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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_X87_LITHIUM_CODEGEN_X87_H_
      6 #define V8_X87_LITHIUM_CODEGEN_X87_H_
      7 
      8 #include "src/x87/lithium-x87.h"
      9 
     10 #include "src/checks.h"
     11 #include "src/deoptimizer.h"
     12 #include "src/x87/lithium-gap-resolver-x87.h"
     13 #include "src/lithium-codegen.h"
     14 #include "src/safepoint-table.h"
     15 #include "src/scopes.h"
     16 #include "src/utils.h"
     17 
     18 namespace v8 {
     19 namespace internal {
     20 
     21 // Forward declarations.
     22 class LDeferredCode;
     23 class LGapNode;
     24 class SafepointGenerator;
     25 
     26 class LCodeGen: public LCodeGenBase {
     27  public:
     28   LCodeGen(LChunk* chunk, MacroAssembler* assembler, CompilationInfo* info)
     29       : LCodeGenBase(chunk, assembler, info),
     30         deoptimizations_(4, info->zone()),
     31         jump_table_(4, info->zone()),
     32         deoptimization_literals_(8, info->zone()),
     33         inlined_function_count_(0),
     34         scope_(info->scope()),
     35         translations_(info->zone()),
     36         deferred_(8, info->zone()),
     37         dynamic_frame_alignment_(false),
     38         support_aligned_spilled_doubles_(false),
     39         osr_pc_offset_(-1),
     40         frame_is_built_(false),
     41         x87_stack_(assembler),
     42         safepoints_(info->zone()),
     43         resolver_(this),
     44         expected_safepoint_kind_(Safepoint::kSimple) {
     45     PopulateDeoptimizationLiteralsWithInlinedFunctions();
     46   }
     47 
     48   int LookupDestination(int block_id) const {
     49     return chunk()->LookupDestination(block_id);
     50   }
     51 
     52   bool IsNextEmittedBlock(int block_id) const {
     53     return LookupDestination(block_id) == GetNextEmittedBlock();
     54   }
     55 
     56   bool NeedsEagerFrame() const {
     57     return GetStackSlotCount() > 0 ||
     58         info()->is_non_deferred_calling() ||
     59         !info()->IsStub() ||
     60         info()->requires_frame();
     61   }
     62   bool NeedsDeferredFrame() const {
     63     return !NeedsEagerFrame() && info()->is_deferred_calling();
     64   }
     65 
     66   // Support for converting LOperands to assembler types.
     67   Operand ToOperand(LOperand* op) const;
     68   Register ToRegister(LOperand* op) const;
     69   X87Register ToX87Register(LOperand* op) const;
     70 
     71   bool IsInteger32(LConstantOperand* op) const;
     72   bool IsSmi(LConstantOperand* op) const;
     73   Immediate ToImmediate(LOperand* op, const Representation& r) const {
     74     return Immediate(ToRepresentation(LConstantOperand::cast(op), r));
     75   }
     76   double ToDouble(LConstantOperand* op) const;
     77 
     78   // Support for non-sse2 (x87) floating point stack handling.
     79   // These functions maintain the mapping of physical stack registers to our
     80   // virtual registers between instructions.
     81   enum X87OperandType { kX87DoubleOperand, kX87FloatOperand, kX87IntOperand };
     82 
     83   void X87Mov(X87Register reg, Operand src,
     84       X87OperandType operand = kX87DoubleOperand);
     85   void X87Mov(Operand src, X87Register reg,
     86       X87OperandType operand = kX87DoubleOperand);
     87 
     88   void X87PrepareBinaryOp(
     89       X87Register left, X87Register right, X87Register result);
     90 
     91   void X87LoadForUsage(X87Register reg);
     92   void X87LoadForUsage(X87Register reg1, X87Register reg2);
     93   void X87PrepareToWrite(X87Register reg) { x87_stack_.PrepareToWrite(reg); }
     94   void X87CommitWrite(X87Register reg) { x87_stack_.CommitWrite(reg); }
     95 
     96   void X87Fxch(X87Register reg, int other_slot = 0) {
     97     x87_stack_.Fxch(reg, other_slot);
     98   }
     99   void X87Free(X87Register reg) {
    100     x87_stack_.Free(reg);
    101   }
    102 
    103 
    104   bool X87StackEmpty() {
    105     return x87_stack_.depth() == 0;
    106   }
    107 
    108   Handle<Object> ToHandle(LConstantOperand* op) const;
    109 
    110   // The operand denoting the second word (the one with a higher address) of
    111   // a double stack slot.
