos = x-x; return; }
  31
  32         /* argument reduction needed */
  33         else {
  34                 n = __ieee754_rem_pio2(x,y);
  35                 switch(n&3) {
  36                 case 0: *sin =  __kernel_sin(y[0],y[1],1); *cos =  __kernel_cos(y[0],y[1]);   break;
  37                 case 1: *sin =  __kernel_cos(y[0],y[1]);   *cos = -__kernel_sin(y[0],y[1],1); break;
  38                 case 2: *sin = -__kernel_sin(y[0],y[1],1); *cos = -__kernel_cos(y[0],y[1]);   break;
  39                 default:
  40                         *sin = -__kernel_cos(y[0],y[1]); *cos = __kernel_sin(y[0],y[1],1);
  41                 }
  42         }
  43 }