1 // Copyright 2013 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_ARM64_LITHIUM_CODEGEN_ARM64_H_
6 #define V8_ARM64_LITHIUM_CODEGEN_ARM64_H_
7 
8 #include "src/arm64/lithium-arm64.h"
9 
10 #include "src/arm64/lithium-gap-resolver-arm64.h"
11 #include "src/deoptimizer.h"
12 #include "src/lithium-codegen.h"
13 #include "src/safepoint-table.h"
14 #include "src/scopes.h"
15 #include "src/utils.h"
16 
17 namespace v8 {
18 namespace internal {
19 
20 // Forward declarations.
21 class LDeferredCode;
22 class SafepointGenerator;
23 class BranchGenerator;
24 
25 class LCodeGen: public LCodeGenBase {
26  public:
LCodeGen(LChunk * chunk,MacroAssembler * assembler,CompilationInfo * info)27   LCodeGen(LChunk* chunk, MacroAssembler* assembler, CompilationInfo* info)
28       : LCodeGenBase(chunk, assembler, info),
29         deoptimizations_(4, info->zone()),
30         jump_table_(4, info->zone()),
31         deoptimization_literals_(8, info->zone()),
32         inlined_function_count_(0),
33         scope_(info->scope()),
34         translations_(info->zone()),
35         deferred_(8, info->zone()),
36         osr_pc_offset_(-1),
37         frame_is_built_(false),
38         safepoints_(info->zone()),
39         resolver_(this),
40         expected_safepoint_kind_(Safepoint::kSimple),
41         after_push_argument_(false),
42         inlined_arguments_(false) {
43     PopulateDeoptimizationLiteralsWithInlinedFunctions();
44   }
45 
~LCodeGen()46   ~LCodeGen() {
47     DCHECK(!after_push_argument_ || inlined_arguments_);
48   }
49 
50   // Simple accessors.
scope()51   Scope* scope() const { return scope_; }
52 
LookupDestination(int block_id)53   int LookupDestination(int block_id) const {
54     return chunk()->LookupDestination(block_id);
55   }
56 
IsNextEmittedBlock(int block_id)57   bool IsNextEmittedBlock(int block_id) const {
58     return LookupDestination(block_id) == GetNextEmittedBlock();
59   }
60 
NeedsEagerFrame()61   bool NeedsEagerFrame() const {
62     return GetStackSlotCount() > 0 ||
63         info()->is_non_deferred_calling() ||
64         !info()->IsStub() ||
65         info()->requires_frame();
66   }
NeedsDeferredFrame()67   bool NeedsDeferredFrame() const {
68     return !NeedsEagerFrame() && info()->is_deferred_calling();
69   }
70 
GetLinkRegisterState()71   LinkRegisterStatus GetLinkRegisterState() const {
72     return frame_is_built_ ? kLRHasBeenSaved : kLRHasNotBeenSaved;
73   }
74 
75   // Try to generate code for the entire chunk, but it may fail if the
76   // chunk contains constructs we cannot handle. Returns true if the
77   // code generation attempt succeeded.
78   bool GenerateCode();
79 
80   // Finish the code by setting stack height, safepoint, and bailout
81   // information on it.
82   void FinishCode(Handle<Code> code);
83 
84   enum IntegerSignedness { SIGNED_INT32, UNSIGNED_INT32 };
85   // Support for converting LOperands to assembler types.
86   Register ToRegister(LOperand* op) const;
87   Register ToRegister32(LOperand* op) const;
88   Operand ToOperand(LOperand* op);
89   Operand ToOperand32(LOperand* op);
90   enum StackMode { kMustUseFramePointer, kCanUseStackPointer };
91   MemOperand ToMemOperand(LOperand* op,
92                           StackMode stack_mode = kCanUseStackPointer) const;
93   Handle<Object> ToHandle(LConstantOperand* op) const;
94 
95   template <class LI>
96   Operand ToShiftedRightOperand32(LOperand* right, LI* shift_info);
97 
JSShiftAmountFromLConstant(LOperand * constant)98   int JSShiftAmountFromLConstant(LOperand* constant) {
99     return ToInteger32(LConstantOperand::cast(constant)) & 0x1f;
100   }
101 
102   // TODO(jbramley): Examine these helpers and check that they make sense.
