dfg/DFGOSRExitCompiler.cpp

   1 /*
   2  * Copyright (C) 2011, 2012 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 "DFGCommon.h"
  33 #include "LinkBuffer.h"
  34 #include "Operations.h"
  35 #include "RepatchBuffer.h"
  36 #include <wtf/StringPrintStream.h>
  37
  38 namespace JSC { namespace DFG {
  39
  40 extern "C" {
  41
  42 void compileOSRExit(ExecState* exec)
  43 {
  44     SamplingRegion samplingRegion("DFG OSR Exit Compilation");
  45
  46     CodeBlock* codeBlock = exec->codeBlock();
  47
  48     ASSERT(codeBlock);
  49     ASSERT(codeBlock->getJITType() == JITCode::DFGJIT);
  50
  51     VM* vm = &exec->vm();
  52
  53     uint32_t exitIndex = vm->osrExitIndex;
  54     OSRExit& exit = codeBlock->osrExit(exitIndex);
  55
  56     // Make sure all code on our inline stack is JIT compiled. This is necessary since
  57     // we may opt to inline a code block even before it had ever been compiled by the
  58     // JIT, but our OSR exit infrastructure currently only works if the target of the
  59     // OSR exit is JIT code. This could be changed since there is nothing particularly
  60     // hard about doing an OSR exit into the interpreter, but for now this seems to make
  61     // sense in that if we're OSR exiting from inlined code of a DFG code block, then
  62     // probably it's a good sign that the thing we're exiting into is hot. Even more
  63     // interestingly, since the code was inlined, it may never otherwise get JIT
  64     // compiled since the act of inlining it may ensure that it otherwise never runs.
  65     for (CodeOrigin codeOrigin = exit.m_codeOrigin; codeOrigin.inlineCallFrame; codeOrigin = codeOrigin.inlineCallFrame->caller) {
  66         static_cast<FunctionExecutable*>(codeOrigin.inlineCallFrame->executable.get())
  67             ->baselineCodeBlockFor(codeOrigin.inlineCallFrame->isCall ? CodeForCall : CodeForConstruct)
  68             ->jitCompile(exec);
  69     }
  70
  71     // Compute the value recoveries.
  72     Operands<ValueRecovery> operands;
  73     codeBlock->variableEventStream().reconstruct(codeBlock, exit.m_codeOrigin, codeBlock->minifiedDFG(), exit.m_streamIndex, operands);
  74
  75     // There may be an override, for forward speculations.
  76     if (!!exit.m_valueRecoveryOverride) {
  77         operands.setOperand(
  78             exit.m_valueRecoveryOverride->operand, exit.m_valueRecoveryOverride->recovery);
  79     }
  80
  81     SpeculationRecovery* recovery = 0;
  82     if (exit.m_recoveryIndex)
  83         recovery = &codeBlock->speculationRecovery(exit.m_recoveryIndex - 1);
  84
  85 #if DFG_ENABLE(DEBUG_VERBOSE)
  86     dataLog(
  87         "Generating OSR exit #", exitIndex, " (seq#", exit.m_streamIndex,
  88         ", bc#", exit.m_codeOrigin.bytecodeIndex, ", ",
  89         exit.m_kind, ") for ", *codeBlock, ".\n");
  90 #endif
  91
  92     {
  93         CCallHelpers jit(vm, codeBlock);
  94         OSRExitCompiler exitCompiler(jit);
  95
  96         jit.jitAssertHasValidCallFrame();
  97
  98         if (vm->m_perBytecodeProfiler && codeBlock->compilation()) {
  99             Profiler::Database& database = *vm->m_perBytecodeProfiler;
 100             Profiler::Compilation* compilation = codeBlock->compilation();
 101
 102             Profiler::OSRExit* profilerExit = compilation->addOSRExit(
 103                 exitIndex, Profiler::OriginStack(database, codeBlock, exit.m_codeOrigin),
 104                 exit.m_kind,
