// Copyright 2011 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. // Declares a Simulator for MIPS instructions if we are not generating a native // MIPS binary. This Simulator allows us to run and debug MIPS code generation // on regular desktop machines. // V8 calls into generated code via the GeneratedCode wrapper, // which will start execution in the Simulator or forwards to the real entry // on a MIPS HW platform. #ifndef V8_MIPS_SIMULATOR_MIPS_H_ #define V8_MIPS_SIMULATOR_MIPS_H_ #include "src/allocation.h" #include "src/mips/constants-mips.h" #if defined(USE_SIMULATOR) // Running with a simulator. #include "src/assembler.h" #include "src/base/hashmap.h" #include "src/simulator-base.h" namespace v8 { namespace internal { // ----------------------------------------------------------------------------- // Utility functions class CachePage { public: static const int LINE_VALID = 0; static const int LINE_INVALID = 1; static const int kPageShift = 12; static const int kPageSize = 1 << kPageShift; static const int kPageMask = kPageSize - 1; static const int kLineShift = 2; // The cache line is only 4 bytes right now. static const int kLineLength = 1 << kLineShift; static const int kLineMask = kLineLength - 1; CachePage() { memset(&validity_map_, LINE_INVALID, sizeof(validity_map_)); } char* ValidityByte(int offset) { return &validity_map_[offset >> kLineShift]; } char* CachedData(int offset) { return &data_[offset]; } private: char data_[kPageSize]; // The cached data. static const int kValidityMapSize = kPageSize >> kLineShift; char validity_map_[kValidityMapSize]; // One byte per line. }; class SimInstructionBase : public InstructionBase { public: Type InstructionType() const { return type_; } inline Instruction* instr() const { return instr_; } inline int32_t operand() const { return operand_; } protected: SimInstructionBase() : operand_(-1), instr_(nullptr), type_(kUnsupported) {} explicit SimInstructionBase(Instruction* instr) {} int32_t operand_; Instruction* instr_; Type type_; private: DISALLOW_ASSIGN(SimInstructionBase); }; class SimInstruction : public InstructionGetters<SimInstructionBase> { public: SimInstruction() {} explicit SimInstruction(Instruction* instr) { *this = instr; } SimInstruction& operator=(Instruction* instr) { operand_ = *reinterpret_cast<const int32_t*>(instr); instr_ = instr; type_ = InstructionBase::InstructionType(); DCHECK(reinterpret_cast<void*>(&operand_) == this); return *this; } }; class Simulator : public SimulatorBase { public: friend class MipsDebugger; // Registers are declared in order. See SMRL chapter 2. enum Register { no_reg = -1, zero_reg = 0, at, v0, v1, a0, a1, a2, a3, t0, t1, t2, t3, t4, t5, t6, t7, s0, s1, s2, s3, s4, s5, s6, s7, t8, t9, k0, k1, gp, sp, s8, ra, // LO, HI, and pc. LO, HI, pc, // pc must be the last register. kNumSimuRegisters, // aliases fp = s8 }; // Coprocessor registers. // Generated code will always use doubles. So we will only use even registers. enum FPURegister { f0, f1, f2, f3, f4, f5, f6, f7, f8, f9, f10, f11, f12, f13, f14, f15, // f12 and f14 are arguments FPURegisters. f16, f17, f18, f19, f20, f21, f22, f23, f24, f25, f26, f27, f28, f29, f30, f31, kNumFPURegisters }; // MSA registers enum MSARegister { w0, w1, w2, w3, w4, w5, w6, w7, w8, w9, w10, w11, w12, w13, w14, w15, w16, w17, w18, w19, w20, w21, w22, w23, w24, w25, w26, w27, w28, w29, w30, w31, kNumMSARegisters }; explicit Simulator(Isolate* isolate); ~Simulator(); // The currently executing Simulator instance. Potentially there can be one // for each native thread. V8_EXPORT_PRIVATE static Simulator* current(v8::internal::Isolate* isolate); // Accessors for register state. Reading the pc value adheres to the MIPS // architecture specification and is off by a 8 from the currently executing // instruction. void set_register(int reg, int32_t value); void set_dw_register(int dreg, const int* dbl); int32_t get_register(int reg) const; double get_double_from_register_pair(int reg); // Same for FPURegisters. void set_fpu_register(int fpureg, int64_t value); void set_fpu_register_word(int fpureg, int32_t value); void set_fpu_register_hi_word(int fpureg, int32_t value); void set_fpu_register_float(int fpureg, float value); void set_fpu_register_double(int fpureg, double value); void set_fpu_register_invalid_result64(float original, float rounded); void set_fpu_register_invalid_result(float original, float rounded); void set_fpu_register_word_invalid_result(float original, float rounded); void set_fpu_register_invalid_result64(double original, double rounded); void set_fpu_register_invalid_result(double original, double rounded); void set_fpu_register_word_invalid_result(double original, double rounded); int64_t get_fpu_register(int fpureg) const; int32_t get_fpu_register_word(int fpureg) const; int32_t get_fpu_register_signed_word(int fpureg) const; int32_t get_fpu_register_hi_word(int fpureg) const; float get_fpu_register_float(int fpureg) const; double get_fpu_register_double(int fpureg) const; template <typename T> void get_msa_register(int wreg, T* value); template <typename T> void set_msa_register(int wreg, const T* value); void set_fcsr_bit(uint32_t cc, bool value); bool test_fcsr_bit(uint32_t cc); void set_fcsr_rounding_mode(FPURoundingMode mode); void set_msacsr_rounding_mode(FPURoundingMode mode); unsigned int get_fcsr_rounding_mode(); unsigned int get_msacsr_rounding_mode(); bool set_fcsr_round_error(double original, double rounded); bool set_fcsr_round_error(float original, float rounded); bool set_fcsr_round64_error(double original, double rounded); bool set_fcsr_round64_error(float original, float rounded); void round_according_to_fcsr(double toRound, double& rounded, int32_t& rounded_int, double fs); void round_according_to_fcsr(float toRound, float& rounded, int32_t& rounded_int, float fs); template <typename Tfp, typename Tint> void round_according_to_msacsr(Tfp toRound, Tfp& rounded, Tint& rounded_int); void round64_according_to_fcsr(double toRound, double& rounded, int64_t& rounded_int, double fs); void round64_according_to_fcsr(float toRound, float& rounded, int64_t& rounded_int, float fs); // Special case of set_register and get_register to access the raw PC value. void set_pc(int32_t value); int32_t get_pc() const; Address get_sp() const { return static_cast<Address>(get_register(sp)); } // Accessor to the internal simulator stack area. uintptr_t StackLimit(uintptr_t c_limit) const; // Executes MIPS instructions until the PC reaches end_sim_pc. void Execute(); template <typename Return, typename... Args> Return Call(Address entry, Args... args) { return VariadicCall<Return>(this, &Simulator::CallImpl, entry, args...); } // Alternative: call a 2-argument double function. double CallFP(Address entry, double d0, double d1); // Push an address onto the JS stack. uintptr_t PushAddress(uintptr_t address); // Pop an address from the JS stack. uintptr_t PopAddress(); // Debugger input. void set_last_debugger_input(char* input); char* last_debugger_input() { return last_debugger_input_; } // Redirection support. static void SetRedirectInstruction(Instruction* instruction); // ICache checking. static bool ICacheMatch(void* one, void* two); static void FlushICache(base::CustomMatcherHashMap* i_cache, void* start, size_t size); // Returns true if pc register contains one of the 'special_values' defined // below (bad_ra, end_sim_pc). bool has_bad_pc() const; private: enum special_values { // Known bad pc value to ensure that the simulator does not execute // without being properly setup. bad_ra = -1, // A pc value used