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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_REGEXP_X64_REGEXP_MACRO_ASSEMBLER_X64_H_
6 #define V8_REGEXP_X64_REGEXP_MACRO_ASSEMBLER_X64_H_
7 
8 #include "src/macro-assembler.h"
9 #include "src/regexp/regexp-macro-assembler.h"
10 #include "src/x64/assembler-x64.h"
11 #include "src/zone/zone-chunk-list.h"
12 
13 namespace v8 {
14 namespace internal {
15 
16 #ifndef V8_INTERPRETED_REGEXP
17 
18 class RegExpMacroAssemblerX64: public NativeRegExpMacroAssembler {
19  public:
20   RegExpMacroAssemblerX64(Isolate* isolate, Zone* zone, Mode mode,
21                           int registers_to_save);
22   virtual ~RegExpMacroAssemblerX64();
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(uint32_t c, Label* on_equal);
30   virtual void CheckCharacterAfterAnd(uint32_t c,
31                                       uint32_t mask,
32                                       Label* on_equal);
33   virtual void CheckCharacterGT(uc16 limit, Label* on_greater);
34   virtual void CheckCharacterLT(uc16 limit, Label* on_less);
35   // A "greedy loop" is a loop that is both greedy and with a simple
36   // body. It has a particularly simple implementation.
37   virtual void CheckGreedyLoop(Label* on_tos_equals_current_position);
38   virtual void CheckNotAtStart(int cp_offset, Label* on_not_at_start);
39   virtual void CheckNotBackReference(int start_reg, bool read_backward,
40                                      Label* on_no_match);
41   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
42                                                bool read_backward, bool unicode,
43                                                Label* on_no_match);
44   virtual void CheckNotCharacter(uint32_t c, Label* on_not_equal);
45   virtual void CheckNotCharacterAfterAnd(uint32_t c,
46                                          uint32_t mask,
47                                          Label* on_not_equal);
48   virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
49                                               uc16 minus,
50                                               uc16 mask,
51                                               Label* on_not_equal);
52   virtual void CheckCharacterInRange(uc16 from,
53                                      uc16 to,
54                                      Label* on_in_range);
55   virtual void CheckCharacterNotInRange(uc16 from,
56                                         uc16 to,
57                                         Label* on_not_in_range);
58   virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set);
59 
60   // Checks whether the given offset from the current position is before
61   // the end of the string.
62   virtual void CheckPosition(int cp_offset, Label* on_outside_input);
63   virtual bool CheckSpecialCharacterClass(uc16 type,
64                                           Label* on_no_match);
65   virtual void Fail();
66   virtual Handle<HeapObject> GetCode(Handle<String> source);
67   virtual void GoTo(Label* label);
68   virtual void IfRegisterGE(int reg, int comparand, Label* if_ge);
69   virtual void IfRegisterLT(int reg, int comparand, Label* if_lt);
70   virtual void IfRegisterEqPos(int reg, Label* if_eq);
71   virtual IrregexpImplementation Implementation();
72   virtual void LoadCurrentCharacter(int cp_offset,
73                                     Label* on_end_of_input,
74                                     bool check_bounds = true,
75                                     int characters = 1);
76   virtual void PopCurrentPosition();
77   virtual void PopRegister(int register_index);
78   virtual void PushBacktrack(Label* label);
79   virtual void PushCurrentPosition();
80   virtual void PushRegister(int register_index,
81                             StackCheckFlag check_stack_limit);
82   virtual void ReadCurrentPositionFromRegister(int reg);
83   virtual void ReadStackPointerFromRegister(int reg);
84   virtual void SetCurrentPositionFromEnd(int by);
85   virtual void SetRegister(int register_index, int to);
86   virtual bool Succeed();
87   virtual void WriteCurrentPositionToRegister(int reg, int cp_offset);
88   virtual void ClearRegisters(int reg_from, int reg_to);
89   virtual void WriteStackPointerToRegister(int reg);
90 
91   static Result Match(Handle<Code> regexp,
92                       Handle<String> subject,
93                       int* offsets_vector,
94                       int offsets_vector_length,
95                       int previous_index,
96                       Isolate* isolate);
97 
98   static Result Execute(Code* code,
99                         String* input,
100                         int start_offset,
101                         const byte* input_start,
102                         const byte* input_end,
103                         int* output,
104                         bool at_start);
105 
106   // Called from RegExp if the stack-guard is triggered.
