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cobalt / cobalt / db34c7d3df26d177bdae8398b50d968b7ec3fce3 / . / src / third_party / mozjs-45 / js / src / jit / arm / Simulator-arm.cpp
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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
// Copyright 2012 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.
#include "jit/arm/Simulator-arm.h"
#include "mozilla/Casting.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/FloatingPoint.h"
#include "mozilla/Likely.h"
#include "mozilla/MathAlgorithms.h"
#include "mozilla/SizePrintfMacros.h"
#include "asmjs/AsmJSValidate.h"
#include "jit/arm/Assembler-arm.h"
#include "jit/arm/disasm/Constants-arm.h"
#include "jit/AtomicOperations.h"
#include "vm/Runtime.h"
#include "vm/SharedMem.h"
extern "C" {
int64_t
__aeabi_idivmod(int x, int y)
{
uint32_t lo = uint32_t(x / y);
uint32_t hi = uint32_t(x % y);
return (int64_t(hi) << 32) | lo;
}
int64_t
__aeabi_uidivmod(int x, int y)
{
uint32_t lo = uint32_t(x) / uint32_t(y);
uint32_t hi = uint32_t(x) % uint32_t(y);
return (int64_t(hi) << 32) | lo;
}
}
namespace js {
namespace jit {
// Load/store multiple addressing mode.
enum BlockAddrMode {
// Alias modes for comparison when writeback does not matter.
da_x = (0|0|0) << 21, // Decrement after.
ia_x = (0|4|0) << 21, // Increment after.
db_x = (8|0|0) << 21, // Decrement before.
ib_x = (8|4|0) << 21, // Increment before.
};
// Type of VFP register. Determines register encoding.
enum VFPRegPrecision {
kSinglePrecision = 0,
kDoublePrecision = 1
};
enum NeonListType {
nlt_1 = 0x7,
nlt_2 = 0xA,
nlt_3 = 0x6,
nlt_4 = 0x2
};
// Supervisor Call (svc) specific support.
// Special Software Interrupt codes when used in the presence of the ARM
// simulator.
// svc (formerly swi) provides a 24bit immediate value. Use bits 22:0 for
// standard SoftwareInterrupCode. Bit 23 is reserved for the stop feature.
enum SoftwareInterruptCodes {
kCallRtRedirected = 0x10, // Transition to C code.
kBreakpoint= 0x20, // Breakpoint.
kStopCode = 1 << 23 // Stop.
};
const uint32_t kStopCodeMask = kStopCode - 1;
const uint32_t kMaxStopCode = kStopCode - 1;
// -----------------------------------------------------------------------------
// Instruction abstraction.
// The class Instruction enables access to individual fields defined in the ARM
// architecture instruction set encoding as described in figure A3-1.
// Note that the Assembler uses typedef int32_t Instr.
//
// Example: Test whether the instruction at ptr does set the condition code
// bits.
//
// bool InstructionSetsConditionCodes(byte* ptr) {
// Instruction* instr = Instruction::At(ptr);
// int type = instr->TypeValue();
// return ((type == 0) || (type == 1)) && instr->hasS();
// }
//
class SimInstruction {
public:
enum {
kInstrSize = 4,
kPCReadOffset = 8
};
// Get the raw instruction bits.
inline Instr instructionBits() const {
return *reinterpret_cast<const Instr*>(this);
}
// Set the raw instruction bits to value.
inline void setInstructionBits(Instr value) {
*reinterpret_cast<Instr*>(this) = value;
}
// Read one particular bit out of the instruction bits.
inline int bit(int nr) const {
return (instructionBits() >> nr) & 1;
}
// Read a bit field's value out of the instruction bits.
inline int bits(int hi, int lo) const {
return (instructionBits() >> lo) & ((2 << (hi - lo)) - 1);
}
// Read a bit field out of the instruction bits.
inline int bitField(int hi, int lo) const {
return instructionBits() & (((2 << (hi - lo)) - 1) << lo);
}
// Accessors for the different named fields used in the ARM encoding.
// The naming of these accessor corresponds to figure A3-1.
//
// Two kind of accessors are declared:
// - <Name>Field() will return the raw field, i.e. the field's bits at their
// original place in the instruction encoding.
// e.g. if instr is the 'addgt r0, r1, r2' instruction, encoded as
// 0xC0810002 conditionField(instr) will return 0xC0000000.
// - <Name>Value() will return the field value, shifted back to bit 0.
// e.g. if instr is the 'addgt r0, r1, r2' instruction, encoded as
// 0xC0810002 conditionField(instr) will return 0xC.
// Generally applicable fields
inline Assembler::ARMCondition conditionField() const {
return static_cast<Assembler::ARMCondition>(bitField(31, 28));
}
inline int typeValue() const { return bits(27, 25); }
inline int specialValue() const { return bits(27, 23); }
inline int rnValue() const { return bits(19, 16); }
inline int rdValue() const { return bits(15, 12); }
inline int coprocessorValue() const { return bits(11, 8); }
// Support for VFP.
// Vn(19-16) | Vd(15-12) | Vm(3-0)
inline int vnValue() const { return bits(19, 16); }
inline int vmValue() const { return bits(3, 0); }
inline int vdValue() const { return bits(15, 12); }
inline int nValue() const { return bit(7); }
inline int mValue() const { return bit(5); }
inline int dValue() const { return bit(22); }
inline int rtValue() const { return bits(15, 12); }
inline int pValue() const { return bit(24); }
inline int uValue() const { return bit(23); }
inline int opc1Value() const { return (bit(23) << 2) | bits(21, 20); }
inline int opc2Value() const { return bits(19, 16); }
inline int opc3Value() const { return bits(7, 6); }
inline int szValue() const { return bit(8); }
inline int VLValue() const { return bit(20); }
inline int VCValue() const { return bit(8); }
inline int VAValue() const { return bits(23, 21); }
inline int VBValue() const { return bits(6, 5); }
inline int VFPNRegValue(VFPRegPrecision pre) { return VFPGlueRegValue(pre, 16, 7); }
inline int VFPMRegValue(VFPRegPrecision pre) { return VFPGlueRegValue(pre, 0, 5); }
inline int VFPDRegValue(VFPRegPrecision pre) { return VFPGlueRegValue(pre, 12, 22); }
// Fields used in Data processing instructions.
inline int opcodeValue() const { return static_cast<ALUOp>(bits(24, 21)); }
inline ALUOp opcodeField() const { return static_cast<ALUOp>(bitField(24, 21)); }
inline int sValue() const { return bit(20); }
// With register.
inline int rmValue() const { return bits(3, 0); }
inline ShiftType shifttypeValue() const { return static_cast<ShiftType>(bits(6, 5)); }
inline int rsValue() const { return bits(11, 8); }
inline int shiftAmountValue() const { return bits(11, 7); }
// With immediate.
inline int rotateValue() const { return bits(11, 8); }
inline int immed8Value() const { return bits(7, 0); }
inline int immed4Value() const { return bits(19, 16); }
inline int immedMovwMovtValue() const { return immed4Value() << 12 | offset12Value(); }
// Fields used in Load/Store instructions.
inline int PUValue() const { return bits(24, 23); }
inline int PUField() const { return bitField(24, 23); }
inline int bValue() const { return bit(22); }
inline int wValue() const { return bit(21); }
inline int lValue() const { return bit(20); }
// With register uses same fields as Data processing instructions above with
// immediate.
inline int offset12Value() const { return bits(11, 0); }
// Multiple.
inline int rlistValue() const { return bits(15, 0); }
// Extra loads and stores.
inline int signValue() const { return bit(6); }
inline int hValue() const { return bit(5); }
inline int immedHValue() const { return bits(11, 8); }
inline int immedLValue() const { return bits(3, 0); }
// Fields used in Branch instructions.
inline int linkValue() const { return bit(24); }
inline int sImmed24Value() const { return ((instructionBits() << 8) >> 8); }
// Fields used in Software interrupt instructions.
inline SoftwareInterruptCodes svcValue() const {
return static_cast<SoftwareInterruptCodes>(bits(23, 0));
}
// Test for special encodings of type 0 instructions (extra loads and
// stores, as well as multiplications).
inline bool isSpecialType0() const { return (bit(7) == 1) && (bit(4) == 1); }
// Test for miscellaneous instructions encodings of type 0 instructions.
inline bool isMiscType0() const {
return bit(24) == 1 && bit(23) == 0 && bit(20) == 0 && (bit(7) == 0);
}
// Test for a nop instruction, which falls under type 1.
inline bool isNopType1() const { return bits(24, 0) == 0x0120F000; }
// Test for a stop instruction.
inline bool isStop() const {
return typeValue() == 7 && bit(24) == 1 && svcValue() >= kStopCode;
}
// Special accessors that test for existence of a value.
inline bool hasS() const { return sValue() == 1; }
inline bool hasB() const { return bValue() == 1; }
inline bool hasW() const { return wValue() == 1; }
inline bool hasL() const { return lValue() == 1; }
inline bool hasU() const { return uValue() == 1; }
inline bool hasSign() const { return signValue() == 1; }
inline bool hasH() const { return hValue() == 1; }
inline bool hasLink() const { return linkValue() == 1; }
// Decoding the double immediate in the vmov instruction.
double doubleImmedVmov() const;
// Decoding the float32 immediate in the vmov.f32 instruction.
float float32ImmedVmov() const;
private:
// Join split register codes, depending on single or double precision.
// four_bit is the position of the least-significant bit of the four
// bit specifier. one_bit is the position of the additional single bit
// specifier.
inline int VFPGlueRegValue(VFPRegPrecision pre, int four_bit, int one_bit) {
if (pre == kSinglePrecision)
return (bits(four_bit + 3, four_bit) << 1) | bit(one_bit);
return (bit(one_bit) << 4) | bits(four_bit + 3, four_bit);
}
SimInstruction() = delete;
SimInstruction(const SimInstruction& other) = delete;
void operator=(const SimInstruction& other) = delete;
};
double
SimInstruction::doubleImmedVmov() const
{
// Reconstruct a double from the immediate encoded in the vmov instruction.
//
// instruction: [xxxxxxxx,xxxxabcd,xxxxxxxx,xxxxefgh]
// double: [aBbbbbbb,bbcdefgh,00000000,00000000,
// 00000000,00000000,00000000,00000000]
//
// where B = ~b. Only the high 16 bits are affected.
uint64_t high16;
high16 = (bits(17, 16) << 4) | bits(3, 0); // xxxxxxxx,xxcdefgh.
high16 |= (0xff * bit(18)) << 6; // xxbbbbbb,bbxxxxxx.
high16 |= (bit(18) ^ 1) << 14; // xBxxxxxx,xxxxxxxx.
high16 |= bit(19) << 15; // axxxxxxx,xxxxxxxx.
uint64_t imm = high16 << 48;
return mozilla::BitwiseCast<double>(imm);
}
float
SimInstruction::float32ImmedVmov() const
{
// Reconstruct a float32 from the immediate encoded in the vmov instruction.
