Changeset 69045 in webkit for trunk/JavaScriptCore/jit/JITStubs.cpp

Timestamp:

Oct 4, 2010, 3:43:18 PM (15 years ago)

Author:

[email protected]

Message:

2010-10-04 Oliver Hunt <​[email protected]>

Reviewed by Geoff Garen.

Lazily create activation objects
​https://bugs.webkit.org/show_bug.cgi?id=47107

Make it possible to lazily create the activation object
for a function that needs one. This allows us to reduce
the overhead of entering a function that may require
an activation in some cases, but not always.

This does make exception handling a little more complex as
it's now necessary to verify that a callframes activation
has been created, and create it if not, in all of the
paths used in exception handling.

We also need to add logic to check for the existence of
the activation in the scoped_var opcodes, as well as
op_ret, op_ret_object_or_this and op_tearoff_activation
so that we can avoid creating an activation unnecesarily
on function exit.

• bytecode/CodeBlock.cpp: (JSC::CodeBlock::dump): (JSC::CodeBlock::reparseForExceptionInfoIfNecessary): (JSC::CodeBlock::createActivation):
• bytecode/CodeBlock.h: (JSC::CodeBlock::setActivationRegister): (JSC::CodeBlock::activationRegister):
• bytecode/Opcode.h:
• bytecompiler/BytecodeGenerator.cpp: (JSC::BytecodeGenerator::BytecodeGenerator): (JSC::BytecodeGenerator::emitNewFunctionInternal): (JSC::BytecodeGenerator::emitNewFunctionExpression): (JSC::BytecodeGenerator::createActivationIfNecessary):
• bytecompiler/BytecodeGenerator.h:
• interpreter/Interpreter.cpp: (JSC::Interpreter::resolveSkip): (JSC::Interpreter::resolveGlobalDynamic): (JSC::Interpreter::resolveBase): (JSC::Interpreter::unwindCallFrame): (JSC::Interpreter::throwException): (JSC::Interpreter::privateExecute):
• jit/JIT.cpp: (JSC::JIT::privateCompileMainPass):
• jit/JIT.h:
• jit/JITCall32_64.cpp: (JSC::JIT::emit_op_ret): (JSC::JIT::emit_op_ret_object_or_this):
• jit/JITOpcodes.cpp: (JSC::JIT::emit_op_end): (JSC::JIT::emit_op_get_scoped_var): (JSC::JIT::emit_op_put_scoped_var): (JSC::JIT::emit_op_tear_off_activation): (JSC::JIT::emit_op_ret): (JSC::JIT::emit_op_ret_object_or_this): (JSC::JIT::emit_op_create_activation): (JSC::JIT::emit_op_resolve_global_dynamic):
• jit/JITOpcodes32_64.cpp: (JSC::JIT::emit_op_get_scoped_var): (JSC::JIT::emit_op_put_scoped_var): (JSC::JIT::emit_op_tear_off_activation): (JSC::JIT::emit_op_create_activation):
• jit/JITStubs.cpp: (JSC::DEFINE_STUB_FUNCTION):

File:

• trunk/JavaScriptCore/jit/JITStubs.cpp (modified) (6 diffs)

trunk/JavaScriptCore/jit/JITStubs.cpp

@@ -1907 +1907 @@
 {
     STUB_INIT_STACK_FRAME(stackFrame);
-
+    
+    ASSERT(stackFrame.callFrame->codeBlock()->codeType() != FunctionCode || !stackFrame.callFrame->codeBlock()->needsFullScopeChain() || stackFrame.callFrame->r(stackFrame.callFrame->codeBlock()->activationRegister()).jsValue());
     return stackFrame.args[0].function()->make(stackFrame.callFrame, stackFrame.callFrame->scopeChain());
 }
@@ -2214 +2215 @@
 
     ASSERT(stackFrame.callFrame->codeBlock()->needsFullScopeChain());
+    JSValue activationValue = stackFrame.args[0].jsValue();
+    if (!activationValue) {
+        if (JSValue v = stackFrame.args[1].jsValue())
+            asArguments(v)->copyRegisters();
+        return;
+    }
     JSActivation* activation = asActivation(stackFrame.args[0].jsValue());
     activation->copyRegisters();
@@ -2686 +2693 @@
     ScopeChainIterator end = scopeChain->end();
     ASSERT(iter != end);
+    CodeBlock* codeBlock = callFrame->codeBlock();
+    bool checkTopLevel = codeBlock->codeType() == FunctionCode && codeBlock->needsFullScopeChain();
+    ASSERT(skip || !checkTopLevel);
+    if (checkTopLevel && skip--) {
+        if (callFrame->r(codeBlock->activationRegister()).jsValue())
+            ++iter;
+    }
     while (skip--) {
         ++iter;
@@ -2701 +2715 @@
     } while (++iter != end);
 
-    CodeBlock* codeBlock = callFrame->codeBlock();
     unsigned vPCIndex = codeBlock->bytecodeOffset(callFrame, STUB_RETURN_ADDRESS);
     stackFrame.globalData->exception = createUndefinedVariableError(callFrame, ident, vPCIndex, codeBlock);
@@ -3050 +3063 @@
     FunctionExecutable* function = stackFrame.args[0].function();
     JSFunction* func = function->make(callFrame, callFrame->scopeChain());
+    ASSERT(callFrame->codeBlock()->codeType() != FunctionCode || !callFrame->codeBlock()->needsFullScopeChain() || callFrame->r(callFrame->codeBlock()->activationRegister()).jsValue());
 
     /* 
@@ -3156 +3170 @@
 {
     STUB_INIT_STACK_FRAME(stackFrame);
+    ASSERT(stackFrame.callFrame->codeBlock()->codeType() != FunctionCode || !stackFrame.callFrame->codeBlock()->needsFullScopeChain() || stackFrame.callFrame->r(stackFrame.callFrame->codeBlock()->activationRegister()).jsValue());
 
     CallFrame* callFrame = stackFrame.callFrame;