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_IA32_CODE_STUBS_IA32_H_
6#define V8_IA32_CODE_STUBS_IA32_H_
7
8namespace v8 {
9namespace internal {
10
11
12void ArrayNativeCode(MacroAssembler* masm,
13                     bool construct_call,
14                     Label* call_generic_code);
15
16
17class StringHelper : public AllStatic {
18 public:
19  // Generate code for copying characters using the rep movs instruction.
20  // Copies ecx characters from esi to edi. Copying of overlapping regions is
21  // not supported.
22  static void GenerateCopyCharacters(MacroAssembler* masm,
23                                     Register dest,
24                                     Register src,
25                                     Register count,
26                                     Register scratch,
27                                     String::Encoding encoding);
28
29  // Compares two flat one byte strings and returns result in eax.
30  static void GenerateCompareFlatOneByteStrings(MacroAssembler* masm,
31                                                Register left, Register right,
32                                                Register scratch1,
33                                                Register scratch2,
34                                                Register scratch3);
35
36  // Compares two flat one byte strings for equality and returns result in eax.
37  static void GenerateFlatOneByteStringEquals(MacroAssembler* masm,
38                                              Register left, Register right,
39                                              Register scratch1,
40                                              Register scratch2);
41
42 private:
43  static void GenerateOneByteCharsCompareLoop(
44      MacroAssembler* masm, Register left, Register right, Register length,
45      Register scratch, Label* chars_not_equal,
46      Label::Distance chars_not_equal_near = Label::kFar);
47
48  DISALLOW_IMPLICIT_CONSTRUCTORS(StringHelper);
49};
50
51
52class NameDictionaryLookupStub: public PlatformCodeStub {
53 public:
54  enum LookupMode { POSITIVE_LOOKUP, NEGATIVE_LOOKUP };
55
56  NameDictionaryLookupStub(Isolate* isolate, Register dictionary,
57                           Register result, Register index, LookupMode mode)
58      : PlatformCodeStub(isolate) {
59    minor_key_ = DictionaryBits::encode(dictionary.code()) |
60                 ResultBits::encode(result.code()) |
61                 IndexBits::encode(index.code()) | LookupModeBits::encode(mode);
62  }
63
64  static void GenerateNegativeLookup(MacroAssembler* masm,
65                                     Label* miss,
66                                     Label* done,
67                                     Register properties,
68                                     Handle<Name> name,
69                                     Register r0);
70
71  static void GeneratePositiveLookup(MacroAssembler* masm,
72                                     Label* miss,
73                                     Label* done,
74                                     Register elements,
75                                     Register name,
76                                     Register r0,
77                                     Register r1);
78
79  virtual bool SometimesSetsUpAFrame() { return false; }
80
81 private:
82  static const int kInlinedProbes = 4;
83  static const int kTotalProbes = 20;
84
85  static const int kCapacityOffset =
86      NameDictionary::kHeaderSize +
87      NameDictionary::kCapacityIndex * kPointerSize;
88
89  static const int kElementsStartOffset =
90      NameDictionary::kHeaderSize +
91      NameDictionary::kElementsStartIndex * kPointerSize;
92
93  Register dictionary() const {
94    return Register::from_code(DictionaryBits::decode(minor_key_));
95  }
96
97  Register result() const {
98    return Register::from_code(ResultBits::decode(minor_key_));
99  }
100
101  Register index() const {
102    return Register::from_code(IndexBits::decode(minor_key_));
103  }
104
105  LookupMode mode() const { return LookupModeBits::decode(minor_key_); }
106
107  class DictionaryBits: public BitField<int, 0, 3> {};
108  class ResultBits: public BitField<int, 3, 3> {};
109  class IndexBits: public BitField<int, 6, 3> {};
110  class LookupModeBits: public BitField<LookupMode, 9, 1> {};
111
112  DEFINE_NULL_CALL_INTERFACE_DESCRIPTOR();
113  DEFINE_PLATFORM_CODE_STUB(NameDictionaryLookup, PlatformCodeStub);
114};
115
116
117class RecordWriteStub: public PlatformCodeStub {
118 public:
119  RecordWriteStub(Isolate* isolate,
120                  Register object,
121                  Register value,
122                  Register address,
123                  RememberedSetAction remembered_set_action,
124                  SaveFPRegsMode fp_mode)
125      : PlatformCodeStub(isolate),
126        regs_(object,   // An input reg.
