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         deopt_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   // Emits optimized code for %_IsString(x).  Preserves input register.
 200   // Returns the condition on which a final split to
 201   // true and false label should be made, to optimize fallthrough.
 202   Condition EmitIsString(Register input, Register temp1, Label* is_not_string,
 203                          SmiCheck check_needed);
 204
 205   int DefineDeoptimizationLiteral(Handle<Object> literal);
 206   void PopulateDeoptimizationData(Handle<Code> code);
 207   void PopulateDeoptimizationLiteralsWithInlinedFunctions();
 208
 209   MemOperand BuildSeqStringOperand(Register string,
 210                                    Register temp,
 211                                    LOperand* index,
 212                                    String::Encoding encoding);
 213   void DeoptimizeBranch(
 214       LEnvironment* environment,
 215       BranchType branch_type, Register reg = NoReg, int bit = -1,
 216       Deoptimizer::BailoutType* override_bailout_type = NULL);
 217   void Deoptimize(LEnvironment* environment,
 218                   Deoptimizer::BailoutType* override_bailout_type = NULL);
 219   void DeoptimizeIf(Condition cond, LEnvironment* environment);
 220   void DeoptimizeIfZero(Register rt, LEnvironment* environment);
 221   void DeoptimizeIfNotZero(Register rt, LEnvironment* environment);
 222   void DeoptimizeIfNegative(Register rt, LEnvironment* environment);
 223   void DeoptimizeIfSmi(Register rt, LEnvironment* environment);
 224   void DeoptimizeIfNotSmi(Register rt, LEnvironment* environment);
 225   void DeoptimizeIfRoot(Register rt,
 226                         Heap::RootListIndex index,
 227                         LEnvironment* environment);
 228   void DeoptimizeIfNotRoot(Register rt,
 229                            Heap::RootListIndex index,
 230                            LEnvironment* environment);
 231   void DeoptimizeIfMinusZero(DoubleRegister input, LEnvironment* environment);
 232   void DeoptimizeIfBitSet(Register rt, int bit, LEnvironment* environment);
 233   void DeoptimizeIfBitClear(Register rt, int bit, LEnvironment* environment);
 234
 235   MemOperand PrepareKeyedExternalArrayOperand(Register key,
 236                                               Register base,
 237                                               Register scratch,
 238                                               bool key_is_smi,
 239                                               bool key_is_constant,
 240                                               int constant_key,
 241                                               ElementsKind elements_kind,
 242                                               int base_offset);
 243   MemOperand PrepareKeyedArrayOperand(Register base,
 244                                       Register elements,
 245                                       Register key,
 246                                       bool key_is_tagged,
 247                                       ElementsKind elements_kind,
 248                                       Representation representation,
 249                                       int base_offset);
 250
 251   void RegisterEnvironmentForDeoptimization(LEnvironment* environment,
 252                                             Safepoint::DeoptMode mode);
 253
 254   int GetStackSlotCount() const { return chunk()->spill_slot_count(); }
 255
 256   void AddDeferredCode(LDeferredCode* code) { deferred_.Add(code, zone()); }
 257
 258   // Emit frame translation commands for an environment.
 259   void WriteTranslation(LEnvironment* environment, Translation* translation);
 260
 261   void AddToTranslation(LEnvironment* environment,
 262                         Translation* translation,
 263                         LOperand* op,
 264                         bool is_tagged,
 265                         bool is_uint32,
 266                         int* object_index_pointer,
 267                         int* dematerialized_index_pointer);
 268
 269   void SaveCallerDoubles();
 270   void RestoreCallerDoubles();
 271
 272   // Code generation steps.  Returns true if code generation should continue.
 273   void GenerateBodyInstructionPre(LInstruction* instr) V8_OVERRIDE;
 274   bool GeneratePrologue();
 275   bool GenerateDeferredCode();
 276   bool GenerateDeoptJumpTable();
 277   bool GenerateSafepointTable();
 278
 279   // Generates the custom OSR entrypoint and sets the osr_pc_offset.
