bytecode/DFGExitProfile.cpp

   1 /*
   2  * Copyright (C) 2011 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "DFGExitProfile.h"
  28
  29 #if ENABLE(DFG_JIT)
  30
  31 #include <wtf/PassOwnPtr.h>
  32
  33 namespace JSC { namespace DFG {
  34
  35 ExitProfile::ExitProfile() { }
  36 ExitProfile::~ExitProfile() { }
  37
  38 bool ExitProfile::add(const ConcurrentJITLocker&, const FrequentExitSite& site)
  39 {
  40     ASSERT(site.jitType() != ExitFromAnything);
  41
  42     // If we've never seen any frequent exits then create the list and put this site
  43     // into it.
  44     if (!m_frequentExitSites) {
  45         m_frequentExitSites = adoptPtr(new Vector<FrequentExitSite>());
  46         m_frequentExitSites->append(site);
  47         return true;
  48     }
  49
  50     // Don't add it if it's already there. This is O(n), but that's OK, because we
  51     // know that the total number of places where code exits tends to not be large,
  52     // and this code is only used when recompilation is triggered.
  53     for (unsigned i = 0; i < m_frequentExitSites->size(); ++i) {
  54         if (m_frequentExitSites->at(i) == site)
  55             return false;
  56     }
  57
  58     m_frequentExitSites->append(site);
  59     return true;
  60 }
  61
  62 Vector<FrequentExitSite> ExitProfile::exitSitesFor(unsigned bytecodeIndex)
  63 {
  64     Vector<FrequentExitSite> result;
  65
  66     if (!m_frequentExitSites)
  67         return result;
  68
  69     for (unsigned i = 0; i < m_frequentExitSites->size(); ++i) {
  70         if (m_frequentExitSites->at(i).bytecodeOffset() == bytecodeIndex)
  71             result.append(m_frequentExitSites->at(i));
  72     }
  73
  74     return result;
  75 }
  76
  77 bool ExitProfile::hasExitSite(const ConcurrentJITLocker&, const FrequentExitSite& site) const
  78 {
  79     if (!m_frequentExitSites)
  80         return false;
  81
  82     for (unsigned i = m_frequentExitSites->size(); i--;) {
  83         if (site.subsumes(m_frequentExitSites->at(i)))
  84             return true;
  85     }
  86     return false;
  87 }
  88
  89 QueryableExitProfile::QueryableExitProfile() { }
  90 QueryableExitProfile::~QueryableExitProfile() { }
  91
  92 void QueryableExitProfile::initialize(const ConcurrentJITLocker&, const ExitProfile& profile)
  93 {
  94     if (!profile.m_frequentExitSites)
  95         return;
  96
  97     for (unsigned i = 0; i < profile.m_frequentExitSites->size(); ++i)
  98         m_frequentExitSites.add(profile.m_frequentExitSites->at(i));
  99 }
 100
 101 } } // namespace JSC::DFG
 102
 103 #endif