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Make the AstValueFactory more efficient and less memory hungry

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This makes strings_ and values_ in AstValueFactory a linked list through the AstString and AstValue objects. Additionally the CL computes whether strings are convertible to array indexes directly using the AstString's hash + literal bytes just as Name does, rather than indirecting over name if available.

BUG=

Review-Url: https://codereview.chromium.org/2225423002
Cr-Commit-Position: refs/heads/master@{#38536}
This commit is contained in:
verwaest 2016-08-10 04:55:01 -07:00 committed by Commit bot
parent d073777bbf
commit cbe5d41d88
4 changed files with 104 additions and 92 deletions
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90
src/ast/ast-value-factory.cc
View File

@ -97,7 +97,6 @@ void AstString::Internalize(Isolate* isolate) {
}
void AstRawString::Internalize(Isolate* isolate) {
if (!string_.is_null()) return;
if (literal_bytes_.length() == 0) {
string_ = isolate->factory()->empty_string();
} else {
@ -106,17 +105,18 @@ void AstRawString::Internalize(Isolate* isolate) {
}
}
bool AstRawString::AsArrayIndex(uint32_t* index,
HandleDereferenceMode deref_mode) const {
if (deref_mode == HandleDereferenceMode::kAllowed && !string_.is_null())
return string_->AsArrayIndex(index);
if (!is_one_byte() || literal_bytes_.length() == 0 ||
literal_bytes_.length() > String::kMaxArrayIndexSize)
return false;
bool AstRawString::AsArrayIndex(uint32_t* index) const {
// The StringHasher will set up the hash in such a way that we can use it to
// figure out whether the string is convertible to an array index.
if ((hash_ & Name::kIsNotArrayIndexMask) != 0) return false;
if (length() <= Name::kMaxCachedArrayIndexLength) {
*index = Name::ArrayIndexValueBits::decode(hash_);
} else {
OneByteStringStream stream(literal_bytes_);
return StringToArrayIndex(&stream, index);
CHECK(StringToArrayIndex(&stream, index));
}
return true;
}
bool AstRawString::IsOneByteEqualTo(const char* data) const {
int length = static_cast<int>(strlen(data));
@ -136,10 +136,10 @@ void AstConsString::Internalize(Isolate* isolate) {
.ToHandleChecked();
}
bool AstValue::IsPropertyName(HandleDereferenceMode deref_mode) const {
bool AstValue::IsPropertyName() const {
if (type_ == STRING) {
uint32_t index;
return !string_->AsArrayIndex(&index, deref_mode);
return !string_->AsArrayIndex(&index);
}
return false;
}
@ -251,7 +251,13 @@ const AstRawString* AstValueFactory::GetString(Handle<String> literal) {
}
}
isolate_ = saved_isolate;
if (isolate_) result->Internalize(isolate_);
if (strings_ != nullptr && isolate_) {
// Only the string we are creating is uninternalized at this point.
DCHECK_EQ(result, strings_);
DCHECK_NULL(strings_->next());
result->Internalize(isolate_);
ResetStrings();
}
return result;
}
@ -262,85 +268,68 @@ const AstConsString* AstValueFactory::NewConsString(
// the AstRawString will not be moved).
AstConsString* new_string = new (zone_) AstConsString(left, right);
CHECK(new_string != nullptr);
strings_.Add(new_string);
if (isolate_) {
new_string->Internalize(isolate_);
}
AddString(new_string);
return new_string;
}
void AstValueFactory::Internalize(Isolate* isolate) {
if (isolate_) {
DCHECK_NULL(strings_);
DCHECK_NULL(values_);
// Everything is already internalized.
return;
}
// Strings need to be internalized before values, because values refer to
// strings.
for (int i = 0; i < strings_.length(); ++i) {
strings_[i]->Internalize(isolate);
for (AstString* current = strings_; current != nullptr;) {
AstString* next = current->next();
current->Internalize(isolate);
current = next;
}
for (int i = 0; i < values_.length(); ++i) {
values_[i]->Internalize(isolate);
for (AstValue* current = values_; current != nullptr;) {
AstValue* next = current->next();
current->Internalize(isolate);
current = next;
}
isolate_ = isolate;
ResetStrings();
values_ = nullptr;
}
const AstValue* AstValueFactory::NewString(const AstRawString* string) {
AstValue* value = new (zone_) AstValue(string);
CHECK(string != nullptr);
if (isolate_) {
value->Internalize(isolate_);
}
values_.Add(value);
return value;
return AddValue(value);
}
const AstValue* AstValueFactory::NewSymbol(const char* name) {
AstValue* value = new (zone_) AstValue(name);
if (isolate_) {
value->Internalize(isolate_);
}
values_.Add(value);
return value;
return AddValue(value);
}
const AstValue* AstValueFactory::NewNumber(double number, bool with_dot) {
AstValue* value = new (zone_) AstValue(number, with_dot);
if (isolate_) {
value->Internalize(isolate_);
}
values_.Add(value);
return value;
return AddValue(value);
}
const AstValue* AstValueFactory::NewSmi(int number) {
AstValue* value =
new (zone_) AstValue(AstValue::SMI, number);
if (isolate_) {
value->Internalize(isolate_);
return AddValue(value);
}
values_.Add(value);
return value;
}
#define GENERATE_VALUE_GETTER(value, initializer) \
if (!value) { \
value = new (zone_) AstValue(initializer); \
if (isolate_) { \
value->Internalize(isolate_); \
} \
values_.Add(value); \
value = AddValue(new (zone_) AstValue(initializer)); \
} \
return value;
const AstValue* AstValueFactory::NewBoolean(bool b) {
if (b) {
GENERATE_VALUE_GETTER(true_value_, true);
@ -384,10 +373,7 @@ AstRawString* AstValueFactory::GetString(uint32_t hash, bool is_one_byte,
is_one_byte, Vector<const byte>(new_literal_bytes, length), hash);
CHECK(new_string != nullptr);
entry->key = new_string;
strings_.Add(new_string);
if (isolate_) {
new_string->Internalize(isolate_);
}
AddString(new_string);
entry->value = reinterpret_cast<void*>(1);
}
return reinterpret_cast<AstRawString*>(entry->key);

