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.
6 // Declares a Simulator for ARM instructions if we are not generating a native
7 // ARM binary. This Simulator allows us to run and debug ARM code generation on
8 // regular desktop machines.
9 // V8 calls into generated code by "calling" the CALL_GENERATED_CODE macro,
10 // which will start execution in the Simulator or forwards to the real entry
11 // on a ARM HW platform.
13 #ifndef V8_ARM_SIMULATOR_ARM_H_
14 #define V8_ARM_SIMULATOR_ARM_H_
16 #include "allocation.h"
18 #if !defined(USE_SIMULATOR)
19 // Running without a simulator on a native arm platform.
24 // When running without a simulator we call the entry directly.
25 #define CALL_GENERATED_CODE(entry, p0, p1, p2, p3, p4) \
26 (entry(p0, p1, p2, p3, p4))
28 typedef int (*arm_regexp_matcher)(String*, int, const byte*, const byte*,
29 void*, int*, int, Address, int, Isolate*);
32 // Call the generated regexp code directly. The code at the entry address
33 // should act as a function matching the type arm_regexp_matcher.
34 // The fifth argument is a dummy that reserves the space used for
35 // the return address added by the ExitFrame in native calls.
36 #define CALL_GENERATED_REGEXP_CODE(entry, p0, p1, p2, p3, p4, p5, p6, p7, p8) \
37 (FUNCTION_CAST<arm_regexp_matcher>(entry)( \
38 p0, p1, p2, p3, NULL, p4, p5, p6, p7, p8))
40 #define TRY_CATCH_FROM_ADDRESS(try_catch_address) \
41 reinterpret_cast<TryCatch*>(try_catch_address)
43 // The stack limit beyond which we will throw stack overflow errors in
44 // generated code. Because generated code on arm uses the C stack, we
45 // just use the C stack limit.
46 class SimulatorStack : public v8::internal::AllStatic {
48 static inline uintptr_t JsLimitFromCLimit(v8::internal::Isolate* isolate,
54 static inline uintptr_t RegisterCTryCatch(uintptr_t try_catch_address) {
55 return try_catch_address;
58 static inline void UnregisterCTryCatch() { }
61 } } // namespace v8::internal
63 #else // !defined(USE_SIMULATOR)
64 // Running with a simulator.
66 #include "constants-arm.h"
68 #include "assembler.h"
75 static const int LINE_VALID = 0;
76 static const int LINE_INVALID = 1;
78 static const int kPageShift = 12;
79 static const int kPageSize = 1 << kPageShift;
80 static const int kPageMask = kPageSize - 1;
81 static const int kLineShift = 2; // The cache line is only 4 bytes right now.
82 static const int kLineLength = 1 << kLineShift;
83 static const int kLineMask = kLineLength - 1;
86 memset(&validity_map_, LINE_INVALID, sizeof(validity_map_));
89 char* ValidityByte(int offset) {
90 return &validity_map_[offset >> kLineShift];
93 char* CachedData(int offset) {
94 return &data_[offset];
98 char data_[kPageSize]; // The cached data.
99 static const int kValidityMapSize = kPageSize >> kLineShift;
100 char validity_map_[kValidityMapSize]; // One byte per line.
106 friend class ArmDebugger;
109 r0 = 0, r1, r2, r3, r4, r5, r6, r7,
110 r8, r9, r10, r11, r12, r13, r14, r15,
115 s0 = 0, s1, s2, s3, s4, s5, s6, s7,
116 s8, s9, s10, s11, s12, s13, s14, s15,
117 s16, s17, s18, s19, s20, s21, s22, s23,
118 s24, s25, s26, s27, s28, s29, s30, s31,
119 num_s_registers = 32,
120 d0 = 0, d1, d2, d3, d4, d5, d6, d7,
121 d8, d9, d10, d11, d12, d13, d14, d15,
122 d16, d17, d18, d19, d20, d21, d22, d23,
123 d24, d25, d26, d27, d28, d29, d30, d31,
124 num_d_registers = 32,
125 q0 = 0, q1, q2, q3, q4, q5, q6, q7,
126 q8, q9, q10, q11, q12, q13, q14, q15,
130 explicit Simulator(Isolate* isolate);
133 // The currently executing Simulator instance. Potentially there can be one
134 // for each native thread.
