dfg/DFGOSRExitCompiler.cpp

   1 /*
   2  * Copyright (C) 2011, 2012, 2013 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 "DFGJITCode.h"
  34 #include "DFGOSRExitPreparation.h"
  35 #include "LinkBuffer.h"
  36 #include "OperandsInlines.h"
  37 #include "JSCInlines.h"
  38 #include "RepatchBuffer.h"
  39 #include <wtf/StringPrintStream.h>
  40
  41 namespace JSC { namespace DFG {
  42
  43 extern "C" {
  44
  45 void compileOSRExit(ExecState* exec)
  46 {
  47     SamplingRegion samplingRegion("DFG OSR Exit Compilation");
  48
  49     CodeBlock* codeBlock = exec->codeBlock();
  50
  51     ASSERT(codeBlock);
  52     ASSERT(codeBlock->jitType() == JITCode::DFGJIT);
  53
  54     VM* vm = &exec->vm();
  55
  56     // It's sort of preferable that we don't GC while in here. Anyways, doing so wouldn't
  57     // really be profitable.
  58     DeferGCForAWhile deferGC(vm->heap);
  59
  60     uint32_t exitIndex = vm->osrExitIndex;
  61     OSRExit& exit = codeBlock->jitCode()->dfg()->osrExit[exitIndex];
  62
  63     prepareCodeOriginForOSRExit(exec, exit.m_codeOrigin);
  64
  65     // Compute the value recoveries.
  66     Operands<ValueRecovery> operands;
  67     codeBlock->jitCode()->dfg()->variableEventStream.reconstruct(codeBlock, exit.m_codeOrigin, codeBlock->jitCode()->dfg()->minifiedDFG, exit.m_streamIndex, operands);
  68
  69     // There may be an override, for forward speculations.
  70     if (!!exit.m_valueRecoveryOverride) {
  71         operands.setOperand(
  72             exit.m_valueRecoveryOverride->operand, exit.m_valueRecoveryOverride->recovery);
  73     }
  74
  75     SpeculationRecovery* recovery = 0;
  76     if (exit.m_recoveryIndex != UINT_MAX)
  77         recovery = &codeBlock->jitCode()->dfg()->speculationRecovery[exit.m_recoveryIndex];
  78
  79     {
  80         CCallHelpers jit(vm, codeBlock);
  81         OSRExitCompiler exitCompiler(jit);
  82
  83         jit.jitAssertHasValidCallFrame();
  84
  85         if (vm->m_perBytecodeProfiler && codeBlock->jitCode()->dfgCommon()->compilation) {
  86             Profiler::Database& database = *vm->m_perBytecodeProfiler;
  87             Profiler::Compilation* compilation = codeBlock->jitCode()->dfgCommon()->compilation.get();
  88
  89             Profiler::OSRExit* profilerExit = compilation->addOSRExit(
  90                 exitIndex, Profiler::OriginStack(database, codeBlock, exit.m_codeOrigin),
  91                 exit.m_kind, isWatchpoint(exit.m_kind));
  92             jit.add64(CCallHelpers::TrustedImm32(1), CCallHelpers::AbsoluteAddress(profilerExit->counterAddress()));
  93         }
  94
  95         exitCompiler.compileExit(exit, operands, recovery);
  96
  97         LinkBuffer patchBuffer(*vm, jit, codeBlock);
  98         exit.m_code = FINALIZE_CODE_IF(
  99             shouldShowDisassembly() || Options::verboseOSR(),
 100             patchBuffer,
 101             ("DFG OSR exit #%u (%s, %s) from %s, with operands = %s",
 102                 exitIndex, toCString(exit.m_codeOrigin).data(),
 103                 exitKindToString(exit.m_kind), toCString(*codeBlock).data(),
 104                 toCString(ignoringContext<DumpContext>(operands)).data()));
 105     }
 106
 107     {
 108         RepatchBuffer repatchBuffer(codeBlock);
 109         repatchBuffer.relink(exit.codeLocationForRepatch(codeBlock), CodeLocationLabel(exit.m_code.code()));
 110     }
 111
 112     vm->osrExitJumpDestination = exit.m_code.code().executableAddress();
 113 }
 114
 115 } // extern "C"
 116
 117 } } // namespace JSC::DFG
 118
 119 #endif // ENABLE(DFG_JIT)