1 // Copyright 2011 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_MIPS_REGEXP_MACRO_ASSEMBLER_MIPS_H_
6 #define V8_REGEXP_MIPS_REGEXP_MACRO_ASSEMBLER_MIPS_H_
7 
8 #include "src/macro-assembler.h"
9 #include "src/mips/assembler-mips.h"
10 #include "src/regexp/regexp-macro-assembler.h"
11 
12 namespace v8 {
13 namespace internal {
14 
15 #ifndef V8_INTERPRETED_REGEXP
16 class RegExpMacroAssemblerMIPS: public NativeRegExpMacroAssembler {
17  public:
18   RegExpMacroAssemblerMIPS(Isolate* isolate, Zone* zone, Mode mode,
19                            int registers_to_save);
20   virtual ~RegExpMacroAssemblerMIPS();
21   virtual int stack_limit_slack();
22   virtual void AdvanceCurrentPosition(int by);
23   virtual void AdvanceRegister(int reg, int by);
24   virtual void Backtrack();
25   virtual void Bind(Label* label);
26   virtual void CheckAtStart(Label* on_at_start);
27   virtual void CheckCharacter(uint32_t c, Label* on_equal);
28   virtual void CheckCharacterAfterAnd(uint32_t c,
29                                       uint32_t mask,
30                                       Label* on_equal);
31   virtual void CheckCharacterGT(uc16 limit, Label* on_greater);
32   virtual void CheckCharacterLT(uc16 limit, Label* on_less);
33   // A "greedy loop" is a loop that is both greedy and with a simple
34   // body. It has a particularly simple implementation.
35   virtual void CheckGreedyLoop(Label* on_tos_equals_current_position);
36   virtual void CheckNotAtStart(int cp_offset, Label* on_not_at_start);
37   virtual void CheckNotBackReference(int start_reg, bool read_backward,
38                                      Label* on_no_match);
39   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
40                                                bool read_backward, bool unicode,
41                                                Label* on_no_match);
42   virtual void CheckNotCharacter(uint32_t c, Label* on_not_equal);
43   virtual void CheckNotCharacterAfterAnd(uint32_t c,
44                                          uint32_t mask,
45                                          Label* on_not_equal);
46   virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
47                                               uc16 minus,
48                                               uc16 mask,
49                                               Label* on_not_equal);
50   virtual void CheckCharacterInRange(uc16 from,
51                                      uc16 to,
52                                      Label* on_in_range);
53   virtual void CheckCharacterNotInRange(uc16 from,
54                                         uc16 to,
55                                         Label* on_not_in_range);
56   virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set);
57 
58   // Checks whether the given offset from the current position is before
59   // the end of the string.
60   virtual void CheckPosition(int cp_offset, Label* on_outside_input);
61   virtual bool CheckSpecialCharacterClass(uc16 type,
62                                           Label* on_no_match);
63   virtual void Fail();
64   virtual Handle<HeapObject> GetCode(Handle<String> source);
65   virtual void GoTo(Label* label);
66   virtual void IfRegisterGE(int reg, int comparand, Label* if_ge);
67   virtual void IfRegisterLT(int reg, int comparand, Label* if_lt);
68   virtual void IfRegisterEqPos(int reg, Label* if_eq);
69   virtual IrregexpImplementation Implementation();
70   virtual void LoadCurrentCharacter(int cp_offset,
71                                     Label* on_end_of_input,
72                                     bool check_bounds = true,
73                                     int characters = 1);
74   virtual void PopCurrentPosition();
75   virtual void PopRegister(int register_index);
76   virtual void PushBacktrack(Label* label);
77   virtual void PushCurrentPosition();
78   virtual void PushRegister(int register_index,
79                             StackCheckFlag check_stack_limit);
80   virtual void ReadCurrentPositionFromRegister(int reg);
81   virtual void ReadStackPointerFromRegister(int reg);
82   virtual void SetCurrentPositionFromEnd(int by);
83   virtual void SetRegister(int register_index, int to);
84   virtual bool Succeed();
85   virtual void WriteCurrentPositionToRegister(int reg, int cp_offset);
86   virtual void ClearRegisters(int reg_from, int reg_to);
87   virtual void WriteStackPointerToRegister(int reg);
88   virtual bool CanReadUnaligned();
89 
90   // Called from RegExp if the stack-guard is triggered.
91   // If the code object is relocated, the return address is fixed before
92   // returning.
93   static int CheckStackGuardState(Address* return_address,
94                                   Code* re_code,
95                                   Address re_frame);
96 
97  private:
98   // Offsets from frame_pointer() of function parameters and stored registers.
99   static const int kFramePointer = 0;
100 
101   // Above the frame pointer - Stored registers and stack passed parameters.
102   // Registers s0 to s7, fp, and ra.
103   static const int kStoredRegisters = kFramePointer;
104   // Return address (stored from link register, read into pc on return).
