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      1 // Copyright 2012 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_X64_LITHIUM_CODEGEN_X64_H_
      6 #define V8_X64_LITHIUM_CODEGEN_X64_H_
      7 
      8 #include "src/x64/lithium-x64.h"
      9 
     10 #include "src/checks.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 #include "src/x64/lithium-gap-resolver-x64.h"
     17 
     18 namespace v8 {
     19 namespace internal {
     20 
     21 // Forward declarations.
     22 class LDeferredCode;
     23 class SafepointGenerator;
     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     PopulateDeoptimizationLiteralsWithInlinedFunctions();
     42   }
     43 
     44   int LookupDestination(int block_id) const {
     45     return chunk()->LookupDestination(block_id);
     46   }
     47 
     48   bool IsNextEmittedBlock(int block_id) const {
     49     return LookupDestination(block_id) == GetNextEmittedBlock();
     50   }
     51 
     52   bool NeedsEagerFrame() const {
     53     return GetStackSlotCount() > 0 ||
     54         info()->is_non_deferred_calling() ||
     55         !info()->IsStub() ||
     56         info()->requires_frame();
     57   }
     58   bool NeedsDeferredFrame() const {
     59     return !NeedsEagerFrame() && info()->is_deferred_calling();
     60   }
     61 
     62   // Support for converting LOperands to assembler types.
     63   Register ToRegister(LOperand* op) const;
     64   XMMRegister ToDoubleRegister(LOperand* op) const;
     65   bool IsInteger32Constant(LConstantOperand* op) const;
     66   bool IsDehoistedKeyConstant(LConstantOperand* op) const;
     67   bool IsSmiConstant(LConstantOperand* op) const;
     68   int32_t ToRepresentation(LConstantOperand* op, const Representation& r) const;
     69   int32_t ToInteger32(LConstantOperand* op) const;
     70   Smi* ToSmi(LConstantOperand* op) const;
     71   double ToDouble(LConstantOperand* op) const;
     72   ExternalReference ToExternalReference(LConstantOperand* op) const;
     73   Handle<Object> ToHandle(LConstantOperand* op) const;
     74   Operand ToOperand(LOperand* op) const;
     75 
     76   // Try to generate code for the entire chunk, but it may fail if the
     77   // chunk contains constructs we cannot handle. Returns true if the
     78   // code generation attempt succeeded.
     79   bool GenerateCode();
     80 
     81   // Finish the code by setting stack height, safepoint, and bailout
     82   // information on it.
     83   void FinishCode(Handle<Code> code);
     84 
     85   // Deferred code support.
     86   void DoDeferredNumberTagD(LNumberTagD* instr);
     87 
     88   enum IntegerSignedness { SIGNED_INT32, UNSIGNED_INT32 };
     89   void DoDeferredNumberTagIU(LInstruction* instr,
     90                              LOperand* value,
     91                              LOperand* temp1,
     92                              LOperand* temp2,
     93                              IntegerSignedness signedness);
     94 
     95   void DoDeferredTaggedToI(LTaggedToI* instr, Label* done);
     96   void DoDeferredMathAbsTaggedHeapNumber(LMathAbs* instr);
     97   void DoDeferredStackCheck(LStackCheck* instr);
     98   void DoDeferredStringCharCodeAt(LStringCharCodeAt* instr);
     99   void DoDeferredStringCharFromCode(LStringCharFromCode* instr);
    100   void DoDeferredAllocate(LAllocate* instr);
    101   void DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
    102                                        Label* map_check);
    103   void DoDeferredInstanceMigration(LCheckMaps* instr, Register object);
    104   void DoDeferredLoadMutableDouble(LLoadFieldByIndex* instr,
    105                                    Register object,
    106                                    Register index);
    107 
    108 // Parallel move support.
    109   void DoParallelMove(LParallelMove* move);
    110   void DoGap(LGap* instr);
    111 
    112   // Emit frame translation commands for an environment.
    113   void WriteTranslation(LEnvironment* environment, Translation* translation);
    114 
    115   // Declare methods that deal with the individual node types.
