CodeBlock compilation and installation should be simplified and rationalized
authorfpizlo@apple.com <fpizlo@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>
Thu, 29 Aug 2013 18:25:36 +0000 (18:25 +0000)
committerfpizlo@apple.com <fpizlo@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>
Thu, 29 Aug 2013 18:25:36 +0000 (18:25 +0000)
commitae4336ada6d744b9c6b001b4e2df9b770b37067b
tree26c141c325a4fd76ea44e41cd2876184cd76ab37
parent546114aa97c05913b36b4ed2e31b7aca41bbe506
CodeBlock compilation and installation should be simplified and rationalized
https://bugs.webkit.org/show_bug.cgi?id=120326

Reviewed by Oliver Hunt.

Rolling r154804 back in after fixing no-LLInt build.

Previously Executable owned the code for generating JIT code; you always had
to go through Executable. But often you also had to go through CodeBlock,
because ScriptExecutable couldn't have virtual methods, but CodeBlock could.
So you'd ask CodeBlock to do something, which would dispatch through a
virtual method that would select the appropriate Executable subtype's method.
This all meant that the same code would often be duplicated, because most of
the work needed to compile something was identical regardless of code type.
But then we tried to fix this, by having templatized helpers in
ExecutionHarness.h and JITDriver.h. The result was that if you wanted to find
out what happened when you asked for something to be compiled, you'd go on a
wild ride that started with CodeBlock, touched upon Executable, and then
ricocheted into either ExecutionHarness or JITDriver (likely both).

Another awkwardness was that for concurrent compiles, the DFG::Worklist had
super-special inside knowledge of what JITStubs.cpp's cti_optimize would have
done once the compilation finished.

Also, most of the DFG JIT drivers assumed that they couldn't install the
JITCode into the CodeBlock directly - instead they would return it via a
reference, which happened to be a reference to the JITCode pointer in
Executable. This was super weird.

Finally, there was no notion of compiling code into a special CodeBlock that
wasn't used for handling calls into an Executable. I'd like this for FTL OSR
entry.

This patch solves these problems by reducing all of that complexity into just
three primitives:

- Executable::newCodeBlock(). This gives you a new code block, either for call
  or for construct, and either to serve as the baseline code or the optimized
  code. The new code block is then owned by the caller; Executable doesn't
  register it anywhere. The new code block has no JITCode and isn't callable,
  but it has all of the bytecode.

- CodeBlock::prepareForExecution(). This takes the CodeBlock's bytecode and
  produces a JITCode, and then installs the JITCode into the CodeBlock. This
  method takes a JITType, and always compiles with that JIT. If you ask for
  JITCode::InterpreterThunk then you'll get JITCode that just points to the
  LLInt entrypoints. Once this returns, it is possible to call into the
  CodeBlock if you do so manually - but the Executable still won't know about
  it so JS calls to that Executable will still be routed to whatever CodeBlock
  is associated with the Executable.

- Executable::installCode(). This takes a CodeBlock and makes it the code-for-
  entry for that Executable. This involves unlinking the Executable's last
  CodeBlock, if there was one. This also tells the GC about any effect on
  memory usage and does a bunch of weird data structure rewiring, since
  Executable caches some of CodeBlock's fields for the benefit of virtual call
  fast paths.

This functionality is then wrapped around three convenience methods:

- Executable::prepareForExecution(). If there is no code block for that
  Executable, then one is created (newCodeBlock()), compiled
  (CodeBlock::prepareForExecution()) and installed (installCode()).

- CodeBlock::newReplacement(). Asks the Executable for a new CodeBlock that
  can serve as an optimized replacement of the current one.

- CodeBlock::install(). Asks the Executable to install this code block.

This patch allows me to kill *a lot* of code and to remove a lot of
specializations for functions vs. not-functions, and a lot of places where we
pass around JITCode references and such. ExecutionHarness and JITDriver are
both gone. Overall this patch has more red than green.

It also allows me to work on FTL OSR entry and tier-up:

- FTL tier-up: this will involve DFGOperations.cpp asking the DFG::Worklist
  to do some compilation, but it will require the DFG::Worklist to do
  something different than what JITStubs.cpp would want, once the compilation
  finishes. This patch introduces a callback mechanism for that purpose.

