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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.h"
6 #include "src/builtins/builtins-utils.h"
7 
8 #include "src/code-factory.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 namespace compiler;
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->WordEqual(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->Return(a->UndefinedConstant());
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 = a->IntPtrAdd(backing_store, byte_offset);
92 }
93 
94 // https://tc39.github.io/ecmascript_sharedmem/shmem.html#Atomics.ValidateAtomicAccess
ConvertTaggedAtomicIndexToWord32(CodeStubAssembler * a,compiler::Node * tagged,compiler::Node * context)95 compiler::Node* ConvertTaggedAtomicIndexToWord32(CodeStubAssembler* a,
96                                                  compiler::Node* tagged,
97                                                  compiler::Node* context) {
98   using namespace compiler;
99   CodeStubAssembler::Variable var_result(a, MachineRepresentation::kWord32);
100 
101   Callable to_number = CodeFactory::ToNumber(a->isolate());
102   Node* number_index = a->CallStub(to_number, context, tagged);
103   CodeStubAssembler::Label done(a, &var_result);
104 
105   CodeStubAssembler::Label if_numberissmi(a), if_numberisnotsmi(a);
106   a->Branch(a->TaggedIsSmi(number_index), &if_numberissmi, &if_numberisnotsmi);
107 
108   a->Bind(&if_numberissmi);
109   {
110     var_result.Bind(a->SmiToWord32(number_index));
111     a->Goto(&done);
112   }
113 
114   a->Bind(&if_numberisnotsmi);
115   {
116     Node* number_index_value = a->LoadHeapNumberValue(number_index);
117     Node* access_index = a->TruncateFloat64ToWord32(number_index_value);
118     Node* test_index = a->ChangeInt32ToFloat64(access_index);
119 
120     CodeStubAssembler::Label if_indexesareequal(a), if_indexesarenotequal(a);
121     a->Branch(a->Float64Equal(number_index_value, test_index),
122               &if_indexesareequal, &if_indexesarenotequal);
123 
124     a->Bind(&if_indexesareequal);
125     {
126       var_result.Bind(access_index);
127       a->Goto(&done);
128     }
129 
130     a->Bind(&if_indexesarenotequal);
131     a->Return(
132         a->CallRuntime(Runtime::kThrowInvalidAtomicAccessIndexError, context));
133   }
134 
135   a->Bind(&done);
136   return var_result.value();
137 }
138 
ValidateAtomicIndex(CodeStubAssembler * a,compiler::Node * index_word,compiler::Node * array_length_word,compiler::Node * context)139 void ValidateAtomicIndex(CodeStubAssembler* a, compiler::Node* index_word,
140                          compiler::Node* array_length_word,
141                          compiler::Node* context) {
142   using namespace compiler;
143   // Check if the index is in bounds. If not, throw RangeError.
144   CodeStubAssembler::Label if_inbounds(a), if_notinbounds(a);
145   // TODO(jkummerow): Use unsigned comparison instead of "i<0 || i>length".
146   a->Branch(
147       a->WordOr(a->Int32LessThan(index_word, a->Int32Constant(0)),
148                 a->Int32GreaterThanOrEqual(index_word, array_length_word)),
149       &if_notinbounds, &if_inbounds);
150   a->Bind(&if_notinbounds);
151   a->Return(
152       a->CallRuntime(Runtime::kThrowInvalidAtomicAccessIndexError, context));
153   a->Bind(&if_inbounds);
154 }
155 
156 }  // anonymous namespace
157 
Generate_AtomicsLoad(CodeStubAssembler * a)158 void Builtins::Generate_AtomicsLoad(CodeStubAssembler* a) {
159   using namespace compiler;
160   Node* array = a->Parameter(1);
161   Node* index = a->Parameter(2);
162   Node* context = a->Parameter(3 + 2);
163 
164   Node* instance_type;
165   Node* backing_store;
166   ValidateSharedTypedArray(a, array, context, &instance_type, &backing_store);
167 
168   Node* index_word32 = ConvertTaggedAtomicIndexToWord32(a, index, context);
169   Node* array_length_word32 = a->TruncateTaggedToWord32(
