1// Copyright 2013 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#ifndef V8_REGEXP_ARM64_REGEXP_MACRO_ASSEMBLER_ARM64_H_
6#define V8_REGEXP_ARM64_REGEXP_MACRO_ASSEMBLER_ARM64_H_
7
8#include "src/arm64/assembler-arm64.h"
9#include "src/macro-assembler.h"
10#include "src/regexp/regexp-macro-assembler.h"
11
12namespace v8 {
13namespace internal {
14
15
16#ifndef V8_INTERPRETED_REGEXP
17class RegExpMacroAssemblerARM64: public NativeRegExpMacroAssembler {
18 public:
19  RegExpMacroAssemblerARM64(Isolate* isolate, Zone* zone, Mode mode,
20                            int registers_to_save);
21  virtual ~RegExpMacroAssemblerARM64();
22  virtual void AbortedCodeGeneration() { masm_->AbortedCodeGeneration(); }
23  virtual int stack_limit_slack();
24  virtual void AdvanceCurrentPosition(int by);
25  virtual void AdvanceRegister(int reg, int by);
26  virtual void Backtrack();
27  virtual void Bind(Label* label);
28  virtual void CheckAtStart(Label* on_at_start);
29  virtual void CheckCharacter(unsigned c, Label* on_equal);
30  virtual void CheckCharacterAfterAnd(unsigned c,
31                                      unsigned mask,
32                                      Label* on_equal);
33  virtual void CheckCharacterGT(uc16 limit, Label* on_greater);
34  virtual void CheckCharacterLT(uc16 limit, Label* on_less);
35  virtual void CheckCharacters(Vector<const uc16> str,
36                               int cp_offset,
37                               Label* on_failure,
38                               bool check_end_of_string);
39  // A "greedy loop" is a loop that is both greedy and with a simple
40  // body. It has a particularly simple implementation.
41  virtual void CheckGreedyLoop(Label* on_tos_equals_current_position);
42  virtual void CheckNotAtStart(int cp_offset, Label* on_not_at_start);
43  virtual void CheckNotBackReference(int start_reg, bool read_backward,
44                                     Label* on_no_match);
45  virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
46                                               bool read_backward, bool unicode,
47                                               Label* on_no_match);
48  virtual void CheckNotCharacter(unsigned c, Label* on_not_equal);
49  virtual void CheckNotCharacterAfterAnd(unsigned c,
50                                         unsigned mask,
51                                         Label* on_not_equal);
52  virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
53                                              uc16 minus,
54                                              uc16 mask,
55                                              Label* on_not_equal);
56  virtual void CheckCharacterInRange(uc16 from,
57                                     uc16 to,
58                                     Label* on_in_range);
59  virtual void CheckCharacterNotInRange(uc16 from,
60                                        uc16 to,
61                                        Label* on_not_in_range);
62  virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set);
63
64  // Checks whether the given offset from the current position is before
65  // the end of the string.
66  virtual void CheckPosition(int cp_offset, Label* on_outside_input);
67  virtual bool CheckSpecialCharacterClass(uc16 type,
68                                          Label* on_no_match);
69  virtual void Fail();
70  virtual Handle<HeapObject> GetCode(Handle<String> source);
71  virtual void GoTo(Label* label);
72  virtual void IfRegisterGE(int reg, int comparand, Label* if_ge);
73  virtual void IfRegisterLT(int reg, int comparand, Label* if_lt);
74  virtual void IfRegisterEqPos(int reg, Label* if_eq);
75  virtual IrregexpImplementation Implementation();
76  virtual void LoadCurrentCharacter(int cp_offset,
77                                    Label* on_end_of_input,
78                                    bool check_bounds = true,
79                                    int characters = 1);
80  virtual void PopCurrentPosition();
81  virtual void PopRegister(int register_index);
82  virtual void PushBacktrack(Label* label);
83  virtual void PushCurrentPosition();
84  virtual void PushRegister(int register_index,
85                            StackCheckFlag check_stack_limit);
86  virtual void ReadCurrentPositionFromRegister(int reg);
87  virtual void ReadStackPointerFromRegister(int reg);
88  virtual void SetCurrentPositionFromEnd(int by);
89  virtual void SetRegister(int register_index, int to);
90  virtual bool Succeed();
91  virtual void WriteCurrentPositionToRegister(int reg, int cp_offset);
92  virtual void ClearRegisters(int reg_from, int reg_to);
93  virtual void WriteStackPointerToRegister(int reg);
94  virtual bool CanReadUnaligned();
95
96  // Called from RegExp if the stack-guard is triggered.