//
// instruction: [xxxxxxxx,xxxxabcd,xxxxxxxx,xxxxefgh]
// float32: [aBbbbbbc, defgh000, 00000000, 00000000]
//
// where B = ~b. Only the high 16 bits are affected.
uint32_t imm;
imm = (bits(17, 16) << 23) | (bits(3, 0) << 19); // xxxxxxxc,defgh000.0.0
imm |= (0x1f * bit(18)) << 25; // xxbbbbbx,xxxxxxxx.0.0
imm |= (bit(18) ^ 1) << 30; // xBxxxxxx,xxxxxxxx.0.0
imm |= bit(19) << 31; // axxxxxxx,xxxxxxxx.0.0
return mozilla::BitwiseCast<float>(imm);
}
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.
};
// Protects the icache() and redirection() properties of the
// Simulator.
class AutoLockSimulatorCache
{
public:
explicit AutoLockSimulatorCache(Simulator* sim) : sim_(sim) {
PR_Lock(sim_->cacheLock_);
MOZ_ASSERT(!sim_->cacheLockHolder_);
#ifdef DEBUG
sim_->cacheLockHolder_ = PR_GetCurrentThread();
#endif
}
~AutoLockSimulatorCache() {
MOZ_ASSERT(sim_->cacheLockHolder_);
#ifdef DEBUG
sim_->cacheLockHolder_ = nullptr;
#endif
PR_Unlock(sim_->cacheLock_);
}
private:
Simulator* const sim_;
};
bool Simulator::ICacheCheckingEnabled = false;
int64_t Simulator::StopSimAt = -1L;
Simulator*
Simulator::Create()
{
Simulator* sim = js_new<Simulator>();
if (!sim)
return nullptr;
if (!sim->init()) {
js_delete(sim);
return nullptr;
}
if (js_sb_getenv("ARM_SIM_ICACHE_CHECKS"))
Simulator::ICacheCheckingEnabled = true;
char* stopAtStr = js_sb_getenv("ARM_SIM_STOP_AT");
int64_t stopAt;
if (stopAtStr && sscanf(stopAtStr, "%lld", &stopAt) == 1) {
fprintf(stderr, "\nStopping simulation at icount %lld\n", stopAt);
Simulator::StopSimAt = stopAt;
}
return sim;
}
void
Simulator::Destroy(Simulator* sim)
{
js_delete(sim);
}
// The ArmDebugger class is used by the simulator while debugging simulated ARM
// code.
class ArmDebugger {
public:
explicit ArmDebugger(Simulator* sim) : sim_(sim) { }
void stop(SimInstruction* instr);
void debug();
private:
static const Instr kBreakpointInstr = (Assembler::AL | (7 * (1 << 25)) | (1* (1 << 24)) | kBreakpoint);
static const Instr kNopInstr = (Assembler::AL | (13 * (1 << 21)));
Simulator* sim_;
int32_t getRegisterValue(int regnum);
double getRegisterPairDoubleValue(int regnum);
double getVFPDoubleRegisterValue(int regnum);
bool getValue(const char* desc, int32_t* value);
bool getVFPDoubleValue(const char* desc, double* value);
// Set or delete a breakpoint. Returns true if successful.
bool setBreakpoint(SimInstruction* breakpc);
bool deleteBreakpoint(SimInstruction* breakpc);
// Undo and redo all breakpoints. This is needed to bracket disassembly and
// execution to skip past breakpoints when run from the debugger.
void undoBreakpoints();
void redoBreakpoints();
};
void
ArmDebugger::stop(SimInstruction * instr)
{
// Get the stop code.
uint32_t code = instr->svcValue() & kStopCodeMask;
// Retrieve the encoded address, which comes just after this stop.
char* msg = *reinterpret_cast<char**>(sim_->get_pc()
+ SimInstruction::kInstrSize);
// Update this stop description.
if (sim_->isWatchedStop(code) && !sim_->watched_stops_[code].desc) {
sim_->watched_stops_[code].desc = msg;
}
// Print the stop message and code if it is not the default code.
if (code != kMaxStopCode) {
printf("Simulator hit stop %u: %s\n", code, msg);
} else {
printf("Simulator hit %s\n", msg);
}
sim_->set_pc(sim_->get_pc() + 2 * SimInstruction::kInstrSize);
debug();
}
int32_t
ArmDebugger::getRegisterValue(int regnum)
{
if (regnum == Registers::pc)
return sim_->get_pc();
return sim_->get_register(regnum);
}
double
ArmDebugger::getRegisterPairDoubleValue(int regnum)
{
return sim_->get_double_from_register_pair(regnum);
}
double
ArmDebugger::getVFPDoubleRegisterValue(int regnum)
{
return sim_->get_double_from_d_register(regnum);
}
bool
ArmDebugger::getValue(const char* desc, int32_t* value)
{
Register reg = Register::FromName(desc);
if (reg != InvalidReg) {
*value = getRegisterValue(reg.code());
return true;
}
if (strncmp(desc, "0x", 2) == 0)
return sscanf(desc + 2, "%x", reinterpret_cast<uint32_t*>(value)) == 1;
return sscanf(desc, "%u", reinterpret_cast<uint32_t*>(value)) == 1;
}
bool
ArmDebugger::getVFPDoubleValue(const char* desc, double* value)
{
FloatRegister reg(FloatRegister::FromName(desc));
if (reg != InvalidFloatReg) {
*value = sim_->get_double_from_d_register(reg.code());
return true;
}
return false;
}
bool
ArmDebugger::setBreakpoint(SimInstruction* breakpc)
{
// Check if a breakpoint can be set. If not return without any side-effects.
if (sim_->break_pc_)
return false;
// Set the breakpoint.
sim_->break_pc_ = breakpc;
sim_->break_instr_ = breakpc->instructionBits();
// Not setting the breakpoint instruction in the code itself. It will be set
// when the debugger shell continues.
return true;
}
bool
ArmDebugger::deleteBreakpoint(SimInstruction* breakpc)
{
if (sim_->break_pc_ != nullptr)
sim_->break_pc_->setInstructionBits(sim_->break_instr_);
sim_->break_pc_ = nullptr;
sim_->break_instr_ = 0;
return true;
}
void
ArmDebugger::undoBreakpoints()
{
if (sim_->break_pc_)
sim_->break_pc_->setInstructionBits(sim_->break_instr_);
}
void
ArmDebugger::redoBreakpoints()
{
if (sim_->break_pc_)
sim_->break_pc_->setInstructionBits(kBreakpointInstr);
}
static char*
ReadLine(const char* prompt)
{
char* result = nullptr;
char line_buf[256];
int offset = 0;
bool keep_going = true;
fprintf(stdout, "%s", prompt);
fflush(stdout);
while (keep_going) {
if (fgets(line_buf, sizeof(line_buf), stdin) == nullptr) {
// fgets got an error. Just give up.
if (result)
js_delete(result);
return nullptr;
}
int len = strlen(line_buf);
if (len > 0 && line_buf[len - 1] == '\n') {
// Since we read a new line we are done reading the line. This will
// exit the loop after copying this buffer into the result.
keep_going = false;
}
if (!result) {
// Allocate the initial result and make room for the terminating
// '\0'.
result = (char*)js_malloc(len + 1);
if (!result)
return nullptr;
} else {
// Allocate a new result with enough room for the new addition.
int new_len = offset + len + 1;
char* new_result = (char*)js_malloc(new_len);
if (!new_result)
return nullptr;
// Copy the existing input into the new array and set the new
// array as the result.
memcpy(new_result, result, offset * sizeof(char));
js_free(result);
result = new_result;
}
// Copy the newly read line into the result.
memcpy(result + offset, line_buf, len * sizeof(char));
offset += len;
}
MOZ_ASSERT(result);
result[offset] = '\0';
return result;
}
void
ArmDebugger::debug()
{
intptr_t last_pc = -1;
bool done = false;
#define COMMAND_SIZE 63
#define ARG_SIZE 255
#define STR(a) #a
#define XSTR(a) STR(a)
char cmd[COMMAND_SIZE + 1];
char arg1[ARG_SIZE + 1];
char arg2[ARG_SIZE + 1];
char* argv[3] = { cmd, arg1, arg2 };
// Make sure to have a proper terminating character if reaching the limit.
cmd[COMMAND_SIZE] = 0;
arg1[ARG_SIZE] = 0;
arg2[ARG_SIZE] = 0;
// Undo all set breakpoints while running in the debugger shell. This will
// make them invisible to all commands.
undoBreakpoints();
#ifndef JS_DISASM_ARM
static bool disasm_warning_printed = false;
if (!disasm_warning_printed) {
printf(" No ARM disassembler present. Enable JS_DISASM_ARM in configure.in.");
disasm_warning_printed = true;
}
#endif
while (!done && !sim_->has_bad_pc()) {
if (last_pc != sim_->get_pc()) {
#ifdef JS_DISASM_ARM
disasm::NameConverter converter;
disasm::Disassembler dasm(converter);
disasm::EmbeddedVector<char, disasm::ReasonableBufferSize> buffer;
dasm.InstructionDecode(buffer,
reinterpret_cast<uint8_t*>(sim_->get_pc()));
printf(" 0x%08x %s\n", sim_->get_pc(), buffer.start());
#endif
last_pc = sim_->get_pc();
}
char* line = ReadLine("sim> ");
if (line == nullptr) {
break;
} else {
char* last_input = sim_->lastDebuggerInput();
if (strcmp(line, "\n") == 0 && last_input != nullptr) {
line = last_input;
} else {
// Ownership is transferred to sim_;
sim_->setLastDebuggerInput(line);
}
// Use sscanf to parse the individual parts of the command line. At the
// moment no command expects more than two parameters.
int argc = sscanf(line,
"%" XSTR(COMMAND_SIZE) "s "
"%" XSTR(ARG_SIZE) "s "
"%" XSTR(ARG_SIZE) "s",
cmd, arg1, arg2);
if (argc < 0) {
continue;
} else if ((strcmp(cmd, "si") == 0) || (strcmp(cmd, "stepi") == 0)) {
sim_->instructionDecode(reinterpret_cast<SimInstruction*>(sim_->get_pc()));
sim_->icount_++;
} else if ((strcmp(cmd, "skip") == 0)) {
sim_->set_pc(sim_->get_pc() + 4);
sim_->icount_++;
} else if ((strcmp(cmd, "c") == 0) || (strcmp(cmd, "cont") == 0)) {
// Execute the one instruction we broke at with breakpoints
// disabled.
sim_->instructionDecode(reinterpret_cast<SimInstruction*>(sim_->get_pc()));
sim_->icount_++;
// Leave the debugger shell.