- FTL OSR entry: this will involve creating a special auto-jettisoned
  CodeBlock that is used only for FTL OSR entry. The new set of primitives
  allows for this: Executable can vend you a fresh new CodeBlock, and you can
  ask that CodeBlock to compile itself with any JIT of your choosing. Or you
  can take that CodeBlock and compile it yourself. Previously the act of
  producing a CodeBlock-for-optimization and the act of compiling code for it
  were tightly coupled; now you can separate them and you can create such
  auto-jettisoned CodeBlocks that are used for a one-shot OSR entry.

* CMakeLists.txt:
* GNUmakefile.list.am:
* JavaScriptCore.vcxproj/JavaScriptCore.vcxproj:
* JavaScriptCore.xcodeproj/project.pbxproj:
* Target.pri:
* bytecode/CodeBlock.cpp:
(JSC::CodeBlock::unlinkIncomingCalls):
(JSC::CodeBlock::prepareForExecutionImpl):
(JSC::CodeBlock::prepareForExecution):
(JSC::CodeBlock::prepareForExecutionAsynchronously):
(JSC::CodeBlock::install):
(JSC::CodeBlock::newReplacement):
(JSC::FunctionCodeBlock::jettisonImpl):
* bytecode/CodeBlock.h:
(JSC::CodeBlock::hasBaselineJITProfiling):
* bytecode/DeferredCompilationCallback.cpp: Added.
(JSC::DeferredCompilationCallback::DeferredCompilationCallback):
(JSC::DeferredCompilationCallback::~DeferredCompilationCallback):
* bytecode/DeferredCompilationCallback.h: Added.
* dfg/DFGDriver.cpp:
(JSC::DFG::tryCompile):
* dfg/DFGDriver.h:
(JSC::DFG::tryCompile):
* dfg/DFGFailedFinalizer.cpp:
(JSC::DFG::FailedFinalizer::finalize):
(JSC::DFG::FailedFinalizer::finalizeFunction):
* dfg/DFGFailedFinalizer.h:
* dfg/DFGFinalizer.h:
* dfg/DFGJITFinalizer.cpp:
(JSC::DFG::JITFinalizer::finalize):
(JSC::DFG::JITFinalizer::finalizeFunction):
* dfg/DFGJITFinalizer.h:
* dfg/DFGOSRExitPreparation.cpp:
(JSC::DFG::prepareCodeOriginForOSRExit):
* dfg/DFGOperations.cpp:
* dfg/DFGPlan.cpp:
(JSC::DFG::Plan::Plan):
(JSC::DFG::Plan::compileInThreadImpl):
(JSC::DFG::Plan::notifyReady):
(JSC::DFG::Plan::finalizeWithoutNotifyingCallback):
(JSC::DFG::Plan::finalizeAndNotifyCallback):
* dfg/DFGPlan.h:
* dfg/DFGSpeculativeJIT32_64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* dfg/DFGWorklist.cpp:
(JSC::DFG::Worklist::completeAllReadyPlansForVM):
(JSC::DFG::Worklist::runThread):
* ftl/FTLJITFinalizer.cpp:
(JSC::FTL::JITFinalizer::finalize):
(JSC::FTL::JITFinalizer::finalizeFunction):
* ftl/FTLJITFinalizer.h:
* heap/Heap.h:
(JSC::Heap::isDeferred):
* interpreter/Interpreter.cpp:
(JSC::Interpreter::execute):
(JSC::Interpreter::executeCall):
(JSC::Interpreter::executeConstruct):
(JSC::Interpreter::prepareForRepeatCall):
* jit/JITDriver.h: Removed.
* jit/JITStubs.cpp:
(JSC::DEFINE_STUB_FUNCTION):
(JSC::jitCompileFor):
(JSC::lazyLinkFor):
* jit/JITToDFGDeferredCompilationCallback.cpp: Added.
(JSC::JITToDFGDeferredCompilationCallback::JITToDFGDeferredCompilationCallback):
(JSC::JITToDFGDeferredCompilationCallback::~JITToDFGDeferredCompilationCallback):
(JSC::JITToDFGDeferredCompilationCallback::create):
(JSC::JITToDFGDeferredCompilationCallback::compilationDidBecomeReadyAsynchronously):
(JSC::JITToDFGDeferredCompilationCallback::compilationDidComplete):
