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1 // Copyright 2016 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include "src/builtins/builtins-utils.h"
6 #include "src/builtins/builtins.h"
7 #include "src/code-factory.h"
8 #include "src/code-stub-assembler.h"
9 
10 namespace v8 {
11 namespace internal {
12 
13 // ES7 sharedmem 6.3.4.1 get SharedArrayBuffer.prototype.byteLength
BUILTIN(SharedArrayBufferPrototypeGetByteLength)14 BUILTIN(SharedArrayBufferPrototypeGetByteLength) {
15   HandleScope scope(isolate);
16   CHECK_RECEIVER(JSArrayBuffer, array_buffer,
17                  "get SharedArrayBuffer.prototype.byteLength");
18   if (!array_buffer->is_shared()) {
19     THROW_NEW_ERROR_RETURN_FAILURE(
20         isolate, NewTypeError(MessageTemplate::kIncompatibleMethodReceiver,
21                               isolate->factory()->NewStringFromAsciiChecked(
22                                   "get SharedArrayBuffer.prototype.byteLength"),
23                               args.receiver()));
24   }
25   return array_buffer->byte_length();
26 }
27 
28 namespace {
29 
ValidateSharedTypedArray(CodeStubAssembler * a,compiler::Node * tagged,compiler::Node * context,compiler::Node ** out_instance_type,compiler::Node ** out_backing_store)30 void ValidateSharedTypedArray(CodeStubAssembler* a, compiler::Node* tagged,
31                               compiler::Node* context,
32                               compiler::Node** out_instance_type,
33                               compiler::Node** out_backing_store) {
34   using compiler::Node;
35   CodeStubAssembler::Label is_smi(a), not_smi(a), is_typed_array(a),
36       not_typed_array(a), is_shared(a), not_shared(a), is_float_or_clamped(a),
37       not_float_or_clamped(a), invalid(a);
38 
39   // Fail if it is not a heap object.
40   a->Branch(a->TaggedIsSmi(tagged), &is_smi, &not_smi);
41   a->Bind(&is_smi);
42   a->Goto(&invalid);
43 
44   // Fail if the array's instance type is not JSTypedArray.
45   a->Bind(&not_smi);
46   a->Branch(a->Word32Equal(a->LoadInstanceType(tagged),
47                            a->Int32Constant(JS_TYPED_ARRAY_TYPE)),
48             &is_typed_array, &not_typed_array);
49   a->Bind(&not_typed_array);
50   a->Goto(&invalid);
51 
52   // Fail if the array's JSArrayBuffer is not shared.
53   a->Bind(&is_typed_array);
54   Node* array_buffer = a->LoadObjectField(tagged, JSTypedArray::kBufferOffset);
55   Node* is_buffer_shared =
56       a->IsSetWord32<JSArrayBuffer::IsShared>(a->LoadObjectField(
57           array_buffer, JSArrayBuffer::kBitFieldOffset, MachineType::Uint32()));
58   a->Branch(is_buffer_shared, &is_shared, &not_shared);
59   a->Bind(&not_shared);
60   a->Goto(&invalid);
61 
62   // Fail if the array's element type is float32, float64 or clamped.
63   a->Bind(&is_shared);
64   Node* elements_instance_type = a->LoadInstanceType(
65       a->LoadObjectField(tagged, JSObject::kElementsOffset));
66   STATIC_ASSERT(FIXED_INT8_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
67   STATIC_ASSERT(FIXED_INT16_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
68   STATIC_ASSERT(FIXED_INT32_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
69   STATIC_ASSERT(FIXED_UINT8_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
70   STATIC_ASSERT(FIXED_UINT16_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
71   STATIC_ASSERT(FIXED_UINT32_ARRAY_TYPE < FIXED_FLOAT32_ARRAY_TYPE);
72   a->Branch(a->Int32LessThan(elements_instance_type,
73                              a->Int32Constant(FIXED_FLOAT32_ARRAY_TYPE)),
74             &not_float_or_clamped, &is_float_or_clamped);
75   a->Bind(&is_float_or_clamped);
76   a->Goto(&invalid);
77 
78   a->Bind(&invalid);
79   a->CallRuntime(Runtime::kThrowNotIntegerSharedTypedArrayError, context,
80                  tagged);
81   a->Unreachable();
82 
83   a->Bind(&not_float_or_clamped);
84   *out_instance_type = elements_instance_type;
