| // Copyright 2009 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. |
| |
| |
| // Declares a Simulator for ARM instructions if we are not generating a native |
| // ARM binary. This Simulator allows us to run and debug ARM code generation on |
| // regular desktop machines. |
| // V8 calls into generated code by "calling" the CALL_GENERATED_CODE macro, |
| // which will start execution in the Simulator or forwards to the real entry |
| // on a ARM HW platform. |
| |
| #ifndef V8_ARM_SIMULATOR_ARM_H_ |
| #define V8_ARM_SIMULATOR_ARM_H_ |
| |
| #include "allocation.h" |
| |
| #if defined(__arm__) |
| |
| // When running without a simulator we call the entry directly. |
| #define CALL_GENERATED_CODE(entry, p0, p1, p2, p3, p4) \ |
| (entry(p0, p1, p2, p3, p4)) |
| |
| // The stack limit beyond which we will throw stack overflow errors in |
| // generated code. Because generated code on arm uses the C stack, we |
| // just use the C stack limit. |
| class SimulatorStack : public v8::internal::AllStatic { |
| public: |
| static inline uintptr_t JsLimitFromCLimit(uintptr_t c_limit) { |
| return c_limit; |
| } |
| }; |
| |
| |
| // Call the generated regexp code directly. The entry function pointer should |
| // expect seven int/pointer sized arguments and return an int. |
| #define CALL_GENERATED_REGEXP_CODE(entry, p0, p1, p2, p3, p4, p5, p6) \ |
| entry(p0, p1, p2, p3, p4, p5, p6) |
| |
| #else // defined(__arm__) |
| |
| // When running with the simulator transition into simulated execution at this |
| // point. |
| #define CALL_GENERATED_CODE(entry, p0, p1, p2, p3, p4) \ |
| reinterpret_cast<Object*>( \ |
| assembler::arm::Simulator::current()->Call(FUNCTION_ADDR(entry), 5, \ |
| p0, p1, p2, p3, p4)) |
| |
| #define CALL_GENERATED_REGEXP_CODE(entry, p0, p1, p2, p3, p4, p5, p6) \ |
| assembler::arm::Simulator::current()->Call( \ |
| FUNCTION_ADDR(entry), 7, p0, p1, p2, p3, p4, p5, p6) |
| |
| #include "constants-arm.h" |
| |
| |
| namespace assembler { |
| namespace arm { |
| |
| class Simulator { |
| public: |
| friend class Debugger; |
| |
| enum Register { |
| no_reg = -1, |
| r0 = 0, r1, r2, r3, r4, r5, r6, r7, |
| r8, r9, r10, r11, r12, r13, r14, r15, |
| num_registers, |
| sp = 13, |
| lr = 14, |
| pc = 15 |
| }; |
| |
| Simulator(); |
| ~Simulator(); |
| |
| // The currently executing Simulator instance. Potentially there can be one |
| // for each native thread. |
| static Simulator* current(); |
| |
| // Accessors for register state. Reading the pc value adheres to the ARM |
| // architecture specification and is off by a 8 from the currently executing |
| // instruction. |
| void set_register(int reg, int32_t value); |
| int32_t get_register(int reg) const; |
| |
| // 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; |
| |
| // Accessor to the internal simulator stack area. |
| uintptr_t StackLimit() const; |
| |
| // Executes ARM instructions until the PC reaches end_sim_pc. |
| void Execute(); |
| |
| // Call on program start. |
| static void Initialize(); |
| |
| // V8 generally calls into generated JS code with 5 parameters and into |
| // generated RegExp code with 7 parameters. This is a convenience function, |
| // which sets up the simulator state and grabs the result on return. |
| int32_t Call(byte* entry, int argument_count, ...); |
| |
| private: |
| enum special_values { |
| // Known bad pc value to ensure that the simulator does not execute |
| // without being properly setup. |
| bad_lr = -1, |
| // A pc value used to signal the simulator to stop execution. Generally |
| // the lr 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 |
| }; |
| |
| // Unsupported instructions use Format to print an error and stop execution. |
| void Format(Instr* instr, const char* format); |
| |
| // Checks if the current instruction should be executed based on its |
| // condition bits. |
| bool ConditionallyExecute(Instr* instr); |
| |
| // Helper functions to set the conditional flags in the architecture state. |
| void SetNZFlags(int32_t val); |
| void SetCFlag(bool val); |
| void SetVFlag(bool val); |
| bool CarryFrom(int32_t left, int32_t right); |
| bool BorrowFrom(int32_t left, int32_t right); |
| bool OverflowFrom(int32_t alu_out, |
| int32_t left, |
| int32_t right, |
| bool addition); |
| |
| // Helper functions to decode common "addressing" modes |
| int32_t GetShiftRm(Instr* instr, bool* carry_out); |
| int32_t GetImm(Instr* instr, bool* carry_out); |
| void HandleRList(Instr* instr, bool load); |
| void SoftwareInterrupt(Instr* instr); |
| |
| // Read and write memory. |
| inline uint8_t ReadBU(int32_t addr); |
| inline int8_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, Instr* instr); |
| inline int16_t ReadH(int32_t addr, Instr* instr); |
| // Note: Overloaded on the sign of the value. |
| inline void WriteH(int32_t addr, uint16_t value, Instr* instr); |
| inline void WriteH(int32_t addr, int16_t value, Instr* instr); |
| |
| inline int ReadW(int32_t addr, Instr* instr); |
| inline void WriteW(int32_t addr, int value, Instr* instr); |
| |
| // Executing is handled based on the instruction type. |
| void DecodeType01(Instr* instr); // both type 0 and type 1 rolled into one |
| void DecodeType2(Instr* instr); |
| void DecodeType3(Instr* instr); |
| void DecodeType4(Instr* instr); |
| void DecodeType5(Instr* instr); |
| void DecodeType6(Instr* instr); |
| void DecodeType7(Instr* instr); |
| void DecodeUnconditional(Instr* instr); |
| |
| // Executes one instruction. |
| void InstructionDecode(Instr* instr); |
| |
| // Runtime call support. |
| static void* RedirectExternalReference(void* external_function, |
| bool fp_return); |
| |
| // For use in calls that take two double values, constructed from r0, r1, r2 |
| // and r3. |
| void GetFpArgs(double* x, double* y); |
| void SetFpResult(const double& result); |
| void TrashCallerSaveRegisters(); |
| |
| // architecture state |
| int32_t registers_[16]; |
| bool n_flag_; |
| bool z_flag_; |
| bool c_flag_; |
| bool v_flag_; |
| |
| // simulator support |
| char* stack_; |
| bool pc_modified_; |
| int icount_; |
| static bool initialized_; |
| |
| // registered breakpoints |
| Instr* break_pc_; |
| instr_t break_instr_; |
| }; |
| |
| } } // namespace assembler::arm |
| |
| |
| // The simulator has its own stack. Thus it has a different stack limit from |
| // the C-based native code. Setting the c_limit to indicate a very small |
| // stack cause stack overflow errors, since the simulator ignores the input. |
| // This is unlikely to be an issue in practice, though it might cause testing |
| // trouble down the line. |
| class SimulatorStack : public v8::internal::AllStatic { |
| public: |
| static inline uintptr_t JsLimitFromCLimit(uintptr_t c_limit) { |
| return assembler::arm::Simulator::current()->StackLimit(); |
| } |
| }; |
| |
| |
| #endif // defined(__arm__) |
| |
| #endif // V8_ARM_SIMULATOR_ARM_H_ |