1 // Copyright 2012 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef V8_X64_REGEXP_MACRO_ASSEMBLER_X64_H_
6 #define V8_X64_REGEXP_MACRO_ASSEMBLER_X64_H_
7 
8 #include "src/macro-assembler.h"
9 #include "src/x64/assembler-x64-inl.h"
10 #include "src/x64/assembler-x64.h"
11 #include "src/x64/macro-assembler-x64.h"
12 
13 namespace v8 {
14 namespace internal {
15 
16 #ifndef V8_INTERPRETED_REGEXP
17 
18 class RegExpMacroAssemblerX64: public NativeRegExpMacroAssembler {
19  public:
20   RegExpMacroAssemblerX64(Mode mode, int registers_to_save, Zone* zone);
21   virtual ~RegExpMacroAssemblerX64();
22   virtual int stack_limit_slack();
23   virtual void AdvanceCurrentPosition(int by);
24   virtual void AdvanceRegister(int reg, int by);
25   virtual void Backtrack();
26   virtual void Bind(Label* label);
27   virtual void CheckAtStart(Label* on_at_start);
28   virtual void CheckCharacter(uint32_t c, Label* on_equal);
29   virtual void CheckCharacterAfterAnd(uint32_t c,
30                                       uint32_t mask,
31                                       Label* on_equal);
32   virtual void CheckCharacterGT(uc16 limit, Label* on_greater);
33   virtual void CheckCharacterLT(uc16 limit, Label* on_less);
34   // A "greedy loop" is a loop that is both greedy and with a simple
35   // body. It has a particularly simple implementation.
36   virtual void CheckGreedyLoop(Label* on_tos_equals_current_position);
37   virtual void CheckNotAtStart(Label* on_not_at_start);
38   virtual void CheckNotBackReference(int start_reg, Label* on_no_match);
39   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
40                                                Label* on_no_match);
41   virtual void CheckNotCharacter(uint32_t c, Label* on_not_equal);
42   virtual void CheckNotCharacterAfterAnd(uint32_t c,
43                                          uint32_t mask,
44                                          Label* on_not_equal);
45   virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
46                                               uc16 minus,
47                                               uc16 mask,
48                                               Label* on_not_equal);
49   virtual void CheckCharacterInRange(uc16 from,
50                                      uc16 to,
51                                      Label* on_in_range);
52   virtual void CheckCharacterNotInRange(uc16 from,
53                                         uc16 to,
54                                         Label* on_not_in_range);
55   virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set);
56 
57   // Checks whether the given offset from the current position is before
58   // the end of the string.
59   virtual void CheckPosition(int cp_offset, Label* on_outside_input);
60   virtual bool CheckSpecialCharacterClass(uc16 type,
61                                           Label* on_no_match);
62   virtual void Fail();
63   virtual Handle<HeapObject> GetCode(Handle<String> source);
64   virtual void GoTo(Label* label);
65   virtual void IfRegisterGE(int reg, int comparand, Label* if_ge);
66   virtual void IfRegisterLT(int reg, int comparand, Label* if_lt);
67   virtual void IfRegisterEqPos(int reg, Label* if_eq);
68   virtual IrregexpImplementation Implementation();
69   virtual void LoadCurrentCharacter(int cp_offset,
70                                     Label* on_end_of_input,
71                                     bool check_bounds = true,
72                                     int characters = 1);
73   virtual void PopCurrentPosition();
74   virtual void PopRegister(int register_index);
75   virtual void PushBacktrack(Label* label);
76   virtual void PushCurrentPosition();
77   virtual void PushRegister(int register_index,
78                             StackCheckFlag check_stack_limit);
79   virtual void ReadCurrentPositionFromRegister(int reg);
80   virtual void ReadStackPointerFromRegister(int reg);
81   virtual void SetCurrentPositionFromEnd(int by);
82   virtual void SetRegister(int register_index, int to);
83   virtual bool Succeed();
84   virtual void WriteCurrentPositionToRegister(int reg, int cp_offset);
85   virtual void ClearRegisters(int reg_from, int reg_to);
86   virtual void WriteStackPointerToRegister(int reg);
87 
88   static Result Match(Handle<Code> regexp,
89                       Handle<String> subject,
90                       int* offsets_vector,
91                       int offsets_vector_length,
92                       int previous_index,
93                       Isolate* isolate);
94 
95   static Result Execute(Code* code,
96                         String* input,
97                         int start_offset,
98                         const byte* input_start,
99                         const byte* input_end,
100                         int* output,
101                         bool at_start);
102 
103   // Called from RegExp if the stack-guard is triggered.
