Changeset 39697 in webkit for trunk/JavaScriptCore/bytecode/SamplingTool.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/bytecode/SamplingTool.cpp (modified) (2 diffs)

trunk/JavaScriptCore/bytecode/SamplingTool.cpp

@@ -1 +1 @@
 /*
- * Copyright (C) 2008 Apple Inc. All rights reserved.
+ * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -260 +260 @@
                     if (count) {
                         printf("    [% 4d] has sample count: % 4d\n", op, count);
-                        unsigned line = codeBlock->lineNumberForBytecodeOffset(op);
+                        // It is okay to pass 0 as the CallFrame for lineNumberForBytecodeOffset since
+                        // we ensure exception information when Sampling is enabled.
+                        unsigned line = codeBlock->lineNumberForBytecodeOffset(0, op);
                         lineCounts.set(line, (lineCounts.contains(line) ? lineCounts.get(line) : 0) + count);
                     }