    112   Operand HighOperand(LOperand* op);
    113 
    114   // Try to generate code for the entire chunk, but it may fail if the
    115   // chunk contains constructs we cannot handle. Returns true if the
    116   // code generation attempt succeeded.
    117   bool GenerateCode();
    118 
    119   // Finish the code by setting stack height, safepoint, and bailout
    120   // information on it.
    121   void FinishCode(Handle<Code> code);
    122 
    123   // Deferred code support.
    124   void DoDeferredNumberTagD(LNumberTagD* instr);
    125 
    126   enum IntegerSignedness { SIGNED_INT32, UNSIGNED_INT32 };
    127   void DoDeferredNumberTagIU(LInstruction* instr,
    128                              LOperand* value,
    129                              LOperand* temp,
    130                              IntegerSignedness signedness);
    131 
    132   void DoDeferredTaggedToI(LTaggedToI* instr, Label* done);
    133   void DoDeferredMathAbsTaggedHeapNumber(LMathAbs* instr);
    134   void DoDeferredStackCheck(LStackCheck* instr);
    135   void DoDeferredStringCharCodeAt(LStringCharCodeAt* instr);
    136   void DoDeferredStringCharFromCode(LStringCharFromCode* instr);
    137   void DoDeferredAllocate(LAllocate* instr);
    138   void DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
    139                                        Label* map_check);
    140   void DoDeferredInstanceMigration(LCheckMaps* instr, Register object);
    141   void DoDeferredLoadMutableDouble(LLoadFieldByIndex* instr,
    142                                    Register object,
    143                                    Register index);
    144 
    145   // Parallel move support.
    146   void DoParallelMove(LParallelMove* move);
    147   void DoGap(LGap* instr);
    148 
    149   // Emit frame translation commands for an environment.
    150   void WriteTranslation(LEnvironment* environment, Translation* translation);
    151 
    152   void EnsureRelocSpaceForDeoptimization();
    153 
    154   // Declare methods that deal with the individual node types.
    155 #define DECLARE_DO(type) void Do##type(L##type* node);
    156   LITHIUM_CONCRETE_INSTRUCTION_LIST(DECLARE_DO)
    157 #undef DECLARE_DO
    158 
    159  private:
    160   StrictMode strict_mode() const { return info()->strict_mode(); }
    161 
    162   Scope* scope() const { return scope_; }
    163 
    164   void EmitClassOfTest(Label* if_true,
    165                        Label* if_false,
    166                        Handle<String> class_name,
    167                        Register input,
    168                        Register temporary,
    169                        Register temporary2);
    170 
    171   int GetStackSlotCount() const { return chunk()->spill_slot_count(); }
    172 
    173   void AddDeferredCode(LDeferredCode* code) { deferred_.Add(code, zone()); }
    174 
    175   // Code generation passes.  Returns true if code generation should
    176   // continue.
    177   void GenerateBodyInstructionPre(LInstruction* instr) V8_OVERRIDE;
    178   void GenerateBodyInstructionPost(LInstruction* instr) V8_OVERRIDE;
    179   bool GeneratePrologue();
    180   bool GenerateDeferredCode();
    181   bool GenerateJumpTable();
    182   bool GenerateSafepointTable();
    183 
    184   // Generates the custom OSR entrypoint and sets the osr_pc_offset.
    185   void GenerateOsrPrologue();
    186 
    187   enum SafepointMode {
    188     RECORD_SIMPLE_SAFEPOINT,
    189     RECORD_SAFEPOINT_WITH_REGISTERS_AND_NO_ARGUMENTS
    190   };
    191 
    192   void CallCode(Handle<Code> code,
    193                 RelocInfo::Mode mode,
    194                 LInstruction* instr);
    195 
    196   void CallCodeGeneric(Handle<Code> code,
    197                        RelocInfo::Mode mode,
    198                        LInstruction* instr,
    199                        SafepointMode safepoint_mode);
    200 
    201   void CallRuntime(const Runtime::Function* fun,
    202                    int argc,
    203                    LInstruction* instr);
    204 
    205   void CallRuntime(Runtime::FunctionId id,
    206                    int argc,
    207                    LInstruction* instr) {
    208     const Runtime::Function* function = Runtime::FunctionForId(id);
    209     CallRuntime(function, argc, instr);
    210   }
    211 
    212   void CallRuntimeFromDeferred(Runtime::FunctionId id,
    213                                int argc,
    214                                LInstruction* instr,
    215                                LOperand* context);
    216 
    217   void LoadContextFromDeferred(LOperand* context);
    218 
    219   enum EDIState {
    220     EDI_UNINITIALIZED,
    221     EDI_CONTAINS_TARGET
    222   };
    223 
    224   // Generate a direct call to a known function.  Expects the function
    225   // to be in edi.
