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      1 // Copyright 2013 the V8 project authors. All rights reserved.
      2 // Redistribution and use in source and binary forms, with or without
      3 // modification, are permitted provided that the following conditions are
      4 // met:
      5 //
      6 //     * Redistributions of source code must retain the above copyright
      7 //       notice, this list of conditions and the following disclaimer.
      8 //     * Redistributions in binary form must reproduce the above
      9 //       copyright notice, this list of conditions and the following
     10 //       disclaimer in the documentation and/or other materials provided
     11 //       with the distribution.
     12 //     * Neither the name of Google Inc. nor the names of its
     13 //       contributors may be used to endorse or promote products derived
     14 //       from this software without specific prior written permission.
     15 //
     16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27 
     28 // Flags: --allow-natives-syntax
     29 
     30 function dead1(a, b) {
     31     var x = %_StringCharFromCode(a);
     32     return a; // x is dead code
     33 }
     34 
     35 function dead2(a, b) {
     36     var x = %_StringCharFromCode(a);
     37     var y = %_StringCharFromCode(b);
     38     return a; // x and y are both dead
     39 }
     40 
     41 function dead3(a, b) {
     42     a = a ? 11 : 12;
     43     b = b ? 13 : 14;
     44     var x = %_StringCharFromCode(a);
     45     var y = %_StringCharFromCode(b);
     46     return a; // x and y are both dead
     47 }
     48 
     49 function test() {
     50     assertEquals(33, dead1(33, 32));
     51     assertEquals(33, dead2(33, 32));
     52     assertEquals(11, dead3(33, 32));
     53 
     54     assertEquals(31, dead1(31, 30));
     55     assertEquals(31, dead2(31, 30));
     56     assertEquals(11, dead3(31, 32));
     57 
     58     assertEquals(0, dead1(0, 30));
     59     assertEquals(0, dead2(0, 30));
     60     assertEquals(12, dead3(0, 32));
     61 
     62     assertEquals(true, dead1(true, 0));
     63     assertEquals(true, dead2(true, 0));
     64     assertEquals(11, dead3(true, 0));
     65 
     66     assertEquals("true", dead1("true", 0));
     67     assertEquals("true", dead2("true", 0));
     68     assertEquals(11, dead3("true", 0));
     69 }
     70 
     71 test();
     72 test();
     73 %OptimizeFunctionOnNextCall(dead1);
     74 %OptimizeFunctionOnNextCall(dead2);
     75 %OptimizeFunctionOnNextCall(dead3);
     76 test();
     77