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 /* 31 * __rem_pio2l(x,y) 32 * 33 * return the remainder of x rem pi/2 in y[0]+y[1] by calling __rem_pio2m 34 */ 35 36 #ifndef FDLIBM_BASED 37 #include "libm.h" 38 extern int __rem_pio2m(double *, double *, int, int, int, const int *); 39 #else /* FDLIBM_BASED */ 40 #include "fdlibm.h" 41 #define __rem_pio2m __kernel_rem_pio2 42 #endif /* FDLIBM_BASED */ 43 44 #include "longdouble.h" 45 46 extern const int _TBL_ipio2l_inf[]; 47 48 static const long double 49 two24l = 16777216.0L, 50 pio4 = 0.7853981633974483096156608458198757210495L; 51 52 int 53 __rem_pio2l(long double x, long double *y) 54 { 55 long double z, w; 56 double t[5], v[5]; 57 int e0, i, nx, n, sign; 58 const int *ipio2; 59 60 sign = signbitl(x); 61 z = fabsl(x); 62 if (z <= pio4) { 63 y[0] = x; 64 y[1] = 0; 65 return (0); 66 } 67 e0 = ilogbl(z) - 23; 68 z = scalbnl(z, -e0); 69 for (i = 0; i < 5; i++) { 70 t[i] = (double)((int)(z)); 71 z = (z - (long double)t[i]) * two24l; 72 } 73 nx = 5; 74 while (t[nx - 1] == 0.0) 75 nx--; /* skip zero term */ 76 ipio2 = _TBL_ipio2l_inf; 77 n = __rem_pio2m(t, v, e0, nx, 3, (const int *)ipio2); 78 z = (long double)v[2] + (long double)v[1]; 79 w = (long double)v[0]; 80 y[0] = z + w; 81 y[1] = z - (y[0] - w); 82 if (sign != 0) { 83 y[0] = -y[0]; 84 y[1] = -y[1]; 85 return (-n); 86 } 87 return (n); 88 } 89