71
src/ast/ast-value-factory.h
View File

@ -43,9 +43,7 @@ namespace internal {
class AstString : public ZoneObject {
public:
explicit AstString(bool is_raw)
: bit_field_(IsRawStringBits::encode(is_raw)) {}
~AstString() {}
: next_(nullptr), bit_field_(IsRawStringBits::encode(is_raw)) {}
int length() const;
bool IsEmpty() const { return length() == 0; }
@ -59,9 +57,13 @@ class AstString : public ZoneObject {
return string_;
}
AstString** next_location() { return &next_; }
AstString* next() const { return next_; }
protected:
// This is null until the string is internalized.
// Handle<String>::null() until internalized.
Handle<String> string_;
AstString* next_;
// Poor-man's virtual dispatch to AstRawString / AstConsString. Takes less
// memory.
class IsRawStringBits : public BitField<bool, 0, 1> {};
@ -80,8 +82,7 @@ class AstRawString final : public AstString {
void Internalize(Isolate* isolate);
bool AsArrayIndex(uint32_t* index, HandleDereferenceMode deref_mode =
HandleDereferenceMode::kAllowed) const;
bool AsArrayIndex(uint32_t* index) const;
// The string is not null-terminated, use length() to find out the length.
const unsigned char* raw_data() const {
@ -181,8 +182,7 @@ class AstValue : public ZoneObject {
return type_ == STRING && string_ == string;
}
bool IsPropertyName(
HandleDereferenceMode deref_mode = HandleDereferenceMode::kAllowed) const;
bool IsPropertyName() const;
bool BooleanValue() const;
@ -203,6 +203,8 @@ class AstValue : public ZoneObject {
DCHECK(!value_.is_null());
return value_;
}
AstValue* next() const { return next_; }
void set_next(AstValue* next) { next_ = next; }
private:
friend class AstValueFactory;
@ -219,11 +221,15 @@ class AstValue : public ZoneObject {
THE_HOLE
};
explicit AstValue(const AstRawString* s) : type_(STRING) { string_ = s; }
explicit AstValue(const AstRawString* s) : type_(STRING), next_(nullptr) {
string_ = s;
}
explicit AstValue(const char* name) : type_(SYMBOL) { symbol_name_ = name; }
explicit AstValue(const char* name) : type_(SYMBOL), next_(nullptr) {
symbol_name_ = name;
}
explicit AstValue(double n, bool with_dot) {
explicit AstValue(double n, bool with_dot) : next_(nullptr) {
if (with_dot) {
type_ = NUMBER_WITH_DOT;
number_ = n;
@ -239,14 +245,14 @@ class AstValue : public ZoneObject {
}
}
AstValue(Type t, int i) : type_(t) {
AstValue(Type t, int i) : type_(t), next_(nullptr) {
DCHECK(type_ == SMI);
smi_ = i;
}
explicit AstValue(bool b) : type_(BOOLEAN) { bool_ = b; }
explicit AstValue(bool b) : type_(BOOLEAN), next_(nullptr) { bool_ = b; }
explicit AstValue(Type t) : type_(t) {
explicit AstValue(Type t) : type_(t), next_(nullptr) {
DCHECK(t == NULL_TYPE || t == UNDEFINED || t == THE_HOLE);
}
@ -258,12 +264,13 @@ class AstValue : public ZoneObject {
double number_;
int smi_;
bool bool_;
ZoneList<const AstRawString*>* strings_;
const AstRawString* strings_;
const char* symbol_name_;
};
// Internalized value (empty before internalized).
// Handle<String>::null() until internalized.
Handle<Object> value_;
AstValue* next_;
};
@ -316,9 +323,12 @@ class AstValueFactory {
public:
AstValueFactory(Zone* zone, uint32_t hash_seed)
: string_table_(AstRawStringCompare),
values_(nullptr),
strings_end_(&strings_),
zone_(zone),
isolate_(NULL),
hash_seed_(hash_seed) {
ResetStrings();
#define F(name, str) name##_string_ = NULL;
STRING_CONSTANTS(F)
#undef F
@ -373,6 +383,28 @@ class AstValueFactory {
const AstValue* NewTheHole();
private:
AstValue* AddValue(AstValue* value) {
if (isolate_) {
value->Internalize(isolate_);
} else {
value->set_next(values_);
values_ = value;
}
return value;
}
AstString* AddString(AstString* string) {
if (isolate_) {
string->Internalize(isolate_);
} else {
*strings_end_ = string;
strings_end_ = string->next_location();
}
return string;
}
void ResetStrings() {
strings_ = nullptr;
strings_end_ = &strings_;
}
AstRawString* GetOneByteStringInternal(Vector<const uint8_t> literal);
AstRawString* GetTwoByteStringInternal(Vector<const uint16_t> literal);
AstRawString* GetString(uint32_t hash, bool is_one_byte,
@ -384,8 +416,11 @@ class AstValueFactory {
base::HashMap string_table_;
// For keeping track of all AstValues and AstRawStrings we've created (so that
// they can be internalized later).
List<AstValue*> values_;
List<AstString*> strings_;
AstValue* values_;
// We need to keep track of strings_ in order, since cons strings require
// their members to be internalized first.
AstString* strings_;
AstString** strings_end_;
Zone* zone_;
Isolate* isolate_;

