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cobalt / cobalt / f309f9a11671768c59005e71c207e268484cbe9f / . / src / third_party / v8 / src / builtins / builtins-string-gen.cc
blob: aa982a3c1bd71733a25e27e7695d3c4f56ae0fd2 [file] [log] [blame]
// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/builtins/builtins-string-gen.h"
#include "src/builtins/builtins-regexp-gen.h"
#include "src/builtins/builtins-utils-gen.h"
#include "src/builtins/builtins.h"
#include "src/codegen/code-factory.h"
#include "src/execution/protectors.h"
#include "src/heap/factory-inl.h"
#include "src/heap/heap-inl.h"
#include "src/logging/counters.h"
#include "src/objects/objects.h"
#include "src/objects/property-cell.h"
namespace v8 {
namespace internal {
using Node = compiler::Node;
TNode<RawPtrT> StringBuiltinsAssembler::DirectStringData(
TNode<String> string, TNode<Word32T> string_instance_type) {
// Compute the effective offset of the first character.
TVARIABLE(RawPtrT, var_data);
Label if_sequential(this), if_external(this), if_join(this);
Branch(Word32Equal(Word32And(string_instance_type,
Int32Constant(kStringRepresentationMask)),
Int32Constant(kSeqStringTag)),
&if_sequential, &if_external);
BIND(&if_sequential);
{
var_data = RawPtrAdd(
ReinterpretCast<RawPtrT>(BitcastTaggedToWord(string)),
IntPtrConstant(SeqOneByteString::kHeaderSize - kHeapObjectTag));
Goto(&if_join);
}
BIND(&if_external);
{
// This is only valid for ExternalStrings where the resource data
// pointer is cached (i.e. no uncached external strings).
CSA_ASSERT(this, Word32NotEqual(
Word32And(string_instance_type,
Int32Constant(kUncachedExternalStringMask)),
Int32Constant(kUncachedExternalStringTag)));
var_data = LoadExternalStringResourceDataPtr(CAST(string));
Goto(&if_join);
}
BIND(&if_join);
return var_data.value();
}
void StringBuiltinsAssembler::DispatchOnStringEncodings(
TNode<Word32T> const lhs_instance_type,
TNode<Word32T> const rhs_instance_type, Label* if_one_one,
Label* if_one_two, Label* if_two_one, Label* if_two_two) {
STATIC_ASSERT(kStringEncodingMask == 0x8);
STATIC_ASSERT(kTwoByteStringTag == 0x0);
STATIC_ASSERT(kOneByteStringTag == 0x8);
// First combine the encodings.
const TNode<Int32T> encoding_mask = Int32Constant(kStringEncodingMask);
const TNode<Word32T> lhs_encoding =
Word32And(lhs_instance_type, encoding_mask);
const TNode<Word32T> rhs_encoding =
Word32And(rhs_instance_type, encoding_mask);
const TNode<Word32T> combined_encodings =
Word32Or(lhs_encoding, Word32Shr(rhs_encoding, 1));
// Then dispatch on the combined encoding.
Label unreachable(this, Label::kDeferred);
int32_t values[] = {
kOneByteStringTag | (kOneByteStringTag >> 1),
kOneByteStringTag | (kTwoByteStringTag >> 1),
kTwoByteStringTag | (kOneByteStringTag >> 1),
kTwoByteStringTag | (kTwoByteStringTag >> 1),
};
Label* labels[] = {
if_one_one, if_one_two, if_two_one, if_two_two,
};
STATIC_ASSERT(arraysize(values) == arraysize(labels));
Switch(combined_encodings, &unreachable, values, labels, arraysize(values));
BIND(&unreachable);
Unreachable();
}
template <typename SubjectChar, typename PatternChar>
TNode<IntPtrT> StringBuiltinsAssembler::CallSearchStringRaw(
const TNode<RawPtrT> subject_ptr, const TNode<IntPtrT> subject_length,
const TNode<RawPtrT> search_ptr, const TNode<IntPtrT> search_length,
const TNode<IntPtrT> start_position) {
const TNode<ExternalReference> function_addr = ExternalConstant(
ExternalReference::search_string_raw<SubjectChar, PatternChar>());
const TNode<ExternalReference> isolate_ptr =
ExternalConstant(ExternalReference::isolate_address(isolate()));
MachineType type_ptr = MachineType::Pointer();
MachineType type_intptr = MachineType::IntPtr();
const TNode<IntPtrT> result = UncheckedCast<IntPtrT>(CallCFunction(
function_addr, type_intptr, std::make_pair(type_ptr, isolate_ptr),
std::make_pair(type_ptr, subject_ptr),
std::make_pair(type_intptr, subject_length),
std::make_pair(type_ptr, search_ptr),
std::make_pair(type_intptr, search_length),
std::make_pair(type_intptr, start_position)));
return result;
}
TNode<RawPtrT> StringBuiltinsAssembler::PointerToStringDataAtIndex(
TNode<RawPtrT> string_data, TNode<IntPtrT> index,
String::Encoding encoding) {
const ElementsKind kind = (encoding == String::ONE_BYTE_ENCODING)
? UINT8_ELEMENTS
: UINT16_ELEMENTS;
TNode<IntPtrT> offset_in_bytes = ElementOffsetFromIndex(index, kind);
return RawPtrAdd(string_data, offset_in_bytes);
}
void StringBuiltinsAssembler::GenerateStringEqual(TNode<String> left,
TNode<String> right) {
TVARIABLE(String, var_left, left);
TVARIABLE(String, var_right, right);
Label if_equal(this), if_notequal(this), if_indirect(this, Label::kDeferred),
restart(this, {&var_left, &var_right});
TNode<IntPtrT> lhs_length = LoadStringLengthAsWord(left);
TNode<IntPtrT> rhs_length = LoadStringLengthAsWord(right);
// Strings with different lengths cannot be equal.
GotoIf(WordNotEqual(lhs_length, rhs_length), &if_notequal);
Goto(&restart);
BIND(&restart);
TNode<String> lhs = var_left.value();
TNode<String> rhs = var_right.value();
TNode<Uint16T> lhs_instance_type = LoadInstanceType(lhs);
TNode<Uint16T> rhs_instance_type = LoadInstanceType(rhs);
StringEqual_Core(lhs, lhs_instance_type, rhs, rhs_instance_type, lhs_length,
&if_equal, &if_notequal, &if_indirect);
BIND(&if_indirect);
{
// Try to unwrap indirect strings, restart the above attempt on success.
MaybeDerefIndirectStrings(&var_left, lhs_instance_type, &var_right,
rhs_instance_type, &restart);
TailCallRuntime(Runtime::kStringEqual, NoContextConstant(), lhs, rhs);
}
BIND(&if_equal);
Return(TrueConstant());
BIND(&if_notequal);
Return(FalseConstant());
}
void StringBuiltinsAssembler::StringEqual_Core(
TNode<String> lhs, TNode<Word32T> lhs_instance_type, TNode<String> rhs,
TNode<Word32T> rhs_instance_type, TNode<IntPtrT> length, Label* if_equal,
Label* if_not_equal, Label* if_indirect) {
CSA_ASSERT(this, WordEqual(LoadStringLengthAsWord(lhs), length));
CSA_ASSERT(this, WordEqual(LoadStringLengthAsWord(rhs), length));
// Fast check to see if {lhs} and {rhs} refer to the same String object.
GotoIf(TaggedEqual(lhs, rhs), if_equal);
// Combine the instance types into a single 16-bit value, so we can check
// both of them at once.
TNode<Word32T> both_instance_types = Word32Or(
lhs_instance_type, Word32Shl(rhs_instance_type, Int32Constant(8)));
// Check if both {lhs} and {rhs} are internalized. Since we already know
// that they're not the same object, they're not equal in that case.
int const kBothInternalizedMask =
kIsNotInternalizedMask | (kIsNotInternalizedMask << 8);
int const kBothInternalizedTag = kInternalizedTag | (kInternalizedTag << 8);
GotoIf(Word32Equal(Word32And(both_instance_types,
Int32Constant(kBothInternalizedMask)),
Int32Constant(kBothInternalizedTag)),
if_not_equal);
// Check if both {lhs} and {rhs} are direct strings, and that in case of
// ExternalStrings the data pointer is cached.
STATIC_ASSERT(kUncachedExternalStringTag != 0);
STATIC_ASSERT(kIsIndirectStringTag != 0);
int const kBothDirectStringMask =
kIsIndirectStringMask | kUncachedExternalStringMask |
((kIsIndirectStringMask | kUncachedExternalStringMask) << 8);
GotoIfNot(Word32Equal(Word32And(both_instance_types,
Int32Constant(kBothDirectStringMask)),
Int32Constant(0)),
if_indirect);
// Dispatch based on the {lhs} and {rhs} string encoding.
int const kBothStringEncodingMask =
kStringEncodingMask | (kStringEncodingMask << 8);
int const kOneOneByteStringTag = kOneByteStringTag | (kOneByteStringTag << 8);
int const kTwoTwoByteStringTag = kTwoByteStringTag | (kTwoByteStringTag << 8);
int const kOneTwoByteStringTag = kOneByteStringTag | (kTwoByteStringTag << 8);
Label if_oneonebytestring(this), if_twotwobytestring(this),
if_onetwobytestring(this), if_twoonebytestring(this);
TNode<Word32T> masked_instance_types =
Word32And(both_instance_types, Int32Constant(kBothStringEncodingMask));
GotoIf(
Word32Equal(masked_instance_types, Int32Constant(kOneOneByteStringTag)),
&if_oneonebytestring);
GotoIf(
Word32Equal(masked_instance_types, Int32Constant(kTwoTwoByteStringTag)),
&if_twotwobytestring);
Branch(
Word32Equal(masked_instance_types, Int32Constant(kOneTwoByteStringTag)),
&if_onetwobytestring, &if_twoonebytestring);
BIND(&if_oneonebytestring);
StringEqual_Loop(lhs, lhs_instance_type, MachineType::Uint8(), rhs,
rhs_instance_type, MachineType::Uint8(), length, if_equal,
if_not_equal);
BIND(&if_twotwobytestring);
StringEqual_Loop(lhs, lhs_instance_type, MachineType::Uint16(), rhs,
rhs_instance_type, MachineType::Uint16(), length, if_equal,
if_not_equal);
BIND(&if_onetwobytestring);
StringEqual_Loop(lhs, lhs_instance_type, MachineType::Uint8(), rhs,
rhs_instance_type, MachineType::Uint16(), length, if_equal,
if_not_equal);
BIND(&if_twoonebytestring);
StringEqual_Loop(lhs, lhs_instance_type, MachineType::Uint16(), rhs,
rhs_instance_type, MachineType::Uint8(), length, if_equal,
if_not_equal);
}
void StringBuiltinsAssembler::StringEqual_Loop(
TNode<String> lhs, TNode<Word32T> lhs_instance_type, MachineType lhs_type,
TNode<String> rhs, TNode<Word32T> rhs_instance_type, MachineType rhs_type,
TNode<IntPtrT> length, Label* if_equal, Label* if_not_equal) {
CSA_ASSERT(this, WordEqual(LoadStringLengthAsWord(lhs), length));
CSA_ASSERT(this, WordEqual(LoadStringLengthAsWord(rhs), length));
// Compute the effective offset of the first character.