105   static const int kReturnAddress = kStoredRegisters + 9 * kPointerSize;
106   // Stack frame header.
107   static const int kStackFrameHeader = kReturnAddress;
108   // Stack parameters placed by caller.
109   static const int kRegisterOutput = kStackFrameHeader + 20;
110   static const int kNumOutputRegisters = kRegisterOutput + kPointerSize;
111   static const int kStackHighEnd = kNumOutputRegisters + kPointerSize;
112   static const int kDirectCall = kStackHighEnd + kPointerSize;
113   static const int kIsolate = kDirectCall + kPointerSize;
114 
115   // Below the frame pointer.
116   // Register parameters stored by setup code.
117   static const int kInputEnd = kFramePointer - kPointerSize;
118   static const int kInputStart = kInputEnd - kPointerSize;
119   static const int kStartIndex = kInputStart - kPointerSize;
120   static const int kInputString = kStartIndex - kPointerSize;
121   // When adding local variables remember to push space for them in
122   // the frame in GetCode.
123   static const int kSuccessfulCaptures = kInputString - kPointerSize;
124   static const int kStringStartMinusOne = kSuccessfulCaptures - kPointerSize;
125   // First register address. Following registers are below it on the stack.
126   static const int kRegisterZero = kStringStartMinusOne - kPointerSize;
127 
128   // Initial size of code buffer.
129   static const size_t kRegExpCodeSize = 1024;
130 
131   // Load a number of characters at the given offset from the
132   // current position, into the current-character register.
133   void LoadCurrentCharacterUnchecked(int cp_offset, int character_count);
134 
135   // Check whether preemption has been requested.
136   void CheckPreemption();
137 
138   // Check whether we are exceeding the stack limit on the backtrack stack.
139   void CheckStackLimit();
140 
141 
142   // Generate a call to CheckStackGuardState.
143   void CallCheckStackGuardState(Register scratch);
144 
145   // The ebp-relative location of a regexp register.
146   MemOperand register_location(int register_index);
147 
148   // Register holding the current input position as negative offset from
149   // the end of the string.
current_input_offset()150   inline Register current_input_offset() { return t2; }
151 
152   // The register containing the current character after LoadCurrentCharacter.
current_character()153   inline Register current_character() { return t3; }
154 
155   // Register holding address of the end of the input string.
end_of_input_address()156   inline Register end_of_input_address() { return t6; }
157 
158   // Register holding the frame address. Local variables, parameters and
159   // regexp registers are addressed relative to this.
frame_pointer()160   inline Register frame_pointer() { return fp; }
161 
162   // The register containing the backtrack stack top. Provides a meaningful
163   // name to the register.
backtrack_stackpointer()164   inline Register backtrack_stackpointer() { return t4; }
165 
166   // Register holding pointer to the current code object.
code_pointer()167   inline Register code_pointer() { return t1; }
168 
169   // Byte size of chars in the string to match (decided by the Mode argument).
char_size()170   inline int char_size() { return static_cast<int>(mode_); }
171 
172   // Equivalent to a conditional branch to the label, unless the label
173   // is nullptr, in which case it is a conditional Backtrack.
174   void BranchOrBacktrack(Label* to,
175                          Condition condition,
176                          Register rs,
177                          const Operand& rt);
178 
179   // Call and return internally in the generated code in a way that
180   // is GC-safe (i.e., doesn't leave absolute code addresses on the stack)
181   inline void SafeCall(Label* to,
182                        Condition cond,
183                        Register rs,
184                        const Operand& rt);
185   inline void SafeReturn();
186   inline void SafeCallTarget(Label* name);
187 
188   // Pushes the value of a register on the backtrack stack. Decrements the
189   // stack pointer by a word size and stores the register's value there.
190   inline void Push(Register source);
191 
192   // Pops a value from the backtrack stack. Reads the word at the stack pointer
193   // and increments it by a word size.
194   inline void Pop(Register target);
195 
isolate()196   Isolate* isolate() const { return masm_->isolate(); }
197 
198   MacroAssembler* masm_;
199 
200   // Which mode to generate code for (Latin1 or UC16).
201   Mode mode_;
202 
203   // One greater than maximal register index actually used.
204   int num_registers_;
205 
206   // Number of registers to output at the end (the saved registers
207   // are always 0..num_saved_registers_-1).
208   int num_saved_registers_;
209 
210   // Labels used internally.
211   Label entry_label_;
212   Label start_label_;
213   Label success_label_;
214   Label backtrack_label_;
215   Label exit_label_;
216   Label check_preempt_label_;
217   Label stack_overflow_label_;
218   Label internal_failure_label_;
219 };
220 
221 #endif  // V8_INTERPRETED_REGEXP
222 
223 
224 }  // namespace internal
225 }  // namespace v8
226 
227 #endif  // V8_REGEXP_MIPS_REGEXP_MACRO_ASSEMBLER_MIPS_H_
228