103   // IsInteger32Constant returns true for smi constants, for example.
104   bool IsInteger32Constant(LConstantOperand* op) const;
105   bool IsSmi(LConstantOperand* op) const;
106 
107   int32_t ToInteger32(LConstantOperand* op) const;
108   Smi* ToSmi(LConstantOperand* op) const;
109   double ToDouble(LConstantOperand* op) const;
110   DoubleRegister ToDoubleRegister(LOperand* op) const;
111 
112   // Declare methods that deal with the individual node types.
113 #define DECLARE_DO(type) void Do##type(L##type* node);
LITHIUM_CONCRETE_INSTRUCTION_LIST(DECLARE_DO)114   LITHIUM_CONCRETE_INSTRUCTION_LIST(DECLARE_DO)
115 #undef DECLARE_DO
116 
117  private:
118   // Return a double scratch register which can be used locally
119   // when generating code for a lithium instruction.
120   DoubleRegister double_scratch() { return crankshaft_fp_scratch; }
121 
122   // Deferred code support.
123   void DoDeferredNumberTagD(LNumberTagD* instr);
124   void DoDeferredStackCheck(LStackCheck* instr);
125   void DoDeferredStringCharCodeAt(LStringCharCodeAt* instr);
126   void DoDeferredStringCharFromCode(LStringCharFromCode* instr);
127   void DoDeferredMathAbsTagged(LMathAbsTagged* instr,
128                                Label* exit,
129                                Label* allocation_entry);
130 
131   void DoDeferredNumberTagU(LInstruction* instr,
132                             LOperand* value,
133                             LOperand* temp1,
134                             LOperand* temp2);
135   void DoDeferredTaggedToI(LTaggedToI* instr,
136                            LOperand* value,
137                            LOperand* temp1,
138                            LOperand* temp2);
139   void DoDeferredAllocate(LAllocate* instr);
140   void DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr);
141   void DoDeferredInstanceMigration(LCheckMaps* instr, Register object);
142   void DoDeferredLoadMutableDouble(LLoadFieldByIndex* instr,
143                                    Register result,
144                                    Register object,
145                                    Register index);
146 
147   static Condition TokenToCondition(Token::Value op, bool is_unsigned);
148   void EmitGoto(int block);
149   void DoGap(LGap* instr);
150 
151   // Generic version of EmitBranch. It contains some code to avoid emitting a
152   // branch on the next emitted basic block where we could just fall-through.
153   // You shouldn't use that directly but rather consider one of the helper like
154   // LCodeGen::EmitBranch, LCodeGen::EmitCompareAndBranch...
155   template<class InstrType>
156   void EmitBranchGeneric(InstrType instr,
157                          const BranchGenerator& branch);
158 
159   template<class InstrType>
160   void EmitBranch(InstrType instr, Condition condition);
161 
162   template<class InstrType>
163   void EmitCompareAndBranch(InstrType instr,
164                             Condition condition,
165                             const Register& lhs,
166                             const Operand& rhs);
167 
168   template<class InstrType>
169   void EmitTestAndBranch(InstrType instr,
170                          Condition condition,
171                          const Register& value,
172                          uint64_t mask);
173 
174   template<class InstrType>
175   void EmitBranchIfNonZeroNumber(InstrType instr,
176                                  const FPRegister& value,
177                                  const FPRegister& scratch);
178 
179   template<class InstrType>
180   void EmitBranchIfHeapNumber(InstrType instr,
181                               const Register& value);
182 
183   template<class InstrType>
184   void EmitBranchIfRoot(InstrType instr,
185                         const Register& value,
186                         Heap::RootListIndex index);
187 
188   // Emits optimized code to deep-copy the contents of statically known object
189   // graphs (e.g. object literal boilerplate). Expects a pointer to the
190   // allocated destination object in the result register, and a pointer to the
191   // source object in the source register.