TNode<RawPtrT> lhs_data = DirectStringData(lhs, lhs_instance_type);
TNode<RawPtrT> rhs_data = DirectStringData(rhs, rhs_instance_type);
// Loop over the {lhs} and {rhs} strings to see if they are equal.
TVARIABLE(IntPtrT, var_offset, IntPtrConstant(0));
Label loop(this, &var_offset);
Goto(&loop);
BIND(&loop);
{
// If {offset} equals {end}, no difference was found, so the
// strings are equal.
GotoIf(WordEqual(var_offset.value(), length), if_equal);
// Load the next characters from {lhs} and {rhs}.
TNode<Word32T> lhs_value = UncheckedCast<Word32T>(
Load(lhs_type, lhs_data,
WordShl(var_offset.value(),
ElementSizeLog2Of(lhs_type.representation()))));
TNode<Word32T> rhs_value = UncheckedCast<Word32T>(
Load(rhs_type, rhs_data,
WordShl(var_offset.value(),
ElementSizeLog2Of(rhs_type.representation()))));
// Check if the characters match.
GotoIf(Word32NotEqual(lhs_value, rhs_value), if_not_equal);
// Advance to next character.
var_offset = IntPtrAdd(var_offset.value(), IntPtrConstant(1));
Goto(&loop);
}
}
TNode<String> StringBuiltinsAssembler::StringFromSingleUTF16EncodedCodePoint(
TNode<Int32T> codepoint) {
TVARIABLE(String, var_result, EmptyStringConstant());
Label if_isword16(this), if_isword32(this), return_result(this);
Branch(Uint32LessThan(codepoint, Int32Constant(0x10000)), &if_isword16,
&if_isword32);
BIND(&if_isword16);
{
var_result = StringFromSingleCharCode(codepoint);
Goto(&return_result);
}
BIND(&if_isword32);
{
TNode<String> value = AllocateSeqTwoByteString(2);
StoreNoWriteBarrier(
MachineRepresentation::kWord32, value,
IntPtrConstant(SeqTwoByteString::kHeaderSize - kHeapObjectTag),
codepoint);
var_result = value;
Goto(&return_result);
}
BIND(&return_result);
return var_result.value();
}
TNode<String> StringBuiltinsAssembler::AllocateConsString(TNode<Uint32T> length,
TNode<String> left,
TNode<String> right) {
// Added string can be a cons string.
Comment("Allocating ConsString");
TNode<Int32T> left_instance_type = LoadInstanceType(left);
TNode<Int32T> right_instance_type = LoadInstanceType(right);
// Determine the resulting ConsString map to use depending on whether
// any of {left} or {right} has two byte encoding.
STATIC_ASSERT(kOneByteStringTag != 0);
STATIC_ASSERT(kTwoByteStringTag == 0);
TNode<Int32T> combined_instance_type =
Word32And(left_instance_type, right_instance_type);
TNode<Map> result_map = CAST(Select<Object>(
IsSetWord32(combined_instance_type, kStringEncodingMask),
[=] { return ConsOneByteStringMapConstant(); },
[=] { return ConsStringMapConstant(); }));
TNode<HeapObject> result = AllocateInNewSpace(ConsString::kSize);
StoreMapNoWriteBarrier(result, result_map);
StoreObjectFieldNoWriteBarrier(result, ConsString::kLengthOffset, length);
StoreObjectFieldNoWriteBarrier(result, ConsString::kHashFieldOffset,
Int32Constant(String::kEmptyHashField));
StoreObjectFieldNoWriteBarrier(result, ConsString::kFirstOffset, left);
StoreObjectFieldNoWriteBarrier(result, ConsString::kSecondOffset, right);
return CAST(result);
}
TNode<String> StringBuiltinsAssembler::StringAdd(
TNode<ContextOrEmptyContext> context, TNode<String> left,
TNode<String> right) {
CSA_ASSERT(this, IsZeroOrContext(context));
TVARIABLE(String, result);
Label check_right(this), runtime(this, Label::kDeferred), cons(this),
done(this, &result), done_native(this, &result);
Counters* counters = isolate()->counters();
TNode<Uint32T> left_length = LoadStringLengthAsWord32(left);
GotoIfNot(Word32Equal(left_length, Uint32Constant(0)), &check_right);
result = right;
Goto(&done_native);
BIND(&check_right);
TNode<Uint32T> right_length = LoadStringLengthAsWord32(right);
GotoIfNot(Word32Equal(right_length, Uint32Constant(0)), &cons);
result = left;
Goto(&done_native);
BIND(&cons);
{
TNode<Uint32T> new_length = Uint32Add(left_length, right_length);
// If new length is greater than String::kMaxLength, goto runtime to
// throw. Note: we also need to invalidate the string length protector, so
// can't just throw here directly.
GotoIf(Uint32GreaterThan(new_length, Uint32Constant(String::kMaxLength)),
&runtime);
TVARIABLE(String, var_left, left);
TVARIABLE(String, var_right, right);
Label non_cons(this, {&var_left, &var_right});
Label slow(this, Label::kDeferred);
GotoIf(Uint32LessThan(new_length, Uint32Constant(ConsString::kMinLength)),
&non_cons);
result =
AllocateConsString(new_length, var_left.value(), var_right.value());
Goto(&done_native);
BIND(&non_cons);
Comment("Full string concatenate");
TNode<Int32T> left_instance_type = LoadInstanceType(var_left.value());
TNode<Int32T> right_instance_type = LoadInstanceType(var_right.value());
// Compute intersection and difference of instance types.
TNode<Int32T> ored_instance_types =
Word32Or(left_instance_type, right_instance_type);
TNode<Word32T> xored_instance_types =
Word32Xor(left_instance_type, right_instance_type);
// Check if both strings have the same encoding and both are sequential.
GotoIf(IsSetWord32(xored_instance_types, kStringEncodingMask), &runtime);
GotoIf(IsSetWord32(ored_instance_types, kStringRepresentationMask), &slow);
TNode<IntPtrT> word_left_length = Signed(ChangeUint32ToWord(left_length));
TNode<IntPtrT> word_right_length = Signed(ChangeUint32ToWord(right_length));
Label two_byte(this);
GotoIf(Word32Equal(Word32And(ored_instance_types,
Int32Constant(kStringEncodingMask)),
Int32Constant(kTwoByteStringTag)),
&two_byte);
// One-byte sequential string case
result = AllocateSeqOneByteString(new_length);
CopyStringCharacters(var_left.value(), result.value(), IntPtrConstant(0),
IntPtrConstant(0), word_left_length,
String::ONE_BYTE_ENCODING, String::ONE_BYTE_ENCODING);
CopyStringCharacters(var_right.value(), result.value(), IntPtrConstant(0),
word_left_length, word_right_length,
String::ONE_BYTE_ENCODING, String::ONE_BYTE_ENCODING);
Goto(&done_native);
BIND(&two_byte);
{
// Two-byte sequential string case
result = AllocateSeqTwoByteString(new_length);
CopyStringCharacters(var_left.value(), result.value(), IntPtrConstant(0),
IntPtrConstant(0), word_left_length,
String::TWO_BYTE_ENCODING,
String::TWO_BYTE_ENCODING);
CopyStringCharacters(var_right.value(), result.value(), IntPtrConstant(0),
word_left_length, word_right_length,
String::TWO_BYTE_ENCODING,
String::TWO_BYTE_ENCODING);
Goto(&done_native);
}
BIND(&slow);
{
// Try to unwrap indirect strings, restart the above attempt on success.
MaybeDerefIndirectStrings(&var_left, left_instance_type, &var_right,
right_instance_type, &non_cons);
Goto(&runtime);
}
}
BIND(&runtime);
{
result = CAST(CallRuntime(Runtime::kStringAdd, context, left, right));
Goto(&done);
}
BIND(&done_native);
{
IncrementCounter(counters->string_add_native(), 1);
Goto(&done);
}
BIND(&done);
return result.value();
}
void StringBuiltinsAssembler::BranchIfCanDerefIndirectString(
TNode<String> string, TNode<Int32T> instance_type, Label* can_deref,
Label* cannot_deref) {
TNode<Int32T> representation =
Word32And(instance_type, Int32Constant(kStringRepresentationMask));
GotoIf(Word32Equal(representation, Int32Constant(kThinStringTag)), can_deref);
GotoIf(Word32NotEqual(representation, Int32Constant(kConsStringTag)),
cannot_deref);
// Cons string.
TNode<String> rhs =
LoadObjectField<String>(string, ConsString::kSecondOffset);
GotoIf(IsEmptyString(rhs), can_deref);
Goto(cannot_deref);
}
void StringBuiltinsAssembler::DerefIndirectString(TVariable<String>* var_string,
TNode<Int32T> instance_type) {
#ifdef DEBUG
Label can_deref(this), cannot_deref(this);
BranchIfCanDerefIndirectString(var_string->value(), instance_type, &can_deref,
&cannot_deref);
BIND(&cannot_deref);
DebugBreak(); // Should be able to dereference string.
Goto(&can_deref);
BIND(&can_deref);
#endif // DEBUG
STATIC_ASSERT(static_cast<int>(ThinString::kActualOffset) ==
static_cast<int>(ConsString::kFirstOffset));
*var_string =
LoadObjectField<String>(var_string->value(), ThinString::kActualOffset);
}
void StringBuiltinsAssembler::MaybeDerefIndirectString(
TVariable<String>* var_string, TNode<Int32T> instance_type,
Label* did_deref, Label* cannot_deref) {
Label deref(this);
BranchIfCanDerefIndirectString(var_string->value(), instance_type, &deref,
cannot_deref);
BIND(&deref);
{
DerefIndirectString(var_string, instance_type);
Goto(did_deref);
}
}
void StringBuiltinsAssembler::MaybeDerefIndirectStrings(
TVariable<String>* var_left, TNode<Int32T> left_instance_type,
TVariable<String>* var_right, TNode<Int32T> right_instance_type,
Label* did_something) {
Label did_nothing_left(this), did_something_left(this),
didnt_do_anything(this);
MaybeDerefIndirectString(var_left, left_instance_type, &did_something_left,
&did_nothing_left);
BIND(&did_something_left);
{
MaybeDerefIndirectString(var_right, right_instance_type, did_something,
did_something);
}
BIND(&did_nothing_left);
{
MaybeDerefIndirectString(var_right, right_instance_type, did_something,
&didnt_do_anything);
}
BIND(&didnt_do_anything);
// Fall through if neither string was an indirect string.
