1 // Copyright 2015 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.
4 
5 #include "src/interpreter/bytecodes.h"
6 
7 #include "src/frames.h"
8 #include "src/interpreter/bytecode-traits.h"
9 
10 namespace v8 {
11 namespace internal {
12 namespace interpreter {
13 
14 
15 // static
ToString(Bytecode bytecode)16 const char* Bytecodes::ToString(Bytecode bytecode) {
17   switch (bytecode) {
18 #define CASE(Name, ...)   \
19   case Bytecode::k##Name: \
20     return #Name;
21     BYTECODE_LIST(CASE)
22 #undef CASE
23   }
24   UNREACHABLE();
25   return "";
26 }
27 
28 
29 // static
OperandTypeToString(OperandType operand_type)30 const char* Bytecodes::OperandTypeToString(OperandType operand_type) {
31   switch (operand_type) {
32 #define CASE(Name, _)        \
33   case OperandType::k##Name: \
34     return #Name;
35     OPERAND_TYPE_LIST(CASE)
36 #undef CASE
37   }
38   UNREACHABLE();
39   return "";
40 }
41 
42 
43 // static
OperandSizeToString(OperandSize operand_size)44 const char* Bytecodes::OperandSizeToString(OperandSize operand_size) {
45   switch (operand_size) {
46     case OperandSize::kNone:
47       return "None";
48     case OperandSize::kByte:
49       return "Byte";
50     case OperandSize::kShort:
51       return "Short";
52   }
53   UNREACHABLE();
54   return "";
55 }
56 
57 
58 // static
ToByte(Bytecode bytecode)59 uint8_t Bytecodes::ToByte(Bytecode bytecode) {
60   return static_cast<uint8_t>(bytecode);
61 }
62 
63 
64 // static
FromByte(uint8_t value)65 Bytecode Bytecodes::FromByte(uint8_t value) {
66   Bytecode bytecode = static_cast<Bytecode>(value);
67   DCHECK(bytecode <= Bytecode::kLast);
68   return bytecode;
69 }
70 
71 
72 // static
Size(Bytecode bytecode)73 int Bytecodes::Size(Bytecode bytecode) {
74   DCHECK(bytecode <= Bytecode::kLast);
75   switch (bytecode) {
76 #define CASE(Name, ...)   \
77   case Bytecode::k##Name: \
78     return BytecodeTraits<__VA_ARGS__, OPERAND_TERM>::kSize;
79     BYTECODE_LIST(CASE)
80 #undef CASE
81   }
82   UNREACHABLE();
83   return 0;
84 }
85 
86 
87 // static
NumberOfOperands(Bytecode bytecode)88 int Bytecodes::NumberOfOperands(Bytecode bytecode) {
89   DCHECK(bytecode <= Bytecode::kLast);
90   switch (bytecode) {
91 #define CASE(Name, ...)   \
92   case Bytecode::k##Name: \
93     return BytecodeTraits<__VA_ARGS__, OPERAND_TERM>::kOperandCount;
94     BYTECODE_LIST(CASE)
95 #undef CASE
96   }
97   UNREACHABLE();
98   return 0;
99 }
100 
101 
102 // static
GetOperandType(Bytecode bytecode,int i)103 OperandType Bytecodes::GetOperandType(Bytecode bytecode, int i) {
104   DCHECK(bytecode <= Bytecode::kLast);
105   switch (bytecode) {
106 #define CASE(Name, ...)   \
107   case Bytecode::k##Name: \
108     return BytecodeTraits<__VA_ARGS__, OPERAND_TERM>::GetOperandType(i);
109     BYTECODE_LIST(CASE)
110 #undef CASE
111   }
112   UNREACHABLE();
113   return OperandType::kNone;
114 }
115 
116 
117 // static
GetOperandSize(Bytecode bytecode,int i)118 OperandSize Bytecodes::GetOperandSize(Bytecode bytecode, int i) {
119   DCHECK(bytecode <= Bytecode::kLast);
120   switch (bytecode) {
121 #define CASE(Name, ...)   \
122   case Bytecode::k##Name: \
123     return BytecodeTraits<__VA_ARGS__, OPERAND_TERM>::GetOperandSize(i);
124     BYTECODE_LIST(CASE)
125 #undef CASE
126   }
127   UNREACHABLE();
128   return OperandSize::kNone;
129 }
130 
131 
132 // static
GetOperandOffset(Bytecode bytecode,int i)133 int Bytecodes::GetOperandOffset(Bytecode bytecode, int i) {
134   DCHECK(bytecode <= Bytecode::kLast);
135   switch (bytecode) {
136 #define CASE(Name, ...)   \
137   case Bytecode::k##Name: \
138     return BytecodeTraits<__VA_ARGS__, OPERAND_TERM>::GetOperandOffset(i);
139     BYTECODE_LIST(CASE)
140 #undef CASE
141   }
142   UNREACHABLE();
143   return 0;
144 }
145 
146 
147 // static
SizeOfOperand(OperandType operand_type)148 OperandSize Bytecodes::SizeOfOperand(OperandType operand_type) {
149   switch (operand_type) {
150 #define CASE(Name, Size)     \
