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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 #ifndef V8_CODE_STUB_ASSEMBLER_H_
6 #define V8_CODE_STUB_ASSEMBLER_H_
7 
8 #include "src/compiler/code-assembler.h"
9 #include "src/objects.h"
10 
11 namespace v8 {
12 namespace internal {
13 
14 class CallInterfaceDescriptor;
15 class StatsCounter;
16 class StubCache;
17 
18 // Provides JavaScript-specific "macro-assembler" functionality on top of the
19 // CodeAssembler. By factoring the JavaScript-isms out of the CodeAssembler,
20 // it's possible to add JavaScript-specific useful CodeAssembler "macros"
21 // without modifying files in the compiler directory (and requiring a review
22 // from a compiler directory OWNER).
23 class CodeStubAssembler : public compiler::CodeAssembler {
24  public:
25   // Create with CallStub linkage.
26   // |result_size| specifies the number of results returned by the stub.
27   // TODO(rmcilroy): move result_size to the CallInterfaceDescriptor.
28   CodeStubAssembler(Isolate* isolate, Zone* zone,
29                     const CallInterfaceDescriptor& descriptor,
30                     Code::Flags flags, const char* name,
31                     size_t result_size = 1);
32 
33   // Create with JSCall linkage.
34   CodeStubAssembler(Isolate* isolate, Zone* zone, int parameter_count,
35                     Code::Flags flags, const char* name);
36 
37   enum ParameterMode { INTEGER_PARAMETERS, SMI_PARAMETERS };
38 
39   compiler::Node* BooleanMapConstant();
40   compiler::Node* EmptyStringConstant();
41   compiler::Node* HeapNumberMapConstant();
42   compiler::Node* NoContextConstant();
43   compiler::Node* NullConstant();
44   compiler::Node* UndefinedConstant();
45   compiler::Node* TheHoleConstant();
46   compiler::Node* HashSeed();
47   compiler::Node* StaleRegisterConstant();
48 
49   // Float64 operations.
50   compiler::Node* Float64Ceil(compiler::Node* x);
51   compiler::Node* Float64Floor(compiler::Node* x);
52   compiler::Node* Float64Round(compiler::Node* x);
53   compiler::Node* Float64Trunc(compiler::Node* x);
54 
55   // Tag a Word as a Smi value.
56   compiler::Node* SmiTag(compiler::Node* value);
57   // Untag a Smi value as a Word.
58   compiler::Node* SmiUntag(compiler::Node* value);
59 
60   // Smi conversions.
61   compiler::Node* SmiToFloat64(compiler::Node* value);
SmiFromWord(compiler::Node * value)62   compiler::Node* SmiFromWord(compiler::Node* value) { return SmiTag(value); }
63   compiler::Node* SmiFromWord32(compiler::Node* value);
SmiToWord(compiler::Node * value)64   compiler::Node* SmiToWord(compiler::Node* value) { return SmiUntag(value); }
65   compiler::Node* SmiToWord32(compiler::Node* value);
66 
67   // Smi operations.
68   compiler::Node* SmiAdd(compiler::Node* a, compiler::Node* b);
69   compiler::Node* SmiAddWithOverflow(compiler::Node* a, compiler::Node* b);
70   compiler::Node* SmiSub(compiler::Node* a, compiler::Node* b);
71   compiler::Node* SmiSubWithOverflow(compiler::Node* a, compiler::Node* b);
72   compiler::Node* SmiEqual(compiler::Node* a, compiler::Node* b);
73   compiler::Node* SmiAboveOrEqual(compiler::Node* a, compiler::Node* b);
74   compiler::Node* SmiLessThan(compiler::Node* a, compiler::Node* b);
75   compiler::Node* SmiLessThanOrEqual(compiler::Node* a, compiler::Node* b);
76   compiler::Node* SmiMin(compiler::Node* a, compiler::Node* b);
77 
78   // Allocate an object of the given size.
79   compiler::Node* Allocate(compiler::Node* size, AllocationFlags flags = kNone);
80   compiler::Node* Allocate(int size, AllocationFlags flags = kNone);
81   compiler::Node* InnerAllocate(compiler::Node* previous, int offset);
82   compiler::Node* InnerAllocate(compiler::Node* previous,
83                                 compiler::Node* offset);
84 
85   void Assert(compiler::Node* condition);
86 
87   // Check a value for smi-ness
88   compiler::Node* WordIsSmi(compiler::Node* a);
89   // Check that the value is a positive smi.