}
TNode<String> StringBuiltinsAssembler::DerefIndirectString(
TNode<String> string, TNode<Int32T> instance_type, Label* cannot_deref) {
Label deref(this);
BranchIfCanDerefIndirectString(string, instance_type, &deref, cannot_deref);
BIND(&deref);
STATIC_ASSERT(static_cast<int>(ThinString::kActualOffset) ==
static_cast<int>(ConsString::kFirstOffset));
return LoadObjectField<String>(string, ThinString::kActualOffset);
}
TF_BUILTIN(StringAdd_CheckNone, StringBuiltinsAssembler) {
auto left = Parameter<String>(Descriptor::kLeft);
auto right = Parameter<String>(Descriptor::kRight);
TNode<ContextOrEmptyContext> context =
UncheckedParameter<ContextOrEmptyContext>(Descriptor::kContext);
CSA_ASSERT(this, IsZeroOrContext(context));
Return(StringAdd(context, left, right));
}
TF_BUILTIN(SubString, StringBuiltinsAssembler) {
auto string = Parameter<String>(Descriptor::kString);
auto from = Parameter<Smi>(Descriptor::kFrom);
auto to = Parameter<Smi>(Descriptor::kTo);
Return(SubString(string, SmiUntag(from), SmiUntag(to)));
}
void StringBuiltinsAssembler::GenerateStringRelationalComparison(
TNode<String> left, TNode<String> right, Operation op) {
TVARIABLE(String, var_left, left);
TVARIABLE(String, var_right, right);
Label if_less(this), if_equal(this), if_greater(this);
Label restart(this, {&var_left, &var_right});
Goto(&restart);
BIND(&restart);
TNode<String> lhs = var_left.value();
TNode<String> rhs = var_right.value();
// Fast check to see if {lhs} and {rhs} refer to the same String object.
GotoIf(TaggedEqual(lhs, rhs), &if_equal);
// Load instance types of {lhs} and {rhs}.
TNode<Uint16T> lhs_instance_type = LoadInstanceType(lhs);
TNode<Uint16T> rhs_instance_type = LoadInstanceType(rhs);
// Combine the instance types into a single 16-bit value, so we can check
// both of them at once.
TNode<Int32T> both_instance_types = Word32Or(
lhs_instance_type, Word32Shl(rhs_instance_type, Int32Constant(8)));
// Check that both {lhs} and {rhs} are flat one-byte strings.
int const kBothSeqOneByteStringMask =
kStringEncodingMask | kStringRepresentationMask |
((kStringEncodingMask | kStringRepresentationMask) << 8);
int const kBothSeqOneByteStringTag =
kOneByteStringTag | kSeqStringTag |
((kOneByteStringTag | kSeqStringTag) << 8);
Label if_bothonebyteseqstrings(this), if_notbothonebyteseqstrings(this);
Branch(Word32Equal(Word32And(both_instance_types,
Int32Constant(kBothSeqOneByteStringMask)),
Int32Constant(kBothSeqOneByteStringTag)),
&if_bothonebyteseqstrings, &if_notbothonebyteseqstrings);
BIND(&if_bothonebyteseqstrings);
{
// Load the length of {lhs} and {rhs}.
TNode<IntPtrT> lhs_length = LoadStringLengthAsWord(lhs);
TNode<IntPtrT> rhs_length = LoadStringLengthAsWord(rhs);
// Determine the minimum length.
TNode<IntPtrT> length = IntPtrMin(lhs_length, rhs_length);
// Compute the effective offset of the first character.
TNode<IntPtrT> begin =
IntPtrConstant(SeqOneByteString::kHeaderSize - kHeapObjectTag);
// Compute the first offset after the string from the length.
TNode<IntPtrT> end = IntPtrAdd(begin, length);
// Loop over the {lhs} and {rhs} strings to see if they are equal.
TVARIABLE(IntPtrT, var_offset, begin);
Label loop(this, &var_offset);
Goto(&loop);
BIND(&loop);
{
// Check if {offset} equals {end}.
Label if_done(this), if_notdone(this);
Branch(WordEqual(var_offset.value(), end), &if_done, &if_notdone);
BIND(&if_notdone);
{
// Load the next characters from {lhs} and {rhs}.
TNode<Uint8T> lhs_value = Load<Uint8T>(lhs, var_offset.value());
TNode<Uint8T> rhs_value = Load<Uint8T>(rhs, var_offset.value());
// Check if the characters match.
Label if_valueissame(this), if_valueisnotsame(this);
Branch(Word32Equal(lhs_value, rhs_value), &if_valueissame,
&if_valueisnotsame);
BIND(&if_valueissame);
{
// Advance to next character.
var_offset = IntPtrAdd(var_offset.value(), IntPtrConstant(1));
}
Goto(&loop);
BIND(&if_valueisnotsame);
Branch(Uint32LessThan(lhs_value, rhs_value), &if_less, &if_greater);
}
BIND(&if_done);
{
// All characters up to the min length are equal, decide based on
// string length.
GotoIf(IntPtrEqual(lhs_length, rhs_length), &if_equal);
Branch(IntPtrLessThan(lhs_length, rhs_length), &if_less, &if_greater);
}
}
}
BIND(&if_notbothonebyteseqstrings);
{
// Try to unwrap indirect strings, restart the above attempt on success.
MaybeDerefIndirectStrings(&var_left, lhs_instance_type, &var_right,
rhs_instance_type, &restart);
// TODO(bmeurer): Add support for two byte string relational comparisons.
switch (op) {
case Operation::kLessThan:
TailCallRuntime(Runtime::kStringLessThan, NoContextConstant(), lhs,
rhs);
break;
case Operation::kLessThanOrEqual:
TailCallRuntime(Runtime::kStringLessThanOrEqual, NoContextConstant(),
lhs, rhs);
break;
case Operation::kGreaterThan:
TailCallRuntime(Runtime::kStringGreaterThan, NoContextConstant(), lhs,
rhs);
break;
case Operation::kGreaterThanOrEqual:
TailCallRuntime(Runtime::kStringGreaterThanOrEqual, NoContextConstant(),
lhs, rhs);
break;
default:
UNREACHABLE();
}
}
BIND(&if_less);
switch (op) {
case Operation::kLessThan:
case Operation::kLessThanOrEqual:
Return(TrueConstant());
break;
case Operation::kGreaterThan:
case Operation::kGreaterThanOrEqual:
Return(FalseConstant());
break;
default:
UNREACHABLE();
}
BIND(&if_equal);
switch (op) {
case Operation::kLessThan:
case Operation::kGreaterThan:
Return(FalseConstant());
break;
case Operation::kLessThanOrEqual:
case Operation::kGreaterThanOrEqual:
Return(TrueConstant());
break;
default:
UNREACHABLE();
}
BIND(&if_greater);
switch (op) {
case Operation::kLessThan:
case Operation::kLessThanOrEqual:
Return(FalseConstant());
break;
case Operation::kGreaterThan:
case Operation::kGreaterThanOrEqual:
Return(TrueConstant());
break;
default:
UNREACHABLE();
}
}
TF_BUILTIN(StringEqual, StringBuiltinsAssembler) {
auto left = Parameter<String>(Descriptor::kLeft);
auto right = Parameter<String>(Descriptor::kRight);
GenerateStringEqual(left, right);
}
TF_BUILTIN(StringLessThan, StringBuiltinsAssembler) {
auto left = Parameter<String>(Descriptor::kLeft);
auto right = Parameter<String>(Descriptor::kRight);
GenerateStringRelationalComparison(left, right, Operation::kLessThan);
}
TF_BUILTIN(StringLessThanOrEqual, StringBuiltinsAssembler) {
auto left = Parameter<String>(Descriptor::kLeft);
auto right = Parameter<String>(Descriptor::kRight);
GenerateStringRelationalComparison(left, right, Operation::kLessThanOrEqual);
}
TF_BUILTIN(StringGreaterThan, StringBuiltinsAssembler) {
auto left = Parameter<String>(Descriptor::kLeft);
auto right = Parameter<String>(Descriptor::kRight);
GenerateStringRelationalComparison(left, right, Operation::kGreaterThan);
}
TF_BUILTIN(StringGreaterThanOrEqual, StringBuiltinsAssembler) {
auto left = Parameter<String>(Descriptor::kLeft);
auto right = Parameter<String>(Descriptor::kRight);
GenerateStringRelationalComparison(left, right,
Operation::kGreaterThanOrEqual);
}
TF_BUILTIN(StringCodePointAt, StringBuiltinsAssembler) {
auto receiver = Parameter<String>(Descriptor::kReceiver);
auto position = UncheckedParameter<IntPtrT>(Descriptor::kPosition);
// TODO(sigurds) Figure out if passing length as argument pays off.
TNode<IntPtrT> length = LoadStringLengthAsWord(receiver);
// Load the character code at the {position} from the {receiver}.
TNode<Int32T> code =
LoadSurrogatePairAt(receiver, length, position, UnicodeEncoding::UTF32);
// And return it as TaggedSigned value.
// TODO(turbofan): Allow builtins to return values untagged.
TNode<Smi> result = SmiFromInt32(code);
Return(result);
}
TF_BUILTIN(StringFromCodePointAt, StringBuiltinsAssembler) {
auto receiver = Parameter<String>(Descriptor::kReceiver);
auto position = UncheckedParameter<IntPtrT>(Descriptor::kPosition);
// TODO(sigurds) Figure out if passing length as argument pays off.
TNode<IntPtrT> length = LoadStringLengthAsWord(receiver);
// Load the character code at the {position} from the {receiver}.
TNode<Int32T> code =
LoadSurrogatePairAt(receiver, length, position, UnicodeEncoding::UTF16);
// Create a String from the UTF16 encoded code point
TNode<String> result = StringFromSingleUTF16EncodedCodePoint(code);
Return(result);
}
// -----------------------------------------------------------------------------
// ES6 section 21.1 String Objects
// ES6 #sec-string.fromcharcode
TF_BUILTIN(StringFromCharCode, StringBuiltinsAssembler) {
// TODO(ishell): use constants from Descriptor once the JSFunction linkage
// arguments are reordered.
auto argc = UncheckedParameter<Int32T>(Descriptor::kJSActualArgumentsCount);
auto context = Parameter<Context>(Descriptor::kContext);
CodeStubArguments arguments(this, argc);
// Check if we have exactly one argument (plus the implicit receiver), i.e.