done = true;
} else if ((strcmp(cmd, "p") == 0) || (strcmp(cmd, "print") == 0)) {
if (argc == 2 || (argc == 3 && strcmp(arg2, "fp") == 0)) {
int32_t value;
double dvalue;
if (strcmp(arg1, "all") == 0) {
for (uint32_t i = 0; i < Registers::Total; i++) {
value = getRegisterValue(i);
printf("%3s: 0x%08x %10d", Registers::GetName(i), value, value);
if ((argc == 3 && strcmp(arg2, "fp") == 0) &&
i < 8 &&
(i % 2) == 0) {
dvalue = getRegisterPairDoubleValue(i);
printf(" (%.16g)\n", dvalue);
} else {
printf("\n");
}
}
for (uint32_t i = 0; i < FloatRegisters::TotalPhys; i++) {
dvalue = getVFPDoubleRegisterValue(i);
uint64_t as_words = mozilla::BitwiseCast<uint64_t>(dvalue);
printf("%3s: %.16g 0x%08x %08x\n",
FloatRegister::FromCode(i).name(),
dvalue,
static_cast<uint32_t>(as_words >> 32),
static_cast<uint32_t>(as_words & 0xffffffff));
}
} else {
if (getValue(arg1, &value)) {
printf("%s: 0x%08x %d \n", arg1, value, value);
} else if (getVFPDoubleValue(arg1, &dvalue)) {
uint64_t as_words = mozilla::BitwiseCast<uint64_t>(dvalue);
printf("%s: %.16g 0x%08x %08x\n",
arg1,
dvalue,
static_cast<uint32_t>(as_words >> 32),
static_cast<uint32_t>(as_words & 0xffffffff));
} else {
printf("%s unrecognized\n", arg1);
}
}
} else {
printf("print <register>\n");
}
} else if (strcmp(cmd, "stack") == 0 || strcmp(cmd, "mem") == 0) {
int32_t* cur = nullptr;
int32_t* end = nullptr;
int next_arg = 1;
if (strcmp(cmd, "stack") == 0) {
cur = reinterpret_cast<int32_t*>(sim_->get_register(Simulator::sp));
} else { // "mem"
int32_t value;
if (!getValue(arg1, &value)) {
printf("%s unrecognized\n", arg1);
continue;
}
cur = reinterpret_cast<int32_t*>(value);
next_arg++;
}
int32_t words;
if (argc == next_arg) {
words = 10;
} else {
if (!getValue(argv[next_arg], &words)) {
words = 10;
}
}
end = cur + words;
while (cur < end) {
printf(" %p: 0x%08x %10d", cur, *cur, *cur);
printf("\n");
cur++;
}
} else if (strcmp(cmd, "disasm") == 0 || strcmp(cmd, "di") == 0) {
#ifdef JS_DISASM_ARM
uint8_t* prev = nullptr;
uint8_t* cur = nullptr;
uint8_t* end = nullptr;
if (argc == 1) {
cur = reinterpret_cast<uint8_t*>(sim_->get_pc());
end = cur + (10 * SimInstruction::kInstrSize);
} else if (argc == 2) {
Register reg = Register::FromName(arg1);
if (reg != InvalidReg || strncmp(arg1, "0x", 2) == 0) {
// The argument is an address or a register name.
int32_t value;
if (getValue(arg1, &value)) {
cur = reinterpret_cast<uint8_t*>(value);
// Disassemble 10 instructions at <arg1>.
end = cur + (10 * SimInstruction::kInstrSize);
}
} else {
// The argument is the number of instructions.
int32_t value;
if (getValue(arg1, &value)) {
cur = reinterpret_cast<uint8_t*>(sim_->get_pc());
// Disassemble <arg1> instructions.
end = cur + (value * SimInstruction::kInstrSize);
}
}
} else {
int32_t value1;
int32_t value2;
if (getValue(arg1, &value1) && getValue(arg2, &value2)) {
cur = reinterpret_cast<uint8_t*>(value1);
end = cur + (value2 * SimInstruction::kInstrSize);
}
}
while (cur < end) {
disasm::NameConverter converter;
disasm::Disassembler dasm(converter);
disasm::EmbeddedVector<char, disasm::ReasonableBufferSize> buffer;
prev = cur;
cur += dasm.InstructionDecode(buffer, cur);
printf(" 0x%08x %s\n", reinterpret_cast<uint32_t>(prev), buffer.start());
}
#endif
} else if (strcmp(cmd, "gdb") == 0) {
printf("relinquishing control to gdb\n");
asm("int $3");
printf("regaining control from gdb\n");
} else if (strcmp(cmd, "break") == 0) {
if (argc == 2) {
int32_t value;
if (getValue(arg1, &value)) {
if (!setBreakpoint(reinterpret_cast<SimInstruction*>(value)))
printf("setting breakpoint failed\n");
} else {
printf("%s unrecognized\n", arg1);
}
} else {
printf("break <address>\n");
}
} else if (strcmp(cmd, "del") == 0) {
if (!deleteBreakpoint(nullptr)) {
printf("deleting breakpoint failed\n");
}
} else if (strcmp(cmd, "flags") == 0) {
printf("N flag: %d; ", sim_->n_flag_);
printf("Z flag: %d; ", sim_->z_flag_);
printf("C flag: %d; ", sim_->c_flag_);
printf("V flag: %d\n", sim_->v_flag_);
printf("INVALID OP flag: %d; ", sim_->inv_op_vfp_flag_);
printf("DIV BY ZERO flag: %d; ", sim_->div_zero_vfp_flag_);
printf("OVERFLOW flag: %d; ", sim_->overflow_vfp_flag_);
printf("UNDERFLOW flag: %d; ", sim_->underflow_vfp_flag_);
printf("INEXACT flag: %d;\n", sim_->inexact_vfp_flag_);
} else if (strcmp(cmd, "stop") == 0) {
int32_t value;
intptr_t stop_pc = sim_->get_pc() - 2 * SimInstruction::kInstrSize;
SimInstruction* stop_instr = reinterpret_cast<SimInstruction*>(stop_pc);
SimInstruction* msg_address =
reinterpret_cast<SimInstruction*>(stop_pc + SimInstruction::kInstrSize);
if ((argc == 2) && (strcmp(arg1, "unstop") == 0)) {
// Remove the current stop.
if (sim_->isStopInstruction(stop_instr)) {
stop_instr->setInstructionBits(kNopInstr);
msg_address->setInstructionBits(kNopInstr);
} else {
printf("Not at debugger stop.\n");
}
} else if (argc == 3) {
// Print information about all/the specified breakpoint(s).
if (strcmp(arg1, "info") == 0) {
if (strcmp(arg2, "all") == 0) {
printf("Stop information:\n");
for (uint32_t i = 0; i < sim_->kNumOfWatchedStops; i++)
sim_->printStopInfo(i);
} else if (getValue(arg2, &value)) {
sim_->printStopInfo(value);
} else {
printf("Unrecognized argument.\n");
}
} else if (strcmp(arg1, "enable") == 0) {
// Enable all/the specified breakpoint(s).
if (strcmp(arg2, "all") == 0) {
for (uint32_t i = 0; i < sim_->kNumOfWatchedStops; i++)
sim_->enableStop(i);
} else if (getValue(arg2, &value)) {
sim_->enableStop(value);
} else {
printf("Unrecognized argument.\n");
}
} else if (strcmp(arg1, "disable") == 0) {
// Disable all/the specified breakpoint(s).
if (strcmp(arg2, "all") == 0) {
for (uint32_t i = 0; i < sim_->kNumOfWatchedStops; i++) {
sim_->disableStop(i);
}
} else if (getValue(arg2, &value)) {
sim_->disableStop(value);
} else {
printf("Unrecognized argument.\n");
}
}
} else {
printf("Wrong usage. Use help command for more information.\n");
}
} else if ((strcmp(cmd, "h") == 0) || (strcmp(cmd, "help") == 0)) {
printf("cont\n");
printf(" continue execution (alias 'c')\n");
printf("skip\n");
printf(" skip one instruction (set pc to next instruction)\n");
printf("stepi\n");
printf(" step one instruction (alias 'si')\n");
printf("print <register>\n");
printf(" print register content (alias 'p')\n");
printf(" use register name 'all' to print all registers\n");
printf(" add argument 'fp' to print register pair double values\n");
printf("flags\n");
printf(" print flags\n");
printf("stack [<words>]\n");
printf(" dump stack content, default dump 10 words)\n");
printf("mem <address> [<words>]\n");
printf(" dump memory content, default dump 10 words)\n");
printf("disasm [<instructions>]\n");
printf("disasm [<address/register>]\n");
printf("disasm [[<address/register>] <instructions>]\n");
printf(" disassemble code, default is 10 instructions\n");
printf(" from pc (alias 'di')\n");
printf("gdb\n");
printf(" enter gdb\n");
printf("break <address>\n");
printf(" set a break point on the address\n");
printf("del\n");
printf(" delete the breakpoint\n");
printf("stop feature:\n");
printf(" Description:\n");
printf(" Stops are debug instructions inserted by\n");
printf(" the Assembler::stop() function.\n");
printf(" When hitting a stop, the Simulator will\n");
printf(" stop and and give control to the ArmDebugger.\n");
printf(" The first %d stop codes are watched:\n",
Simulator::kNumOfWatchedStops);
printf(" - They can be enabled / disabled: the Simulator\n");
printf(" will / won't stop when hitting them.\n");
printf(" - The Simulator keeps track of how many times they \n");
printf(" are met. (See the info command.) Going over a\n");
printf(" disabled stop still increases its counter. \n");
printf(" Commands:\n");
printf(" stop info all/<code> : print infos about number <code>\n");
printf(" or all stop(s).\n");
printf(" stop enable/disable all/<code> : enables / disables\n");
printf(" all or number <code> stop(s)\n");
printf(" stop unstop\n");
printf(" ignore the stop instruction at the current location\n");
printf(" from now on\n");
} else {
printf("Unknown command: %s\n", cmd);
}
}
}
// Add all the breakpoints back to stop execution and enter the debugger
// shell when hit.
redoBreakpoints();
#undef COMMAND_SIZE
#undef ARG_SIZE
#undef STR
#undef XSTR
}
static bool
AllOnOnePage(uintptr_t start, int size)
{
intptr_t start_page = (start & ~CachePage::kPageMask);
intptr_t end_page = ((start + size) & ~CachePage::kPageMask);
return start_page == end_page;
}
static CachePage*
GetCachePageLocked(Simulator::ICacheMap& i_cache, void* page)
{
MOZ_ASSERT(Simulator::ICacheCheckingEnabled);
Simulator::ICacheMap::AddPtr p = i_cache.lookupForAdd(page);
if (p)
return p->value();
AutoEnterOOMUnsafeRegion oomUnsafe;
CachePage* new_page = js_new<CachePage>();
if (!new_page || !i_cache.add(p, page, new_page))
oomUnsafe.crash("Simulator CachePage");
return new_page;
}
// Flush from start up to and not including start + size.
static void
FlushOnePageLocked(Simulator::ICacheMap& i_cache, intptr_t start, int size)
{
MOZ_ASSERT(size <= CachePage::kPageSize);
MOZ_ASSERT(AllOnOnePage(start, size - 1));
MOZ_ASSERT((start & CachePage::kLineMask) == 0);
MOZ_ASSERT((size & CachePage::kLineMask) == 0);
void* page = reinterpret_cast<void*>(start & (~CachePage::kPageMask));
int offset = (start & CachePage::kPageMask);
CachePage* cache_page = GetCachePageLocked(i_cache, page);
char* valid_bytemap = cache_page->validityByte(offset);
memset(valid_bytemap, CachePage::LINE_INVALID, size >> CachePage::kLineShift);
}
static void
FlushICacheLocked(Simulator::ICacheMap& i_cache, void* start_addr, size_t size)
{
intptr_t start = reinterpret_cast<intptr_t>(start_addr);
int intra_line = (start & CachePage::kLineMask);
start -= intra_line;
size += intra_line;
size = ((size - 1) | CachePage::kLineMask) + 1;
int offset = (start & CachePage::kPageMask);
while (!AllOnOnePage(start, size - 1)) {
int bytes_to_flush = CachePage::kPageSize - offset;
FlushOnePageLocked(i_cache, start, bytes_to_flush);
start += bytes_to_flush;
size -= bytes_to_flush;
MOZ_ASSERT((start & CachePage::kPageMask) == 0);
offset = 0;
}
if (size != 0)
FlushOnePageLocked(i_cache, start, size);
}
static void
CheckICacheLocked(Simulator::ICacheMap& i_cache, SimInstruction* instr)
{
intptr_t address = reinterpret_cast<intptr_t>(instr);
void* page = reinterpret_cast<void*>(address & (~CachePage::kPageMask));
void* line = reinterpret_cast<void*>(address & (~CachePage::kLineMask));
int offset = (address & CachePage::kPageMask);
CachePage* cache_page = GetCachePageLocked(i_cache, page);
char* cache_valid_byte = cache_page->validityByte(offset);
bool cache_hit = (*cache_valid_byte == CachePage::LINE_VALID);
char* cached_line = cache_page->cachedData(offset & ~CachePage::kLineMask);
if (cache_hit) {
// Check that the data in memory matches the contents of the I-cache.
