Refactored the DFG to make fewer assumptions about variable capture
https://bugs.webkit.org/show_bug.cgi?id=96680
Reviewed by Gavin Barraclough.
A variable capture optimization patch I'm working on broke DFG
correctness and the arguments simplification optimization phase, so I've
refactored both to make fewer assumptions about variable capture.
* bytecode/CodeBlock.h:
(JSC::CodeBlock::isCaptured): This is the new One True Way to find out
if a variable was captured. This gives us a single point of maintenance
as we chagne capture behavior.
* dfg/DFGAbstractState.cpp:
(JSC::DFG::AbstractState::clobberCapturedVars): Don't assume that captured
variables have any particular location. Instead, ask the One True Function.
* dfg/DFGArgumentsSimplificationPhase.cpp:
(JSC::DFG::ArgumentsSimplificationPhase::run):
(JSC::DFG::ArgumentsSimplificationPhase::observeProperArgumentsUse):
(JSC::DFG::ArgumentsSimplificationPhase::isOKToOptimize): Mechanical
changes to separate being captured from being 'arguments'. What used
to be
if (captured)
if (arguments)
x
y
is now
if (arguments)
x
y
else if (captured)
y
* dfg/DFGByteCodeParser.cpp:
(JSC::DFG::ByteCodeParser::getLocal):
(JSC::DFG::ByteCodeParser::setLocal):
(JSC::DFG::ByteCodeParser::getArgument):
(JSC::DFG::ByteCodeParser::setArgument):
(JSC::DFG::ByteCodeParser::flushDirect):
(JSC::DFG::ByteCodeParser::parseBlock):
(JSC::DFG::ByteCodeParser::InlineStackEntry::InlineStackEntry):
* dfg/DFGSpeculativeJIT.cpp:
(JSC::DFG::SpeculativeJIT::compile): Use the One True Function.
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@128544 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/dfg/DFGAbstractState.cpp b/Source/JavaScriptCore/dfg/DFGAbstractState.cpp
index f6145c1..b860a73 100644
--- a/Source/JavaScriptCore/dfg/DFGAbstractState.cpp
+++ b/Source/JavaScriptCore/dfg/DFGAbstractState.cpp
@@ -1522,11 +1522,14 @@
m_variables.local(i).makeTop();
}
} else {
- for (size_t i = m_codeBlock->m_numCapturedVars; i--;)
- m_variables.local(i).makeTop();
+ for (size_t i = m_codeBlock->m_numVars; i--;) {
+ if (m_codeBlock->isCaptured(i))
+ m_variables.local(i).makeTop();
+ }
}
- if (m_codeBlock->argumentsAreCaptured()) {
- for (size_t i = m_variables.numberOfArguments(); i--;)
+
+ for (size_t i = m_variables.numberOfArguments(); i--;) {
+ if (m_codeBlock->isCaptured(argumentToOperand(i)))
m_variables.argument(i).makeTop();
}
}
