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// Copyright 2014 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 PPC instructions if we are not generating a native
// PPC binary. This Simulator allows us to run and debug PPC 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 PPC HW platform.
#ifndef V8_PPC_SIMULATOR_PPC_H_
#define V8_PPC_SIMULATOR_PPC_H_
// globals.h defines USE_SIMULATOR.
#include "src/common/globals.h"
#if defined(USE_SIMULATOR)
// Running with a simulator.
#include "src/base/lazy-instance.h"
#include "src/base/platform/mutex.h"
#include "src/utils/allocation.h"
#include "src/base/hashmap.h"
#include "src/codegen/assembler.h"
#include "src/execution/simulator-base.h"
#include "src/ppc/constants-ppc.h"
namespace v8 {
namespace internal {
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 Simulator : public SimulatorBase {
public:
friend class PPCDebugger;
enum Register {
no_reg = -1,
r0 = 0,
sp,
r2,
r3,
r4,
r5,
r6,
r7,
r8,
r9,
r10,
r11,
r12,
r13,
r14,
r15,
r16,
r17,
r18,
r19,
r20,
r21,
r22,
r23,
r24,
r25,
r26,
r27,
r28,
r29,
r30,
fp,
kNumGPRs = 32,
d0 = 0,
d1,
d2,
d3,
d4,
d5,
d6,
d7,
d8,
d9,
d10,
d11,
d12,
d13,
d14,
d15,
d16,
d17,
d18,
d19,
d20,
d21,
d22,
d23,
d24,
d25,
d26,
d27,
d28,
d29,
d30,
d31,
kNumFPRs = 32
};
explicit Simulator(Isolate* isolate);
~Simulator();
// The currently executing Simulator instance. Potentially there can be one
// for each native thread.
static Simulator* current(v8::internal::Isolate* isolate);
// Accessors for register state.
void set_register(int reg, intptr_t value);
intptr_t get_register(int reg) const;
double get_double_from_register_pair(int reg);
void set_d_register_from_double(int dreg, const double dbl) {
DCHECK(dreg >= 0 && dreg < kNumFPRs);
*bit_cast<double*>(&fp_registers_[dreg]) = dbl;
}
double get_double_from_d_register(int dreg) {
DCHECK(dreg >= 0 && dreg < kNumFPRs);
return *bit_cast<double*>(&fp_registers_[dreg]);
}
void set_d_register(int dreg, int64_t value) {
DCHECK(dreg >= 0 && dreg < kNumFPRs);
fp_registers_[dreg] = value;
}
int64_t get_d_register(int dreg) {
DCHECK(dreg >= 0 && dreg < kNumFPRs);
return fp_registers_[dreg];
}
// Special case of set_register and get_register to access the raw PC value.
void set_pc(intptr_t value);
intptr_t get_pc() const;
Address get_sp() const { return static_cast<Address>(get_register(sp)); }
// Accessor to the internal Link Register
intptr_t get_lr() const;
// Accessor to the internal simulator stack area.
uintptr_t StackLimit(uintptr_t c_limit) const;
// Executes PPC 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.
void CallFP(Address entry, double d0, double d1);
int32_t CallFPReturnsInt(Address entry, double d0, double d1);
double CallFPReturnsDouble(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_lr, 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_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
};
intptr_t CallImpl(Address entry, int argument_count,
const intptr_t* arguments);
enum BCType { BC_OFFSET, BC_LINK_REG, BC_CTR_REG };
// Unsupported instructions use Format to print an error and stop execution.
void Format(Instruction* instr, const char* format);
// Helper functions to set the conditional flags in the architecture state.
bool CarryFrom(int32_t left, int32_t right, int32_t carry = 0);
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(Instruction* instr, bool* carry_out);
int32_t GetImm(Instruction* instr, bool* carry_out);
void ProcessPUW(Instruction* instr, int num_regs, int operand_size,
intptr_t* start_address, intptr_t* end_address);
void HandleRList(Instruction* instr, bool load);
void HandleVList(Instruction* inst);
void SoftwareInterrupt(Instruction* instr);
// Stop helper functions.
inline bool isStopInstruction(Instruction* instr);
inline bool isWatchedStop(uint32_t bkpt_code);
inline bool isEnabledStop(uint32_t bkpt_code);
inline void EnableStop(uint32_t bkpt_code);
inline void DisableStop(uint32_t bkpt_code);
inline void IncreaseStopCounter(uint32_t bkpt_code);
void PrintStopInfo(uint32_t code);
// Read and write memory.