// if the parent frame is not an arguments adaptor frame.
Label if_oneargument(this), if_notoneargument(this);
Branch(Word32Equal(argc, Int32Constant(1)), &if_oneargument,
&if_notoneargument);
BIND(&if_oneargument);
{
// Single argument case, perform fast single character string cache lookup
// for one-byte code units, or fall back to creating a single character
// string on the fly otherwise.
TNode<Object> code = arguments.AtIndex(0);
TNode<Word32T> code32 = TruncateTaggedToWord32(context, code);
TNode<Int32T> code16 =
Signed(Word32And(code32, Int32Constant(String::kMaxUtf16CodeUnit)));
TNode<String> result = StringFromSingleCharCode(code16);
arguments.PopAndReturn(result);
}
TNode<Word32T> code16;
BIND(&if_notoneargument);
{
Label two_byte(this);
// Assume that the resulting string contains only one-byte characters.
TNode<String> one_byte_result = AllocateSeqOneByteString(Unsigned(argc));
TVARIABLE(IntPtrT, var_max_index, IntPtrConstant(0));
// Iterate over the incoming arguments, converting them to 8-bit character
// codes. Stop if any of the conversions generates a code that doesn't fit
// in 8 bits.
CodeStubAssembler::VariableList vars({&var_max_index}, zone());
arguments.ForEach(vars, [&](TNode<Object> arg) {
TNode<Word32T> code32 = TruncateTaggedToWord32(context, arg);
code16 = Word32And(code32, Int32Constant(String::kMaxUtf16CodeUnit));
GotoIf(
Int32GreaterThan(code16, Int32Constant(String::kMaxOneByteCharCode)),
&two_byte);
// The {code16} fits into the SeqOneByteString {one_byte_result}.
TNode<IntPtrT> offset = ElementOffsetFromIndex(
var_max_index.value(), UINT8_ELEMENTS,
SeqOneByteString::kHeaderSize - kHeapObjectTag);
StoreNoWriteBarrier(MachineRepresentation::kWord8, one_byte_result,
offset, code16);
var_max_index = IntPtrAdd(var_max_index.value(), IntPtrConstant(1));
});
arguments.PopAndReturn(one_byte_result);
BIND(&two_byte);
// At least one of the characters in the string requires a 16-bit
// representation. Allocate a SeqTwoByteString to hold the resulting
// string.
TNode<String> two_byte_result = AllocateSeqTwoByteString(Unsigned(argc));
// Copy the characters that have already been put in the 8-bit string into
// their corresponding positions in the new 16-bit string.
TNode<IntPtrT> zero = IntPtrConstant(0);
CopyStringCharacters(one_byte_result, two_byte_result, zero, zero,
var_max_index.value(), String::ONE_BYTE_ENCODING,
String::TWO_BYTE_ENCODING);
// Write the character that caused the 8-bit to 16-bit fault.
TNode<IntPtrT> max_index_offset =
ElementOffsetFromIndex(var_max_index.value(), UINT16_ELEMENTS,
SeqTwoByteString::kHeaderSize - kHeapObjectTag);
StoreNoWriteBarrier(MachineRepresentation::kWord16, two_byte_result,
max_index_offset, code16);
var_max_index = IntPtrAdd(var_max_index.value(), IntPtrConstant(1));
// Resume copying the passed-in arguments from the same place where the
// 8-bit copy stopped, but this time copying over all of the characters
// using a 16-bit representation.
arguments.ForEach(
vars,
[&](TNode<Object> arg) {
TNode<Word32T> code32 = TruncateTaggedToWord32(context, arg);
TNode<Word32T> code16 =
Word32And(code32, Int32Constant(String::kMaxUtf16CodeUnit));
TNode<IntPtrT> offset = ElementOffsetFromIndex(
var_max_index.value(), UINT16_ELEMENTS,
SeqTwoByteString::kHeaderSize - kHeapObjectTag);
StoreNoWriteBarrier(MachineRepresentation::kWord16, two_byte_result,
offset, code16);
var_max_index = IntPtrAdd(var_max_index.value(), IntPtrConstant(1));
},
var_max_index.value());
arguments.PopAndReturn(two_byte_result);
}
}
void StringBuiltinsAssembler::StringIndexOf(
const TNode<String> subject_string, const TNode<String> search_string,
const TNode<Smi> position,
const std::function<void(TNode<Smi>)>& f_return) {
const TNode<IntPtrT> int_zero = IntPtrConstant(0);
const TNode<IntPtrT> search_length = LoadStringLengthAsWord(search_string);
const TNode<IntPtrT> subject_length = LoadStringLengthAsWord(subject_string);
const TNode<IntPtrT> start_position = IntPtrMax(SmiUntag(position), int_zero);
Label zero_length_needle(this), return_minus_1(this);
{
GotoIf(IntPtrEqual(int_zero, search_length), &zero_length_needle);
// Check that the needle fits in the start position.
GotoIfNot(IntPtrLessThanOrEqual(search_length,
IntPtrSub(subject_length, start_position)),
&return_minus_1);
}
// If the string pointers are identical, we can just return 0. Note that this
// implies {start_position} == 0 since we've passed the check above.
Label return_zero(this);
GotoIf(TaggedEqual(subject_string, search_string), &return_zero);
// Try to unpack subject and search strings. Bail to runtime if either needs
// to be flattened.
ToDirectStringAssembler subject_to_direct(state(), subject_string);
ToDirectStringAssembler search_to_direct(state(), search_string);
Label call_runtime_unchecked(this, Label::kDeferred);
subject_to_direct.TryToDirect(&call_runtime_unchecked);
search_to_direct.TryToDirect(&call_runtime_unchecked);
// Load pointers to string data.
const TNode<RawPtrT> subject_ptr =
subject_to_direct.PointerToData(&call_runtime_unchecked);
const TNode<RawPtrT> search_ptr =
search_to_direct.PointerToData(&call_runtime_unchecked);
const TNode<IntPtrT> subject_offset = subject_to_direct.offset();
const TNode<IntPtrT> search_offset = search_to_direct.offset();
// Like String::IndexOf, the actual matching is done by the optimized
// SearchString method in string-search.h. Dispatch based on string instance
// types, then call straight into C++ for matching.
CSA_ASSERT(this, IntPtrGreaterThan(search_length, int_zero));
CSA_ASSERT(this, IntPtrGreaterThanOrEqual(start_position, int_zero));
CSA_ASSERT(this, IntPtrGreaterThanOrEqual(subject_length, start_position));
CSA_ASSERT(this,
IntPtrLessThanOrEqual(search_length,
IntPtrSub(subject_length, start_position)));
Label one_one(this), one_two(this), two_one(this), two_two(this);
DispatchOnStringEncodings(subject_to_direct.instance_type(),
search_to_direct.instance_type(), &one_one,
&one_two, &two_one, &two_two);
using onebyte_t = const uint8_t;
using twobyte_t = const uc16;
BIND(&one_one);
{
const TNode<RawPtrT> adjusted_subject_ptr = PointerToStringDataAtIndex(
subject_ptr, subject_offset, String::ONE_BYTE_ENCODING);
const TNode<RawPtrT> adjusted_search_ptr = PointerToStringDataAtIndex(
search_ptr, search_offset, String::ONE_BYTE_ENCODING);
Label direct_memchr_call(this), generic_fast_path(this);
Branch(IntPtrEqual(search_length, IntPtrConstant(1)), &direct_memchr_call,
&generic_fast_path);
// An additional fast path that calls directly into memchr for 1-length
// search strings.
BIND(&direct_memchr_call);
{
const TNode<RawPtrT> string_addr =
RawPtrAdd(adjusted_subject_ptr, start_position);
const TNode<IntPtrT> search_length =
IntPtrSub(subject_length, start_position);
const TNode<IntPtrT> search_byte =
ChangeInt32ToIntPtr(Load<Uint8T>(adjusted_search_ptr));
const TNode<ExternalReference> memchr =
ExternalConstant(ExternalReference::libc_memchr_function());
const TNode<RawPtrT> result_address = UncheckedCast<RawPtrT>(
CallCFunction(memchr, MachineType::Pointer(),
std::make_pair(MachineType::Pointer(), string_addr),
std::make_pair(MachineType::IntPtr(), search_byte),
std::make_pair(MachineType::UintPtr(), search_length)));
GotoIf(WordEqual(result_address, int_zero), &return_minus_1);
const TNode<IntPtrT> result_index =
IntPtrAdd(RawPtrSub(result_address, string_addr), start_position);
f_return(SmiTag(result_index));
}
BIND(&generic_fast_path);
{
const TNode<IntPtrT> result = CallSearchStringRaw<onebyte_t, onebyte_t>(
adjusted_subject_ptr, subject_length, adjusted_search_ptr,
search_length, start_position);
f_return(SmiTag(result));
}
}
BIND(&one_two);
{
const TNode<RawPtrT> adjusted_subject_ptr = PointerToStringDataAtIndex(
subject_ptr, subject_offset, String::ONE_BYTE_ENCODING);
const TNode<RawPtrT> adjusted_search_ptr = PointerToStringDataAtIndex(
search_ptr, search_offset, String::TWO_BYTE_ENCODING);
const TNode<IntPtrT> result = CallSearchStringRaw<onebyte_t, twobyte_t>(
adjusted_subject_ptr, subject_length, adjusted_search_ptr,
search_length, start_position);
f_return(SmiTag(result));
}
BIND(&two_one);
{
const TNode<RawPtrT> adjusted_subject_ptr = PointerToStringDataAtIndex(
subject_ptr, subject_offset, String::TWO_BYTE_ENCODING);
const TNode<RawPtrT> adjusted_search_ptr = PointerToStringDataAtIndex(
search_ptr, search_offset, String::ONE_BYTE_ENCODING);
const TNode<IntPtrT> result = CallSearchStringRaw<twobyte_t, onebyte_t>(
adjusted_subject_ptr, subject_length, adjusted_search_ptr,
search_length, start_position);
f_return(SmiTag(result));
}
BIND(&two_two);
{
const TNode<RawPtrT> adjusted_subject_ptr = PointerToStringDataAtIndex(
subject_ptr, subject_offset, String::TWO_BYTE_ENCODING);
const TNode<RawPtrT> adjusted_search_ptr = PointerToStringDataAtIndex(
search_ptr, search_offset, String::TWO_BYTE_ENCODING);
const TNode<IntPtrT> result = CallSearchStringRaw<twobyte_t, twobyte_t>(
adjusted_subject_ptr, subject_length, adjusted_search_ptr,
search_length, start_position);
f_return(SmiTag(result));
}
BIND(&return_minus_1);
f_return(SmiConstant(-1));
BIND(&return_zero);
f_return(SmiConstant(0));
BIND(&zero_length_needle);
{
Comment("0-length search_string");
f_return(SmiTag(IntPtrMin(subject_length, start_position)));
}
BIND(&call_runtime_unchecked);
{
// Simplified version of the runtime call where the types of the arguments
// are already known due to type checks in this stub.