    116 #define DECLARE_DO(type) void Do##type(L##type* node);
    117   LITHIUM_CONCRETE_INSTRUCTION_LIST(DECLARE_DO)
    118 #undef DECLARE_DO
    119 
    120  private:
    121   StrictMode strict_mode() const { return info()->strict_mode(); }
    122 
    123   LPlatformChunk* chunk() const { return chunk_; }
    124   Scope* scope() const { return scope_; }
    125   HGraph* graph() const { return chunk()->graph(); }
    126 
    127   XMMRegister double_scratch0() const { return xmm0; }
    128 
    129   void EmitClassOfTest(Label* if_true,
    130                        Label* if_false,
    131                        Handle<String> class_name,
    132                        Register input,
    133                        Register temporary,
    134                        Register scratch);
    135 
    136   int GetStackSlotCount() const { return chunk()->spill_slot_count(); }
    137 
    138   void AddDeferredCode(LDeferredCode* code) { deferred_.Add(code, zone()); }
    139 
    140 
    141   void SaveCallerDoubles();
    142   void RestoreCallerDoubles();
    143 
    144   // Code generation passes.  Returns true if code generation should
    145   // continue.
    146   void GenerateBodyInstructionPre(LInstruction* instr) V8_OVERRIDE;
    147   void GenerateBodyInstructionPost(LInstruction* instr) V8_OVERRIDE;
    148   bool GeneratePrologue();
    149   bool GenerateDeferredCode();
    150   bool GenerateJumpTable();
    151   bool GenerateSafepointTable();
    152 
    153   // Generates the custom OSR entrypoint and sets the osr_pc_offset.
    154   void GenerateOsrPrologue();
    155 
    156   enum SafepointMode {
    157     RECORD_SIMPLE_SAFEPOINT,
    158     RECORD_SAFEPOINT_WITH_REGISTERS
    159   };
    160 
    161   void CallCodeGeneric(Handle<Code> code,
    162                        RelocInfo::Mode mode,
    163                        LInstruction* instr,
    164                        SafepointMode safepoint_mode,
    165                        int argc);
    166 
    167 
    168   void CallCode(Handle<Code> code,
    169                 RelocInfo::Mode mode,
    170                 LInstruction* instr);
    171 
    172   void CallRuntime(const Runtime::Function* function,
    173                    int num_arguments,
    174                    LInstruction* instr,
    175                    SaveFPRegsMode save_doubles = kDontSaveFPRegs);
    176 
    177   void CallRuntime(Runtime::FunctionId id,
    178                    int num_arguments,
    179                    LInstruction* instr) {
    180     const Runtime::Function* function = Runtime::FunctionForId(id);
    181     CallRuntime(function, num_arguments, instr);
    182   }
    183 
    184   void CallRuntimeFromDeferred(Runtime::FunctionId id,
    185                                int argc,
    186                                LInstruction* instr,
    187                                LOperand* context);
    188 
    189   void LoadContextFromDeferred(LOperand* context);
    190 
    191   enum RDIState {
    192     RDI_UNINITIALIZED,
    193     RDI_CONTAINS_TARGET
    194   };
    195 
    196   // Generate a direct call to a known function.  Expects the function
    197   // to be in rdi.
