Changeset 252032 in webkit for trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp

Timestamp:

Nov 4, 2019, 6:52:02 PM (6 years ago)

Author:

[email protected]

Message:

[JSC] Introduce LinkTimeConstant mechanism
​https://bugs.webkit.org/show_bug.cgi?id=153792

Reviewed by Saam Barati.

Source/JavaScriptCore:

We are using private-name-variables of JSGlobalObject as a way to access to constants that are materialized per JSGlobalObject.
And we also have special-pointers and old link-time-constants to access to per JSGlobalObject constants.
We have bytecode intrinsic constants, but it is only available for per VM values.

However, these ones have multiple problems.

1. private-name-variables is too costly. We need to have an entry in JSGlobalObject's variable, this makes SymbolTable of JSGlobalObject large. It also requires WatchpointSet to make it constant-fold in DFG. And accessing these variables from builtin JS takes op_resolve_scope and op_get_from_scope, enlarging bytecode and slow in interpreter and baseline compared to just getting them as a constant register.
2. special-pointers are tailored to op_jne_ptr opcode, and not usable in the other bytecode since this is completely separate from VirtualRegister.
3. Old link-time-constants implementation is putting array of all link-time-constants on each UnlinkedCodeBlock, even if it is not used. If you increase # of link-time-constant, it increases sizeof(UnlinkedCodeBlock).

In this patch, we introduce a new link-time-constant mechanism and remove the above old ones mostly. (private-name-variables still exists for WebCore and @assert).
We manage link-time-constants in BytecodeIntrinsicRegistry, and emit Int32:LinkTimeConstantID constant when generating an UnlinkedCodeBlock. Later, this constant
is alternated to an actual value when we link UnlinkedCodeBlock to CodeBlock with specific JSGlobalObject. private-name-variables accesses are now converted to
constant register so that it is very efficiently accessed and it reduces memory used for SymbolTable and WatchpointSet. op_jne_ptr takes link-time-constant
VirtualRegisters instead of special-pointers, so that we can remove special-pointers mechanism. We also replace old link-time-constants with new one, which reduces
sizeof(UnlinkedCodeBlock).

Furthermore, new link-time-constant supports lazy initialization by using LazyProperty in JSGlobalObject. This allows us to lazily generate many internal functions
that are previously initialized eagerly. This reduces # of allocated JSFunction significantly when initializing JSGlobalObject.

This patch also manually adds 256 to MarkedSpace's size-class. We empirically know that adding 256 here makes sequence of size-class better for memory consumption.
But this was achieved by adding sizeof(UnlinkedFunctionCodeBlock). Now sizeof(UnlinkedFunctionCodeBlock) is changed by this patch, and this patch unintentionally
breaks that sequence. We should explicitly add 256 instead of adding sizeof(UnlinkedFunctionCodeBlock) adhocly.

• CMakeLists.txt:
• JavaScriptCore.xcodeproj/project.pbxproj:
• Scripts/wkbuiltins/builtins_generate_combined_header.py:

(generate_section_for_global_private_code_name_macro):

• Sources.txt:
• builtins/BuiltinNames.h:
• builtins/PromiseConstructor.js:

(nakedConstructor.Promise):
(nakedConstructor.InternalPromise):
(nakedConstructor.Promise.reject): Deleted.
(nakedConstructor.InternalPromise.reject): Deleted.

• bytecode/BytecodeDumper.cpp:

(JSC::CodeBlockBytecodeDumper<Block>::dumpConstants):

• bytecode/BytecodeIntrinsicRegistry.cpp:

(JSC::BytecodeIntrinsicRegistry::BytecodeIntrinsicRegistry):
(JSC::BytecodeIntrinsicRegistry::lookup const):

• bytecode/BytecodeIntrinsicRegistry.h:

(JSC::BytecodeIntrinsicRegistry::Entry::Entry):
(JSC::BytecodeIntrinsicRegistry::Entry::type const):
(JSC::BytecodeIntrinsicRegistry::Entry::linkTimeConstant const):
(JSC::BytecodeIntrinsicRegistry::Entry::emitter const):

• bytecode/BytecodeList.rb:
• bytecode/CodeBlock.cpp:

(JSC::CodeBlock::finishCreation):
(JSC::CodeBlock::setConstantRegisters):

• bytecode/Fits.h:
• bytecode/LinkTimeConstant.cpp: Renamed from Source/JavaScriptCore/bytecode/SpecialPointer.h.

