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_X64_CODE_STUBS_X64_H_
6#define V8_X64_CODE_STUBS_X64_H_
7
8namespace v8 {
9namespace internal {
10
11
12void ArrayNativeCode(MacroAssembler* masm, Label* call_generic_code);
13
14
15class StringHelper : public AllStatic {
16 public:
17  // Compares two flat one-byte strings and returns result in rax.
18  static void GenerateCompareFlatOneByteStrings(
19      MacroAssembler* masm, Register left, Register right, Register scratch1,
20      Register scratch2, Register scratch3, Register scratch4);
21
22  // Compares two flat one-byte strings for equality and returns result in rax.
23  static void GenerateFlatOneByteStringEquals(MacroAssembler* masm,
24                                              Register left, Register right,
25                                              Register scratch1,
26                                              Register scratch2);
27
28 private:
29  static void GenerateOneByteCharsCompareLoop(
30      MacroAssembler* masm, Register left, Register right, Register length,
31      Register scratch, Label* chars_not_equal,
32      Label::Distance near_jump = Label::kFar);
33
34  DISALLOW_IMPLICIT_CONSTRUCTORS(StringHelper);
35};
36
37
38class NameDictionaryLookupStub: public PlatformCodeStub {
39 public:
40  enum LookupMode { POSITIVE_LOOKUP, NEGATIVE_LOOKUP };
41
42  NameDictionaryLookupStub(Isolate* isolate, Register dictionary,
43                           Register result, Register index, LookupMode mode)
44      : PlatformCodeStub(isolate) {
45    minor_key_ = DictionaryBits::encode(dictionary.code()) |
46                 ResultBits::encode(result.code()) |
47                 IndexBits::encode(index.code()) | LookupModeBits::encode(mode);
48  }
49
50  static void GenerateNegativeLookup(MacroAssembler* masm,
51                                     Label* miss,
52                                     Label* done,
53                                     Register properties,
54                                     Handle<Name> name,
55                                     Register r0);
56
57  bool SometimesSetsUpAFrame() override { return false; }
58
59 private:
60  static const int kInlinedProbes = 4;
61  static const int kTotalProbes = 20;
62
63  static const int kCapacityOffset =
64      NameDictionary::kHeaderSize +
65      NameDictionary::kCapacityIndex * kPointerSize;
66
67  static const int kElementsStartOffset =
68      NameDictionary::kHeaderSize +
69      NameDictionary::kElementsStartIndex * kPointerSize;
70
71  Register dictionary() const {
72    return Register::from_code(DictionaryBits::decode(minor_key_));
73  }
74
75  Register result() const {
76    return Register::from_code(ResultBits::decode(minor_key_));
77  }
78
79  Register index() const {
80    return Register::from_code(IndexBits::decode(minor_key_));
81  }
82
83  LookupMode mode() const { return LookupModeBits::decode(minor_key_); }
84
85  class DictionaryBits: public BitField<int, 0, 4> {};
86  class ResultBits: public BitField<int, 4, 4> {};
87  class IndexBits: public BitField<int, 8, 4> {};
88  class LookupModeBits: public BitField<LookupMode, 12, 1> {};
89
90  DEFINE_NULL_CALL_INTERFACE_DESCRIPTOR();
91  DEFINE_PLATFORM_CODE_STUB(NameDictionaryLookup, PlatformCodeStub);
92};
93
94
95class RecordWriteStub: public PlatformCodeStub {
96 public:
97  RecordWriteStub(Isolate* isolate, Register object, Register value,
98                  Register address, RememberedSetAction remembered_set_action,
99                  SaveFPRegsMode fp_mode)
100      : PlatformCodeStub(isolate),
101        regs_(object,   // An input reg.
102              address,  // An input reg.
103              value) {  // One scratch reg.
104    minor_key_ = ObjectBits::encode(object.code()) |
105                 ValueBits::encode(value.code()) |
106                 AddressBits::encode(address.code()) |
107                 RememberedSetActionBits::encode(remembered_set_action) |
108                 SaveFPRegsModeBits::encode(fp_mode);
109  }
110
111  RecordWriteStub(uint32_t key, Isolate* isolate)
112      : PlatformCodeStub(key, isolate), regs_(object(), address(), value()) {}
113
114  enum Mode {
115    STORE_BUFFER_ONLY,
116    INCREMENTAL,
117    INCREMENTAL_COMPACTION
118  };
119
120  bool SometimesSetsUpAFrame() override { return false; }
121
122  static const byte kTwoByteNopInstruction = 0x3c;  // Cmpb al, #imm8.
