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

//       disclaimer in the documentation and/or other materials provided

//       with the distribution.

//     * Neither the name of Google Inc. nor the names of its

//       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

// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifndef V8_IA32_LITHIUM_CODEGEN_IA32_H_

#define V8_IA32_LITHIUM_CODEGEN_IA32_H_

#include "ia32/lithium-ia32.h"

#include "checks.h"

#include "deoptimizer.h"

#include "ia32/lithium-gap-resolver-ia32.h"

#include "lithium-codegen.h"

#include "safepoint-table.h"

#include "scopes.h"

#include "v8utils.h"

namespace v8 {

namespace internal {

// Forward declarations.

class LDeferredCode;

class LGapNode;

class SafepointGenerator;

class LCodeGen: public LCodeGenBase {

 public:

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

      : LCodeGenBase(chunk, assembler, info),

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

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

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

        inlined_function_count_(0),

        scope_(info->scope()),

        translations_(info->zone()),

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

        dynamic_frame_alignment_(false),

        support_aligned_spilled_doubles_(false),

        osr_pc_offset_(-1),

        frame_is_built_(false),

        x87_stack_(assembler),

        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();

  }

  // Support for converting LOperands to assembler types.

  Operand ToOperand(LOperand* op) const;

  Register ToRegister(LOperand* op) const;

  XMMRegister ToDoubleRegister(LOperand* op) const;

  X87Register ToX87Register(LOperand* op) const;

  bool IsInteger32(LConstantOperand* op) const;

  bool IsSmi(LConstantOperand* op) const;

  Immediate ToImmediate(LOperand* op, const Representation& r) const {

    return Immediate(ToRepresentation(LConstantOperand::cast(op), r));

  }

  double ToDouble(LConstantOperand* op) const;

  // Support for non-sse2 (x87) floating point stack handling.

  // These functions maintain the mapping of physical stack registers to our

  // virtual registers between instructions.

  enum X87OperandType { kX87DoubleOperand, kX87FloatOperand, kX87IntOperand };

  void X87Mov(X87Register reg, Operand src,

      X87OperandType operand = kX87DoubleOperand);

  void X87Mov(Operand src, X87Register reg,

      X87OperandType operand = kX87DoubleOperand);

  void X87PrepareBinaryOp(

      X87Register left, X87Register right, X87Register result);

  void X87LoadForUsage(X87Register reg);

  void X87LoadForUsage(X87Register reg1, X87Register reg2);

  void X87PrepareToWrite(X87Register reg) { x87_stack_.PrepareToWrite(reg); }

  void X87CommitWrite(X87Register reg) { x87_stack_.CommitWrite(reg); }

  void X87Fxch(X87Register reg, int other_slot = 0) {

    x87_stack_.Fxch(reg, other_slot);

  }

  void X87Free(X87Register reg) {

    x87_stack_.Free(reg);

  }

  bool X87StackEmpty() {

    return x87_stack_.depth() == 0;

  }

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

  // The operand denoting the second word (the one with a higher address) of

  // a double stack slot.

  Operand HighOperand(LOperand* op);

  // 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, Label* done);

  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);

  // Emit frame translation commands for an environment.

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

  void EnsureRelocSpaceForDeoptimization();

  // 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_; }

  XMMRegister double_scratch0() const { return xmm0; }

  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.

  void GenerateBodyInstructionPre(LInstruction* instr) V8_OVERRIDE;

  void GenerateBodyInstructionPost(LInstruction* instr) V8_OVERRIDE;

  bool GeneratePrologue();

  bool GenerateDeferredCode();

  bool GenerateJumpTable();

  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);

  void CallCodeGeneric(Handle<Code> code,

                       RelocInfo::Mode mode,

                       LInstruction* instr,

                       SafepointMode safepoint_mode);

  void CallRuntime(const Runtime::Function* fun,

                   int argc,

                   LInstruction* instr,

                   SaveFPRegsMode save_doubles = kDontSaveFPRegs);

  void CallRuntime(Runtime::FunctionId id,

                   int argc,

                   LInstruction* instr) {

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

    CallRuntime(function, argc, instr);

  }

  void CallRuntimeFromDeferred(Runtime::FunctionId id,

                               int argc,

                               LInstruction* instr,

                               LOperand* context);

  void LoadContextFromDeferred(LOperand* context);

  enum EDIState {

    EDI_UNINITIALIZED,

    EDI_CONTAINS_TARGET

  };

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

  // to be in edi.

  void CallKnownFunction(Handle<JSFunction> function,

                         int formal_parameter_count,

                         int arity,

                         LInstruction* instr,

                         CallKind call_kind,

                         EDIState edi_state);

  void RecordSafepointWithLazyDeopt(LInstruction* instr,

                                    SafepointMode safepoint_mode);

  void RegisterEnvironmentForDeoptimization(LEnvironment* environment,

                                            Safepoint::DeoptMode mode);

  void DeoptimizeIf(Condition cc,

                    LEnvironment* environment,

                    Deoptimizer::BailoutType bailout_type);

  void DeoptimizeIf(Condition cc, LEnvironment* environment);

  void ApplyCheckIf(Condition cc, 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;

  XMMRegister ToDoubleRegister(int index) const;

  X87Register ToX87Register(int index) const;

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

  int32_t ToInteger32(LConstantOperand* op) const;

  ExternalReference ToExternalReference(LConstantOperand* op) const;

