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     ASSERT(!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   // LOperand must be a register.
  87   Register ToRegister(LOperand* op) const;
  88   Register ToRegister32(LOperand* op) const;
  89   Operand ToOperand(LOperand* op);
  90   Operand ToOperand32I(LOperand* op);
  91   Operand ToOperand32U(LOperand* op);
  92   enum StackMode { kMustUseFramePointer, kCanUseStackPointer };
  93   MemOperand ToMemOperand(LOperand* op,
  94                           StackMode stack_mode = kCanUseStackPointer) const;
  95   Handle<Object> ToHandle(LConstantOperand* op) const;
  96
  97   template<class LI>
  98   Operand ToShiftedRightOperand32I(LOperand* right,
  99                                    LI* shift_info) {
 100     return ToShiftedRightOperand32(right, shift_info, SIGNED_INT32);
 101   }
 102   template<class LI>
 103   Operand ToShiftedRightOperand32U(LOperand* right,
 104                                    LI* shift_info) {
 105     return ToShiftedRightOperand32(right, shift_info, UNSIGNED_INT32);
 106   }
 107   template<class LI>
 108   Operand ToShiftedRightOperand32(LOperand* right,
 109                                   LI* shift_info,
 110                                   IntegerSignedness signedness);
 111
 112   int JSShiftAmountFromLConstant(LOperand* constant) {
 113     return ToInteger32(LConstantOperand::cast(constant)) & 0x1f;
 114   }
 115
 116   // TODO(jbramley): Examine these helpers and check that they make sense.
 117   // IsInteger32Constant returns true for smi constants, for example.
 118   bool IsInteger32Constant(LConstantOperand* op) const;
 119   bool IsSmi(LConstantOperand* op) const;
 120
 121   int32_t ToInteger32(LConstantOperand* op) const;
 122   Smi* ToSmi(LConstantOperand* op) const;
 123   double ToDouble(LConstantOperand* op) const;
 124   DoubleRegister ToDoubleRegister(LOperand* op) const;
 125
 126   // Declare methods that deal with the individual node types.
 127 #define DECLARE_DO(type) void Do##type(L##type* node);
 128   LITHIUM_CONCRETE_INSTRUCTION_LIST(DECLARE_DO)
 129 #undef DECLARE_DO
 130
 131  private:
 132   // Return a double scratch register which can be used locally
 133   // when generating code for a lithium instruction.
 134   DoubleRegister double_scratch() { return crankshaft_fp_scratch; }
 135
 136   // Deferred code support.
 137   void DoDeferredNumberTagD(LNumberTagD* instr);
 138   void DoDeferredStackCheck(LStackCheck* instr);
 139   void DoDeferredStringCharCodeAt(LStringCharCodeAt* instr);
 140   void DoDeferredStringCharFromCode(LStringCharFromCode* instr);
 141   void DoDeferredMathAbsTagged(LMathAbsTagged* instr,
 142                                Label* exit,
 143                                Label* allocation_entry);
 144
 145   void DoDeferredNumberTagU(LInstruction* instr,
 146                             LOperand* value,
 147                             LOperand* temp1,
 148                             LOperand* temp2);
 149   void DoDeferredTaggedToI(LTaggedToI* instr,
 150                            LOperand* value,
 151                            LOperand* temp1,
 152                            LOperand* temp2);
 153   void DoDeferredAllocate(LAllocate* instr);
 154   void DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr);
 155   void DoDeferredInstanceMigration(LCheckMaps* instr, Register object);
 156   void DoDeferredLoadMutableDouble(LLoadFieldByIndex* instr,
 157                                    Register result,
 158                                    Register object,
 159                                    Register index);
 160
 161   Operand ToOperand32(LOperand* op, IntegerSignedness signedness);
 162
 163   static Condition TokenToCondition(Token::Value op, bool is_unsigned);
 164   void EmitGoto(int block);
 165   void DoGap(LGap* instr);
 166
 167   // Generic version of EmitBranch. It contains some code to avoid emitting a
 168   // branch on the next emitted basic block where we could just fall-through.
 169   // You shouldn't use that directly but rather consider one of the helper like
 170   // LCodeGen::EmitBranch, LCodeGen::EmitCompareAndBranch...