151   case OperandType::k##Name: \
152     return Size;
153     OPERAND_TYPE_LIST(CASE)
154 #undef CASE
155   }
156   UNREACHABLE();
157   return OperandSize::kNone;
158 }
159 
160 
161 // static
IsConditionalJumpImmediate(Bytecode bytecode)162 bool Bytecodes::IsConditionalJumpImmediate(Bytecode bytecode) {
163   return bytecode == Bytecode::kJumpIfTrue ||
164          bytecode == Bytecode::kJumpIfFalse ||
165          bytecode == Bytecode::kJumpIfToBooleanTrue ||
166          bytecode == Bytecode::kJumpIfToBooleanFalse ||
167          bytecode == Bytecode::kJumpIfNull ||
168          bytecode == Bytecode::kJumpIfUndefined;
169 }
170 
171 
172 // static
IsConditionalJumpConstant(Bytecode bytecode)173 bool Bytecodes::IsConditionalJumpConstant(Bytecode bytecode) {
174   return bytecode == Bytecode::kJumpIfTrueConstant ||
175          bytecode == Bytecode::kJumpIfFalseConstant ||
176          bytecode == Bytecode::kJumpIfToBooleanTrueConstant ||
177          bytecode == Bytecode::kJumpIfToBooleanFalseConstant ||
178          bytecode == Bytecode::kJumpIfNullConstant ||
179          bytecode == Bytecode::kJumpIfUndefinedConstant;
180 }
181 
182 
183 // static
IsConditionalJumpConstantWide(Bytecode bytecode)184 bool Bytecodes::IsConditionalJumpConstantWide(Bytecode bytecode) {
185   return bytecode == Bytecode::kJumpIfTrueConstantWide ||
186          bytecode == Bytecode::kJumpIfFalseConstantWide ||
187          bytecode == Bytecode::kJumpIfToBooleanTrueConstantWide ||
188          bytecode == Bytecode::kJumpIfToBooleanFalseConstantWide ||
189          bytecode == Bytecode::kJumpIfNullConstantWide ||
190          bytecode == Bytecode::kJumpIfUndefinedConstantWide;
191 }
192 
193 
194 // static
IsConditionalJump(Bytecode bytecode)195 bool Bytecodes::IsConditionalJump(Bytecode bytecode) {
196   return IsConditionalJumpImmediate(bytecode) ||
197          IsConditionalJumpConstant(bytecode) ||
198          IsConditionalJumpConstantWide(bytecode);
199 }
200 
201 
202 // static
IsJumpImmediate(Bytecode bytecode)203 bool Bytecodes::IsJumpImmediate(Bytecode bytecode) {
204   return bytecode == Bytecode::kJump || IsConditionalJumpImmediate(bytecode);
205 }
206 
207 
208 // static
IsJumpConstant(Bytecode bytecode)209 bool Bytecodes::IsJumpConstant(Bytecode bytecode) {
210   return bytecode == Bytecode::kJumpConstant ||
211          IsConditionalJumpConstant(bytecode);
212 }
213 
214 
215 // static
IsJumpConstantWide(Bytecode bytecode)216 bool Bytecodes::IsJumpConstantWide(Bytecode bytecode) {
217   return bytecode == Bytecode::kJumpConstantWide ||
218          IsConditionalJumpConstantWide(bytecode);
219 }
220 
221 
222 // static
IsJump(Bytecode bytecode)223 bool Bytecodes::IsJump(Bytecode bytecode) {
224   return IsJumpImmediate(bytecode) || IsJumpConstant(bytecode) ||
225          IsJumpConstantWide(bytecode);
226 }
227 
228 
229 // static
IsJumpOrReturn(Bytecode bytecode)230 bool Bytecodes::IsJumpOrReturn(Bytecode bytecode) {
231   return bytecode == Bytecode::kReturn || IsJump(bytecode);
232 }
233 
234 
235 // static
Decode(std::ostream & os,const uint8_t * bytecode_start,int parameter_count)236 std::ostream& Bytecodes::Decode(std::ostream& os, const uint8_t* bytecode_start,
237                                 int parameter_count) {
238   Vector<char> buf = Vector<char>::New(50);
239 
240   Bytecode bytecode = Bytecodes::FromByte(bytecode_start[0]);
241   int bytecode_size = Bytecodes::Size(bytecode);
242 
243   for (int i = 0; i < bytecode_size; i++) {
244     SNPrintF(buf, "%02x ", bytecode_start[i]);
245     os << buf.start();
246   }
247   const int kBytecodeColumnSize = 6;
248   for (int i = bytecode_size; i < kBytecodeColumnSize; i++) {
249     os << "   ";
250   }
251 
252   os << bytecode << " ";
253 
254   int number_of_operands = NumberOfOperands(bytecode);
255   for (int i = 0; i < number_of_operands; i++) {
256     OperandType op_type = GetOperandType(bytecode, i);
257     const uint8_t* operand_start =