    226   void CallKnownFunction(Handle<JSFunction> function,
    227                          int formal_parameter_count,
    228                          int arity,
    229                          LInstruction* instr,
    230                          EDIState edi_state);
    231 
    232   void RecordSafepointWithLazyDeopt(LInstruction* instr,
    233                                     SafepointMode safepoint_mode);
    234 
    235   void RegisterEnvironmentForDeoptimization(LEnvironment* environment,
    236                                             Safepoint::DeoptMode mode);
    237   void DeoptimizeIf(Condition cc,
    238                     LEnvironment* environment,
    239                     Deoptimizer::BailoutType bailout_type);
    240   void DeoptimizeIf(Condition cc, LEnvironment* environment);
    241 
    242   bool DeoptEveryNTimes() {
    243     return FLAG_deopt_every_n_times != 0 && !info()->IsStub();
    244   }
    245 
    246   void AddToTranslation(LEnvironment* environment,
    247                         Translation* translation,
    248                         LOperand* op,
    249                         bool is_tagged,
    250                         bool is_uint32,
    251                         int* object_index_pointer,
    252                         int* dematerialized_index_pointer);
    253   void PopulateDeoptimizationData(Handle<Code> code);
    254   int DefineDeoptimizationLiteral(Handle<Object> literal);
    255 
    256   void PopulateDeoptimizationLiteralsWithInlinedFunctions();
    257 
    258   Register ToRegister(int index) const;
    259   X87Register ToX87Register(int index) const;
    260   int32_t ToRepresentation(LConstantOperand* op, const Representation& r) const;
    261   int32_t ToInteger32(LConstantOperand* op) const;
    262   ExternalReference ToExternalReference(LConstantOperand* op) const;
    263 
    264   Operand BuildFastArrayOperand(LOperand* elements_pointer,
    265                                 LOperand* key,
    266                                 Representation key_representation,
    267                                 ElementsKind elements_kind,
    268                                 uint32_t base_offset);
    269 
    270   Operand BuildSeqStringOperand(Register string,
    271                                 LOperand* index,
    272                                 String::Encoding encoding);
    273 
    274   void EmitIntegerMathAbs(LMathAbs* instr);
    275 
    276   // Support for recording safepoint and position information.
    277   void RecordSafepoint(LPointerMap* pointers,
    278                        Safepoint::Kind kind,
    279                        int arguments,
    280                        Safepoint::DeoptMode mode);
    281   void RecordSafepoint(LPointerMap* pointers, Safepoint::DeoptMode mode);
    282   void RecordSafepoint(Safepoint::DeoptMode mode);
    283   void RecordSafepointWithRegisters(LPointerMap* pointers,
    284                                     int arguments,
    285                                     Safepoint::DeoptMode mode);
    286 
    287   void RecordAndWritePosition(int position) V8_OVERRIDE;
    288 
    289   static Condition TokenToCondition(Token::Value op, bool is_unsigned);
    290   void EmitGoto(int block);
    291 
    292   // EmitBranch expects to be the last instruction of a block.
    293   template<class InstrType>
    294   void EmitBranch(InstrType instr, Condition cc);
    295   template<class InstrType>
    296   void EmitFalseBranch(InstrType instr, Condition cc);
    297   void EmitNumberUntagDNoSSE2(
    298       Register input,
    299       Register temp,
    300       X87Register res_reg,
    301       bool allow_undefined_as_nan,
    302       bool deoptimize_on_minus_zero,
    303       LEnvironment* env,
    304       NumberUntagDMode mode = NUMBER_CANDIDATE_IS_ANY_TAGGED);
    305 
    306   // Emits optimized code for typeof x == "y".  Modifies input register.
