Changeset 39697 in webkit for trunk/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp

Timestamp:

Jan 7, 2009, 5:46:14 PM (16 years ago)

Author:

[email protected]

Message:

2009-01-07 Sam Weinig <​[email protected]>

Reviewed by Geoffrey Garen.

<rdar://problem/6469060> Don't store exception information for a CodeBlock until first exception is thrown

Don't initially store exception information (lineNumber/expressionRange/getByIdExcecptionInfo)
in CodeBlocks blocks. Instead, re-parse for the data on demand and cache it then.

One important change that was needed to make this work was to pad op_get_global_var with nops to
be the same length as op_resolve_global, since one could be replaced for the other on re-parsing,
and we want to keep the offsets bytecode offsets the same.

1.3MB improvement on Membuster head.

• bytecode/CodeBlock.cpp: (JSC::CodeBlock::dump): Update op_get_global_var to account for the padding. (JSC::CodeBlock::dumpStatistics): Add more statistic dumping. (JSC::CodeBlock::CodeBlock): Initialize m_exceptionInfo. (JSC::CodeBlock::reparseForExceptionInfoIfNecessary): Re-parses the CodeBlocks associated SourceCode and steals the ExceptionInfo from it. (JSC::CodeBlock::lineNumberForBytecodeOffset): Creates the exception info on demand. (JSC::CodeBlock::expressionRangeForBytecodeOffset): Ditto. (JSC::CodeBlock::getByIdExceptionInfoForBytecodeOffset): Ditto.
• bytecode/CodeBlock.h: (JSC::CodeBlock::numberOfExceptionHandlers): Updated to account for m_exceptionInfo indirection. (JSC::CodeBlock::addExceptionHandler): Ditto. (JSC::CodeBlock::exceptionHandler): Ditto. (JSC::CodeBlock::clearExceptionInfo): Ditto. (JSC::CodeBlock::addExpressionInfo): Ditto. (JSC::CodeBlock::addGetByIdExceptionInfo): Ditto. (JSC::CodeBlock::numberOfLineInfos): Ditto. (JSC::CodeBlock::addLineInfo): Ditto. (JSC::CodeBlock::lastLineInfo): Ditto.

• bytecode/Opcode.h: Change length of op_get_global_var to match op_resolve_global.

• bytecode/SamplingTool.cpp: (JSC::SamplingTool::dump): Add comment indicating why it is okay not to pass a CallFrame.

• bytecompiler/BytecodeGenerator.cpp: (JSC::BytecodeGenerator::generate): Clear the exception info after generation for Function and Eval Code when not in regenerate for exception info mode. (JSC::BytecodeGenerator::BytecodeGenerator): Initialize m_regeneratingForExceptionInfo to false. (JSC::BytecodeGenerator::emitGetScopedVar): Pad op_get_global_var with 2 nops.
• bytecompiler/BytecodeGenerator.h: (JSC::BytecodeGenerator::setRegeneratingForExcpeptionInfo): Added.

• interpreter/Interpreter.cpp: (JSC::Interpreter::throwException): Pass the CallFrame to exception info accessors. (JSC::Interpreter::privateExecute): Ditto. (JSC::Interpreter::retrieveLastCaller): Ditto. (JSC::Interpreter::cti_op_new_error): Ditto.

• jit/JIT.cpp: (JSC::JIT::privateCompileMainPass): Pass the current bytecode offset instead of hard coding the line number, the stub will do the accessing if it gets called.

• parser/Nodes.cpp: (JSC::ProgramNode::emitBytecode): Moved. (JSC::ProgramNode::generateBytecode): Moved. (JSC::EvalNode::create): Moved. (JSC::EvalNode::bytecodeForExceptionInfoReparse): Added. (JSC::FunctionBodyNode::generateBytecode): Rename reparse to reparseInPlace. (JSC::FunctionBodyNode::bytecodeForExceptionInfoReparse): Addded.

• parser/Nodes.h: (JSC::ScopeNode::features): Added getter.
• parser/Parser.cpp: (JSC::Parser::reparseInPlace): Renamed from reparse.
• parser/Parser.h: (JSC::Parser::reparse): Added. Re-parses the passed in Node into a new Node.
• runtime/ExceptionHelpers.cpp: (JSC::createUndefinedVariableError): Pass along CallFrame. (JSC::createInvalidParamError): Ditto. (JSC::createNotAConstructorError): Ditto. (JSC::createNotAFunctionError): Ditto. (JSC::createNotAnObjectError): Ditto.

File:

• trunk/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp (modified) (6 diffs)

trunk/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp

@@ -1 +1 @@
 /*
- * Copyright (C) 2008 Apple Inc. All rights reserved.
+ * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Cameron Zwarich <[email protected]>
  *
@@ -152 +152 @@
 #endif
 
-    m_codeBlock->shrinkToFit();
     if ((m_codeType == FunctionCode && !m_codeBlock->needsFullScopeChain() && !m_codeBlock->usesArguments()) || m_codeType == EvalCode)
         symbolTable().clear();
+
+#if !ENABLE(OPCODE_SAMPLING)
+    if (!m_regeneratingForExceptionInfo && (m_codeType == FunctionCode || m_codeType == EvalCode))
+        m_codeBlock->clearExceptionInfo();
+#endif
+
+    m_codeBlock->shrinkToFit();
 }
 
@@ -206 +212 @@
     : m_shouldEmitDebugHooks(!!debugger)
     , m_shouldEmitProfileHooks(scopeChain.globalObject()->supportsProfiling())
+    , m_regeneratingForExceptionInfo(false)
     , m_scopeChain(&scopeChain)
     , m_symbolTable(symbolTable)
@@ -288 +295 @@
     : m_shouldEmitDebugHooks(!!debugger)
     , m_shouldEmitProfileHooks(scopeChain.globalObject()->supportsProfiling())
+    , m_regeneratingForExceptionInfo(false)
     , m_scopeChain(&scopeChain)
     , m_symbolTable(symbolTable)
@@ -359 +367 @@
     : m_shouldEmitDebugHooks(!!debugger)
     , m_shouldEmitProfileHooks(scopeChain.globalObject()->supportsProfiling())
+    , m_regeneratingForExceptionInfo(false)
     , m_scopeChain(&scopeChain)
     , m_symbolTable(symbolTable)
@@ -1015 +1024 @@
 {
     if (globalObject) {
+        // op_get_global_var must be the same length as op_resolve_global.
         emitOpcode(op_get_global_var);
         instructions().append(dst->index());
         instructions().append(asCell(globalObject));
         instructions().append(index);
+        instructions().append(0);
+        instructions().append(0);
         return dst;
     }