src/builtins/builtins-sharedarraybuffer.cc - v8/v8 - Git at Google

 // Copyright 2016 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.h"
 #include "src/builtins/builtins-utils.h"

 #include "src/code-factory.h"

 namespace v8 {
 namespace internal {

 // ES7 sharedmem 6.3.4.1 get SharedArrayBuffer.prototype.byteLength
 BUILTIN(SharedArrayBufferPrototypeGetByteLength) {
   HandleScope scope(isolate);
   CHECK_RECEIVER(JSArrayBuffer, array_buffer,
                  "get SharedArrayBuffer.prototype.byteLength");
   if (!array_buffer->is_shared()) {
     THROW_NEW_ERROR_RETURN_FAILURE(
         isolate, NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
                               isolate->factory()->NewStringFromAsciiChecked(
                                   "get SharedArrayBuffer.prototype.byteLength"),
                               args.receiver()));
   }
   return array_buffer->byte_length();
 }

 namespace {

 void ValidateSharedTypedArray(CodeStubAssembler* a, compiler::Node* tagged,
                               compiler::Node* context,
                               compiler::Node** out_instance_type,
                               compiler::Node** out_backing_store) {
   using namespace compiler;
   CodeStubAssembler::Label is_smi(a), not_smi(a), is_typed_array(a),
       not_typed_array(a), is_shared(a), not_shared(a), is_float_or_clamped(a),
       not_float_or_clamped(a), invalid(a);

   // Fail if it is not a heap object.
   a->Branch(a->TaggedIsSmi(tagged), &is_smi, &not_smi);
   a->Bind(&is_smi);
   a->Goto(&invalid);

   // Fail if the array's instance type is not JSTypedArray.
   a->Bind(&not_smi);
   a->Branch(a->WordEqual(a->LoadInstanceType(tagged),
                          a->Int32Constant(JS_TYPED_ARRAY_TYPE)),
             &is_typed_array, &not_typed_array);
   a->Bind(&not_typed_array);
   a->Goto(&invalid);

   // Fail if the array's JSArrayBuffer is not shared.
   a->Bind(&is_typed_array);
   Node* array_buffer = a->LoadObjectField(tagged, JSTypedArray::kBufferOffset);
   Node* is_buffer_shared =
       a->IsSetWord32<JSArrayBuffer::IsShared>(a->LoadObjectField(
           array_buffer, JSArrayBuffer::kBitFieldOffset, MachineType::Uint32()));
   a->Branch(is_buffer_shared, &is_shared, &not_shared);
   a->Bind(&not_shared);
   a->Goto(&invalid);

   // Fail if the array's element type is float32, float64 or clamped.
   a->Bind(&is_shared);
   Node* elements_instance_type = a->LoadInstanceType(
       a->LoadObjectField(tagged, JSObject::kElementsOffset));
   STATIC_ASSERT(FIXED_INT8_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
   STATIC_ASSERT(FIXED_INT16_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
   STATIC_ASSERT(FIXED_INT32_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
   STATIC_ASSERT(FIXED_UINT8_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
   STATIC_ASSERT(FIXED_UINT16_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
   STATIC_ASSERT(FIXED_UINT32_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
   a->Branch(a->Int32LessThan(elements_instance_type,
                              a->Int32Constant(FIXED_FLOAT32_ARRAY_TYPE)),
             &not_float_or_clamped, &is_float_or_clamped);
   a->Bind(&is_float_or_clamped);
   a->Goto(&invalid);

   a->Bind(&invalid);
   a->CallRuntime(Runtime::kThrowNotIntegerSharedTypedArrayError, context,
                  tagged);
   a->Return(a->UndefinedConstant());

   a->Bind(&not_float_or_clamped);
   *out_instance_type = elements_instance_type;