    307   // Returns the condition on which a final split to
    308   // true and false label should be made, to optimize fallthrough.
    309   Condition EmitTypeofIs(LTypeofIsAndBranch* instr, Register input);
    310 
    311   // Emits optimized code for %_IsObject(x).  Preserves input register.
    312   // Returns the condition on which a final split to
    313   // true and false label should be made, to optimize fallthrough.
    314   Condition EmitIsObject(Register input,
    315                          Register temp1,
    316                          Label* is_not_object,
    317                          Label* is_object);
    318 
    319   // Emits optimized code for %_IsString(x).  Preserves input register.
    320   // Returns the condition on which a final split to
    321   // true and false label should be made, to optimize fallthrough.
    322   Condition EmitIsString(Register input,
    323                          Register temp1,
    324                          Label* is_not_string,
    325                          SmiCheck check_needed);
    326 
    327   // Emits optimized code for %_IsConstructCall().
    328   // Caller should branch on equal condition.
    329   void EmitIsConstructCall(Register temp);
    330 
    331   // Emits optimized code to deep-copy the contents of statically known
    332   // object graphs (e.g. object literal boilerplate).
    333   void EmitDeepCopy(Handle<JSObject> object,
    334                     Register result,
    335                     Register source,
    336                     int* offset,
    337                     AllocationSiteMode mode);
    338 
    339   void EnsureSpaceForLazyDeopt(int space_needed) V8_OVERRIDE;
    340   void DoLoadKeyedExternalArray(LLoadKeyed* instr);
    341   void DoLoadKeyedFixedDoubleArray(LLoadKeyed* instr);
    342   void DoLoadKeyedFixedArray(LLoadKeyed* instr);
    343   void DoStoreKeyedExternalArray(LStoreKeyed* instr);
    344   void DoStoreKeyedFixedDoubleArray(LStoreKeyed* instr);
    345   void DoStoreKeyedFixedArray(LStoreKeyed* instr);
    346 
    347   void EmitReturn(LReturn* instr, bool dynamic_frame_alignment);
    348 
    349   // Emits code for pushing either a tagged constant, a (non-double)
    350   // register, or a stack slot operand.
    351   void EmitPushTaggedOperand(LOperand* operand);
    352 
    353   void X87Fld(Operand src, X87OperandType opts);
    354 
    355   void EmitFlushX87ForDeopt();
    356   void FlushX87StackIfNecessary(LInstruction* instr) {
    357     x87_stack_.FlushIfNecessary(instr, this);
    358   }
    359   friend class LGapResolver;
    360 
    361 #ifdef _MSC_VER
    362   // On windows, you may not access the stack more than one page below
    363   // the most recently mapped page. To make the allocated area randomly
    364   // accessible, we write an arbitrary value to each page in range
    365   // esp + offset - page_size .. esp in turn.
    366   void MakeSureStackPagesMapped(int offset);
    367 #endif
    368 
    369   ZoneList<LEnvironment*> deoptimizations_;
    370   ZoneList<Deoptimizer::JumpTableEntry> jump_table_;
    371   ZoneList<Handle<Object> > deoptimization_literals_;
    372   int inlined_function_count_;
    373   Scope* const scope_;
    374   TranslationBuffer translations_;
    375   ZoneList<LDeferredCode*> deferred_;
    376   bool dynamic_frame_alignment_;
    377   bool support_aligned_spilled_doubles_;
    378   int osr_pc_offset_;
    379   bool frame_is_built_;
    380 
    381   class X87Stack {
    382    public:
    383     explicit X87Stack(MacroAssembler* masm)
    384         : stack_depth_(0), is_mutable_(true), masm_(masm) { }
    385     explicit X87Stack(const X87Stack& other)
    386         : stack_depth_(other.stack_depth_), is_mutable_(false), masm_(masm()) {
    387       for (int i = 0; i < stack_depth_; i++) {
    388         stack_[i] = other.stack_[i];
    389       }
    390     }
    391     bool operator==(const X87Stack& other) const {
    392       if (stack_depth_ != other.stack_depth_) return false;
    393       for (int i = 0; i < stack_depth_; i++) {
    394         if (!stack_[i].is(other.stack_[i])) return false;
