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 #pragma weak __lround = lround 31 32 /* 33 * lround(x) rounds its argument to the nearest integer, rounding ties 34 * away from zero, and converts the result to a 32 bit signed integer. 35 * 36 * If x is NaN, infinite, or so large that the nearest integer 37 * would exceed 32 bits, the invalid operation exception is raised. 38 */ 39 40 #include <sys/isa_defs.h> /* _ILP32 */ 41 #include "libm.h" 42 43 #if defined(_ILP32) 44 long 45 lround(double x) { 46 union { 47 unsigned i[2]; 48 double d; 49 } xx; 50 unsigned hx, sx, i; 51 52 xx.d = x; 53 hx = xx.i[HIWORD] & ~0x80000000; 54 sx = xx.i[HIWORD] & 0x80000000; 55 if (hx < 0x43300000) { /* |x| < 2^52 */ 56 if (hx < 0x3ff00000) { /* |x| < 1 */ 57 if (hx >= 0x3fe00000) 58 return (sx ? -1L : 1L); 59 return (0L); 60 } 61 62 /* round x at the integer bit */ 63 if (hx < 0x41300000) { 64 i = 1 << (0x412 - (hx >> 20)); 65 xx.i[HIWORD] = (xx.i[HIWORD] + i) & ~(i | (i - 1)); 66 xx.i[LOWORD] = 0; 67 } else { 68 i = 1 << (0x432 - (hx >> 20)); 69 xx.i[LOWORD] += i; 70 if (xx.i[LOWORD] < i) 71 xx.i[HIWORD]++; 72 xx.i[LOWORD] &= ~(i | (i - 1)); 73 } 74 } 75 76 /* now x is nan, inf, or integral */ 77 return ((long) xx.d); 78 } 79 #else 80 #error Unsupported architecture 81 #endif /* defined(_ILP32) */