1 // Copyright 2014 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_PPC_REGEXP_MACRO_ASSEMBLER_PPC_H_
6 #define V8_REGEXP_PPC_REGEXP_MACRO_ASSEMBLER_PPC_H_
7 
8 #include "src/codegen/macro-assembler.h"
9 #include "src/regexp/regexp-macro-assembler.h"
10 
11 namespace v8 {
12 namespace internal {
13 
14 class V8_EXPORT_PRIVATE RegExpMacroAssemblerPPC
15     : public NativeRegExpMacroAssembler {
16  public:
17   RegExpMacroAssemblerPPC(Isolate* isolate, Zone* zone, Mode mode,
18                           int registers_to_save);
19   virtual ~RegExpMacroAssemblerPPC();
20   virtual int stack_limit_slack();
21   virtual void AdvanceCurrentPosition(int by);
22   virtual void AdvanceRegister(int reg, int by);
23   virtual void Backtrack();
24   virtual void Bind(Label* label);
25   virtual void CheckAtStart(int cp_offset, Label* on_at_start);
26   virtual void CheckCharacter(unsigned c, Label* on_equal);
27   virtual void CheckCharacterAfterAnd(unsigned c, unsigned mask,
28                                       Label* on_equal);
29   virtual void CheckCharacterGT(base::uc16 limit, Label* on_greater);
30   virtual void CheckCharacterLT(base::uc16 limit, Label* on_less);
31   // A "greedy loop" is a loop that is both greedy and with a simple
32   // body. It has a particularly simple implementation.
33   virtual void CheckGreedyLoop(Label* on_tos_equals_current_position);
34   virtual void CheckNotAtStart(int cp_offset, Label* on_not_at_start);
35   virtual void CheckNotBackReference(int start_reg, bool read_backward,
36                                      Label* on_no_match);
37   virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
38                                                bool read_backward, bool unicode,
39                                                Label* on_no_match);
40   virtual void CheckNotCharacter(unsigned c, Label* on_not_equal);
41   virtual void CheckNotCharacterAfterAnd(unsigned c, unsigned mask,
42                                          Label* on_not_equal);
43   virtual void CheckNotCharacterAfterMinusAnd(base::uc16 c, base::uc16 minus,
44                                               base::uc16 mask,
45                                               Label* on_not_equal);
46   virtual void CheckCharacterInRange(base::uc16 from, base::uc16 to,
47                                      Label* on_in_range);
48   virtual void CheckCharacterNotInRange(base::uc16 from, base::uc16 to,
49                                         Label* on_not_in_range);
50   virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set);
51 
52   // Checks whether the given offset from the current position is before
53   // the end of the string.
54   virtual void CheckPosition(int cp_offset, Label* on_outside_input);
55   virtual bool CheckSpecialCharacterClass(base::uc16 type, Label* on_no_match);
56   virtual void Fail();
57   virtual Handle<HeapObject> GetCode(Handle<String> source);
58   virtual void GoTo(Label* label);
59   virtual void IfRegisterGE(int reg, int comparand, Label* if_ge);
60   virtual void IfRegisterLT(int reg, int comparand, Label* if_lt);
61   virtual void IfRegisterEqPos(int reg, Label* if_eq);
62   virtual IrregexpImplementation Implementation();
63   virtual void LoadCurrentCharacterUnchecked(int cp_offset,
64                                              int character_count);
65   virtual void PopCurrentPosition();
66   virtual void PopRegister(int register_index);
67   virtual void PushBacktrack(Label* label);
68   virtual void PushCurrentPosition();
69   virtual void PushRegister(int register_index,
70                             StackCheckFlag check_stack_limit);
71   virtual void ReadCurrentPositionFromRegister(int reg);
72   virtual void ReadStackPointerFromRegister(int reg);
73   virtual void SetCurrentPositionFromEnd(int by);
74   virtual void SetRegister(int register_index, int to);
75   virtual bool Succeed();
76   virtual void WriteCurrentPositionToRegister(int reg, int cp_offset);
77   virtual void ClearRegisters(int reg_from, int reg_to);
78   virtual void WriteStackPointerToRegister(int reg);
79 
80   // Called from RegExp if the stack-guard is triggered.
81   // If the code object is relocated, the return address is fixed before
82   // returning.
83   // {raw_code} is an Address because this is called via ExternalReference.
84   static int CheckStackGuardState(Address* return_address, Address raw_code,
85                                   Address re_frame);
86 
87  private:
88   // Offsets from frame_pointer() of function parameters and stored registers.
89   static const int kFramePointer = 0;
90 
91   // Above the frame pointer - Stored registers and stack passed parameters.
92   static const int kStoredRegisters = kFramePointer;
93   // Return address (stored from link register, read into pc on return).
94   static const int kReturnAddress = kStoredRegisters + 7 * kSystemPointerSize;
95   static const int kCallerFrame = kReturnAddress + kSystemPointerSize;
96 
97   // Below the frame pointer.
98   // Register parameters stored by setup code.
