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/codegen/macro-assembler.h"
9#include "src/regexp/regexp-macro-assembler.h"
10#include "src/zone/zone-chunk-list.h"
11
12namespace v8 {
13namespace internal {
14
15class V8_EXPORT_PRIVATE RegExpMacroAssemblerX64
16    : public NativeRegExpMacroAssembler {
17 public:
18  RegExpMacroAssemblerX64(Isolate* isolate, Zone* zone, Mode mode,
19                          int registers_to_save);
20  ~RegExpMacroAssemblerX64() override;
21  int stack_limit_slack() override;
22  void AdvanceCurrentPosition(int by) override;
23  void AdvanceRegister(int reg, int by) override;
24  void Backtrack() override;
25  void Bind(Label* label) override;
26  void CheckAtStart(int cp_offset, Label* on_at_start) override;
27  void CheckCharacter(uint32_t c, Label* on_equal) override;
28  void CheckCharacterAfterAnd(uint32_t c, uint32_t mask,
29                              Label* on_equal) override;
30  void CheckCharacterGT(base::uc16 limit, Label* on_greater) override;
31  void CheckCharacterLT(base::uc16 limit, Label* on_less) override;
32  // A "greedy loop" is a loop that is both greedy and with a simple
33  // body. It has a particularly simple implementation.
34  void CheckGreedyLoop(Label* on_tos_equals_current_position) override;
35  void CheckNotAtStart(int cp_offset, Label* on_not_at_start) override;
36  void CheckNotBackReference(int start_reg, bool read_backward,
37                             Label* on_no_match) override;
38  void CheckNotBackReferenceIgnoreCase(int start_reg, bool read_backward,
39                                       bool unicode,
40                                       Label* on_no_match) override;
41  void CheckNotCharacter(uint32_t c, Label* on_not_equal) override;
42  void CheckNotCharacterAfterAnd(uint32_t c, uint32_t mask,
43                                 Label* on_not_equal) override;
44  void CheckNotCharacterAfterMinusAnd(base::uc16 c, base::uc16 minus,
45                                      base::uc16 mask,
46                                      Label* on_not_equal) override;
47  void CheckCharacterInRange(base::uc16 from, base::uc16 to,
48                             Label* on_in_range) override;
49  void CheckCharacterNotInRange(base::uc16 from, base::uc16 to,
50                                Label* on_not_in_range) override;
51  bool CheckCharacterInRangeArray(const ZoneList<CharacterRange>* ranges,
52                                  Label* on_in_range) override;
53  bool CheckCharacterNotInRangeArray(const ZoneList<CharacterRange>* ranges,
54                                     Label* on_not_in_range) override;
55  void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set) override;
56
57  // Checks whether the given offset from the current position is before
58  // the end of the string.
59  void CheckPosition(int cp_offset, Label* on_outside_input) override;
60  bool CheckSpecialCharacterClass(StandardCharacterSet type,
61                                  Label* on_no_match) override;
62  void Fail() override;
63  Handle<HeapObject> GetCode(Handle<String> source) override;
64  void GoTo(Label* label) override;
65  void IfRegisterGE(int reg, int comparand, Label* if_ge) override;
66  void IfRegisterLT(int reg, int comparand, Label* if_lt) override;
67  void IfRegisterEqPos(int reg, Label* if_eq) override;
68  IrregexpImplementation Implementation() override;
69  void LoadCurrentCharacterUnchecked(int cp_offset,
70                                     int character_count) override;
71  void PopCurrentPosition() override;
72  void PopRegister(int register_index) override;
73  void PushBacktrack(Label* label) override;
74  void PushCurrentPosition() override;
75  void PushRegister(int register_index,
76                    StackCheckFlag check_stack_limit) override;
77  void ReadCurrentPositionFromRegister(int reg) override;
78  void ReadStackPointerFromRegister(int reg) override;
79  void SetCurrentPositionFromEnd(int by) override;
80  void SetRegister(int register_index, int to) override;
81  bool Succeed() override;
82  void WriteCurrentPositionToRegister(int reg, int cp_offset) override;
83  void ClearRegisters(int reg_from, int reg_to) override;
84  void WriteStackPointerToRegister(int reg) override;
85
86  // Called from RegExp if the stack-guard is triggered.
87  // If the code object is relocated, the return address is fixed before
88  // returning.