MOZ_ASSERT(memcmp(reinterpret_cast<void*>(instr),
cache_page->cachedData(offset),
SimInstruction::kInstrSize) == 0);
} else {
// Cache miss. Load memory into the cache.
memcpy(cached_line, line, CachePage::kLineLength);
*cache_valid_byte = CachePage::LINE_VALID;
}
}
HashNumber
Simulator::ICacheHasher::hash(const Lookup& l)
{
return static_cast<uint32_t>(reinterpret_cast<uintptr_t>(l)) >> 2;
}
bool
Simulator::ICacheHasher::match(const Key& k, const Lookup& l)
{
MOZ_ASSERT((reinterpret_cast<intptr_t>(k) & CachePage::kPageMask) == 0);
MOZ_ASSERT((reinterpret_cast<intptr_t>(l) & CachePage::kPageMask) == 0);
return k == l;
}
void
Simulator::setLastDebuggerInput(char* input)
{
js_free(lastDebuggerInput_);
lastDebuggerInput_ = input;
}
void
Simulator::FlushICache(void* start_addr, size_t size)
{
JitSpewCont(JitSpew_CacheFlush, "[%p %" PRIxSIZE "]", start_addr, size);
if (Simulator::ICacheCheckingEnabled) {
Simulator* sim = Simulator::Current();
AutoLockSimulatorCache als(sim);
js::jit::FlushICacheLocked(sim->icache(), start_addr, size);
}
}
Simulator::Simulator()
{
// Set up simulator support first. Some of this information is needed to
// setup the architecture state.
// Note, allocation and anything that depends on allocated memory is
// deferred until init(), in order to handle OOM properly.
stack_ = nullptr;
stackLimit_ = 0;
pc_modified_ = false;
icount_ = 0L;
resume_pc_ = 0;
break_pc_ = nullptr;
break_instr_ = 0;
single_stepping_ = false;
single_step_callback_ = nullptr;
single_step_callback_arg_ = nullptr;
skipCalleeSavedRegsCheck = false;
// Set up architecture state.
// All registers are initialized to zero to start with.
for (int i = 0; i < num_registers; i++)
registers_[i] = 0;
n_flag_ = false;
z_flag_ = false;
c_flag_ = false;
v_flag_ = false;
for (int i = 0; i < num_d_registers * 2; i++)
vfp_registers_[i] = 0;
n_flag_FPSCR_ = false;
z_flag_FPSCR_ = false;
c_flag_FPSCR_ = false;
v_flag_FPSCR_ = false;
FPSCR_rounding_mode_ = SimRZ;
FPSCR_default_NaN_mode_ = true;
inv_op_vfp_flag_ = false;
div_zero_vfp_flag_ = false;
overflow_vfp_flag_ = false;
underflow_vfp_flag_ = false;
inexact_vfp_flag_ = false;
// The lr and pc are initialized to a known bad value that will cause an
// access violation if the simulator ever tries to execute it.
registers_[pc] = bad_lr;
registers_[lr] = bad_lr;
lastDebuggerInput_ = nullptr;
cacheLock_ = nullptr;
#ifdef DEBUG
cacheLockHolder_ = nullptr;
#endif
redirection_ = nullptr;
exclusiveMonitorHeld_ = false;
exclusiveMonitor_ = 0;
}
bool
Simulator::init()
{
cacheLock_ = PR_NewLock();
if (!cacheLock_)
return false;
if (!icache_.init())
return false;
// Allocate 2MB for the stack. Note that we will only use 1MB, see below.
static const size_t stackSize = 2 * 1024*1024;
stack_ = reinterpret_cast<char*>(js_malloc(stackSize));
if (!stack_)
return false;
// Leave a safety margin of 1MB to prevent overrunning the stack when
// pushing values (total stack size is 2MB).
stackLimit_ = reinterpret_cast<uintptr_t>(stack_) + 1024 * 1024;
// The sp is initialized to point to the bottom (high address) of the
// allocated stack area. To be safe in potential stack underflows we leave
// some buffer below.
registers_[sp] = reinterpret_cast<int32_t>(stack_) + stackSize - 64;
return true;
}
// When the generated code calls a VM function (masm.callWithABI) we need to
// call that function instead of trying to execute it with the simulator
// (because it's x86 code instead of arm code). We do that by redirecting the VM
// call to a svc (Supervisor Call) instruction that is handled by the
// simulator. We write the original destination of the jump just at a known
// offset from the svc instruction so the simulator knows what to call.
class Redirection
{
friend class Simulator;
// sim's lock must already be held.
Redirection(void* nativeFunction, ABIFunctionType type, Simulator* sim)
: nativeFunction_(nativeFunction),
swiInstruction_(Assembler::AL | (0xf * (1 << 24)) | kCallRtRedirected),
type_(type),
next_(nullptr)
{
next_ = sim->redirection();
if (Simulator::ICacheCheckingEnabled)
FlushICacheLocked(sim->icache(), addressOfSwiInstruction(), SimInstruction::kInstrSize);
sim->setRedirection(this);
}
public:
void* addressOfSwiInstruction() { return &swiInstruction_; }
void* nativeFunction() const { return nativeFunction_; }
ABIFunctionType type() const { return type_; }
static Redirection* Get(void* nativeFunction, ABIFunctionType type) {
Simulator* sim = Simulator::Current();
AutoLockSimulatorCache als(sim);
Redirection* current = sim->redirection();
for (; current != nullptr; current = current->next_) {
if (current->nativeFunction_ == nativeFunction) {
MOZ_ASSERT(current->type() == type);
return current;
}
}
AutoEnterOOMUnsafeRegion oomUnsafe;
Redirection* redir = (Redirection*)js_malloc(sizeof(Redirection));
if (!redir)
oomUnsafe.crash("Simulator redirection");
new(redir) Redirection(nativeFunction, type, sim);
return redir;
}
static Redirection* FromSwiInstruction(SimInstruction* swiInstruction) {
uint8_t* addrOfSwi = reinterpret_cast<uint8_t*>(swiInstruction);
uint8_t* addrOfRedirection = addrOfSwi - offsetof(Redirection, swiInstruction_);
return reinterpret_cast<Redirection*>(addrOfRedirection);
}
private:
void* nativeFunction_;
uint32_t swiInstruction_;
ABIFunctionType type_;
Redirection* next_;
};
Simulator::~Simulator()
{
js_free(stack_);
PR_DestroyLock(cacheLock_);
Redirection* r = redirection_;
while (r) {
Redirection* next = r->next_;
js_delete(r);
r = next;
}
}
/* static */ void*
Simulator::RedirectNativeFunction(void* nativeFunction, ABIFunctionType type)
{
Redirection* redirection = Redirection::Get(nativeFunction, type);
return redirection->addressOfSwiInstruction();
}
// Sets the register in the architecture state. It will also deal with updating
// Simulator internal state for special registers such as PC.
void
Simulator::set_register(int reg, int32_t value)
{
MOZ_ASSERT(reg >= 0 && reg < num_registers);
if (reg == pc)
pc_modified_ = true;
registers_[reg] = value;
}
// Get the register from the architecture state. This function does handle the
// special case of accessing the PC register.
int32_t
Simulator::get_register(int reg) const
{
MOZ_ASSERT(reg >= 0 && reg < num_registers);
// Work around GCC bug: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43949
if (reg >= num_registers) return 0;
return registers_[reg] + ((reg == pc) ? SimInstruction::kPCReadOffset : 0);
}
double
Simulator::get_double_from_register_pair(int reg)
{
MOZ_ASSERT(reg >= 0 && reg < num_registers && (reg % 2) == 0);
// Read the bits from the unsigned integer register_[] array into the double
// precision floating point value and return it.
double dm_val = 0.0;
char buffer[2 * sizeof(vfp_registers_[0])];
memcpy(buffer, &registers_[reg], 2 * sizeof(registers_[0]));
memcpy(&dm_val, buffer, 2 * sizeof(registers_[0]));
return dm_val;
}
void
Simulator::set_register_pair_from_double(int reg, double* value)
{
MOZ_ASSERT(reg >= 0 && reg < num_registers && (reg % 2) == 0);
memcpy(registers_ + reg, value, sizeof(*value));
}
void
Simulator::set_dw_register(int dreg, const int* dbl)
{
MOZ_ASSERT(dreg >= 0 && dreg < num_d_registers);
registers_[dreg] = dbl[0];
registers_[dreg + 1] = dbl[1];
}
void
Simulator::get_d_register(int dreg, uint64_t* value)
{
MOZ_ASSERT(dreg >= 0 && dreg < int(FloatRegisters::TotalPhys));
memcpy(value, vfp_registers_ + dreg * 2, sizeof(*value));
}
void
Simulator::set_d_register(int dreg, const uint64_t* value)
{
MOZ_ASSERT(dreg >= 0 && dreg < int(FloatRegisters::TotalPhys));
memcpy(vfp_registers_ + dreg * 2, value, sizeof(*value));
}
void
Simulator::get_d_register(int dreg, uint32_t* value)
{
MOZ_ASSERT(dreg >= 0 && dreg < int(FloatRegisters::TotalPhys));
memcpy(value, vfp_registers_ + dreg * 2, sizeof(*value) * 2);
}
void
Simulator::set_d_register(int dreg, const uint32_t* value)
{
MOZ_ASSERT(dreg >= 0 && dreg < int(FloatRegisters::TotalPhys));
memcpy(vfp_registers_ + dreg * 2, value, sizeof(*value) * 2);
}
void
Simulator::get_q_register(int qreg, uint64_t* value)
{
MOZ_ASSERT(qreg >= 0 && qreg < num_q_registers);
memcpy(value, vfp_registers_ + qreg * 4, sizeof(*value) * 2);
}
void
Simulator::set_q_register(int qreg, const uint64_t* value)
{
MOZ_ASSERT(qreg >= 0 && qreg < num_q_registers);
memcpy(vfp_registers_ + qreg * 4, value, sizeof(*value) * 2);
}
void
Simulator::get_q_register(int qreg, uint32_t* value)
{
MOZ_ASSERT(qreg >= 0 && qreg < num_q_registers);
memcpy(value, vfp_registers_ + qreg * 4, sizeof(*value) * 4);
}
void
Simulator::set_q_register(int qreg, const uint32_t* value)
{
MOZ_ASSERT((qreg >= 0) && (qreg < num_q_registers));
memcpy(vfp_registers_ + qreg * 4, value, sizeof(*value) * 4);
}
void
Simulator::set_pc(int32_t value)
{
pc_modified_ = true;
registers_[pc] = value;
}
bool
Simulator::has_bad_pc() const
{
return registers_[pc] == bad_lr || registers_[pc] == end_sim_pc;
}
// Raw access to the PC register without the special adjustment when reading.
