Changeset 162652 in webkit for trunk/Source/JavaScriptCore/bytecode/ExitKind.h

Timestamp:

Jan 23, 2014, 3:13:23 PM (11 years ago)

Author:

[email protected]

Message:

Enable DFG for the Debugger and Profiler.
<​https://webkit.org/b/122847>

Reviewed by Geoffrey Garen.

In this patch, we implement DFG op_debug as a series of 3 checks:

1. Check if the debugger pointer is non-null. This is needed in case the debugger has been detached but the DFG code is still running on the stack.
2. Check if Debugger::m_shouldPause is true.
3. Check if CodeBlock::m_numBreakpoints is non-zero.

These are the same 3 checks done in the LLINT and baselineJIT. But unlike
the LLINT and baselineJIT, these DFG checks are implemented as
speculationChecks. If the check fails, we OSR exit to the baselineJIT and
let it do the work of servicing the op_debug callback.

Stepping through code in the debugger would work the same way. The top
function being debugged has to be a LLINT or baselineJIT function because
we would have OSR exited if there is a breakpoint in that function. When
we step out of that function to its caller, we expect that the caller will
call back to the debugger at the next op_debug. If the caller function is
a DFG function, the op_debug site will fail its speculation check on
Debugger::m_shouldPause and deopt into a baselineJIT function. Execution
continues from there as usual, and the debugger gets its callback.

For the profile, op_profile_will_call and op_profile_did_call are
implemented as simple runtime calls to service the profiler.

With this patch, Octane performance with the WebInspector open jump from
~2000 to ~2500 (25% progression).

• bytecode/CodeBlock.h:

(JSC::CodeBlock::numBreakpointsAddress):

• bytecode/ExitKind.cpp:

(JSC::exitKindToString):

• bytecode/ExitKind.h:
• debugger/Debugger.cpp:

(JSC::Debugger::toggleBreakpoint):

• removed an obsolete assertion. The debugger can now handle DFG CodeBlocks too.
• debugger/Debugger.h:
• dfg/DFGAbstractInterpreterInlines.h:

(JSC::DFG::AbstractInterpreter<AbstractStateType>::executeEffects):

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::parseBlock):

• dfg/DFGCapabilities.cpp:

(JSC::DFG::capabilityLevel):

• dfg/DFGClobberize.h:

(JSC::DFG::clobberize):

• dfg/DFGFixupPhase.cpp:

(JSC::DFG::FixupPhase::fixupNode):

• dfg/DFGNodeType.h:
• dfg/DFGPredictionPropagationPhase.cpp:

(JSC::DFG::PredictionPropagationPhase::propagate):

• dfg/DFGSafeToExecute.h:

(JSC::DFG::safeToExecute):

• dfg/DFGSpeculativeJIT.h:

(JSC::DFG::SpeculativeJIT::callOperation):

• dfg/DFGSpeculativeJIT32_64.cpp:

(JSC::DFG::SpeculativeJIT::compile):

• dfg/DFGSpeculativeJIT64.cpp:

(JSC::DFG::SpeculativeJIT::compile):

• runtime/JSGlobalObject.h:

(JSC::JSGlobalObject::debuggerAddress):

File:

• trunk/Source/JavaScriptCore/bytecode/ExitKind.h (modified) (2 diffs)

trunk/Source/JavaScriptCore/bytecode/ExitKind.h

@@ -1 +1 @@
 /*
- * Copyright (C) 2012, 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2012, 2013, 2014 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -51 +51 @@
     UncountableInvalidation, // We exited because the code block was invalidated; this means that we've already counted the reasons why the code block was invalidated.
     UncountableWatchpoint, // We exited because of a watchpoint, which isn't counted because watchpoints do tracking themselves.
-    WatchdogTimerFired // We exited because we need to service the watchdog timer.
+    WatchdogTimerFired, // We exited because we need to service the watchdog timer.
+    DebuggerEvent // We exited because we need to service the debugger.
 };