Comment("Call Runtime Unchecked");
TNode<Smi> result =
CAST(CallRuntime(Runtime::kStringIndexOfUnchecked, NoContextConstant(),
subject_string, search_string, position));
f_return(result);
}
}
// ES6 String.prototype.indexOf(searchString [, position])
// #sec-string.prototype.indexof
// Unchecked helper for builtins lowering.
TF_BUILTIN(StringIndexOf, StringBuiltinsAssembler) {
auto receiver = Parameter<String>(Descriptor::kReceiver);
auto search_string = Parameter<String>(Descriptor::kSearchString);
auto position = Parameter<Smi>(Descriptor::kPosition);
StringIndexOf(receiver, search_string, position,
[this](TNode<Smi> result) { this->Return(result); });
}
// ES6 String.prototype.includes(searchString [, position])
// #sec-string.prototype.includes
TF_BUILTIN(StringPrototypeIncludes, StringIncludesIndexOfAssembler) {
TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
UncheckedParameter<Int32T>(Descriptor::kJSActualArgumentsCount));
auto context = Parameter<Context>(Descriptor::kContext);
Generate(kIncludes, argc, context);
}
// ES6 String.prototype.indexOf(searchString [, position])
// #sec-string.prototype.indexof
TF_BUILTIN(StringPrototypeIndexOf, StringIncludesIndexOfAssembler) {
TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
UncheckedParameter<Int32T>(Descriptor::kJSActualArgumentsCount));
auto context = Parameter<Context>(Descriptor::kContext);
Generate(kIndexOf, argc, context);
}
void StringIncludesIndexOfAssembler::Generate(SearchVariant variant,
TNode<IntPtrT> argc,
TNode<Context> context) {
CodeStubArguments arguments(this, argc);
const TNode<Object> receiver = arguments.GetReceiver();
TVARIABLE(Object, var_search_string);
TVARIABLE(Object, var_position);
Label argc_1(this), argc_2(this), call_runtime(this, Label::kDeferred),
fast_path(this);
GotoIf(IntPtrEqual(argc, IntPtrConstant(1)), &argc_1);
GotoIf(IntPtrGreaterThan(argc, IntPtrConstant(1)), &argc_2);
{
Comment("0 Argument case");
CSA_ASSERT(this, IntPtrEqual(argc, IntPtrConstant(0)));
TNode<Oddball> undefined = UndefinedConstant();
var_search_string = undefined;
var_position = undefined;
Goto(&call_runtime);
}
BIND(&argc_1);
{
Comment("1 Argument case");
var_search_string = arguments.AtIndex(0);
var_position = SmiConstant(0);
Goto(&fast_path);
}
BIND(&argc_2);
{
Comment("2 Argument case");
var_search_string = arguments.AtIndex(0);
var_position = arguments.AtIndex(1);
GotoIfNot(TaggedIsSmi(var_position.value()), &call_runtime);
Goto(&fast_path);
}
BIND(&fast_path);
{
Comment("Fast Path");
const TNode<Object> search = var_search_string.value();
const TNode<Smi> position = CAST(var_position.value());
GotoIf(TaggedIsSmi(receiver), &call_runtime);
GotoIf(TaggedIsSmi(search), &call_runtime);
GotoIfNot(IsString(CAST(receiver)), &call_runtime);
GotoIfNot(IsString(CAST(search)), &call_runtime);
StringIndexOf(CAST(receiver), CAST(search), position,
[&](TNode<Smi> result) {
if (variant == kIndexOf) {
arguments.PopAndReturn(result);
} else {
arguments.PopAndReturn(SelectBooleanConstant(
SmiGreaterThanOrEqual(result, SmiConstant(0))));
}
});
}
BIND(&call_runtime);
{
Comment("Call Runtime");
Runtime::FunctionId runtime = variant == kIndexOf
? Runtime::kStringIndexOf
: Runtime::kStringIncludes;
const TNode<Object> result =
CallRuntime(runtime, context, receiver, var_search_string.value(),
var_position.value());
arguments.PopAndReturn(result);
}
}
void StringBuiltinsAssembler::MaybeCallFunctionAtSymbol(
const TNode<Context> context, const TNode<Object> object,
const TNode<Object> maybe_string, Handle<Symbol> symbol,
DescriptorIndexNameValue additional_property_to_check,
const NodeFunction0& regexp_call, const NodeFunction1& generic_call) {
Label out(this);
Label get_property_lookup(this);
// Smis have to go through the GetProperty lookup in case Number.prototype or
// Object.prototype was modified.
GotoIf(TaggedIsSmi(object), &get_property_lookup);
// Take the fast path for RegExps.
// There's two conditions: {object} needs to be a fast regexp, and
// {maybe_string} must be a string (we can't call ToString on the fast path
// since it may mutate {object}).
{
Label stub_call(this), slow_lookup(this);
TNode<HeapObject> heap_object = CAST(object);
GotoIf(TaggedIsSmi(maybe_string), &slow_lookup);
GotoIfNot(IsString(CAST(maybe_string)), &slow_lookup);
// Note we don't run a full (= permissive) check here, because passing the
// check implies calling the fast variants of target builtins, which assume
// we've already made their appropriate fast path checks. This is not the
// case though; e.g.: some of the target builtins access flag getters.
// TODO(jgruber): Handle slow flag accesses on the fast path and make this
// permissive.
RegExpBuiltinsAssembler regexp_asm(state());
regexp_asm.BranchIfFastRegExp(
context, heap_object, LoadMap(heap_object),
PrototypeCheckAssembler::kCheckPrototypePropertyConstness,
additional_property_to_check, &stub_call, &slow_lookup);
BIND(&stub_call);
// TODO(jgruber): Add a no-JS scope once it exists.
regexp_call();
BIND(&slow_lookup);
// Special case null and undefined to skip the property lookup.
Branch(IsNullOrUndefined(heap_object), &out, &get_property_lookup);
}
// Fall back to a slow lookup of {heap_object[symbol]}.
//
// The spec uses GetMethod({heap_object}, {symbol}), which has a few quirks:
// * null values are turned into undefined, and
// * an exception is thrown if the value is not undefined, null, or callable.
// We handle the former by jumping to {out} for null values as well, while
// the latter is already handled by the Call({maybe_func}) operation.
BIND(&get_property_lookup);
const TNode<Object> maybe_func = GetProperty(context, object, symbol);
GotoIf(IsUndefined(maybe_func), &out);
GotoIf(IsNull(maybe_func), &out);
// Attempt to call the function.
generic_call(maybe_func);
BIND(&out);
}
const TNode<Smi> StringBuiltinsAssembler::IndexOfDollarChar(
const TNode<Context> context, const TNode<String> string) {
const TNode<String> dollar_string = HeapConstant(
isolate()->factory()->LookupSingleCharacterStringFromCode('$'));
const TNode<Smi> dollar_ix =
CAST(CallBuiltin(Builtins::kStringIndexOf, context, string, dollar_string,
SmiConstant(0)));
return dollar_ix;
}
TNode<String> StringBuiltinsAssembler::GetSubstitution(
TNode<Context> context, TNode<String> subject_string,
TNode<Smi> match_start_index, TNode<Smi> match_end_index,
TNode<String> replace_string) {
CSA_ASSERT(this, TaggedIsPositiveSmi(match_start_index));
CSA_ASSERT(this, TaggedIsPositiveSmi(match_end_index));
TVARIABLE(String, var_result, replace_string);
Label runtime(this), out(this);
// In this primitive implementation we simply look for the next '$' char in
// {replace_string}. If it doesn't exist, we can simply return
// {replace_string} itself. If it does, then we delegate to
// String::GetSubstitution, passing in the index of the first '$' to avoid
// repeated scanning work.
// TODO(jgruber): Possibly extend this in the future to handle more complex
// cases without runtime calls.
const TNode<Smi> dollar_index = IndexOfDollarChar(context, replace_string);
Branch(SmiIsNegative(dollar_index), &out, &runtime);
BIND(&runtime);
{
CSA_ASSERT(this, TaggedIsPositiveSmi(dollar_index));
const TNode<Object> matched =
CallBuiltin(Builtins::kStringSubstring, context, subject_string,
SmiUntag(match_start_index), SmiUntag(match_end_index));
const TNode<String> replacement_string = CAST(
CallRuntime(Runtime::kGetSubstitution, context, matched, subject_string,
match_start_index, replace_string, dollar_index));
var_result = replacement_string;
Goto(&out);
}
BIND(&out);
return var_result.value();
}
// ES6 #sec-string.prototype.replace
TF_BUILTIN(StringPrototypeReplace, StringBuiltinsAssembler) {
Label out(this);
auto receiver = Parameter<Object>(Descriptor::kReceiver);
const auto search = Parameter<Object>(Descriptor::kSearch);
const auto replace = Parameter<Object>(Descriptor::kReplace);
auto context = Parameter<Context>(Descriptor::kContext);
const TNode<Smi> smi_zero = SmiConstant(0);
RequireObjectCoercible(context, receiver, "String.prototype.replace");
// Redirect to replacer method if {search[@@replace]} is not undefined.
MaybeCallFunctionAtSymbol(
context, search, receiver, isolate()->factory()->replace_symbol(),
DescriptorIndexNameValue{JSRegExp::kSymbolReplaceFunctionDescriptorIndex,
RootIndex::kreplace_symbol,
Context::REGEXP_REPLACE_FUNCTION_INDEX},
[=]() {
Return(CallBuiltin(Builtins::kRegExpReplace, context, search, receiver,
replace));
},
[=](TNode<Object> fn) {
Return(Call(context, fn, search, receiver, replace));
});
// Convert {receiver} and {search} to strings.
const TNode<String> subject_string = ToString_Inline(context, receiver);
const TNode<String> search_string = ToString_Inline(context, search);
const TNode<IntPtrT> subject_length = LoadStringLengthAsWord(subject_string);
const TNode<IntPtrT> search_length = LoadStringLengthAsWord(search_string);
// Fast-path single-char {search}, long cons {receiver}, and simple string
// {replace}.
