diff options
Diffstat (limited to 'js/src/jit/mips32/Simulator-mips32.h')
| -rw-r--r-- | js/src/jit/mips32/Simulator-mips32.h | 526 |
1 files changed, 526 insertions, 0 deletions
diff --git a/js/src/jit/mips32/Simulator-mips32.h b/js/src/jit/mips32/Simulator-mips32.h new file mode 100644 index 0000000000..7ab204af54 --- /dev/null +++ b/js/src/jit/mips32/Simulator-mips32.h @@ -0,0 +1,526 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +// Copyright 2011 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 +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +#ifndef jit_mips32_Simulator_mips32_h +#define jit_mips32_Simulator_mips32_h + +#ifdef JS_SIMULATOR_MIPS32 + +# include "mozilla/Atomics.h" + +# include "jit/IonTypes.h" +# include "js/ProfilingFrameIterator.h" +# include "threading/Thread.h" +# include "vm/MutexIDs.h" +# include "wasm/WasmSignalHandlers.h" + +namespace js { + +namespace jit { + +class JitActivation; + +class Simulator; +class Redirection; +class CachePage; +class AutoLockSimulator; + +// When the SingleStepCallback is called, the simulator is about to execute +// sim->get_pc() and the current machine state represents the completed +// execution of the previous pc. +typedef void (*SingleStepCallback)(void* arg, Simulator* sim, void* pc); + +const intptr_t kPointerAlignment = 4; +const intptr_t kPointerAlignmentMask = kPointerAlignment - 1; + +const intptr_t kDoubleAlignment = 8; +const intptr_t kDoubleAlignmentMask = kDoubleAlignment - 1; + +// Number of general purpose registers. +const int kNumRegisters = 32; + +// In the simulator, the PC register is simulated as the 34th register. +const int kPCRegister = 34; + +// Number coprocessor registers. +const int kNumFPURegisters = 32; + +// FPU (coprocessor 1) control registers. Currently only FCSR is implemented. +const int kFCSRRegister = 31; +const int kInvalidFPUControlRegister = -1; +const uint32_t kFPUInvalidResult = static_cast<uint32_t>(1 << 31) - 1; + +// FCSR constants. +const uint32_t kFCSRInexactFlagBit = 2; +const uint32_t kFCSRUnderflowFlagBit = 3; +const uint32_t kFCSROverflowFlagBit = 4; +const uint32_t kFCSRDivideByZeroFlagBit = 5; +const uint32_t kFCSRInvalidOpFlagBit = 6; + +const uint32_t kFCSRInexactCauseBit = 12; +const uint32_t kFCSRUnderflowCauseBit = 13; +const uint32_t kFCSROverflowCauseBit = 14; +const uint32_t kFCSRDivideByZeroCauseBit = 15; +const uint32_t kFCSRInvalidOpCauseBit = 16; + +const uint32_t kFCSRInexactFlagMask = 1 << kFCSRInexactFlagBit; +const uint32_t kFCSRUnderflowFlagMask = 1 << kFCSRUnderflowFlagBit; +const uint32_t kFCSROverflowFlagMask = 1 << kFCSROverflowFlagBit; +const uint32_t kFCSRDivideByZeroFlagMask = 1 << kFCSRDivideByZeroFlagBit; +const uint32_t kFCSRInvalidOpFlagMask = 1 << kFCSRInvalidOpFlagBit; + +const uint32_t kFCSRFlagMask = + kFCSRInexactFlagMask | kFCSRUnderflowFlagMask | kFCSROverflowFlagMask | + kFCSRDivideByZeroFlagMask | kFCSRInvalidOpFlagMask; + +const uint32_t kFCSRExceptionFlagMask = kFCSRFlagMask ^ kFCSRInexactFlagMask; + +// On MIPS Simulator breakpoints can have different codes: +// - Breaks between 0 and kMaxWatchpointCode are treated as simple watchpoints, +// the simulator will run through them and print the registers. +// - Breaks between kMaxWatchpointCode and kMaxStopCode are treated as stop() +// instructions (see Assembler::stop()). +// - Breaks larger than kMaxStopCode are simple breaks, dropping you into the +// debugger. +const uint32_t kMaxWatchpointCode = 31; +const uint32_t kMaxStopCode = 127; +const uint32_t kWasmTrapCode = 6; + +// ----------------------------------------------------------------------------- +// Utility functions + +typedef uint32_t Instr; +class SimInstruction; + +// Per thread simulator state. +class Simulator { + friend class MipsDebugger; + + public: + // Registers are declared in order. See "See MIPS Run Linux" 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. + 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 + }; + + // Returns nullptr on OOM. + static Simulator* Create(); + + static void Destroy(Simulator* simulator); + + // Constructor/destructor are for internal use only; use the static methods + // above. + Simulator(); + ~Simulator(); + + // The currently executing Simulator instance. Potentially there can be one + // for each native thread. + static