   Node* backing_store =
       a->LoadObjectField(array_buffer, JSArrayBuffer::kBackingStoreOffset);
   Node* byte_offset = a->ChangeUint32ToWord(a->TruncateTaggedToWord32(
       context,
       a->LoadObjectField(tagged, JSArrayBufferView::kByteOffsetOffset)));
   *out_backing_store = a->IntPtrAdd(backing_store, byte_offset);
 }

 // https://tc39.github.io/ecmascript_sharedmem/shmem.html#Atomics.ValidateAtomicAccess
 compiler::Node* ConvertTaggedAtomicIndexToWord32(CodeStubAssembler* a,
                                                  compiler::Node* tagged,
                                                  compiler::Node* context) {
   using namespace compiler;
   CodeStubAssembler::Variable var_result(a, MachineRepresentation::kWord32);

   Callable to_number = CodeFactory::ToNumber(a->isolate());
   Node* number_index = a->CallStub(to_number, context, tagged);
   CodeStubAssembler::Label done(a, &var_result);

   CodeStubAssembler::Label if_numberissmi(a), if_numberisnotsmi(a);
   a->Branch(a->TaggedIsSmi(number_index), &if_numberissmi, &if_numberisnotsmi);

   a->Bind(&if_numberissmi);
   {
     var_result.Bind(a->SmiToWord32(number_index));
     a->Goto(&done);
   }

   a->Bind(&if_numberisnotsmi);
   {
     Node* number_index_value = a->LoadHeapNumberValue(number_index);
     Node* access_index = a->TruncateFloat64ToWord32(number_index_value);
     Node* test_index = a->ChangeInt32ToFloat64(access_index);

     CodeStubAssembler::Label if_indexesareequal(a), if_indexesarenotequal(a);
     a->Branch(a->Float64Equal(number_index_value, test_index),
               &if_indexesareequal, &if_indexesarenotequal);

     a->Bind(&if_indexesareequal);
     {
       var_result.Bind(access_index);
       a->Goto(&done);
     }

     a->Bind(&if_indexesarenotequal);
     a->Return(
         a->CallRuntime(Runtime::kThrowInvalidAtomicAccessIndexError, context));
   }

   a->Bind(&done);
   return var_result.value();
 }

 void ValidateAtomicIndex(CodeStubAssembler* a, compiler::Node* index_word,
                          compiler::Node* array_length_word,
                          compiler::Node* context) {
   using namespace compiler;
   // Check if the index is in bounds. If not, throw RangeError.
   CodeStubAssembler::Label if_inbounds(a), if_notinbounds(a);
   // TODO(jkummerow): Use unsigned comparison instead of "i<0 || i>length".
   a->Branch(
       a->WordOr(a->Int32LessThan(index_word, a->Int32Constant(0)),
                 a->Int32GreaterThanOrEqual(index_word, array_length_word)),
       &if_notinbounds, &if_inbounds);
   a->Bind(&if_notinbounds);
   a->Return(
       a->CallRuntime(Runtime::kThrowInvalidAtomicAccessIndexError, context));
   a->Bind(&if_inbounds);
 }

 }  // anonymous namespace

 void Builtins::Generate_AtomicsLoad(CodeStubAssembler* a) {
   using namespace compiler;
   Node* array = a->Parameter(1);
   Node* index = a->Parameter(2);
   Node* context = a->Parameter(3 + 2);

   Node* instance_type;
   Node* backing_store;
   ValidateSharedTypedArray(a, array, context, &instance_type, &backing_store);

   Node* index_word32 = ConvertTaggedAtomicIndexToWord32(a, index, context);
   Node* array_length_word32 = a->TruncateTaggedToWord32(
       context, a->LoadObjectField(array, JSTypedArray::kLengthOffset));
   ValidateAtomicIndex(a, index_word32, array_length_word32, context);
   Node* index_word = a->ChangeUint32ToWord(index_word32);