int32_t
Simulator::get_pc() const
{
return registers_[pc];
}
void
Simulator::set_s_register(int sreg, unsigned int value)
{
MOZ_ASSERT(sreg >= 0 && sreg < num_s_registers);
vfp_registers_[sreg] = value;
}
unsigned
Simulator::get_s_register(int sreg) const
{
MOZ_ASSERT(sreg >= 0 && sreg < num_s_registers);
return vfp_registers_[sreg];
}
template<class InputType, int register_size>
void
Simulator::setVFPRegister(int reg_index, const InputType& value)
{
MOZ_ASSERT(reg_index >= 0);
MOZ_ASSERT_IF(register_size == 1, reg_index < num_s_registers);
MOZ_ASSERT_IF(register_size == 2, reg_index < int(FloatRegisters::TotalPhys));
char buffer[register_size * sizeof(vfp_registers_[0])];
memcpy(buffer, &value, register_size * sizeof(vfp_registers_[0]));
memcpy(&vfp_registers_[reg_index * register_size], buffer,
register_size * sizeof(vfp_registers_[0]));
}
template<class ReturnType, int register_size>
ReturnType Simulator::getFromVFPRegister(int reg_index)
{
MOZ_ASSERT(reg_index >= 0);
MOZ_ASSERT_IF(register_size == 1, reg_index < num_s_registers);
MOZ_ASSERT_IF(register_size == 2, reg_index < int(FloatRegisters::TotalPhys));
ReturnType value = 0;
char buffer[register_size * sizeof(vfp_registers_[0])];
memcpy(buffer, &vfp_registers_[register_size * reg_index],
register_size * sizeof(vfp_registers_[0]));
memcpy(&value, buffer, register_size * sizeof(vfp_registers_[0]));
return value;
}
// These forced-instantiations are for jsapi-tests. Evidently, nothing
// requires these to be instantiated.
template double Simulator::getFromVFPRegister<double, 2>(int reg_index);
template float Simulator::getFromVFPRegister<float, 1>(int reg_index);
template void Simulator::setVFPRegister<double, 2>(int reg_index, const double& value);
template void Simulator::setVFPRegister<float, 1>(int reg_index, const float& value);
void
Simulator::getFpArgs(double* x, double* y, int32_t* z)
{
if (UseHardFpABI()) {
*x = get_double_from_d_register(0);
*y = get_double_from_d_register(1);
*z = get_register(0);
} else {
*x = get_double_from_register_pair(0);
*y = get_double_from_register_pair(2);
*z = get_register(2);
}
}
void
Simulator::getFpFromStack(int32_t* stack, double* x)
{
MOZ_ASSERT(stack && x);
char buffer[2 * sizeof(stack[0])];
memcpy(buffer, stack, 2 * sizeof(stack[0]));
memcpy(x, buffer, 2 * sizeof(stack[0]));
}
void
Simulator::setCallResultDouble(double result)
{
// The return value is either in r0/r1 or d0.
if (UseHardFpABI()) {
char buffer[2 * sizeof(vfp_registers_[0])];
memcpy(buffer, &result, sizeof(buffer));
// Copy result to d0.
memcpy(vfp_registers_, buffer, sizeof(buffer));
} else {
char buffer[2 * sizeof(registers_[0])];
memcpy(buffer, &result, sizeof(buffer));
// Copy result to r0 and r1.
memcpy(registers_, buffer, sizeof(buffer));
}
}
void
Simulator::setCallResultFloat(float result)
{
if (UseHardFpABI()) {
char buffer[sizeof(registers_[0])];
memcpy(buffer, &result, sizeof(buffer));
// Copy result to s0.
memcpy(vfp_registers_, buffer, sizeof(buffer));
} else {
char buffer[sizeof(registers_[0])];
memcpy(buffer, &result, sizeof(buffer));
// Copy result to r0.
memcpy(registers_, buffer, sizeof(buffer));
}
}
void
Simulator::setCallResult(int64_t res)
{
set_register(r0, static_cast<int32_t>(res));
set_register(r1, static_cast<int32_t>(res >> 32));
}
void
Simulator::exclusiveMonitorSet(uint64_t value)
{
exclusiveMonitor_ = value;
exclusiveMonitorHeld_ = true;
}
uint64_t
Simulator::exclusiveMonitorGetAndClear(bool* held)
{
*held = exclusiveMonitorHeld_;
exclusiveMonitorHeld_ = false;
return *held ? exclusiveMonitor_ : 0;
}
void
Simulator::exclusiveMonitorClear()
{
exclusiveMonitorHeld_ = false;
}
int
Simulator::readW(int32_t addr, SimInstruction* instr)
{
// The regexp engine emits unaligned loads, so we don't check for them here
// like most of the other methods do.
if ((addr & 3) == 0 || !HasAlignmentFault()) {
intptr_t* ptr = reinterpret_cast<intptr_t*>(addr);
return *ptr;
} else {
printf("Unaligned write at 0x%08x, pc=%p\n", addr, instr);
MOZ_CRASH();
}
}
void
Simulator::writeW(int32_t addr, int value, SimInstruction* instr)
{
if ((addr & 3) == 0) {
intptr_t* ptr = reinterpret_cast<intptr_t*>(addr);
*ptr = value;
} else {
printf("Unaligned write at 0x%08x, pc=%p\n", addr, instr);
MOZ_CRASH();
}
}
// For the time being, define Relaxed operations in terms of SeqCst
// operations - we don't yet need Relaxed operations anywhere else in
// the system, and the distinction is not important to the simulation
// at the level where we're operating.
template<typename T>
static
T loadRelaxed(SharedMem<T*> addr)
{
return AtomicOperations::loadSeqCst(addr);
}
template<typename T>
static
T compareExchangeRelaxed(SharedMem<T*> addr, T oldval, T newval)
{
return AtomicOperations::compareExchangeSeqCst(addr, oldval, newval);
}
int
Simulator::readExW(int32_t addr, SimInstruction* instr)
{
// The regexp engine emits unaligned loads, so we don't check for them here
// like most of the other methods do.
if ((addr & 3) == 0 || !HasAlignmentFault()) {
SharedMem<int32_t*> ptr = SharedMem<int32_t*>::shared(reinterpret_cast<int32_t*>(addr));
int32_t value = loadRelaxed(ptr);
exclusiveMonitorSet(value);
return value;
} else {
printf("Unaligned write at 0x%08x, pc=%p\n", addr, instr);
MOZ_CRASH();
}
}
int32_t
Simulator::writeExW(int32_t addr, int value, SimInstruction* instr)
{
if ((addr & 3) == 0) {
SharedMem<int32_t*> ptr = SharedMem<int32_t*>::shared(reinterpret_cast<int32_t*>(addr));
bool held;
int32_t expected = int32_t(exclusiveMonitorGetAndClear(&held));
if (!held)
return 1;
int32_t old = compareExchangeRelaxed(ptr, expected, int32_t(value));
return old != expected;
} else {
printf("Unaligned write at 0x%08x, pc=%p\n", addr, instr);
MOZ_CRASH();
}
}
uint16_t
Simulator::readHU(int32_t addr, SimInstruction* instr)
{
// The regexp engine emits unaligned loads, so we don't check for them here
// like most of the other methods do.
if ((addr & 1) == 0 || !HasAlignmentFault()) {
uint16_t* ptr = reinterpret_cast<uint16_t*>(addr);
return *ptr;
}
printf("Unaligned unsigned halfword read at 0x%08x, pc=%p\n", addr, instr);
MOZ_CRASH();
return 0;
}
int16_t
Simulator::readH(int32_t addr, SimInstruction* instr)
{
if ((addr & 1) == 0) {
int16_t* ptr = reinterpret_cast<int16_t*>(addr);
return *ptr;
}
printf("Unaligned signed halfword read at 0x%08x\n", addr);
MOZ_CRASH();
return 0;
}
void
Simulator::writeH(int32_t addr, uint16_t value, SimInstruction* instr)
{
if ((addr & 1) == 0) {
uint16_t* ptr = reinterpret_cast<uint16_t*>(addr);
*ptr = value;
} else {
printf("Unaligned unsigned halfword write at 0x%08x, pc=%p\n", addr, instr);
MOZ_CRASH();
}
}
void
Simulator::writeH(int32_t addr, int16_t value, SimInstruction* instr)
{
if ((addr & 1) == 0) {
int16_t* ptr = reinterpret_cast<int16_t*>(addr);
*ptr = value;
} else {
printf("Unaligned halfword write at 0x%08x, pc=%p\n", addr, instr);
MOZ_CRASH();
}
}
uint16_t
Simulator::readExHU(int32_t addr, SimInstruction* instr)
{
// The regexp engine emits unaligned loads, so we don't check for them here
// like most of the other methods do.
if ((addr & 1) == 0 || !HasAlignmentFault()) {
SharedMem<uint16_t*> ptr = SharedMem<uint16_t*>::shared(reinterpret_cast<uint16_t*>(addr));
uint16_t value = loadRelaxed(ptr);
exclusiveMonitorSet(value);
return value;
}
printf("Unaligned atomic unsigned halfword read at 0x%08x, pc=%p\n", addr, instr);
MOZ_CRASH();
return 0;
}
int32_t
Simulator::writeExH(int32_t addr, uint16_t value, SimInstruction* instr)
{
if ((addr & 1) == 0) {
SharedMem<uint16_t*> ptr = SharedMem<uint16_t*>::shared(reinterpret_cast<uint16_t*>(addr));
bool held;
uint16_t expected = uint16_t(exclusiveMonitorGetAndClear(&held));
if (!held)
return 1;
uint16_t old = compareExchangeRelaxed(ptr, expected, value);
return old != expected;
} else {
printf("Unaligned atomic unsigned halfword write at 0x%08x, pc=%p\n", addr, instr);
MOZ_CRASH();
}
}
uint8_t
Simulator::readBU(int32_t addr)
{
uint8_t* ptr = reinterpret_cast<uint8_t*>(addr);
return *ptr;
}
uint8_t
Simulator::readExBU(int32_t addr)
{
SharedMem<uint8_t*> ptr = SharedMem<uint8_t*>::shared(reinterpret_cast<uint8_t*>(addr));
uint8_t value = loadRelaxed(ptr);
exclusiveMonitorSet(value);
return value;
}
int32_t
Simulator::writeExB(int32_t addr, uint8_t value)
{
SharedMem<uint8_t*> ptr = SharedMem<uint8_t*>::shared(reinterpret_cast<uint8_t*>(addr));
bool held;
uint8_t expected = uint8_t(exclusiveMonitorGetAndClear(&held));
if (!held)
return 1;
uint8_t old = compareExchangeRelaxed(ptr, expected, value);
return old != expected;
}
int8_t
Simulator::readB(int32_t addr)
{
int8_t* ptr = reinterpret_cast<int8_t*>(addr);
return *ptr;
}
void
Simulator::writeB(int32_t addr, uint8_t value)
{
uint8_t* ptr = reinterpret_cast<uint8_t*>(addr);
*ptr = value;
}
void
Simulator::writeB(int32_t addr, int8_t value)
{
int8_t* ptr = reinterpret_cast<int8_t*>(addr);
*ptr = value;
}
int32_t*
Simulator::readDW(int32_t addr)
{
if ((addr & 3) == 0) {
int32_t* ptr = reinterpret_cast<int32_t*>(addr);
return ptr;
}
printf("Unaligned read at 0x%08x\n", addr);
MOZ_CRASH();
return 0;
}
void
Simulator::writeDW(int32_t addr, int32_t value1, int32_t value2)
{
if ((addr & 3) == 0) {
int32_t* ptr = reinterpret_cast<int32_t*>(addr);
*ptr++ = value1;
*ptr = value2;
} else {
printf("Unaligned write at 0x%08x\n", addr);
MOZ_CRASH();
}
}
int32_t
Simulator::readExDW(int32_t addr, int32_t* hibits)
{
#if defined(__clang__) && defined(__i386)
// This is OK for now, we don't yet generate LDREXD.
