AuroraMiddleware/v8
1
0
Fork 0
Code Issues 2 Pull Requests Releases Wiki Activity

Eagerly set arguments_, new_target_ and ths_function_ Scope, and unset if we don't need to allocate them.

Browse Source 
This probably slightly speeds up AllocateParameterLocals, but more importantly it removes ast_value_factory_ uses. If we get rid of ast_value_factory from Scope it's easier to lazily allocate it later from within a ScopeState object.

BUG=v8:5209

Review-Url: https://codereview.chromium.org/2158333002
Cr-Commit-Position: refs/heads/master@{#37868}
This commit is contained in:
verwaest 2016-07-19 06:00:39 -07:00 committed by Commit bot
parent 562bb5823c
commit 3442519d56
1 changed files with 30 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

60
src/ast/scopes.cc
View File

@ -320,16 +320,19 @@ void Scope::Initialize() {
// Declare 'arguments' variable which exists in all non arrow functions.
// Note that it might never be accessed, in which case it won't be
// allocated during variable allocation.
variables_.Declare(this, ast_value_factory_->arguments_string(), VAR,
Variable::ARGUMENTS, kCreatedInitialized);
arguments_ =
variables_.Declare(this, ast_value_factory_->arguments_string(), VAR,
Variable::ARGUMENTS, kCreatedInitialized);
variables_.Declare(this, ast_value_factory_->new_target_string(), CONST,
Variable::NORMAL, kCreatedInitialized);
new_target_ =
variables_.Declare(this, ast_value_factory_->new_target_string(), CONST,
Variable::NORMAL, kCreatedInitialized);
if (IsConciseMethod(function_kind_) || IsClassConstructor(function_kind_) ||
IsAccessorFunction(function_kind_)) {
variables_.Declare(this, ast_value_factory_->this_function_string(),
CONST, Variable::NORMAL, kCreatedInitialized);
this_function_ =
variables_.Declare(this, ast_value_factory_->this_function_string(),
CONST, Variable::NORMAL, kCreatedInitialized);
}
}
}
@ -1332,14 +1335,11 @@ void Scope::AllocateHeapSlot(Variable* var) {
void Scope::AllocateParameterLocals(Isolate* isolate) {
DCHECK(is_function_scope());
Variable* arguments = LookupLocal(ast_value_factory_->arguments_string());
// Functions have 'arguments' declared implicitly in all non arrow functions.
DCHECK(arguments != nullptr || is_arrow_scope());
bool uses_sloppy_arguments = false;
if (arguments != nullptr && MustAllocate(arguments) &&
!HasArgumentsParameter(isolate)) {
// Functions have 'arguments' declared implicitly in all non arrow functions.
if (arguments_ != nullptr) {
// 'arguments' is used. Unless there is also a parameter called
// 'arguments', we must be conservative and allocate all parameters to
// the context assuming they will be captured by the arguments object.
@ -1348,21 +1348,25 @@ void Scope::AllocateParameterLocals(Isolate* isolate) {
// that specific parameter value and cannot be used to access the
// parameters, which is why we don't need to allocate an arguments
// object in that case.
if (MustAllocate(arguments_) && !HasArgumentsParameter(isolate)) {
// In strict mode 'arguments' does not alias formal parameters.
// Therefore in strict mode we allocate parameters as if 'arguments'
// were not used.
// If the parameter list is not simple, arguments isn't sloppy either.
uses_sloppy_arguments =
is_sloppy(language_mode()) && has_simple_parameters();
} else {
// 'arguments' is unused. Tell the code generator that it does not need to
// allocate the arguments object by nulling out arguments_.
arguments_ = nullptr;
}
// We are using 'arguments'. Tell the code generator that is needs to
// allocate the arguments object by setting 'arguments_'.
arguments_ = arguments;
// In strict mode 'arguments' does not alias formal parameters.
// Therefore in strict mode we allocate parameters as if 'arguments'
// were not used.
// If the parameter list is not simple, arguments isn't sloppy either.
uses_sloppy_arguments =
is_sloppy(language_mode()) && has_simple_parameters();
} else {
DCHECK(is_arrow_scope());
}
if (rest_parameter_ && !MustAllocate(rest_parameter_)) {
rest_parameter_ = NULL;
rest_parameter_ = nullptr;
}
// The same parameter may occur multiple times in the parameters_ list.
@ -1484,16 +1488,12 @@ void Scope::AllocateNonParameterLocalsAndDeclaredGlobals(Isolate* isolate) {
AllocateNonParameterLocal(isolate, rest_parameter_);
}
Variable* new_target_var =
LookupLocal(ast_value_factory_->new_target_string());
if (new_target_var != nullptr && MustAllocate(new_target_var)) {
new_target_ = new_target_var;
if (new_target_ != nullptr && !MustAllocate(new_target_)) {
new_target_ = nullptr;
}
Variable* this_function_var =
LookupLocal(ast_value_factory_->this_function_string());
if (this_function_var != nullptr && MustAllocate(this_function_var)) {
this_function_ = this_function_var;
if (this_function_ != nullptr && !MustAllocate(this_function_)) {
this_function_ = nullptr;
}
}