 280   void GenerateOsrPrologue();
 281
 282   enum SafepointMode {
 283     RECORD_SIMPLE_SAFEPOINT,
 284     RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS
 285   };
 286
 287   void CallCode(Handle<Code> code,
 288                 RelocInfo::Mode mode,
 289                 LInstruction* instr);
 290
 291   void CallCodeGeneric(Handle<Code> code,
 292                        RelocInfo::Mode mode,
 293                        LInstruction* instr,
 294                        SafepointMode safepoint_mode);
 295
 296   void CallRuntime(const Runtime::Function* function,
 297                    int num_arguments,
 298                    LInstruction* instr,
 299                    SaveFPRegsMode save_doubles = kDontSaveFPRegs);
 300
 301   void CallRuntime(Runtime::FunctionId id,
 302                    int num_arguments,
 303                    LInstruction* instr) {
 304     const Runtime::Function* function = Runtime::FunctionForId(id);
 305     CallRuntime(function, num_arguments, instr);
 306   }
 307
 308   void LoadContextFromDeferred(LOperand* context);
 309   void CallRuntimeFromDeferred(Runtime::FunctionId id,
 310                                int argc,
 311                                LInstruction* instr,
 312                                LOperand* context);
 313
 314   // Generate a direct call to a known function.
 315   // If the function is already loaded into x1 by the caller, function_reg may
 316   // be set to x1. Otherwise, it must be NoReg, and CallKnownFunction will
 317   // automatically load it.
 318   void CallKnownFunction(Handle<JSFunction> function,
 319                          int formal_parameter_count,
 320                          int arity,
 321                          LInstruction* instr,
 322                          Register function_reg = NoReg);
 323
 324   // Support for recording safepoint and position information.
 325   void RecordAndWritePosition(int position) V8_OVERRIDE;
 326   void RecordSafepoint(LPointerMap* pointers,
 327                        Safepoint::Kind kind,
 328                        int arguments,
 329                        Safepoint::DeoptMode mode);
 330   void RecordSafepoint(LPointerMap* pointers, Safepoint::DeoptMode mode);
 331   void RecordSafepoint(Safepoint::DeoptMode mode);
 332   void RecordSafepointWithRegisters(LPointerMap* pointers,
 333                                     int arguments,
 334                                     Safepoint::DeoptMode mode);
 335   void RecordSafepointWithLazyDeopt(LInstruction* instr,
 336                                     SafepointMode safepoint_mode);
 337
 338   void EnsureSpaceForLazyDeopt(int space_needed) V8_OVERRIDE;
 339
 340   ZoneList<LEnvironment*> deoptimizations_;
 341   ZoneList<Deoptimizer::JumpTableEntry*> deopt_jump_table_;
 342   ZoneList<Handle<Object> > deoptimization_literals_;
 343   int inlined_function_count_;
 344   Scope* const scope_;
 345   TranslationBuffer translations_;
 346   ZoneList<LDeferredCode*> deferred_;
 347   int osr_pc_offset_;
 348   bool frame_is_built_;
 349
 350   // Builder that keeps track of safepoints in the code. The table itself is
 351   // emitted at the end of the generated code.
 352   SafepointTableBuilder safepoints_;
 353
 354   // Compiler from a set of parallel moves to a sequential list of moves.
 355   LGapResolver resolver_;
 356
 357   Safepoint::Kind expected_safepoint_kind_;
 358
 359   // This flag is true when we are after a push (but before a call).
 360   // In this situation, jssp no longer references the end of the stack slots so,
 361   // we can only reference a stack slot via fp.
 362   bool after_push_argument_;
 363   // If we have inlined arguments, we are no longer able to use jssp because
 364   // jssp is modified and we never know if we are in a block after or before
 365   // the pop of the arguments (which restores jssp).