   CodeStubAssembler::Label i8(a), u8(a), i16(a), u16(a), i32(a), u32(a),
       other(a);
   int32_t case_values[] = {
       FIXED_INT8_ARRAY_TYPE,   FIXED_UINT8_ARRAY_TYPE, FIXED_INT16_ARRAY_TYPE,
       FIXED_UINT16_ARRAY_TYPE, FIXED_INT32_ARRAY_TYPE, FIXED_UINT32_ARRAY_TYPE,
   };
   CodeStubAssembler::Label* case_labels[] = {
       &i8, &u8, &i16, &u16, &i32, &u32,
   };
   a->Switch(instance_type, &other, case_values, case_labels,
             arraysize(case_labels));

   a->Bind(&i8);
   a->Return(
       a->SmiTag(a->AtomicLoad(MachineType::Int8(), backing_store, index_word)));

   a->Bind(&u8);
   a->Return(a->SmiTag(
       a->AtomicLoad(MachineType::Uint8(), backing_store, index_word)));

   a->Bind(&i16);
   a->Return(a->SmiTag(a->AtomicLoad(MachineType::Int16(), backing_store,
                                     a->WordShl(index_word, 1))));

   a->Bind(&u16);
   a->Return(a->SmiTag(a->AtomicLoad(MachineType::Uint16(), backing_store,
                                     a->WordShl(index_word, 1))));

   a->Bind(&i32);
   a->Return(a->ChangeInt32ToTagged(a->AtomicLoad(
       MachineType::Int32(), backing_store, a->WordShl(index_word, 2))));

   a->Bind(&u32);
   a->Return(a->ChangeUint32ToTagged(a->AtomicLoad(
       MachineType::Uint32(), backing_store, a->WordShl(index_word, 2))));

   // This shouldn't happen, we've already validated the type.
   a->Bind(&other);
   a->Return(a->Int32Constant(0));
 }

 void Builtins::Generate_AtomicsStore(CodeStubAssembler* a) {
   using namespace compiler;
   Node* array = a->Parameter(1);
   Node* index = a->Parameter(2);
   Node* value = a->Parameter(3);
   Node* context = a->Parameter(4 + 2);

   Node* instance_type;
   Node* backing_store;
   ValidateSharedTypedArray(a, array, context, &instance_type, &backing_store);

   Node* index_word32 = ConvertTaggedAtomicIndexToWord32(a, index, context);
   Node* array_length_word32 = a->TruncateTaggedToWord32(
       context, a->LoadObjectField(array, JSTypedArray::kLengthOffset));
   ValidateAtomicIndex(a, index_word32, array_length_word32, context);
   Node* index_word = a->ChangeUint32ToWord(index_word32);

   Node* value_integer = a->ToInteger(context, value);
   Node* value_word32 = a->TruncateTaggedToWord32(context, value_integer);

   CodeStubAssembler::Label u8(a), u16(a), u32(a), other(a);
   int32_t case_values[] = {
       FIXED_INT8_ARRAY_TYPE,   FIXED_UINT8_ARRAY_TYPE, FIXED_INT16_ARRAY_TYPE,
       FIXED_UINT16_ARRAY_TYPE, FIXED_INT32_ARRAY_TYPE, FIXED_UINT32_ARRAY_TYPE,
   };
   CodeStubAssembler::Label* case_labels[] = {
       &u8, &u8, &u16, &u16, &u32, &u32,
   };
   a->Switch(instance_type, &other, case_values, case_labels,
             arraysize(case_labels));

   a->Bind(&u8);
   a->AtomicStore(MachineRepresentation::kWord8, backing_store, index_word,
                  value_word32);
   a->Return(value_integer);

   a->Bind(&u16);
   a->AtomicStore(MachineRepresentation::kWord16, backing_store,
                  a->WordShl(index_word, 1), value_word32);
   a->Return(value_integer);

   a->Bind(&u32);
   a->AtomicStore(MachineRepresentation::kWord32, backing_store,
                  a->WordShl(index_word, 2), value_word32);
   a->Return(value_integer);

   // This shouldn't happen, we've already validated the type.
   a->Bind(&other);
   a->Return(a->Int32Constant(0));
 }