127              address,  // An input reg.
128              value) {  // One scratch reg.
129    minor_key_ = ObjectBits::encode(object.code()) |
130                 ValueBits::encode(value.code()) |
131                 AddressBits::encode(address.code()) |
132                 RememberedSetActionBits::encode(remembered_set_action) |
133                 SaveFPRegsModeBits::encode(fp_mode);
134  }
135
136  RecordWriteStub(uint32_t key, Isolate* isolate)
137      : PlatformCodeStub(key, isolate), regs_(object(), address(), value()) {}
138
139  enum Mode {
140    STORE_BUFFER_ONLY,
141    INCREMENTAL,
142    INCREMENTAL_COMPACTION
143  };
144
145  virtual bool SometimesSetsUpAFrame() { return false; }
146
147  static const byte kTwoByteNopInstruction = 0x3c;  // Cmpb al, #imm8.
148  static const byte kTwoByteJumpInstruction = 0xeb;  // Jmp #imm8.
149
150  static const byte kFiveByteNopInstruction = 0x3d;  // Cmpl eax, #imm32.
151  static const byte kFiveByteJumpInstruction = 0xe9;  // Jmp #imm32.
152
153  static Mode GetMode(Code* stub) {
154    byte first_instruction = stub->instruction_start()[0];
155    byte second_instruction = stub->instruction_start()[2];
156
157    if (first_instruction == kTwoByteJumpInstruction) {
158      return INCREMENTAL;
159    }
160
161    DCHECK(first_instruction == kTwoByteNopInstruction);
162
163    if (second_instruction == kFiveByteJumpInstruction) {
164      return INCREMENTAL_COMPACTION;
165    }
166
167    DCHECK(second_instruction == kFiveByteNopInstruction);
168
169    return STORE_BUFFER_ONLY;
170  }
171
172  static void Patch(Code* stub, Mode mode) {
173    switch (mode) {
174      case STORE_BUFFER_ONLY:
175        DCHECK(GetMode(stub) == INCREMENTAL ||
176               GetMode(stub) == INCREMENTAL_COMPACTION);
177        stub->instruction_start()[0] = kTwoByteNopInstruction;
178        stub->instruction_start()[2] = kFiveByteNopInstruction;
179        break;
180      case INCREMENTAL:
181        DCHECK(GetMode(stub) == STORE_BUFFER_ONLY);
182        stub->instruction_start()[0] = kTwoByteJumpInstruction;
183        break;
184      case INCREMENTAL_COMPACTION:
185        DCHECK(GetMode(stub) == STORE_BUFFER_ONLY);
186        stub->instruction_start()[0] = kTwoByteNopInstruction;
187        stub->instruction_start()[2] = kFiveByteJumpInstruction;
188        break;
189    }
190    DCHECK(GetMode(stub) == mode);
191    CpuFeatures::FlushICache(stub->instruction_start(), 7);
192  }
193
194  DEFINE_NULL_CALL_INTERFACE_DESCRIPTOR();
195
196 private:
197  // This is a helper class for freeing up 3 scratch registers, where the third
198  // is always ecx (needed for shift operations).  The input is two registers
199  // that must be preserved and one scratch register provided by the caller.