104   // If the code object is relocated, the return address is fixed before
105   // returning.
106   static int CheckStackGuardState(Address* return_address,
107                                   Code* re_code,
108                                   Address re_frame);
109 
110  private:
111   // Offsets from rbp of function parameters and stored registers.
112   static const int kFramePointer = 0;
113   // Above the frame pointer - function parameters and return address.
114   static const int kReturn_eip = kFramePointer + kRegisterSize;
115   static const int kFrameAlign = kReturn_eip + kRegisterSize;
116 
117 #ifdef _WIN64
118   // Parameters (first four passed as registers, but with room on stack).
119   // In Microsoft 64-bit Calling Convention, there is room on the callers
120   // stack (before the return address) to spill parameter registers. We
121   // use this space to store the register passed parameters.
122   static const int kInputString = kFrameAlign;
123   // StartIndex is passed as 32 bit int.
124   static const int kStartIndex = kInputString + kRegisterSize;
125   static const int kInputStart = kStartIndex + kRegisterSize;
126   static const int kInputEnd = kInputStart + kRegisterSize;
127   static const int kRegisterOutput = kInputEnd + kRegisterSize;
128   // For the case of global regular expression, we have room to store at least
129   // one set of capture results.  For the case of non-global regexp, we ignore
130   // this value. NumOutputRegisters is passed as 32-bit value.  The upper
131   // 32 bit of this 64-bit stack slot may contain garbage.
132   static const int kNumOutputRegisters = kRegisterOutput + kRegisterSize;
133   static const int kStackHighEnd = kNumOutputRegisters + kRegisterSize;
134   // DirectCall is passed as 32 bit int (values 0 or 1).
135   static const int kDirectCall = kStackHighEnd + kRegisterSize;
136   static const int kIsolate = kDirectCall + kRegisterSize;
137 #else
138   // In AMD64 ABI Calling Convention, the first six integer parameters
139   // are passed as registers, and caller must allocate space on the stack
140   // if it wants them stored. We push the parameters after the frame pointer.
141   static const int kInputString = kFramePointer - kRegisterSize;
142   static const int kStartIndex = kInputString - kRegisterSize;
143   static const int kInputStart = kStartIndex - kRegisterSize;
144   static const int kInputEnd = kInputStart - kRegisterSize;
145   static const int kRegisterOutput = kInputEnd - kRegisterSize;
146 
147   // For the case of global regular expression, we have room to store at least
148   // one set of capture results.  For the case of non-global regexp, we ignore
149   // this value.
150   static const int kNumOutputRegisters = kRegisterOutput - kRegisterSize;
151   static const int kStackHighEnd = kFrameAlign;
152   static const int kDirectCall = kStackHighEnd + kRegisterSize;
153   static const int kIsolate = kDirectCall + kRegisterSize;
154 #endif
155 
156 #ifdef _WIN64
157   // Microsoft calling convention has three callee-saved registers
158   // (that we are using). We push these after the frame pointer.
159   static const int kBackup_rsi = kFramePointer - kRegisterSize;
160   static const int kBackup_rdi = kBackup_rsi - kRegisterSize;
161   static const int kBackup_rbx = kBackup_rdi - kRegisterSize;
162   static const int kLastCalleeSaveRegister = kBackup_rbx;
163 #else
164   // AMD64 Calling Convention has only one callee-save register that
165   // we use. We push this after the frame pointer (and after the
166   // parameters).
167   static const int kBackup_rbx = kNumOutputRegisters - kRegisterSize;
168   static const int kLastCalleeSaveRegister = kBackup_rbx;
169 #endif
170 
171   static const int kSuccessfulCaptures = kLastCalleeSaveRegister - kPointerSize;
172   // When adding local variables remember to push space for them in
173   // the frame in GetCode.
