CSE2410 Fall 2014 Bounce

// Copyright 2012 the V8 project authors. All rights reserved.

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are

// met:

//

//     * Redistributions of source code must retain the above copyright

//       notice, this list of conditions and the following disclaimer.

//     * Redistributions in binary form must reproduce the above

//       copyright notice, this list of conditions and the following

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//       with the distribution.

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//       contributors may be used to endorse or promote products derived

//       from this software without specific prior written permission.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

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#ifndef V8_ARM_LITHIUM_CODEGEN_ARM_H_

#define V8_ARM_LITHIUM_CODEGEN_ARM_H_

#include "arm/lithium-arm.h"

#include "arm/lithium-gap-resolver-arm.h"

#include "deoptimizer.h"

#include "lithium-codegen.h"

#include "safepoint-table.h"

#include "scopes.h"

#include "v8utils.h"

namespace v8 {

namespace internal {

// Forward declarations.

class LDeferredCode;

class SafepointGenerator;

class LCodeGen: public LCodeGenBase {

 public:

  LCodeGen(LChunk* chunk, MacroAssembler* assembler, CompilationInfo* info)

      : LCodeGenBase(chunk, assembler, info),

        deoptimizations_(4, info->zone()),

        deopt_jump_table_(4, info->zone()),

        deoptimization_literals_(8, info->zone()),

        inlined_function_count_(0),

        scope_(info->scope()),

        translations_(info->zone()),

        deferred_(8, info->zone()),

        osr_pc_offset_(-1),

        frame_is_built_(false),

        safepoints_(info->zone()),

        resolver_(this),

        expected_safepoint_kind_(Safepoint::kSimple) {

    PopulateDeoptimizationLiteralsWithInlinedFunctions();

  }

  int LookupDestination(int block_id) const {

    return chunk()->LookupDestination(block_id);

  }

  bool IsNextEmittedBlock(int block_id) const {

    return LookupDestination(block_id) == GetNextEmittedBlock();

  }

  bool NeedsEagerFrame() const {

    return GetStackSlotCount() > 0 ||

        info()->is_non_deferred_calling() ||

        !info()->IsStub() ||

        info()->requires_frame();

  }

  bool NeedsDeferredFrame() const {

    return !NeedsEagerFrame() && info()->is_deferred_calling();

  }

  LinkRegisterStatus GetLinkRegisterState() const {

    return frame_is_built_ ? kLRHasBeenSaved : kLRHasNotBeenSaved;

  }

  // Support for converting LOperands to assembler types.

  // LOperand must be a register.

  Register ToRegister(LOperand* op) const;

  // LOperand is loaded into scratch, unless already a register.

  Register EmitLoadRegister(LOperand* op, Register scratch);

  // LOperand must be a double register.

  DwVfpRegister ToDoubleRegister(LOperand* op) const;

  // LOperand is loaded into dbl_scratch, unless already a double register.

  DwVfpRegister EmitLoadDoubleRegister(LOperand* op,

                                       SwVfpRegister flt_scratch,

                                       DwVfpRegister dbl_scratch);

  int32_t ToRepresentation(LConstantOperand* op, const Representation& r) const;

  int32_t ToInteger32(LConstantOperand* op) const;

  Smi* ToSmi(LConstantOperand* op) const;

  double ToDouble(LConstantOperand* op) const;

  Operand ToOperand(LOperand* op);

  MemOperand ToMemOperand(LOperand* op) const;

  // Returns a MemOperand pointing to the high word of a DoubleStackSlot.

