/* * Copyright (C) 2014 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. */ #ifndef DFGStaticExecutionCountEstimationPhase_h #define DFGStaticExecutionCountEstimationPhase_h #if ENABLE(DFG_JIT) namespace JSC { namespace DFG { class Graph; // Estimate execution counts (branch execution counts, in particular) based on // presently available static information. This phase is important because // subsequent CFG transformations, such as OSR entrypoint creation, perturb our // ability to do accurate static estimations. Hence we lock in the estimates early. // Ideally, we would have dynamic information, but we don't right now, so this is as // good as it gets. // // It's worth noting that if we didn't have this phase, then the static estimation // would be perfomed by LLVM instead. It's worth trying to make this phase perform // the estimates using the same heuristics that LLVM would use. bool performStaticExecutionCountEstimation(Graph&); } } // namespace JSC::DFG #endif // ENABLE(DFG_JIT) #endif // DFGStaticExecutionCountEstimationPhase_h