src/arm64/lithium-codegen-arm64.h

   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:
  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
  46   ~LCodeGen() {
  47     DCHECK(!after_push_argument_ || inlined_arguments_);
  48   }
  49
  50   // Simple accessors.
  51   Scope* scope() const { return scope_; }
  52
  53   int LookupDestination(int block_id) const {
  54     return chunk()->LookupDestination(block_id);
  55   }
  56
  57   bool IsNextEmittedBlock(int block_id) const {
  58     return LookupDestination(block_id) == GetNextEmittedBlock();
  59   }
  60
  61   bool NeedsEagerFrame() const {
  62     return GetStackSlotCount() > 0 ||
  63         info()->is_non_deferred_calling() ||
  64         !info()->IsStub() ||
  65         info()->requires_frame();
  66   }
  67   bool NeedsDeferredFrame() const {
  68     return !NeedsEagerFrame() && info()->is_deferred_calling();
  69   }
  70
  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
  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);
 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,
 217                         Deoptimizer::DeoptReason deopt_reason,
 218                         BranchType branch_type, Register reg = NoReg,
 219                         int bit = -1,
 220                         Deoptimizer::BailoutType* override_bailout_type = NULL);
 221   void Deoptimize(LInstruction* instr, Deoptimizer::DeoptReason deopt_reason,
 222                   Deoptimizer::BailoutType* override_bailout_type = NULL);
 223   void DeoptimizeIf(Condition cond, LInstruction* instr,
 224                     Deoptimizer::DeoptReason deopt_reason);
 225   void DeoptimizeIfZero(Register rt, LInstruction* instr,
 226                         Deoptimizer::DeoptReason deopt_reason);
 227   void DeoptimizeIfNotZero(Register rt, LInstruction* instr,
 228                            Deoptimizer::DeoptReason deopt_reason);
 229   void DeoptimizeIfNegative(Register rt, LInstruction* instr,
 230                             Deoptimizer::DeoptReason deopt_reason);
 231   void DeoptimizeIfSmi(Register rt, LInstruction* instr,
 232                        Deoptimizer::DeoptReason deopt_reason);
 233   void DeoptimizeIfNotSmi(Register rt, LInstruction* instr,
 234                           Deoptimizer::DeoptReason deopt_reason);
 235   void DeoptimizeIfRoot(Register rt, Heap::RootListIndex index,
 236                         LInstruction* instr,
 237                         Deoptimizer::DeoptReason deopt_reason);
 238   void DeoptimizeIfNotRoot(Register rt, Heap::RootListIndex index,
 239                            LInstruction* instr,
 240                            Deoptimizer::DeoptReason deopt_reason);
 241   void DeoptimizeIfNotHeapNumber(Register object, LInstruction* instr);
 242   void DeoptimizeIfMinusZero(DoubleRegister input, LInstruction* instr,
 243                              Deoptimizer::DeoptReason deopt_reason);
 244   void DeoptimizeIfBitSet(Register rt, int bit, LInstruction* instr,
 245                           Deoptimizer::DeoptReason deopt_reason);
 246   void DeoptimizeIfBitClear(Register rt, int bit, LInstruction* instr,
 247                             Deoptimizer::DeoptReason deopt_reason);
 248
 249   MemOperand PrepareKeyedExternalArrayOperand(Register key,
 250                                               Register base,
 251                                               Register scratch,
 252                                               bool key_is_smi,
 253                                               bool key_is_constant,
 254                                               int constant_key,
 255                                               ElementsKind elements_kind,
 256                                               int base_offset);
 257   MemOperand PrepareKeyedArrayOperand(Register base,
 258                                       Register elements,
 259                                       Register key,
 260                                       bool key_is_tagged,
 261                                       ElementsKind elements_kind,
 262                                       Representation representation,
 263                                       int base_offset);
 264
 265   void RegisterEnvironmentForDeoptimization(LEnvironment* environment,
 266                                             Safepoint::DeoptMode mode);
 267
 268   int GetStackSlotCount() const { return chunk()->spill_slot_count(); }
 269
 270   void AddDeferredCode(LDeferredCode* code) { deferred_.Add(code, zone()); }
 271
 272   // Emit frame translation commands for an environment.