135 static Simulator* current(v8::internal::Isolate* isolate);
137 // Accessors for register state. Reading the pc value adheres to the ARM
138 // architecture specification and is off by a 8 from the currently executing
140 void set_register(int reg, int32_t value);
141 int32_t get_register(int reg) const;
142 double get_double_from_register_pair(int reg);
143 void set_register_pair_from_double(int reg, double* value);
144 void set_dw_register(int dreg, const int* dbl);
147 void get_d_register(int dreg, uint64_t* value);
148 void set_d_register(int dreg, const uint64_t* value);
149 void get_d_register(int dreg, uint32_t* value);
150 void set_d_register(int dreg, const uint32_t* value);
151 void get_q_register(int qreg, uint64_t* value);
152 void set_q_register(int qreg, const uint64_t* value);
153 void get_q_register(int qreg, uint32_t* value);
154 void set_q_register(int qreg, const uint32_t* value);
156 void set_s_register(int reg, unsigned int value);
157 unsigned int get_s_register(int reg) const;
159 void set_d_register_from_double(int dreg, const double& dbl) {
160 SetVFPRegister<double, 2>(dreg, dbl);
163 double get_double_from_d_register(int dreg) {
164 return GetFromVFPRegister<double, 2>(dreg);
167 void set_s_register_from_float(int sreg, const float flt) {
168 SetVFPRegister<float, 1>(sreg, flt);
171 float get_float_from_s_register(int sreg) {
172 return GetFromVFPRegister<float, 1>(sreg);
175 void set_s_register_from_sinteger(int sreg, const int sint) {
176 SetVFPRegister<int, 1>(sreg, sint);
179 int get_sinteger_from_s_register(int sreg) {
180 return GetFromVFPRegister<int, 1>(sreg);
183 // Special case of set_register and get_register to access the raw PC value.
184 void set_pc(int32_t value);
185 int32_t get_pc() const;
188 return reinterpret_cast<Address>(static_cast<intptr_t>(get_register(sp)));
191 // Accessor to the internal simulator stack area.
192 uintptr_t StackLimit() const;
194 // Executes ARM instructions until the PC reaches end_sim_pc.
197 // Call on program start.
198 static void Initialize(Isolate* isolate);
200 // V8 generally calls into generated JS code with 5 parameters and into
201 // generated RegExp code with 7 parameters. This is a convenience function,
202 // which sets up the simulator state and grabs the result on return.
203 int32_t Call(byte* entry, int argument_count, ...);
204 // Alternative: call a 2-argument double function.
205 void CallFP(byte* entry, double d0, double d1);
206 int32_t CallFPReturnsInt(byte* entry, double d0, double d1);
207 double CallFPReturnsDouble(byte* entry, double d0, double d1);
209 // Push an address onto the JS stack.
210 uintptr_t PushAddress(uintptr_t address);
212 // Pop an address from the JS stack.
213 uintptr_t PopAddress();
216 void set_last_debugger_input(char* input);
217 char* last_debugger_input() { return last_debugger_input_; }
220 static void FlushICache(v8::internal::HashMap* i_cache, void* start,
223 // Returns true if pc register contains one of the 'special_values' defined
224 // below (bad_lr, end_sim_pc).
225 bool has_bad_pc() const;
227 // EABI variant for double arguments in use.
228 bool use_eabi_hardfloat() {
229 #if USE_EABI_HARDFLOAT
237 enum special_values {
238 // Known bad pc value to ensure that the simulator does not execute
239 // without being properly setup.
241 // A pc value used to signal the simulator to stop execution. Generally
242 // the lr is set to this value on transition from native C code to
243 // simulated execution, so that the simulator can "return" to the native
248 // Unsupported instructions use Format to print an error and stop execution.
249 void Format(Instruction* instr, const char* format);
251 // Checks if the current instruction should be executed based on its
253 inline bool ConditionallyExecute(Instruction* instr);
255 // Helper functions to set the conditional flags in the architecture state.