192   void EmitDeepCopy(Handle<JSObject> object,
193                     Register result,
194                     Register source,
195                     Register scratch,
196                     int* offset,
197                     AllocationSiteMode mode);
198 
199   template <class T>
200   void EmitVectorLoadICRegisters(T* instr);
201 
202   // Emits optimized code for %_IsString(x).  Preserves input register.
203   // Returns the condition on which a final split to
204   // true and false label should be made, to optimize fallthrough.
205   Condition EmitIsString(Register input, Register temp1, Label* is_not_string,
206                          SmiCheck check_needed);
207 
208   int DefineDeoptimizationLiteral(Handle<Object> literal);
209   void PopulateDeoptimizationData(Handle<Code> code);
210   void PopulateDeoptimizationLiteralsWithInlinedFunctions();
211 
212   MemOperand BuildSeqStringOperand(Register string,
213                                    Register temp,
214                                    LOperand* index,
215                                    String::Encoding encoding);
216   void DeoptimizeBranch(LInstruction* instr, const char* detail,
217                         BranchType branch_type, Register reg = NoReg,
218                         int bit = -1,
219                         Deoptimizer::BailoutType* override_bailout_type = NULL);
220   void Deoptimize(LInstruction* instr,
221                   Deoptimizer::BailoutType* override_bailout_type = NULL,
222                   const char* detail = NULL);
223   void DeoptimizeIf(Condition cond, LInstruction* instr,
224                     const char* detail = NULL);
225   void DeoptimizeIfZero(Register rt, LInstruction* instr,
226                         const char* detail = NULL);
227   void DeoptimizeIfNotZero(Register rt, LInstruction* instr,
228                            const char* detail = NULL);
229   void DeoptimizeIfNegative(Register rt, LInstruction* instr,
230                             const char* detail = NULL);
231   void DeoptimizeIfSmi(Register rt, LInstruction* instr,
232                        const char* detail = NULL);
233   void DeoptimizeIfNotSmi(Register rt, LInstruction* instr,
234                           const char* detail = NULL);
235   void DeoptimizeIfRoot(Register rt, Heap::RootListIndex index,
236                         LInstruction* instr, const char* detail = NULL);
237   void DeoptimizeIfNotRoot(Register rt, Heap::RootListIndex index,
238                            LInstruction* instr, const char* detail = NULL);
239   void DeoptimizeIfNotHeapNumber(Register object, LInstruction* instr);
240   void DeoptimizeIfMinusZero(DoubleRegister input, LInstruction* instr,
241                              const char* detail = NULL);
242   void DeoptimizeIfBitSet(Register rt, int bit, LInstruction* instr,
243                           const char* detail = NULL);
244   void DeoptimizeIfBitClear(Register rt, int bit, LInstruction* instr,
245                             const char* detail = NULL);
246 
247   MemOperand PrepareKeyedExternalArrayOperand(Register key,
248                                               Register base,
249                                               Register scratch,
250                                               bool key_is_smi,
251                                               bool key_is_constant,
252                                               int constant_key,
253                                               ElementsKind elements_kind,
254                                               int base_offset);
255   MemOperand PrepareKeyedArrayOperand(Register base,
256                                       Register elements,
257                                       Register key,
258                                       bool key_is_tagged,
259                                       ElementsKind elements_kind,
260                                       Representation representation,
261                                       int base_offset);
262 
263   void RegisterEnvironmentForDeoptimization(LEnvironment* environment,
264                                             Safepoint::DeoptMode mode);
265 
GetStackSlotCount()266   int GetStackSlotCount() const { return chunk()->spill_slot_count(); }
267 
AddDeferredCode(LDeferredCode * code)268   void AddDeferredCode(LDeferredCode* code) { deferred_.Add(code, zone()); }
269 
270   // Emit frame translation commands for an environment.
271   void WriteTranslation(LEnvironment* environment, Translation* translation);
272 
273   void AddToTranslation(LEnvironment* environment,
274                         Translation* translation,
275                         LOperand* op,
276                         bool is_tagged,
277                         bool is_uint32,
278                         int* object_index_pointer,
279                         int* dematerialized_index_pointer);
280 
281   void SaveCallerDoubles();
282   void RestoreCallerDoubles();
283 
284   // Code generation steps.  Returns true if code generation should continue.
