1 // Copyright 2008 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 // Test some dead code elimination scenarios 30 31 function dead1(x, y) { 32 var a = x | 0, b = y | 0; 33 a * b; 34 a << b; 35 a >> b; 36 a >>> b; 37 a | b; 38 a & b; 39 a ^ b; 40 return x; 41 } 42 43 function dead2(x, y) { 44 var a = x | 0, b = y | 0; 45 (a | 0) * b; 46 (a | 0) << b; 47 (a | 0) >> b; 48 (a | 0) >>> b; 49 (a | 0) | b; 50 (a | 0) & b; 51 (a | 0) ^ b; 52 return x; 53 } 54 55 function dead3(a, b) { 56 a == 2 ? (a * b) : (b * a); // dead 57 return a; 58 } 59 60 assertTrue(dead1(33, 32) == 33); 61 assertTrue(dead1(33, 32) == 33); 62 %OptimizeFunctionOnNextCall(dead1); 63 assertTrue(dead1(33, 32) == 33); 64 65 assertTrue(dead2(34, 11) == 34); 66 assertTrue(dead2(34, 11) == 34); 67 %OptimizeFunctionOnNextCall(dead2); 68 assertTrue(dead2(34, 11) == 34); 69 70 assertTrue(dead3(35, 12) == 35); 71 assertTrue(dead3(35, 12) == 35); 72 %OptimizeFunctionOnNextCall(dead3); 73 assertTrue(dead3(35, 12) == 35); 74