 273   void WriteTranslation(LEnvironment* environment, Translation* translation);
 274
 275   void AddToTranslation(LEnvironment* environment,
 276                         Translation* translation,
 277                         LOperand* op,
 278                         bool is_tagged,
 279                         bool is_uint32,
 280                         int* object_index_pointer,
 281                         int* dematerialized_index_pointer);
 282
 283   void SaveCallerDoubles();
 284   void RestoreCallerDoubles();
 285
 286   // Code generation steps.  Returns true if code generation should continue.
 287   void GenerateBodyInstructionPre(LInstruction* instr) OVERRIDE;
 288   bool GeneratePrologue();
 289   bool GenerateDeferredCode();
 290   bool GenerateJumpTable();
 291   bool GenerateSafepointTable();
 292
 293   // Generates the custom OSR entrypoint and sets the osr_pc_offset.
 294   void GenerateOsrPrologue();
 295
 296   enum SafepointMode {
 297     RECORD_SIMPLE_SAFEPOINT,
 298     RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS
 299   };
 300
 301   void CallCode(Handle<Code> code,
 302                 RelocInfo::Mode mode,
 303                 LInstruction* instr);
 304
 305   void CallCodeGeneric(Handle<Code> code,
 306                        RelocInfo::Mode mode,
 307                        LInstruction* instr,
 308                        SafepointMode safepoint_mode);
 309
 310   void CallRuntime(const Runtime::Function* function,
 311                    int num_arguments,
 312                    LInstruction* instr,
 313                    SaveFPRegsMode save_doubles = kDontSaveFPRegs);
 314
 315   void CallRuntime(Runtime::FunctionId id,
 316                    int num_arguments,
 317                    LInstruction* instr) {
 318     const Runtime::Function* function = Runtime::FunctionForId(id);
 319     CallRuntime(function, num_arguments, instr);
 320   }
 321
 322   void LoadContextFromDeferred(LOperand* context);
 323   void CallRuntimeFromDeferred(Runtime::FunctionId id,
 324                                int argc,
 325                                LInstruction* instr,
 326                                LOperand* context);
 327
 328   // Generate a direct call to a known function.  Expects the function
 329   // to be in x1.
 330   void CallKnownFunction(Handle<JSFunction> function,
 331                          int formal_parameter_count, int arity,
 332                          LInstruction* instr);
 333
 334   // Support for recording safepoint and position information.
 335   void RecordAndWritePosition(int position) OVERRIDE;
 336   void RecordSafepoint(LPointerMap* pointers,
 337                        Safepoint::Kind kind,
 338                        int arguments,
 339                        Safepoint::DeoptMode mode);
 340   void RecordSafepoint(LPointerMap* pointers, Safepoint::DeoptMode mode);
 341   void RecordSafepoint(Safepoint::DeoptMode mode);
 342   void RecordSafepointWithRegisters(LPointerMap* pointers,
 343                                     int arguments,
 344                                     Safepoint::DeoptMode mode);
 345   void RecordSafepointWithLazyDeopt(LInstruction* instr,
 346                                     SafepointMode safepoint_mode);
 347
 348   void EnsureSpaceForLazyDeopt(int space_needed) OVERRIDE;
 349
 350   ZoneList<LEnvironment*> deoptimizations_;
 351   ZoneList<Deoptimizer::JumpTableEntry*> jump_table_;
 352   ZoneList<Handle<Object> > deoptimization_literals_;
 353   int inlined_function_count_;
 354   Scope* const scope_;
 355   TranslationBuffer translations_;
 356   ZoneList<LDeferredCode*> deferred_;
 357   int osr_pc_offset_;
 358   bool frame_is_built_;
 359
 360   // Builder that keeps track of safepoints in the code. The table itself is
 361   // emitted at the end of the generated code.
 362   SafepointTableBuilder safepoints_;
 363
 364   // Compiler from a set of parallel moves to a sequential list of moves.
 365   LGapResolver resolver_;
 366
 367   Safepoint::Kind expected_safepoint_kind_;
 368
 369   // This flag is true when we are after a push (but before a call).
 370   // In this situation, jssp no longer references the end of the stack slots so,
 371   // we can only reference a stack slot via fp.
