// 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; Node* StringBuiltinsAssembler::DirectStringData(Node* string, Node* string_instance_type) { // Compute the effective offset of the first character. VARIABLE(var_data, MachineType::PointerRepresentation()); 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.Bind(IntPtrAdd( IntPtrConstant(SeqOneByteString::kHeaderSize - kHeapObjectTag), BitcastTaggedToWord(string))); 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.Bind(LoadObjectField(string, ExternalString::kResourceDataOffset, MachineType::Pointer())); Goto(&if_join); } BIND(&if_join); return var_data.value(); } void StringBuiltinsAssembler::DispatchOnStringEncodings( Node* const lhs_instance_type, Node* 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. TNode const encoding_mask = Int32Constant(kStringEncodingMask); TNode const lhs_encoding = Word32And(lhs_instance_type, encoding_mask); TNode const rhs_encoding = Word32And(rhs_instance_type, encoding_mask); TNode const 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 Node* StringBuiltinsAssembler::CallSearchStringRaw(Node* const subject_ptr, Node* const subject_length, Node* const search_ptr, Node* const search_length, Node* const start_position) { TNode const function_addr = ExternalConstant( ExternalReference::search_string_raw()); TNode const isolate_ptr = ExternalConstant(ExternalReference::isolate_address(isolate())); MachineType type_ptr = MachineType::Pointer(); MachineType type_intptr = MachineType::IntPtr(); Node* const result = 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 StringBuiltinsAssembler::PointerToStringDataAtIndex( TNode string_data, TNode index, String::Encoding encoding) { const ElementsKind kind = (encoding == String::ONE_BYTE_ENCODING) ? UINT8_ELEMENTS : UINT16_ELEMENTS; TNode offset_in_bytes = ElementOffsetFromIndex(index, kind); return RawPtrAdd(string_data, offset_in_bytes); } void StringBuiltinsAssembler::GenerateStringEqual(TNode left, TNode 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 lhs_length = LoadStringLengthAsWord(left); TNode rhs_length = LoadStringLengthAsWord(right); // Strings with different lengths cannot be equal. GotoIf(WordNotEqual(lhs_length, rhs_length), &if_notequal); Goto(&restart); BIND(&restart); TNode lhs = var_left.value(); TNode rhs = var_right.value(); TNode lhs_instance_type = LoadInstanceType(lhs); TNode 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( SloppyTNode lhs, Node* lhs_instance_type, SloppyTNode rhs, Node* rhs_instance_type, TNode 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 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 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( Node* lhs, Node* lhs_instance_type, MachineType lhs_type, Node* rhs, Node* rhs_instance_type, MachineType rhs_type, TNode length, Label* if_equal, Label* if_not_equal) { CSA_ASSERT(this, IsString(lhs)); CSA_ASSERT(this, IsString(rhs)); CSA_ASSERT(this, WordEqual(LoadStringLengthAsWord(lhs), length)); CSA_ASSERT(this, WordEqual(LoadStringLengthAsWord(rhs), length)); // Compute the effective offset of the first character. Node* lhs_data = DirectStringData(lhs, lhs_instance_type); Node* 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 lhs_value = UncheckedCast( Load(lhs_type, lhs_data, WordShl(var_offset.value(), ElementSizeLog2Of(lhs_type.representation())))); TNode rhs_value = UncheckedCast( 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 StringBuiltinsAssembler::StringFromSingleUTF16EncodedCodePoint( TNode codepoint) { VARIABLE(var_result, MachineRepresentation::kTagged, 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.Bind(StringFromSingleCharCode(codepoint)); Goto(&return_result); } BIND(&if_isword32); { TNode value = AllocateSeqTwoByteString(2); StoreNoWriteBarrier( MachineRepresentation::kWord32, value, IntPtrConstant(SeqTwoByteString::kHeaderSize - kHeapObjectTag), codepoint); var_result.Bind(value); Goto(&return_result); } BIND(&return_result); return CAST(var_result.value()); } TNode StringBuiltinsAssembler::AllocateConsString(TNode length, TNode left, TNode right) { // Added string can be a cons string. Comment("Allocating ConsString"); TNode left_instance_type = LoadInstanceType(left); TNode 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 combined_instance_type = Word32And(left_instance_type, right_instance_type); TNode result_map = CAST(Select( IsSetWord32(combined_instance_type, kStringEncodingMask), [=] { return ConsOneByteStringMapConstant(); }, [=] { return ConsStringMapConstant(); })); TNode result = AllocateInNewSpace(ConsString::kSize); StoreMapNoWriteBarrier(result, result_map); StoreObjectFieldNoWriteBarrier(result, ConsString::kLengthOffset, length, MachineRepresentation::kWord32); StoreObjectFieldNoWriteBarrier(result, ConsString::kHashFieldOffset, Int32Constant(String::kEmptyHashField), MachineRepresentation::kWord32); StoreObjectFieldNoWriteBarrier(result, ConsString::kFirstOffset, left); StoreObjectFieldNoWriteBarrier(result, ConsString::kSecondOffset, right); return