 171   template<class InstrType>
 172   void EmitBranchGeneric(InstrType instr,
 173                          const BranchGenerator& branch);
 174
 175   template<class InstrType>
 176   void EmitBranch(InstrType instr, Condition condition);
 177
 178   template<class InstrType>
 179   void EmitCompareAndBranch(InstrType instr,
 180                             Condition condition,
 181                             const Register& lhs,
 182                             const Operand& rhs);
 183
 184   template<class InstrType>
 185   void EmitTestAndBranch(InstrType instr,
 186                          Condition condition,
 187                          const Register& value,
 188                          uint64_t mask);
 189
 190   template<class InstrType>
 191   void EmitBranchIfNonZeroNumber(InstrType instr,
 192                                  const FPRegister& value,
 193                                  const FPRegister& scratch);
 194
 195   template<class InstrType>
 196   void EmitBranchIfHeapNumber(InstrType instr,
 197                               const Register& value);
 198
 199   template<class InstrType>
 200   void EmitBranchIfRoot(InstrType instr,
 201                         const Register& value,
 202                         Heap::RootListIndex index);
 203
 204   // Emits optimized code to deep-copy the contents of statically known object
 205   // graphs (e.g. object literal boilerplate). Expects a pointer to the
 206   // allocated destination object in the result register, and a pointer to the
 207   // source object in the source register.
 208   void EmitDeepCopy(Handle<JSObject> object,
 209                     Register result,
 210                     Register source,
 211                     Register scratch,
 212                     int* offset,
 213                     AllocationSiteMode mode);
 214
 215   // Emits optimized code for %_IsString(x).  Preserves input register.
 216   // Returns the condition on which a final split to
 217   // true and false label should be made, to optimize fallthrough.
 218   Condition EmitIsString(Register input, Register temp1, Label* is_not_string,
 219                          SmiCheck check_needed);
 220
 221   int DefineDeoptimizationLiteral(Handle<Object> literal);
 222   void PopulateDeoptimizationData(Handle<Code> code);
 223   void PopulateDeoptimizationLiteralsWithInlinedFunctions();
 224
 225   MemOperand BuildSeqStringOperand(Register string,
 226                                    Register temp,
 227                                    LOperand* index,
 228                                    String::Encoding encoding);
 229   void DeoptimizeBranch(
 230       LEnvironment* environment,
 231       BranchType branch_type, Register reg = NoReg, int bit = -1,
 232       Deoptimizer::BailoutType* override_bailout_type = NULL);
 233   void Deoptimize(LEnvironment* environment,
 234                   Deoptimizer::BailoutType* override_bailout_type = NULL);
 235   void DeoptimizeIf(Condition cond, LEnvironment* environment);
 236   void DeoptimizeIfZero(Register rt, LEnvironment* environment);
 237   void DeoptimizeIfNotZero(Register rt, LEnvironment* environment);
 238   void DeoptimizeIfNegative(Register rt, LEnvironment* environment);
 239   void DeoptimizeIfSmi(Register rt, LEnvironment* environment);
 240   void DeoptimizeIfNotSmi(Register rt, LEnvironment* environment);
 241   void DeoptimizeIfRoot(Register rt,
 242                         Heap::RootListIndex index,
 243                         LEnvironment* environment);
 244   void DeoptimizeIfNotRoot(Register rt,
 245                            Heap::RootListIndex index,
 246                            LEnvironment* environment);
 247   void DeoptimizeIfMinusZero(DoubleRegister input, LEnvironment* environment);
 248   void DeoptimizeIfBitSet(Register rt, int bit, LEnvironment* environment);
 249   void DeoptimizeIfBitClear(Register rt, int bit, LEnvironment* environment);
 250
 251   MemOperand PrepareKeyedExternalArrayOperand(Register key,
 252                                               Register base,
 253                                               Register scratch,
 254                                               bool key_is_smi,
 255                                               bool key_is_constant,
 256                                               int constant_key,
 257                                               ElementsKind elements_kind,
 258                                               int base_offset);
 259   MemOperand PrepareKeyedArrayOperand(Register base,
 260                                       Register elements,
 261                                       Register key,
 262                                       bool key_is_tagged,
 263                                       ElementsKind elements_kind,
 264                                       Representation representation,
 265                                       int base_offset);
 266
 267   void RegisterEnvironmentForDeoptimization(LEnvironment* environment,
 268                                             Safepoint::DeoptMode mode);
 269
 270   int GetStackSlotCount() const { return chunk()->spill_slot_count(); }
 271
 272   void AddDeferredCode(LDeferredCode* code) { deferred_.Add(code, zone()); }
 273
 274   // Emit frame translation commands for an environment.
 275   void WriteTranslation(LEnvironment* environment, Translation* translation);
 276
 277   void AddToTranslation(LEnvironment* environment,
 278                         Translation* translation,
 279                         LOperand* op,
 280                         bool is_tagged,
 281                         bool is_uint32,
 282                         int* object_index_pointer,
 283                         int* dematerialized_index_pointer);
 284
 285   void SaveCallerDoubles();
 286   void RestoreCallerDoubles();
 287
 288   // Code generation steps.  Returns true if code generation should continue.
