// Copyright 2011 the V8 project authors. All rights reserved. // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following // disclaimer in the documentation and/or other materials provided // with the distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived // from this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. // Flags: --allow-natives-syntax --noalways-opt --opt // It's nice to run this in other browsers too. var standalone = false; if (standalone) { assertTrue = function(val) { if (val != true) { print("FAILURE"); } } assertFalse = function(val) { if (val != false) { print("FAILURE"); } } assertEquals = function(expected, val) { if (expected !== val) { print("FAILURE"); } } empty_func = function(name) { } assertUnoptimized = empty_func; assertOptimized = empty_func; optimize = empty_func; clearFunctionTypeFeedback = empty_func; deoptimizeFunction = empty_func; } else { optimize = function(name) { %OptimizeFunctionOnNextCall(name); } clearFunctionTypeFeedback = function(name) { %ClearFunctionFeedback(name); } deoptimizeFunction = function(name) { %DeoptimizeFunction(name); } } function base_getter_test(create_func) { var calls = 0; // Testcase: setter in prototype chain foo = function(a) { var x = a[0]; return x + 3; } var a = create_func(); var ap = []; ap.__defineGetter__(0, function() { calls++; return 0; }); foo(a); assertUnoptimized(foo); // Smi and Double elements transition the KeyedLoadIC to Generic state // here, because they miss twice with the same map when loading the hole. // For HOLEY_ELEMENTS, however, the IC knows how to convert the hole // to undefined if the prototype is the original array prototype, so it // stays monomorphic for now... foo(a); foo(a); delete a[0]; assertEquals(0, calls); a.__proto__ = ap; // ...and later becomes polymorphic when it sees a second map. Optimized // code will therefore inline the elements access, and deopt right away // when it loads the hole from index [0]. // Possible solutions: // - remove the convert_hole_to_undefined flag from the IC, to force it // into generic state for all elements kinds. Cost: slower ICs in code // that doesn't get optimized. // - teach Turbofan about the same trick: for holey elements with the // original array prototype, convert hole to undefined inline. Cost: // larger optimized code size, because the loads for different maps with // the same elements kind can no longer be consolidated if they handle // the hole differently. // - call "foo" twice after setting a.__proto__ and before optimizing it; // this is the simplest fix so let's do that for now. foo(a); assertEquals(1, calls); foo(a); assertEquals(2, calls); optimize(foo); foo(a); assertEquals(3, calls); assertOptimized(foo); // Testcase: getter "deep" in prototype chain. clearFunctionTypeFeedback(foo); deoptimizeFunction(foo); clearFunctionTypeFeedback(foo); calls = 0; a = create_func(); var ap2 = []; a.__proto__ = ap2; foo(a); foo(a); foo(a); delete a[0]; assertEquals(0, calls); ap2.__proto__ = ap; // "sneak" in a callback. // The sneak case should be caught by unoptimized code too. assertUnoptimized(foo); foo(a); foo(a); foo(a); assertEquals(3, calls); // Testcase: getter added after optimization (feedback is monomorphic) clearFunctionTypeFeedback(foo); deoptimizeFunction(foo); clearFunctionTypeFeedback(foo); calls = 0; a = create_func(); ap2 = []; a.__proto__ = ap2; foo(a); foo(a); foo(a); optimize(foo); foo(a); assertOptimized(foo); delete a[0]; ap2.__proto__ = ap; foo(a); assertOptimized(foo); // getters don't require deopt on shape change. assertEquals(1, calls); // Testcase: adding additional getters to a prototype chain that already has // one shouldn't deopt anything. clearFunctionTypeFeedback(foo); calls = 0; a = create_func(); a.__proto__ = ap2; bar = function(a) { return a[3] + 600; } bar(a); bar(a); bar(a); optimize(bar); bar(a); assertOptimized(bar); assertEquals(0, calls); delete a[3]; ap2.__defineGetter__(3, function() { calls++; return 0; }); bar(a); assertOptimized(bar); assertEquals(1, calls); // Reset the state of foo and bar. clearFunctionTypeFeedback(foo); deoptimizeFunction(foo); clearFunctionTypeFeedback(foo); clearFunctionTypeFeedback(bar); deoptimizeFunction(bar); clearFunctionTypeFeedback(bar); } // Verify that map transitions don't confuse us. create_func_smi = function() { return [,,,,,,5]; } create_func_double = function() { return [,,,,,,5.5]; } create_func_fast = function() { return [,,,,,,true]; } var cf = [create_func_smi, create_func_double, create_func_fast]; for(var c = 0; c < cf.length; c++) { base_getter_test(cf[c]); } // A special test for LoadKeyedHoleMode. Ensure that optimized is generated // which sets ALLOW_RETURN_HOLE, then add a setter on the prototype that should // cause the function to deoptimize. var a = [3.5,,,3.5]; fun = function(a) { return a[0] + 5.5; } fun(a); fun(a); fun(a); // should have a monomorphic KeyedLoadIC. optimize(fun); fun(a); assertOptimized(fun); // returning undefined shouldn't phase us. delete a[0]; fun(a); assertOptimized(fun); // but messing up the prototype chain will. a.__proto__ = []; fun(a); assertUnoptimized(fun); // Construct a non-trivial prototype chain. var a = [3.5,,,,3.5]; var ap = [,,3.5]; ap.__proto__ = a.__proto__; a.__proto__ = ap; fun(a); optimize(fun); fun(a); assertOptimized(fun); var calls = 0; delete a[0]; ap.__defineGetter__(0, function() { calls++; return 0; }); fun(a); assertEquals(1, calls); assertUnoptimized(fun);