  MemOperand ToHighMemOperand(LOperand* op) const;

  bool IsInteger32(LConstantOperand* op) const;

  bool IsSmi(LConstantOperand* op) const;

  Handle<Object> ToHandle(LConstantOperand* op) const;

  // Try to generate code for the entire chunk, but it may fail if the

  // chunk contains constructs we cannot handle. Returns true if the

  // code generation attempt succeeded.

  bool GenerateCode();

  // Finish the code by setting stack height, safepoint, and bailout

  // information on it.

  void FinishCode(Handle<Code> code);

  // Deferred code support.

  void DoDeferredNumberTagD(LNumberTagD* instr);

  enum IntegerSignedness { SIGNED_INT32, UNSIGNED_INT32 };

  void DoDeferredNumberTagI(LInstruction* instr,

                            LOperand* value,

                            IntegerSignedness signedness);

  void DoDeferredTaggedToI(LTaggedToI* instr);

  void DoDeferredMathAbsTaggedHeapNumber(LMathAbs* instr);

  void DoDeferredStackCheck(LStackCheck* instr);

  void DoDeferredStringCharCodeAt(LStringCharCodeAt* instr);

  void DoDeferredStringCharFromCode(LStringCharFromCode* instr);

  void DoDeferredAllocate(LAllocate* instr);

  void DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,

                                       Label* map_check);

  void DoDeferredInstanceMigration(LCheckMaps* instr, Register object);

  // Parallel move support.

  void DoParallelMove(LParallelMove* move);

  void DoGap(LGap* instr);

  MemOperand PrepareKeyedOperand(Register key,

                                 Register base,

                                 bool key_is_constant,

                                 int constant_key,

                                 int element_size,

                                 int shift_size,

                                 int additional_index,

                                 int additional_offset);

  // Emit frame translation commands for an environment.

  void WriteTranslation(LEnvironment* environment, Translation* translation);

  // Declare methods that deal with the individual node types.

#define DECLARE_DO(type) void Do##type(L##type* node);

  LITHIUM_CONCRETE_INSTRUCTION_LIST(DECLARE_DO)

#undef DECLARE_DO

 private:

  StrictModeFlag strict_mode_flag() const {

    return info()->is_classic_mode() ? kNonStrictMode : kStrictMode;

  }

  Scope* scope() const { return scope_; }

  Register scratch0() { return r9; }

  LowDwVfpRegister double_scratch0() { return kScratchDoubleReg; }

  LInstruction* GetNextInstruction();

  void EmitClassOfTest(Label* if_true,

                       Label* if_false,

                       Handle<String> class_name,

                       Register input,

                       Register temporary,

                       Register temporary2);

  int GetStackSlotCount() const { return chunk()->spill_slot_count(); }

  void Abort(BailoutReason reason);

  void AddDeferredCode(LDeferredCode* code) { deferred_.Add(code, zone()); }

  // Code generation passes.  Returns true if code generation should

  // continue.

  bool GeneratePrologue();

  bool GenerateDeferredCode();

  bool GenerateDeoptJumpTable();

  bool GenerateSafepointTable();

  // Generates the custom OSR entrypoint and sets the osr_pc_offset.

  void GenerateOsrPrologue();

  enum SafepointMode {

    RECORD_SIMPLE_SAFEPOINT,

    RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS

  };

  void CallCode(

      Handle<Code> code,

      RelocInfo::Mode mode,

      LInstruction* instr,

      TargetAddressStorageMode storage_mode = CAN_INLINE_TARGET_ADDRESS);

  void CallCodeGeneric(

      Handle<Code> code,

      RelocInfo::Mode mode,

      LInstruction* instr,

      SafepointMode safepoint_mode,

      TargetAddressStorageMode storage_mode = CAN_INLINE_TARGET_ADDRESS);

  void CallRuntime(const Runtime::Function* function,

                   int num_arguments,

                   LInstruction* instr,

                   SaveFPRegsMode save_doubles = kDontSaveFPRegs);

  void CallRuntime(Runtime::FunctionId id,

                   int num_arguments,

                   LInstruction* instr) {

    const Runtime::Function* function = Runtime::FunctionForId(id);

    CallRuntime(function, num_arguments, instr);

  }

  void LoadContextFromDeferred(LOperand* context);

  void CallRuntimeFromDeferred(Runtime::FunctionId id,

                               int argc,

                               LInstruction* instr,

                               LOperand* context);

  enum R1State {

    R1_UNINITIALIZED,

    R1_CONTAINS_TARGET

  };

  // Generate a direct call to a known function.  Expects the function

  // to be in r1.

