tests/mozilla/ecma/Expressions/11.7.3.js

   1 /* The contents of this file are subject to the Netscape Public
   2  * License Version 1.1 (the "License"); you may not use this file
   3  * except in compliance with the License. You may obtain a copy of
   4  * the License at http://www.mozilla.org/NPL/
   5  *
   6  * Software distributed under the License is distributed on an "AS
   7  * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
   8  * implied. See the License for the specific language governing
   9  * rights and limitations under the License.
  10  *
  11  * The Original Code is Mozilla Communicator client code, released March
  12  * 31, 1998.
  13  *
  14  * The Initial Developer of the Original Code is Netscape Communications
  15  * Corporation. Portions created by Netscape are
  16  * Copyright (C) 1998 Netscape Communications Corporation. All
  17  * Rights Reserved.
  18  *
  19  * Contributor(s):
  20  *
  21  */
  22 /**
  23     File Name:          11.7.3.js
  24     ECMA Section:       11.7.3  The unsigned right shift operator ( >>> )
  25     Description:
  26     11.7.3 The unsigned right shift operator ( >>> )
  27     Performs a zero-filling bitwise right shift operation on the left argument
  28     by the amount specified by the right argument.
  29
  30     The production ShiftExpression : ShiftExpression >>> AdditiveExpression is
  31     evaluated as follows:
  32
  33     1.  Evaluate ShiftExpression.
  34     2.  Call GetValue(Result(1)).
  35     3.  Evaluate AdditiveExpression.
  36     4.  Call GetValue(Result(3)).
  37     5.  Call ToUint32(Result(2)).
  38     6.  Call ToUint32(Result(4)).
  39     7.  Mask out all but the least significant 5 bits of Result(6), that is,
  40         compute Result(6) & 0x1F.
  41     8.  Perform zero-filling right shift of Result(5) by Result(7) bits.
  42         Vacated bits are filled with zero. The result is an unsigned 32 bit
  43         integer.
  44     9.  Return Result(8).
  45
  46     Author:             christine@netscape.com
  47     Date:               12 november 1997
  48 */
  49     var SECTION = "11.7.3";
  50     var VERSION = "ECMA_1";
  51     startTest();
  52     var testcases = getTestCases();
  53
  54     writeHeaderToLog( SECTION + "  The unsigned right shift operator ( >>> )");
  55     test();
  56
  57 function test() {
  58     for ( tc=0; tc < testcases.length; tc++ ) {
  59         testcases[tc].passed = writeTestCaseResult(
  60                             testcases[tc].expect,
  61                             testcases[tc].actual,
  62                             testcases[tc].description +" = "+
  63                             testcases[tc].actual );
  64
  65         testcases[tc].reason += ( testcases[tc].passed ) ? "" : "wrong value ";
  66     }
  67     stopTest();
  68     return ( testcases );
  69 }
  70 function getTestCases() {
  71     var array = new Array();
  72     var item = 0;
  73
  74     var addexp = 0;
  75     var power = 0;
  76
  77     for ( power = 0; power <= 32; power++ ) {
  78         shiftexp = Math.pow( 2, power );
  79
  80         for ( addexp = 0; addexp <= 32; addexp++ ) {
  81             array[item++] = new TestCase( SECTION,
  82                                     shiftexp + " >>> " + addexp,
  83                                     UnsignedRightShift( shiftexp, addexp ),
  84                                     shiftexp >>> addexp );
  85          }
  86     }
  87
  88     return ( array );
  89 }
  90
  91 function ToInteger( n ) {