107   // If the code object is relocated, the return address is fixed before
108   // returning.
109   static int CheckStackGuardState(Address* return_address,
110                                   Code* re_code,
111                                   Address re_frame);
112 
113  private:
114   // Offsets from rbp of function parameters and stored registers.
115   static const int kFramePointer = 0;
116   // Above the frame pointer - function parameters and return address.
117   static const int kReturn_eip = kFramePointer + kRegisterSize;
118   static const int kFrameAlign = kReturn_eip + kRegisterSize;
119 
120 #ifdef _WIN64
121   // Parameters (first four passed as registers, but with room on stack).
122   // In Microsoft 64-bit Calling Convention, there is room on the callers
123   // stack (before the return address) to spill parameter registers. We
124   // use this space to store the register passed parameters.
125   static const int kInputString = kFrameAlign;
126   // StartIndex is passed as 32 bit int.
127   static const int kStartIndex = kInputString + kRegisterSize;
128   static const int kInputStart = kStartIndex + kRegisterSize;
129   static const int kInputEnd = kInputStart + kRegisterSize;
130   static const int kRegisterOutput = kInputEnd + kRegisterSize;
131   // For the case of global regular expression, we have room to store at least
132   // one set of capture results.  For the case of non-global regexp, we ignore
133   // this value. NumOutputRegisters is passed as 32-bit value.  The upper
134   // 32 bit of this 64-bit stack slot may contain garbage.
135   static const int kNumOutputRegisters = kRegisterOutput + kRegisterSize;
136   static const int kStackHighEnd = kNumOutputRegisters + kRegisterSize;
137   // DirectCall is passed as 32 bit int (values 0 or 1).
138   static const int kDirectCall = kStackHighEnd + kRegisterSize;
139   static const int kIsolate = kDirectCall + kRegisterSize;
140 #else
141   // In AMD64 ABI Calling Convention, the first six integer parameters
142   // are passed as registers, and caller must allocate space on the stack
143   // if it wants them stored. We push the parameters after the frame pointer.
144   static const int kInputString = kFramePointer - kRegisterSize;
145   static const int kStartIndex = kInputString - kRegisterSize;
146   static const int kInputStart = kStartIndex - kRegisterSize;
147   static const int kInputEnd = kInputStart - kRegisterSize;
148   static const int kRegisterOutput = kInputEnd - kRegisterSize;
149 
150   // For the case of global regular expression, we have room to store at least
151   // one set of capture results.  For the case of non-global regexp, we ignore
152   // this value.
153   static const int kNumOutputRegisters = kRegisterOutput - kRegisterSize;
154   static const int kStackHighEnd = kFrameAlign;
155   static const int kDirectCall = kStackHighEnd + kRegisterSize;
156   static const int kIsolate = kDirectCall + kRegisterSize;
157 #endif
158 
159 #ifdef _WIN64
160   // Microsoft calling convention has three callee-saved registers
161   // (that we are using). We push these after the frame pointer.
162   static const int kBackup_rsi = kFramePointer - kRegisterSize;
163   static const int kBackup_rdi = kBackup_rsi - kRegisterSize;
164   static const int kBackup_rbx = kBackup_rdi - kRegisterSize;
165   static const int kLastCalleeSaveRegister = kBackup_rbx;
166 #else
167   // AMD64 Calling Convention has only one callee-save register that
168   // we use. We push this after the frame pointer (and after the
169   // parameters).
170   static const int kBackup_rbx = kNumOutputRegisters - kRegisterSize;
171   static const int kLastCalleeSaveRegister = kBackup_rbx;
172 #endif
173 
174   static const int kSuccessfulCaptures = kLastCalleeSaveRegister - kPointerSize;
175   // When adding local variables remember to push space for them in
176   // the frame in GetCode.
177   static const int kStringStartMinusOne = kSuccessfulCaptures - kPointerSize;
178 
179   // First register address. Following registers are below it on the stack.