  void CallKnownFunction(Handle<JSFunction> function,

                         int formal_parameter_count,

                         int arity,

                         LInstruction* instr,

                         CallKind call_kind,

                         R1State r1_state);

  void RecordSafepointWithLazyDeopt(LInstruction* instr,

                                    SafepointMode safepoint_mode);

  void RegisterEnvironmentForDeoptimization(LEnvironment* environment,

                                            Safepoint::DeoptMode mode);

  void DeoptimizeIf(Condition condition,

                    LEnvironment* environment,

                    Deoptimizer::BailoutType bailout_type);

  void DeoptimizeIf(Condition condition, LEnvironment* environment);

  void ApplyCheckIf(Condition condition, LBoundsCheck* check);

  void AddToTranslation(LEnvironment* environment,

                        Translation* translation,

                        LOperand* op,

                        bool is_tagged,

                        bool is_uint32,

                        int* object_index_pointer,

                        int* dematerialized_index_pointer);

  void RegisterDependentCodeForEmbeddedMaps(Handle<Code> code);

  void PopulateDeoptimizationData(Handle<Code> code);

  int DefineDeoptimizationLiteral(Handle<Object> literal);

  void PopulateDeoptimizationLiteralsWithInlinedFunctions();

  Register ToRegister(int index) const;

  DwVfpRegister ToDoubleRegister(int index) const;

  void EmitIntegerMathAbs(LMathAbs* instr);

  // Support for recording safepoint and position information.

  void RecordSafepoint(LPointerMap* pointers,

                       Safepoint::Kind kind,

                       int arguments,

                       Safepoint::DeoptMode mode);

  void RecordSafepoint(LPointerMap* pointers, Safepoint::DeoptMode mode);

  void RecordSafepoint(Safepoint::DeoptMode mode);

  void RecordSafepointWithRegisters(LPointerMap* pointers,

                                    int arguments,

                                    Safepoint::DeoptMode mode);

  void RecordSafepointWithRegistersAndDoubles(LPointerMap* pointers,

                                              int arguments,

                                              Safepoint::DeoptMode mode);

  void RecordAndWritePosition(int position) V8_OVERRIDE;

  static Condition TokenToCondition(Token::Value op, bool is_unsigned);

  void EmitGoto(int block);

  template<class InstrType>

  void EmitBranch(InstrType instr, Condition condition);

  template<class InstrType>

  void EmitFalseBranch(InstrType instr, Condition condition);

  void EmitNumberUntagD(Register input,

                        DwVfpRegister result,

                        bool allow_undefined_as_nan,

                        bool deoptimize_on_minus_zero,

                        LEnvironment* env,

                        NumberUntagDMode mode);

  // Emits optimized code for typeof x == "y".  Modifies input register.

  // Returns the condition on which a final split to

  // true and false label should be made, to optimize fallthrough.

  Condition EmitTypeofIs(Label* true_label,

                         Label* false_label,

                         Register input,

                         Handle<String> type_name);

  // Emits optimized code for %_IsObject(x).  Preserves input register.

  // Returns the condition on which a final split to

  // true and false label should be made, to optimize fallthrough.

  Condition EmitIsObject(Register input,

                         Register temp1,

                         Label* is_not_object,

                         Label* is_object);

  // Emits optimized code for %_IsString(x).  Preserves input register.

  // Returns the condition on which a final split to

  // true and false label should be made, to optimize fallthrough.

  Condition EmitIsString(Register input,

                         Register temp1,

                         Label* is_not_string,

                         SmiCheck check_needed);

  // Emits optimized code for %_IsConstructCall().

  // Caller should branch on equal condition.

  void EmitIsConstructCall(Register temp1, Register temp2);

  // Emits optimized code to deep-copy the contents of statically known

  // object graphs (e.g. object literal boilerplate).

  void EmitDeepCopy(Handle<JSObject> object,

                    Register result,

                    Register source,

                    int* offset,

                    AllocationSiteMode mode);

  // Emit optimized code for integer division.

  // Inputs are signed.

  // All registers are clobbered.