97  // If the code object is relocated, the return address is fixed before
98  // returning.
99  static int CheckStackGuardState(Address* return_address,
100                                  Code* re_code,
101                                  Address re_frame,
102                                  int start_offset,
103                                  const byte** input_start,
104                                  const byte** input_end);
105
106 private:
107  // Above the frame pointer - Stored registers and stack passed parameters.
108  // Callee-saved registers x19-x29, where x29 is the old frame pointer.
109  static const int kCalleeSavedRegisters = 0;
110  // Return address.
111  // It is placed above the 11 callee-saved registers.
112  static const int kReturnAddress = kCalleeSavedRegisters + 11 * kPointerSize;
113  static const int kSecondaryReturnAddress = kReturnAddress + kPointerSize;
114  // Stack parameter placed by caller.
115  static const int kIsolate = kSecondaryReturnAddress + kPointerSize;
116
117  // Below the frame pointer.
118  // Register parameters stored by setup code.
119  static const int kDirectCall = kCalleeSavedRegisters - kPointerSize;
120  static const int kStackBase = kDirectCall - kPointerSize;
121  static const int kOutputSize = kStackBase - kPointerSize;
122  static const int kInput = kOutputSize - kPointerSize;
123  // When adding local variables remember to push space for them in
124  // the frame in GetCode.
125  static const int kSuccessCounter = kInput - kPointerSize;
126  // First position register address on the stack. Following positions are
127  // below it. A position is a 32 bit value.
128  static const int kFirstRegisterOnStack = kSuccessCounter - kWRegSize;
129  // A capture is a 64 bit value holding two position.
130  static const int kFirstCaptureOnStack = kSuccessCounter - kXRegSize;
131
132  // Initial size of code buffer.
133  static const size_t kRegExpCodeSize = 1024;
134
135  // When initializing registers to a non-position value we can unroll
136  // the loop. Set the limit of registers to unroll.
137  static const int kNumRegistersToUnroll = 16;
138
139  // We are using x0 to x7 as a register cache. Each hardware register must
140  // contain one capture, that is two 32 bit registers. We can cache at most
141  // 16 registers.
142  static const int kNumCachedRegisters = 16;
143
144  // Load a number of characters at the given offset from the
145  // current position, into the current-character register.
146  void LoadCurrentCharacterUnchecked(int cp_offset, int character_count);
147
148  // Check whether preemption has been requested.
149  void CheckPreemption();
150
151  // Check whether we are exceeding the stack limit on the backtrack stack.
152  void CheckStackLimit();
153
154  // Generate a call to CheckStackGuardState.
155  void CallCheckStackGuardState(Register scratch);
156
157  // Location of a 32 bit position register.
158  MemOperand register_location(int register_index);
159
160  // Location of a 64 bit capture, combining two position registers.
161  MemOperand capture_location(int register_index, Register scratch);
162
163  // Register holding the current input position as negative offset from
164  // the end of the string.
165  Register current_input_offset() { return w21; }
166
167  // The register containing the current character after LoadCurrentCharacter.
168  Register current_character() { return w22; }
169
170  // Register holding address of the end of the input string.
171  Register input_end() { return x25; }
172
173  // Register holding address of the start of the input string.
174  Register input_start() { return x26; }
175
176  // Register holding the offset from the start of the string where we should
177  // start matching.
178  Register start_offset() { return w27; }
179
180  // Pointer to the output array's first element.