to signal the simulator to stop execution. Generally // the ra is set to this value on transition from native C code to // simulated execution, so that the simulator can "return" to the native // C code. end_sim_pc = -2, // Unpredictable value. Unpredictable = 0xbadbeaf }; V8_EXPORT_PRIVATE intptr_t CallImpl(Address entry, int argument_count, const intptr_t* arguments); // Unsupported instructions use Format to print an error and stop execution. void Format(Instruction* instr, const char* format); // Helpers for data value tracing. enum TraceType { BYTE, HALF, WORD, DWORD, FLOAT, DOUBLE, FLOAT_DOUBLE }; // MSA Data Format enum MSADataFormat { MSA_VECT = 0, MSA_BYTE, MSA_HALF, MSA_WORD, MSA_DWORD }; typedef union { int8_t b[kMSALanesByte]; uint8_t ub[kMSALanesByte]; int16_t h[kMSALanesHalf]; uint16_t uh[kMSALanesHalf]; int32_t w[kMSALanesWord]; uint32_t uw[kMSALanesWord]; int64_t d[kMSALanesDword]; uint64_t ud[kMSALanesDword]; } msa_reg_t; // Read and write memory. inline uint32_t ReadBU(int32_t addr); inline int32_t ReadB(int32_t addr); inline void WriteB(int32_t addr, uint8_t value); inline void WriteB(int32_t addr, int8_t value); inline uint16_t ReadHU(int32_t addr, Instruction* instr); inline int16_t ReadH(int32_t addr, Instruction* instr); // Note: Overloaded on the sign of the value. inline void WriteH(int32_t addr, uint16_t value, Instruction* instr); inline void WriteH(int32_t addr, int16_t value, Instruction* instr); inline int ReadW(int32_t addr, Instruction* instr, TraceType t = WORD); inline void WriteW(int32_t addr, int value, Instruction* instr); void WriteConditionalW(int32_t addr, int32_t value, Instruction* instr, int32_t rt_reg); inline double ReadD(int32_t addr, Instruction* instr); inline void WriteD(int32_t addr, double value, Instruction* instr); template <typename T> T ReadMem(int32_t addr, Instruction* instr); template <typename T> void WriteMem(int32_t addr, T value, Instruction* instr); void TraceRegWr(int32_t value, TraceType t = WORD); void TraceRegWr(int64_t value, TraceType t = DWORD); template <typename T> void TraceMSARegWr(T* value, TraceType t); template <typename T> void TraceMSARegWr(T* value); void TraceMemWr(int32_t addr, int32_t value, TraceType t = WORD); void TraceMemRd(int32_t addr, int32_t value, TraceType t = WORD); void TraceMemWr(int32_t addr, int64_t value, TraceType t = DWORD); void TraceMemRd(int32_t addr, int64_t value, TraceType t = DWORD); template <typename T> void TraceMemRd(int32_t addr, T value); template <typename T> void TraceMemWr(int32_t addr, T value); EmbeddedVector<char, 128> trace_buf_; // Operations depending on endianness. // Get Double Higher / Lower word. inline int32_t GetDoubleHIW(double* addr); inline int32_t GetDoubleLOW(double* addr); // Set Double Higher / Lower word. inline int32_t SetDoubleHIW(double* addr); inline int32_t SetDoubleLOW(double* addr); SimInstruction instr_; // Executing is handled based on the instruction type. void DecodeTypeRegister(); // Functions called from DecodeTypeRegister. void DecodeTypeRegisterCOP1(); void DecodeTypeRegisterCOP1X(); void DecodeTypeRegisterSPECIAL(); void DecodeTypeRegisterSPECIAL2(); void DecodeTypeRegisterSPECIAL3(); // Called from DecodeTypeRegisterCOP1. void DecodeTypeRegisterSRsType(); void DecodeTypeRegisterDRsType(); void DecodeTypeRegisterWRsType(); void DecodeTypeRegisterLRsType(); int DecodeMsaDataFormat(); void DecodeTypeMsaI8(); void DecodeTypeMsaI5(); void DecodeTypeMsaI10(); void DecodeTypeMsaELM(); void DecodeTypeMsaBIT(); void DecodeTypeMsaMI10(); void DecodeTypeMsa3R(); void DecodeTypeMsa3RF(); void DecodeTypeMsaVec(); void DecodeTypeMsa2R(); void DecodeTypeMsa2RF(); template <typename T> T MsaI5InstrHelper(uint32_t opcode, T ws, int32_t i5); template <typename T> T MsaBitInstrHelper(uint32_t opcode, T