/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* ***** BEGIN LICENSE BLOCK ***** * Version: MPL 1.1/GPL 2.0/LGPL 2.1 * * The contents of this file are subject to the Mozilla Public License Version * 1.1 (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the * License. * * The Original Code is Mozilla Communicator client code, released * March 31, 1998. * * The Initial Developer of the Original Code is * Netscape Communications Corporation. * Portions created by the Initial Developer are Copyright (C) 1998 * the Initial Developer. All Rights Reserved. * * Contributor(s): * * Alternatively, the contents of this file may be used under the terms of * either the GNU General Public License Version 2 or later (the "GPL"), or * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), * in which case the provisions of the GPL or the LGPL are applicable instead * of those above. If you wish to allow use of your version of this file only * under the terms of either the GPL or the LGPL, and not to allow others to * use your version of this file under the terms of the MPL, indicate your * decision by deleting the provisions above and replace them with the notice * and other provisions required by the GPL or the LGPL. If you do not delete * the provisions above, a recipient may use your version of this file under * the terms of any one of the MPL, the GPL or the LGPL. * * ***** END LICENSE BLOCK ***** */ /** File Name: 11.7.3.js ECMA Section: 11.7.3 The unsigned right shift operator ( >>> ) Description: 11.7.3 The unsigned right shift operator ( >>> ) Performs a zero-filling bitwise right shift operation on the left argument by the amount specified by the right argument. The production ShiftExpression : ShiftExpression >>> AdditiveExpression is evaluated as follows: 1. Evaluate ShiftExpression. 2. Call GetValue(Result(1)). 3. Evaluate AdditiveExpression. 4. Call GetValue(Result(3)). 5. Call ToUint32(Result(2)). 6. Call ToUint32(Result(4)). 7. Mask out all but the least significant 5 bits of Result(6), that is, compute Result(6) & 0x1F. 8. Perform zero-filling right shift of Result(5) by Result(7) bits. Vacated bits are filled with zero. The result is an unsigned 32 bit integer. 9. Return Result(8). Author: christine@netscape.com Date: 12 november 1997 */ var SECTION = "11.7.3"; var VERSION = "ECMA_1"; startTest(); writeHeaderToLog( SECTION + " The unsigned right shift operator ( >>> )"); var addexp = 0; var power = 0; for ( power = 0; power <= 32; power++ ) { shiftexp = Math.pow( 2, power ); for ( addexp = 0; addexp <= 32; addexp++ ) { new TestCase( SECTION, shiftexp + " >>> " + addexp, UnsignedRightShift( shiftexp, addexp ), shiftexp >>> addexp ); } } test(); function ToInteger( n ) { n = Number( n ); var sign = ( n < 0 ) ? -1 : 1; if ( n != n ) { return 0; } if ( Math.abs( n ) == 0 || Math.abs( n ) == Number.POSITIVE_INFINITY ) { return n; } return ( sign * Math.floor(Math.abs(n)) ); } function ToInt32( n ) { n = Number( n ); var sign = ( n < 0 ) ? -1 : 1; if ( Math.abs( n ) == 0 || Math.abs( n ) == Number.POSITIVE_INFINITY) { return 0; } n = (sign * Math.floor( Math.abs(n) )) % Math.pow(2,32); n = ( n >= Math.pow(2,31) ) ? n - Math.pow(2,32) : n; return ( n ); } function ToUint32( n ) { n = Number( n ); var sign = ( n < 0 ) ? -1 : 1; if ( Math.abs( n ) == 0 || Math.abs( n ) == Number.POSITIVE_INFINITY) { return 0; } n = sign * Math.floor( Math.abs(n) ) n = n % Math.pow(2,32); if ( n < 0 ){ n += Math.pow(2,32); } return ( n ); } function ToUint16( n ) { var sign = ( n < 0 ) ? -1 : 1; if ( Math.abs( n ) == 0 || Math.abs( n ) == Number.POSITIVE_INFINITY) { return 0; } n = ( sign * Math.floor( Math.abs(n) ) ) % Math.pow(2,16); if (n <0) { n += Math.pow(2,16); } return ( n ); } function Mask( b, n ) { b = ToUint32BitString( b ); b = b.substring( b.length - n ); b = ToUint32Decimal( b ); return ( b ); } function ToUint32BitString( n ) { var b = ""; for ( p = 31; p >=0; p-- ) { if ( n >= Math.pow(2,p) ) { b += "1"; n -= Math.pow(2,p); } else { b += "0"; } } return b; } function ToInt32BitString( n ) { var b = ""; var sign = ( n < 0 ) ? -1 : 1; b += ( sign == 1 ) ? "0" : "1"; for ( p = 30; p >=0; p-- ) { if ( (sign == 1 ) ? sign * n >= Math.pow(2,p) : sign * n > Math.pow(2,p) ) { b += ( sign == 1 ) ? "1" : "0"; n -= sign * Math.pow( 2, p ); } else { b += ( sign == 1 ) ? "0" : "1"; } } return b; } function ToInt32Decimal( bin ) { var r = 0; var sign; if ( Number(bin.charAt(0)) == 0 ) { sign = 1; r = 0; } else { sign = -1; r = -(Math.pow(2,31)); } for ( var j = 0; j < 31; j++ ) { r += Math.pow( 2, j ) * Number(bin.charAt(31-j)); } return r; } function ToUint32Decimal( bin ) { var r = 0; for ( l = bin.length; l < 32; l++ ) { bin = "0" + bin; } for ( j = 0; j < 32; j++ ) { r += Math.pow( 2, j ) * Number(bin.charAt(31-j)); } return r; } function RShift( s, a ) { s = ToUint32BitString( s ); for ( z = 0; z < a; z++ ) { s = "0" + s; } s = s.substring( 0, s.length - a ); return ToUint32Decimal(s); } function UnsignedRightShift( s, a ) { s = ToUint32( s ); a = ToUint32( a ); a = Mask( a, 5 ); return ( RShift( s, a ) ); }