285   void GenerateBodyInstructionPre(LInstruction* instr) OVERRIDE;
286   bool GeneratePrologue();
287   bool GenerateDeferredCode();
288   bool GenerateJumpTable();
289   bool GenerateSafepointTable();
290 
291   // Generates the custom OSR entrypoint and sets the osr_pc_offset.
292   void GenerateOsrPrologue();
293 
294   enum SafepointMode {
295     RECORD_SIMPLE_SAFEPOINT,
296     RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS
297   };
298 
299   void CallCode(Handle<Code> code,
300                 RelocInfo::Mode mode,
301                 LInstruction* instr);
302 
303   void CallCodeGeneric(Handle<Code> code,
304                        RelocInfo::Mode mode,
305                        LInstruction* instr,
306                        SafepointMode safepoint_mode);
307 
308   void CallRuntime(const Runtime::Function* function,
309                    int num_arguments,
310                    LInstruction* instr,
311                    SaveFPRegsMode save_doubles = kDontSaveFPRegs);
312 
CallRuntime(Runtime::FunctionId id,int num_arguments,LInstruction * instr)313   void CallRuntime(Runtime::FunctionId id,
314                    int num_arguments,
315                    LInstruction* instr) {
316     const Runtime::Function* function = Runtime::FunctionForId(id);
317     CallRuntime(function, num_arguments, instr);
318   }
319 
320   void LoadContextFromDeferred(LOperand* context);
321   void CallRuntimeFromDeferred(Runtime::FunctionId id,
322                                int argc,
323                                LInstruction* instr,
324                                LOperand* context);
325 
326   // Generate a direct call to a known function.
327   // If the function is already loaded into x1 by the caller, function_reg may
328   // be set to x1. Otherwise, it must be NoReg, and CallKnownFunction will
329   // automatically load it.
330   void CallKnownFunction(Handle<JSFunction> function,
331                          int formal_parameter_count,
332                          int arity,
333                          LInstruction* instr,
334                          Register function_reg = NoReg);
335 
336   // Support for recording safepoint and position information.
337   void RecordAndWritePosition(int position) OVERRIDE;
338   void RecordSafepoint(LPointerMap* pointers,
339                        Safepoint::Kind kind,
340                        int arguments,
341                        Safepoint::DeoptMode mode);
342   void RecordSafepoint(LPointerMap* pointers, Safepoint::DeoptMode mode);
343   void RecordSafepoint(Safepoint::DeoptMode mode);
344   void RecordSafepointWithRegisters(LPointerMap* pointers,
345                                     int arguments,
346                                     Safepoint::DeoptMode mode);
347   void RecordSafepointWithLazyDeopt(LInstruction* instr,
348                                     SafepointMode safepoint_mode);
349 
350   void EnsureSpaceForLazyDeopt(int space_needed) OVERRIDE;
351 
352   ZoneList<LEnvironment*> deoptimizations_;
353   ZoneList<Deoptimizer::JumpTableEntry*> jump_table_;
354   ZoneList<Handle<Object> > deoptimization_literals_;
355   int inlined_function_count_;
356   Scope* const scope_;
357   TranslationBuffer translations_;
358   ZoneList<LDeferredCode*> deferred_;
359   int osr_pc_offset_;
360   bool frame_is_built_;
361 
362   // Builder that keeps track of safepoints in the code. The table itself is
363   // emitted at the end of the generated code.
364   SafepointTableBuilder safepoints_;
365 
366   // Compiler from a set of parallel moves to a sequential list of moves.
367   LGapResolver resolver_;
368 
369   Safepoint::Kind expected_safepoint_kind_;
370 
371   // This flag is true when we are after a push (but before a call).
372   // In this situation, jssp no longer references the end of the stack slots so,
373   // we can only reference a stack slot via fp.
374   bool after_push_argument_;
375   // If we have inlined arguments, we are no longer able to use jssp because
376   // jssp is modified and we never know if we are in a block after or before
377   // the pop of the arguments (which restores jssp).