 289   void GenerateBodyInstructionPre(LInstruction* instr) V8_OVERRIDE;
 290   bool GeneratePrologue();
 291   bool GenerateDeferredCode();
 292   bool GenerateDeoptJumpTable();
 293   bool GenerateSafepointTable();
 294
 295   // Generates the custom OSR entrypoint and sets the osr_pc_offset.
 296   void GenerateOsrPrologue();
 297
 298   enum SafepointMode {
 299     RECORD_SIMPLE_SAFEPOINT,
 300     RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS
 301   };
 302
 303   void CallCode(Handle<Code> code,
 304                 RelocInfo::Mode mode,
 305                 LInstruction* instr);
 306
 307   void CallCodeGeneric(Handle<Code> code,
 308                        RelocInfo::Mode mode,
 309                        LInstruction* instr,
 310                        SafepointMode safepoint_mode);
 311
 312   void CallRuntime(const Runtime::Function* function,
 313                    int num_arguments,
 314                    LInstruction* instr,
 315                    SaveFPRegsMode save_doubles = kDontSaveFPRegs);
 316
 317   void CallRuntime(Runtime::FunctionId id,
 318                    int num_arguments,
 319                    LInstruction* instr) {
 320     const Runtime::Function* function = Runtime::FunctionForId(id);
 321     CallRuntime(function, num_arguments, instr);
 322   }
 323
 324   void LoadContextFromDeferred(LOperand* context);
 325   void CallRuntimeFromDeferred(Runtime::FunctionId id,
 326                                int argc,
 327                                LInstruction* instr,
 328                                LOperand* context);
 329
 330   // Generate a direct call to a known function.
 331   // If the function is already loaded into x1 by the caller, function_reg may
 332   // be set to x1. Otherwise, it must be NoReg, and CallKnownFunction will
 333   // automatically load it.
 334   void CallKnownFunction(Handle<JSFunction> function,
 335                          int formal_parameter_count,
 336                          int arity,
 337                          LInstruction* instr,
 338                          Register function_reg = NoReg);
 339
 340   // Support for recording safepoint and position information.
 341   void RecordAndWritePosition(int position) V8_OVERRIDE;
 342   void RecordSafepoint(LPointerMap* pointers,
 343                        Safepoint::Kind kind,
 344                        int arguments,
 345                        Safepoint::DeoptMode mode);
 346   void RecordSafepoint(LPointerMap* pointers, Safepoint::DeoptMode mode);
 347   void RecordSafepoint(Safepoint::DeoptMode mode);
 348   void RecordSafepointWithRegisters(LPointerMap* pointers,
 349                                     int arguments,
 350                                     Safepoint::DeoptMode mode);
 351   void RecordSafepointWithRegistersAndDoubles(LPointerMap* pointers,
 352                                               int arguments,
 353                                               Safepoint::DeoptMode mode);
 354   void RecordSafepointWithLazyDeopt(LInstruction* instr,
 355                                     SafepointMode safepoint_mode);
 356
 357   void EnsureSpaceForLazyDeopt(int space_needed) V8_OVERRIDE;
 358
 359   ZoneList<LEnvironment*> deoptimizations_;
 360   ZoneList<Deoptimizer::JumpTableEntry*> deopt_jump_table_;
 361   ZoneList<Handle<Object> > deoptimization_literals_;
 362   int inlined_function_count_;
 363   Scope* const scope_;
 364   TranslationBuffer translations_;
 365   ZoneList<LDeferredCode*> deferred_;
 366   int osr_pc_offset_;
 367   bool frame_is_built_;
 368
 369   // Builder that keeps track of safepoints in the code. The table itself is
 370   // emitted at the end of the generated code.
 371   SafepointTableBuilder safepoints_;
 372
 373   // Compiler from a set of parallel moves to a sequential list of moves.
 374   LGapResolver resolver_;
 375
 376   Safepoint::Kind expected_safepoint_kind_;
 377
 378   // This flag is true when we are after a push (but before a call).
 379   // In this situation, jssp no longer references the end of the stack slots so,
 380   // we can only reference a stack slot via fp.
 381   bool after_push_argument_;
 382   // If we have inlined arguments, we are no longer able to use jssp because
 383   // jssp is modified and we never know if we are in a block after or before
 384   // the pop of the arguments (which restores jssp).