 105                 exit.m_watchpointIndex != std::numeric_limits<unsigned>::max());
 106             jit.add64(CCallHelpers::TrustedImm32(1), CCallHelpers::AbsoluteAddress(profilerExit->counterAddress()));
 107         }
 108
 109         exitCompiler.compileExit(exit, operands, recovery);
 110
 111         LinkBuffer patchBuffer(*vm, &jit, codeBlock);
 112         exit.m_code = FINALIZE_CODE_IF(
 113             shouldShowDisassembly(),
 114             patchBuffer,
 115             ("DFG OSR exit #%u (bc#%u, %s) from %s",
 116                 exitIndex, exit.m_codeOrigin.bytecodeIndex,
 117                 exitKindToString(exit.m_kind), toCString(*codeBlock).data()));
 118     }
 119
 120     {
 121         RepatchBuffer repatchBuffer(codeBlock);
 122         repatchBuffer.relink(exit.codeLocationForRepatch(codeBlock), CodeLocationLabel(exit.m_code.code()));
 123     }
 124
 125     vm->osrExitJumpDestination = exit.m_code.code().executableAddress();
 126 }
 127
 128 } // extern "C"
 129
 130 void OSRExitCompiler::handleExitCounts(const OSRExit& exit)
 131 {
 132     m_jit.add32(AssemblyHelpers::TrustedImm32(1), AssemblyHelpers::AbsoluteAddress(&exit.m_count));
 133
 134     m_jit.move(AssemblyHelpers::TrustedImmPtr(m_jit.codeBlock()), GPRInfo::regT0);
 135
 136     AssemblyHelpers::Jump tooFewFails;
 137
 138     m_jit.load32(AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfOSRExitCounter()), GPRInfo::regT2);
 139     m_jit.add32(AssemblyHelpers::TrustedImm32(1), GPRInfo::regT2);
 140     m_jit.store32(GPRInfo::regT2, AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfOSRExitCounter()));
 141     m_jit.move(AssemblyHelpers::TrustedImmPtr(m_jit.baselineCodeBlock()), GPRInfo::regT0);
 142     tooFewFails = m_jit.branch32(AssemblyHelpers::BelowOrEqual, GPRInfo::regT2, AssemblyHelpers::TrustedImm32(m_jit.codeBlock()->exitCountThresholdForReoptimization()));
 143
 144     // Reoptimize as soon as possible.
 145 #if !NUMBER_OF_ARGUMENT_REGISTERS
 146     m_jit.poke(GPRInfo::regT0);
 147 #else
 148     m_jit.move(GPRInfo::regT0, GPRInfo::argumentGPR0);
 149     ASSERT(GPRInfo::argumentGPR0 != GPRInfo::regT1);
 150 #endif
 151     m_jit.move(AssemblyHelpers::TrustedImmPtr(bitwise_cast<void*>(triggerReoptimizationNow)), GPRInfo::regT1);
 152     m_jit.call(GPRInfo::regT1);
 153     AssemblyHelpers::Jump doneAdjusting = m_jit.jump();
 154
 155     tooFewFails.link(&m_jit);
 156
 157     // Adjust the execution counter such that the target is to only optimize after a while.
 158     int32_t activeThreshold =
 159         m_jit.baselineCodeBlock()->counterValueForOptimizeAfterLongWarmUp();
 160     int32_t targetValue = ExecutionCounter::applyMemoryUsageHeuristicsAndConvertToInt(
 161         activeThreshold, m_jit.baselineCodeBlock());
 162     int32_t clippedValue =
 163         ExecutionCounter::clippedThreshold(m_jit.codeBlock()->globalObject(), targetValue);
 164     m_jit.store32(AssemblyHelpers::TrustedImm32(-clippedValue), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecuteCounter()));
 165     m_jit.store32(AssemblyHelpers::TrustedImm32(activeThreshold), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecutionActiveThreshold()));
 166     m_jit.store32(AssemblyHelpers::TrustedImm32(ExecutionCounter::formattedTotalCount(clippedValue)), AssemblyHelpers::Address(GPRInfo::regT0, CodeBlock::offsetOfJITExecutionTotalCount()));
 167
 168     doneAdjusting.link(&m_jit);
 169 }
 170
 171 } } // namespace JSC::DFG
 172
 173 #endif // ENABLE(DFG_JIT)