MOZ_CRASH("Unimplemented - 8-byte atomics are unsupported in Clang on i386");
#else
if ((addr & 3) == 0) {
SharedMem<uint64_t*> ptr = SharedMem<uint64_t*>::shared(reinterpret_cast<uint64_t*>(addr));
uint64_t value = loadRelaxed(ptr);
exclusiveMonitorSet(value);
*hibits = int32_t(value);
return int32_t(value >> 32);
}
printf("Unaligned read at 0x%08x\n", addr);
MOZ_CRASH();
return 0;
#endif
}
int32_t
Simulator::writeExDW(int32_t addr, int32_t value1, int32_t value2)
{
#if defined(__clang__) && defined(__i386)
// This is OK for now, we don't yet generate STREXD.
MOZ_CRASH("Unimplemented - 8-byte atomics are unsupported in Clang on i386");
#else
if ((addr & 3) == 0) {
SharedMem<uint64_t*> ptr = SharedMem<uint64_t*>::shared(reinterpret_cast<uint64_t*>(addr));
uint64_t value = (uint64_t(value1) << 32) | uint32_t(value2);
bool held;
uint64_t expected = exclusiveMonitorGetAndClear(&held);
if (!held)
return 1;
uint64_t old = compareExchangeRelaxed(ptr, expected, value);
return old != expected;
} else {
printf("Unaligned write at 0x%08x\n", addr);
MOZ_CRASH();
}
#endif
}
uintptr_t
Simulator::stackLimit() const
{
return stackLimit_;
}
uintptr_t*
Simulator::addressOfStackLimit()
{
return &stackLimit_;
}
bool
Simulator::overRecursed(uintptr_t newsp) const
{
if (newsp == 0)
newsp = get_register(sp);
return newsp <= stackLimit();
}
bool
Simulator::overRecursedWithExtra(uint32_t extra) const
{
uintptr_t newsp = get_register(sp) - extra;
return newsp <= stackLimit();
}
// Checks if the current instruction should be executed based on its condition
// bits.
bool
Simulator::conditionallyExecute(SimInstruction* instr)
{
switch (instr->conditionField()) {
case Assembler::EQ: return z_flag_;
case Assembler::NE: return !z_flag_;
case Assembler::CS: return c_flag_;
case Assembler::CC: return !c_flag_;
case Assembler::MI: return n_flag_;
case Assembler::PL: return !n_flag_;
case Assembler::VS: return v_flag_;
case Assembler::VC: return !v_flag_;
case Assembler::HI: return c_flag_ && !z_flag_;
case Assembler::LS: return !c_flag_ || z_flag_;
case Assembler::GE: return n_flag_ == v_flag_;
case Assembler::LT: return n_flag_ != v_flag_;
case Assembler::GT: return !z_flag_ && (n_flag_ == v_flag_);
case Assembler::LE: return z_flag_ || (n_flag_ != v_flag_);
case Assembler::AL: return true;
default: MOZ_CRASH();
}
return false;
}
// Calculate and set the Negative and Zero flags.
void
Simulator::setNZFlags(int32_t val)
{
n_flag_ = (val < 0);
z_flag_ = (val == 0);
}
// Set the Carry flag.
void
Simulator::setCFlag(bool val)
{
c_flag_ = val;
}
// Set the oVerflow flag.
void
Simulator::setVFlag(bool val)
{
v_flag_ = val;
}
// Calculate C flag value for additions.
bool
Simulator::carryFrom(int32_t left, int32_t right, int32_t carry)
{
uint32_t uleft = static_cast<uint32_t>(left);
uint32_t uright = static_cast<uint32_t>(right);
uint32_t urest = 0xffffffffU - uleft;
return (uright > urest) ||
(carry && (((uright + 1) > urest) || (uright > (urest - 1))));
}
// Calculate C flag value for subtractions.
bool
Simulator::borrowFrom(int32_t left, int32_t right)
{
uint32_t uleft = static_cast<uint32_t>(left);
uint32_t uright = static_cast<uint32_t>(right);
return (uright > uleft);
}
// Calculate V flag value for additions and subtractions.
bool
Simulator::overflowFrom(int32_t alu_out, int32_t left, int32_t right, bool addition)
{
bool overflow;
if (addition) {
// Operands have the same sign.
overflow = ((left >= 0 && right >= 0) || (left < 0 && right < 0))
// And operands and result have different sign.
&& ((left < 0 && alu_out >= 0) || (left >= 0 && alu_out < 0));
} else {
// Operands have different signs.
overflow = ((left < 0 && right >= 0) || (left >= 0 && right < 0))
// And first operand and result have different signs.
&& ((left < 0 && alu_out >= 0) || (left >= 0 && alu_out < 0));
}
return overflow;
}
// Support for VFP comparisons.
void
Simulator::compute_FPSCR_Flags(double val1, double val2)
{
if (mozilla::IsNaN(val1) || mozilla::IsNaN(val2)) {
n_flag_FPSCR_ = false;
z_flag_FPSCR_ = false;
c_flag_FPSCR_ = true;
v_flag_FPSCR_ = true;
// All non-NaN cases.
} else if (val1 == val2) {
n_flag_FPSCR_ = false;
z_flag_FPSCR_ = true;
c_flag_FPSCR_ = true;
v_flag_FPSCR_ = false;
} else if (val1 < val2) {
n_flag_FPSCR_ = true;
z_flag_FPSCR_ = false;
c_flag_FPSCR_ = false;
v_flag_FPSCR_ = false;
} else {
// Case when (val1 > val2).
n_flag_FPSCR_ = false;
z_flag_FPSCR_ = false;
c_flag_FPSCR_ = true;
v_flag_FPSCR_ = false;
}
}
void
Simulator::copy_FPSCR_to_APSR()
{
n_flag_ = n_flag_FPSCR_;
z_flag_ = z_flag_FPSCR_;
c_flag_ = c_flag_FPSCR_;
v_flag_ = v_flag_FPSCR_;
}
// Addressing Mode 1 - Data-processing operands:
// Get the value based on the shifter_operand with register.
int32_t
Simulator::getShiftRm(SimInstruction* instr, bool* carry_out)
{
ShiftType shift = instr->shifttypeValue();
int shift_amount = instr->shiftAmountValue();
int32_t result = get_register(instr->rmValue());
if (instr->bit(4) == 0) {
// By immediate.
if (shift == ROR && shift_amount == 0) {
MOZ_CRASH("NYI");
return result;
}
if ((shift == LSR || shift == ASR) && shift_amount == 0)
shift_amount = 32;
switch (shift) {
case ASR: {
if (shift_amount == 0) {
if (result < 0) {
result = 0xffffffff;
*carry_out = true;
} else {
result = 0;
*carry_out = false;
}
} else {
result >>= (shift_amount - 1);
*carry_out = (result & 1) == 1;
result >>= 1;
}
break;
}
case LSL: {
if (shift_amount == 0) {
*carry_out = c_flag_;
} else {
result <<= (shift_amount - 1);
*carry_out = (result < 0);
result <<= 1;
}
break;
}
case LSR: {
if (shift_amount == 0) {
result = 0;
*carry_out = c_flag_;
} else {
uint32_t uresult = static_cast<uint32_t>(result);
uresult >>= (shift_amount - 1);
*carry_out = (uresult & 1) == 1;
uresult >>= 1;
result = static_cast<int32_t>(uresult);
}
break;
}
case ROR: {
if (shift_amount == 0) {
*carry_out = c_flag_;
} else {
uint32_t left = static_cast<uint32_t>(result) >> shift_amount;
uint32_t right = static_cast<uint32_t>(result) << (32 - shift_amount);
result = right | left;
*carry_out = (static_cast<uint32_t>(result) >> 31) != 0;
}
break;
}
default:
MOZ_CRASH();
}
} else {
// By register.
int rs = instr->rsValue();
shift_amount = get_register(rs) &0xff;
switch (shift) {
case ASR: {
if (shift_amount == 0) {
*carry_out = c_flag_;
} else if (shift_amount < 32) {
result >>= (shift_amount - 1);
*carry_out = (result & 1) == 1;
result >>= 1;
} else {
MOZ_ASSERT(shift_amount >= 32);
if (result < 0) {
*carry_out = true;
result = 0xffffffff;
} else {
*carry_out = false;
result = 0;
}
}
break;
}
case LSL: {
if (shift_amount == 0) {
*carry_out = c_flag_;
} else if (shift_amount < 32) {
result <<= (shift_amount - 1);
*carry_out = (result < 0);
result <<= 1;
} else if (shift_amount == 32) {
*carry_out = (result & 1) == 1;
result = 0;
} else {
MOZ_ASSERT(shift_amount > 32);
*carry_out = false;
result = 0;
}
break;
}
case LSR: {
if (shift_amount == 0) {
*carry_out = c_flag_;
} else if (shift_amount < 32) {
uint32_t uresult = static_cast<uint32_t>(result);
uresult >>= (shift_amount - 1);
*carry_out = (uresult & 1) == 1;
uresult >>= 1;
result = static_cast<int32_t>(uresult);
} else if (shift_amount == 32) {
*carry_out = (result < 0);
result = 0;
} else {
*carry_out = false;
result = 0;
}
break;
}
case ROR: {
if (shift_amount == 0) {
*carry_out = c_flag_;
} else {
uint32_t left = static_cast<uint32_t>(result) >> shift_amount;
uint32_t right = static_cast<uint32_t>(result) << (32 - shift_amount);
result = right | left;
*carry_out = (static_cast<uint32_t>(result) >> 31) != 0;
}
break;
}
default:
MOZ_CRASH();
}
}
return result;
}
// Addressing Mode 1 - Data-processing operands:
// Get the value based on the shifter_operand with immediate.
int32_t
Simulator::getImm(SimInstruction* instr, bool* carry_out)
{
int rotate = instr->rotateValue() * 2;
int immed8 = instr->immed8Value();
int imm = (immed8 >> rotate) | (immed8 << (32 - rotate));
*carry_out = (rotate == 0) ? c_flag_ : (imm < 0);
return imm;
}
int32_t
Simulator::processPU(SimInstruction* instr, int num_regs, int reg_size,
intptr_t* start_address, intptr_t* end_address)
{
int rn = instr->rnValue();
int32_t rn_val = get_register(rn);
switch (instr->PUField()) {
case da_x:
MOZ_CRASH();
break;
case ia_x:
*start_address = rn_val;
*end_address = rn_val + (num_regs * reg_size) - reg_size;
rn_val = rn_val + (num_regs * reg_size);
break;
case db_x:
*start_address = rn_val - (num_regs * reg_size);
*end_address = rn_val - reg_size;
rn_val = *start_address;
break;
case ib_x:
*start_address = rn_val + reg_size;
*end_address = rn_val + (num_regs * reg_size);
rn_val = *end_address;
break;
default:
MOZ_CRASH();
}
return rn_val;
}
// Addressing Mode 4 - Load and Store Multiple
void
Simulator::handleRList(SimInstruction* instr, bool load)
{
int rlist = instr->rlistValue();
int num_regs = mozilla::CountPopulation32(rlist);
intptr_t start_address = 0;
intptr_t end_address = 0;
int32_t rn_val = processPU(instr, num_regs, sizeof(void*), &start_address, &end_address);
intptr_t* address = reinterpret_cast<intptr_t*>(start_address);
// Catch null pointers a little earlier.