  92     n = Number( n );
  93     var sign = ( n < 0 ) ? -1 : 1;
  94
  95     if ( n != n ) {
  96         return 0;
  97     }
  98     if ( Math.abs( n ) == 0 || Math.abs( n ) == Number.POSITIVE_INFINITY ) {
  99         return n;
 100     }
 101     return ( sign * Math.floor(Math.abs(n)) );
 102 }
 103 function ToInt32( n ) {
 104     n = Number( n );
 105     var sign = ( n < 0 ) ? -1 : 1;
 106
 107     if ( Math.abs( n ) == 0 || Math.abs( n ) == Number.POSITIVE_INFINITY) {
 108         return 0;
 109     }
 110
 111     n = (sign * Math.floor( Math.abs(n) )) % Math.pow(2,32);
 112     n = ( n >= Math.pow(2,31) ) ? n - Math.pow(2,32) : n;
 113
 114     return ( n );
 115 }
 116 function ToUint32( n ) {
 117     n = Number( n );
 118     var sign = ( n < 0 ) ? -1 : 1;
 119
 120     if ( Math.abs( n ) == 0 || Math.abs( n ) == Number.POSITIVE_INFINITY) {
 121         return 0;
 122     }
 123     n = sign * Math.floor( Math.abs(n) )
 124
 125     n = n % Math.pow(2,32);
 126
 127     if ( n < 0 ){
 128         n += Math.pow(2,32);
 129     }
 130
 131     return ( n );
 132 }
 133 function ToUint16( n ) {
 134     var sign = ( n < 0 ) ? -1 : 1;
 135
 136     if ( Math.abs( n ) == 0 || Math.abs( n ) == Number.POSITIVE_INFINITY) {
 137         return 0;
 138     }
 139
 140     n = ( sign * Math.floor( Math.abs(n) ) ) % Math.pow(2,16);
 141
 142     if (n <0) {
 143         n += Math.pow(2,16);
 144     }
 145
 146     return ( n );
 147 }
 148 function Mask( b, n ) {
 149     b = ToUint32BitString( b );
 150     b = b.substring( b.length - n );
 151     b = ToUint32Decimal( b );
 152     return ( b );
 153 }
 154 function ToUint32BitString( n ) {
 155     var b = "";
 156     for ( p = 31; p >=0; p-- ) {
 157         if ( n >= Math.pow(2,p) ) {
 158             b += "1";
 159             n -= Math.pow(2,p);
 160         } else {
 161             b += "0";
 162         }
 163     }
 164     return b;
 165 }
 166 function ToInt32BitString( n ) {
 167     var b = "";
 168     var sign = ( n < 0 ) ? -1 : 1;
 169
 170     b += ( sign == 1 ) ? "0" : "1";
 171
 172     for ( p = 30; p >=0; p-- ) {
 173         if ( (sign == 1 ) ? sign * n >= Math.pow(2,p) : sign * n > Math.pow(2,p) ) {
 174             b += ( sign == 1 ) ? "1" : "0";
 175             n -= sign * Math.pow( 2, p );
 176         } else {
 177             b += ( sign == 1 ) ? "0" : "1";
 178         }
 179     }
 180
 181     return b;
 182 }
 183 function ToInt32Decimal( bin ) {
 184     var r = 0;
 185     var sign;
 186
 187     if ( Number(bin.charAt(0)) == 0 ) {
 188         sign = 1;
 189         r = 0;
 190     } else {
 191         sign = -1;
 192         r = -(Math.pow(2,31));
 193     }
 194
 195     for ( var j = 0; j < 31; j++ ) {
 196         r += Math.pow( 2, j ) * Number(bin.charAt(31-j));
 197     }
 198
 199     return r;
 200 }
 201 function ToUint32Decimal( bin ) {
 202     var r = 0;
 203
 204
 205     for ( l = bin.length; l < 32; l++ ) {
 206         bin = "0" + bin;
 207     }
 208
 209     for ( j = 0; j < 32; j++ ) {
 210         r += Math.pow( 2, j ) * Number(bin.charAt(31-j));
 211
 212     }
 213
 214     return r;
 215 }
 216 function RShift( s, a ) {
 217     s = ToUint32BitString( s );
 218     for ( z = 0; z < a; z++ ) {
 219         s = "0" + s;
 220     }
 221     s = s.substring( 0, s.length - a );
 222
 223     return ToUint32Decimal(s);
 224 }
 225 function UnsignedRightShift( s, a ) {
 226     s = ToUint32( s );
 227     a = ToUint32( a );
 228     a = Mask( a, 5 );
 229     return ( RShift( s, a ) );
 230 }