1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  24  */
  25 /*
  26  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  27  * Use is subject to license terms.
  28  */
  29 
  30 #pragma weak sincosl = __sincosl
  31 
  32 /* INDENT OFF */
  33 /* cosl(x)
  34  * Table look-up algorithm by K.C. Ng, November, 1989.
  35  *
  36  * kernel function:
  37  *      __k_sincosl     ... sin and cos function on [-pi/4,pi/4]
  38  *      __rem_pio2l     ... argument reduction routine
  39  *
  40  * Method.
  41  *      Let S and C denote the sin and cos respectively on [-PI/4, +PI/4].
  42  *      1. Assume the argument x is reduced to y1+y2 = x-k*pi/2 in
  43  *         [-pi/2 , +pi/2], and let n = k mod 4.
  44  *      2. Let S=S(y1+y2), C=C(y1+y2). Depending on n, we have
  45  *
  46  *          n        sin(x)      cos(x)        tan(x)
  47  *     ----------------------------------------------------------
  48  *          0          S           C             S/C
  49  *          1          C          -S            -C/S
  50  *          2         -S          -C             S/C
  51  *          3         -C           S            -C/S
  52  *     ----------------------------------------------------------
  53  *
  54  * Special cases:
  55  *      Let trig be any of sin, cos, or tan.
  56  *      trig(+-INF)  is NaN, with signals;
  57  *      trig(NaN)    is that NaN;
  58  *
  59  * Accuracy:
  60  *      computer TRIG(x) returns trig(x) nearly rounded.
  61  */
  62 /* INDENT ON */
  63 
  64 #include "libm.h"
  65 #include "libm_synonyms.h"
  66 #include "longdouble.h"
  67 
  68 #include <sys/isa_defs.h>
  69 
  70 void
  71 sincosl(long double x, long double *s, long double *c) {
  72         long double y[2], z = 0.0L;
  73         int n, ix;
  74 #if defined(__i386) || defined(__amd64)
  75         int *px = (int *) &x;
  76 #endif
  77 
  78         /* trig(Inf or NaN) is NaN */
  79         if (!finitel(x)) {
  80                 *s = *c = x - x;
  81                 return;
  82         }
  83 
  84         /* High word of x. */
  85 #if defined(__i386) || defined(__amd64)
  86         XTOI(px, ix);
  87 #else
  88         ix = *(int *) &x;
  89 #endif
  90 
  91         /* |x| ~< pi/4 */
  92         ix &= 0x7fffffff;
  93         if (ix <= 0x3ffe9220)
  94                 *s = __k_sincosl(x, z, c);
  95 
  96         /* argument reduction needed */
  97         else {
  98                 n = __rem_pio2l(x, y);
  99                 switch (n & 3) {
 100                 case 0:
 101                         *s = __k_sincosl(y[0], y[1], c);
 102                         break;
 103                 case 1:
 104                         *c = -__k_sincosl(y[0], y[1], s);
 105                         break;
 106                 case 2:
 107                         *s = -__k_sincosl(y[0], y[1], c);
 108                         *c = -*c;
 109                         break;
 110                 case 3:
 111                         *c = __k_sincosl(y[0], y[1], s);
 112                         *s = -*s;
 113                 }
 114         }
 115 }