(WTF::printInternal):

• bytecode/LinkTimeConstant.h: Added.
• bytecode/SpecialPointer.cpp: Removed.
• bytecode/UnlinkedCodeBlock.cpp:

(JSC::UnlinkedCodeBlock::UnlinkedCodeBlock):

• bytecode/UnlinkedCodeBlock.h:

(JSC::UnlinkedCodeBlock::addConstant):
(JSC::UnlinkedCodeBlock::registerIndexForLinkTimeConstant): Deleted.

• bytecompiler/BytecodeGenerator.cpp:

(JSC::BytecodeGenerator::BytecodeGenerator):
(JSC::BytecodeGenerator::emitJumpIfNotFunctionCall):
(JSC::BytecodeGenerator::emitJumpIfNotFunctionApply):
(JSC::BytecodeGenerator::emitExpectedFunctionSnippet):
(JSC::BytecodeGenerator::emitCallDefineProperty):
(JSC::BytecodeGenerator::emitGetAsyncIterator):

• bytecompiler/BytecodeGenerator.h:
• bytecompiler/NodesCodegen.cpp:

(JSC::ImportNode::emitBytecode):
(JSC::BytecodeIntrinsicNode::emitBytecode):
(JSC::promiseInternalFieldIndex):
(JSC::generatorInternalFieldIndex):
(JSC::asyncGeneratorInternalFieldIndex):
(JSC::FunctionNode::emitBytecode):
(JSC::ObjectPatternNode::bindValue const):
(JSC::ObjectSpreadExpressionNode::emitBytecode):

• dfg/DFGByteCodeParser.cpp:

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

• heap/MarkedSpace.cpp:
• jit/JITOpcodes.cpp:

(JSC::JIT::emit_op_jneq_ptr):

• jit/JITOpcodes32_64.cpp:

(JSC::JIT::emit_op_jneq_ptr):

• llint/LowLevelInterpreter32_64.asm:
• llint/LowLevelInterpreter64.asm:
• parser/ASTBuilder.h:

(JSC::ASTBuilder::createResolve):
(JSC::ASTBuilder::makeFunctionCallNode):

• parser/NodeConstructors.h:

(JSC::BytecodeIntrinsicNode::BytecodeIntrinsicNode):

• parser/Nodes.h:
• runtime/CachedTypes.cpp:

(JSC::CachedCodeBlock<CodeBlockType>::decode const):
(JSC::CachedCodeBlock<CodeBlockType>::encode):

• runtime/JSCJSValue.h:
• runtime/JSGlobalObject.cpp:

(JSC::JSGlobalObject::JSGlobalObject):
(JSC::JSGlobalObject::init):
(JSC::JSGlobalObject::visitChildren):

• runtime/JSGlobalObject.h:

(JSC::JSGlobalObject::linkTimeConstant const):
(JSC::JSGlobalObject::callFunction const): Deleted.
(JSC::JSGlobalObject::applyFunction const): Deleted.
(JSC::JSGlobalObject::throwTypeErrorFunction const): Deleted.
(JSC::JSGlobalObject::newPromiseCapabilityFunction const): Deleted.
(JSC::JSGlobalObject::resolvePromiseFunction const): Deleted.
(JSC::JSGlobalObject::rejectPromiseFunction const): Deleted.
(JSC::JSGlobalObject::promiseProtoThenFunction const): Deleted.
(JSC::JSGlobalObject::regExpProtoExecFunction const): Deleted.
(JSC::JSGlobalObject::regExpProtoGlobalGetter const): Deleted.
(JSC::JSGlobalObject::regExpProtoUnicodeGetter const): Deleted.
(JSC::JSGlobalObject::actualPointerFor): Deleted.
(JSC::JSGlobalObject::jsCellForLinkTimeConstant): Deleted.

