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// Presents negative opportunities for dead loop removal. 31 32function loop1() { 33 while (true) return; 34} 35 36function loop2() { 37 var i = 0; 38 while (i++ < 10) ; 39 return i; // value of {i} escapes. 40 // can only remove the loop with induction variable analysis. 41} 42 43function loop3() { 44 var i = 0; 45 for (; i < 10; i++) ; 46 return i; // value of {i} escapes. 47 // can only remove the loop with induction variable analysis. 48} 49 50function loop4() { 51 var a = 0; 52 for (var i = 0; i < 10; i++) a++; 53 return a; // value of {a} escapes. 54 // can only remove the loop with induction variable analysis. 55} 56 57function loop5() { 58 var a = new Int32Array(4), sum = 0; 59 for (var i = 0; i < a.length; i++) { 60 sum += a[i]; 61 } 62 return sum; // {sum} escapes. 63 // can only remove the loop by figuring out that all elements of {a} are 0. 64} 65 66function loop6(a) { 67 for (var i = 0; i < a; i++) ; // implicit a.valueOf(). 68 // can only remove the loop by guarding on the type of a. 69} 70 71function loop7(a) { 72 for (var i = 0; i < 10; i++) a.toString(); // unknown side-effect on a. 73 // can only remove the loop by guarding on the type of a. 74} 75 76function loop8(a) { 77 for (var i = 0; i < 10; i++) a.valueOf(); // unknown side-effect on a. 78 // can only remove the loop by guarding on the type of a. 79} 80 81var no_params_loops = [loop1, loop2, loop3, loop4, loop5, loop6]; 82var params_loops = [loop6, loop7, loop8]; 83 84for (var i = 0; i < no_params_loops.length; i++) { 85 var f = no_params_loops[i]; 86 f(); 87 f(); 88 f(); 89 %OptimizeFunctionOnNextCall(f); 90 f(); 91} 92 93for (var i = 0; i < params_loops.length; i++) { 94 var f = params_loops[i]; 95 f(3); 96 f(7); 97 f(11); 98 %OptimizeFunctionOnNextCall(f); 99 f(9); 100} 101