258         &bytecode_start[GetOperandOffset(bytecode, i)];
259     switch (op_type) {
260       case interpreter::OperandType::kCount8:
261         os << "#" << static_cast<unsigned int>(*operand_start);
262         break;
263       case interpreter::OperandType::kCount16:
264         os << '#' << ReadUnalignedUInt16(operand_start);
265         break;
266       case interpreter::OperandType::kIdx8:
267         os << "[" << static_cast<unsigned int>(*operand_start) << "]";
268         break;
269       case interpreter::OperandType::kIdx16:
270         os << "[" << ReadUnalignedUInt16(operand_start) << "]";
271         break;
272       case interpreter::OperandType::kImm8:
273         os << "#" << static_cast<int>(static_cast<int8_t>(*operand_start));
274         break;
275       case interpreter::OperandType::kReg8:
276       case interpreter::OperandType::kMaybeReg8: {
277         Register reg = Register::FromOperand(*operand_start);
278         if (reg.is_function_context()) {
279           os << "<context>";
280         } else if (reg.is_function_closure()) {
281           os << "<closure>";
282         } else if (reg.is_new_target()) {
283           os << "<new.target>";
284         } else if (reg.is_parameter()) {
285           int parameter_index = reg.ToParameterIndex(parameter_count);
286           if (parameter_index == 0) {
287             os << "<this>";
288           } else {
289             os << "a" << parameter_index - 1;
290           }
291         } else {
292           os << "r" << reg.index();
293         }
294         break;
295       }
296       case interpreter::OperandType::kRegPair8: {
297         Register reg = Register::FromOperand(*operand_start);
298         if (reg.is_parameter()) {
299           int parameter_index = reg.ToParameterIndex(parameter_count);
300           DCHECK_NE(parameter_index, 0);
301           os << "a" << parameter_index - 1 << "-" << parameter_index;
302         } else {
303           os << "r" << reg.index() << "-" << reg.index() + 1;
304         }
305         break;
306       }
307       case interpreter::OperandType::kReg16: {
308         Register reg =
309             Register::FromWideOperand(ReadUnalignedUInt16(operand_start));
310         if (reg.is_parameter()) {
311           int parameter_index = reg.ToParameterIndex(parameter_count);
312           DCHECK_NE(parameter_index, 0);
313           os << "a" << parameter_index - 1;
314         } else {
315           os << "r" << reg.index();
316         }
317         break;
318       }
319       case interpreter::OperandType::kNone:
320         UNREACHABLE();
321         break;
322     }
323     if (i != number_of_operands - 1) {
324       os << ", ";
325     }
326   }
327   return os;
328 }
329 
330 
operator <<(std::ostream & os,const Bytecode & bytecode)331 std::ostream& operator<<(std::ostream& os, const Bytecode& bytecode) {
332   return os << Bytecodes::ToString(bytecode);
333 }
334 
335 
operator <<(std::ostream & os,const OperandType & operand_type)336 std::ostream& operator<<(std::ostream& os, const OperandType& operand_type) {
337   return os << Bytecodes::OperandTypeToString(operand_type);
338 }
339 
340 
operator <<(std::ostream & os,const OperandSize & operand_size)341 std::ostream& operator<<(std::ostream& os, const OperandSize& operand_size) {
342   return os << Bytecodes::OperandSizeToString(operand_size);
343 }
344 
345 
346 static const int kLastParamRegisterIndex =
347     -InterpreterFrameConstants::kLastParamFromRegisterPointer / kPointerSize;
348 static const int kFunctionClosureRegisterIndex =
349     -InterpreterFrameConstants::kFunctionFromRegisterPointer / kPointerSize;
350 static const int kFunctionContextRegisterIndex =
351     -InterpreterFrameConstants::kContextFromRegisterPointer / kPointerSize;
352 static const int kNewTargetRegisterIndex =
353     -InterpreterFrameConstants::kNewTargetFromRegisterPointer / kPointerSize;
354 
355 
356 // Registers occupy range 0-127 in 8-bit value leaving 128 unused values.