90   compiler::Node* WordIsPositiveSmi(compiler::Node* a);
91 
BranchIfSmiLessThan(compiler::Node * a,compiler::Node * b,Label * if_true,Label * if_false)92   void BranchIfSmiLessThan(compiler::Node* a, compiler::Node* b, Label* if_true,
93                            Label* if_false) {
94     BranchIf(SmiLessThan(a, b), if_true, if_false);
95   }
96 
BranchIfSmiLessThanOrEqual(compiler::Node * a,compiler::Node * b,Label * if_true,Label * if_false)97   void BranchIfSmiLessThanOrEqual(compiler::Node* a, compiler::Node* b,
98                                   Label* if_true, Label* if_false) {
99     BranchIf(SmiLessThanOrEqual(a, b), if_true, if_false);
100   }
101 
BranchIfFloat64IsNaN(compiler::Node * value,Label * if_true,Label * if_false)102   void BranchIfFloat64IsNaN(compiler::Node* value, Label* if_true,
103                             Label* if_false) {
104     BranchIfFloat64Equal(value, value, if_false, if_true);
105   }
106 
107   // Load value from current frame by given offset in bytes.
108   compiler::Node* LoadFromFrame(int offset,
109                                 MachineType rep = MachineType::AnyTagged());
110   // Load value from current parent frame by given offset in bytes.
111   compiler::Node* LoadFromParentFrame(
112       int offset, MachineType rep = MachineType::AnyTagged());
113 
114   // Load an object pointer from a buffer that isn't in the heap.
115   compiler::Node* LoadBufferObject(compiler::Node* buffer, int offset,
116                                    MachineType rep = MachineType::AnyTagged());
117   // Load a field from an object on the heap.
118   compiler::Node* LoadObjectField(compiler::Node* object, int offset,
119                                   MachineType rep = MachineType::AnyTagged());
120   compiler::Node* LoadObjectField(compiler::Node* object,
121                                   compiler::Node* offset,
122                                   MachineType rep = MachineType::AnyTagged());
123 
124   // Load the floating point value of a HeapNumber.
125   compiler::Node* LoadHeapNumberValue(compiler::Node* object);
126   // Load the Map of an HeapObject.
127   compiler::Node* LoadMap(compiler::Node* object);
128   // Load the instance type of an HeapObject.
129   compiler::Node* LoadInstanceType(compiler::Node* object);
130   // Checks that given heap object has given instance type.
131   void AssertInstanceType(compiler::Node* object, InstanceType instance_type);
132   // Load the properties backing store of a JSObject.
133   compiler::Node* LoadProperties(compiler::Node* object);
134   // Load the elements backing store of a JSObject.
135   compiler::Node* LoadElements(compiler::Node* object);
136   // Load the length of a fixed array base instance.
137   compiler::Node* LoadFixedArrayBaseLength(compiler::Node* array);
138   // Load the bit field of a Map.
139   compiler::Node* LoadMapBitField(compiler::Node* map);
140   // Load bit field 2 of a map.
141   compiler::Node* LoadMapBitField2(compiler::Node* map);
142   // Load bit field 3 of a map.
143   compiler::Node* LoadMapBitField3(compiler::Node* map);
144   // Load the instance type of a map.
145   compiler::Node* LoadMapInstanceType(compiler::Node* map);
146   // Load the instance descriptors of a map.
147   compiler::Node* LoadMapDescriptors(compiler::Node* map);
148   // Load the prototype of a map.
149   compiler::Node* LoadMapPrototype(compiler::Node* map);
150   // Load the instance size of a Map.
151   compiler::Node* LoadMapInstanceSize(compiler::Node* map);
152   // Load the inobject properties count of a Map (valid only for JSObjects).
153   compiler::Node* LoadMapInobjectProperties(compiler::Node* map);
154 
155   // Load the hash field of a name.
156   compiler::Node* LoadNameHashField(compiler::Node* name);
157   // Load the hash value of a name. If {if_hash_not_computed} label
158   // is specified then it also checks if hash is actually computed.
159   compiler::Node* LoadNameHash(compiler::Node* name,
160                                Label* if_hash_not_computed = nullptr);
161 
162   // Load length field of a String object.
163   compiler::Node* LoadStringLength(compiler::Node* object);
164   // Load value field of a JSValue object.
165   compiler::Node* LoadJSValueValue(compiler::Node* object);
166   // Load value field of a WeakCell object.