Simulator* Current(); + + static inline uintptr_t StackLimit() { + return Simulator::Current()->stackLimit(); + } + + uintptr_t* addressOfStackLimit(); + + // 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 setRegister(int reg, int32_t value); + int32_t getRegister(int reg) const; + double getDoubleFromRegisterPair(int reg); + // Same for FPURegisters. + void setFpuRegister(int fpureg, int32_t value); + void setFpuRegisterFloat(int fpureg, float value); + void setFpuRegisterFloat(int fpureg, int64_t value); + void setFpuRegisterDouble(int fpureg, double value); + void setFpuRegisterDouble(int fpureg, int64_t value); + int32_t getFpuRegister(int fpureg) const; + int64_t getFpuRegisterLong(int fpureg) const; + float getFpuRegisterFloat(int fpureg) const; + double getFpuRegisterDouble(int fpureg) const; + void setFCSRBit(uint32_t cc, bool value); + bool testFCSRBit(uint32_t cc); + bool setFCSRRoundError(double original, double rounded); + + // 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; + + template <typename T> + T get_pc_as() const { + return reinterpret_cast<T>(get_pc()); + } + + void enable_single_stepping(SingleStepCallback cb, void* arg); + void disable_single_stepping(); + + // Accessor to the internal simulator stack area. + uintptr_t stackLimit() const; + bool overRecursed(uintptr_t newsp = 0) const; + bool overRecursedWithExtra(uint32_t extra) const; + + // Executes MIPS instructions until the PC reaches end_sim_pc. + template <bool enableStopSimAt> + void execute(); + + // Sets up the simulator state and grabs the result on return. + int32_t call(uint8_t* entry, int argument_count, ...); + + // 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 setLastDebuggerInput(char* input); + char* lastDebuggerInput() { return lastDebuggerInput_; } + + // Returns true if pc register contains one of the 'SpecialValues' defined + // below (bad_ra, end_sim_pc). + bool has_bad_pc() const; + + private: + enum SpecialValues { + // 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 + }; + + bool init(); + + // Unsupported instructions use Format to print an error and stop execution. + void format(SimInstruction* instr, const char* format); + + // Read and write memory. + inline uint32_t readBU(uint32_t addr); + inline int32_t readB(uint32_t addr); + inline void writeB(uint32_t addr, uint8_t value); + inline void writeB(uint32_t addr, int8_t value); + + inline uint16_t readHU(uint32_t addr, SimInstruction* instr); + inline int16_t readH(uint32_t addr, SimInstruction* instr); + // Note: Overloaded on the sign of the value. + inline void writeH(uint32_t addr, uint16_t value, SimInstruction* instr); + inline void writeH(uint32_t addr, int16_t value, SimInstruction* instr); + + inline int readW(uint32_t addr, SimInstruction* instr); + inline void writeW(uint32_t addr, int value, SimInstruction* instr); + + inline double readD(uint32_t addr, SimInstruction* instr); + inline void writeD(uint32_t addr, double value, SimInstruction* instr); + + inline int32_t loadLinkedW(uint32_t addr, SimInstruction* instr); + inline int32_t storeConditionalW(uint32_t addr, int32_t value, + SimInstruction* instr); + + // Executing is handled based on the instruction type. + void decodeTypeRegister(SimInstruction* instr); + + // Helper function for decodeTypeRegister. + void configureTypeRegister(SimInstruction* instr, int32_t& alu_out, + int64_t& i64hilo, uint64_t& u64hilo, + int32_t& next_pc, int32_t& return_addr_reg, + bool& do_interrupt); + + void decodeTypeImmediate(SimInstruction* instr); + void decodeTypeJump(SimInstruction* instr); + + // Used for breakpoints and traps. + void softwareInterrupt(SimInstruction* instr); + + // Stop helper functions. + bool isWatchpoint(uint32_t code); + void printWatchpoint(uint32_t code); + void handleStop(uint32_t code, SimInstruction* instr); + bool isStopInstruction(SimInstruction* 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); + + JS::ProfilingFrameIterator::RegisterState registerState(); + + // Handle any wasm faults, returning true if the fault was handled. + // This method is rather hot so inline the normal (no-wasm) case. + bool MOZ_ALWAYS_INLINE handleWasmSegFault(int32_t addr, unsigned numBytes) { + if (MOZ_LIKELY(!js::wasm::CodeExists)) { + return false; + } + + uint8_t* newPC; + if (!js::wasm::MemoryAccessTraps(registerState(), (uint8_t*)addr, numBytes, + &newPC)) { + return false; + } + + LLBit_ = false; + set_pc(int32_t(newPC)); + return true; + } + + // Executes one instruction. + void instructionDecode(SimInstruction* instr); + // Execute one instruction placed in a branch delay slot. + void branchDelayInstructionDecode(SimInstruction* instr); + + public: + static int StopSimAt; + + // Runtime call support. + static void* RedirectNativeFunction(void* nativeFunction, + ABIFunctionType type); + + private: + enum Exception { + kNone, + kIntegerOverflow, + kIntegerUnderflow, + kDivideByZero, + kNumExceptions + }; + int16_t exceptions[kNumExceptions]; + + // Exceptions. + void signalExceptions(); + + // Handle arguments and return value for runtime FP functions. + void getFpArgs(double* x, double* y, int32_t* z); + void getFpFromStack(int32_t* stack, double* x); + + void setCallResultDouble(double result); + void setCallResultFloat(float result); + void setCallResult(int64_t res); + + void callInternal(uint8_t* entry); + + // Architecture state. + // Registers. + int32_t registers_[kNumSimuRegisters]; + // Coprocessor Registers. + int32_t FPUregisters_[kNumFPURegisters]; + // FPU control register. + uint32_t FCSR_; + + bool LLBit_; + uint32_t LLAddr_; + int32_t lastLLValue_; + + // Simulator support. + char* stack_; + uintptr_t stackLimit_; + bool pc_modified_; + int icount_; + int break_count_; + + // Debugger input. + char* lastDebuggerInput_; + + // Registered breakpoints. + SimInstruction* break_pc_; + Instr break_instr_; + + // Single-stepping support + bool single_stepping_; + SingleStepCallback single_step_callback_; + void* single_step_callback_arg_; + + // A stop is watched if its code is less than kNumOfWatchedStops. + // Only watched stops support enabling/disabling and the counter feature. + static const uint32_t kNumOfWatchedStops = 256; + + // Stop is disabled if bit 31 is set. + static const uint32_t kStopDisabledBit = 1U << 31; + + // A stop is enabled, meaning the simulator will stop when meeting the + // instruction, if bit 31 of watchedStops_[code].count is unset. + // The value watchedStops_[code].count & ~(1 << 31) indicates how many times + // the breakpoint was hit or gone through. + struct StopCountAndDesc { + uint32_t count_; + char* desc_; + }; + StopCountAndDesc watchedStops_[kNumOfWatchedStops]; +}; + +// Process wide simulator state. +class SimulatorProcess { + friend class Redirection; + friend class AutoLockSimulatorCache; + + private: + // ICache checking. + struct ICacheHasher { + typedef void* Key; + typedef void* Lookup; + static HashNumber hash(const Lookup& l); + static bool match(const Key& k, const Lookup& l); + }; + + public: + typedef HashMap<void*, CachePage*, ICacheHasher, SystemAllocPolicy> ICacheMap; + + static mozilla::Atomic<size_t, mozilla::ReleaseAcquire> + ICacheCheckingDisableCount; + static void FlushICache(void* start, size_t size); + + static void checkICacheLocked(SimInstruction* instr); + + static bool initialize() { + singleton_ = js_new<SimulatorProcess>(); + return singleton_; + } + static void destroy() { + js_delete(singleton_); + singleton_ = nullptr; + } + + SimulatorProcess(); + ~SimulatorProcess(); + + private: + static SimulatorProcess* singleton_; + + // This lock creates a critical section around 'redirection_' and + // 'icache_', which are referenced both by the execution engine + // and by the off-thread compiler (see Redirection::Get in the cpp file). + Mutex cacheLock_ MOZ_UNANNOTATED; + + Redirection* redirection_; + ICacheMap icache_; + + public: + static ICacheMap& icache() { + // Technically we need the lock to access the innards of the + // icache, not to take its address, but the latter condition + // serves as a useful complement to the former. + singleton_->cacheLock_.assertOwnedByCurrentThread(); + return singleton_->icache_; + } + + static Redirection* redirection() { + singleton_->cacheLock_.assertOwnedByCurrentThread(); + return singleton_->redirection_; + } + + static void setRedirection(js::jit::Redirection* redirection) { + singleton_->cacheLock_.assertOwnedByCurrentThread(); + singleton_->redirection_ = redirection; + } +}; + +} // namespace jit +} // namespace js + +#endif /* JS_SIMULATOR_MIPS32 */ + +#endif /* jit_mips32_Simulator_mips32_h */ |