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 
6 #ifndef V8_MIPS_REGEXP_MACRO_ASSEMBLER_MIPS_H_
7 #define V8_MIPS_REGEXP_MACRO_ASSEMBLER_MIPS_H_
8 
9 #include "src/macro-assembler.h"
10 #include "src/mips/assembler-mips-inl.h"
11 #include "src/mips/assembler-mips.h"
12 #include "src/mips/macro-assembler-mips.h"
13 
14 namespace v8 {
15 namespace internal {
16 
17 #ifndef V8_INTERPRETED_REGEXP
18 class RegExpMacroAssemblerMIPS: public NativeRegExpMacroAssembler {
19  public:
20   RegExpMacroAssemblerMIPS(Mode mode, int registers_to_save, Zone* zone);
21   virtual ~RegExpMacroAssemblerMIPS();
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   virtual bool CanReadUnaligned();
88 
89   // Called from RegExp if the stack-guard is triggered.
90   // If the code object is relocated, the return address is fixed before
91   // returning.
92   static int CheckStackGuardState(Address* return_address,
93                                   Code* re_code,
94                                   Address re_frame);
95 
96  private:
97   // Offsets from frame_pointer() of function parameters and stored registers.
98   static const int kFramePointer = 0;
99 
100   // Above the frame pointer - Stored registers and stack passed parameters.
101   // Registers s0 to s7, fp, and ra.
102   static const int kStoredRegisters = kFramePointer;
103   // Return address (stored from link register, read into pc on return).
104   static const int kReturnAddress = kStoredRegisters + 9 * kPointerSize;
105   static const int kSecondaryReturnAddress = kReturnAddress + kPointerSize;
106   // Stack frame header.
107   static const int kStackFrameHeader = kReturnAddress + kPointerSize;
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 kInputStartMinusOne = kSuccessfulCaptures - kPointerSize;
125   // First register address. Following registers are below it on the stack.
126   static const int kRegisterZero = kInputStartMinusOne - 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 NULL, 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 v8::internal
225 
226 #endif  // V8_MIPS_REGEXP_MACRO_ASSEMBLER_MIPS_H_
227