181  Register output_array() { return x28; }
182
183  // Register holding the frame address. Local variables, parameters and
184  // regexp registers are addressed relative to this.
185  Register frame_pointer() { return fp; }
186
187  // The register containing the backtrack stack top. Provides a meaningful
188  // name to the register.
189  Register backtrack_stackpointer() { return x23; }
190
191  // Register holding pointer to the current code object.
192  Register code_pointer() { return x20; }
193
194  // Register holding the value used for clearing capture registers.
195  Register string_start_minus_one() { return w24; }
196  // The top 32 bit of this register is used to store this value
197  // twice. This is used for clearing more than one register at a time.
198  Register twice_non_position_value() { return x24; }
199
200  // Byte size of chars in the string to match (decided by the Mode argument)
201  int char_size() { return static_cast<int>(mode_); }
202
203  // Equivalent to a conditional branch to the label, unless the label
204  // is NULL, in which case it is a conditional Backtrack.
205  void BranchOrBacktrack(Condition condition, Label* to);
206
207  // Compares reg against immmediate before calling BranchOrBacktrack.
208  // It makes use of the Cbz and Cbnz instructions.
209  void CompareAndBranchOrBacktrack(Register reg,
210                                   int immediate,
211                                   Condition condition,
212                                   Label* to);
213
214  inline void CallIf(Label* to, Condition condition);
215
216  // Save and restore the link register on the stack in a way that
217  // is GC-safe.
218  inline void SaveLinkRegister();
219  inline void RestoreLinkRegister();
220
221  // Pushes the value of a register on the backtrack stack. Decrements the
222  // stack pointer by a word size and stores the register's value there.
223  inline void Push(Register source);
224
225  // Pops a value from the backtrack stack. Reads the word at the stack pointer
226  // and increments it by a word size.
227  inline void Pop(Register target);
228
229  // This state indicates where the register actually is.
230  enum RegisterState {
231    STACKED,     // Resides in memory.
232    CACHED_LSW,  // Least Significant Word of a 64 bit hardware register.
233    CACHED_MSW   // Most Significant Word of a 64 bit hardware register.
234  };
235
236  RegisterState GetRegisterState(int register_index) {
237    DCHECK(register_index >= 0);
238    if (register_index >= kNumCachedRegisters) {
239      return STACKED;
240    } else {
241      if ((register_index % 2) == 0) {
242        return CACHED_LSW;
243      } else {
244        return CACHED_MSW;
245      }
246    }
247  }
248
249  // Store helper that takes the state of the register into account.
250  inline void StoreRegister(int register_index, Register source);
251
252  // Returns a hardware W register that holds the value of the capture
253  // register.
254  //
255  // This function will try to use an existing cache register (w0-w7) for the
256  // result. Otherwise, it will load the value into maybe_result.
257  //
258  // If the returned register is anything other than maybe_result, calling code
259  // must not write to it.
260  inline Register GetRegister(int register_index, Register maybe_result);
261
262  // Returns the harware register (x0-x7) holding the value of the capture
263  // register.
264  // This assumes that the state of the register is not STACKED.
265  inline Register GetCachedRegister(int register_index);
266
267  Isolate* isolate() const { return masm_->isolate(); }
268
269  MacroAssembler* masm_;
270
271  // Which mode to generate code for (LATIN1 or UC16).
272  Mode mode_;
273
274  // One greater than maximal register index actually used.
275  int num_registers_;
276
277  // Number of registers to output at the end (the saved registers
278  // are always 0..num_saved_registers_-1)
279  int num_saved_registers_;
280
281  // Labels used internally.
282  Label entry_label_;
283  Label start_label_;
284  Label success_label_;
285  Label backtrack_label_;
286  Label exit_label_;
287  Label check_preempt_label_;
288  Label stack_overflow_label_;
289};
290
291#endif  // V8_INTERPRETED_REGEXP
292
293
294}  // namespace internal
295}  // namespace v8
296
297#endif  // V8_REGEXP_ARM64_REGEXP_MACRO_ASSEMBLER_ARM64_H_
298