newlib/libm/ld/s_sinl.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2007 Steven G. Kargl
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice unmodified, this list of conditions, and the following
  12  *    disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD$");
  31
  32 #include <float.h>
  33 #ifdef __i386__
  34 #include <ieeefp.h>
  35 #endif
  36
  37 #include "math.h"
  38 #include "math_private.h"
  39 #if LDBL_MANT_DIG == 64
  40 #include "../ld80/e_rem_pio2l.h"
  41 #elif LDBL_MANT_DIG == 113
  42 #include "../ld128/e_rem_pio2l.h"
  43 #else
  44 #error "Unsupported long double format"
  45 #endif
  46
  47 long double
  48 sinl(long double x)
  49 {
  50         union IEEEl2bits z;
  51         int e0, s;
  52         long double y[2];
  53         long double hi, lo;
  54
  55         z.e = x;
  56         s = z.bits.sign;
  57         z.bits.sign = 0;
  58
  59         /* If x = +-0 or x is a subnormal number, then sin(x) = x */
  60         if (z.bits.exp == 0)
  61                 return (x);
  62
  63         /* If x = NaN or Inf, then sin(x) = NaN. */
  64         if (z.bits.exp == 32767)
  65                 return ((x - x) / (x - x));
  66
  67         ENTERI();
  68
  69         /* Optimize the case where x is already within range. */
  70         if (z.e < M_PI_4) {
  71                 hi = __kernel_sinl(z.e, 0, 0);
  72                 RETURNI(s ? -hi : hi);
  73         }
  74
  75         e0 = __ieee754_rem_pio2l(x, y);
  76         hi = y[0];
  77         lo = y[1];
  78
  79         switch (e0 & 3) {
  80         case 0:
  81             hi = __kernel_sinl(hi, lo, 1);
  82             break;
  83         case 1:
  84             hi = __kernel_cosl(hi, lo);
  85             break;
  86         case 2:
  87             hi = - __kernel_sinl(hi, lo, 1);
  88             break;
  89         case 3:
  90             hi = - __kernel_cosl(hi, lo);
  91             break;
  92         }
  93
  94         RETURNI(hi);
  95 }