dfg/DFGOSRExit.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 "DFGOSRExit.h"
  28
  29 #if ENABLE(DFG_JIT)
  30
  31 #include "DFGAssemblyHelpers.h"
  32 #include "DFGSpeculativeJIT.h"
  33 #include "JSCellInlines.h"
  34
  35 namespace JSC { namespace DFG {
  36
  37 OSRExit::OSRExit(ExitKind kind, JSValueSource jsValueSource, MethodOfGettingAValueProfile valueProfile, SpeculativeJIT* jit, unsigned streamIndex, unsigned recoveryIndex)
  38     : m_jsValueSource(jsValueSource)
  39     , m_valueProfile(valueProfile)
  40     , m_patchableCodeOffset(0)
  41     , m_codeOrigin(jit->m_codeOriginForOSR)
  42     , m_codeOriginForExitProfile(m_codeOrigin)
  43     , m_recoveryIndex(recoveryIndex)
  44     , m_watchpointIndex(std::numeric_limits<unsigned>::max())
  45     , m_kind(kind)
  46     , m_count(0)
  47     , m_streamIndex(streamIndex)
  48     , m_lastSetOperand(jit->m_lastSetOperand)
  49 {
  50     ASSERT(m_codeOrigin.isSet());
  51 }
  52
  53 void OSRExit::setPatchableCodeOffset(MacroAssembler::PatchableJump check)
  54 {
  55     m_patchableCodeOffset = check.m_jump.m_label.m_offset;
  56 }
  57
  58 MacroAssembler::Jump OSRExit::getPatchableCodeOffsetAsJump() const
  59 {
  60     return MacroAssembler::Jump(AssemblerLabel(m_patchableCodeOffset));
  61 }
  62
  63 CodeLocationJump OSRExit::codeLocationForRepatch(CodeBlock* dfgCodeBlock) const
  64 {
  65     return CodeLocationJump(dfgCodeBlock->getJITCode().dataAddressAtOffset(m_patchableCodeOffset));
  66 }
  67
  68 void OSRExit::correctJump(LinkBuffer& linkBuffer)
  69 {
  70     MacroAssembler::Label label;
  71     label.m_label.m_offset = m_patchableCodeOffset;
  72     m_patchableCodeOffset = linkBuffer.offsetOf(label);
  73 }
  74
  75 bool OSRExit::considerAddingAsFrequentExitSiteSlow(CodeBlock* profiledCodeBlock)
  76 {
  77     FrequentExitSite exitSite;
  78
  79     if (m_kind == ArgumentsEscaped) {
  80         // Count this one globally. It doesn't matter where in the code block the arguments excaped;
  81         // the fact that they did is not associated with any particular instruction.
  82         exitSite = FrequentExitSite(m_kind);
  83     } else
  84         exitSite = FrequentExitSite(m_codeOriginForExitProfile.bytecodeIndex, m_kind);
  85
  86     return baselineCodeBlockForOriginAndBaselineCodeBlock(m_codeOriginForExitProfile, profiledCodeBlock)->addFrequentExitSite(exitSite);
  87 }
  88
  89 } } // namespace JSC::DFG
  90
  91 #endif // ENABLE(DFG_JIT)