op_to_this shouldn't use value profiling
https://bugs.webkit.org/show_bug.cgi?id=121920
Reviewed by Geoffrey Garen.
Source/JavaScriptCore:
Currently it's the only opcode that uses m_singletonValue, which is unnecessary. Our current plan is
to remove m_singletonValue so that GenGC can have a simpler story for handling CodeBlocks/FunctionExecutables
during nursery collections.
This patch adds an inline cache for the Structure of to_this so it no longer depends on the ValueProfile's
m_singletonValue. Since nobody uses m_singletonValue now, this patch also removes m_singletonValue from
ValueProfile.
* bytecode/CodeBlock.cpp:
(JSC::CodeBlock::CodeBlock):
(JSC::CodeBlock::finalizeUnconditionally):
(JSC::CodeBlock::stronglyVisitStrongReferences):
(JSC::CodeBlock::updateAllPredictionsAndCountLiveness):
(JSC::CodeBlock::updateAllValueProfilePredictions):
(JSC::CodeBlock::updateAllPredictions):
(JSC::CodeBlock::shouldOptimizeNow):
* bytecode/CodeBlock.h:
(JSC::CodeBlock::updateAllValueProfilePredictions):
(JSC::CodeBlock::updateAllPredictions):
* bytecode/LazyOperandValueProfile.cpp:
(JSC::CompressedLazyOperandValueProfileHolder::computeUpdatedPredictions):
* bytecode/LazyOperandValueProfile.h:
* bytecode/ValueProfile.h:
(JSC::ValueProfileBase::ValueProfileBase):
(JSC::ValueProfileBase::briefDescription):
(JSC::ValueProfileBase::dump):
(JSC::ValueProfileBase::computeUpdatedPrediction):
* bytecompiler/BytecodeGenerator.cpp:
(JSC::BytecodeGenerator::BytecodeGenerator):
* dfg/DFGByteCodeParser.cpp:
(JSC::DFG::ByteCodeParser::parseBlock):
* jit/JITOpcodes.cpp:
(JSC::JIT::emit_op_to_this):
(JSC::JIT::emitSlow_op_to_this):
* jit/JITOpcodes32_64.cpp:
(JSC::JIT::emit_op_to_this):
(JSC::JIT::emitSlow_op_to_this):
* llint/LowLevelInterpreter32_64.asm:
* llint/LowLevelInterpreter64.asm:
* runtime/CommonSlowPaths.cpp:
(JSC::SLOW_PATH_DECL):
LayoutTests:
Updated a couple tests that waited for two DFG compiles, but with this patch we
don't do two compiles any more, so we don't want to wait forever.
* js/script-tests/dfg-convert-this-polymorphic-object-then-exit-on-other.js:
* js/script-tests/dfg-convert-this-polymorphic-object-then-exit-on-string.js:
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@156468 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/bytecode/ValueProfile.h b/Source/JavaScriptCore/bytecode/ValueProfile.h
index 046b29b..0db9166 100644
--- a/Source/JavaScriptCore/bytecode/ValueProfile.h
+++ b/Source/JavaScriptCore/bytecode/ValueProfile.h
@@ -55,7 +55,6 @@
: m_bytecodeOffset(-1)
, m_prediction(SpecNone)
, m_numberOfSamplesInPrediction(0)
- , m_singletonValueIsTop(false)
{
for (unsigned i = 0; i < totalNumberOfBuckets; ++i)
m_buckets[i] = JSValue::encode(JSValue());
@@ -65,7 +64,6 @@
: m_bytecodeOffset(bytecodeOffset)
, m_prediction(SpecNone)
, m_numberOfSamplesInPrediction(0)
- , m_singletonValueIsTop(false)
{
for (unsigned i = 0; i < totalNumberOfBuckets; ++i)
m_buckets[i] = JSValue::encode(JSValue());
@@ -117,23 +115,13 @@
computeUpdatedPrediction(locker);
StringPrintStream out;
-
- if (m_singletonValueIsTop)
- out.print("predicting ", SpeculationDump(m_prediction));
- else if (m_singletonValue)
- out.print("predicting ", m_singletonValue);
-
+ out.print("predicting ", SpeculationDump(m_prediction));
return out.toCString();
}
void dump(PrintStream& out)
{
out.print("samples = ", totalNumberOfSamples(), " prediction = ", SpeculationDump(m_prediction));
- out.printf(", value = ");
- if (m_singletonValueIsTop)
- out.printf("TOP");
- else
- out.print(m_singletonValue);
bool first = true;
for (unsigned i = 0; i < totalNumberOfBuckets; ++i) {
JSValue value = JSValue::decode(m_buckets[i]);
@@ -150,7 +138,7 @@
// Updates the prediction and returns the new one. Never call this from any thread
// that isn't executing the code.
- SpeculatedType computeUpdatedPrediction(const ConcurrentJITLocker&, HeapOperation operation = NoOperation)
+ SpeculatedType computeUpdatedPrediction(const ConcurrentJITLocker&)
{
for (unsigned i = 0; i < totalNumberOfBuckets; ++i) {
JSValue value = JSValue::decode(m_buckets[i]);
@@ -160,23 +148,9 @@
m_numberOfSamplesInPrediction++;
mergeSpeculation(m_prediction, speculationFromValue(value));
- if (!m_singletonValueIsTop && !!value) {
- if (!m_singletonValue)
- m_singletonValue = value;
- else if (m_singletonValue != value)
- m_singletonValueIsTop = true;
- }
-
m_buckets[i] = JSValue::encode(JSValue());
}
- if (operation == Collection
- && !m_singletonValueIsTop
- && !!m_singletonValue
- && m_singletonValue.isCell()
- && !Heap::isMarked(m_singletonValue.asCell()))
- m_singletonValueIsTop = true;
-
return m_prediction;
}
@@ -185,9 +159,6 @@
SpeculatedType m_prediction;
unsigned m_numberOfSamplesInPrediction;
- bool m_singletonValueIsTop;
- JSValue m_singletonValue;
-
EncodedJSValue m_buckets[totalNumberOfBuckets];
};