{
Label next(this);
GotoIfNot(WordEqual(search_length, IntPtrConstant(1)), &next);
GotoIfNot(IntPtrGreaterThan(subject_length, IntPtrConstant(0xFF)), &next);
GotoIf(TaggedIsSmi(replace), &next);
GotoIfNot(IsString(CAST(replace)), &next);
TNode<String> replace_string = CAST(replace);
const TNode<Uint16T> subject_instance_type =
LoadInstanceType(subject_string);
GotoIfNot(IsConsStringInstanceType(subject_instance_type), &next);
GotoIf(TaggedIsPositiveSmi(IndexOfDollarChar(context, replace_string)),
&next);
// Searching by traversing a cons string tree and replace with cons of
// slices works only when the replaced string is a single character, being
// replaced by a simple string and only pays off for long strings.
// TODO(jgruber): Reevaluate if this is still beneficial.
// TODO(jgruber): TailCallRuntime when it correctly handles adapter frames.
Return(CallRuntime(Runtime::kStringReplaceOneCharWithString, context,
subject_string, search_string, replace_string));
BIND(&next);
}
// TODO(jgruber): Extend StringIndexOf to handle two-byte strings and
// longer substrings - we can handle up to 8 chars (one-byte) / 4 chars
// (2-byte).
const TNode<Smi> match_start_index =
CAST(CallBuiltin(Builtins::kStringIndexOf, context, subject_string,
search_string, smi_zero));
// Early exit if no match found.
{
Label next(this), return_subject(this);
GotoIfNot(SmiIsNegative(match_start_index), &next);
// The spec requires to perform ToString(replace) if the {replace} is not
// callable even if we are going to exit here.
// Since ToString() being applied to Smi does not have side effects for
// numbers we can skip it.
GotoIf(TaggedIsSmi(replace), &return_subject);
GotoIf(IsCallableMap(LoadMap(CAST(replace))), &return_subject);
// TODO(jgruber): Could introduce ToStringSideeffectsStub which only
// performs observable parts of ToString.
ToString_Inline(context, replace);
Goto(&return_subject);
BIND(&return_subject);
Return(subject_string);
BIND(&next);
}
const TNode<Smi> match_end_index =
SmiAdd(match_start_index, SmiFromIntPtr(search_length));
TVARIABLE(String, var_result, EmptyStringConstant());
// Compute the prefix.
{
Label next(this);
GotoIf(SmiEqual(match_start_index, smi_zero), &next);
const TNode<String> prefix =
CAST(CallBuiltin(Builtins::kStringSubstring, context, subject_string,
IntPtrConstant(0), SmiUntag(match_start_index)));
var_result = prefix;
Goto(&next);
BIND(&next);
}
// Compute the string to replace with.
Label if_iscallablereplace(this), if_notcallablereplace(this);
GotoIf(TaggedIsSmi(replace), &if_notcallablereplace);
Branch(IsCallableMap(LoadMap(CAST(replace))), &if_iscallablereplace,
&if_notcallablereplace);
BIND(&if_iscallablereplace);
{
const TNode<Object> replacement =
Call(context, replace, UndefinedConstant(), search_string,
match_start_index, subject_string);
const TNode<String> replacement_string =
ToString_Inline(context, replacement);
var_result = CAST(CallBuiltin(Builtins::kStringAdd_CheckNone, context,
var_result.value(), replacement_string));
Goto(&out);
}
BIND(&if_notcallablereplace);
{
const TNode<String> replace_string = ToString_Inline(context, replace);
const TNode<Object> replacement =
GetSubstitution(context, subject_string, match_start_index,
match_end_index, replace_string);
var_result = CAST(CallBuiltin(Builtins::kStringAdd_CheckNone, context,
var_result.value(), replacement));
Goto(&out);
}
BIND(&out);
{
const TNode<Object> suffix =
CallBuiltin(Builtins::kStringSubstring, context, subject_string,
SmiUntag(match_end_index), subject_length);
const TNode<Object> result = CallBuiltin(
Builtins::kStringAdd_CheckNone, context, var_result.value(), suffix);
Return(result);
}
}
class StringMatchSearchAssembler : public StringBuiltinsAssembler {
public:
explicit StringMatchSearchAssembler(compiler::CodeAssemblerState* state)
: StringBuiltinsAssembler(state) {}
protected:
enum Variant { kMatch, kSearch };
void Generate(Variant variant, const char* method_name,
TNode<Object> receiver, TNode<Object> maybe_regexp,
TNode<Context> context) {
Label call_regexp_match_search(this);
Builtins::Name builtin;
Handle<Symbol> symbol;
DescriptorIndexNameValue property_to_check;
if (variant == kMatch) {
builtin = Builtins::kRegExpMatchFast;
symbol = isolate()->factory()->match_symbol();
property_to_check = DescriptorIndexNameValue{
JSRegExp::kSymbolMatchFunctionDescriptorIndex,
RootIndex::kmatch_symbol, Context::REGEXP_MATCH_FUNCTION_INDEX};
} else {
builtin = Builtins::kRegExpSearchFast;
symbol = isolate()->factory()->search_symbol();
property_to_check = DescriptorIndexNameValue{
JSRegExp::kSymbolSearchFunctionDescriptorIndex,
RootIndex::ksearch_symbol, Context::REGEXP_SEARCH_FUNCTION_INDEX};
}
RequireObjectCoercible(context, receiver, method_name);
MaybeCallFunctionAtSymbol(
context, maybe_regexp, receiver, symbol, property_to_check,
[=] { Return(CallBuiltin(builtin, context, maybe_regexp, receiver)); },
[=](TNode<Object> fn) {
Return(Call(context, fn, maybe_regexp, receiver));
});
// maybe_regexp is not a RegExp nor has [@@match / @@search] property.
{
RegExpBuiltinsAssembler regexp_asm(state());
TNode<String> receiver_string = ToString_Inline(context, receiver);
TNode<NativeContext> native_context = LoadNativeContext(context);
TNode<HeapObject> regexp_function = CAST(
LoadContextElement(native_context, Context::REGEXP_FUNCTION_INDEX));
TNode<Map> initial_map = CAST(LoadObjectField(
regexp_function, JSFunction::kPrototypeOrInitialMapOffset));
TNode<Object> regexp = regexp_asm.RegExpCreate(
context, initial_map, maybe_regexp, EmptyStringConstant());
// TODO(jgruber): Handle slow flag accesses on the fast path and make this
// permissive.
Label fast_path(this), slow_path(this);
regexp_asm.BranchIfFastRegExp(
context, CAST(regexp), initial_map,
PrototypeCheckAssembler::kCheckPrototypePropertyConstness,
property_to_check, &fast_path, &slow_path);
BIND(&fast_path);
Return(CallBuiltin(builtin, context, regexp, receiver_string));
BIND(&slow_path);
{
TNode<Object> maybe_func = GetProperty(context, regexp, symbol);
Return(Call(context, maybe_func, regexp, receiver_string));
}
}
}
};
// ES6 #sec-string.prototype.match
TF_BUILTIN(StringPrototypeMatch, StringMatchSearchAssembler) {
auto receiver = Parameter<Object>(Descriptor::kReceiver);
auto maybe_regexp = Parameter<Object>(Descriptor::kRegexp);
auto context = Parameter<Context>(Descriptor::kContext);
Generate(kMatch, "String.prototype.match", receiver, maybe_regexp, context);
}
// ES #sec-string.prototype.matchAll
TF_BUILTIN(StringPrototypeMatchAll, StringBuiltinsAssembler) {
char const* method_name = "String.prototype.matchAll";
auto context = Parameter<Context>(Descriptor::kContext);
auto maybe_regexp = Parameter<Object>(Descriptor::kRegexp);
auto receiver = Parameter<Object>(Descriptor::kReceiver);
TNode<NativeContext> native_context = LoadNativeContext(context);
// 1. Let O be ? RequireObjectCoercible(this value).
RequireObjectCoercible(context, receiver, method_name);
RegExpMatchAllAssembler regexp_asm(state());
{
Label fast(this), slow(this, Label::kDeferred),
throw_exception(this, Label::kDeferred),
throw_flags_exception(this, Label::kDeferred), next(this);
// 2. If regexp is neither undefined nor null, then
// a. Let isRegExp be ? IsRegExp(regexp).
// b. If isRegExp is true, then
// i. Let flags be ? Get(regexp, "flags").
// ii. Perform ? RequireObjectCoercible(flags).
// iii. If ? ToString(flags) does not contain "g", throw a
// TypeError exception.
GotoIf(TaggedIsSmi(maybe_regexp), &next);
TNode<HeapObject> heap_maybe_regexp = CAST(maybe_regexp);
regexp_asm.BranchIfFastRegExp_Strict(context, heap_maybe_regexp, &fast,
&slow);
BIND(&fast);
{
TNode<BoolT> is_global = regexp_asm.FlagGetter(context, heap_maybe_regexp,
JSRegExp::kGlobal, true);
Branch(is_global, &next, &throw_exception);
}
BIND(&slow);
{
GotoIfNot(regexp_asm.IsRegExp(native_context, heap_maybe_regexp), &next);
TNode<Object> flags = GetProperty(context, heap_maybe_regexp,
isolate()->factory()->flags_string());
// TODO(syg): Implement a RequireObjectCoercible with more flexible error
// messages.
GotoIf(IsNullOrUndefined(flags), &throw_flags_exception);
TNode<String> flags_string = ToString_Inline(context, flags);
TNode<String> global_char_string = StringConstant("g");
TNode<Smi> global_ix =
CAST(CallBuiltin(Builtins::kStringIndexOf, context, flags_string,
global_char_string, SmiConstant(0)));
Branch(SmiEqual(global_ix, SmiConstant(-1)), &throw_exception, &next);
}
BIND(&throw_exception);
ThrowTypeError(context, MessageTemplate::kRegExpGlobalInvokedOnNonGlobal,
method_name);
BIND(&throw_flags_exception);
ThrowTypeError(context,
MessageTemplate::kStringMatchAllNullOrUndefinedFlags);
BIND(&next);
}
// a. Let matcher be ? GetMethod(regexp, @@matchAll).
// b. If matcher is not undefined, then
// i. Return ? Call(matcher, regexp, « O »).
auto if_regexp_call = [&] {
// MaybeCallFunctionAtSymbol guarantees fast path is chosen only if
// maybe_regexp is a fast regexp and receiver is a string.
TNode<String> s = CAST(receiver);
Return(
RegExpPrototypeMatchAllImpl(context, native_context, maybe_regexp, s));
};
auto if_generic_call = [=](TNode<Object> fn) {
Return(Call(context, fn, maybe_regexp, receiver));
};
MaybeCallFunctionAtSymbol(
context, maybe_regexp, receiver, isolate()->factory()->match_all_symbol(),
DescriptorIndexNameValue{JSRegExp::kSymbolMatchAllFunctionDescriptorIndex,
RootIndex::kmatch_all_symbol,
Context::REGEXP_MATCH_ALL_FUNCTION_INDEX},
if_regexp_call, if_generic_call);
// 3. Let S be ? ToString(O).