CAST(result); } TNode StringBuiltinsAssembler::StringAdd(Node* context, TNode left, TNode right) { 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 left_length = LoadStringLengthAsWord32(left); GotoIfNot(Word32Equal(left_length, Uint32Constant(0)), &check_right); result = right; Goto(&done_native); BIND(&check_right); TNode right_length = LoadStringLengthAsWord32(right); GotoIfNot(Word32Equal(right_length, Uint32Constant(0)), &cons); result = left; Goto(&done_native); BIND(&cons); { TNode 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); Variable* input_vars[2] = {&var_left, &var_right}; Label non_cons(this, 2, input_vars); 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 left_instance_type = LoadInstanceType(var_left.value()); TNode right_instance_type = LoadInstanceType(var_right.value()); // Compute intersection and difference of instance types. TNode ored_instance_types = Word32Or(left_instance_type, right_instance_type); TNode 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 word_left_length = Signed(ChangeUint32ToWord(left_length)); TNode 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, TNode instance_type, Label* can_deref, Label* cannot_deref) { TNode representation = Word32And(instance_type, Int32Constant(kStringRepresentationMask)); GotoIf(Word32Equal(representation, Int32Constant(kThinStringTag)), can_deref); GotoIf(Word32NotEqual(representation, Int32Constant(kConsStringTag)), cannot_deref); // Cons string. TNode rhs = LoadObjectField(string, ConsString::kSecondOffset); GotoIf(IsEmptyString(rhs), can_deref); Goto(cannot_deref); } void StringBuiltinsAssembler::DerefIndirectString(TVariable* var_string, TNode 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(ThinString::kActualOffset) == static_cast(ConsString::kFirstOffset)); *var_string = LoadObjectField(var_string->value(), ThinString::kActualOffset); } void StringBuiltinsAssembler::MaybeDerefIndirectString( TVariable* var_string, TNode 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* var_left, TNode left_instance_type, TVariable* var_right, TNode 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 StringBuiltinsAssembler::DerefIndirectString( TNode string, TNode instance_type, Label* cannot_deref) { Label deref(this); BranchIfCanDerefIndirectString(string, instance_type, &deref, cannot_deref); BIND(&deref); STATIC_ASSERT(static_cast(ThinString::kActualOffset) == static_cast(ConsString::kFirstOffset)); return LoadObjectField(string, ThinString::kActualOffset); } TF_BUILTIN(StringAdd_CheckNone, StringBuiltinsAssembler) { TNode left = CAST(Parameter(Descriptor::kLeft)); TNode right = CAST(Parameter(Descriptor::kRight)); Node* context = Parameter(Descriptor::kContext); Return(StringAdd(context, left, right)); } TF_BUILTIN(SubString, StringBuiltinsAssembler) { TNode string = CAST(Parameter(Descriptor::kString)); TNode from = CAST(Parameter(Descriptor::kFrom)); TNode to = CAST(Parameter(Descriptor::kTo)); Return(SubString(string, SmiUntag(from), SmiUntag(to))); } void StringBuiltinsAssembler::GenerateStringRelationalComparison( TNode left, TNode right, Operation op) { TVARIABLE(String, var_left, left); TVARIABLE(String, var_right, right); Variable* input_vars[2] = {&var_left, &var_right}; Label if_less(this), if_equal(this), if_greater(this); Label restart(this, 2, input_vars); Goto(&restart); BIND(&restart); TNode lhs = var_left.value(); TNode 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 lhs_instance_type = LoadInstanceType(lhs); TNode 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 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 lhs_length = LoadStringLengthAsWord(lhs); TNode rhs_length = LoadStringLengthAsWord(rhs); // Determine the minimum length. TNode length = IntPtrMin(lhs_length, rhs_length); // Compute the effective offset of the first character. TNode begin = IntPtrConstant(SeqOneByteString::kHeaderSize - kHeapObjectTag); // Compute the first offset after the string from the length. TNode 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 lhs_value = Load(lhs, var_offset.value()); TNode rhs_value = Load(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) { TNode left = CAST(Parameter(Descriptor::kLeft)); TNode right = CAST(Parameter(Descriptor::kRight)); GenerateStringEqual(left, right); } TF_BUILTIN(StringLessThan, StringBuiltinsAssembler) { TNode left = CAST(Parameter(Descriptor::kLeft)); TNode right = CAST(Parameter(Descriptor::kRight)); GenerateStringRelationalComparison(left, right, Operation::kLessThan); } TF_BUILTIN(StringLessThanOrEqual, StringBuiltinsAssembler) { TNode left = CAST(Parameter(Descriptor::kLeft)); TNode right = CAST(Parameter(Descriptor::kRight)); GenerateStringRelationalComparison(left, right, Operation::kLessThanOrEqual); } TF_BUILTIN(StringGreaterThan, StringBuiltinsAssembler) { TNode left = CAST(Parameter(Descriptor::kLeft)); TNode right = CAST(Parameter(Descriptor::kRight)); GenerateStringRelationalComparison(left, right, Operation::kGreaterThan); } TF_BUILTIN(StringGreaterThanOrEqual, StringBuiltinsAssembler) { TNode