200  class RegisterAllocation {
201   public:
202    RegisterAllocation(Register object,
203                       Register address,
204                       Register scratch0)
205        : object_orig_(object),
206          address_orig_(address),
207          scratch0_orig_(scratch0),
208          object_(object),
209          address_(address),
210          scratch0_(scratch0) {
211      DCHECK(!AreAliased(scratch0, object, address, no_reg));
212      scratch1_ = GetRegThatIsNotEcxOr(object_, address_, scratch0_);
213      if (scratch0.is(ecx)) {
214        scratch0_ = GetRegThatIsNotEcxOr(object_, address_, scratch1_);
215      }
216      if (object.is(ecx)) {
217        object_ = GetRegThatIsNotEcxOr(address_, scratch0_, scratch1_);
218      }
219      if (address.is(ecx)) {
220        address_ = GetRegThatIsNotEcxOr(object_, scratch0_, scratch1_);
221      }
222      DCHECK(!AreAliased(scratch0_, object_, address_, ecx));
223    }
224
225    void Save(MacroAssembler* masm) {
226      DCHECK(!address_orig_.is(object_));
227      DCHECK(object_.is(object_orig_) || address_.is(address_orig_));
228      DCHECK(!AreAliased(object_, address_, scratch1_, scratch0_));
229      DCHECK(!AreAliased(object_orig_, address_, scratch1_, scratch0_));
230      DCHECK(!AreAliased(object_, address_orig_, scratch1_, scratch0_));
231      // We don't have to save scratch0_orig_ because it was given to us as
232      // a scratch register.  But if we had to switch to a different reg then
233      // we should save the new scratch0_.
234      if (!scratch0_.is(scratch0_orig_)) masm->push(scratch0_);
235      if (!ecx.is(scratch0_orig_) &&
236          !ecx.is(object_orig_) &&
237          !ecx.is(address_orig_)) {
238        masm->push(ecx);
239      }
240      masm->push(scratch1_);
241      if (!address_.is(address_orig_)) {
242        masm->push(address_);
243        masm->mov(address_, address_orig_);
244      }
245      if (!object_.is(object_orig_)) {
246        masm->push(object_);
247        masm->mov(object_, object_orig_);
248      }
249    }
250
251    void Restore(MacroAssembler* masm) {
252      // These will have been preserved the entire time, so we just need to move
253      // them back.  Only in one case is the orig_ reg different from the plain
254      // one, since only one of them can alias with ecx.
255      if (!object_.is(object_orig_)) {
256        masm->mov(object_orig_, object_);
257        masm->pop(object_);
258      }
259      if (!address_.is(address_orig_)) {
260        masm->mov(address_orig_, address_);
261        masm->pop(address_);
262      }
263      masm->pop(scratch1_);
264      if (!ecx.is(scratch0_orig_) &&
265          !ecx.is(object_orig_) &&
266          !ecx.is(address_orig_)) {
267        masm->pop(ecx);
268      }
269      if (!scratch0_.is(scratch0_orig_)) masm->pop(scratch0_);
270    }
271
272    // If we have to call into C then we need to save and restore all caller-
273    // saved registers that were not already preserved.  The caller saved
274    // registers are eax, ecx and edx.  The three scratch registers (incl. ecx)
275    // will be restored by other means so we don't bother pushing them here.
276    void SaveCallerSaveRegisters(MacroAssembler* masm, SaveFPRegsMode mode) {
277      if (!scratch0_.is(eax) && !scratch1_.is(eax)) masm->push(eax);
278      if (!scratch0_.is(edx) && !scratch1_.is(edx)) masm->push(edx);
279      if (mode == kSaveFPRegs) {
280        masm->sub(esp,
281                  Immediate(kDoubleSize * (XMMRegister::kMaxNumRegisters - 1)));
282        // Save all XMM registers except XMM0.
283        for (int i = XMMRegister::kMaxNumRegisters - 1; i > 0; i--) {
284          XMMRegister reg = XMMRegister::from_code(i);
285          masm->movsd(Operand(esp, (i - 1) * kDoubleSize), reg);
286        }
287      }
288    }
289
290    inline void RestoreCallerSaveRegisters(MacroAssembler*masm,
291                                           SaveFPRegsMode mode) {
292      if (mode == kSaveFPRegs) {
293        // Restore all XMM registers except XMM0.
