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] 34 * by calling __rem_pio2m 35 */ 36 37 #include "libm.h" 38 #include "longdouble.h" 39 40 extern const int _TBL_ipio2l_inf[]; 41 42 static const long double 43 two24l = 16777216.0L, 44 pio4 = 0.7853981633974483096156608458198757210495L; 45 46 int 47 __rem_pio2l(long double x, long double *y) 48 { 49 long double z, w; 50 double t[3], v[5]; 51 int e0, i, nx, n, sign; 52 53 sign = signbitl(x); 54 z = fabsl(x); 55 if (z <= pio4) { 56 y[0] = x; 57 y[1] = 0; 58 return (0); 59 } 60 e0 = ilogbl(z) - 23; 61 z = scalbnl(z, -e0); 62 for (i = 0; i < 3; i++) { 63 t[i] = (double)((int)(z)); 64 z = (z - (long double)t[i]) * two24l; 65 } 66 nx = 3; 67 while (t[nx-1] == 0.0) 68 nx--; /* omit trailing zeros */ 69 n = __rem_pio2m(t, v, e0, nx, 2, _TBL_ipio2l_inf); 70 z = (long double)v[1]; 71 w = (long double)v[0]; 72 y[0] = z + w; 73 y[1] = z - (y[0] - w); 74 if (sign != 0) { 75 y[0] = -y[0]; 76 y[1] = -y[1]; 77 return (-n); 78 } 79 return (n); 80 } 81