256 void SetNZFlags(int32_t val);
257 void SetCFlag(bool val);
258 void SetVFlag(bool val);
259 bool CarryFrom(int32_t left, int32_t right, int32_t carry = 0);
260 bool BorrowFrom(int32_t left, int32_t right);
261 bool OverflowFrom(int32_t alu_out,
266 inline int GetCarry() {
267 return c_flag_ ? 1 : 0;
271 void Compute_FPSCR_Flags(double val1, double val2);
272 void Copy_FPSCR_to_APSR();
273 inline double canonicalizeNaN(double value);
275 // Helper functions to decode common "addressing" modes
276 int32_t GetShiftRm(Instruction* instr, bool* carry_out);
277 int32_t GetImm(Instruction* instr, bool* carry_out);
278 int32_t ProcessPU(Instruction* instr,
281 intptr_t* start_address,
282 intptr_t* end_address);
283 void HandleRList(Instruction* instr, bool load);
284 void HandleVList(Instruction* inst);
285 void SoftwareInterrupt(Instruction* instr);
287 // Stop helper functions.
288 inline bool isStopInstruction(Instruction* instr);
289 inline bool isWatchedStop(uint32_t bkpt_code);
290 inline bool isEnabledStop(uint32_t bkpt_code);
291 inline void EnableStop(uint32_t bkpt_code);
292 inline void DisableStop(uint32_t bkpt_code);
293 inline void IncreaseStopCounter(uint32_t bkpt_code);
294 void PrintStopInfo(uint32_t code);
296 // Read and write memory.
297 inline uint8_t ReadBU(int32_t addr);
298 inline int8_t ReadB(int32_t addr);
299 inline void WriteB(int32_t addr, uint8_t value);
300 inline void WriteB(int32_t addr, int8_t value);
302 inline uint16_t ReadHU(int32_t addr, Instruction* instr);
303 inline int16_t ReadH(int32_t addr, Instruction* instr);
304 // Note: Overloaded on the sign of the value.
305 inline void WriteH(int32_t addr, uint16_t value, Instruction* instr);
306 inline void WriteH(int32_t addr, int16_t value, Instruction* instr);
308 inline int ReadW(int32_t addr, Instruction* instr);
309 inline void WriteW(int32_t addr, int value, Instruction* instr);
311 int32_t* ReadDW(int32_t addr);
312 void WriteDW(int32_t addr, int32_t value1, int32_t value2);
314 // Executing is handled based on the instruction type.
315 // Both type 0 and type 1 rolled into one.
316 void DecodeType01(Instruction* instr);
317 void DecodeType2(Instruction* instr);
318 void DecodeType3(Instruction* instr);
319 void DecodeType4(Instruction* instr);
320 void DecodeType5(Instruction* instr);
321 void DecodeType6(Instruction* instr);
322 void DecodeType7(Instruction* instr);
325 void DecodeTypeVFP(Instruction* instr);
326 void DecodeType6CoprocessorIns(Instruction* instr);
327 void DecodeSpecialCondition(Instruction* instr);
329 void DecodeVMOVBetweenCoreAndSinglePrecisionRegisters(Instruction* instr);
330 void DecodeVCMP(Instruction* instr);
331 void DecodeVCVTBetweenDoubleAndSingle(Instruction* instr);
332 void DecodeVCVTBetweenFloatingPointAndInteger(Instruction* instr);
334 // Executes one instruction.
335 void InstructionDecode(Instruction* instr);
338 static void CheckICache(v8::internal::HashMap* i_cache, Instruction* instr);
339 static void FlushOnePage(v8::internal::HashMap* i_cache, intptr_t start,
341 static CachePage* GetCachePage(v8::internal::HashMap* i_cache, void* page);
343 // Runtime call support.
344 static void* RedirectExternalReference(
345 void* external_function,
346 v8::internal::ExternalReference::Type type);
348 // Handle arguments and return value for runtime FP functions.
