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 var S1 = "string1"; 31 var S2 = "@@string2"; 32 33 function dead1(a, b) { 34 var x = %_StringCharCodeAt(a, 4); 35 return a; // x is dead code 36 } 37 38 function dead2(a, b) { 39 var x = %_StringCharCodeAt(a, 3); 40 var y = %_StringCharCodeAt(b, 1); 41 return a; // x and y are both dead 42 } 43 44 function dead3(a, b) { 45 a = a ? "11" : "12"; 46 b = b ? "13" : "14"; 47 var x = %_StringCharCodeAt(a, 2); 48 var y = %_StringCharCodeAt(b, 0); 49 return a; // x and y are both dead 50 } 51 52 function test() { 53 var S3 = S1 + S2; 54 55 assertEquals(S1, dead1(S1, S2)); 56 assertEquals(S1, dead2(S1, S2)); 57 assertEquals("11", dead3(S1, S2)); 58 59 assertEquals(S2, dead1(S2, 677)); 60 assertEquals(S2, dead2(S2, S3)); 61 assertEquals("11", dead3(S2, S3)); 62 63 assertEquals(S3, dead1(S3, 399)); 64 assertEquals(S3, dead2(S3, "false")); 65 assertEquals("12", dead3(0, 32)); 66 67 assertEquals(S3, dead1(S3, 0)); 68 assertEquals(S3, dead2(S3, S1)); 69 assertEquals("11", dead3(S3, 0)); 70 71 assertEquals("true", dead1("true", 0)); 72 assertEquals("true", dead2("true", S3)); 73 assertEquals("11", dead3("true", 0)); 74 } 75 76 test(); 77 test(); 78 %OptimizeFunctionOnNextCall(dead1); 79 %OptimizeFunctionOnNextCall(dead2); 80 %OptimizeFunctionOnNextCall(dead3); 81 test(); 82