• runtime/JSGlobalObjectInlines.h:

(JSC::JSGlobalObject::throwTypeErrorFunction const):
(JSC::JSGlobalObject::newPromiseCapabilityFunction const):
(JSC::JSGlobalObject::resolvePromiseFunction const):
(JSC::JSGlobalObject::rejectPromiseFunction const):
(JSC::JSGlobalObject::promiseProtoThenFunction const):
(JSC::JSGlobalObject::regExpProtoExecFunction const):
(JSC::JSGlobalObject::regExpProtoGlobalGetter const):
(JSC::JSGlobalObject::regExpProtoUnicodeGetter const):

LayoutTests:

• inspector/debugger/tail-deleted-frames/tail-deleted-frames-this-value-expected.txt:

File:

• trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/bytecode/CodeBlock.cpp

@@ -400 +400 @@
     RETURN_IF_EXCEPTION(throwScope, false);
 
-    for (unsigned i = 0; i < LinkTimeConstantCount; i++) {
-        LinkTimeConstant type = static_cast<LinkTimeConstant>(i);
-        if (unsigned registerIndex = unlinkedCodeBlock->registerIndexForLinkTimeConstant(type))
-            m_constantRegisters[registerIndex].set(vm, this, m_globalObject->jsCellForLinkTimeConstant(type));
-    }
-
     // We already have the cloned symbol table for the module environment since we need to instantiate
     // the module environments before linking the code block. We replace the stored symbol table with the already cloned one.
@@ -906 +900 @@
     for (size_t i = 0; i < count; i++) {
         JSValue constant = constants[i].get();
-
-        if (!constant.isEmpty()) {
-            if (constant.isCell()) {
-                JSCell* cell = constant.asCell();
-                if (SymbolTable* symbolTable = jsDynamicCast<SymbolTable*>(vm, cell)) {
-                    if (m_unlinkedCode->wasCompiledWithTypeProfilerOpcodes()) {
-                        ConcurrentJSLocker locker(symbolTable->m_lock);
-                        symbolTable->prepareForTypeProfiling(locker);
+        switch (constantsSourceCodeRepresentation[i]) {
+        case SourceCodeRepresentation::LinkTimeConstant:
+            constant = globalObject->linkTimeConstant(static_cast<LinkTimeConstant>(constant.asInt32AsAnyInt()));
+            break;
+        case SourceCodeRepresentation::Other:
+        case SourceCodeRepresentation::Integer:
+        case SourceCodeRepresentation::Double:
+            if (!constant.isEmpty()) {
+                if (constant.isCell()) {
+                    JSCell* cell = constant.asCell();
+                    if (SymbolTable* symbolTable = jsDynamicCast<SymbolTable*>(vm, cell)) {
+                        if (m_unlinkedCode->wasCompiledWithTypeProfilerOpcodes()) {
+                            ConcurrentJSLocker locker(symbolTable->m_lock);
+                            symbolTable->prepareForTypeProfiling(locker);
+                        }
+
+                        SymbolTable* clone = symbolTable->cloneScopePart(vm);
+                        if (wasCompiledWithDebuggingOpcodes())
+                            clone->setRareDataCodeBlock(this);
+
+                        constant = clone;
+                    } else if (auto* descriptor = jsDynamicCast<JSTemplateObjectDescriptor*>(vm, cell)) {
+                        auto* templateObject = topLevelExecutable->createTemplateObject(globalObject, descriptor);
+                        RETURN_IF_EXCEPTION(scope, void());
+                        constant = templateObject;
                     }
-
-                    SymbolTable* clone = symbolTable->cloneScopePart(vm);
-                    if (wasCompiledWithDebuggingOpcodes())
-                        clone->setRareDataCodeBlock(this);
-
-                    constant = clone;
-                } else if (auto* descriptor = jsDynamicCast<JSTemplateObjectDescriptor*>(vm, cell)) {
-                    auto* templateObject = topLevelExecutable->createTemplateObject(globalObject, descriptor);
-                    RETURN_IF_EXCEPTION(scope, void());
-                    constant = templateObject;
                 }
             }
-        }
-
+            break;
+        }
         m_constantRegisters[i].set(vm, this, constant);
     }