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-rw-r--r--JavaScriptCore/bytecompiler/BytecodeGenerator.cpp88
1 files changed, 55 insertions, 33 deletions
diff --git a/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp b/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
index e5f3d15..cdf87d2 100644
--- a/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
+++ b/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
@@ -174,8 +174,7 @@ bool BytecodeGenerator::addVar(const Identifier& ident, bool isConstant, Registe
return false;
}
- ++m_codeBlock->m_numVars;
- r0 = newRegister();
+ r0 = addVar();
return true;
}
@@ -295,6 +294,7 @@ BytecodeGenerator::BytecodeGenerator(FunctionBodyNode* functionBody, const Debug
, m_symbolTable(symbolTable)
, m_scopeNode(functionBody)
, m_codeBlock(codeBlock)
+ , m_activationRegister(0)
, m_finallyDepth(0)
, m_dynamicScopeDepth(0)
, m_baseScopeDepth(0)
@@ -312,29 +312,35 @@ BytecodeGenerator::BytecodeGenerator(FunctionBodyNode* functionBody, const Debug
codeBlock->setGlobalData(m_globalData);
- bool usesArguments = functionBody->usesArguments();
- codeBlock->setUsesArguments(usesArguments);
- if (usesArguments) {
- m_argumentsRegister.setIndex(RegisterFile::OptionalCalleeArguments);
- addVar(propertyNames().arguments, false);
- }
-
if (m_codeBlock->needsFullScopeChain()) {
- ++m_codeBlock->m_numVars;
- m_activationRegisterIndex = newRegister()->index();
+ m_activationRegister = addVar();
emitOpcode(op_enter_with_activation);
- instructions().append(m_activationRegisterIndex);
+ instructions().append(m_activationRegister->index());
} else
emitOpcode(op_enter);
- if (usesArguments) {
+ // Both op_tear_off_activation and op_tear_off_arguments tear off the 'arguments'
+ // object, if created.
+ if (m_codeBlock->needsFullScopeChain() || functionBody->usesArguments()) {
+ RegisterID* unmodifiedArgumentsRegister = addVar(); // Anonymous, so it can't be modified by user code.
+ RegisterID* argumentsRegister = addVar(propertyNames().arguments, false); // Can be changed by assigning to 'arguments'.
+
+ // We can save a little space by hard-coding the knowledge that the two
+ // 'arguments' values are stored in consecutive registers, and storing
+ // only the index of the assignable one.
+ codeBlock->setArgumentsRegister(argumentsRegister->index());
+ ASSERT_UNUSED(unmodifiedArgumentsRegister, unmodifiedArgumentsRegister->index() == JSC::unmodifiedArgumentsRegister(codeBlock->argumentsRegister()));
+
emitOpcode(op_init_arguments);
+ instructions().append(argumentsRegister->index());
// The debugger currently retrieves the arguments object from an activation rather than pulling
// it from a call frame. In the long-term it should stop doing that (<rdar://problem/6911886>),
// but for now we force eager creation of the arguments object when debugging.
- if (m_shouldEmitDebugHooks)
+ if (m_shouldEmitDebugHooks) {
emitOpcode(op_create_arguments);
+ instructions().append(argumentsRegister->index());
+ }
}
const DeclarationStacks::FunctionStack& functionStack = functionBody->functionStack();
@@ -359,7 +365,7 @@ BytecodeGenerator::BytecodeGenerator(FunctionBodyNode* functionBody, const Debug
++m_nextParameterIndex;
++m_codeBlock->m_numParameters;
- if (functionBody->usesThis() || m_shouldEmitDebugHooks) {
+ if (!isConstructor() && (functionBody->usesThis() || m_shouldEmitDebugHooks)) {
emitOpcode(op_convert_this);
instructions().append(m_thisRegister.index());
}
@@ -1025,7 +1031,7 @@ bool BytecodeGenerator::findScopedProperty(const Identifier& property, int& inde
globalObject = currentVariableObject;
return false;
}
- stackDepth = depth;
+ stackDepth = depth + m_codeBlock->needsFullScopeChain();
index = entry.getIndex();
if (++iter == end)
globalObject = currentVariableObject;
@@ -1037,7 +1043,7 @@ bool BytecodeGenerator::findScopedProperty(const Identifier& property, int& inde
requiresDynamicChecks |= scopeRequiresDynamicChecks;
}
// Can't locate the property but we're able to avoid a few lookups.
