regress-2250.js revision b8a8cc1952d61a2f3a2568848933943a543b5d3e
13ef787dbeca8a5fb1086949cda830dccee07bfbdBen Murdoch// Copyright 2012 the V8 project authors. All rights reserved. 2a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// Redistribution and use in source and binary forms, with or without 3a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// modification, are permitted provided that the following conditions are 4a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// met: 5a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// 6a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// * Redistributions of source code must retain the above copyright 7a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// notice, this list of conditions and the following disclaimer. 8a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// * Redistributions in binary form must reproduce the above 9a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// copyright notice, this list of conditions and the following 10a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// disclaimer in the documentation and/or other materials provided 11a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// with the distribution. 12a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// * Neither the name of Google Inc. nor the names of its 13a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// contributors may be used to endorse or promote products derived 14a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// from this software without specific prior written permission. 15a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// 16a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 28b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// Flags: --allow-natives-syntax 29a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 30b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// The original problem from the bug: In the example below SMI check for b 31b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// generated for inlining of equals invocation (marked with (*)) will be hoisted 32b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// out of the loop across the typeof b === "object" condition and cause an 33b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// immediate deopt. Another problem here is that no matter how many time we 34b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// deopt and reopt we will continue to produce the wrong code. 35b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// 36b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// The fix is to notice when a deopt and subsequent reopt doesn't find 37b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// additional type information, indicating that optimistic LICM should be 38b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// disabled during compilation. 39b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch 40b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochfunction eq(a, b) { 41b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch if (typeof b === "object") { 42b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch return b.equals(a); // (*) 43b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch } 44b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch return a === b; 45b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch} 46a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 47b8a8cc1952d61a2f3a2568848933943a543b5d3eBen MurdochObject.prototype.equals = function (other) { 48b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch return (this === other); 49b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch}; 50a7e24c173cf37484693b9abb38e494fa7bd7baebSteve Block 51b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochfunction test() { 52b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch for (var i = 0; !eq(i, 10); i++) 53b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch ; 54b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch} 553ef787dbeca8a5fb1086949cda830dccee07bfbdBen Murdoch 56b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdocheq({}, {}); 57b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdocheq({}, {}); 58b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdocheq(1, 1); 59b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdocheq(1, 1); 60b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochtest(); 61b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch%OptimizeFunctionOnNextCall(test); 62b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochtest(); 63b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch%OptimizeFunctionOnNextCall(test); 64b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// Second compilation should have noticed that LICM wasn't a good idea, and now 65b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdoch// function should no longer deopt when called. 66b8a8cc1952d61a2f3a2568848933943a543b5d3eBen Murdochtest(); 67b8a8cc1952d61a2f3a2568848933943a543b5d3eBen MurdochassertOptimized(test); 68