 }  // namespace internal
 }  // namespace v8
	// Copyright 2016 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.h"
	#include "src/builtins/builtins-utils.h"

	#include "src/code-factory.h"

	namespace v8 {
	namespace internal {

	// ES7 sharedmem 6.3.4.1 get SharedArrayBuffer.prototype.byteLength
	BUILTIN(SharedArrayBufferPrototypeGetByteLength) {
	HandleScope scope(isolate);
	CHECK_RECEIVER(JSArrayBuffer, array_buffer,
	"get SharedArrayBuffer.prototype.byteLength");
	if (!array_buffer->is_shared()) {
	THROW_NEW_ERROR_RETURN_FAILURE(
	isolate, NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
	isolate->factory()->NewStringFromAsciiChecked(
	"get SharedArrayBuffer.prototype.byteLength"),
	args.receiver()));
	}
	return array_buffer->byte_length();
	}

	namespace {

	void ValidateSharedTypedArray(CodeStubAssembler* a, compiler::Node* tagged,
	compiler::Node* context,
	compiler::Node** out_instance_type,
	compiler::Node** out_backing_store) {
	using namespace compiler;
	CodeStubAssembler::Label is_smi(a), not_smi(a), is_typed_array(a),
	not_typed_array(a), is_shared(a), not_shared(a), is_float_or_clamped(a),
	not_float_or_clamped(a), invalid(a);

	// Fail if it is not a heap object.
	a->Branch(a->TaggedIsSmi(tagged), &is_smi, &not_smi);
	a->Bind(&is_smi);
	a->Goto(&invalid);

	// Fail if the array's instance type is not JSTypedArray.
	a->Bind(&not_smi);
	a->Branch(a->WordEqual(a->LoadInstanceType(tagged),
	a->Int32Constant(JS_TYPED_ARRAY_TYPE)),
	&is_typed_array, &not_typed_array);
	a->Bind(&not_typed_array);
	a->Goto(&invalid);

	// Fail if the array's JSArrayBuffer is not shared.
	a->Bind(&is_typed_array);
	Node* array_buffer = a->LoadObjectField(tagged, JSTypedArray::kBufferOffset);
	Node* is_buffer_shared =
	a->IsSetWord32<JSArrayBuffer::IsShared>(a->LoadObjectField(
	array_buffer, JSArrayBuffer::kBitFieldOffset, MachineType::Uint32()));
	a->Branch(is_buffer_shared, &is_shared, &not_shared);
	a->Bind(&not_shared);
	a->Goto(&invalid);

	// Fail if the array's element type is float32, float64 or clamped.
	a->Bind(&is_shared);
	Node* elements_instance_type = a->LoadInstanceType(
	a->LoadObjectField(tagged, JSObject::kElementsOffset));
	STATIC_ASSERT(FIXED_INT8_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
	STATIC_ASSERT(FIXED_INT16_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
	STATIC_ASSERT(FIXED_INT32_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
	STATIC_ASSERT(FIXED_UINT8_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
	STATIC_ASSERT(FIXED_UINT16_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
	STATIC_ASSERT(FIXED_UINT32_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
	a->Branch(a->Int32LessThan(elements_instance_type,
	a->Int32Constant(FIXED_FLOAT32_ARRAY_TYPE)),
	&not_float_or_clamped, &is_float_or_clamped);
	a->Bind(&is_float_or_clamped);
	a->Goto(&invalid);

	a->Bind(&invalid);
	a->CallRuntime(Runtime::kThrowNotIntegerSharedTypedArrayError, context,
	tagged);
	a->Return(a->UndefinedConstant());

	a->Bind(&not_float_or_clamped);
	*out_instance_type = elements_instance_type;

	Node* backing_store =
	a->LoadObjectField(array_buffer, JSArrayBuffer::kBackingStoreOffset);
	Node* byte_offset = a->ChangeUint32ToWord(a->TruncateTaggedToWord32(
	context,
	a->LoadObjectField(tagged, JSArrayBufferView::kByteOffsetOffset)));
	*out_backing_store = a->IntPtrAdd(backing_store, byte_offset);
	}