- stackDepth = depth;
+ stackDepth = depth + m_codeBlock->needsFullScopeChain();
index = missingSymbolMarker();
JSObject* scope = *iter;
if (++iter == end)
@@ -1385,7 +1391,6 @@ RegisterID* BytecodeGenerator::emitNewRegExp(RegisterID* dst, RegExp* regExp)
return dst;
}
-
RegisterID* BytecodeGenerator::emitNewFunctionExpression(RegisterID* r0, FuncExprNode* n)
{
FunctionBodyNode* function = n->body();
@@ -1404,13 +1409,16 @@ RegisterID* BytecodeGenerator::emitCall(RegisterID* dst, RegisterID* func, Regis
void BytecodeGenerator::createArgumentsIfNecessary()
{
- if (m_codeBlock->usesArguments() && m_codeType == FunctionCode)
- emitOpcode(op_create_arguments);
+ if (m_codeType != FunctionCode)
+ return;
+ ASSERT(m_codeBlock->usesArguments());
+
+ emitOpcode(op_create_arguments);
+ instructions().append(m_codeBlock->argumentsRegister());
}
RegisterID* BytecodeGenerator::emitCallEval(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode* argumentsNode, unsigned divot, unsigned startOffset, unsigned endOffset)
{
- createArgumentsIfNecessary();
return emitCall(op_call_eval, dst, func, thisRegister, argumentsNode, divot, startOffset, endOffset);
}
@@ -1466,10 +1474,13 @@ RegisterID* BytecodeGenerator::emitCall(OpcodeID opcodeID, RegisterID* dst, Regi
// Emit call.
emitOpcode(opcodeID);
- instructions().append(dst->index()); // dst
instructions().append(func->index()); // func
instructions().append(argv.size()); // argCount
instructions().append(argv[0]->index() + argv.size() + RegisterFile::CallFrameHeaderSize); // registerOffset
+ if (dst != ignoredResult()) {
+ emitOpcode(op_call_put_result);
+ instructions().append(dst->index()); // dst
+ }
if (m_shouldEmitProfileHooks) {
emitOpcode(op_profile_did_call);
@@ -1511,10 +1522,13 @@ RegisterID* BytecodeGenerator::emitCallVarargs(RegisterID* dst, RegisterID* func
// Emit call.
emitOpcode(op_call_varargs);
- instructions().append(dst->index()); // dst
instructions().append(func->index()); // func
instructions().append(argCountRegister->index()); // arg count
instructions().append(thisRegister->index() + RegisterFile::CallFrameHeaderSize); // initial registerOffset
+ if (dst != ignoredResult()) {
+ emitOpcode(op_call_put_result);
+ instructions().append(dst->index()); // dst
+ }
if (m_shouldEmitProfileHooks) {
emitOpcode(op_profile_did_call);
instructions().append(func->index());
@@ -1526,10 +1540,22 @@ RegisterID* BytecodeGenerator::emitReturn(RegisterID* src)
{
if (m_codeBlock->needsFullScopeChain()) {
emitOpcode(op_tear_off_activation);
- instructions().append(m_activationRegisterIndex);
- } else if (m_codeBlock->usesArguments() && m_codeBlock->m_numParameters > 1)
+ instructions().append(m_activationRegister->index());
+ instructions().append(m_codeBlock->argumentsRegister());
+ } else if (m_codeBlock->usesArguments() && m_codeBlock->m_numParameters > 1) { // If there are no named parameters, there's nothing to tear off, since extra / unnamed parameters get copied to the arguments object at construct time.
emitOpcode(op_tear_off_arguments);
+ instructions().append(m_codeBlock->argumentsRegister());
+ }
+ // Constructors use op_ret_object_or_this to check the result is an
+ // object, unless we can trivially determine the check is not
+ // necessary (currently, if the return value is 'this').
+ if (isConstructor() && (src->index() != m_thisRegister.index())) {
+ emitOpcode(op_ret_object_or_this);
+ instructions().append(src->index());
+ instructions().append(m_thisRegister.index());
+ return src;
+ }
return emitUnaryNoDstOp(op_ret, src);
}
@@ -1589,16 +1615,15 @@ RegisterID* BytecodeGenerator::emitConstruct(RegisterID* dst, RegisterID* func,
#endif
emitOpcode(op_construct);
- instructions().append(dst->index()); // dst
instructions().append(func->index()); // func
instructions().append(argv.size()); // argCount
instructions().append(argv[0]->index() + argv.size() + RegisterFile::CallFrameHeaderSize); // registerOffset
instructions().append(funcProto->index()); // proto
instructions().append(argv[0]->index()); // thisRegister
-
- emitOpcode(op_construct_verify);
- instructions().append(dst->index());
- instructions().append(argv[0]->index());
+ if (dst != ignoredResult()) {
+ emitOpcode(op_call_put_result);
+ instructions().append(dst->index()); // dst
+ }
if (m_shouldEmitProfileHooks) {
emitOpcode(op_profile_did_call);
@@ -1635,7 +1660,6 @@ RegisterID* BytecodeGenerator::emitPushScope(RegisterID* scope)
context.isFinallyBlock = false;
m_scopeContextStack.append(context);
m_dynamicScopeDepth++;
- createArgumentsIfNecessary();
return emitUnaryNoDstOp(op_push_scope, scope);
}
@@ -1899,8 +1923,6 @@ void BytecodeGenerator::emitPushNewScope(RegisterID* dst, const Identifier& prop
context.isFinallyBlock = false;
m_scopeContextStack.append(context);
m_dynamicScopeDepth++;
-
- createArgumentsIfNecessary();
emitOpcode(op_push_new_scope);
instructions().append(dst->index());
generated by cgit v1.1 at 2024-06-01 15:04:40 +0000