    395       }
    396       return true;
    397     }
    398     bool Contains(X87Register reg);
    399     void Fxch(X87Register reg, int other_slot = 0);
    400     void Free(X87Register reg);
    401     void PrepareToWrite(X87Register reg);
    402     void CommitWrite(X87Register reg);
    403     void FlushIfNecessary(LInstruction* instr, LCodeGen* cgen);
    404     void LeavingBlock(int current_block_id, LGoto* goto_instr);
    405     int depth() const { return stack_depth_; }
    406     void pop() {
    407       ASSERT(is_mutable_);
    408       stack_depth_--;
    409     }
    410     void push(X87Register reg) {
    411       ASSERT(is_mutable_);
    412       ASSERT(stack_depth_ < X87Register::kMaxNumAllocatableRegisters);
    413       stack_[stack_depth_] = reg;
    414       stack_depth_++;
    415     }
    416 
    417     MacroAssembler* masm() const { return masm_; }
    418     Isolate* isolate() const { return masm_->isolate(); }
    419 
    420    private:
    421     int ArrayIndex(X87Register reg);
    422     int st2idx(int pos);
    423 
    424     X87Register stack_[X87Register::kMaxNumAllocatableRegisters];
    425     int stack_depth_;
    426     bool is_mutable_;
    427     MacroAssembler* masm_;
    428   };
    429   X87Stack x87_stack_;
    430 
    431   // Builder that keeps track of safepoints in the code. The table
    432   // itself is emitted at the end of the generated code.
    433   SafepointTableBuilder safepoints_;
    434 
    435   // Compiler from a set of parallel moves to a sequential list of moves.
    436   LGapResolver resolver_;
    437 
    438   Safepoint::Kind expected_safepoint_kind_;
    439 
    440   class PushSafepointRegistersScope V8_FINAL  BASE_EMBEDDED {
    441    public:
    442     explicit PushSafepointRegistersScope(LCodeGen* codegen)
    443         : codegen_(codegen) {
    444       ASSERT(codegen_->expected_safepoint_kind_ == Safepoint::kSimple);
    445       codegen_->masm_->PushSafepointRegisters();
    446       codegen_->expected_safepoint_kind_ = Safepoint::kWithRegisters;
    447       ASSERT(codegen_->info()->is_calling());
    448     }
    449 
    450     ~PushSafepointRegistersScope() {
    451       ASSERT(codegen_->expected_safepoint_kind_ == Safepoint::kWithRegisters);
    452       codegen_->masm_->PopSafepointRegisters();
    453       codegen_->expected_safepoint_kind_ = Safepoint::kSimple;
    454     }
    455 
    456    private:
    457     LCodeGen* codegen_;
    458   };
    459 
    460   friend class LDeferredCode;
    461   friend class LEnvironment;
    462   friend class SafepointGenerator;
    463   DISALLOW_COPY_AND_ASSIGN(LCodeGen);
    464 };
    465 
    466 
    467 class LDeferredCode : public ZoneObject {
    468  public:
    469   explicit LDeferredCode(LCodeGen* codegen, const LCodeGen::X87Stack& x87_stack)
    470       : codegen_(codegen),
    471         external_exit_(NULL),
    472         instruction_index_(codegen->current_instruction_),
    473         x87_stack_(x87_stack) {
    474     codegen->AddDeferredCode(this);
    475   }
    476 
    477   virtual ~LDeferredCode() {}
    478   virtual void Generate() = 0;
    479   virtual LInstruction* instr() = 0;
    480 
    481   void SetExit(Label* exit) { external_exit_ = exit; }
    482   Label* entry() { return &entry_; }
    483   Label* exit() { return external_exit_ != NULL ? external_exit_ : &exit_; }
    484   Label* done() { return codegen_->NeedsDeferredFrame() ? &done_ : exit(); }
    485   int instruction_index() const { return instruction_index_; }
    486   const LCodeGen::X87Stack& x87_stack() const { return x87_stack_; }
    487 
    488  protected:
    489   LCodeGen* codegen() const { return codegen_; }
    490   MacroAssembler* masm() const { return codegen_->masm(); }
    491 
    492  private:
    493   LCodeGen* codegen_;
    494   Label entry_;
    495   Label exit_;
    496   Label* external_exit_;
    497   Label done_;
    498   int instruction_index_;
    499   LCodeGen::X87Stack x87_stack_;
    500 };
    501 
    502 } }  // namespace v8::internal
    503 
    504 #endif  // V8_X87_LITHIUM_CODEGEN_X87_H_
    505