Changeset 39720 in webkit for trunk/JavaScriptCore/jit

Timestamp:

Jan 8, 2009, 2:51:19 PM (16 years ago)

Author:

[email protected]

Message:

2009-01-08 Sam Weinig <​[email protected]>

Reviewed by Oliver Hunt.

Fix for ​https://bugs.webkit.org/show_bug.cgi?id=23197
Delay creating the PCVector until an exception is thrown
Part of <rdar://problem/6469060>
Don't store exception information for a CodeBlock until first exception is thrown

• Change the process for re-parsing/re-generating bytecode for exception information to use data from the original CodeBlock (offsets of GlobalResolve instructions) to aid in creating an identical instruction stream on re-parse, instead of padding interchangeable opcodes, which would result in different JITed code.
• Fix bug where the wrong ScopeChainNode was used when re-parsing/regenerating from within some odd modified scope chains.
• Lazily create the pcVector by re-JITing the regenerated CodeBlock and stealing the the pcVector from it.

Saves ~2MB on Membuster head.

• bytecode/CodeBlock.cpp: (JSC::CodeBlock::dump): (JSC::CodeBlock::reparseForExceptionInfoIfNecessary): (JSC::CodeBlock::hasGlobalResolveInstructionAtBytecodeOffset): (JSC::CodeBlock::hasGlobalResolveInfoAtBytecodeOffset):
• bytecode/CodeBlock.h: (JSC::JITCodeRef::JITCodeRef): (JSC::GlobalResolveInfo::GlobalResolveInfo): (JSC::CodeBlock::getBytecodeIndex): (JSC::CodeBlock::addGlobalResolveInstruction): (JSC::CodeBlock::addGlobalResolveInfo): (JSC::CodeBlock::addFunctionRegisterInfo): (JSC::CodeBlock::hasExceptionInfo): (JSC::CodeBlock::pcVector): (JSC::EvalCodeBlock::EvalCodeBlock): (JSC::EvalCodeBlock::baseScopeDepth):
• bytecode/Opcode.h:
• bytecompiler/BytecodeGenerator.cpp: (JSC::BytecodeGenerator::BytecodeGenerator): (JSC::BytecodeGenerator::emitResolve): (JSC::BytecodeGenerator::emitGetScopedVar):
• bytecompiler/BytecodeGenerator.h: (JSC::BytecodeGenerator::setRegeneratingForExceptionInfo):
• interpreter/Interpreter.cpp: (JSC::bytecodeOffsetForPC): (JSC::Interpreter::unwindCallFrame): (JSC::Interpreter::privateExecute): (JSC::Interpreter::retrieveLastCaller): (JSC::Interpreter::cti_op_instanceof): (JSC::Interpreter::cti_op_call_NotJSFunction): (JSC::Interpreter::cti_op_resolve): (JSC::Interpreter::cti_op_construct_NotJSConstruct): (JSC::Interpreter::cti_op_resolve_func): (JSC::Interpreter::cti_op_resolve_skip): (JSC::Interpreter::cti_op_resolve_global): (JSC::Interpreter::cti_op_resolve_with_base): (JSC::Interpreter::cti_op_throw): (JSC::Interpreter::cti_op_in): (JSC::Interpreter::cti_vm_throw):
• jit/JIT.cpp: (JSC::JIT::privateCompile):
• parser/Nodes.cpp: (JSC::EvalNode::generateBytecode): (JSC::EvalNode::bytecodeForExceptionInfoReparse): (JSC::FunctionBodyNode::bytecodeForExceptionInfoReparse):
• parser/Nodes.h:

File:

• trunk/JavaScriptCore/jit/JIT.cpp (modified) (2 diffs)

trunk/JavaScriptCore/jit/JIT.cpp

@@ -1599 +1599 @@
     void* code = m_assembler.executableCopy(allocator.get());
     JITCodeRef codeRef(code, allocator);
- 
+#ifndef NDEBUG
+    codeRef.codeSize = m_assembler.size();
+#endif
+
     PatchBuffer patchBuffer(code);
 
@@ -1635 +1638 @@
     }
 
-    m_codeBlock->pcVector().reserveCapacity(m_calls.size());
     for (Vector<CallRecord>::iterator iter = m_calls.begin(); iter != m_calls.end(); ++iter) {
         if (iter->to)
             patchBuffer.link(iter->from, iter->to);
-        m_codeBlock->pcVector().append(PC(reinterpret_cast<void**>(patchBuffer.addressOf(iter->from)) - reinterpret_cast<void**>(code), iter->bytecodeIndex));
+    }
+
+    if (m_codeBlock->hasExceptionInfo()) {
+        m_codeBlock->pcVector().reserveCapacity(m_calls.size());
+        for (Vector<CallRecord>::iterator iter = m_calls.begin(); iter != m_calls.end(); ++iter)
+            m_codeBlock->pcVector().append(PC(reinterpret_cast<void**>(patchBuffer.addressOf(iter->from)) - reinterpret_cast<void**>(code), iter->bytecodeIndex));
     }