6
src/ast/ast.cc
View File

@ -74,8 +74,8 @@ bool Expression::IsStringLiteral() const {
return IsLiteral() && AsLiteral()->value()->IsString();
}
bool Expression::IsPropertyName(HandleDereferenceMode deref_mode) const {
return IsLiteral() && AsLiteral()->IsPropertyName(deref_mode);
bool Expression::IsPropertyName() const {
return IsLiteral() && AsLiteral()->IsPropertyName();
}
bool Expression::IsNullLiteral() const {
@ -933,7 +933,7 @@ Call::CallType Call::GetCallType(Isolate* isolate,
Property* property = expression()->AsProperty();
if (property != nullptr) {
bool is_super = property->IsSuperAccess();
if (property->key()->IsPropertyName(deref_mode)) {
if (property->key()->IsPropertyName()) {
return is_super ? NAMED_SUPER_PROPERTY_CALL : NAMED_PROPERTY_CALL;
} else {
return is_super ? KEYED_SUPER_PROPERTY_CALL : KEYED_PROPERTY_CALL;

21
src/ast/ast.h
View File

@ -314,10 +314,7 @@ class Expression : public AstNode {
// Symbols that cannot be parsed as array indices are considered property
// names. We do not treat symbols that can be array indexes as property
// names because [] for string objects is handled only by keyed ICs.
// Produces the same result whether |deref_mode| is kAllowed or kDisallowed,
// although may be faster with kAllowed.
bool IsPropertyName(
HandleDereferenceMode deref_mode = HandleDereferenceMode::kAllowed) const;
bool IsPropertyName() const;
// True iff the expression is a class or function expression without
// a syntactic name.
@ -1196,15 +1193,11 @@ class SloppyBlockFunctionStatement final : public Statement {
class Literal final : public Expression {
public:
// Returns true if literal represents a property name (i.e. cannot be parsed
// as array indices). Produces the same result whether |deref_mode| is
// kAllowed or kDisallowed, although may be faster with kAllowed.
bool IsPropertyName(HandleDereferenceMode deref_mode =
HandleDereferenceMode::kAllowed) const {
return value_->IsPropertyName(deref_mode);
}
// as array indices).
bool IsPropertyName() const { return value_->IsPropertyName(); }
Handle<String> AsPropertyName() {
DCHECK(IsPropertyName(HandleDereferenceMode::kDisallowed));
DCHECK(IsPropertyName());
return Handle<String>::cast(value());
}
@ -1744,15 +1737,13 @@ class Property final : public Expression {
return property_feedback_slot_;
}
// Returns the properties assign type. Produces the same result whether
// |deref_mode| is kAllowed or kDisallowed, although may be faster with
// kAllowed.
// Returns the properties assign type.
static LhsKind GetAssignType(
Property* property,
HandleDereferenceMode deref_mode = HandleDereferenceMode::kAllowed) {
if (property == NULL) return VARIABLE;
bool super_access = property->IsSuperAccess();
return (property->key()->IsPropertyName(deref_mode))
return (property->key()->IsPropertyName())
? (super_access ? NAMED_SUPER_PROPERTY : NAMED_PROPERTY)
: (super_access ? KEYED_SUPER_PROPERTY : KEYED_PROPERTY);
}