left = CAST(Parameter(Descriptor::kLeft)); TNode right = CAST(Parameter(Descriptor::kRight)); GenerateStringRelationalComparison(left, right, Operation::kGreaterThanOrEqual); } TF_BUILTIN(StringCodePointAt, StringBuiltinsAssembler) { Node* receiver = Parameter(Descriptor::kReceiver); Node* position = Parameter(Descriptor::kPosition); // TODO(sigurds) Figure out if passing length as argument pays off. TNode length = LoadStringLengthAsWord(receiver); // Load the character code at the {position} from the {receiver}. TNode code = LoadSurrogatePairAt(receiver, length, position, UnicodeEncoding::UTF32); // And return it as TaggedSigned value. // TODO(turbofan): Allow builtins to return values untagged. TNode result = SmiFromInt32(code); Return(result); } TF_BUILTIN(StringFromCodePointAt, StringBuiltinsAssembler) { TNode receiver = CAST(Parameter(Descriptor::kReceiver)); TNode position = UncheckedCast(Parameter(Descriptor::kPosition)); // TODO(sigurds) Figure out if passing length as argument pays off. TNode length = LoadStringLengthAsWord(receiver); // Load the character code at the {position} from the {receiver}. TNode code = LoadSurrogatePairAt(receiver, length, position, UnicodeEncoding::UTF16); // Create a String from the UTF16 encoded code point TNode 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. TNode argc = UncheckedCast(Parameter(Descriptor::kJSActualArgumentsCount)); Node* context = Parameter(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 code = arguments.AtIndex(0); TNode code32 = TruncateTaggedToWord32(context, code); TNode code16 = Signed(Word32And(code32, Int32Constant(String::kMaxUtf16CodeUnit))); TNode result = StringFromSingleCharCode(code16); arguments.PopAndReturn(result); } Node* code16 = nullptr; BIND(&if_notoneargument); { Label two_byte(this); // Assume that the resulting string contains only one-byte characters. TNode 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 arg) { TNode 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 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 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 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 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 arg) { TNode code32 = TruncateTaggedToWord32(context, arg); TNode code16 = Word32And(code32, Int32Constant(String::kMaxUtf16CodeUnit)); TNode 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( TNode const subject_string, TNode const search_string, TNode const position, const std::function)>& f_return) { TNode const int_zero = IntPtrConstant(0); TNode const search_length = LoadStringLengthAsWord(search_string); TNode const subject_length = LoadStringLengthAsWord(subject_string); TNode const 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. TNode const subject_ptr = subject_to_direct.PointerToData(&call_runtime_unchecked); TNode const search_ptr = search_to_direct.PointerToData(&call_runtime_unchecked); TNode const subject_offset = subject_to_direct.offset(); TNode const 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); { TNode const adjusted_subject_ptr = PointerToStringDataAtIndex( subject_ptr, subject_offset, String::ONE_BYTE_ENCODING); TNode const 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); { TNode const string_addr = RawPtrAdd(adjusted_subject_ptr, start_position); TNode const search_length = IntPtrSub(subject_length, start_position); TNode const search_byte = ChangeInt32ToIntPtr(Load(MachineType::Uint8(), adjusted_search_ptr)); TNode const memchr = ExternalConstant(ExternalReference::libc_memchr_function()); TNode const result_address = UncheckedCast( 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); TNode const result_index = IntPtrAdd(RawPtrSub(result_address, string_addr), start_position); f_return(SmiTag(result_index)); } BIND(&generic_fast_path); { Node* const result = CallSearchStringRaw( adjusted_subject_ptr, subject_length, adjusted_search_ptr, search_length, start_position); f_return(SmiTag(result)); } } BIND(&one_two); { TNode const adjusted_subject_ptr = PointerToStringDataAtIndex( subject_ptr, subject_offset, String::ONE_BYTE_ENCODING); TNode const adjusted_search_ptr = PointerToStringDataAtIndex( search_ptr, search_offset, String::TWO_BYTE_ENCODING); Node* const result = CallSearchStringRaw( adjusted_subject_ptr, subject_length, adjusted_search_ptr, search_length, start_position); f_return(SmiTag(result)); } BIND(&two_one); { TNode const adjusted_subject_ptr = PointerToStringDataAtIndex( subject_ptr, subject_offset, String::TWO_BYTE_ENCODING); TNode const adjusted_search_ptr = PointerToStringDataAtIndex( search_ptr, search_offset, String::ONE_BYTE_ENCODING); Node* const result = CallSearchStringRaw( adjusted_subject_ptr, subject_length, adjusted_search_ptr, search_length, start_position); f_return(SmiTag(result)); } BIND(&two_two); { TNode const adjusted_subject_ptr = PointerToStringDataAtIndex( subject_ptr, subject_offset, String::TWO_BYTE_ENCODING); TNode const adjusted_search_ptr = PointerToStringDataAtIndex( search_ptr, search_offset, String::TWO_BYTE_ENCODING); Node* const result = CallSearchStringRaw( 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 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) { TNode receiver = CAST(Parameter(Descriptor::kReceiver)); TNode search_string = CAST(Parameter(Descriptor::kSearchString)); TNode position = CAST(Parameter(Descriptor::kPosition)); StringIndexOf(receiver, search_string, position, [this](TNode result) { this->Return(result); }); } // ES6 String.prototype.includes(searchString [, position]) // #sec-string.prototype.includes TF_BUILTIN(StringPrototypeIncludes, StringIncludesIndexOfAssembler) { TNode argc = ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount)); TNode context = CAST(Parameter(Descriptor::kContext)); Generate(kIncludes, argc, context); } // ES6 String.prototype.indexOf(searchString [, position]) // #sec-string.prototype.indexof TF_BUILTIN(StringPrototypeIndexOf, StringIncludesIndexOfAssembler) { TNode argc = ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount)); TNode context = CAST(Parameter(Descriptor::kContext)); Generate(kIndexOf, argc, context); } void StringIncludesIndexOfAssembler::Generate(SearchVariant variant, TNode argc, TNode context) { CodeStubArguments arguments(this, argc); TNode const 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 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"); TNode const search = var_search_string.value(); TNode const 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 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; TNode const result = CallRuntime(runtime, context, receiver, var_search_string.value(), var_position.value()); arguments.PopAndReturn(result); } } void StringBuiltinsAssembler::MaybeCallFunctionAtSymbol( Node* const context, Node* const object, Node* const maybe_string, Handle symbol, DescriptorIndexNameValue additional_property_to_check, const NodeFunction0& regexp_call, const NodeFunction1& generic_call) { Label out(this); // Smis definitely don't have an attached symbol. GotoIf(TaggedIsSmi(object), &out); // 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); GotoIf(TaggedIsSmi(maybe_string), &slow_lookup); GotoIfNot(IsString(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( CAST(context), CAST(object), LoadMap(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); } GotoIf(IsNullOrUndefined(object), &out); // Fall back to a slow lookup of {object[symbol]}. // // The spec uses GetMethod({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. TNode const 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); } TNode StringBuiltinsAssembler::IndexOfDollarChar(Node* const context, Node* const string) { CSA_ASSERT(this, IsString(string)); TNode const dollar_string = HeapConstant( isolate()->factory()->LookupSingleCharacterStringFromCode('$')); TNode const dollar_ix = CAST(CallBuiltin(Builtins::kStringIndexOf, context, string, dollar_string, SmiConstant(0))); return dollar_ix; } compiler::Node* StringBuiltinsAssembler::GetSubstitution( Node* context, Node* subject_string, Node* match_start_index, Node* match_end_index, Node* replace_string) { CSA_ASSERT(this, IsString(subject_string)); CSA_ASSERT(this, IsString(replace_string)); CSA_ASSERT(this, TaggedIsPositiveSmi(match_start_index)); CSA_ASSERT(this, TaggedIsPositiveSmi(match_end_index)); VARIABLE(var_result, MachineRepresentation::kTagged, replace_string); Label runtime(this), out(this); // In this primitive implementation we simply look for the next '$' 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. TNode const dollar_index = IndexOfDollarChar(context, replace_string); Branch(SmiIsNegative(dollar_index), &out, &runtime); BIND(&runtime); { CSA_ASSERT(this, TaggedIsPositiveSmi(dollar_index)); TNode const matched = CallBuiltin(Builtins::kStringSubstring, context, subject_string, SmiUntag(match_start_index), SmiUntag(match_end_index)); TNode const replacement_string = CallRuntime(Runtime::kGetSubstitution, context, matched, subject_string, match_start_index, replace_string, dollar_index); var_result.Bind(replacement_string); Goto(&out); } BIND(&out); return var_result.value(); } // ES6 #sec-string.prototype.replace TF_BUILTIN(StringPrototypeReplace, StringBuiltinsAssembler) { Label out(this); TNode receiver = CAST(Parameter(Descriptor::kReceiver)); Node* const search = Parameter(Descriptor::kSearch); Node* const replace = Parameter(Descriptor::kReplace); TNode context = CAST(Parameter(Descriptor::kContext)); TNode const 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)); }, [=](Node* fn) { Callable call_callable = CodeFactory::Call(isolate()); Return(CallJS(call_callable, context, fn, search, receiver, replace)); }); // Convert {receiver} and {search} to strings. TNode const subject_string = ToString_Inline(context, receiver); TNode const search_string = ToString_Inline(context, search); TNode const subject_length = LoadStringLengthAsWord(subject_string); TNode const 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(replace), &next); TNode