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