/* * Copyright (C) 2014, 2015 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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. */ #include "config.h" #include "DFGMayExit.h" #if ENABLE(DFG_JIT) #include "DFGGraph.h" #include "DFGNode.h" #include "Operations.h" namespace JSC { namespace DFG { namespace { class EdgeMayExit { public: EdgeMayExit() : m_result(false) { } void operator()(Node*, Edge edge) { if (edge.willHaveCheck()) { m_result = true; return; } switch (edge.useKind()) { // These are shady because nodes that have these use kinds will typically exit for // unrelated reasons. For example CompareEq doesn't usually exit, but if it uses ObjectUse // then it will. case ObjectUse: case ObjectOrOtherUse: m_result = true; break; // These are shady because they check the structure even if the type of the child node // passes the StringObject type filter. case StringObjectUse: case StringOrStringObjectUse: m_result = true; break; default: break; } } bool result() const { return m_result; } private: bool m_result; }; } // anonymous namespace bool mayExit(Graph& graph, Node* node) { switch (node->op()) { // This is a carefully curated list of nodes that definitely do not exit. We try to be very // conservative when maintaining this list, because adding new node types to it doesn't // generally make things a lot better but it might introduce insanely subtle bugs. case SetArgument: case JSConstant: case DoubleConstant: case Int52Constant: case MovHint: case SetLocal: case Flush: case Phantom: case Check: case GetLocal: case LoopHint: case Phi: case Upsilon: case ZombieHint: case BottomValue: case PutHint: case PhantomNewObject: case PutStack: case KillStack: case GetStack: case GetCallee: case GetArgumentCount: case GetScope: case PhantomLocal: case CountExecution: case Jump: case Branch: case Unreachable: case DoubleRep: case Int52Rep: case ValueRep: break; default: // If in doubt, return true. return true; } EdgeMayExit functor; DFG_NODE_DO_TO_CHILDREN(graph, node, functor); return functor.result(); } } } // namespace JSC::DFG #endif // ENABLE(DFG_JIT)