123  static const byte kTwoByteJumpInstruction = 0xeb;  // Jmp #imm8.
124
125  static const byte kFiveByteNopInstruction = 0x3d;  // Cmpl eax, #imm32.
126  static const byte kFiveByteJumpInstruction = 0xe9;  // Jmp #imm32.
127
128  static Mode GetMode(Code* stub) {
129    byte first_instruction = stub->instruction_start()[0];
130    byte second_instruction = stub->instruction_start()[2];
131
132    if (first_instruction == kTwoByteJumpInstruction) {
133      return INCREMENTAL;
134    }
135
136    DCHECK(first_instruction == kTwoByteNopInstruction);
137
138    if (second_instruction == kFiveByteJumpInstruction) {
139      return INCREMENTAL_COMPACTION;
140    }
141
142    DCHECK(second_instruction == kFiveByteNopInstruction);
143
144    return STORE_BUFFER_ONLY;
145  }
146
147  static void Patch(Code* stub, Mode mode) {
148    switch (mode) {
149      case STORE_BUFFER_ONLY:
150        DCHECK(GetMode(stub) == INCREMENTAL ||
151               GetMode(stub) == INCREMENTAL_COMPACTION);
152        stub->instruction_start()[0] = kTwoByteNopInstruction;
153        stub->instruction_start()[2] = kFiveByteNopInstruction;
154        break;
155      case INCREMENTAL:
156        DCHECK(GetMode(stub) == STORE_BUFFER_ONLY);
157        stub->instruction_start()[0] = kTwoByteJumpInstruction;
158        break;
159      case INCREMENTAL_COMPACTION:
160        DCHECK(GetMode(stub) == STORE_BUFFER_ONLY);
161        stub->instruction_start()[0] = kTwoByteNopInstruction;
162        stub->instruction_start()[2] = kFiveByteJumpInstruction;
163        break;
164    }
165    DCHECK(GetMode(stub) == mode);
166    Assembler::FlushICache(stub->GetIsolate(), stub->instruction_start(), 7);
167  }
168
169  DEFINE_NULL_CALL_INTERFACE_DESCRIPTOR();
170
171 private:
172  // This is a helper class for freeing up 3 scratch registers, where the third
173  // is always rcx (needed for shift operations).  The input is two registers
174  // that must be preserved and one scratch register provided by the caller.
175  class RegisterAllocation {
176   public:
177    RegisterAllocation(Register object,
178                       Register address,
179                       Register scratch0)
180        : object_orig_(object),
181          address_orig_(address),
182          scratch0_orig_(scratch0),
183          object_(object),
184          address_(address),
185          scratch0_(scratch0) {
186      DCHECK(!AreAliased(scratch0, object, address, no_reg));
187      scratch1_ = GetRegThatIsNotRcxOr(object_, address_, scratch0_);
188      if (scratch0.is(rcx)) {
189        scratch0_ = GetRegThatIsNotRcxOr(object_, address_, scratch1_);
190      }
191      if (object.is(rcx)) {
192        object_ = GetRegThatIsNotRcxOr(address_, scratch0_, scratch1_);
193      }
194      if (address.is(rcx)) {
195        address_ = GetRegThatIsNotRcxOr(object_, scratch0_, scratch1_);
196      }
197      DCHECK(!AreAliased(scratch0_, object_, address_, rcx));
198    }
199
200    void Save(MacroAssembler* masm) {
201      DCHECK(!address_orig_.is(object_));
202      DCHECK(object_.is(object_orig_) || address_.is(address_orig_));
203      DCHECK(!AreAliased(object_, address_, scratch1_, scratch0_));
204      DCHECK(!AreAliased(object_orig_, address_, scratch1_, scratch0_));
205      DCHECK(!AreAliased(object_, address_orig_, scratch1_, scratch0_));
206      // We don't have to save scratch0_orig_ because it was given to us as
207      // a scratch register.  But if we had to switch to a different reg then
208      // we should save the new scratch0_.
209      if (!scratch0_.is(scratch0_orig_)) masm->Push(scratch0_);
210      if (!rcx.is(scratch0_orig_) &&
211          !rcx.is(object_orig_) &&
212          !rcx.is(address_orig_)) {
213        masm->Push(rcx);
214      }
215      masm->Push(scratch1_);
216      if (!address_.is(address_orig_)) {
217        masm->Push(address_);
218        masm->movp(address_, address_orig_);
219      }
220      if (!object_.is(object_orig_)) {
221        masm->Push(object_);
222        masm->movp(object_, object_orig_);
223      }
224    }
225
226    void Restore(MacroAssembler* masm) {
227      // These will have been preserved the entire time, so we just need to move
228      // them back.  Only in one case is the orig_ reg different from the plain
229      // one, since only one of them can alias with rcx.
