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 #if defined(ELFOBJ) 31 #pragma weak lround = __lround 32 #endif 33 34 /* 35 * lround(x) rounds its argument to the nearest integer, rounding ties 36 * away from zero, and converts the result to a 32 bit signed integer. 37 * 38 * If x is NaN, infinite, or so large that the nearest integer 39 * would exceed 32 bits, the invalid operation exception is raised. 40 */ 41 42 #include <sys/isa_defs.h> /* _ILP32 */ 43 #include "libm.h" 44 45 #if defined(_ILP32) 46 long 47 lround(double x) { 48 union { 49 unsigned i[2]; 50 double d; 51 } xx; 52 unsigned hx, sx, i; 53 54 xx.d = x; 55 hx = xx.i[HIWORD] & ~0x80000000; 56 sx = xx.i[HIWORD] & 0x80000000; 57 if (hx < 0x43300000) { /* |x| < 2^52 */ 58 if (hx < 0x3ff00000) { /* |x| < 1 */ 59 if (hx >= 0x3fe00000) 60 return (sx ? -1L : 1L); 61 return (0L); 62 } 63 64 /* round x at the integer bit */ 65 if (hx < 0x41300000) { 66 i = 1 << (0x412 - (hx >> 20)); 67 xx.i[HIWORD] = (xx.i[HIWORD] + i) & ~(i | (i - 1)); 68 xx.i[LOWORD] = 0; 69 } else { 70 i = 1 << (0x432 - (hx >> 20)); 71 xx.i[LOWORD] += i; 72 if (xx.i[LOWORD] < i) 73 xx.i[HIWORD]++; 74 xx.i[LOWORD] &= ~(i | (i - 1)); 75 } 76 } 77 78 /* now x is nan, inf, or integral */ 79 return ((long) xx.d); 80 } 81 #else 82 #error Unsupported architecture 83 #endif /* defined(_ILP32) */ 84