89  // {raw_code} is an Address because this is called via ExternalReference.
90  static int CheckStackGuardState(Address* return_address, Address raw_code,
91                                  Address re_frame);
92
93 private:
94  // Offsets from rbp of function parameters and stored registers.
95  static const int kFramePointer = 0;
96  // Above the frame pointer - function parameters and return address.
97  static const int kReturn_eip = kFramePointer + kSystemPointerSize;
98  static const int kFrameAlign = kReturn_eip + kSystemPointerSize;
99
100#ifdef V8_TARGET_OS_WIN
101  // Parameters (first four passed as registers, but with room on stack).
102  // In Microsoft 64-bit Calling Convention, there is room on the callers
103  // stack (before the return address) to spill parameter registers. We
104  // use this space to store the register passed parameters.
105  static const int kInputString = kFrameAlign;
106  // StartIndex is passed as 32 bit int.
107  static const int kStartIndex = kInputString + kSystemPointerSize;
108  static const int kInputStart = kStartIndex + kSystemPointerSize;
109  static const int kInputEnd = kInputStart + kSystemPointerSize;
110  static const int kRegisterOutput = kInputEnd + kSystemPointerSize;
111  // For the case of global regular expression, we have room to store at least
112  // one set of capture results.  For the case of non-global regexp, we ignore
113  // this value. NumOutputRegisters is passed as 32-bit value.  The upper
114  // 32 bit of this 64-bit stack slot may contain garbage.
115  static const int kNumOutputRegisters = kRegisterOutput + kSystemPointerSize;
116  // DirectCall is passed as 32 bit int (values 0 or 1).
117  static const int kDirectCall = kNumOutputRegisters + kSystemPointerSize;
118  static const int kIsolate = kDirectCall + kSystemPointerSize;
119#else
120  // In AMD64 ABI Calling Convention, the first six integer parameters
121  // are passed as registers, and caller must allocate space on the stack
122  // if it wants them stored. We push the parameters after the frame pointer.
123  static const int kInputString = kFramePointer - kSystemPointerSize;
124  static const int kStartIndex = kInputString - kSystemPointerSize;
125  static const int kInputStart = kStartIndex - kSystemPointerSize;
126  static const int kInputEnd = kInputStart - kSystemPointerSize;
127  static const int kRegisterOutput = kInputEnd - kSystemPointerSize;
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.
131  static const int kNumOutputRegisters = kRegisterOutput - kSystemPointerSize;
132
133  static const int kDirectCall = kFrameAlign;
134  static const int kIsolate = kDirectCall + kSystemPointerSize;
135#endif
136
137  // We push callee-save registers that we use after the frame pointer (and
138  // after the parameters).
139#ifdef V8_TARGET_OS_WIN
140  static const int kBackup_rsi = kFramePointer - kSystemPointerSize;
141  static const int kBackup_rdi = kBackup_rsi - kSystemPointerSize;
142  static const int kBackup_rbx = kBackup_rdi - kSystemPointerSize;
143  static const int kNumCalleeSaveRegisters = 3;
144  static const int kLastCalleeSaveRegister = kBackup_rbx;
145#else
146  static const int kBackup_rbx = kNumOutputRegisters - kSystemPointerSize;
147  static const int kNumCalleeSaveRegisters = 1;
148  static const int kLastCalleeSaveRegister = kBackup_rbx;
149#endif
150
151  // When adding local variables remember to push space for them in
152  // the frame in GetCode.
153  static const int kSuccessfulCaptures =
154      kLastCalleeSaveRegister - kSystemPointerSize;
155  static const int kStringStartMinusOne =
156      kSuccessfulCaptures - kSystemPointerSize;
157  static const int kBacktrackCount = kStringStartMinusOne - kSystemPointerSize;
158  // Stores the initial value of the regexp stack pointer in a
159  // position-independent representation (in case the regexp stack grows and
160  // thus moves).
161  static const int kRegExpStackBasePointer =
162      kBacktrackCount - kSystemPointerSize;
163
164  // First register address. Following registers are below it on the stack.
165  static const int kRegisterZero = kRegExpStackBasePointer - kSystemPointerSize;
166
167  // Initial size of code buffer.
168  static const int kRegExpCodeSize = 1024;
169
170  void PushCallerSavedRegisters();
171  void PopCallerSavedRegisters();
172
173  // Check whether preemption has been requested.