230      if (!object_.is(object_orig_)) {
231        masm->movp(object_orig_, object_);
232        masm->Pop(object_);
233      }
234      if (!address_.is(address_orig_)) {
235        masm->movp(address_orig_, address_);
236        masm->Pop(address_);
237      }
238      masm->Pop(scratch1_);
239      if (!rcx.is(scratch0_orig_) &&
240          !rcx.is(object_orig_) &&
241          !rcx.is(address_orig_)) {
242        masm->Pop(rcx);
243      }
244      if (!scratch0_.is(scratch0_orig_)) masm->Pop(scratch0_);
245    }
246
247    // If we have to call into C then we need to save and restore all caller-
248    // saved registers that were not already preserved.
249
250    // The three scratch registers (incl. rcx) will be restored by other means
251    // so we don't bother pushing them here.  Rbx, rbp and r12-15 are callee
252    // save and don't need to be preserved.
253    void SaveCallerSaveRegisters(MacroAssembler* masm, SaveFPRegsMode mode) {
254      masm->PushCallerSaved(mode, scratch0_, scratch1_, rcx);
255    }
256
257    inline void RestoreCallerSaveRegisters(MacroAssembler*masm,
258                                           SaveFPRegsMode mode) {
259      masm->PopCallerSaved(mode, scratch0_, scratch1_, rcx);
260    }
261
262    inline Register object() { return object_; }
263    inline Register address() { return address_; }
264    inline Register scratch0() { return scratch0_; }
265    inline Register scratch1() { return scratch1_; }
266
267   private:
268    Register object_orig_;
269    Register address_orig_;
270    Register scratch0_orig_;
271    Register object_;
272    Register address_;
273    Register scratch0_;
274    Register scratch1_;
275    // Third scratch register is always rcx.
276
277    Register GetRegThatIsNotRcxOr(Register r1,
278                                  Register r2,
279                                  Register r3) {
280      for (int i = 0; i < Register::kNumRegisters; i++) {
281        if (RegisterConfiguration::Crankshaft()->IsAllocatableGeneralCode(i)) {
282          Register candidate = Register::from_code(i);
283          if (candidate.is(rcx)) continue;
284          if (candidate.is(r1)) continue;
285          if (candidate.is(r2)) continue;
286          if (candidate.is(r3)) continue;
287          return candidate;
288        }
289      }
290      UNREACHABLE();
291      return no_reg;
292    }
293    friend class RecordWriteStub;
294  };
295
296  enum OnNoNeedToInformIncrementalMarker {
297    kReturnOnNoNeedToInformIncrementalMarker,
298    kUpdateRememberedSetOnNoNeedToInformIncrementalMarker
299  };
300
301  Major MajorKey() const final { return RecordWrite; }
302
303  void Generate(MacroAssembler* masm) override;
304  void GenerateIncremental(MacroAssembler* masm, Mode mode);
305  void CheckNeedsToInformIncrementalMarker(
306      MacroAssembler* masm,
307      OnNoNeedToInformIncrementalMarker on_no_need,
308      Mode mode);
309  void InformIncrementalMarker(MacroAssembler* masm);
310
311  void Activate(Code* code) override;
312
313  Register object() const {
314    return Register::from_code(ObjectBits::decode(minor_key_));
315  }
316
317  Register value() const {
318    return Register::from_code(ValueBits::decode(minor_key_));
319  }
320
321  Register address() const {
322    return Register::from_code(AddressBits::decode(minor_key_));
323  }
324
325  RememberedSetAction remembered_set_action() const {
326    return RememberedSetActionBits::decode(minor_key_);
327  }
328
329  SaveFPRegsMode save_fp_regs_mode() const {
330    return SaveFPRegsModeBits::decode(minor_key_);
331  }
332
333  class ObjectBits: public BitField<int, 0, 4> {};
334  class ValueBits: public BitField<int, 4, 4> {};
335  class AddressBits: public BitField<int, 8, 4> {};
336  class RememberedSetActionBits: public BitField<RememberedSetAction, 12, 1> {};
337  class SaveFPRegsModeBits: public BitField<SaveFPRegsMode, 13, 1> {};
338
339  Label slow_;
340  RegisterAllocation regs_;
341
342  DISALLOW_COPY_AND_ASSIGN(RecordWriteStub);
343};
344
345
346}  // namespace internal
347}  // namespace v8
348
349#endif  // V8_X64_CODE_STUBS_X64_H_
350