 372   bool after_push_argument_;
 373   // If we have inlined arguments, we are no longer able to use jssp because
 374   // jssp is modified and we never know if we are in a block after or before
 375   // the pop of the arguments (which restores jssp).
 376   bool inlined_arguments_;
 377
 378   int old_position_;
 379
 380   class PushSafepointRegistersScope BASE_EMBEDDED {
 381    public:
 382     explicit PushSafepointRegistersScope(LCodeGen* codegen)
 383         : codegen_(codegen) {
 384       DCHECK(codegen_->info()->is_calling());
 385       DCHECK(codegen_->expected_safepoint_kind_ == Safepoint::kSimple);
 386       codegen_->expected_safepoint_kind_ = Safepoint::kWithRegisters;
 387
 388       UseScratchRegisterScope temps(codegen_->masm_);
 389       // Preserve the value of lr which must be saved on the stack (the call to
 390       // the stub will clobber it).
 391       Register to_be_pushed_lr =
 392           temps.UnsafeAcquire(StoreRegistersStateStub::to_be_pushed_lr());
 393       codegen_->masm_->Mov(to_be_pushed_lr, lr);
 394       StoreRegistersStateStub stub(codegen_->isolate());
 395       codegen_->masm_->CallStub(&stub);
 396     }
 397
 398     ~PushSafepointRegistersScope() {
 399       DCHECK(codegen_->expected_safepoint_kind_ == Safepoint::kWithRegisters);
 400       RestoreRegistersStateStub stub(codegen_->isolate());
 401       codegen_->masm_->CallStub(&stub);
 402       codegen_->expected_safepoint_kind_ = Safepoint::kSimple;
 403     }
 404
 405    private:
 406     LCodeGen* codegen_;
 407   };
 408
 409   friend class LDeferredCode;
 410   friend class SafepointGenerator;
 411   DISALLOW_COPY_AND_ASSIGN(LCodeGen);
 412 };
 413
 414
 415 class LDeferredCode: public ZoneObject {
 416  public:
 417   explicit LDeferredCode(LCodeGen* codegen)
 418       : codegen_(codegen),
 419         external_exit_(NULL),
 420         instruction_index_(codegen->current_instruction_) {
 421     codegen->AddDeferredCode(this);
 422   }
 423
 424   virtual ~LDeferredCode() { }
 425   virtual void Generate() = 0;
 426   virtual LInstruction* instr() = 0;
 427
 428   void SetExit(Label* exit) { external_exit_ = exit; }
 429   Label* entry() { return &entry_; }
 430   Label* exit() { return (external_exit_ != NULL) ? external_exit_ : &exit_; }
 431   int instruction_index() const { return instruction_index_; }
 432
 433  protected:
 434   LCodeGen* codegen() const { return codegen_; }
 435   MacroAssembler* masm() const { return codegen_->masm(); }
 436
 437  private:
 438   LCodeGen* codegen_;
 439   Label entry_;
 440   Label exit_;
 441   Label* external_exit_;
 442   int instruction_index_;
 443 };
 444
 445
 446 // This is the abstract class used by EmitBranchGeneric.
 447 // It is used to emit code for conditional branching. The Emit() function
 448 // emits code to branch when the condition holds and EmitInverted() emits
 449 // the branch when the inverted condition is verified.
 450 //
 451 // For actual examples of condition see the concrete implementation in
 452 // lithium-codegen-arm64.cc (e.g. BranchOnCondition, CompareAndBranch).
 453 class BranchGenerator BASE_EMBEDDED {
 454  public:
 455   explicit BranchGenerator(LCodeGen* codegen)
 456     : codegen_(codegen) { }
 457
 458   virtual ~BranchGenerator() { }
 459
 460   virtual void Emit(Label* label) const = 0;
 461   virtual void EmitInverted(Label* label) const = 0;
 462
 463  protected:
 464   MacroAssembler* masm() const { return codegen_->masm(); }
 465
 466   LCodeGen* codegen_;
 467 };
 468
 469 } }  // namespace v8::internal
 470
 471 #endif  // V8_ARM64_LITHIUM_CODEGEN_ARM64_H_