167   compiler::Node* LoadWeakCellValue(compiler::Node* weak_cell,
168                                     Label* if_cleared = nullptr);
169 
170   compiler::Node* AllocateUninitializedFixedArray(compiler::Node* length);
171 
172   // Load an array element from a FixedArray.
173   compiler::Node* LoadFixedArrayElement(
174       compiler::Node* object, compiler::Node* int32_index,
175       int additional_offset = 0,
176       ParameterMode parameter_mode = INTEGER_PARAMETERS);
177   // Load an array element from a FixedDoubleArray.
178   compiler::Node* LoadFixedDoubleArrayElement(
179       compiler::Node* object, compiler::Node* int32_index,
180       MachineType machine_type, int additional_offset = 0,
181       ParameterMode parameter_mode = INTEGER_PARAMETERS);
182 
183   // Context manipulation
184   compiler::Node* LoadNativeContext(compiler::Node* context);
185 
186   compiler::Node* LoadJSArrayElementsMap(ElementsKind kind,
187                                          compiler::Node* native_context);
188 
189   // Store the floating point value of a HeapNumber.
190   compiler::Node* StoreHeapNumberValue(compiler::Node* object,
191                                        compiler::Node* value);
192   // Store a field to an object on the heap.
193   compiler::Node* StoreObjectField(
194       compiler::Node* object, int offset, compiler::Node* value);
195   compiler::Node* StoreObjectFieldNoWriteBarrier(
196       compiler::Node* object, int offset, compiler::Node* value,
197       MachineRepresentation rep = MachineRepresentation::kTagged);
198   // Store the Map of an HeapObject.
199   compiler::Node* StoreMapNoWriteBarrier(compiler::Node* object,
200                                          compiler::Node* map);
201   // Store an array element to a FixedArray.
202   compiler::Node* StoreFixedArrayElement(
203       compiler::Node* object, compiler::Node* index, compiler::Node* value,
204       WriteBarrierMode barrier_mode = UPDATE_WRITE_BARRIER,
205       ParameterMode parameter_mode = INTEGER_PARAMETERS);
206 
207   compiler::Node* StoreFixedDoubleArrayElement(
208       compiler::Node* object, compiler::Node* index, compiler::Node* value,
209       ParameterMode parameter_mode = INTEGER_PARAMETERS);
210 
211   // Allocate a HeapNumber without initializing its value.
212   compiler::Node* AllocateHeapNumber();
213   // Allocate a HeapNumber with a specific value.
214   compiler::Node* AllocateHeapNumberWithValue(compiler::Node* value);
215   // Allocate a SeqOneByteString with the given length.
216   compiler::Node* AllocateSeqOneByteString(int length);
217   compiler::Node* AllocateSeqOneByteString(compiler::Node* context,
218                                            compiler::Node* length);
219   // Allocate a SeqTwoByteString with the given length.
220   compiler::Node* AllocateSeqTwoByteString(int length);
221   compiler::Node* AllocateSeqTwoByteString(compiler::Node* context,
222                                            compiler::Node* length);
223   // Allocated an JSArray
224   compiler::Node* AllocateJSArray(ElementsKind kind, compiler::Node* array_map,
225                                   compiler::Node* capacity,
226                                   compiler::Node* length,
227                                   compiler::Node* allocation_site = nullptr,
228                                   ParameterMode mode = INTEGER_PARAMETERS);
229 
230   // Allocation site manipulation
231   void InitializeAllocationMemento(compiler::Node* base_allocation,
232                                    int base_allocation_size,
233                                    compiler::Node* allocation_site);
234 
235   compiler::Node* TruncateTaggedToFloat64(compiler::Node* context,
236                                           compiler::Node* value);
237   compiler::Node* TruncateTaggedToWord32(compiler::Node* context,
238                                          compiler::Node* value);
239   // Truncate the floating point value of a HeapNumber to an Int32.
240   compiler::Node* TruncateHeapNumberValueToWord32(compiler::Node* object);
241 
242   // Conversions.
243   compiler::Node* ChangeFloat64ToTagged(compiler::Node* value);
244   compiler::Node* ChangeInt32ToTagged(compiler::Node* value);
245   compiler::Node* ChangeUint32ToTagged(compiler::Node* value);
246 
247   // Type conversions.
248   // Throws a TypeError for {method_name} if {value} is not coercible to Object,
249   // or returns the {value} converted to a String otherwise.
250   compiler::Node* ToThisString(compiler::Node* context, compiler::Node* value,
251                                char const* method_name);
252 
253   // String helpers.