174  void CheckPreemption();
175
176  // Check whether we are exceeding the stack limit on the backtrack stack.
177  void CheckStackLimit();
178
179  void CallCheckStackGuardState();
180  void CallIsCharacterInRangeArray(const ZoneList<CharacterRange>* ranges);
181
182  // The rbp-relative location of a regexp register.
183  Operand register_location(int register_index);
184
185  // The register containing the current character after LoadCurrentCharacter.
186  static constexpr Register current_character() { return rdx; }
187
188  // The register containing the backtrack stack top. Provides a meaningful
189  // name to the register.
190  static constexpr Register backtrack_stackpointer() { return rcx; }
191
192  // The registers containing a self pointer to this code's Code object.
193  static constexpr Register code_object_pointer() { return r8; }
194
195  // Byte size of chars in the string to match (decided by the Mode argument)
196  inline int char_size() { return static_cast<int>(mode_); }
197
198  // Equivalent to a conditional branch to the label, unless the label
199  // is nullptr, in which case it is a conditional Backtrack.
200  void BranchOrBacktrack(Condition condition, Label* to);
201
202  void MarkPositionForCodeRelativeFixup() {
203    code_relative_fixup_positions_.push_back(masm_.pc_offset());
204  }
205
206  void FixupCodeRelativePositions();
207
208  // Call and return internally in the generated code in a way that
209  // is GC-safe (i.e., doesn't leave absolute code addresses on the stack)
210  inline void SafeCall(Label* to);
211  inline void SafeCallTarget(Label* label);
212  inline void SafeReturn();
213
214  // Pushes the value of a register on the backtrack stack. Decrements the
215  // stack pointer (rcx) by a word size and stores the register's value there.
216  inline void Push(Register source);
217
218  // Pushes a value on the backtrack stack. Decrements the stack pointer (rcx)
219  // by a word size and stores the value there.
220  inline void Push(Immediate value);
221
222  // Pushes the Code object relative offset of a label on the backtrack stack
223  // (i.e., a backtrack target). Decrements the stack pointer (rcx)
224  // by a word size and stores the value there.
225  inline void Push(Label* label);
226
227  // Pops a value from the backtrack stack. Reads the word at the stack pointer
228  // (rcx) and increments it by a word size.
229  inline void Pop(Register target);
230
231  // Drops the top value from the backtrack stack without reading it.
232  // Increments the stack pointer (rcx) by a word size.
233  inline void Drop();
234
235  void LoadRegExpStackPointerFromMemory(Register dst);
236  void StoreRegExpStackPointerToMemory(Register src, Register scratch);
237  void PushRegExpBasePointer(Register scratch_pointer, Register scratch);
238  void PopRegExpBasePointer(Register scratch_pointer_out, Register scratch);
239
240  inline void ReadPositionFromRegister(Register dst, int reg);
241
242  Isolate* isolate() const { return masm_.isolate(); }
243
244  MacroAssembler masm_;
245
246  // On x64, there is no reason to keep the kRootRegister uninitialized; we
247  // could easily use it by 1. initializing it and 2. storing/restoring it
248  // as callee-save on entry/exit.
249  // But: on other platforms, specifically ia32, it would be tricky to enable
250  // the kRootRegister since it's currently used for other purposes. Thus, for
251  // consistency, we also keep it uninitialized here.
252  const NoRootArrayScope no_root_array_scope_;
253
254  ZoneChunkList<int> code_relative_fixup_positions_;
255
256  // Which mode to generate code for (LATIN1 or UC16).
257  const Mode mode_;
258
259  // One greater than maximal register index actually used.
260  int num_registers_;
261
262  // Number of registers to output at the end (the saved registers
263  // are always 0..num_saved_registers_-1)
264  const int num_saved_registers_;
265
266  // Labels used internally.
267  Label entry_label_;
268  Label start_label_;
269  Label success_label_;
270  Label backtrack_label_;
271  Label exit_label_;
272  Label check_preempt_label_;
273  Label stack_overflow_label_;
274  Label fallback_label_;
275};
276
277}  // namespace internal
278}  // namespace v8
279
280#endif  // V8_REGEXP_X64_REGEXP_MACRO_ASSEMBLER_X64_H_
281