wd, T ws, int32_t m); template <typename T> T Msa3RInstrHelper(uint32_t opcode, T wd, T ws, T wt); inline int32_t rs_reg() const { return instr_.RsValue(); } inline int32_t rs() const { return get_register(rs_reg()); } inline uint32_t rs_u() const { return static_cast<uint32_t>(get_register(rs_reg())); } inline int32_t rt_reg() const { return instr_.RtValue(); } inline int32_t rt() const { return get_register(rt_reg()); } inline uint32_t rt_u() const { return static_cast<uint32_t>(get_register(rt_reg())); } inline int32_t rd_reg() const { return instr_.RdValue(); } inline int32_t fr_reg() const { return instr_.FrValue(); } inline int32_t fs_reg() const { return instr_.FsValue(); } inline int32_t ft_reg() const { return instr_.FtValue(); } inline int32_t fd_reg() const { return instr_.FdValue(); } inline int32_t sa() const { return instr_.SaValue(); } inline int32_t lsa_sa() const { return instr_.LsaSaValue(); } inline int32_t ws_reg() const { return instr_.WsValue(); } inline int32_t wt_reg() const { return instr_.WtValue(); } inline int32_t wd_reg() const { return instr_.WdValue(); } inline void SetResult(int32_t rd_reg, int32_t alu_out) { set_register(rd_reg, alu_out); TraceRegWr(alu_out); } inline void SetFPUWordResult(int32_t fd_reg, int32_t alu_out) { set_fpu_register_word(fd_reg, alu_out); TraceRegWr(get_fpu_register_word(fd_reg)); } inline void SetFPUResult(int32_t fd_reg, int64_t alu_out) { set_fpu_register(fd_reg, alu_out); TraceRegWr(get_fpu_register(fd_reg)); } inline void SetFPUFloatResult(int32_t fd_reg, float alu_out) { set_fpu_register_float(fd_reg, alu_out); TraceRegWr(get_fpu_register_word(fd_reg), FLOAT); } inline void SetFPUDoubleResult(int32_t fd_reg, double alu_out) { set_fpu_register_double(fd_reg, alu_out); TraceRegWr(get_fpu_register(fd_reg), DOUBLE); } void DecodeTypeImmediate(); void DecodeTypeJump(); // Used for breakpoints and traps. void SoftwareInterrupt(); // Compact branch guard. void CheckForbiddenSlot(int32_t current_pc) { Instruction* instr_after_compact_branch = reinterpret_cast<Instruction*>(current_pc + kInstrSize); if (instr_after_compact_branch->IsForbiddenAfterBranch()) { FATAL( "Error: Unexpected instruction 0x%08x immediately after a " "compact branch instruction.", *reinterpret_cast<uint32_t*>(instr_after_compact_branch)); } } // Stop helper functions. bool IsWatchpoint(uint32_t code); void PrintWatchpoint(uint32_t code); void HandleStop(uint32_t code, Instruction* instr); bool IsStopInstruction(Instruction* instr); bool IsEnabledStop(uint32_t code); void EnableStop(uint32_t code); void DisableStop(uint32_t code); void IncreaseStopCounter(uint32_t code); void PrintStopInfo(uint32_t code); // Executes one instruction. void InstructionDecode(Instruction* instr); // Execute one instruction placed in a branch delay slot. void BranchDelayInstructionDecode(Instruction* instr) { if (instr->InstructionBits() == nopInstr) { // Short-cut generic nop instructions. They are always valid and they // never change the simulator state. return; } if (instr->IsForbiddenInBranchDelay()) { FATAL("Eror:Unexpected %i opcode in a branch delay slot.", instr->OpcodeValue()); } InstructionDecode(instr); SNPrintF(trace_buf_, " "); } // ICache. static void CheckICache(base::CustomMatcherHashMap* i_cache, Instruction* instr); static void FlushOnePage(base::CustomMatcherHashMap* i_cache, intptr_t start, int size); static CachePage* GetCachePage(base::CustomMatcherHashMap* i_cache, void* page); enum Exception { none, kIntegerOverflow, kIntegerUnderflow, kDivideByZero, kNumExceptions }; // Exceptions. void SignalException(Exception e); // Handle arguments and return value for runtime FP functions. void GetFpArgs(double* x, double* y, int32_t* z); void SetFpResult(const double& result); void CallInternal(Address