378   bool inlined_arguments_;
379 
380   int old_position_;
381 
382   class PushSafepointRegistersScope BASE_EMBEDDED {
383    public:
PushSafepointRegistersScope(LCodeGen * codegen)384     explicit PushSafepointRegistersScope(LCodeGen* codegen)
385         : codegen_(codegen) {
386       DCHECK(codegen_->info()->is_calling());
387       DCHECK(codegen_->expected_safepoint_kind_ == Safepoint::kSimple);
388       codegen_->expected_safepoint_kind_ = Safepoint::kWithRegisters;
389 
390       UseScratchRegisterScope temps(codegen_->masm_);
391       // Preserve the value of lr which must be saved on the stack (the call to
392       // the stub will clobber it).
393       Register to_be_pushed_lr =
394           temps.UnsafeAcquire(StoreRegistersStateStub::to_be_pushed_lr());
395       codegen_->masm_->Mov(to_be_pushed_lr, lr);
396       StoreRegistersStateStub stub(codegen_->isolate());
397       codegen_->masm_->CallStub(&stub);
398     }
399 
~PushSafepointRegistersScope()400     ~PushSafepointRegistersScope() {
401       DCHECK(codegen_->expected_safepoint_kind_ == Safepoint::kWithRegisters);
402       RestoreRegistersStateStub stub(codegen_->isolate());
403       codegen_->masm_->CallStub(&stub);
404       codegen_->expected_safepoint_kind_ = Safepoint::kSimple;
405     }
406 
407    private:
408     LCodeGen* codegen_;
409   };
410 
411   friend class LDeferredCode;
412   friend class SafepointGenerator;
413   DISALLOW_COPY_AND_ASSIGN(LCodeGen);
414 };
415 
416 
417 class LDeferredCode: public ZoneObject {
418  public:
LDeferredCode(LCodeGen * codegen)419   explicit LDeferredCode(LCodeGen* codegen)
420       : codegen_(codegen),
421         external_exit_(NULL),
422         instruction_index_(codegen->current_instruction_) {
423     codegen->AddDeferredCode(this);
424   }
425 
~LDeferredCode()426   virtual ~LDeferredCode() { }
427   virtual void Generate() = 0;
428   virtual LInstruction* instr() = 0;
429 
SetExit(Label * exit)430   void SetExit(Label* exit) { external_exit_ = exit; }
entry()431   Label* entry() { return &entry_; }
exit()432   Label* exit() { return (external_exit_ != NULL) ? external_exit_ : &exit_; }
instruction_index()433   int instruction_index() const { return instruction_index_; }
434 
435  protected:
codegen()436   LCodeGen* codegen() const { return codegen_; }
masm()437   MacroAssembler* masm() const { return codegen_->masm(); }
438 
439  private:
440   LCodeGen* codegen_;
441   Label entry_;
442   Label exit_;
443   Label* external_exit_;
444   int instruction_index_;
445 };
446 
447 
448 // This is the abstract class used by EmitBranchGeneric.
449 // It is used to emit code for conditional branching. The Emit() function
450 // emits code to branch when the condition holds and EmitInverted() emits
451 // the branch when the inverted condition is verified.
452 //
453 // For actual examples of condition see the concrete implementation in
454 // lithium-codegen-arm64.cc (e.g. BranchOnCondition, CompareAndBranch).
455 class BranchGenerator BASE_EMBEDDED {
456  public:
BranchGenerator(LCodeGen * codegen)457   explicit BranchGenerator(LCodeGen* codegen)
458     : codegen_(codegen) { }
459 
~BranchGenerator()460   virtual ~BranchGenerator() { }
461 
462   virtual void Emit(Label* label) const = 0;
463   virtual void EmitInverted(Label* label) const = 0;
464 
465  protected:
masm()466   MacroAssembler* masm() const { return codegen_->masm(); }
467 
468   LCodeGen* codegen_;
469 };
470 
471 } }  // namespace v8::internal
472 
473 #endif  // V8_ARM64_LITHIUM_CODEGEN_ARM64_H_
474