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 long double z, w; 55 double t[5], v[5]; 56 int e0, i, nx, n, sign; 57 const int *ipio2; 58 59 sign = signbitl(x); 60 z = fabsl(x); 61 if (z <= pio4) { 62 y[0] = x; 63 y[1] = 0; 64 return (0); 65 } 66 e0 = ilogbl(z) - 23; 67 z = scalbnl(z, -e0); 68 for (i = 0; i < 5; i++) { 69 t[i] = (double) ((int) (z)); 70 z = (z - (long double) t[i]) * two24l; 71 } 72 nx = 5; 73 while (t[nx - 1] == 0.0) 74 nx--; /* skip zero term */ 75 ipio2 = _TBL_ipio2l_inf; 76 n = __rem_pio2m(t, v, e0, nx, 3, (const int *) ipio2); 77 z = (long double) v[2] + (long double) v[1]; 78 w = (long double) v[0]; 79 y[0] = z + w; 80 y[1] = z - (y[0] - w); 81 if (sign == 1) { 82 y[0] = -y[0]; 83 y[1] = -y[1]; 84 return (-n); 85 } 86 return (n); 87 } 88