 385   bool inlined_arguments_;
 386
 387   int old_position_;
 388
 389   class PushSafepointRegistersScope BASE_EMBEDDED {
 390    public:
 391     PushSafepointRegistersScope(LCodeGen* codegen,
 392                                 Safepoint::Kind kind)
 393         : codegen_(codegen) {
 394       ASSERT(codegen_->info()->is_calling());
 395       ASSERT(codegen_->expected_safepoint_kind_ == Safepoint::kSimple);
 396       codegen_->expected_safepoint_kind_ = kind;
 397
 398       UseScratchRegisterScope temps(codegen_->masm_);
 399       // Preserve the value of lr which must be saved on the stack (the call to
 400       // the stub will clobber it).
 401       Register to_be_pushed_lr =
 402           temps.UnsafeAcquire(StoreRegistersStateStub::to_be_pushed_lr());
 403       codegen_->masm_->Mov(to_be_pushed_lr, lr);
 404       switch (codegen_->expected_safepoint_kind_) {
 405         case Safepoint::kWithRegisters: {
 406           StoreRegistersStateStub stub(codegen_->isolate(), kDontSaveFPRegs);
 407           codegen_->masm_->CallStub(&stub);
 408           break;
 409         }
 410         case Safepoint::kWithRegistersAndDoubles: {
 411           StoreRegistersStateStub stub(codegen_->isolate(), kSaveFPRegs);
 412           codegen_->masm_->CallStub(&stub);
 413           break;
 414         }
 415         default:
 416           UNREACHABLE();
 417       }
 418     }
 419
 420     ~PushSafepointRegistersScope() {
 421       Safepoint::Kind kind = codegen_->expected_safepoint_kind_;
 422       ASSERT((kind & Safepoint::kWithRegisters) != 0);
 423       switch (kind) {
 424         case Safepoint::kWithRegisters: {
 425           RestoreRegistersStateStub stub(codegen_->isolate(), kDontSaveFPRegs);
 426           codegen_->masm_->CallStub(&stub);
 427           break;
 428         }
 429         case Safepoint::kWithRegistersAndDoubles: {
 430           RestoreRegistersStateStub stub(codegen_->isolate(), kSaveFPRegs);
 431           codegen_->masm_->CallStub(&stub);
 432           break;
 433         }
 434         default:
 435           UNREACHABLE();
 436       }
 437       codegen_->expected_safepoint_kind_ = Safepoint::kSimple;
 438     }
 439
 440    private:
 441     LCodeGen* codegen_;
 442   };
 443
 444   friend class LDeferredCode;
 445   friend class SafepointGenerator;
 446   DISALLOW_COPY_AND_ASSIGN(LCodeGen);
 447 };
 448
 449
 450 class LDeferredCode: public ZoneObject {
 451  public:
 452   explicit LDeferredCode(LCodeGen* codegen)
 453       : codegen_(codegen),
 454         external_exit_(NULL),
 455         instruction_index_(codegen->current_instruction_) {
 456     codegen->AddDeferredCode(this);
 457   }
 458
 459   virtual ~LDeferredCode() { }
 460   virtual void Generate() = 0;
 461   virtual LInstruction* instr() = 0;
 462
 463   void SetExit(Label* exit) { external_exit_ = exit; }
 464   Label* entry() { return &entry_; }
 465   Label* exit() { return (external_exit_ != NULL) ? external_exit_ : &exit_; }
 466   int instruction_index() const { return instruction_index_; }
 467
 468  protected:
 469   LCodeGen* codegen() const { return codegen_; }
 470   MacroAssembler* masm() const { return codegen_->masm(); }
 471
 472  private:
 473   LCodeGen* codegen_;
 474   Label entry_;
 475   Label exit_;
 476   Label* external_exit_;
 477   int instruction_index_;
 478 };
 479
 480
 481 // This is the abstract class used by EmitBranchGeneric.
 482 // It is used to emit code for conditional branching. The Emit() function
 483 // emits code to branch when the condition holds and EmitInverted() emits
 484 // the branch when the inverted condition is verified.
 485 //
 486 // For actual examples of condition see the concrete implementation in
 487 // lithium-codegen-arm64.cc (e.g. BranchOnCondition, CompareAndBranch).
 488 class BranchGenerator BASE_EMBEDDED {
 489  public:
 490   explicit BranchGenerator(LCodeGen* codegen)
 491     : codegen_(codegen) { }
 492
 493   virtual ~BranchGenerator() { }
 494
 495   virtual void Emit(Label* label) const = 0;
 496   virtual void EmitInverted(Label* label) const = 0;
 497
 498  protected:
 499   MacroAssembler* masm() const { return codegen_->masm(); }
 500
 501   LCodeGen* codegen_;
 502 };
 503
 504 } }  // namespace v8::internal
 505
 506 #endif  // V8_ARM64_LITHIUM_CODEGEN_ARM64_H_