254   // Load a character from a String (might flatten a ConsString).
255   compiler::Node* StringCharCodeAt(compiler::Node* string,
256                                    compiler::Node* smi_index);
257   // Return the single character string with only {code}.
258   compiler::Node* StringFromCharCode(compiler::Node* code);
259 
260   // Returns a node that is true if the given bit is set in |word32|.
261   template <typename T>
BitFieldDecode(compiler::Node * word32)262   compiler::Node* BitFieldDecode(compiler::Node* word32) {
263     return BitFieldDecode(word32, T::kShift, T::kMask);
264   }
265 
266   compiler::Node* BitFieldDecode(compiler::Node* word32, uint32_t shift,
267                                  uint32_t mask);
268 
269   void SetCounter(StatsCounter* counter, int value);
270   void IncrementCounter(StatsCounter* counter, int delta);
271   void DecrementCounter(StatsCounter* counter, int delta);
272 
273   // Various building blocks for stubs doing property lookups.
274   void TryToName(compiler::Node* key, Label* if_keyisindex, Variable* var_index,
275                  Label* if_keyisunique, Label* if_bailout);
276 
277   // Calculates array index for given dictionary entry and entry field.
278   // See Dictionary::EntryToIndex().
279   template <typename Dictionary>
280   compiler::Node* EntryToIndex(compiler::Node* entry, int field_index);
281   template <typename Dictionary>
EntryToIndex(compiler::Node * entry)282   compiler::Node* EntryToIndex(compiler::Node* entry) {
283     return EntryToIndex<Dictionary>(entry, Dictionary::kEntryKeyIndex);
284   }
285 
286   // Looks up an entry in a NameDictionaryBase successor. If the entry is found
287   // control goes to {if_found} and {var_name_index} contains an index of the
288   // key field of the entry found. If the key is not found control goes to
289   // {if_not_found}.
290   static const int kInlinedDictionaryProbes = 4;
291   template <typename Dictionary>
292   void NameDictionaryLookup(compiler::Node* dictionary,
293                             compiler::Node* unique_name, Label* if_found,
294                             Variable* var_name_index, Label* if_not_found,
295                             int inlined_probes = kInlinedDictionaryProbes);
296 
297   compiler::Node* ComputeIntegerHash(compiler::Node* key, compiler::Node* seed);
298 
299   template <typename Dictionary>
300   void NumberDictionaryLookup(compiler::Node* dictionary, compiler::Node* key,
301                               Label* if_found, Variable* var_entry,
302                               Label* if_not_found);
303 
304   // Tries to check if {object} has own {unique_name} property.
305   void TryHasOwnProperty(compiler::Node* object, compiler::Node* map,
306                          compiler::Node* instance_type,
307                          compiler::Node* unique_name, Label* if_found,
308                          Label* if_not_found, Label* if_bailout);
309 
310   // Tries to get {object}'s own {unique_name} property value. If the property
311   // is an accessor then it also calls a getter. If the property is a double
312   // field it re-wraps value in an immutable heap number.
313   void TryGetOwnProperty(compiler::Node* context, compiler::Node* receiver,
314                          compiler::Node* object, compiler::Node* map,
315                          compiler::Node* instance_type,
316                          compiler::Node* unique_name, Label* if_found,
317                          Variable* var_value, Label* if_not_found,
318                          Label* if_bailout);
319 
320   void LoadPropertyFromFastObject(compiler::Node* object, compiler::Node* map,
321                                   compiler::Node* descriptors,
322                                   compiler::Node* name_index,
323                                   Variable* var_details, Variable* var_value);
324 
325   void LoadPropertyFromNameDictionary(compiler::Node* dictionary,
326                                       compiler::Node* entry,
327                                       Variable* var_details,
328                                       Variable* var_value);
329 
330   void LoadPropertyFromGlobalDictionary(compiler::Node* dictionary,
331                                         compiler::Node* entry,
332                                         Variable* var_details,
333                                         Variable* var_value, Label* if_deleted);
334 
335   // Generic property lookup generator. If the {object} is fast and
336   // {unique_name} property is found then the control goes to {if_found_fast}
337   // label and {var_meta_storage} and {var_name_index} will contain
338   // DescriptorArray and an index of the descriptor's name respectively.
339   // If the {object} is slow or global then the control goes to {if_found_dict}
340   // or {if_found_global} and the {var_meta_storage} and {var_name_index} will
341   // contain a dictionary and an index of the key field of the found entry.