294        for (int i = XMMRegister::kMaxNumRegisters - 1; i > 0; i--) {
295          XMMRegister reg = XMMRegister::from_code(i);
296          masm->movsd(reg, Operand(esp, (i - 1) * kDoubleSize));
297        }
298        masm->add(esp,
299                  Immediate(kDoubleSize * (XMMRegister::kMaxNumRegisters - 1)));
300      }
301      if (!scratch0_.is(edx) && !scratch1_.is(edx)) masm->pop(edx);
302      if (!scratch0_.is(eax) && !scratch1_.is(eax)) masm->pop(eax);
303    }
304
305    inline Register object() { return object_; }
306    inline Register address() { return address_; }
307    inline Register scratch0() { return scratch0_; }
308    inline Register scratch1() { return scratch1_; }
309
310   private:
311    Register object_orig_;
312    Register address_orig_;
313    Register scratch0_orig_;
314    Register object_;
315    Register address_;
316    Register scratch0_;
317    Register scratch1_;
318    // Third scratch register is always ecx.
319
320    Register GetRegThatIsNotEcxOr(Register r1,
321                                  Register r2,
322                                  Register r3) {
323      for (int i = 0; i < Register::NumAllocatableRegisters(); i++) {
324        Register candidate = Register::FromAllocationIndex(i);
325        if (candidate.is(ecx)) continue;
326        if (candidate.is(r1)) continue;
327        if (candidate.is(r2)) continue;
328        if (candidate.is(r3)) continue;
329        return candidate;
330      }
331      UNREACHABLE();
332      return no_reg;
333    }
334    friend class RecordWriteStub;
335  };
336
337  enum OnNoNeedToInformIncrementalMarker {
338    kReturnOnNoNeedToInformIncrementalMarker,
339    kUpdateRememberedSetOnNoNeedToInformIncrementalMarker
340  };
341
342  virtual inline Major MajorKey() const FINAL OVERRIDE { return RecordWrite; }
343
344  virtual void Generate(MacroAssembler* masm) OVERRIDE;
345  void GenerateIncremental(MacroAssembler* masm, Mode mode);
346  void CheckNeedsToInformIncrementalMarker(
347      MacroAssembler* masm,
348      OnNoNeedToInformIncrementalMarker on_no_need,
349      Mode mode);
350  void InformIncrementalMarker(MacroAssembler* masm);
351
352  void Activate(Code* code) {
353    code->GetHeap()->incremental_marking()->ActivateGeneratedStub(code);
354  }
355
356  Register object() const {
357    return Register::from_code(ObjectBits::decode(minor_key_));
358  }
359
360  Register value() const {
361    return Register::from_code(ValueBits::decode(minor_key_));
362  }
363
364  Register address() const {
365    return Register::from_code(AddressBits::decode(minor_key_));
366  }
367
368  RememberedSetAction remembered_set_action() const {
369    return RememberedSetActionBits::decode(minor_key_);
370  }
371
372  SaveFPRegsMode save_fp_regs_mode() const {
373    return SaveFPRegsModeBits::decode(minor_key_);
374  }
375
376  class ObjectBits: public BitField<int, 0, 3> {};
377  class ValueBits: public BitField<int, 3, 3> {};
378  class AddressBits: public BitField<int, 6, 3> {};
379  class RememberedSetActionBits: public BitField<RememberedSetAction, 9, 1> {};
380  class SaveFPRegsModeBits: public BitField<SaveFPRegsMode, 10, 1> {};
381
382  RegisterAllocation regs_;
383
384  DISALLOW_COPY_AND_ASSIGN(RecordWriteStub);
385};
386
387
388} }  // namespace v8::internal
389
390#endif  // V8_IA32_CODE_STUBS_IA32_H_
391