180   static const int kRegisterZero = kStringStartMinusOne - kPointerSize;
181 
182   // Initial size of code buffer.
183   static const size_t kRegExpCodeSize = 1024;
184 
185   // Load a number of characters at the given offset from the
186   // current position, into the current-character register.
187   void LoadCurrentCharacterUnchecked(int cp_offset, int character_count);
188 
189   // Check whether preemption has been requested.
190   void CheckPreemption();
191 
192   // Check whether we are exceeding the stack limit on the backtrack stack.
193   void CheckStackLimit();
194 
195   // Generate a call to CheckStackGuardState.
196   void CallCheckStackGuardState();
197 
198   // The rbp-relative location of a regexp register.
199   Operand register_location(int register_index);
200 
201   // The register containing the current character after LoadCurrentCharacter.
current_character()202   inline Register current_character() { return rdx; }
203 
204   // The register containing the backtrack stack top. Provides a meaningful
205   // name to the register.
backtrack_stackpointer()206   inline Register backtrack_stackpointer() { return rcx; }
207 
208   // The registers containing a self pointer to this code's Code object.
code_object_pointer()209   inline Register code_object_pointer() { return r8; }
210 
211   // Byte size of chars in the string to match (decided by the Mode argument)
char_size()212   inline int char_size() { return static_cast<int>(mode_); }
213 
214   // Equivalent to a conditional branch to the label, unless the label
215   // is nullptr, in which case it is a conditional Backtrack.
216   void BranchOrBacktrack(Condition condition, Label* to);
217 
MarkPositionForCodeRelativeFixup()218   void MarkPositionForCodeRelativeFixup() {
219     code_relative_fixup_positions_.push_back(masm_.pc_offset());
220   }
221 
222   void FixupCodeRelativePositions();
223 
224   // Call and return internally in the generated code in a way that
225   // is GC-safe (i.e., doesn't leave absolute code addresses on the stack)
226   inline void SafeCall(Label* to);
227   inline void SafeCallTarget(Label* label);
228   inline void SafeReturn();
229 
230   // Pushes the value of a register on the backtrack stack. Decrements the
231   // stack pointer (rcx) by a word size and stores the register's value there.
232   inline void Push(Register source);
233 
234   // Pushes a value on the backtrack stack. Decrements the stack pointer (rcx)
235   // by a word size and stores the value there.
236   inline void Push(Immediate value);
237 
238   // Pushes the Code object relative offset of a label on the backtrack stack
239   // (i.e., a backtrack target). Decrements the stack pointer (rcx)
240   // by a word size and stores the value there.
241   inline void Push(Label* label);
242 
243   // Pops a value from the backtrack stack. Reads the word at the stack pointer
244   // (rcx) and increments it by a word size.
245   inline void Pop(Register target);
246 
247   // Drops the top value from the backtrack stack without reading it.
248   // Increments the stack pointer (rcx) by a word size.
249   inline void Drop();
250 
251   inline void ReadPositionFromRegister(Register dst, int reg);
252 
isolate()253   Isolate* isolate() const { return masm_.isolate(); }
254 
255   MacroAssembler masm_;
256   NoRootArrayScope no_root_array_scope_;
257 
258   ZoneChunkList<int> code_relative_fixup_positions_;
259 
260   // Which mode to generate code for (LATIN1 or UC16).
261   Mode mode_;
262 
263   // One greater than maximal register index actually used.
264   int num_registers_;
265 
266   // Number of registers to output at the end (the saved registers
267   // are always 0..num_saved_registers_-1)
268   int num_saved_registers_;
269 
270   // Labels used internally.
271   Label entry_label_;
272   Label start_label_;
273   Label success_label_;
274   Label backtrack_label_;
275   Label exit_label_;
276   Label check_preempt_label_;
277   Label stack_overflow_label_;
278 };
279 
280 #endif  // V8_INTERPRETED_REGEXP
281 
282 }  // namespace internal
283 }  // namespace v8
284 
285 #endif  // V8_REGEXP_X64_REGEXP_MACRO_ASSEMBLER_X64_H_
286