entry); // Architecture state. // Registers. int32_t registers_[kNumSimuRegisters]; // Coprocessor Registers. // Note: FP32 mode uses only the lower 32-bit part of each element, // the upper 32-bit is unpredictable. // Note: FPUregisters_[] array is increased to 64 * 8B = 32 * 16B in // order to support MSA registers int64_t FPUregisters_[kNumFPURegisters * 2]; // FPU control register. uint32_t FCSR_; // MSA control register. uint32_t MSACSR_; // Simulator support. // Allocate 1MB for stack. static const size_t stack_size_ = 1 * 1024*1024; char* stack_; bool pc_modified_; uint64_t icount_; int break_count_; // Debugger input. char* last_debugger_input_; v8::internal::Isolate* isolate_; // Registered breakpoints. Instruction* break_pc_; Instr break_instr_; // Stop is disabled if bit 31 is set. static const uint32_t kStopDisabledBit = 1 << 31; // A stop is enabled, meaning the simulator will stop when meeting the // instruction, if bit 31 of watched_stops_[code].count is unset. // The value watched_stops_[code].count & ~(1 << 31) indicates how many times // the breakpoint was hit or gone through. struct StopCountAndDesc { uint32_t count; char* desc; }; StopCountAndDesc watched_stops_[kMaxStopCode + 1]; // Synchronization primitives. enum class MonitorAccess { Open, RMW, }; enum class TransactionSize { None = 0, Word = 4, }; // The least-significant bits of the address are ignored. The number of bits // is implementation-defined, between 3 and minimum page size. static const uintptr_t kExclusiveTaggedAddrMask = ~((1 << 3) - 1); class LocalMonitor { public: LocalMonitor(); // These functions manage the state machine for the local monitor, but do // not actually perform loads and stores. NotifyStoreConditional only // returns true if the store conditional is allowed; the global monitor will // still have to be checked to see whether the memory should be updated. void NotifyLoad(); void NotifyLoadLinked(uintptr_t addr, TransactionSize size); void NotifyStore(); bool NotifyStoreConditional(uintptr_t addr, TransactionSize size); private: void Clear(); MonitorAccess access_state_; uintptr_t tagged_addr_; TransactionSize size_; }; class GlobalMonitor { public: GlobalMonitor(); class LinkedAddress { public: LinkedAddress(); private: friend class GlobalMonitor; // These functions manage the state machine for the global monitor, but do // not actually perform loads and stores. void Clear_Locked(); void NotifyLoadLinked_Locked(uintptr_t addr); void NotifyStore_Locked(); bool NotifyStoreConditional_Locked(uintptr_t addr, bool is_requesting_thread); MonitorAccess access_state_; uintptr_t tagged_addr_; LinkedAddress* next_; LinkedAddress* prev_; // A scd can fail due to background cache evictions. Rather than // simulating this, we'll just occasionally introduce cases where an // store conditional fails. This will happen once after every // kMaxFailureCounter exclusive stores. static const int kMaxFailureCounter = 5; int failure_counter_; }; // Exposed so it can be accessed by Simulator::{Read,Write}Ex*. base::Mutex mutex; void NotifyLoadLinked_Locked(uintptr_t addr, LinkedAddress* linked_address); void NotifyStore_Locked(LinkedAddress* linked_address); bool NotifyStoreConditional_Locked(uintptr_t addr, LinkedAddress* linked_address); // Called when the simulator is destroyed. void RemoveLinkedAddress(LinkedAddress* linked_address); private: bool IsProcessorInLinkedList_Locked(LinkedAddress* linked_address) const; void PrependProcessor_Locked(LinkedAddress* linked_address); LinkedAddress* head_; }; LocalMonitor local_monitor_; GlobalMonitor::LinkedAddress global_monitor_thread_; static base::LazyInstance<GlobalMonitor>::type global_monitor_; }; } // namespace internal } // namespace v8 #endif // defined(USE_SIMULATOR) #endif // V8_MIPS_SIMULATOR_MIPS_H_