 366   bool inlined_arguments_;
 367
 368   int old_position_;
 369
 370   class PushSafepointRegistersScope BASE_EMBEDDED {
 371    public:
 372     explicit PushSafepointRegistersScope(LCodeGen* codegen)
 373         : codegen_(codegen) {
 374       DCHECK(codegen_->info()->is_calling());
 375       DCHECK(codegen_->expected_safepoint_kind_ == Safepoint::kSimple);
 376       codegen_->expected_safepoint_kind_ = Safepoint::kWithRegisters;
 377
 378       UseScratchRegisterScope temps(codegen_->masm_);
 379       // Preserve the value of lr which must be saved on the stack (the call to
 380       // the stub will clobber it).
 381       Register to_be_pushed_lr =
 382           temps.UnsafeAcquire(StoreRegistersStateStub::to_be_pushed_lr());
 383       codegen_->masm_->Mov(to_be_pushed_lr, lr);
 384       StoreRegistersStateStub stub(codegen_->isolate());
 385       codegen_->masm_->CallStub(&stub);
 386     }
 387
 388     ~PushSafepointRegistersScope() {
 389       DCHECK(codegen_->expected_safepoint_kind_ == Safepoint::kWithRegisters);
 390       RestoreRegistersStateStub stub(codegen_->isolate());
 391       codegen_->masm_->CallStub(&stub);
 392       codegen_->expected_safepoint_kind_ = Safepoint::kSimple;
 393     }
 394
 395    private:
 396     LCodeGen* codegen_;
 397   };
 398
 399   friend class LDeferredCode;
 400   friend class SafepointGenerator;
 401   DISALLOW_COPY_AND_ASSIGN(LCodeGen);
 402 };
 403
 404
 405 class LDeferredCode: public ZoneObject {
 406  public:
 407   explicit LDeferredCode(LCodeGen* codegen)
 408       : codegen_(codegen),
 409         external_exit_(NULL),
 410         instruction_index_(codegen->current_instruction_) {
 411     codegen->AddDeferredCode(this);
 412   }
 413
 414   virtual ~LDeferredCode() { }
 415   virtual void Generate() = 0;
 416   virtual LInstruction* instr() = 0;
 417
 418   void SetExit(Label* exit) { external_exit_ = exit; }
 419   Label* entry() { return &entry_; }
 420   Label* exit() { return (external_exit_ != NULL) ? external_exit_ : &exit_; }
 421   int instruction_index() const { return instruction_index_; }
 422
 423  protected:
 424   LCodeGen* codegen() const { return codegen_; }
 425   MacroAssembler* masm() const { return codegen_->masm(); }
 426
 427  private:
 428   LCodeGen* codegen_;
 429   Label entry_;
 430   Label exit_;
 431   Label* external_exit_;
 432   int instruction_index_;
 433 };
 434
 435
 436 // This is the abstract class used by EmitBranchGeneric.
 437 // It is used to emit code for conditional branching. The Emit() function
 438 // emits code to branch when the condition holds and EmitInverted() emits
 439 // the branch when the inverted condition is verified.
 440 //
 441 // For actual examples of condition see the concrete implementation in
 442 // lithium-codegen-arm64.cc (e.g. BranchOnCondition, CompareAndBranch).
 443 class BranchGenerator BASE_EMBEDDED {
 444  public:
 445   explicit BranchGenerator(LCodeGen* codegen)
 446     : codegen_(codegen) { }
 447
 448   virtual ~BranchGenerator() { }
 449
 450   virtual void Emit(Label* label) const = 0;
 451   virtual void EmitInverted(Label* label) const = 0;
 452
 453  protected:
 454   MacroAssembler* masm() const { return codegen_->masm(); }
 455
 456   LCodeGen* codegen_;
 457 };
 458
 459 } }  // namespace v8::internal
 460
 461 #endif  // V8_ARM64_LITHIUM_CODEGEN_ARM64_H_