MOZ_ASSERT(start_address > 8191 || start_address < 0);
int reg = 0;
while (rlist != 0) {
if ((rlist & 1) != 0) {
if (load) {
set_register(reg, *address);
} else {
*address = get_register(reg);
}
address += 1;
}
reg++;
rlist >>= 1;
}
MOZ_ASSERT(end_address == ((intptr_t)address) - 4);
if (instr->hasW())
set_register(instr->rnValue(), rn_val);
}
// Addressing Mode 6 - Load and Store Multiple Coprocessor registers.
void
Simulator::handleVList(SimInstruction* instr)
{
VFPRegPrecision precision = (instr->szValue() == 0) ? kSinglePrecision : kDoublePrecision;
int operand_size = (precision == kSinglePrecision) ? 4 : 8;
bool load = (instr->VLValue() == 0x1);
int vd;
int num_regs;
vd = instr->VFPDRegValue(precision);
if (precision == kSinglePrecision)
num_regs = instr->immed8Value();
else
num_regs = instr->immed8Value() / 2;
intptr_t start_address = 0;
intptr_t end_address = 0;
int32_t rn_val = processPU(instr, num_regs, operand_size, &start_address, &end_address);
intptr_t* address = reinterpret_cast<intptr_t*>(start_address);
for (int reg = vd; reg < vd + num_regs; reg++) {
if (precision == kSinglePrecision) {
if (load)
set_s_register_from_sinteger(reg, readW(reinterpret_cast<int32_t>(address), instr));
else
writeW(reinterpret_cast<int32_t>(address), get_sinteger_from_s_register(reg), instr);
address += 1;
} else {
if (load) {
int32_t data[] = {
readW(reinterpret_cast<int32_t>(address), instr),
readW(reinterpret_cast<int32_t>(address + 1), instr)
};
double d;
memcpy(&d, data, 8);
set_d_register_from_double(reg, d);
} else {
int32_t data[2];
double d = get_double_from_d_register(reg);
memcpy(data, &d, 8);
writeW(reinterpret_cast<int32_t>(address), data[0], instr);
writeW(reinterpret_cast<int32_t>(address + 1), data[1], instr);
}
address += 2;
}
}
MOZ_ASSERT(reinterpret_cast<intptr_t>(address) - operand_size == end_address);
if (instr->hasW())
set_register(instr->rnValue(), rn_val);
}
// Note: With the code below we assume that all runtime calls return a 64 bits
// result. If they don't, the r1 result register contains a bogus value, which
// is fine because it is caller-saved.
typedef int64_t (*Prototype_General0)();
typedef int64_t (*Prototype_General1)(int32_t arg0);
typedef int64_t (*Prototype_General2)(int32_t arg0, int32_t arg1);
typedef int64_t (*Prototype_General3)(int32_t arg0, int32_t arg1, int32_t arg2);
typedef int64_t (*Prototype_General4)(int32_t arg0, int32_t arg1, int32_t arg2, int32_t arg3);
typedef int64_t (*Prototype_General5)(int32_t arg0, int32_t arg1, int32_t arg2, int32_t arg3,
int32_t arg4);
typedef int64_t (*Prototype_General6)(int32_t arg0, int32_t arg1, int32_t arg2, int32_t arg3,
int32_t arg4, int32_t arg5);
typedef int64_t (*Prototype_General7)(int32_t arg0, int32_t arg1, int32_t arg2, int32_t arg3,
int32_t arg4, int32_t arg5, int32_t arg6);
typedef int64_t (*Prototype_General8)(int32_t arg0, int32_t arg1, int32_t arg2, int32_t arg3,
int32_t arg4, int32_t arg5, int32_t arg6, int32_t arg7);
typedef double (*Prototype_Double_None)();
typedef double (*Prototype_Double_Double)(double arg0);
typedef double (*Prototype_Double_Int)(int32_t arg0);
typedef int32_t (*Prototype_Int_Double)(double arg0);
typedef int32_t (*Prototype_Int_DoubleIntInt)(double arg0, int32_t arg1, int32_t arg2);
typedef int32_t (*Prototype_Int_IntDoubleIntInt)(int32_t arg0, double arg1, int32_t arg2,
int32_t arg3);
typedef float (*Prototype_Float32_Float32)(float arg0);
typedef double (*Prototype_DoubleInt)(double arg0, int32_t arg1);
typedef double (*Prototype_Double_IntDouble)(int32_t arg0, double arg1);
typedef double (*Prototype_Double_DoubleDouble)(double arg0, double arg1);
typedef int32_t (*Prototype_Int_IntDouble)(int32_t arg0, double arg1);
typedef double (*Prototype_Double_DoubleDoubleDouble)(double arg0, double arg1, double arg2);
typedef double (*Prototype_Double_DoubleDoubleDoubleDouble)(double arg0, double arg1,
double arg2, double arg3);
// Fill the volatile registers with scratch values.
//
// Some of the ABI calls assume that the float registers are not scratched, even
// though the ABI defines them as volatile - a performance optimization. These
// are all calls passing operands in integer registers, so for now the simulator
// does not scratch any float registers for these calls. Should try to narrow it
// further in future.
//
void
Simulator::scratchVolatileRegisters(bool scratchFloat)
{
int32_t scratch_value = 0xa5a5a5a5 ^ uint32_t(icount_);
set_register(r0, scratch_value);
set_register(r1, scratch_value);
set_register(r2, scratch_value);
set_register(r3, scratch_value);
set_register(r12, scratch_value); // Intra-Procedure-call scratch register.
set_register(r14, scratch_value); // Link register.
if (scratchFloat) {
uint64_t scratch_value_d = 0x5a5a5a5a5a5a5a5aLU ^ uint64_t(icount_) ^ (uint64_t(icount_) << 30);
for (uint32_t i = d0; i < d8; i++)
set_d_register(i, &scratch_value_d);
for (uint32_t i = d16; i < FloatRegisters::TotalPhys; i++)
set_d_register(i, &scratch_value_d);
}
}
// Software interrupt instructions are used by the simulator to call into C++.
void
Simulator::softwareInterrupt(SimInstruction* instr)
{
int svc = instr->svcValue();
switch (svc) {
case kCallRtRedirected: {
Redirection* redirection = Redirection::FromSwiInstruction(instr);
int32_t arg0 = get_register(r0);
int32_t arg1 = get_register(r1);
int32_t arg2 = get_register(r2);
int32_t arg3 = get_register(r3);
int32_t* stack_pointer = reinterpret_cast<int32_t*>(get_register(sp));
int32_t arg4 = stack_pointer[0];
int32_t arg5 = stack_pointer[1];
int32_t saved_lr = get_register(lr);
intptr_t external = reinterpret_cast<intptr_t>(redirection->nativeFunction());
bool stack_aligned = (get_register(sp) & (ABIStackAlignment - 1)) == 0;
if (!stack_aligned) {
fprintf(stderr, "Runtime call with unaligned stack!\n");
MOZ_CRASH();
}
if (single_stepping_)
single_step_callback_(single_step_callback_arg_, this, nullptr);
switch (redirection->type()) {
case Args_General0: {
Prototype_General0 target = reinterpret_cast<Prototype_General0>(external);
int64_t result = target();
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResult(result);
break;
}
case Args_General1: {
Prototype_General1 target = reinterpret_cast<Prototype_General1>(external);
int64_t result = target(arg0);
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResult(result);
break;
}
case Args_General2: {
Prototype_General2 target = reinterpret_cast<Prototype_General2>(external);
int64_t result = target(arg0, arg1);
// The ARM backend makes calls to __aeabi_idivmod and
// __aeabi_uidivmod assuming that the float registers are
// non-volatile as a performance optimization, so the float
// registers must not be scratch when calling these.