TNode<String> s = ToString_Inline(context, receiver);
// 4. Let rx be ? RegExpCreate(R, "g").
TNode<Object> rx = regexp_asm.RegExpCreate(context, native_context,
maybe_regexp, StringConstant("g"));
// 5. Return ? Invoke(rx, @@matchAll, « S »).
TNode<Object> match_all_func =
GetProperty(context, rx, isolate()->factory()->match_all_symbol());
Return(Call(context, match_all_func, rx, s));
}
// ES6 #sec-string.prototype.search
TF_BUILTIN(StringPrototypeSearch, StringMatchSearchAssembler) {
auto receiver = Parameter<Object>(Descriptor::kReceiver);
auto maybe_regexp = Parameter<Object>(Descriptor::kRegexp);
auto context = Parameter<Context>(Descriptor::kContext);
Generate(kSearch, "String.prototype.search", receiver, maybe_regexp, context);
}
TNode<JSArray> StringBuiltinsAssembler::StringToArray(
TNode<NativeContext> context, TNode<String> subject_string,
TNode<Smi> subject_length, TNode<Number> limit_number) {
CSA_ASSERT(this, SmiGreaterThan(subject_length, SmiConstant(0)));
Label done(this), call_runtime(this, Label::kDeferred),
fill_thehole_and_call_runtime(this, Label::kDeferred);
TVARIABLE(JSArray, result_array);
TNode<Uint16T> instance_type = LoadInstanceType(subject_string);
GotoIfNot(IsOneByteStringInstanceType(instance_type), &call_runtime);
// Try to use cached one byte characters.
{
TNode<Smi> length_smi =
Select<Smi>(TaggedIsSmi(limit_number),
[=] { return SmiMin(CAST(limit_number), subject_length); },
[=] { return subject_length; });
TNode<IntPtrT> length = SmiToIntPtr(length_smi);
ToDirectStringAssembler to_direct(state(), subject_string);
to_direct.TryToDirect(&call_runtime);
// The extracted direct string may be two-byte even though the wrapping
// string is one-byte.
GotoIfNot(IsOneByteStringInstanceType(to_direct.instance_type()),
&call_runtime);
TNode<FixedArray> elements = CAST(AllocateFixedArray(
PACKED_ELEMENTS, length, AllocationFlag::kAllowLargeObjectAllocation));
// Don't allocate anything while {string_data} is live!
TNode<RawPtrT> string_data =
to_direct.PointerToData(&fill_thehole_and_call_runtime);
TNode<IntPtrT> string_data_offset = to_direct.offset();
TNode<FixedArray> cache = SingleCharacterStringCacheConstant();
BuildFastLoop<IntPtrT>(
IntPtrConstant(0), length,
[&](TNode<IntPtrT> index) {
// TODO(jkummerow): Implement a CSA version of DisallowHeapAllocation
// and use that to guard ToDirectStringAssembler.PointerToData().
CSA_ASSERT(this, WordEqual(to_direct.PointerToData(&call_runtime),
string_data));
TNode<Int32T> char_code =
UncheckedCast<Int32T>(Load(MachineType::Uint8(), string_data,
IntPtrAdd(index, string_data_offset)));
TNode<UintPtrT> code_index = ChangeUint32ToWord(char_code);
TNode<Object> entry = LoadFixedArrayElement(cache, code_index);
// If we cannot find a char in the cache, fill the hole for the fixed
// array, and call runtime.
GotoIf(IsUndefined(entry), &fill_thehole_and_call_runtime);
StoreFixedArrayElement(elements, index, entry);
},
1, IndexAdvanceMode::kPost);
TNode<Map> array_map = LoadJSArrayElementsMap(PACKED_ELEMENTS, context);
result_array = AllocateJSArray(array_map, elements, length_smi);
Goto(&done);
BIND(&fill_thehole_and_call_runtime);
{
FillFixedArrayWithValue(PACKED_ELEMENTS, elements, IntPtrConstant(0),
length, RootIndex::kTheHoleValue);
Goto(&call_runtime);
}
}
BIND(&call_runtime);
{
result_array = CAST(CallRuntime(Runtime::kStringToArray, context,
subject_string, limit_number));
Goto(&done);
}
BIND(&done);
return result_array.value();
}
// ES6 section 21.1.3.19 String.prototype.split ( separator, limit )
TF_BUILTIN(StringPrototypeSplit, StringBuiltinsAssembler) {
const int kSeparatorArg = 0;
const int kLimitArg = 1;
const TNode<IntPtrT> argc = ChangeInt32ToIntPtr(
UncheckedParameter<Int32T>(Descriptor::kJSActualArgumentsCount));
CodeStubArguments args(this, argc);
TNode<Object> receiver = args.GetReceiver();
const TNode<Object> separator = args.GetOptionalArgumentValue(kSeparatorArg);
const TNode<Object> limit = args.GetOptionalArgumentValue(kLimitArg);
auto context = Parameter<NativeContext>(Descriptor::kContext);
TNode<Smi> smi_zero = SmiConstant(0);
RequireObjectCoercible(context, receiver, "String.prototype.split");
// Redirect to splitter method if {separator[@@split]} is not undefined.
MaybeCallFunctionAtSymbol(
context, separator, receiver, isolate()->factory()->split_symbol(),
DescriptorIndexNameValue{JSRegExp::kSymbolSplitFunctionDescriptorIndex,
RootIndex::ksplit_symbol,
Context::REGEXP_SPLIT_FUNCTION_INDEX},
[&]() {
args.PopAndReturn(CallBuiltin(Builtins::kRegExpSplit, context,
separator, receiver, limit));
},
[&](TNode<Object> fn) {
args.PopAndReturn(Call(context, fn, separator, receiver, limit));
});
// String and integer conversions.
TNode<String> subject_string = ToString_Inline(context, receiver);
TNode<Number> limit_number = Select<Number>(
IsUndefined(limit), [=] { return NumberConstant(kMaxUInt32); },
[=] { return ToUint32(context, limit); });
const TNode<String> separator_string = ToString_Inline(context, separator);
Label return_empty_array(this);
// Shortcut for {limit} == 0.
GotoIf(TaggedEqual(limit_number, smi_zero), &return_empty_array);
// ECMA-262 says that if {separator} is undefined, the result should
// be an array of size 1 containing the entire string.
{
Label next(this);
GotoIfNot(IsUndefined(separator), &next);
const ElementsKind kind = PACKED_ELEMENTS;
const TNode<NativeContext> native_context = LoadNativeContext(context);
TNode<Map> array_map = LoadJSArrayElementsMap(kind, native_context);
TNode<Smi> length = SmiConstant(1);
TNode<IntPtrT> capacity = IntPtrConstant(1);
TNode<JSArray> result = AllocateJSArray(kind, array_map, capacity, length);
TNode<FixedArray> fixed_array = CAST(LoadElements(result));
StoreFixedArrayElement(fixed_array, 0, subject_string);
args.PopAndReturn(result);
BIND(&next);
}
// If the separator string is empty then return the elements in the subject.
{
Label next(this);
GotoIfNot(SmiEqual(LoadStringLengthAsSmi(separator_string), smi_zero),
&next);
TNode<Smi> subject_length = LoadStringLengthAsSmi(subject_string);
GotoIf(SmiEqual(subject_length, smi_zero), &return_empty_array);
args.PopAndReturn(
StringToArray(context, subject_string, subject_length, limit_number));
BIND(&next);
}
const TNode<Object> result =
CallRuntime(Runtime::kStringSplit, context, subject_string,
separator_string, limit_number);
args.PopAndReturn(result);
BIND(&return_empty_array);
{
const ElementsKind kind = PACKED_ELEMENTS;
const TNode<NativeContext> native_context = LoadNativeContext(context);
TNode<Map> array_map = LoadJSArrayElementsMap(kind, native_context);
TNode<Smi> length = smi_zero;
TNode<IntPtrT> capacity = IntPtrConstant(0);
TNode<JSArray> result = AllocateJSArray(kind, array_map, capacity, length);
args.PopAndReturn(result);
}
}
TF_BUILTIN(StringSubstring, StringBuiltinsAssembler) {
auto string = Parameter<String>(Descriptor::kString);
auto from = UncheckedParameter<IntPtrT>(Descriptor::kFrom);
auto to = UncheckedParameter<IntPtrT>(Descriptor::kTo);
Return(SubString(string, from, to));
}
// Return the |word32| codepoint at {index}. Supports SeqStrings and
// ExternalStrings.
// TODO(v8:9880): Use UintPtrT here.
TNode<Int32T> StringBuiltinsAssembler::LoadSurrogatePairAt(
TNode<String> string, TNode<IntPtrT> length, TNode<IntPtrT> index,
UnicodeEncoding encoding) {
Label handle_surrogate_pair(this), return_result(this);
TVARIABLE(Int32T, var_result);
TVARIABLE(Int32T, var_trail);
var_result = StringCharCodeAt(string, Unsigned(index));
var_trail = Int32Constant(0);
GotoIf(Word32NotEqual(Word32And(var_result.value(), Int32Constant(0xFC00)),
Int32Constant(0xD800)),
&return_result);
TNode<IntPtrT> next_index = IntPtrAdd(index, IntPtrConstant(1));
GotoIfNot(IntPtrLessThan(next_index, length), &return_result);
var_trail = StringCharCodeAt(string, Unsigned(next_index));
Branch(Word32Equal(Word32And(var_trail.value(), Int32Constant(0xFC00)),
Int32Constant(0xDC00)),
&handle_surrogate_pair, &return_result);
BIND(&handle_surrogate_pair);
{
TNode<Int32T> lead = var_result.value();
TNode<Int32T> trail = var_trail.value();
// Check that this path is only taken if a surrogate pair is found
CSA_SLOW_ASSERT(this,
Uint32GreaterThanOrEqual(lead, Int32Constant(0xD800)));
CSA_SLOW_ASSERT(this, Uint32LessThan(lead, Int32Constant(0xDC00)));
CSA_SLOW_ASSERT(this,
Uint32GreaterThanOrEqual(trail, Int32Constant(0xDC00)));
CSA_SLOW_ASSERT(this, Uint32LessThan(trail, Int32Constant(0xE000)));
switch (encoding) {
case UnicodeEncoding::UTF16:
var_result = Word32Or(
// Need to swap the order for big-endian platforms
#if V8_TARGET_BIG_ENDIAN
Word32Shl(lead, Int32Constant(16)), trail);
#else
Word32Shl(trail, Int32Constant(16)), lead);
#endif
break;
case UnicodeEncoding::UTF32: {
// Convert UTF16 surrogate pair into |word32| code point, encoded as
// UTF32.
