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