342   // If property is not found or given lookup is not supported then
343   // the control goes to {if_not_found} or {if_bailout} respectively.
344   //
345   // Note: this code does not check if the global dictionary points to deleted
346   // entry! This has to be done by the caller.
347   void TryLookupProperty(compiler::Node* object, compiler::Node* map,
348                          compiler::Node* instance_type,
349                          compiler::Node* unique_name, Label* if_found_fast,
350                          Label* if_found_dict, Label* if_found_global,
351                          Variable* var_meta_storage, Variable* var_name_index,
352                          Label* if_not_found, Label* if_bailout);
353 
354   void TryLookupElement(compiler::Node* object, compiler::Node* map,
355                         compiler::Node* instance_type, compiler::Node* index,
356                         Label* if_found, Label* if_not_found,
357                         Label* if_bailout);
358 
359   // Instanceof helpers.
360   // ES6 section 7.3.19 OrdinaryHasInstance (C, O)
361   compiler::Node* OrdinaryHasInstance(compiler::Node* context,
362                                       compiler::Node* callable,
363                                       compiler::Node* object);
364 
365   // LoadIC helpers.
366   struct LoadICParameters {
LoadICParametersLoadICParameters367     LoadICParameters(compiler::Node* context, compiler::Node* receiver,
368                      compiler::Node* name, compiler::Node* slot,
369                      compiler::Node* vector)
370         : context(context),
371           receiver(receiver),
372           name(name),
373           slot(slot),
374           vector(vector) {}
375 
376     compiler::Node* context;
377     compiler::Node* receiver;
378     compiler::Node* name;
379     compiler::Node* slot;
380     compiler::Node* vector;
381   };
382 
383   // Load type feedback vector from the stub caller's frame.
384   compiler::Node* LoadTypeFeedbackVectorForStub();
385 
386   compiler::Node* LoadReceiverMap(compiler::Node* receiver);
387 
388   // Checks monomorphic case. Returns {feedback} entry of the vector.
389   compiler::Node* TryMonomorphicCase(const LoadICParameters* p,
390                                      compiler::Node* receiver_map,
391                                      Label* if_handler, Variable* var_handler,
392                                      Label* if_miss);
393   void HandlePolymorphicCase(const LoadICParameters* p,
394                              compiler::Node* receiver_map,
395                              compiler::Node* feedback, Label* if_handler,
396                              Variable* var_handler, Label* if_miss,
397                              int unroll_count);
398 
399   compiler::Node* StubCachePrimaryOffset(compiler::Node* name,
400                                          Code::Flags flags,
401                                          compiler::Node* map);
402 
403   compiler::Node* StubCacheSecondaryOffset(compiler::Node* name,
404                                            Code::Flags flags,
405                                            compiler::Node* seed);
406 
407   // This enum is used here as a replacement for StubCache::Table to avoid
408   // including stub cache header.
409   enum StubCacheTable : int;
410 
411   void TryProbeStubCacheTable(StubCache* stub_cache, StubCacheTable table_id,
412                               compiler::Node* entry_offset,
413                               compiler::Node* name, Code::Flags flags,
414                               compiler::Node* map, Label* if_handler,
415                               Variable* var_handler, Label* if_miss);
416 
417   void TryProbeStubCache(StubCache* stub_cache, Code::Flags flags,
418                          compiler::Node* receiver, compiler::Node* name,
419                          Label* if_handler, Variable* var_handler,
420                          Label* if_miss);
421 
422   void LoadIC(const LoadICParameters* p);
423   void LoadGlobalIC(const LoadICParameters* p);
424 
425  private:
426   compiler::Node* ElementOffsetFromIndex(compiler::Node* index,
427                                          ElementsKind kind, ParameterMode mode,
428                                          int base_size = 0);
429 
430   compiler::Node* AllocateRawAligned(compiler::Node* size_in_bytes,
431                                      AllocationFlags flags,
432                                      compiler::Node* top_address,
433                                      compiler::Node* limit_address);
434   compiler::Node* AllocateRawUnaligned(compiler::Node* size_in_bytes,
435                                        AllocationFlags flags,
436                                        compiler::Node* top_adddress,
437                                        compiler::Node* limit_address);
438 
439   static const int kElementLoopUnrollThreshold = 8;
440 };
441 
442 }  // namespace internal
443 }  // namespace v8
444 #endif  // V8_CODE_STUB_ASSEMBLER_H_
445