  Operand BuildFastArrayOperand(LOperand* elements_pointer,

                                LOperand* key,

                                Representation key_representation,

                                ElementsKind elements_kind,

                                uint32_t offset,

                                uint32_t additional_index = 0);

  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 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 cc);

  template<class InstrType>

  void EmitFalseBranch(InstrType instr, Condition cc);

  void EmitNumberUntagD(

      Register input,

      Register temp,

      XMMRegister result,

      bool allow_undefined_as_nan,

      bool deoptimize_on_minus_zero,

      LEnvironment* env,

      NumberUntagDMode mode = NUMBER_CANDIDATE_IS_ANY_TAGGED);

  void EmitNumberUntagDNoSSE2(

      Register input,

      Register temp,

      X87Register res_reg,

      bool allow_undefined_as_nan,

      bool deoptimize_on_minus_zero,

      LEnvironment* env,

      NumberUntagDMode mode = NUMBER_CANDIDATE_IS_ANY_TAGGED);

  // 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 temp);

  // 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);

  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);

  void EmitReturn(LReturn* instr, bool dynamic_frame_alignment);

  // Emits code for pushing either a tagged constant, a (non-double)

  // register, or a stack slot operand.

  void EmitPushTaggedOperand(LOperand* operand);

  void X87Fld(Operand src, X87OperandType opts);

  void EmitFlushX87ForDeopt();

  void FlushX87StackIfNecessary(LInstruction* instr) {

    x87_stack_.FlushIfNecessary(instr, this);

  }

  friend class LGapResolver;

#ifdef _MSC_VER

  // On windows, you may not access the stack more than one page below

  // the most recently mapped page. To make the allocated area randomly

  // accessible, we write an arbitrary value to each page in range

  // esp + offset - page_size .. esp in turn.

  void MakeSureStackPagesMapped(int offset);

#endif

  ZoneList<LEnvironment*> deoptimizations_;

  ZoneList<Deoptimizer::JumpTableEntry> jump_table_;

  ZoneList<Handle<Object> > deoptimization_literals_;

  int inlined_function_count_;

  Scope* const scope_;

  TranslationBuffer translations_;

  ZoneList<LDeferredCode*> deferred_;

  bool dynamic_frame_alignment_;

  bool support_aligned_spilled_doubles_;

  int osr_pc_offset_;

  bool frame_is_built_;

  class X87Stack {

   public:

    explicit X87Stack(MacroAssembler* masm)

        : stack_depth_(0), is_mutable_(true), masm_(masm) { }

    explicit X87Stack(const X87Stack& other)

        : stack_depth_(other.stack_depth_), is_mutable_(false), masm_(masm()) {

      for (int i = 0; i < stack_depth_; i++) {

        stack_[i] = other.stack_[i];

      }

    }

    bool operator==(const X87Stack& other) const {

      if (stack_depth_ != other.stack_depth_) return false;

      for (int i = 0; i < stack_depth_; i++) {

        if (!stack_[i].is(other.stack_[i])) return false;

      }

      return true;

    }

    bool Contains(X87Register reg);

    void Fxch(X87Register reg, int other_slot = 0);

    void Free(X87Register reg);

    void PrepareToWrite(X87Register reg);

    void CommitWrite(X87Register reg);

    void FlushIfNecessary(LInstruction* instr, LCodeGen* cgen);

    void LeavingBlock(int current_block_id, LGoto* goto_instr);

    int depth() const { return stack_depth_; }

    void pop() {

      ASSERT(is_mutable_);

      stack_depth_--;

    }

    void push(X87Register reg) {

      ASSERT(is_mutable_);

      ASSERT(stack_depth_ < X87Register::kNumAllocatableRegisters);

      stack_[stack_depth_] = reg;

      stack_depth_++;

    }

    MacroAssembler* masm() const { return masm_; }

   private:

    int ArrayIndex(X87Register reg);

    int st2idx(int pos);

    X87Register stack_[X87Register::kNumAllocatableRegisters];

    int stack_depth_;

    bool is_mutable_;

    MacroAssembler* masm_;

  };

  X87Stack x87_stack_;

  // 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:

    explicit PushSafepointRegistersScope(LCodeGen* codegen)

        : codegen_(codegen) {

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

      codegen_->masm_->PushSafepointRegisters();

      codegen_->expected_safepoint_kind_ = Safepoint::kWithRegisters;

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

    }

    ~PushSafepointRegistersScope() {

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

      codegen_->masm_->PopSafepointRegisters();

      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, const LCodeGen::X87Stack& x87_stack)

      : codegen_(codegen),

        external_exit_(NULL),

        instruction_index_(codegen->current_instruction_),

        x87_stack_(x87_stack) {

    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_; }

  Label* done() { return codegen_->NeedsDeferredFrame() ? &done_ : exit(); }

  int instruction_index() const { return instruction_index_; }

  const LCodeGen::X87Stack& x87_stack() const { return x87_stack_; }

 protected:

  LCodeGen* codegen() const { return codegen_; }

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

 private:

  LCodeGen* codegen_;

  Label entry_;

  Label exit_;

  Label* external_exit_;

  Label done_;

  int instruction_index_;

  LCodeGen::X87Stack x87_stack_;

};

} }  // namespace v8::internal

#endif  // V8_IA32_LITHIUM_CODEGEN_IA32_H_