  // If 'remainder' is no_reg, it is not computed.

  void EmitSignedIntegerDivisionByConstant(Register result,

                                           Register dividend,

                                           int32_t divisor,

                                           Register remainder,

                                           Register scratch,

                                           LEnvironment* environment);

  void EnsureSpaceForLazyDeopt(int space_needed) V8_OVERRIDE;

  void DoLoadKeyedExternalArray(LLoadKeyed* instr);

  void DoLoadKeyedFixedDoubleArray(LLoadKeyed* instr);

  void DoLoadKeyedFixedArray(LLoadKeyed* instr);

  void DoStoreKeyedExternalArray(LStoreKeyed* instr);

  void DoStoreKeyedFixedDoubleArray(LStoreKeyed* instr);

  void DoStoreKeyedFixedArray(LStoreKeyed* instr);

  ZoneList<LEnvironment*> deoptimizations_;

  ZoneList<Deoptimizer::JumpTableEntry> deopt_jump_table_;

  ZoneList<Handle<Object> > deoptimization_literals_;

  int inlined_function_count_;

  Scope* const scope_;

  TranslationBuffer translations_;

  ZoneList<LDeferredCode*> deferred_;

  int osr_pc_offset_;

  bool frame_is_built_;

  // Builder that keeps track of safepoints in the code. The table

  // itself is emitted at the end of the generated code.

  SafepointTableBuilder safepoints_;

  // Compiler from a set of parallel moves to a sequential list of moves.

  LGapResolver resolver_;

  Safepoint::Kind expected_safepoint_kind_;

  class PushSafepointRegistersScope V8_FINAL BASE_EMBEDDED {

   public:

    PushSafepointRegistersScope(LCodeGen* codegen,

                                Safepoint::Kind kind)

        : codegen_(codegen) {

      ASSERT(codegen_->info()->is_calling());

      ASSERT(codegen_->expected_safepoint_kind_ == Safepoint::kSimple);

      codegen_->expected_safepoint_kind_ = kind;

      switch (codegen_->expected_safepoint_kind_) {

        case Safepoint::kWithRegisters:

          codegen_->masm_->PushSafepointRegisters();

          break;

        case Safepoint::kWithRegistersAndDoubles:

          codegen_->masm_->PushSafepointRegistersAndDoubles();

          break;

        default:

          UNREACHABLE();

      }

    }

    ~PushSafepointRegistersScope() {

      Safepoint::Kind kind = codegen_->expected_safepoint_kind_;

      ASSERT((kind & Safepoint::kWithRegisters) != 0);

      switch (kind) {

        case Safepoint::kWithRegisters:

          codegen_->masm_->PopSafepointRegisters();

          break;

        case Safepoint::kWithRegistersAndDoubles:

          codegen_->masm_->PopSafepointRegistersAndDoubles();

          break;

        default:

          UNREACHABLE();

      }

      codegen_->expected_safepoint_kind_ = Safepoint::kSimple;

    }

   private:

    LCodeGen* codegen_;

  };

  friend class LDeferredCode;

  friend class LEnvironment;

  friend class SafepointGenerator;

  DISALLOW_COPY_AND_ASSIGN(LCodeGen);

};

class LDeferredCode : public ZoneObject {

 public:

  explicit LDeferredCode(LCodeGen* codegen)

      : codegen_(codegen),

        external_exit_(NULL),

        instruction_index_(codegen->current_instruction_) {

    codegen->AddDeferredCode(this);

  }

  virtual ~LDeferredCode() {}

  virtual void Generate() = 0;

  virtual LInstruction* instr() = 0;

  void SetExit(Label* exit) { external_exit_ = exit; }

  Label* entry() { return &entry_; }

  Label* exit() { return external_exit_ != NULL ? external_exit_ : &exit_; }

  int instruction_index() const { return instruction_index_; }

 protected:

  LCodeGen* codegen() const { return codegen_; }

  MacroAssembler* masm() const { return codegen_->masm(); }

 private:

  LCodeGen* codegen_;

  Label entry_;

  Label exit_;

  Label* external_exit_;

  int instruction_index_;

};

} }  // namespace v8::internal

#endif  // V8_ARM_LITHIUM_CODEGEN_ARM_H_