compiler/stdc/math/s_sincosf.c

   1 /* s_sincosf.c -- float version of s_sincos.c
   2  *
   3  * Copyright (C) 2013 Elliot Saba
   4  * Developed at the University of Washington
   5  *
   6  * Permission to use, copy, modify, and distribute this
   7  * software is freely granted, provided that this notice
   8  * is preserved.
   9  * ====================================================
  10 */
  11
  12 #include <aros/debug.h>
  13
  14 #include "math.h"
  15 #define INLINE_REM_PIO2F
  16 #include "math_private.h"
  17 #include "e_rem_pio2f.c"
  18 #include "k_sincosf.h"
  19
  20 /* Small multiples of pi/2 rounded to double precision. */
  21 static const double
  22 p1pio2 = 1*M_PI_2,                      /* 0x3FF921FB, 0x54442D18 */
  23 p2pio2 = 2*M_PI_2,                      /* 0x400921FB, 0x54442D18 */
  24 p3pio2 = 3*M_PI_2,                      /* 0x4012D97C, 0x7F3321D2 */
  25 p4pio2 = 4*M_PI_2;                      /* 0x401921FB, 0x54442D18 */
  26
  27 void
  28 sincosf(float x, float *sn, float *cs)
  29 {
  30         float c, s;
  31         double y;
  32         int32_t n, hx, ix;
  33
  34         GET_FLOAT_WORD(hx,x);
  35         ix = hx & 0x7fffffff;
  36
  37         if(ix <= 0x3f490fda) {          /* |x| ~<= pi/4 */
  38             if(ix<0x39800000) {         /* |x| < 2**-12 */
  39                         if ((int)x == 0) {
  40                                 *sn = x;        /* x with inexact if x != 0 */
  41                                 *cs = 1;
  42                                 return;
  43                         }
  44                 }
  45                 __kernel_sincosdf(x, sn, cs);
  46                 return;
  47         }
  48
  49         if (ix <= 0x407b53d1) {         /* |x| ~<= 5*pi/4 */
  50                 if (ix <= 0x4016cbe3) { /* |x| ~<= 3pi/4 */
  51                         if(hx>0) {
  52                                 __kernel_sincosdf(x - p1pio2, cs, sn);
  53                                 *cs = -*cs;
  54                         } else {
  55                                 __kernel_sincosdf(x + p1pio2, cs, sn);
  56                                 *sn = -*sn;
  57                         }
  58                 } else {
  59                         if (hx > 0)
  60                                 __kernel_sincosdf(x - p2pio2, sn, cs);
  61                         else
  62                                 __kernel_sincosdf(x + p2pio2, sn, cs);
  63                         *sn = -*sn;
  64                         *cs = -*cs;
  65                 }
  66                 return;
  67         }
  68
  69         if (ix <= 0x40e231d5) {         /* |x| ~<= 9*pi/4 */
  70                 if (ix <= 0x40afeddf) { /* |x| ~<= 7*pi/4 */
  71                         if(hx>0) {
  72                                 __kernel_sincosdf(x - p3pio2, cs, sn);
  73                                 *sn = -*sn;
  74                         } else {
  75                                 __kernel_sincosdf(x + p3pio2, cs, sn);
  76                                 *cs = -*cs;
  77                         }
  78                 } else {
  79                         if (hx > 0)
  80                                 __kernel_sincosdf(x - p4pio2, sn, cs);
  81                         else
  82                                 __kernel_sincosdf(x + p4pio2, sn, cs);
  83                 }
  84                 return;
  85         }
  86
  87         /* If x = Inf or NaN, then sin(x) = NaN and cos(x) = NaN. */
  88         if (ix >= 0x7f800000) {
  89                 *sn = x - x;
  90                 *cs = x - x;
  91                 return;
  92         }
  93
  94         /* Argument reduction. */
  95                 n = __ieee754_rem_pio2f(x,&y);
  96         __kernel_sincosdf(y, &s, &c);
  97
  98                 switch(n&3) {
  99                         case 0:
 100                 *sn = s;
 101                 *cs = c;
 102                                 break;
 103                         case 1:
 104                 *sn = c;
 105                 *cs = -s;
 106                                 break;
 107                         case 2:
 108                 *sn = -s;
 109                 *cs = -c;
 110                                 break;
 111                         default:
 112                 *sn = -c;
 113                 *cs = s;
 114         }
 115 }
 116
 117