170       context, a->LoadObjectField(array, JSTypedArray::kLengthOffset));
171   ValidateAtomicIndex(a, index_word32, array_length_word32, context);
172   Node* index_word = a->ChangeUint32ToWord(index_word32);
173 
174   CodeStubAssembler::Label i8(a), u8(a), i16(a), u16(a), i32(a), u32(a),
175       other(a);
176   int32_t case_values[] = {
177       FIXED_INT8_ARRAY_TYPE,   FIXED_UINT8_ARRAY_TYPE, FIXED_INT16_ARRAY_TYPE,
178       FIXED_UINT16_ARRAY_TYPE, FIXED_INT32_ARRAY_TYPE, FIXED_UINT32_ARRAY_TYPE,
179   };
180   CodeStubAssembler::Label* case_labels[] = {
181       &i8, &u8, &i16, &u16, &i32, &u32,
182   };
183   a->Switch(instance_type, &other, case_values, case_labels,
184             arraysize(case_labels));
185 
186   a->Bind(&i8);
187   a->Return(
188       a->SmiTag(a->AtomicLoad(MachineType::Int8(), backing_store, index_word)));
189 
190   a->Bind(&u8);
191   a->Return(a->SmiTag(
192       a->AtomicLoad(MachineType::Uint8(), backing_store, index_word)));
193 
194   a->Bind(&i16);
195   a->Return(a->SmiTag(a->AtomicLoad(MachineType::Int16(), backing_store,
196                                     a->WordShl(index_word, 1))));
197 
198   a->Bind(&u16);
199   a->Return(a->SmiTag(a->AtomicLoad(MachineType::Uint16(), backing_store,
200                                     a->WordShl(index_word, 1))));
201 
202   a->Bind(&i32);
203   a->Return(a->ChangeInt32ToTagged(a->AtomicLoad(
204       MachineType::Int32(), backing_store, a->WordShl(index_word, 2))));
205 
206   a->Bind(&u32);
207   a->Return(a->ChangeUint32ToTagged(a->AtomicLoad(
208       MachineType::Uint32(), backing_store, a->WordShl(index_word, 2))));
209 
210   // This shouldn't happen, we've already validated the type.
211   a->Bind(&other);
212   a->Return(a->Int32Constant(0));
213 }
214 
Generate_AtomicsStore(CodeStubAssembler * a)215 void Builtins::Generate_AtomicsStore(CodeStubAssembler* a) {
216   using namespace compiler;
217   Node* array = a->Parameter(1);
218   Node* index = a->Parameter(2);
219   Node* value = a->Parameter(3);
220   Node* context = a->Parameter(4 + 2);
221 
222   Node* instance_type;
223   Node* backing_store;
224   ValidateSharedTypedArray(a, array, context, &instance_type, &backing_store);
225 
226   Node* index_word32 = ConvertTaggedAtomicIndexToWord32(a, index, context);
227   Node* array_length_word32 = a->TruncateTaggedToWord32(
228       context, a->LoadObjectField(array, JSTypedArray::kLengthOffset));
229   ValidateAtomicIndex(a, index_word32, array_length_word32, context);
230   Node* index_word = a->ChangeUint32ToWord(index_word32);
231 
232   Node* value_integer = a->ToInteger(context, value);
233   Node* value_word32 = a->TruncateTaggedToWord32(context, value_integer);
234 
235   CodeStubAssembler::Label u8(a), u16(a), u32(a), other(a);
236   int32_t case_values[] = {
237       FIXED_INT8_ARRAY_TYPE,   FIXED_UINT8_ARRAY_TYPE, FIXED_INT16_ARRAY_TYPE,
238       FIXED_UINT16_ARRAY_TYPE, FIXED_INT32_ARRAY_TYPE, FIXED_UINT32_ARRAY_TYPE,
239   };
240   CodeStubAssembler::Label* case_labels[] = {
241       &u8, &u8, &u16, &u16, &u32, &u32,
242   };
243   a->Switch(instance_type, &other, case_values, case_labels,
244             arraysize(case_labels));
245 
246   a->Bind(&u8);
247   a->AtomicStore(MachineRepresentation::kWord8, backing_store, index_word,
248                  value_word32);
249   a->Return(value_integer);
250 
251   a->Bind(&u16);
252   a->AtomicStore(MachineRepresentation::kWord16, backing_store,
253                  a->WordShl(index_word, 1), value_word32);
254   a->Return(value_integer);
255 
256   a->Bind(&u32);
257   a->AtomicStore(MachineRepresentation::kWord32, backing_store,
258                  a->WordShl(index_word, 2), value_word32);
259   a->Return(value_integer);
260 
261   // This shouldn't happen, we've already validated the type.
262   a->Bind(&other);
263   a->Return(a->Int32Constant(0));
264 }
265 
266 }  // namespace internal
267 }  // namespace v8
268