85 
86   Node* backing_store =
87       a->LoadObjectField(array_buffer, JSArrayBuffer::kBackingStoreOffset);
88   Node* byte_offset = a->ChangeUint32ToWord(a->TruncateTaggedToWord32(
89       context,
90       a->LoadObjectField(tagged, JSArrayBufferView::kByteOffsetOffset)));
91   *out_backing_store =
92       a->IntPtrAdd(a->BitcastTaggedToWord(backing_store), byte_offset);
93 }
94 
95 // https://tc39.github.io/ecmascript_sharedmem/shmem.html#Atomics.ValidateAtomicAccess
ConvertTaggedAtomicIndexToWord32(CodeStubAssembler * a,compiler::Node * tagged,compiler::Node * context)96 compiler::Node* ConvertTaggedAtomicIndexToWord32(CodeStubAssembler* a,
97                                                  compiler::Node* tagged,
98                                                  compiler::Node* context) {
99   using compiler::Node;
100   CodeStubAssembler::Variable var_result(a, MachineRepresentation::kWord32);
101 
102   Callable to_number = CodeFactory::ToNumber(a->isolate());
103   Node* number_index = a->CallStub(to_number, context, tagged);
104   CodeStubAssembler::Label done(a, &var_result);
105 
106   CodeStubAssembler::Label if_numberissmi(a), if_numberisnotsmi(a);
107   a->Branch(a->TaggedIsSmi(number_index), &if_numberissmi, &if_numberisnotsmi);
108 
109   a->Bind(&if_numberissmi);
110   {
111     var_result.Bind(a->SmiToWord32(number_index));
112     a->Goto(&done);
113   }
114 
115   a->Bind(&if_numberisnotsmi);
116   {
117     Node* number_index_value = a->LoadHeapNumberValue(number_index);
118     Node* access_index = a->TruncateFloat64ToWord32(number_index_value);
119     Node* test_index = a->ChangeInt32ToFloat64(access_index);
120 
121     CodeStubAssembler::Label if_indexesareequal(a), if_indexesarenotequal(a);
122     a->Branch(a->Float64Equal(number_index_value, test_index),
123               &if_indexesareequal, &if_indexesarenotequal);
124 
125     a->Bind(&if_indexesareequal);
126     {
127       var_result.Bind(access_index);
128       a->Goto(&done);
129     }
130 
131     a->Bind(&if_indexesarenotequal);
132     a->CallRuntime(Runtime::kThrowInvalidAtomicAccessIndexError, context);
133     a->Unreachable();
134   }
135 
136   a->Bind(&done);
137   return var_result.value();
138 }
139 
ValidateAtomicIndex(CodeStubAssembler * a,compiler::Node * index_word,compiler::Node * array_length_word,compiler::Node * context)140 void ValidateAtomicIndex(CodeStubAssembler* a, compiler::Node* index_word,
141                          compiler::Node* array_length_word,
142                          compiler::Node* context) {
143   using compiler::Node;
144   // Check if the index is in bounds. If not, throw RangeError.
145   CodeStubAssembler::Label if_inbounds(a), if_notinbounds(a);
146   // TODO(jkummerow): Use unsigned comparison instead of "i<0 || i>length".
147   a->Branch(
148       a->Word32Or(a->Int32LessThan(index_word, a->Int32Constant(0)),
149                   a->Int32GreaterThanOrEqual(index_word, array_length_word)),
150       &if_notinbounds, &if_inbounds);
151   a->Bind(&if_notinbounds);
152   a->CallRuntime(Runtime::kThrowInvalidAtomicAccessIndexError, context);
153   a->Unreachable();
154   a->Bind(&if_inbounds);
155 }
156 
157 }  // anonymous namespace
158 
Generate_AtomicsLoad(compiler::CodeAssemblerState * state)159 void Builtins::Generate_AtomicsLoad(compiler::CodeAssemblerState* state) {
160   using compiler::Node;
161   CodeStubAssembler a(state);
162   Node* array = a.Parameter(1);
163   Node* index = a.Parameter(2);
164   Node* context = a.Parameter(3 + 2);
165 
166   Node* instance_type;
167   Node* backing_store;
168   ValidateSharedTypedArray(&a, array, context, &instance_type, &backing_store);
169 
170   Node* index_word32 = ConvertTaggedAtomicIndexToWord32(&a, index, context);
171   Node* array_length_word32 = a.TruncateTaggedToWord32(
172       context, a.LoadObjectField(array, JSTypedArray::kLengthOffset));
