dfg/DFGOSRExitCompiler.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 "DFGOSRExitCompiler.h"
  28
  29 #if ENABLE(DFG_JIT)
  30
  31 #include "CallFrame.h"
  32 #include "LinkBuffer.h"
  33 #include "RepatchBuffer.h"
  34
  35 namespace JSC { namespace DFG {
  36
  37 extern "C" {
  38
  39 void compileOSRExit(ExecState* exec)
  40 {
  41     CodeBlock* codeBlock = exec->codeBlock();
  42
  43     ASSERT(codeBlock);
  44     ASSERT(codeBlock->getJITType() == JITCode::DFGJIT);
  45
  46     JSGlobalData* globalData = &exec->globalData();
  47
  48     uint32_t exitIndex = globalData->osrExitIndex;
  49     OSRExit& exit = codeBlock->osrExit(exitIndex);
  50
  51     // Make sure all code on our inline stack is JIT compiled. This is necessary since
  52     // we may opt to inline a code block even before it had ever been compiled by the
  53     // JIT, but our OSR exit infrastructure currently only works if the target of the
  54     // OSR exit is JIT code. This could be changed since there is nothing particularly
  55     // hard about doing an OSR exit into the interpreter, but for now this seems to make
  56     // sense in that if we're OSR exiting from inlined code of a DFG code block, then
  57     // probably it's a good sign that the thing we're exiting into is hot. Even more
  58     // interestingly, since the code was inlined, it may never otherwise get JIT
  59     // compiled since the act of inlining it may ensure that it otherwise never runs.
  60     for (CodeOrigin codeOrigin = exit.m_codeOrigin; codeOrigin.inlineCallFrame; codeOrigin = codeOrigin.inlineCallFrame->caller) {
  61         static_cast<FunctionExecutable*>(codeOrigin.inlineCallFrame->executable.get())
  62             ->baselineCodeBlockFor(codeOrigin.inlineCallFrame->isCall ? CodeForCall : CodeForConstruct)
  63             ->jitCompile(*globalData);
  64     }
  65
  66     SpeculationRecovery* recovery = 0;
  67     if (exit.m_recoveryIndex)
  68         recovery = &codeBlock->speculationRecovery(exit.m_recoveryIndex - 1);
  69
  70 #if DFG_ENABLE(DEBUG_VERBOSE)
  71     dataLog("Generating OSR exit #%u (bc#%u, @%u, %s) for code block %p.\n", exitIndex, exit.m_codeOrigin.bytecodeIndex, exit.m_nodeIndex, exitKindToString(exit.m_kind), codeBlock);
  72 #endif
  73
  74     {
  75         AssemblyHelpers jit(globalData, codeBlock);
  76         OSRExitCompiler exitCompiler(jit);
  77
  78         jit.jitAssertHasValidCallFrame();
  79         exitCompiler.compileExit(exit, recovery);
  80
  81         LinkBuffer patchBuffer(*globalData, &jit, codeBlock);
  82         exit.m_code = patchBuffer.finalizeCode();
  83
  84 #if DFG_ENABLE(DEBUG_VERBOSE)
  85         dataLog("OSR exit code at [%p, %p).\n", patchBuffer.debugAddress(), static_cast<char*>(patchBuffer.debugAddress()) + patchBuffer.debugSize());
  86 #endif
  87     }
  88
  89     {
  90         RepatchBuffer repatchBuffer(codeBlock);
  91         repatchBuffer.relink(exit.m_check.codeLocationForRepatch(codeBlock), CodeLocationLabel(exit.m_code.code()));
  92     }
  93
  94     globalData->osrExitJumpDestination = exit.m_code.code().executableAddress();
  95 }
  96
  97 } // extern "C"
  98
  99 void OSRExitCompiler::handleExitCounts(const OSRExit& exit)
 100 {
 101     m_jit.add32(AssemblyHelpers::TrustedImm32(1), AssemblyHelpers::AbsoluteAddress(&exit.m_count));
 102
 103     m_jit.move(AssemblyHelpers::TrustedImmPtr(m_jit.codeBlock()), GPRInfo::regT0);
 104
 105     AssemblyHelpers::JumpList tooFewFails;
 106
 107     if (exit.m_kind == InadequateCoverage) {
 108         // Proceed based on the assumption that we can profitably optimize this code once
 109         // it has executed enough times.