99   static const int kIsolate = kFramePointer - kSystemPointerSize;
100   static const int kDirectCall = kIsolate - kSystemPointerSize;
101   static const int kNumOutputRegisters = kDirectCall - kSystemPointerSize;
102   static const int kRegisterOutput = kNumOutputRegisters - kSystemPointerSize;
103   static const int kInputEnd = kRegisterOutput - kSystemPointerSize;
104   static const int kInputStart = kInputEnd - kSystemPointerSize;
105   static const int kStartIndex = kInputStart - kSystemPointerSize;
106   static const int kInputString = kStartIndex - kSystemPointerSize;
107   // When adding local variables remember to push space for them in
108   // the frame in GetCode.
109   static const int kSuccessfulCaptures = kInputString - kSystemPointerSize;
110   static const int kStringStartMinusOne =
111       kSuccessfulCaptures - kSystemPointerSize;
112   static const int kBacktrackCount = kStringStartMinusOne - kSystemPointerSize;
113   // Stores the initial value of the regexp stack pointer in a
114   // position-independent representation (in case the regexp stack grows and
115   // thus moves).
116   static const int kRegExpStackBasePointer =
117       kBacktrackCount - kSystemPointerSize;
118 
119   // First register address. Following registers are below it on the stack.
120   static const int kRegisterZero = kRegExpStackBasePointer - kSystemPointerSize;
121 
122   // Initial size of code buffer.
123   static const int kRegExpCodeSize = 1024;
124 
125   // Check whether preemption has been requested.
126   void CheckPreemption();
127 
128   // Check whether we are exceeding the stack limit on the backtrack stack.
129   void CheckStackLimit();
130 
131 
132   // Generate a call to CheckStackGuardState.
133   void CallCheckStackGuardState(Register scratch);
134 
135   // The ebp-relative location of a regexp register.
136   MemOperand register_location(int register_index);
137 
138   // Register holding the current input position as negative offset from
139   // the end of the string.
current_input_offset()140   static constexpr Register current_input_offset() { return r27; }
141 
142   // The register containing the current character after LoadCurrentCharacter.
current_character()143   static constexpr Register current_character() { return r28; }
144 
145   // Register holding address of the end of the input string.
end_of_input_address()146   static constexpr Register end_of_input_address() { return r30; }
147 
148   // Register holding the frame address. Local variables, parameters and
149   // regexp registers are addressed relative to this.
frame_pointer()150   static constexpr Register frame_pointer() { return fp; }
151 
152   // The register containing the backtrack stack top. Provides a meaningful
153   // name to the register.
backtrack_stackpointer()154   static constexpr Register backtrack_stackpointer() { return r29; }
155 
156   // Register holding pointer to the current code object.
code_pointer()157   static constexpr Register code_pointer() { return r26; }
158 
159   // Byte size of chars in the string to match (decided by the Mode argument)
char_size()160   inline int char_size() const { return static_cast<int>(mode_); }
161 
162   // Equivalent to a conditional branch to the label, unless the label
163   // is nullptr, in which case it is a conditional Backtrack.
164   void BranchOrBacktrack(Condition condition, Label* to, CRegister cr = cr7);
165 
166   // Call and return internally in the generated code in a way that
167   // is GC-safe (i.e., doesn't leave absolute code addresses on the stack)
168   inline void SafeCall(Label* to, Condition cond = al, CRegister cr = cr7);
169   inline void SafeReturn();
170   inline void SafeCallTarget(Label* name);
171 
172   // Pushes the value of a register on the backtrack stack. Decrements the
173   // stack pointer by a word size and stores the register's value there.
174   inline void Push(Register source);
175 
176   // Pops a value from the backtrack stack. Reads the word at the stack pointer
177   // and increments it by a word size.
178   inline void Pop(Register target);
179 
180   void LoadRegExpStackPointerFromMemory(Register dst);
181   void StoreRegExpStackPointerToMemory(Register src, Register scratch);
182   void PushRegExpBasePointer(Register stack_pointer, Register scratch);
183   void PopRegExpBasePointer(Register stack_pointer_out, Register scratch);
184 
isolate()185   Isolate* isolate() const { return masm_->isolate(); }
186 
187   const std::unique_ptr<MacroAssembler> masm_;
188   const NoRootArrayScope no_root_array_scope_;
189 
190   // Which mode to generate code for (Latin1 or UC16).
191   const Mode mode_;
192 
193   // One greater than maximal register index actually used.
194   int num_registers_;
195 
196   // Number of registers to output at the end (the saved registers
197   // are always 0..num_saved_registers_-1)
198   const int num_saved_registers_;
199 
200   // Labels used internally.
201   Label entry_label_;
202   Label start_label_;
203   Label success_label_;
204   Label backtrack_label_;
205   Label exit_label_;
206   Label check_preempt_label_;
207   Label stack_overflow_label_;
208   Label internal_failure_label_;
209   Label fallback_label_;
210 };
211 
212 // Set of non-volatile registers saved/restored by generated regexp code.
213 const RegList kRegExpCalleeSaved =
214     1 << 25 | 1 << 26 | 1 << 27 | 1 << 28 | 1 << 29 | 1 << 30 | 1 << 31;
215 
216 }  // namespace internal
217 }  // namespace v8
218 
219 #endif  // V8_REGEXP_PPC_REGEXP_MACRO_ASSEMBLER_PPC_H_
220