bool scratchFloat = target != __aeabi_idivmod && target != __aeabi_uidivmod;
scratchVolatileRegisters(/* scratchFloat = */ scratchFloat);
setCallResult(result);
break;
}
case Args_General3: {
Prototype_General3 target = reinterpret_cast<Prototype_General3>(external);
int64_t result = target(arg0, arg1, arg2);
scratchVolatileRegisters(/* scratchFloat = true*/);
setCallResult(result);
break;
}
case Args_General4: {
Prototype_General4 target = reinterpret_cast<Prototype_General4>(external);
int64_t result = target(arg0, arg1, arg2, arg3);
scratchVolatileRegisters(/* scratchFloat = true*/);
setCallResult(result);
break;
}
case Args_General5: {
Prototype_General5 target = reinterpret_cast<Prototype_General5>(external);
int64_t result = target(arg0, arg1, arg2, arg3, arg4);
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResult(result);
break;
}
case Args_General6: {
Prototype_General6 target = reinterpret_cast<Prototype_General6>(external);
int64_t result = target(arg0, arg1, arg2, arg3, arg4, arg5);
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResult(result);
break;
}
case Args_General7: {
Prototype_General7 target = reinterpret_cast<Prototype_General7>(external);
int32_t arg6 = stack_pointer[2];
int64_t result = target(arg0, arg1, arg2, arg3, arg4, arg5, arg6);
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResult(result);
break;
}
case Args_General8: {
Prototype_General8 target = reinterpret_cast<Prototype_General8>(external);
int32_t arg6 = stack_pointer[2];
int32_t arg7 = stack_pointer[3];
int64_t result = target(arg0, arg1, arg2, arg3, arg4, arg5, arg6, arg7);
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResult(result);
break;
}
case Args_Double_None: {
Prototype_Double_None target = reinterpret_cast<Prototype_Double_None>(external);
double dresult = target();
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResultDouble(dresult);
break;
}
case Args_Int_Double: {
double dval0, dval1;
int32_t ival;
getFpArgs(&dval0, &dval1, &ival);
Prototype_Int_Double target = reinterpret_cast<Prototype_Int_Double>(external);
int32_t res = target(dval0);
scratchVolatileRegisters(/* scratchFloat = true */);
set_register(r0, res);
break;
}
case Args_Double_Double: {
double dval0, dval1;
int32_t ival;
getFpArgs(&dval0, &dval1, &ival);
Prototype_Double_Double target = reinterpret_cast<Prototype_Double_Double>(external);
double dresult = target(dval0);
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResultDouble(dresult);
break;
}
case Args_Float32_Float32: {
float fval0;
if (UseHardFpABI())
fval0 = get_float_from_s_register(0);
else
fval0 = mozilla::BitwiseCast<float>(arg0);
Prototype_Float32_Float32 target = reinterpret_cast<Prototype_Float32_Float32>(external);
float fresult = target(fval0);
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResultFloat(fresult);
break;
}
case Args_Double_Int: {
Prototype_Double_Int target = reinterpret_cast<Prototype_Double_Int>(external);
double dresult = target(arg0);
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResultDouble(dresult);
break;
}
case Args_Double_DoubleInt: {
double dval0, dval1;
int32_t ival;
getFpArgs(&dval0, &dval1, &ival);
Prototype_DoubleInt target = reinterpret_cast<Prototype_DoubleInt>(external);
double dresult = target(dval0, ival);
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResultDouble(dresult);
break;
}
case Args_Double_DoubleDouble: {
double dval0, dval1;
int32_t ival;
getFpArgs(&dval0, &dval1, &ival);
Prototype_Double_DoubleDouble target = reinterpret_cast<Prototype_Double_DoubleDouble>(external);
double dresult = target(dval0, dval1);
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResultDouble(dresult);
break;
}
case Args_Double_IntDouble: {
int32_t ival = get_register(0);
double dval0;
if (UseHardFpABI())
dval0 = get_double_from_d_register(0);
else
dval0 = get_double_from_register_pair(2);
Prototype_Double_IntDouble target = reinterpret_cast<Prototype_Double_IntDouble>(external);
double dresult = target(ival, dval0);
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResultDouble(dresult);
break;
}
case Args_Int_IntDouble: {
int32_t ival = get_register(0);
double dval0;
if (UseHardFpABI())
dval0 = get_double_from_d_register(0);
else
dval0 = get_double_from_register_pair(2);
Prototype_Int_IntDouble target = reinterpret_cast<Prototype_Int_IntDouble>(external);
int32_t result = target(ival, dval0);
scratchVolatileRegisters(/* scratchFloat = true */);
set_register(r0, result);
break;
}
case Args_Int_DoubleIntInt: {
double dval;
int32_t result;
Prototype_Int_DoubleIntInt target = reinterpret_cast<Prototype_Int_DoubleIntInt>(external);
if (UseHardFpABI()) {
dval = get_double_from_d_register(0);
result = target(dval, arg0, arg1);
} else {
dval = get_double_from_register_pair(0);
result = target(dval, arg2, arg3);
}
scratchVolatileRegisters(/* scratchFloat = true */);
set_register(r0, result);
break;
}
case Args_Int_IntDoubleIntInt: {
double dval;
int32_t result;
Prototype_Int_IntDoubleIntInt target = reinterpret_cast<Prototype_Int_IntDoubleIntInt>(external);
if (UseHardFpABI()) {
dval = get_double_from_d_register(0);
result = target(arg0, dval, arg1, arg2);
} else {
dval = get_double_from_register_pair(2);
result = target(arg0, dval, arg4, arg5);
}
scratchVolatileRegisters(/* scratchFloat = true */);
set_register(r0, result);
break;
}
case Args_Double_DoubleDoubleDouble: {
double dval0, dval1, dval2;
int32_t ival;
getFpArgs(&dval0, &dval1, &ival);
// the last argument is on stack
getFpFromStack(stack_pointer, &dval2);
Prototype_Double_DoubleDoubleDouble target = reinterpret_cast<Prototype_Double_DoubleDoubleDouble>(external);
double dresult = target(dval0, dval1, dval2);
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResultDouble(dresult);
break;
}
case Args_Double_DoubleDoubleDoubleDouble: {
double dval0, dval1, dval2, dval3;
int32_t ival;
getFpArgs(&dval0, &dval1, &ival);
// the two last arguments are on stack
getFpFromStack(stack_pointer, &dval2);
getFpFromStack(stack_pointer + 2, &dval3);
Prototype_Double_DoubleDoubleDoubleDouble target = reinterpret_cast<Prototype_Double_DoubleDoubleDoubleDouble>(external);
double dresult = target(dval0, dval1, dval2, dval3);
scratchVolatileRegisters(/* scratchFloat = true */);
setCallResultDouble(dresult);
break;
}
default:
MOZ_CRASH("call");
}
if (single_stepping_)
single_step_callback_(single_step_callback_arg_, this, nullptr);
set_register(lr, saved_lr);
set_pc(get_register(lr));
break;
}
case kBreakpoint: {
ArmDebugger dbg(this);
dbg.debug();
break;
}
default: { // Stop uses all codes greater than 1 << 23.
if (svc >= (1 << 23)) {
uint32_t code = svc & kStopCodeMask;
if (isWatchedStop(code))
increaseStopCounter(code);
// Stop if it is enabled, otherwise go on jumping over the stop and
// the message address.
if (isEnabledStop(code)) {
ArmDebugger dbg(this);
dbg.stop(instr);
} else {
set_pc(get_pc() + 2 * SimInstruction::kInstrSize);
}
} else {
// This is not a valid svc code.
MOZ_CRASH();
break;
}
}
}
}
double
Simulator::canonicalizeNaN(double value)
{
return FPSCR_default_NaN_mode_ ? JS::CanonicalizeNaN(value) : value;
}
// Stop helper functions.
bool
Simulator::isStopInstruction(SimInstruction* instr)
{
return (instr->bits(27, 24) == 0xF) && (instr->svcValue() >= kStopCode);
}
bool Simulator::isWatchedStop(uint32_t code)
{
MOZ_ASSERT(code <= kMaxStopCode);
return code < kNumOfWatchedStops;
}
bool
Simulator::isEnabledStop(uint32_t code)
{
MOZ_ASSERT(code <= kMaxStopCode);
// Unwatched stops are always enabled.
return !isWatchedStop(code) || !(watched_stops_[code].count & kStopDisabledBit);
}
void
Simulator::enableStop(uint32_t code)
{
MOZ_ASSERT(isWatchedStop(code));
if (!isEnabledStop(code))
watched_stops_[code].count &= ~kStopDisabledBit;
}
void
Simulator::disableStop(uint32_t code)
{
MOZ_ASSERT(isWatchedStop(code));
if (isEnabledStop(code))
watched_stops_[code].count |= kStopDisabledBit;
}
void
Simulator::increaseStopCounter(uint32_t code)
{
MOZ_ASSERT(code <= kMaxStopCode);
MOZ_ASSERT(isWatchedStop(code));
if ((watched_stops_[code].count & ~(1 << 31)) == 0x7fffffff) {
printf("Stop counter for code %i has overflowed.\n"
"Enabling this code and reseting the counter to 0.\n", code);
watched_stops_[code].count = 0;
enableStop(code);
} else {
watched_stops_[code].count++;
}
}
// Print a stop status.
void
Simulator::printStopInfo(uint32_t code)
{
MOZ_ASSERT(code <= kMaxStopCode);
if (!isWatchedStop(code)) {
printf("Stop not watched.");
} else {
const char* state = isEnabledStop(code) ? "Enabled" : "Disabled";
int32_t count = watched_stops_[code].count & ~kStopDisabledBit;
// Don't print the state of unused breakpoints.
if (count != 0) {
if (watched_stops_[code].desc) {
printf("stop %i - 0x%x: \t%s, \tcounter = %i, \t%s\n",
code, code, state, count, watched_stops_[code].desc);
} else {
printf("stop %i - 0x%x: \t%s, \tcounter = %i\n",
code, code, state, count);
}
}
}
}
// Instruction types 0 and 1 are both rolled into one function because they only
// differ in the handling of the shifter_operand.
void
Simulator::decodeType01(SimInstruction* instr)
{
int type = instr->typeValue();
if (type == 0 && instr->isSpecialType0()) {
// Multiply instruction or extra loads and stores.
if (instr->bits(7, 4) == 9) {
if (instr->bit(24) == 0) {
// Raw field decoding here. Multiply instructions have their Rd
// in funny places.
int rn = instr->rnValue();
int rm = instr->rmValue();
int rs = instr->rsValue();
int32_t rs_val = get_register(rs);
int32_t rm_val = get_register(rm);
if (instr->bit(23) == 0) {
if (instr->bit(21) == 0) {
// The MUL instruction description (A 4.1.33) refers to
// Rd as being the destination for the operation, but it
// confusingly uses the Rn field to encode it.
int rd = rn; // Remap the rn field to the Rd register.
int32_t alu_out = rm_val * rs_val;
set_register(rd, alu_out);
if (instr->hasS())
setNZFlags(alu_out);
} else {
int rd = instr->rdValue();
int32_t acc_value = get_register(rd);
if (instr->bit(22) == 0) {
// The MLA instruction description (A 4.1.28) refers
// to the order of registers as "Rd, Rm, Rs,
// Rn". But confusingly it uses the Rn field to
// encode the Rd register and the Rd field to encode
// the Rn register.
int32_t mul_out = rm_val * rs_val;
int32_t result = acc_value + mul_out;
set_register(rn, result);
} else {
int32_t mul_out = rm_val * rs_val;
int32_t result = acc_value - mul_out;
set_register(rn, result);
}
}
} else {
// The signed/long multiply instructions use the terms RdHi
// and RdLo when referring to the target registers. They are
// mapped to the Rn and Rd fields as follows:
// RdLo == Rd
// RdHi == Rn (This is confusingly stored in variable rd here
// because the mul instruction from above uses the
// Rn field to encode the Rd register. Good luck figuring
// this out without reading the ARM instruction manual
// at a very detailed level.)
int rd_hi = rn; // Remap the rn field to the RdHi register.
int rd_lo = instr->rdValue();
int32_t hi_res = 0;
int32_t lo_res = 0;
if (instr->bit(22) == 1) {
int64_t left_op = static_cast<int32_t>(rm_val);
int64_t right_op = static_cast<int32_t>(rs_val);
uint64_t result = left_op * right_op;
hi_res = static_cast<int32_t>(result >> 32);
lo_res = static_cast<int32_t>(result & 0xffffffff);
} else {
// Unsigned multiply.
uint64_t left_op = static_cast<uint32_t>(rm_val);
uint64_t right_op = static_cast<uint32_t>(rs_val);
uint64_t result = left_op * right_op;
hi_res = static_cast<int32_t>(result >> 32);
lo_res = static_cast<int32_t>(result & 0xffffffff);
}
set_register(rd_lo, lo_res);
set_register(rd_hi, hi_res);
if (instr->hasS())
MOZ_CRASH();
}
} else {
if (instr->bits(disasm::ExclusiveOpHi, disasm::ExclusiveOpLo) == disasm::ExclusiveOpcode) {
// Load-exclusive / store-exclusive.
if (instr->bit(disasm::ExclusiveLoad))