 110
 111         m_jit.load32(AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfForcedOSRExitCounter()), GPRInfo::regT2);
 112         m_jit.load32(AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfSpeculativeSuccessCounter()), GPRInfo::regT1);
 113         m_jit.add32(AssemblyHelpers::TrustedImm32(1), GPRInfo::regT2);
 114         m_jit.add32(AssemblyHelpers::TrustedImm32(-1), GPRInfo::regT1);
 115         m_jit.store32(GPRInfo::regT2, AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfForcedOSRExitCounter()));
 116         m_jit.store32(GPRInfo::regT1, AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfSpeculativeSuccessCounter()));
 117
 118         tooFewFails.append(m_jit.branch32(AssemblyHelpers::BelowOrEqual, GPRInfo::regT2, AssemblyHelpers::TrustedImm32(Options::forcedOSRExitCountForReoptimization)));
 119     } else {
 120         // Proceed based on the assumption that we can handle these exits so long as they
 121         // don't get too frequent.
 122
 123         m_jit.load32(AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfSpeculativeFailCounter()), GPRInfo::regT2);
 124         m_jit.load32(AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfSpeculativeSuccessCounter()), GPRInfo::regT1);
 125         m_jit.add32(AssemblyHelpers::TrustedImm32(1), GPRInfo::regT2);
 126         m_jit.add32(AssemblyHelpers::TrustedImm32(-1), GPRInfo::regT1);
 127         m_jit.store32(GPRInfo::regT2, AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfSpeculativeFailCounter()));
 128         m_jit.store32(GPRInfo::regT1, AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfSpeculativeSuccessCounter()));
 129
 130         m_jit.move(AssemblyHelpers::TrustedImmPtr(m_jit.baselineCodeBlock()), GPRInfo::regT0);
 131
 132         tooFewFails.append(m_jit.branch32(AssemblyHelpers::BelowOrEqual, GPRInfo::regT2, AssemblyHelpers::TrustedImm32(m_jit.codeBlock()->largeFailCountThreshold())));
 133         m_jit.mul32(AssemblyHelpers::TrustedImm32(Options::desiredSpeculativeSuccessFailRatio), GPRInfo::regT2, GPRInfo::regT2);
 134
 135         tooFewFails.append(m_jit.branch32(AssemblyHelpers::BelowOrEqual, GPRInfo::regT2, GPRInfo::regT1));
 136     }
 137
 138     // Reoptimize as soon as possible.
 139     m_jit.store32(AssemblyHelpers::TrustedImm32(0), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecuteCounter()));
 140     m_jit.store32(AssemblyHelpers::TrustedImm32(0), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecutionActiveThreshold()));
 141     AssemblyHelpers::Jump doneAdjusting = m_jit.jump();
 142
 143     tooFewFails.link(&m_jit);
 144
 145     // Adjust the execution counter such that the target is to only optimize after a while.
 146     int32_t targetValue =
 147         ExecutionCounter::applyMemoryUsageHeuristicsAndConvertToInt(
 148             m_jit.baselineCodeBlock()->counterValueForOptimizeAfterLongWarmUp(),
 149             m_jit.baselineCodeBlock());
 150     m_jit.store32(AssemblyHelpers::TrustedImm32(-targetValue), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecuteCounter()));
 151     m_jit.store32(AssemblyHelpers::TrustedImm32(targetValue), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecutionActiveThreshold()));
 152     m_jit.store32(AssemblyHelpers::TrustedImm32(ExecutionCounter::formattedTotalCount(targetValue)), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecutionTotalCount()));
 153
 154     doneAdjusting.link(&m_jit);
 155 }
 156
 157 } } // namespace JSC::DFG
 158
 159 #endif // ENABLE(DFG_JIT)