    198   void CallKnownFunction(Handle<JSFunction> function,
    199                          int formal_parameter_count,
    200                          int arity,
    201                          LInstruction* instr,
    202                          RDIState rdi_state);
    203 
    204   void RecordSafepointWithLazyDeopt(LInstruction* instr,
    205                                     SafepointMode safepoint_mode,
    206                                     int argc);
    207   void RegisterEnvironmentForDeoptimization(LEnvironment* environment,
    208                                             Safepoint::DeoptMode mode);
    209   void DeoptimizeIf(Condition cc,
    210                     LEnvironment* environment,
    211                     Deoptimizer::BailoutType bailout_type);
    212   void DeoptimizeIf(Condition cc, LEnvironment* environment);
    213 
    214   bool DeoptEveryNTimes() {
    215     return FLAG_deopt_every_n_times != 0 && !info()->IsStub();
    216   }
    217 
    218   void AddToTranslation(LEnvironment* environment,
    219                         Translation* translation,
    220                         LOperand* op,
    221                         bool is_tagged,
    222                         bool is_uint32,
    223                         int* object_index_pointer,
    224                         int* dematerialized_index_pointer);
    225   void PopulateDeoptimizationData(Handle<Code> code);
    226   int DefineDeoptimizationLiteral(Handle<Object> literal);
    227 
    228   void PopulateDeoptimizationLiteralsWithInlinedFunctions();
    229 
    230   Register ToRegister(int index) const;
    231   XMMRegister ToDoubleRegister(int index) const;
    232   Operand BuildFastArrayOperand(
    233       LOperand* elements_pointer,
    234       LOperand* key,
    235       Representation key_representation,
    236       ElementsKind elements_kind,
    237       uint32_t base_offset);
    238 
    239   Operand BuildSeqStringOperand(Register string,
    240                                 LOperand* index,
    241                                 String::Encoding encoding);
    242 
    243   void EmitIntegerMathAbs(LMathAbs* instr);
    244   void EmitSmiMathAbs(LMathAbs* instr);
    245 
    246   // Support for recording safepoint and position information.
    247   void RecordSafepoint(LPointerMap* pointers,
    248                        Safepoint::Kind kind,
    249                        int arguments,
    250                        Safepoint::DeoptMode mode);
    251   void RecordSafepoint(LPointerMap* pointers, Safepoint::DeoptMode mode);
    252   void RecordSafepoint(Safepoint::DeoptMode mode);
    253   void RecordSafepointWithRegisters(LPointerMap* pointers,
    254                                     int arguments,
    255                                     Safepoint::DeoptMode mode);
    256   void RecordAndWritePosition(int position) V8_OVERRIDE;
    257 
    258   static Condition TokenToCondition(Token::Value op, bool is_unsigned);
    259   void EmitGoto(int block);
    260 
    261   // EmitBranch expects to be the last instruction of a block.
    262   template<class InstrType>
    263   void EmitBranch(InstrType instr, Condition cc);
    264   template<class InstrType>
    265   void EmitFalseBranch(InstrType instr, Condition cc);
    266   void EmitNumberUntagD(
    267       Register input,
    268       XMMRegister result,
    269       bool allow_undefined_as_nan,
    270       bool deoptimize_on_minus_zero,
    271       LEnvironment* env,
    272       NumberUntagDMode mode = NUMBER_CANDIDATE_IS_ANY_TAGGED);
    273 
    274   // Emits optimized code for typeof x == "y".  Modifies input register.
    275   // Returns the condition on which a final split to
    276   // true and false label should be made, to optimize fallthrough.
    277   Condition EmitTypeofIs(LTypeofIsAndBranch* instr, Register input);
    278 
    279   // Emits optimized code for %_IsObject(x).  Preserves input register.
    280   // Returns the condition on which a final split to
    281   // true and false label should be made, to optimize fallthrough.
    282   Condition EmitIsObject(Register input,
    283                          Label* is_not_object,
    284                          Label* is_object);
    285 
    286   // Emits optimized code for %_IsString(x).  Preserves input register.
    287   // Returns the condition on which a final split to
    288   // true and false label should be made, to optimize fallthrough.
    289   Condition EmitIsString(Register input,
    290                          Register temp1,
    291                          Label* is_not_string,
    292                          SmiCheck check_needed);
    293 
    294   // Emits optimized code for %_IsConstructCall().
    295   // Caller should branch on equal condition.
    296   void EmitIsConstructCall(Register temp);
    297 
    298   // Emits code for pushing either a tagged constant, a (non-double)
    299   // register, or a stack slot operand.
    300   void EmitPushTaggedOperand(LOperand* operand);
    301 
    302   // Emits optimized code to deep-copy the contents of statically known
    303   // object graphs (e.g. object literal boilerplate).
