Changeset 61430 in webkit for trunk/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp

Timestamp:

Jun 18, 2010, 1:14:23 PM (15 years ago)

Author:

[email protected]

Message:

2010-06-17 Oliver Hunt <​[email protected]>

Reviewed by Sam Weinig.

Don't throw away exception information for functions that use exceptions
​https://bugs.webkit.org/show_bug.cgi?id=40786

Simple patch to stop JSC from throwing away the exception information
of a function that uses "exceptiony" features like try and throw. This
is a speed up for catching expressions but it's difficult to quantify as
the old cost of reparsing is amortised over all exceptions caught in the
effected function.

• bytecode/CodeBlock.cpp: (JSC::CodeBlock::reparseForExceptionInfoIfNecessary):
• bytecompiler/BytecodeGenerator.cpp: (JSC::BytecodeGenerator::generate): (JSC::BytecodeGenerator::emitCatch):
• bytecompiler/BytecodeGenerator.h: (JSC::BytecodeGenerator::emitThrow):

File:

• trunk/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp (modified) (5 diffs)

trunk/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp

@@ -157 +157 @@
 
 #if !ENABLE(OPCODE_SAMPLING)
-    if (!m_regeneratingForExceptionInfo && (m_codeType == FunctionCode || m_codeType == EvalCode))
+    if (!m_regeneratingForExceptionInfo && !m_usesExceptions && (m_codeType == FunctionCode || m_codeType == EvalCode))
         m_codeBlock->clearExceptionInfo();
 #endif
@@ -220 +220 @@
     , m_lastOpcodeID(op_end)
     , m_emitNodeDepth(0)
+    , m_usesExceptions(false)
     , m_regeneratingForExceptionInfo(false)
     , m_codeBlockBeingRegeneratedFrom(0)
@@ -305 +306 @@
     , m_lastOpcodeID(op_end)
     , m_emitNodeDepth(0)
+    , m_usesExceptions(false)
     , m_regeneratingForExceptionInfo(false)
     , m_codeBlockBeingRegeneratedFrom(0)
@@ -406 +408 @@
     , m_lastOpcodeID(op_end)
     , m_emitNodeDepth(0)
+    , m_usesExceptions(false)
     , m_regeneratingForExceptionInfo(false)
     , m_codeBlockBeingRegeneratedFrom(0)
@@ -1843 +1846 @@
 RegisterID* BytecodeGenerator::emitCatch(RegisterID* targetRegister, Label* start, Label* end)
 {
+    m_usesExceptions = true;
 #if ENABLE(JIT)
     HandlerInfo info = { start->bind(0, 0), end->bind(0, 0), instructions().size(), m_dynamicScopeDepth + m_baseScopeDepth, CodeLocationLabel() };