const subject_instance_type = LoadInstanceType(subject_string); GotoIfNot(IsConsStringInstanceType(subject_instance_type), &next); GotoIf(TaggedIsPositiveSmi(IndexOfDollarChar(context, replace)), &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)); 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). TNode const 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(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); } TNode const match_end_index = SmiAdd(match_start_index, SmiFromIntPtr(search_length)); VARIABLE(var_result, MachineRepresentation::kTagged, EmptyStringConstant()); // Compute the prefix. { Label next(this); GotoIf(SmiEqual(match_start_index, smi_zero), &next); TNode const prefix = CallBuiltin(Builtins::kStringSubstring, context, subject_string, IntPtrConstant(0), SmiUntag(match_start_index)); var_result.Bind(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(replace)), &if_iscallablereplace, &if_notcallablereplace); BIND(&if_iscallablereplace); { Callable call_callable = CodeFactory::Call(isolate()); Node* const replacement = CallJS(call_callable, context, replace, UndefinedConstant(), search_string, match_start_index, subject_string); TNode const replacement_string = ToString_Inline(context, replacement); var_result.Bind(CallBuiltin(Builtins::kStringAdd_CheckNone, context, var_result.value(), replacement_string)); Goto(&out); } BIND(&if_notcallablereplace); { TNode const replace_string = ToString_Inline(context, replace); Node* const replacement = GetSubstitution(context, subject_string, match_start_index, match_end_index, replace_string); var_result.Bind(CallBuiltin(Builtins::kStringAdd_CheckNone, context, var_result.value(), replacement)); Goto(&out); } BIND(&out); { TNode const suffix = CallBuiltin(Builtins::kStringSubstring, context, subject_string, SmiUntag(match_end_index), subject_length); TNode const 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 receiver, TNode maybe_regexp, TNode context) { Label call_regexp_match_search(this); Builtins::Name builtin; Handle 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)); }, [=](Node* fn) { Callable call_callable = CodeFactory::Call(isolate()); Return(CallJS(call_callable, context, fn, maybe_regexp, receiver)); }); // maybe_regexp is not a RegExp nor has [@@match / @@search] property. { RegExpBuiltinsAssembler regexp_asm(state()); TNode receiver_string = ToString_Inline(context, receiver); TNode native_context = LoadNativeContext(context); TNode regexp_function = CAST( LoadContextElement(native_context, Context::REGEXP_FUNCTION_INDEX)); TNode initial_map = CAST(LoadObjectField( regexp_function, JSFunction::kPrototypeOrInitialMapOffset)); TNode 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 maybe_func = GetProperty(context, regexp, symbol); Callable call_callable = CodeFactory::Call(isolate()); Return(CallJS(call_callable, context, maybe_func, regexp, receiver_string)); } } } }; // ES6 #sec-string.prototype.match TF_BUILTIN(StringPrototypeMatch, StringMatchSearchAssembler) { TNode receiver = CAST(Parameter(Descriptor::kReceiver)); TNode maybe_regexp = CAST(Parameter(Descriptor::kRegexp)); TNode context = CAST(Parameter(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"; TNode context = CAST(Parameter(Descriptor::kContext)); TNode maybe_regexp = CAST(Parameter(Descriptor::kRegexp)); TNode receiver = CAST(Parameter(Descriptor::kReceiver)); TNode native_context = LoadNativeContext(context); // 1. Let O be ? RequireObjectCoercible(this value). RequireObjectCoercible(context, receiver, method_name); // 2. If regexp is neither undefined nor null, then // 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 s = CAST(receiver); Return( RegExpPrototypeMatchAllImpl(context, native_context, maybe_regexp, s)); }; auto if_generic_call = [=](Node* fn) { Callable call_callable = CodeFactory::Call(isolate()); Return(CallJS(call_callable, 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); RegExpMatchAllAssembler regexp_asm(state()); // 3. Let S be ? ToString(O). TNode s = ToString_Inline(context, receiver); // 4. Let rx be ? RegExpCreate(R, "g"). TNode rx = regexp_asm.RegExpCreate(context, native_context, maybe_regexp, StringConstant("g")); // 5. Return ? Invoke(rx, @@matchAll, « S »). Callable callable = CodeFactory::Call(isolate()); TNode match_all_func = GetProperty(context, rx, isolate()->factory()->match_all_symbol()); Return(CallJS(callable, context, match_all_func, rx, s)); } // ES6 #sec-string.prototype.search TF_BUILTIN(StringPrototypeSearch, StringMatchSearchAssembler) { TNode receiver = CAST(Parameter(Descriptor::kReceiver)); TNode maybe_regexp = CAST(Parameter(Descriptor::kRegexp)); TNode context = CAST(Parameter(Descriptor::kContext)); Generate(kSearch, "String.prototype.search", receiver, maybe_regexp, context); } TNode StringBuiltinsAssembler::StringToArray( TNode context, TNode subject_string, TNode subject_length, TNode 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 instance_type = LoadInstanceType(subject_string); GotoIfNot(IsOneByteStringInstanceType(instance_type), &call_runtime); // Try to use cached one byte characters. { TNode length_smi = Select(TaggedIsSmi(limit_number), [=] { return SmiMin(CAST(limit_number), subject_length); }, [=] { return subject_length; }); TNode length = SmiToIntPtr(length_smi); ToDirectStringAssembler to_direct(state(), subject_string); to_direct.TryToDirect(&call_runtime); TNode elements = CAST(AllocateFixedArray( PACKED_ELEMENTS, length, AllocationFlag::kAllowLargeObjectAllocation)); // Don't allocate anything while {string_data} is live! TNode string_data = to_direct.PointerToData(&fill_thehole_and_call_runtime); TNode string_data_offset = to_direct.offset(); TNode cache = SingleCharacterStringCacheConstant(); BuildFastLoop( IntPtrConstant(0), length, [&](TNode 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 char_code = UncheckedCast(Load(MachineType::Uint8(), string_data, IntPtrAdd(index, string_data_offset))); TNode code_index = ChangeUint32ToWord(char_code); TNode 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 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; TNode const argc = ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount)); CodeStubArguments args(this, argc); TNode receiver = args.GetReceiver(); TNode const separator = args.GetOptionalArgumentValue(kSeparatorArg); TNode const limit = args.GetOptionalArgumentValue(kLimitArg); TNode context = CAST(Parameter(Descriptor::kContext)); TNode 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)); }, [&](Node* fn) { Callable call_callable = CodeFactory::Call(isolate()); args.PopAndReturn( CallJS(call_callable, context, fn, separator, receiver, limit)); }); // String and integer conversions. TNode subject_string = ToString_Inline(context, receiver); TNode limit_number = Select( IsUndefined(limit), [=] { return NumberConstant(kMaxUInt32); }, [=] { return ToUint32(context, limit); }); TNode const 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; TNode const native_context = LoadNativeContext(context); TNode array_map = LoadJSArrayElementsMap(kind, native_context); TNode length = SmiConstant(1); TNode capacity = IntPtrConstant(1); TNode result = AllocateJSArray(kind, array_map, capacity, length); TNode 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 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); } TNode const result = CallRuntime(Runtime::kStringSplit, context, subject_string, separator_string, limit_number); args.PopAndReturn(result); BIND(&return_empty_array); { const ElementsKind kind = PACKED_ELEMENTS; TNode const native_context = LoadNativeContext(context); TNode array_map = LoadJSArrayElementsMap(kind, native_context); TNode length = smi_zero; TNode capacity = IntPtrConstant(0); TNode result = AllocateJSArray(kind, array_map, capacity, length); args.PopAndReturn(result); } } // ES6 #sec-string.prototype.substr TF_BUILTIN(StringPrototypeSubstr, StringBuiltinsAssembler) { const int kStartArg = 0; const int kLengthArg = 1; TNode const argc = ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount)); CodeStubArguments args(this, argc); TNode receiver = args.GetReceiver(); TNode start = args.GetOptionalArgumentValue(kStartArg); TNode length = args.GetOptionalArgumentValue(kLengthArg); TNode context = CAST(Parameter(Descriptor::kContext)); Label out(this); TVARIABLE(IntPtrT, var_start); TVARIABLE(Number, var_length); TNode const zero = IntPtrConstant(0); // Check that {receiver} is coercible to Object and convert it to a String. TNode const string = ToThisString(context, receiver, "String.prototype.substr"); TNode const string_length = LoadStringLengthAsWord(string); // Convert {start} to a relative index. var_start = ConvertToRelativeIndex(context, start, string_length); // Conversions and bounds-checks for {length}. Label if_issmi(this), if_isheapnumber(this, Label::kDeferred); // Default to {string_length} if {length} is undefined. { Label if_isundefined(this, Label::kDeferred), if_isnotundefined(this); Branch(IsUndefined(length), &if_isundefined, &if_isnotundefined); BIND(&if_isundefined); var_length = SmiTag(string_length); Goto(&if_issmi); BIND(&if_isnotundefined); var_length = ToInteger_Inline(context, length, CodeStubAssembler::kTruncateMinusZero); } TVARIABLE(IntPtrT, var_result_length); Branch(TaggedIsSmi(var_length.value()), &if_issmi, &if_isheapnumber); // Set {length} to min(max({length}, 0), {string_length} - {start} BIND(&if_issmi); { TNode const positive_length = IntPtrMax(SmiUntag(CAST(var_length.value())), zero); TNode const minimal_length = IntPtrSub(string_length, var_start.value()); var_result_length = IntPtrMin(positive_length, minimal_length); GotoIfNot(IntPtrLessThanOrEqual(var_result_length.value(), zero), &out); args.PopAndReturn(EmptyStringConstant()); } BIND(&if_isheapnumber); { // If {length} is a heap number, it is definitely out of bounds. There are // two cases according to the spec: if it is negative, "" is returned; if // it is positive, then length is set to {string_length} - {start}. CSA_ASSERT(this, IsHeapNumber(CAST(var_length.value()))); Label if_isnegative(this), if_ispositive(this); TNode const float_zero = Float64Constant(0.); TNode const length_float = LoadHeapNumberValue(CAST(var_length.value())); Branch(Float64LessThan(length_float, float_zero), &if_isnegative, &if_ispositive); BIND(&if_isnegative); args.PopAndReturn(EmptyStringConstant()); BIND(&if_ispositive); { var_result_length = IntPtrSub(string_length, var_start.value()); GotoIfNot(IntPtrLessThanOrEqual(var_result_length.value(), zero), &out); args.PopAndReturn(EmptyStringConstant()); } } BIND(&out); { TNode const end = IntPtrAdd(var_start.value(), var_result_length.value()); args.PopAndReturn(SubString(string, var_start.value(), end)); } } TF_BUILTIN(StringSubstring, StringBuiltinsAssembler) { TNode string = CAST(Parameter(Descriptor::kString)); TNode from = UncheckedCast(Parameter(Descriptor::kFrom)); TNode to = UncheckedCast(Parameter(Descriptor::kTo)); Return(SubString(string, from, to)); } // ES6 #sec-string.prototype.trim TF_BUILTIN(StringPrototypeTrim, StringTrimAssembler) { TNode argc = ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount)); TNode context = CAST(Parameter(Descriptor::kContext)); Generate(String::kTrim, "String.prototype.trim", argc, context); } // https://github.com/tc39/proposal-string-left-right-trim TF_BUILTIN(StringPrototypeTrimStart, StringTrimAssembler) { TNode argc = ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount)); TNode context = CAST(Parameter(Descriptor::kContext)); Generate(String::kTrimStart, "String.prototype.trimLeft", argc, context); } // https://github.com/tc39/proposal-string-left-right-trim TF_BUILTIN(StringPrototypeTrimEnd, StringTrimAssembler) { TNode argc = ChangeInt32ToIntPtr(Parameter(Descriptor::kJSActualArgumentsCount)); TNode context = CAST(Parameter(Descriptor::kContext)); Generate(String::kTrimEnd, "String.prototype.trimRight", argc, context); } void StringTrimAssembler::Generate(String::TrimMode mode, const char* method_name, TNode argc, TNode context) { Label return_emptystring(this), if_runtime(this); CodeStubArguments arguments(this, argc); TNode receiver = arguments.GetReceiver(); // Check that {receiver} is coercible to Object and convert it to a String. TNode const string = ToThisString(context, receiver, method_name); TNode const string_length = LoadStringLengthAsWord(string); ToDirectStringAssembler to_direct(state(), string); to_direct.TryToDirect(&if_runtime); TNode const string_data = to_direct.PointerToData(&if_runtime); TNode const instance_type = to_direct.instance_type(); TNode const is_stringonebyte = IsOneByteStringInstanceType(instance_type); TNode const string_data_offset = to_direct.offset(); TVARIABLE(IntPtrT, var_start, IntPtrConstant(0)); TVARIABLE(IntPtrT, var_end, IntPtrSub(string_length, IntPtrConstant(1))); if (mode == String::kTrimStart || mode == String::kTrim) { ScanForNonWhiteSpaceOrLineTerminator(string_data, string_data_offset, is_stringonebyte, &var_start, string_length, 1, &return_emptystring); } if (mode == String::kTrimEnd || mode == String::kTrim) { ScanForNonWhiteSpaceOrLineTerminator( string_data, string_data_offset, is_stringonebyte, &var_end, IntPtrConstant(-1), -1, &return_emptystring); } arguments.PopAndReturn( SubString(string, var_start.value(), IntPtrAdd(var_end.value(), IntPtrConstant(1)))); BIND(&if_runtime); arguments.PopAndReturn( CallRuntime(Runtime::kStringTrim, context, string, SmiConstant(mode))); BIND(&return_emptystring); arguments.PopAndReturn(EmptyStringConstant()); } void StringTrimAssembler::ScanForNonWhiteSpaceOrLineTerminator( Node* const string_data, Node* const string_data_offset, Node* const is_stringonebyte, TVariable* const var_index, TNode const end, int increment, Label* const if_none_found) { Label if_stringisonebyte(this), out(this); GotoIf(is_stringonebyte, &if_stringisonebyte); // Two Byte String BuildLoop( var_index, end, increment, if_none_found, &out, [&](Node* const index) { return Load( MachineType::Uint16(), string_data, WordShl(IntPtrAdd(index, string_data_offset), IntPtrConstant(1))); }); BIND(&if_stringisonebyte); BuildLoop(var_index, end, increment, if_none_found, &out, [&](Node* const index) { return Load(MachineType::Uint8(), string_data, IntPtrAdd(index, string_data_offset)); }); BIND(&out); } void StringTrimAssembler::BuildLoop( TVariable* const var_index, TNode const end, int increment, Label* const if_none_found, Label* const out, const std::function& get_character) { Label loop(this, var_index); Goto(&loop); BIND(&loop); { TNode index = var_index->value(); GotoIf(IntPtrEqual(index, end), if_none_found); GotoIfNotWhiteSpaceOrLineTerminator( UncheckedCast(get_character(index)), out); Increment(var_index, increment); Goto(&loop); } } void StringTrimAssembler::GotoIfNotWhiteSpaceOrLineTerminator( TNode const char_code, Label* const if_not_whitespace) { Label out(this); // 0x0020 - SPACE (Intentionally out of order to fast path a commmon case) GotoIf(Word32Equal(char_code, Int32Constant(0x0020)), &out); // 