	// https://tc39.github.io/ecmascript_sharedmem/shmem.html#Atomics.ValidateAtomicAccess
	compiler::Node* ConvertTaggedAtomicIndexToWord32(CodeStubAssembler* a,
	compiler::Node* tagged,
	compiler::Node* context) {
	using namespace compiler;
	CodeStubAssembler::Variable var_result(a, MachineRepresentation::kWord32);

	Callable to_number = CodeFactory::ToNumber(a->isolate());
	Node* number_index = a->CallStub(to_number, context, tagged);
	CodeStubAssembler::Label done(a, &var_result);

	CodeStubAssembler::Label if_numberissmi(a), if_numberisnotsmi(a);
	a->Branch(a->TaggedIsSmi(number_index), &if_numberissmi, &if_numberisnotsmi);

	a->Bind(&if_numberissmi);
	{
	var_result.Bind(a->SmiToWord32(number_index));
	a->Goto(&done);
	}

	a->Bind(&if_numberisnotsmi);
	{
	Node* number_index_value = a->LoadHeapNumberValue(number_index);
	Node* access_index = a->TruncateFloat64ToWord32(number_index_value);
	Node* test_index = a->ChangeInt32ToFloat64(access_index);

	CodeStubAssembler::Label if_indexesareequal(a), if_indexesarenotequal(a);
	a->Branch(a->Float64Equal(number_index_value, test_index),
	&if_indexesareequal, &if_indexesarenotequal);

	a->Bind(&if_indexesareequal);
	{
	var_result.Bind(access_index);
	a->Goto(&done);
	}

	a->Bind(&if_indexesarenotequal);
	a->Return(
	a->CallRuntime(Runtime::kThrowInvalidAtomicAccessIndexError, context));
	}

	a->Bind(&done);
	return var_result.value();
	}

	void ValidateAtomicIndex(CodeStubAssembler* a, compiler::Node* index_word,
	compiler::Node* array_length_word,
	compiler::Node* context) {
	using namespace compiler;
	// Check if the index is in bounds. If not, throw RangeError.
	CodeStubAssembler::Label if_inbounds(a), if_notinbounds(a);
	// TODO(jkummerow): Use unsigned comparison instead of "i<0 \|\| i>length".
	a->Branch(
	a->WordOr(a->Int32LessThan(index_word, a->Int32Constant(0)),
	a->Int32GreaterThanOrEqual(index_word, array_length_word)),
	&if_notinbounds, &if_inbounds);
	a->Bind(&if_notinbounds);
	a->Return(
	a->CallRuntime(Runtime::kThrowInvalidAtomicAccessIndexError, context));
	a->Bind(&if_inbounds);
	}

	} // anonymous namespace

	void Builtins::Generate_AtomicsLoad(CodeStubAssembler* a) {
	using namespace compiler;
	Node* array = a->Parameter(1);
	Node* index = a->Parameter(2);
	Node* context = a->Parameter(3 + 2);

	Node* instance_type;
	Node* backing_store;
	ValidateSharedTypedArray(a, array, context, &instance_type, &backing_store);

	Node* index_word32 = ConvertTaggedAtomicIndexToWord32(a, index, context);
	Node* array_length_word32 = a->TruncateTaggedToWord32(
	context, a->LoadObjectField(array, JSTypedArray::kLengthOffset));
	ValidateAtomicIndex(a, index_word32, array_length_word32, context);
	Node* index_word = a->ChangeUint32ToWord(index_word32);

