lib/msun/src/s_sincosf.c

   1 /*-
   2  * ====================================================
   3  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   4  *
   5  * Developed at SunPro, 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
  12 /* s_sincosf.c -- float version of s_sincos.c.
  13  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
  14  * Optimized by Bruce D. Evans.
  15  * Merged s_sinf.c and s_cosf.c by Steven G. Kargl.
  16  */
  17
  18 #include <sys/cdefs.h>
  19 __FBSDID("$FreeBSD$");
  20
  21 #include <float.h>
  22
  23 #include "math.h"
  24 #define INLINE_REM_PIO2F
  25 #include "math_private.h"
  26 #include "e_rem_pio2f.c"
  27 #include "k_sincosf.h"
  28
  29 /* Small multiples of pi/2 rounded to double precision. */
  30 static const double
  31 p1pio2 = 1*M_PI_2,                      /* 0x3FF921FB, 0x54442D18 */
  32 p2pio2 = 2*M_PI_2,                      /* 0x400921FB, 0x54442D18 */
  33 p3pio2 = 3*M_PI_2,                      /* 0x4012D97C, 0x7F3321D2 */
  34 p4pio2 = 4*M_PI_2;                      /* 0x401921FB, 0x54442D18 */
  35
  36 void
  37 sincosf(float x, float *sn, float *cs)
  38 {
  39         float c, s;
  40         double y;
  41         int32_t n, hx, ix;
  42
  43         GET_FLOAT_WORD(hx, x);
  44         ix = hx & 0x7fffffff;
  45
  46         if (ix <= 0x3f490fda) {         /* |x| ~<= pi/4 */
  47                 if (ix < 0x39800000) {  /* |x| < 2**-12 */
  48                         if ((int)x == 0) {
  49                                 *sn = x;        /* x with inexact if x != 0 */
  50                                 *cs = 1;
  51                                 return;
  52                         }
  53                 }
  54                 __kernel_sincosdf(x, sn, cs);
  55                 return;
  56         }
  57
  58         if (ix <= 0x407b53d1) {         /* |x| ~<= 5*pi/4 */
  59                 if (ix <= 0x4016cbe3) { /* |x| ~<= 3pi/4 */
  60                         if (hx > 0) {
  61                                 __kernel_sincosdf(x - p1pio2, cs, sn);
  62                                 *cs = -*cs;
  63                         } else {
  64                                 __kernel_sincosdf(x + p1pio2, cs, sn);
  65                                 *sn = -*sn;
  66                         }
  67                 } else {
  68                         if (hx > 0)
  69                                 __kernel_sincosdf(x - p2pio2, sn, cs);
  70                         else
  71                                 __kernel_sincosdf(x + p2pio2, sn, cs);
  72                         *sn = -*sn;
  73                         *cs = -*cs;
  74                 }
  75                 return;
  76         }
  77
  78         if (ix <= 0x40e231d5) {         /* |x| ~<= 9*pi/4 */
  79                 if (ix <= 0x40afeddf) { /* |x| ~<= 7*pi/4 */
  80                         if (hx > 0) {
  81                                 __kernel_sincosdf(x - p3pio2, cs, sn);
  82                                 *sn = -*sn;
  83                         } else {
  84                                 __kernel_sincosdf(x + p3pio2, cs, sn);
  85                                 *cs = -*cs;
  86                         }
  87                 } else {
  88                         if (hx > 0)
  89                                 __kernel_sincosdf(x - p4pio2, sn, cs);
  90                         else
  91                                 __kernel_sincosdf(x + p4pio2, sn, cs);
  92                 }
  93                 return;
  94         }
  95
  96         /* If x = Inf or NaN, then sin(x) = NaN and cos(x) = NaN. */
  97         if (ix >= 0x7f800000) {
  98                 *sn = x - x;
  99                 *cs = x - x;
 100                 return;
 101         }
 102
 103         /* Argument reduction. */
 104         n = __ieee754_rem_pio2f(x, &y);
 105         __kernel_sincosdf(y, &s, &c);
 106
 107         switch(n & 3) {
 108         case 0:
 109                 *sn = s;
 110                 *cs = c;
 111                 break;
 112         case 1:
 113                 *sn = c;
 114                 *cs = -s;
 115                 break;
 116         case 2:
 117                 *sn = -s;
 118                 *cs = -c;
 119                 break;
 120         default:
 121                 *sn = -c;
 122                 *cs = s;
 123         }
 124 }
 125
 126