template <typename T>
inline void Read(uintptr_t address, T* value) {
base::MutexGuard lock_guard(&GlobalMonitor::Get()->mutex);
memcpy(value, reinterpret_cast<const char*>(address), sizeof(T));
}
template <typename T>
inline void ReadEx(uintptr_t address, T* value) {
base::MutexGuard lock_guard(&GlobalMonitor::Get()->mutex);
GlobalMonitor::Get()->NotifyLoadExcl(
address, static_cast<TransactionSize>(sizeof(T)),
isolate_->thread_id());
memcpy(value, reinterpret_cast<const char*>(address), sizeof(T));
}
template <typename T>
inline void Write(uintptr_t address, T value) {
base::MutexGuard lock_guard(&GlobalMonitor::Get()->mutex);
GlobalMonitor::Get()->NotifyStore(address,
static_cast<TransactionSize>(sizeof(T)),
isolate_->thread_id());
memcpy(reinterpret_cast<char*>(address), &value, sizeof(T));
}
template <typename T>
inline int32_t WriteEx(uintptr_t address, T value) {
base::MutexGuard lock_guard(&GlobalMonitor::Get()->mutex);
if (GlobalMonitor::Get()->NotifyStoreExcl(
address, static_cast<TransactionSize>(sizeof(T)),
isolate_->thread_id())) {
memcpy(reinterpret_cast<char*>(address), &value, sizeof(T));
return 0;
} else {
return 1;
}
}
#define RW_VAR_LIST(V) \
V(DWU, uint64_t) \
V(DW, int64_t) \
V(WU, uint32_t) \
V(W, int32_t) V(HU, uint16_t) V(H, int16_t) V(BU, uint8_t) V(B, int8_t)
#define GENERATE_RW_FUNC(size, type) \
inline type Read##size(uintptr_t addr); \
inline type ReadEx##size(uintptr_t addr); \
inline void Write##size(uintptr_t addr, type value); \
inline int32_t WriteEx##size(uintptr_t addr, type value);
RW_VAR_LIST(GENERATE_RW_FUNC)
#undef GENERATE_RW_FUNC
void Trace(Instruction* instr);
void SetCR0(intptr_t result, bool setSO = false);
void ExecuteBranchConditional(Instruction* instr, BCType type);
void ExecuteGeneric(Instruction* instr);
void SetFPSCR(int bit) { fp_condition_reg_ |= (1 << (31 - bit)); }
void ClearFPSCR(int bit) { fp_condition_reg_ &= ~(1 << (31 - bit)); }
// Executes one instruction.
void ExecuteInstruction(Instruction* instr);
// 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);
// Handle arguments and return value for runtime FP functions.
void GetFpArgs(double* x, double* y, intptr_t* z);
void SetFpResult(const double& result);
void TrashCallerSaveRegisters();
void CallInternal(Address entry);
// Architecture state.
// Saturating instructions require a Q flag to indicate saturation.
// There is currently no way to read the CPSR directly, and thus read the Q
// flag, so this is left unimplemented.
intptr_t registers_[kNumGPRs];
int32_t condition_reg_;
int32_t fp_condition_reg_;
intptr_t special_reg_lr_;
intptr_t special_reg_pc_;
intptr_t special_reg_ctr_;
int32_t special_reg_xer_;
int64_t fp_registers_[kNumFPRs];
// Simulator support.
char* stack_;
static const size_t stack_protection_size_ = 256 * kPointerSize;
bool pc_modified_;
int icount_;
// Debugger input.
char* last_debugger_input_;
// Registered breakpoints.
Instruction* break_pc_;
Instr break_instr_;
v8::internal::Isolate* isolate_;
// 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;
// Breakpoint 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_[kNumOfWatchedStops];
// Synchronization primitives. See ARM DDI 0406C.b, A2.9.
enum class MonitorAccess {
Open,
Exclusive,
};
enum class TransactionSize {
None = 0,
Byte = 1,
HalfWord = 2,
Word = 4,
DWord = 8,
};
class GlobalMonitor {
public:
// Exposed so it can be accessed by Simulator::{Read,Write}Ex*.
base::Mutex mutex;
void NotifyLoadExcl(uintptr_t addr, TransactionSize size,
ThreadId thread_id);
void NotifyStore(uintptr_t addr, TransactionSize size, ThreadId thread_id);
bool NotifyStoreExcl(uintptr_t addr, TransactionSize size,
ThreadId thread_id);
static GlobalMonitor* Get();
private:
// Private constructor. Call {GlobalMonitor::Get()} to get the singleton.
GlobalMonitor() = default;
friend class base::LeakyObject<GlobalMonitor>;
void Clear();
MonitorAccess access_state_ = MonitorAccess::Open;
uintptr_t tagged_addr_ = 0;
TransactionSize size_ = TransactionSize::None;
ThreadId thread_id_ = ThreadId::Invalid();
};
};
} // namespace internal
} // namespace v8
#endif // defined(USE_SIMULATOR)
#endif // V8_PPC_SIMULATOR_PPC_H_