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 /*
  27  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  28  * Use is subject to license terms.
  29  */
  30 
  31 
  32 /*
  33  * long double __k_sincos( long double x, long double y, long double *c )
  34  * kernel sincosl function on [-pi/4, pi/4], pi/4 ~ 0.785398164
  35  * Input x is assumed to be bounded by ~pi/4 in magnitude.
  36  * Input y is the tail of x.
  37  * return sinl(x) with *c = cosl(x)
  38  *
  39  * Table look up algorithm
  40  *      see __k_sinl() and __k_cosl()
  41  */
  42 
  43 #include "libm.h"
  44 
  45 #include <sys/isa_defs.h>
  46 
  47 extern const long double _TBL_sinl_hi[], _TBL_sinl_lo[], _TBL_cosl_hi[],
  48         _TBL_cosl_lo[];
  49 static const long double one = 1.0;
  50 
  51 /*
  52  * |sin(x) - (x+pp1*x^3+...+pp5*x^11)| <= 2^-122.32 for |x|<1/64
  53  */
  54 static const long double
  55         pp1 = -1.666666666666666666666666666586782940810e-0001L,
  56         pp2 = 8.333333333333333333333003723660929317540e-0003L,
  57         pp3 = -1.984126984126984076045903483778337804470e-0004L,
  58         pp4 = 2.755731922361906641319723106210900949413e-0006L,
  59         pp5 = -2.505198398570947019093998469135012057673e-0008L;
  60 
  61 /*
  62  * |(sin(x) - (x+p1*x^3+...+p8*x^17)|
  63  * |------------------------------- | <= 2^-116.17 for |x|<0.1953125
  64  * |                 x              |
  65  */
  66 static const long double
  67         p1 = -1.666666666666666666666666666666211262297e-0001L,
  68         p2 = 8.333333333333333333333333301497876908541e-0003L,
  69         p3 = -1.984126984126984126984041302881180621922e-0004L,
  70         p4 = 2.755731922398589064100587351307269621093e-0006L,
  71         p5 = -2.505210838544163129378906953765595393873e-0008L,
  72         p6 = 1.605904383643244375050998243778534074273e-0010L,
  73         p7 = -7.647162722800685516901456114270824622699e-0013L,
  74         p8 = 2.810046428661902961725428841068844462603e-0015L;
  75 
  76 /*
  77  *
  78  * |cos(x) - (1+qq1*x^2+...+ qq5*x^10)| <= 2^-123.84 for |x|<=1/128
  79  */
  80 static const long double
  81         qq1 = -4.999999999999999999999999999999378373641e-0001L,
  82         qq2 = 4.166666666666666666666665478399327703130e-0002L,
  83         qq3 = -1.388888888888888888058211230618051613494e-0003L,
  84         qq4 = 2.480158730156105377771585658905303111866e-0005L,
  85         qq5 = -2.755728099762526325736488376695157008736e-0007L;
  86 
  87 /*
  88  *
  89  * |cos(x) - (1+q1*x^2+...+ q8*x^16)| <= 2^-117.11 for |x|<= 0.15625
  90  */
  91 static const long double
  92         q1 = -4.999999999999999999999999999999756416975e-0001L,
  93         q2 = 4.166666666666666666666666664006066577258e-0002L,
  94         q3 = -1.388888888888888888888877700363937169637e-0003L,
  95         q4 = 2.480158730158730158494468463031814083559e-0005L,
  96         q5 = -2.755731922398586276322819250356005542871e-0007L,
  97         q6 = 2.087675698767424261441959760729854017855e-0009L,
  98         q7 = -1.147074481239662089072452129010790774761e-0011L,
  99         q8 = 4.777761647399651599730663422263531034782e-0014L;
 100 
 101 
 102 long double
 103 __k_sincosl(long double x, long double y, long double *c)
 104 {
 105         long double a1, a2, t, t1, t2, z, w;
 106         int *pt = (int *)&t, *px = (int *)&x;
 107         int i, j, hx, ix;
 108 
 109         t = 1.0;
 110 #if defined(__i386) || defined(__amd64)
 111         XTOI(px, hx);
 112 #else
 113         hx = px[0];
 114 #endif
 115         ix = hx & 0x7fffffff;
 116 
 117         if (ix < 0x3ffc4000) {
 118                 if (ix < 0x3fc60000) {
 119                         if (((int)x) == 0) {
 120                                 *c = one;
 121                                 return (x);
 122                         }               /* generate inexact */
 123                 }
 124 
 125                 z = x * x;
 126 
 127                 if (ix < 0x3ff80000) {
 128                         *c = one + z * (qq1 + z * (qq2 + z * (qq3 + z * (qq4 +
 129                             z * qq5))));
 130                         t = z * (p1 + z * (p2 + z * (p3 + z * (p4 + z * (p5 +
 131                             z * p6)))));
 132                 } else {
 133                         *c = one + z * (q1 + z * (q2 + z * (q3 + z * (q4 + z *
 134                             (q5 + z * (q6 + z * (q7 + z * q8)))))));
 135                         t = z * (p1 + z * (p2 + z * (p3 + z * (p4 + z * (p5 +
 136                             z * (p6 + z * (p7 + z * p8)))))));
 137                 }
 138 
 139                 t = y + x * t;
 140                 return (x + t);
 141         }
 142 
 143         j = (ix + 0x400) & 0x7ffff800;
 144         i = (j - 0x3ffc4000) >> 11;
 145 #if defined(__i386) || defined(__amd64)
 146         ITOX(j, pt);
 147 #else
 148         pt[0] = j;
 149 #endif
 150 
 151         if (hx > 0)
 152                 x = y - (t - x);
 153         else
 154                 x = (-y) - (t + x);
 155 
 156         a1 = _TBL_sinl_hi[i];
 157         z = x * x;
 158         t = z * (qq1 + z * (qq2 + z * (qq3 + z * (qq4 + z * qq5))));
 159         w = x * (one + z * (pp1 + z * (pp2 + z * (pp3 + z * (pp4 + z * pp5)))));
 160         a2 = _TBL_cosl_hi[i];
 161         t2 = _TBL_cosl_lo[i] - (a1 * w - a2 * t);
 162         *c = a2 + t2;
 163         t1 = a2 * w + a1 * t;
 164         t1 += _TBL_sinl_lo[i];
 165 
 166         if (hx < 0)
 167                 return (-a1 - t1);
 168         else
 169                 return (a1 + t1);
 170 }