0x0009 - HORIZONTAL TAB GotoIf(Uint32LessThan(char_code, Int32Constant(0x0009)), if_not_whitespace); // 0x000A - LINE FEED OR NEW LINE // 0x000B - VERTICAL TAB // 0x000C - FORMFEED // 0x000D - HORIZONTAL TAB GotoIf(Uint32LessThanOrEqual(char_code, Int32Constant(0x000D)), &out); // Common Non-whitespace characters GotoIf(Uint32LessThan(char_code, Int32Constant(0x00A0)), if_not_whitespace); // 0x00A0 - NO-BREAK SPACE GotoIf(Word32Equal(char_code, Int32Constant(0x00A0)), &out); // 0x1680 - Ogham Space Mark GotoIf(Word32Equal(char_code, Int32Constant(0x1680)), &out); // 0x2000 - EN QUAD GotoIf(Uint32LessThan(char_code, Int32Constant(0x2000)), if_not_whitespace); // 0x2001 - EM QUAD // 0x2002 - EN SPACE // 0x2003 - EM SPACE // 0x2004 - THREE-PER-EM SPACE // 0x2005 - FOUR-PER-EM SPACE // 0x2006 - SIX-PER-EM SPACE // 0x2007 - FIGURE SPACE // 0x2008 - PUNCTUATION SPACE // 0x2009 - THIN SPACE // 0x200A - HAIR SPACE GotoIf(Uint32LessThanOrEqual(char_code, Int32Constant(0x200A)), &out); // 0x2028 - LINE SEPARATOR GotoIf(Word32Equal(char_code, Int32Constant(0x2028)), &out); // 0x2029 - PARAGRAPH SEPARATOR GotoIf(Word32Equal(char_code, Int32Constant(0x2029)), &out); // 0x202F - NARROW NO-BREAK SPACE GotoIf(Word32Equal(char_code, Int32Constant(0x202F)), &out); // 0x205F - MEDIUM MATHEMATICAL SPACE GotoIf(Word32Equal(char_code, Int32Constant(0x205F)), &out); // 0xFEFF - BYTE ORDER MARK GotoIf(Word32Equal(char_code, Int32Constant(0xFEFF)), &out); // 0x3000 - IDEOGRAPHIC SPACE Branch(Word32Equal(char_code, Int32Constant(0x3000)), &out, if_not_whitespace); BIND(&out); } // Return the |word32| codepoint at {index}. Supports SeqStrings and // ExternalStrings. TNode StringBuiltinsAssembler::LoadSurrogatePairAt( SloppyTNode string, SloppyTNode length, SloppyTNode index, UnicodeEncoding encoding) { Label handle_surrogate_pair(this), return_result(this); TVARIABLE(Int32T, var_result); TVARIABLE(Int32T, var_trail); var_result = StringCharCodeAt(string, index); var_trail = Int32Constant(0); GotoIf(Word32NotEqual(Word32And(var_result.value(), Int32Constant(0xFC00)), Int32Constant(0xD800)), &return_result); TNode next_index = IntPtrAdd(index, IntPtrConstant(1)); GotoIfNot(IntPtrLessThan(next_index, length), &return_result); var_trail = StringCharCodeAt(string, next_index); Branch(Word32Equal(Word32And(var_trail.value(), Int32Constant(0xFC00)), Int32Constant(0xDC00)), &handle_surrogate_pair, &return_result); BIND(&handle_surrogate_pair); { TNode lead = var_result.value(); TNode 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 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, TNode 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 protector_cell = StringIteratorProtectorConstant(); DCHECK(isolate()->heap()->string_iterator_protector().IsPropertyCell()); Branch( TaggedEqual(LoadObjectField(protector_cell, PropertyCell::kValueOffset), SmiConstant(Protectors::kProtectorValid)), if_true, if_false); } void StringBuiltinsAssembler::CopyStringCharacters( Node* from_string, Node* to_string, TNode from_index, TNode to_index, TNode character_count, String::Encoding from_encoding, String::Encoding to_encoding) { // Cannot assert IsString(from_string) and IsString(to_string) here because // SubString can 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 from_offset = ElementOffsetFromIndex(from_index, from_kind, header_size); TNode to_offset = ElementOffsetFromIndex(to_index, to_kind, header_size); TNode byte_count = ElementOffsetFromIndex(character_count, from_kind); TNode 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({¤t_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( vars, from_offset, limit_offset, [&](TNode offset) { Node* value = Load(type, from_string, offset); StoreNoWriteBarrier(rep, to_string, index_same ? offset : current_to_offset.value(), value); if (!index_same) { Increment(¤t_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. TNode StringBuiltinsAssembler::AllocAndCopyStringCharacters( Node* from, Node* from_instance_type, TNode from_index, TNode 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 result = AllocateSeqOneByteString( Unsigned(TruncateIntPtrToInt32(character_count))); CopyStringCharacters(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 result = AllocateSeqTwoByteString( Unsigned(TruncateIntPtrToInt32(character_count))); CopyStringCharacters(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(); } TNode StringBuiltinsAssembler::SubString(TNode string, TNode from, TNode to) { TVARIABLE(String, var_result); ToDirectStringAssembler to_direct(state(), string); Label end(this), runtime(this); TNode const substr_length = IntPtrSub(to, from); TNode const 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 direct_string = to_direct.TryToDirect(&runtime); TNode offset = IntPtrAdd(from, to_direct.offset()); TNode const 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); { TNode const 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 char_code = StringCharCodeAt(string, 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