TNode<Int32T> surrogate_offset =
Int32Constant(0x10000 - (0xD800 << 10) - 0xDC00);
// (lead << 10) + trail + SURROGATE_OFFSET
var_result = Int32Add(Word32Shl(lead, Int32Constant(10)),
Int32Add(trail, surrogate_offset));
break;
}
}
Goto(&return_result);
}
BIND(&return_result);
return var_result.value();
}
void StringBuiltinsAssembler::BranchIfStringPrimitiveWithNoCustomIteration(
TNode<Object> object, TNode<Context> context, Label* if_true,
Label* if_false) {
GotoIf(TaggedIsSmi(object), if_false);
GotoIfNot(IsString(CAST(object)), if_false);
// Check that the String iterator hasn't been modified in a way that would
// affect iteration.
TNode<PropertyCell> protector_cell = StringIteratorProtectorConstant();
DCHECK(isolate()->heap()->string_iterator_protector().IsPropertyCell());
Branch(
TaggedEqual(LoadObjectField(protector_cell, PropertyCell::kValueOffset),
SmiConstant(Protectors::kProtectorValid)),
if_true, if_false);
}
// Instantiate template due to shared library requirements.
template V8_EXPORT_PRIVATE void StringBuiltinsAssembler::CopyStringCharacters(
TNode<String> from_string, TNode<String> to_string,
TNode<IntPtrT> from_index, TNode<IntPtrT> to_index,
TNode<IntPtrT> character_count, String::Encoding from_encoding,
String::Encoding to_encoding);
template V8_EXPORT_PRIVATE void StringBuiltinsAssembler::CopyStringCharacters(
TNode<RawPtrT> from_string, TNode<String> to_string,
TNode<IntPtrT> from_index, TNode<IntPtrT> to_index,
TNode<IntPtrT> character_count, String::Encoding from_encoding,
String::Encoding to_encoding);
template <typename T>
void StringBuiltinsAssembler::CopyStringCharacters(
TNode<T> from_string, TNode<String> to_string, TNode<IntPtrT> from_index,
TNode<IntPtrT> to_index, TNode<IntPtrT> character_count,
String::Encoding from_encoding, String::Encoding to_encoding) {
// from_string could be either a String or a RawPtrT in the case we pass in
// faked sequential strings when handling external subject strings.
bool from_one_byte = from_encoding == String::ONE_BYTE_ENCODING;
bool to_one_byte = to_encoding == String::ONE_BYTE_ENCODING;
DCHECK_IMPLIES(to_one_byte, from_one_byte);
Comment("CopyStringCharacters ",
from_one_byte ? "ONE_BYTE_ENCODING" : "TWO_BYTE_ENCODING", " -> ",
to_one_byte ? "ONE_BYTE_ENCODING" : "TWO_BYTE_ENCODING");
ElementsKind from_kind = from_one_byte ? UINT8_ELEMENTS : UINT16_ELEMENTS;
ElementsKind to_kind = to_one_byte ? UINT8_ELEMENTS : UINT16_ELEMENTS;
STATIC_ASSERT(SeqOneByteString::kHeaderSize == SeqTwoByteString::kHeaderSize);
int header_size = SeqOneByteString::kHeaderSize - kHeapObjectTag;
TNode<IntPtrT> from_offset =
ElementOffsetFromIndex(from_index, from_kind, header_size);
TNode<IntPtrT> to_offset =
ElementOffsetFromIndex(to_index, to_kind, header_size);
TNode<IntPtrT> byte_count =
ElementOffsetFromIndex(character_count, from_kind);
TNode<IntPtrT> limit_offset = IntPtrAdd(from_offset, byte_count);
// Prepare the fast loop
MachineType type =
from_one_byte ? MachineType::Uint8() : MachineType::Uint16();
MachineRepresentation rep = to_one_byte ? MachineRepresentation::kWord8
: MachineRepresentation::kWord16;
int from_increment = 1 << ElementsKindToShiftSize(from_kind);
int to_increment = 1 << ElementsKindToShiftSize(to_kind);
TVARIABLE(IntPtrT, current_to_offset, to_offset);
VariableList vars({&current_to_offset}, zone());
int to_index_constant = 0, from_index_constant = 0;
bool index_same = (from_encoding == to_encoding) &&
(from_index == to_index ||
(ToInt32Constant(from_index, &from_index_constant) &&
ToInt32Constant(to_index, &to_index_constant) &&
from_index_constant == to_index_constant));
BuildFastLoop<IntPtrT>(
vars, from_offset, limit_offset,
[&](TNode<IntPtrT> offset) {
StoreNoWriteBarrier(rep, to_string,
index_same ? offset : current_to_offset.value(),
Load(type, from_string, offset));
if (!index_same) {
Increment(&current_to_offset, to_increment);
}
},
from_increment, IndexAdvanceMode::kPost);
}
// A wrapper around CopyStringCharacters which determines the correct string
// encoding, allocates a corresponding sequential string, and then copies the
// given character range using CopyStringCharacters.
// |from_string| must be a sequential string.
// 0 <= |from_index| <= |from_index| + |character_count| < from_string.length.
template <typename T>
TNode<String> StringBuiltinsAssembler::AllocAndCopyStringCharacters(
TNode<T> from, TNode<Int32T> from_instance_type, TNode<IntPtrT> from_index,
TNode<IntPtrT> character_count) {
Label end(this), one_byte_sequential(this), two_byte_sequential(this);
TVARIABLE(String, var_result);
Branch(IsOneByteStringInstanceType(from_instance_type), &one_byte_sequential,
&two_byte_sequential);
// The subject string is a sequential one-byte string.
BIND(&one_byte_sequential);
{
TNode<String> result = AllocateSeqOneByteString(
Unsigned(TruncateIntPtrToInt32(character_count)));
CopyStringCharacters<T>(from, result, from_index, IntPtrConstant(0),
character_count, String::ONE_BYTE_ENCODING,
String::ONE_BYTE_ENCODING);
var_result = result;
Goto(&end);
}
// The subject string is a sequential two-byte string.
BIND(&two_byte_sequential);
{
TNode<String> result = AllocateSeqTwoByteString(
Unsigned(TruncateIntPtrToInt32(character_count)));
CopyStringCharacters<T>(from, result, from_index, IntPtrConstant(0),
character_count, String::TWO_BYTE_ENCODING,
String::TWO_BYTE_ENCODING);
var_result = result;
Goto(&end);
}
BIND(&end);
return var_result.value();
}
// TODO(v8:9880): Use UintPtrT here.
TNode<String> StringBuiltinsAssembler::SubString(TNode<String> string,
TNode<IntPtrT> from,
TNode<IntPtrT> to) {
TVARIABLE(String, var_result);
ToDirectStringAssembler to_direct(state(), string);
Label end(this), runtime(this);
const TNode<IntPtrT> substr_length = IntPtrSub(to, from);
const TNode<IntPtrT> string_length = LoadStringLengthAsWord(string);
// Begin dispatching based on substring length.
Label original_string_or_invalid_length(this);
GotoIf(UintPtrGreaterThanOrEqual(substr_length, string_length),
&original_string_or_invalid_length);
// A real substring (substr_length < string_length).
Label empty(this);
GotoIf(IntPtrEqual(substr_length, IntPtrConstant(0)), &empty);
Label single_char(this);
GotoIf(IntPtrEqual(substr_length, IntPtrConstant(1)), &single_char);
// Deal with different string types: update the index if necessary
// and extract the underlying string.
TNode<String> direct_string = to_direct.TryToDirect(&runtime);
TNode<IntPtrT> offset = IntPtrAdd(from, to_direct.offset());
const TNode<Int32T> instance_type = to_direct.instance_type();
// The subject string can only be external or sequential string of either
// encoding at this point.
Label external_string(this);
{
if (FLAG_string_slices) {
Label next(this);
// Short slice. Copy instead of slicing.
GotoIf(IntPtrLessThan(substr_length,
IntPtrConstant(SlicedString::kMinLength)),
&next);
// Allocate new sliced string.
Counters* counters = isolate()->counters();
IncrementCounter(counters->sub_string_native(), 1);
Label one_byte_slice(this), two_byte_slice(this);
Branch(IsOneByteStringInstanceType(to_direct.instance_type()),
&one_byte_slice, &two_byte_slice);
BIND(&one_byte_slice);
{
var_result = AllocateSlicedOneByteString(
Unsigned(TruncateIntPtrToInt32(substr_length)), direct_string,
SmiTag(offset));
Goto(&end);
}
BIND(&two_byte_slice);
{
var_result = AllocateSlicedTwoByteString(
Unsigned(TruncateIntPtrToInt32(substr_length)), direct_string,
SmiTag(offset));
Goto(&end);
}
BIND(&next);
}
// The subject string can only be external or sequential string of either
// encoding at this point.
GotoIf(to_direct.is_external(), &external_string);
var_result = AllocAndCopyStringCharacters(direct_string, instance_type,
offset, substr_length);
Counters* counters = isolate()->counters();
IncrementCounter(counters->sub_string_native(), 1);
Goto(&end);
}
// Handle external string.
BIND(&external_string);
{
const TNode<RawPtrT> fake_sequential_string =
to_direct.PointerToString(&runtime);
var_result = AllocAndCopyStringCharacters(
fake_sequential_string, instance_type, offset, substr_length);
Counters* counters = isolate()->counters();
IncrementCounter(counters->sub_string_native(), 1);
Goto(&end);
}
BIND(&empty);
{
var_result = EmptyStringConstant();
Goto(&end);
}
// Substrings of length 1 are generated through CharCodeAt and FromCharCode.
BIND(&single_char);
{
TNode<Int32T> char_code = StringCharCodeAt(string, Unsigned(from));
var_result = StringFromSingleCharCode(char_code);
Goto(&end);
}
BIND(&original_string_or_invalid_length);
{
CSA_ASSERT(this, IntPtrEqual(substr_length, string_length));
// Equal length - check if {from, to} == {0, str.length}.
GotoIf(UintPtrGreaterThan(from, IntPtrConstant(0)), &runtime);
// Return the original string (substr_length == string_length).
Counters* counters = isolate()->counters();
IncrementCounter(counters->sub_string_native(), 1);
var_result = string;
Goto(&end);
}
// Fall back to a runtime call.
BIND(&runtime);
{
var_result =
CAST(CallRuntime(Runtime::kStringSubstring, NoContextConstant(), string,
SmiTag(from), SmiTag(to)));
Goto(&end);
}
BIND(&end);
return var_result.value();
}
} // namespace internal
} // namespace v8