* jit/JITToDFGDeferredCompilationCallback.h: Added.
* llint/LLIntEntrypoints.cpp:
(JSC::LLInt::setFunctionEntrypoint):
(JSC::LLInt::setEvalEntrypoint):
(JSC::LLInt::setProgramEntrypoint):
* llint/LLIntEntrypoints.h:
* llint/LLIntSlowPaths.cpp:
(JSC::LLInt::jitCompileAndSetHeuristics):
(JSC::LLInt::setUpCall):
* runtime/ArrayPrototype.cpp:
(JSC::isNumericCompareFunction):
* runtime/CommonSlowPaths.cpp:
* runtime/CompilationResult.cpp:
(WTF::printInternal):
* runtime/CompilationResult.h:
* runtime/Executable.cpp:
(JSC::ScriptExecutable::installCode):
(JSC::ScriptExecutable::newCodeBlockFor):
(JSC::ScriptExecutable::newReplacementCodeBlockFor):
(JSC::ScriptExecutable::prepareForExecutionImpl):
* runtime/Executable.h:
(JSC::ExecutableBase::offsetOfJITCodeWithArityCheckFor):
(JSC::ExecutableBase::offsetOfNumParametersFor):
(JSC::ScriptExecutable::prepareForExecution):
(JSC::FunctionExecutable::jettisonOptimizedCodeFor):
* runtime/ExecutionHarness.h: Removed.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@154824 268f45cc-cd09-0410-ab3c-d52691b4dbfc
41 files changed:
Source/JavaScriptCore/CMakeLists.txt
Source/JavaScriptCore/ChangeLog
Source/JavaScriptCore/GNUmakefile.list.am
Source/JavaScriptCore/JavaScriptCore.vcxproj/JavaScriptCore.vcxproj
Source/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj
Source/JavaScriptCore/Target.pri
Source/JavaScriptCore/bytecode/CodeBlock.cpp
Source/JavaScriptCore/bytecode/CodeBlock.h
Source/JavaScriptCore/bytecode/DeferredCompilationCallback.cpp [new file with mode: 0644]
Source/JavaScriptCore/bytecode/DeferredCompilationCallback.h [new file with mode: 0644]
Source/JavaScriptCore/dfg/DFGDriver.cpp
Source/JavaScriptCore/dfg/DFGDriver.h
Source/JavaScriptCore/dfg/DFGFailedFinalizer.cpp
Source/JavaScriptCore/dfg/DFGFailedFinalizer.h
Source/JavaScriptCore/dfg/DFGFinalizer.h
Source/JavaScriptCore/dfg/DFGJITFinalizer.cpp
Source/JavaScriptCore/dfg/DFGJITFinalizer.h
Source/JavaScriptCore/dfg/DFGOSRExitPreparation.cpp
Source/JavaScriptCore/dfg/DFGOperations.cpp
Source/JavaScriptCore/dfg/DFGPlan.cpp
Source/JavaScriptCore/dfg/DFGPlan.h
Source/JavaScriptCore/dfg/DFGSpeculativeJIT32_64.cpp
Source/JavaScriptCore/dfg/DFGWorklist.cpp
Source/JavaScriptCore/ftl/FTLJITFinalizer.cpp
Source/JavaScriptCore/ftl/FTLJITFinalizer.h
Source/JavaScriptCore/heap/Heap.h
Source/JavaScriptCore/interpreter/Interpreter.cpp
Source/JavaScriptCore/jit/JITDriver.h [deleted file]
Source/JavaScriptCore/jit/JITStubs.cpp
Source/JavaScriptCore/jit/JITToDFGDeferredCompilationCallback.cpp [new file with mode: 0644]
Source/JavaScriptCore/jit/JITToDFGDeferredCompilationCallback.h [new file with mode: 0644]
Source/JavaScriptCore/llint/LLIntEntrypoints.cpp
Source/JavaScriptCore/llint/LLIntEntrypoints.h
Source/JavaScriptCore/llint/LLIntSlowPaths.cpp
Source/JavaScriptCore/runtime/ArrayPrototype.cpp
Source/JavaScriptCore/runtime/CommonSlowPaths.cpp
Source/JavaScriptCore/runtime/CompilationResult.cpp
Source/JavaScriptCore/runtime/CompilationResult.h
Source/JavaScriptCore/runtime/Executable.cpp
Source/JavaScriptCore/runtime/Executable.h
Source/JavaScriptCore/runtime/ExecutionHarness.h [deleted file]