173   ValidateAtomicIndex(&a, index_word32, array_length_word32, context);
174   Node* index_word = a.ChangeUint32ToWord(index_word32);
175 
176   CodeStubAssembler::Label i8(&a), u8(&a), i16(&a), u16(&a), i32(&a), u32(&a),
177       other(&a);
178   int32_t case_values[] = {
179       FIXED_INT8_ARRAY_TYPE,   FIXED_UINT8_ARRAY_TYPE, FIXED_INT16_ARRAY_TYPE,
180       FIXED_UINT16_ARRAY_TYPE, FIXED_INT32_ARRAY_TYPE, FIXED_UINT32_ARRAY_TYPE,
181   };
182   CodeStubAssembler::Label* case_labels[] = {
183       &i8, &u8, &i16, &u16, &i32, &u32,
184   };
185   a.Switch(instance_type, &other, case_values, case_labels,
186            arraysize(case_labels));
187 
188   a.Bind(&i8);
189   a.Return(a.SmiFromWord32(
190       a.AtomicLoad(MachineType::Int8(), backing_store, index_word)));
191 
192   a.Bind(&u8);
193   a.Return(a.SmiFromWord32(
194       a.AtomicLoad(MachineType::Uint8(), backing_store, index_word)));
195 
196   a.Bind(&i16);
197   a.Return(a.SmiFromWord32(a.AtomicLoad(MachineType::Int16(), backing_store,
198                                         a.WordShl(index_word, 1))));
199 
200   a.Bind(&u16);
201   a.Return(a.SmiFromWord32(a.AtomicLoad(MachineType::Uint16(), backing_store,
202                                         a.WordShl(index_word, 1))));
203 
204   a.Bind(&i32);
205   a.Return(a.ChangeInt32ToTagged(a.AtomicLoad(
206       MachineType::Int32(), backing_store, a.WordShl(index_word, 2))));
207 
208   a.Bind(&u32);
209   a.Return(a.ChangeUint32ToTagged(a.AtomicLoad(
210       MachineType::Uint32(), backing_store, a.WordShl(index_word, 2))));
211 
212   // This shouldn't happen, we've already validated the type.
213   a.Bind(&other);
214   a.Return(a.SmiConstant(0));
215 }
216 
Generate_AtomicsStore(compiler::CodeAssemblerState * state)217 void Builtins::Generate_AtomicsStore(compiler::CodeAssemblerState* state) {
218   using compiler::Node;
219   CodeStubAssembler a(state);
220   Node* array = a.Parameter(1);
221   Node* index = a.Parameter(2);
222   Node* value = a.Parameter(3);
223   Node* context = a.Parameter(4 + 2);
224 
225   Node* instance_type;
226   Node* backing_store;
227   ValidateSharedTypedArray(&a, array, context, &instance_type, &backing_store);
228 
229   Node* index_word32 = ConvertTaggedAtomicIndexToWord32(&a, index, context);
230   Node* array_length_word32 = a.TruncateTaggedToWord32(
231       context, a.LoadObjectField(array, JSTypedArray::kLengthOffset));
232   ValidateAtomicIndex(&a, index_word32, array_length_word32, context);
233   Node* index_word = a.ChangeUint32ToWord(index_word32);
234 
235   Node* value_integer = a.ToInteger(context, value);
236   Node* value_word32 = a.TruncateTaggedToWord32(context, value_integer);
237 
238   CodeStubAssembler::Label u8(&a), u16(&a), u32(&a), other(&a);
239   int32_t case_values[] = {
240       FIXED_INT8_ARRAY_TYPE,   FIXED_UINT8_ARRAY_TYPE, FIXED_INT16_ARRAY_TYPE,
241       FIXED_UINT16_ARRAY_TYPE, FIXED_INT32_ARRAY_TYPE, FIXED_UINT32_ARRAY_TYPE,
242   };
243   CodeStubAssembler::Label* case_labels[] = {
244       &u8, &u8, &u16, &u16, &u32, &u32,
245   };
246   a.Switch(instance_type, &other, case_values, case_labels,
247            arraysize(case_labels));
248 
249   a.Bind(&u8);
250   a.AtomicStore(MachineRepresentation::kWord8, backing_store, index_word,
251                 value_word32);
252   a.Return(value_integer);
253 
254   a.Bind(&u16);
255   a.AtomicStore(MachineRepresentation::kWord16, backing_store,
256                 a.WordShl(index_word, 1), value_word32);
257   a.Return(value_integer);
258 
259   a.Bind(&u32);
260   a.AtomicStore(MachineRepresentation::kWord32, backing_store,
261                 a.WordShl(index_word, 2), value_word32);
262   a.Return(value_integer);
263 
264   // This shouldn't happen, we've already validated the type.
265   a.Bind(&other);
266   a.Return(a.SmiConstant(0));
267 }
268 
269 }  // namespace internal
270 }  // namespace v8
271