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 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 23 */ 24 /* 25 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 26 * Use is subject to license terms. 27 */ 28 29 #pragma weak __rint = rint 30 31 /* 32 * rint(x) return x rounded to integral according to the rounding direction 33 * rint(x) returns result with the same sign as x's, including 0.0. 34 */ 35 36 #include "libm.h" 37 38 #if defined(__i386) && !defined(__amd64) && (!defined(__FLT_EVAL_METHOD__) || \ 39 __FLT_EVAL_METHOD__ != 0) 40 extern enum fp_precision_type __swapRP(enum fp_precision_type); 41 #define DECLRP(x) enum fp_precision_type x; 42 #define SWAPRP(new, x) x = __swapRP(new); 43 #define RESTRP(x) (void) __swapRP(x); 44 #else 45 #define DECLRP(x) 46 #define SWAPRP(new, x) 47 #define RESTRP(x) 48 #endif 49 50 static const double 51 two52 = 4503599627370496.0, 52 zero = 0.0, 53 one = 1.0; 54 55 double 56 rint(double x) { 57 DECLRP(rp) 58 double t, w; 59 int ix, hx; 60 61 ix = ((int *)&x)[HIWORD]; 62 hx = ix & ~0x80000000; 63 64 if (hx >= 0x43300000) 65 return (x * one); 66 t = (ix < 0)? -two52 : two52; 67 SWAPRP(fp_double, rp) /* set precision mode to double */ 68 w = x + t; /* x+sign(x)*2**52 rounded */ 69 RESTRP(rp) /* restore precision mode */ 70 if (w == t) 71 return ((ix < 0)? -zero : zero); 72 return (w - t); 73 } 74