ftl/FTLOSREntry.cpp

   1 /*
   2  * Copyright (C) 2013, 2014 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 "FTLOSREntry.h"
  28
  29 #include "CallFrame.h"
  30 #include "CodeBlock.h"
  31 #include "DFGJITCode.h"
  32 #include "FTLForOSREntryJITCode.h"
  33 #include "JSStackInlines.h"
  34 #include "OperandsInlines.h"
  35 #include "JSCInlines.h"
  36
  37 #if ENABLE(FTL_JIT)
  38
  39 namespace JSC { namespace FTL {
  40
  41 void* prepareOSREntry(
  42     ExecState* exec, CodeBlock* dfgCodeBlock, CodeBlock* entryCodeBlock,
  43     unsigned bytecodeIndex, unsigned streamIndex)
  44 {
  45     VM& vm = exec->vm();
  46     CodeBlock* baseline = dfgCodeBlock->baselineVersion();
  47     ExecutableBase* executable = dfgCodeBlock->ownerExecutable();
  48     DFG::JITCode* dfgCode = dfgCodeBlock->jitCode()->dfg();
  49     ForOSREntryJITCode* entryCode = entryCodeBlock->jitCode()->ftlForOSREntry();
  50
  51     if (Options::verboseOSR()) {
  52         dataLog(
  53             "FTL OSR from ", *dfgCodeBlock, " to ", *entryCodeBlock, " at bc#",
  54             bytecodeIndex, ".\n");
  55     }
  56
  57     if (bytecodeIndex)
  58         jsCast<ScriptExecutable*>(executable)->setDidTryToEnterInLoop(true);
  59
  60     if (bytecodeIndex != entryCode->bytecodeIndex()) {
  61         if (Options::verboseOSR())
  62             dataLog("    OSR failed because we don't have an entrypoint for bc#", bytecodeIndex, "; ours is for bc#", entryCode->bytecodeIndex(), "\n");
  63         return 0;
  64     }
  65
  66     Operands<JSValue> values;
  67     dfgCode->reconstruct(
  68         exec, dfgCodeBlock, CodeOrigin(bytecodeIndex), streamIndex, values);
  69
  70     if (Options::verboseOSR())
  71         dataLog("    Values at entry: ", values, "\n");
  72
  73     for (int argument = values.numberOfArguments(); argument--;) {
  74         JSValue valueOnStack = exec->r(virtualRegisterForArgument(argument).offset()).jsValue();
  75         JSValue reconstructedValue = values.argument(argument);
  76         if (valueOnStack == reconstructedValue || !argument)
  77             continue;
  78         dataLog("Mismatch between reconstructed values and the the value on the stack for argument arg", argument, " for ", *entryCodeBlock, " at bc#", bytecodeIndex, ":\n");
  79         dataLog("    Value on stack: ", valueOnStack, "\n");
  80         dataLog("    Reconstructed value: ", reconstructedValue, "\n");
  81         RELEASE_ASSERT_NOT_REACHED();
  82     }
  83
  84     RELEASE_ASSERT(
  85         static_cast<int>(values.numberOfLocals()) == baseline->m_numCalleeRegisters);
  86
  87     EncodedJSValue* scratch = static_cast<EncodedJSValue*>(
  88         entryCode->entryBuffer()->dataBuffer());
  89
  90     for (int local = values.numberOfLocals(); local--;)
  91         scratch[local] = JSValue::encode(values.local(local));
  92
  93     int stackFrameSize = entryCode->common.requiredRegisterCountForExecutionAndExit();
  94     if (!vm.interpreter->stack().ensureCapacityFor(&exec->registers()[virtualRegisterForLocal(stackFrameSize - 1).offset()])) {
  95         if (Options::verboseOSR())
  96             dataLog("    OSR failed because stack growth failed.\n");
  97         return 0;
  98     }
  99
 100     exec->setCodeBlock(entryCodeBlock);
 101
 102     void* result = entryCode->addressForCall(
 103         vm, executable, ArityCheckNotRequired,
 104         RegisterPreservationNotRequired).executableAddress();
 105     if (Options::verboseOSR())
 106         dataLog("    Entry will succeed, going to address", RawPointer(result), "\n");
 107
 108     return result;
 109 }
 110
 111 } } // namespace JSC::FTL
 112
 113 #endif // ENABLE(FTL_JIT)
 114
 115