	CodeStubAssembler::Label i8(a), u8(a), i16(a), u16(a), i32(a), u32(a),
	other(a);
	int32_t case_values[] = {
	FIXED_INT8_ARRAY_TYPE, FIXED_UINT8_ARRAY_TYPE, FIXED_INT16_ARRAY_TYPE,
	FIXED_UINT16_ARRAY_TYPE, FIXED_INT32_ARRAY_TYPE, FIXED_UINT32_ARRAY_TYPE,
	};
	CodeStubAssembler::Label* case_labels[] = {
	&i8, &u8, &i16, &u16, &i32, &u32,
	};
	a->Switch(instance_type, &other, case_values, case_labels,
	arraysize(case_labels));

	a->Bind(&i8);
	a->Return(
	a->SmiTag(a->AtomicLoad(MachineType::Int8(), backing_store, index_word)));

	a->Bind(&u8);
	a->Return(a->SmiTag(
	a->AtomicLoad(MachineType::Uint8(), backing_store, index_word)));

	a->Bind(&i16);
	a->Return(a->SmiTag(a->AtomicLoad(MachineType::Int16(), backing_store,
	a->WordShl(index_word, 1))));

	a->Bind(&u16);
	a->Return(a->SmiTag(a->AtomicLoad(MachineType::Uint16(), backing_store,
	a->WordShl(index_word, 1))));

	a->Bind(&i32);
	a->Return(a->ChangeInt32ToTagged(a->AtomicLoad(
	MachineType::Int32(), backing_store, a->WordShl(index_word, 2))));

	a->Bind(&u32);
	a->Return(a->ChangeUint32ToTagged(a->AtomicLoad(
	MachineType::Uint32(), backing_store, a->WordShl(index_word, 2))));

	// This shouldn't happen, we've already validated the type.
	a->Bind(&other);
	a->Return(a->Int32Constant(0));
	}

	void Builtins::Generate_AtomicsStore(CodeStubAssembler* a) {
	using namespace compiler;
	Node* array = a->Parameter(1);
	Node* index = a->Parameter(2);
	Node* value = a->Parameter(3);
	Node* context = a->Parameter(4 + 2);

	Node* instance_type;
	Node* backing_store;
	ValidateSharedTypedArray(a, array, context, &instance_type, &backing_store);

	Node* index_word32 = ConvertTaggedAtomicIndexToWord32(a, index, context);
	Node* array_length_word32 = a->TruncateTaggedToWord32(
	context, a->LoadObjectField(array, JSTypedArray::kLengthOffset));
	ValidateAtomicIndex(a, index_word32, array_length_word32, context);
	Node* index_word = a->ChangeUint32ToWord(index_word32);

	Node* value_integer = a->ToInteger(context, value);
	Node* value_word32 = a->TruncateTaggedToWord32(context, value_integer);

	CodeStubAssembler::Label u8(a), u16(a), u32(a), other(a);
	int32_t case_values[] = {
	FIXED_INT8_ARRAY_TYPE, FIXED_UINT8_ARRAY_TYPE, FIXED_INT16_ARRAY_TYPE,
	FIXED_UINT16_ARRAY_TYPE, FIXED_INT32_ARRAY_TYPE, FIXED_UINT32_ARRAY_TYPE,
	};
	CodeStubAssembler::Label* case_labels[] = {
	&u8, &u8, &u16, &u16, &u32, &u32,
	};
	a->Switch(instance_type, &other, case_values, case_labels,
	arraysize(case_labels));

	a->Bind(&u8);
	a->AtomicStore(MachineRepresentation::kWord8, backing_store, index_word,
	value_word32);
	a->Return(value_integer);

	a->Bind(&u16);
	a->AtomicStore(MachineRepresentation::kWord16, backing_store,
	a->WordShl(index_word, 1), value_word32);
	a->Return(value_integer);

	a->Bind(&u32);
	a->AtomicStore(MachineRepresentation::kWord32, backing_store,
	a->WordShl(index_word, 2), value_word32);
	a->Return(value_integer);

	// This shouldn't happen, we've already validated the type.
	a->Bind(&other);
	a->Return(a->Int32Constant(0));
	}

	} // namespace internal
	} // namespace v8