    304   void EmitDeepCopy(Handle<JSObject> object,
    305                     Register result,
    306                     Register source,
    307                     int* offset,
    308                     AllocationSiteMode mode);
    309 
    310   void EnsureSpaceForLazyDeopt(int space_needed) V8_OVERRIDE;
    311   void DoLoadKeyedExternalArray(LLoadKeyed* instr);
    312   void DoLoadKeyedFixedDoubleArray(LLoadKeyed* instr);
    313   void DoLoadKeyedFixedArray(LLoadKeyed* instr);
    314   void DoStoreKeyedExternalArray(LStoreKeyed* instr);
    315   void DoStoreKeyedFixedDoubleArray(LStoreKeyed* instr);
    316   void DoStoreKeyedFixedArray(LStoreKeyed* instr);
    317 #ifdef _MSC_VER
    318   // On windows, you may not access the stack more than one page below
    319   // the most recently mapped page. To make the allocated area randomly
    320   // accessible, we write an arbitrary value to each page in range
    321   // rsp + offset - page_size .. rsp in turn.
    322   void MakeSureStackPagesMapped(int offset);
    323 #endif
    324 
    325   ZoneList<LEnvironment*> deoptimizations_;
    326   ZoneList<Deoptimizer::JumpTableEntry> jump_table_;
    327   ZoneList<Handle<Object> > deoptimization_literals_;
    328   int inlined_function_count_;
    329   Scope* const scope_;
    330   TranslationBuffer translations_;
    331   ZoneList<LDeferredCode*> deferred_;
    332   int osr_pc_offset_;
    333   bool frame_is_built_;
    334 
    335   // Builder that keeps track of safepoints in the code. The table
    336   // itself is emitted at the end of the generated code.
    337   SafepointTableBuilder safepoints_;
    338 
    339   // Compiler from a set of parallel moves to a sequential list of moves.
    340   LGapResolver resolver_;
    341 
    342   Safepoint::Kind expected_safepoint_kind_;
    343 
    344   class PushSafepointRegistersScope V8_FINAL BASE_EMBEDDED {
    345    public:
    346     explicit PushSafepointRegistersScope(LCodeGen* codegen)
    347         : codegen_(codegen) {
    348       ASSERT(codegen_->info()->is_calling());
    349       ASSERT(codegen_->expected_safepoint_kind_ == Safepoint::kSimple);
    350       codegen_->masm_->PushSafepointRegisters();
    351       codegen_->expected_safepoint_kind_ = Safepoint::kWithRegisters;
    352     }
    353 
    354     ~PushSafepointRegistersScope() {
    355       ASSERT(codegen_->expected_safepoint_kind_ == Safepoint::kWithRegisters);
    356       codegen_->masm_->PopSafepointRegisters();
    357       codegen_->expected_safepoint_kind_ = Safepoint::kSimple;
    358     }
    359 
    360    private:
    361     LCodeGen* codegen_;
    362   };
    363 
    364   friend class LDeferredCode;
    365   friend class LEnvironment;
    366   friend class SafepointGenerator;
    367   DISALLOW_COPY_AND_ASSIGN(LCodeGen);
    368 };
    369 
    370 
    371 class LDeferredCode: public ZoneObject {
    372  public:
    373   explicit LDeferredCode(LCodeGen* codegen)
    374       : codegen_(codegen),
    375         external_exit_(NULL),
    376         instruction_index_(codegen->current_instruction_) {
    377     codegen->AddDeferredCode(this);
    378   }
    379 
    380   virtual ~LDeferredCode() {}
    381   virtual void Generate() = 0;
    382   virtual LInstruction* instr() = 0;
    383 
    384   void SetExit(Label* exit) { external_exit_ = exit; }
    385   Label* entry() { return &entry_; }
    386   Label* exit() { return external_exit_ != NULL ? external_exit_ : &exit_; }
    387   Label* done() { return codegen_->NeedsDeferredFrame() ? &done_ : exit(); }
    388   int instruction_index() const { return instruction_index_; }
    389 
    390  protected:
    391   LCodeGen* codegen() const { return codegen_; }
    392   MacroAssembler* masm() const { return codegen_->masm(); }
    393 
    394  private:
    395   LCodeGen* codegen_;
    396   Label entry_;
    397   Label exit_;
    398   Label done_;
    399   Label* external_exit_;
    400   int instruction_index_;
    401 };
    402 
    403 } }  // namespace v8::internal
    404 
    405 #endif  // V8_X64_LITHIUM_CODEGEN_X64_H_
    406