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