174   static const int kInputStartMinusOne = kSuccessfulCaptures - kPointerSize;
175 
176   // First register address. Following registers are below it on the stack.
177   static const int kRegisterZero = kInputStartMinusOne - kPointerSize;
178 
179   // Initial size of code buffer.
180   static const size_t kRegExpCodeSize = 1024;
181 
182   // Load a number of characters at the given offset from the
183   // current position, into the current-character register.
184   void LoadCurrentCharacterUnchecked(int cp_offset, int character_count);
185 
186   // Check whether preemption has been requested.
187   void CheckPreemption();
188 
189   // Check whether we are exceeding the stack limit on the backtrack stack.
190   void CheckStackLimit();
191 
192   // Generate a call to CheckStackGuardState.
193   void CallCheckStackGuardState();
194 
195   // The rbp-relative location of a regexp register.
196   Operand register_location(int register_index);
197 
198   // The register containing the current character after LoadCurrentCharacter.
current_character()199   inline Register current_character() { return rdx; }
200 
201   // The register containing the backtrack stack top. Provides a meaningful
202   // name to the register.
backtrack_stackpointer()203   inline Register backtrack_stackpointer() { return rcx; }
204 
205   // The registers containing a self pointer to this code's Code object.
code_object_pointer()206   inline Register code_object_pointer() { return r8; }
207 
208   // Byte size of chars in the string to match (decided by the Mode argument)
char_size()209   inline int char_size() { return static_cast<int>(mode_); }
210 
211   // Equivalent to a conditional branch to the label, unless the label
212   // is NULL, in which case it is a conditional Backtrack.
213   void BranchOrBacktrack(Condition condition, Label* to);
214 
MarkPositionForCodeRelativeFixup()215   void MarkPositionForCodeRelativeFixup() {
216     code_relative_fixup_positions_.Add(masm_.pc_offset(), zone());
217   }
218 
219   void FixupCodeRelativePositions();
220 
221   // Call and return internally in the generated code in a way that
222   // is GC-safe (i.e., doesn't leave absolute code addresses on the stack)
223   inline void SafeCall(Label* to);
224   inline void SafeCallTarget(Label* label);
225   inline void SafeReturn();
226 
227   // Pushes the value of a register on the backtrack stack. Decrements the
228   // stack pointer (rcx) by a word size and stores the register's value there.
229   inline void Push(Register source);
230 
231   // Pushes a value on the backtrack stack. Decrements the stack pointer (rcx)
232   // by a word size and stores the value there.
233   inline void Push(Immediate value);
234 
235   // Pushes the Code object relative offset of a label on the backtrack stack
236   // (i.e., a backtrack target). Decrements the stack pointer (rcx)
237   // by a word size and stores the value there.
238   inline void Push(Label* label);
239 
240   // Pops a value from the backtrack stack. Reads the word at the stack pointer
241   // (rcx) and increments it by a word size.
242   inline void Pop(Register target);
243 
244   // Drops the top value from the backtrack stack without reading it.
245   // Increments the stack pointer (rcx) by a word size.
246   inline void Drop();
247 
248   inline void ReadPositionFromRegister(Register dst, int reg);
249 
isolate()250   Isolate* isolate() const { return masm_.isolate(); }
251 
252   MacroAssembler masm_;
253   MacroAssembler::NoRootArrayScope no_root_array_scope_;
254 
255   ZoneList<int> code_relative_fixup_positions_;
256 
257   // Which mode to generate code for (LATIN1 or UC16).
258   Mode mode_;
259 
260   // One greater than maximal register index actually used.
261   int num_registers_;
262 
263   // Number of registers to output at the end (the saved registers
264   // are always 0..num_saved_registers_-1)
265   int num_saved_registers_;
266 
267   // Labels used internally.
268   Label entry_label_;
269   Label start_label_;
270   Label success_label_;
271   Label backtrack_label_;
272   Label exit_label_;
273   Label check_preempt_label_;
274   Label stack_overflow_label_;
275 };
276 
277 #endif  // V8_INTERPRETED_REGEXP
278 
279 }}  // namespace v8::internal
280 
281 #endif  // V8_X64_REGEXP_MACRO_ASSEMBLER_X64_H_
282