357 // Parameter indices are biased with the negative value kLastParamRegisterIndex
358 // for ease of access in the interpreter.
359 static const int kMaxParameterIndex = 128 + kLastParamRegisterIndex;
360 
361 
FromParameterIndex(int index,int parameter_count)362 Register Register::FromParameterIndex(int index, int parameter_count) {
363   DCHECK_GE(index, 0);
364   DCHECK_LT(index, parameter_count);
365   DCHECK_LE(parameter_count, kMaxParameterIndex + 1);
366   int register_index = kLastParamRegisterIndex - parameter_count + index + 1;
367   DCHECK_LT(register_index, 0);
368   DCHECK_GE(register_index, kMinInt8);
369   return Register(register_index);
370 }
371 
372 
ToParameterIndex(int parameter_count) const373 int Register::ToParameterIndex(int parameter_count) const {
374   DCHECK(is_parameter());
375   return index() - kLastParamRegisterIndex + parameter_count - 1;
376 }
377 
378 
function_closure()379 Register Register::function_closure() {
380   return Register(kFunctionClosureRegisterIndex);
381 }
382 
383 
is_function_closure() const384 bool Register::is_function_closure() const {
385   return index() == kFunctionClosureRegisterIndex;
386 }
387 
388 
function_context()389 Register Register::function_context() {
390   return Register(kFunctionContextRegisterIndex);
391 }
392 
393 
is_function_context() const394 bool Register::is_function_context() const {
395   return index() == kFunctionContextRegisterIndex;
396 }
397 
398 
new_target()399 Register Register::new_target() { return Register(kNewTargetRegisterIndex); }
400 
401 
is_new_target() const402 bool Register::is_new_target() const {
403   return index() == kNewTargetRegisterIndex;
404 }
405 
406 
MaxParameterIndex()407 int Register::MaxParameterIndex() { return kMaxParameterIndex; }
408 
409 
ToOperand() const410 uint8_t Register::ToOperand() const {
411   DCHECK_GE(index_, kMinInt8);
412   DCHECK_LE(index_, kMaxInt8);
413   return static_cast<uint8_t>(-index_);
414 }
415 
416 
FromOperand(uint8_t operand)417 Register Register::FromOperand(uint8_t operand) {
418   return Register(-static_cast<int8_t>(operand));
419 }
420 
421 
ToWideOperand() const422 uint16_t Register::ToWideOperand() const {
423   DCHECK_GE(index_, kMinInt16);
424   DCHECK_LE(index_, kMaxInt16);
425   return static_cast<uint16_t>(-index_);
426 }
427 
428 
FromWideOperand(uint16_t operand)429 Register Register::FromWideOperand(uint16_t operand) {
430   return Register(-static_cast<int16_t>(operand));
431 }
432 
433 
AreContiguous(Register reg1,Register reg2,Register reg3,Register reg4,Register reg5)434 bool Register::AreContiguous(Register reg1, Register reg2, Register reg3,
435                              Register reg4, Register reg5) {
436   if (reg1.index() + 1 != reg2.index()) {
437     return false;
438   }
439   if (reg3.is_valid() && reg2.index() + 1 != reg3.index()) {
440     return false;
441   }
442   if (reg4.is_valid() && reg3.index() + 1 != reg4.index()) {
443     return false;
444   }
445   if (reg5.is_valid() && reg4.index() + 1 != reg5.index()) {
446     return false;
447   }
448   return true;
449 }
450 
451 }  // namespace interpreter
452 }  // namespace internal
453 }  // namespace v8
454