349 void GetFpArgs(double* x, double* y, int32_t* z);
350 void SetFpResult(const double& result);
351 void TrashCallerSaveRegisters();
353 template<class ReturnType, int register_size>
354 ReturnType GetFromVFPRegister(int reg_index);
356 template<class InputType, int register_size>
357 void SetVFPRegister(int reg_index, const InputType& value);
359 void CallInternal(byte* entry);
361 // Architecture state.
362 // Saturating instructions require a Q flag to indicate saturation.
363 // There is currently no way to read the CPSR directly, and thus read the Q
364 // flag, so this is left unimplemented.
365 int32_t registers_[16];
371 // VFP architecture state.
372 unsigned int vfp_registers_[num_d_registers * 2];
378 // VFP rounding mode. See ARM DDI 0406B Page A2-29.
379 VFPRoundingMode FPSCR_rounding_mode_;
380 bool FPSCR_default_NaN_mode_;
382 // VFP FP exception flags architecture state.
383 bool inv_op_vfp_flag_;
384 bool div_zero_vfp_flag_;
385 bool overflow_vfp_flag_;
386 bool underflow_vfp_flag_;
387 bool inexact_vfp_flag_;
389 // Simulator support.
395 char* last_debugger_input_;
398 v8::internal::HashMap* i_cache_;
400 // Registered breakpoints.
401 Instruction* break_pc_;
404 v8::internal::Isolate* isolate_;
406 // A stop is watched if its code is less than kNumOfWatchedStops.
407 // Only watched stops support enabling/disabling and the counter feature.
408 static const uint32_t kNumOfWatchedStops = 256;
410 // Breakpoint is disabled if bit 31 is set.
411 static const uint32_t kStopDisabledBit = 1 << 31;
413 // A stop is enabled, meaning the simulator will stop when meeting the
414 // instruction, if bit 31 of watched_stops_[code].count is unset.
415 // The value watched_stops_[code].count & ~(1 << 31) indicates how many times
416 // the breakpoint was hit or gone through.
417 struct StopCountAndDesc {
421 StopCountAndDesc watched_stops_[kNumOfWatchedStops];
425 // When running with the simulator transition into simulated execution at this
427 #define CALL_GENERATED_CODE(entry, p0, p1, p2, p3, p4) \
428 reinterpret_cast<Object*>(Simulator::current(Isolate::Current())->Call( \
429 FUNCTION_ADDR(entry), 5, p0, p1, p2, p3, p4))
431 #define CALL_GENERATED_FP_INT(entry, p0, p1) \
432 Simulator::current(Isolate::Current())->CallFPReturnsInt( \
433 FUNCTION_ADDR(entry), p0, p1)
435 #define CALL_GENERATED_REGEXP_CODE(entry, p0, p1, p2, p3, p4, p5, p6, p7, p8) \
436 Simulator::current(Isolate::Current())->Call( \
437 entry, 10, p0, p1, p2, p3, NULL, p4, p5, p6, p7, p8)
439 #define TRY_CATCH_FROM_ADDRESS(try_catch_address) \
440 try_catch_address == NULL ? \
441 NULL : *(reinterpret_cast<TryCatch**>(try_catch_address))
444 // The simulator has its own stack. Thus it has a different stack limit from
445 // the C-based native code. Setting the c_limit to indicate a very small
446 // stack cause stack overflow errors, since the simulator ignores the input.
447 // This is unlikely to be an issue in practice, though it might cause testing
448 // trouble down the line.
449 class SimulatorStack : public v8::internal::AllStatic {
451 static inline uintptr_t JsLimitFromCLimit(v8::internal::Isolate* isolate,
453 return Simulator::current(isolate)->StackLimit();
456 static inline uintptr_t RegisterCTryCatch(uintptr_t try_catch_address) {
457 Simulator* sim = Simulator::current(Isolate::Current());
458 return sim->PushAddress(try_catch_address);
461 static inline void UnregisterCTryCatch() {
462 Simulator::current(Isolate::Current())->PopAddress();
466 } } // namespace v8::internal
468 #endif // !defined(USE_SIMULATOR)
469 #endif // V8_ARM_SIMULATOR_ARM_H_