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_X87_CODE_STUBS_X87_H_
6#define V8_X87_CODE_STUBS_X87_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, Register object, Register value,
120                  Register address, RememberedSetAction remembered_set_action,
121                  SaveFPRegsMode fp_mode)
122      : PlatformCodeStub(isolate),
123        regs_(object,   // An input reg.
124              address,  // An input reg.
125              value) {  // One scratch reg.
126    minor_key_ = ObjectBits::encode(object.code()) |
127                 ValueBits::encode(value.code()) |
128                 AddressBits::encode(address.code()) |
129                 RememberedSetActionBits::encode(remembered_set_action) |
130                 SaveFPRegsModeBits::encode(fp_mode);
131  }
132
133  RecordWriteStub(uint32_t key, Isolate* isolate)
134      : PlatformCodeStub(key, isolate), regs_(object(), address(), value()) {}
135
136  enum Mode {
137    STORE_BUFFER_ONLY,
138    INCREMENTAL,
139    INCREMENTAL_COMPACTION
140  };
141
142  virtual bool SometimesSetsUpAFrame() { return false; }
143
144  static const byte kTwoByteNopInstruction = 0x3c;  // Cmpb al, #imm8.
145  static const byte kTwoByteJumpInstruction = 0xeb;  // Jmp #imm8.
146
147  static const byte kFiveByteNopInstruction = 0x3d;  // Cmpl eax, #imm32.
148  static const byte kFiveByteJumpInstruction = 0xe9;  // Jmp #imm32.
149
150  static Mode GetMode(Code* stub) {
151    byte first_instruction = stub->instruction_start()[0];
152    byte second_instruction = stub->instruction_start()[2];
153
154    if (first_instruction == kTwoByteJumpInstruction) {
155      return INCREMENTAL;
156    }
157
158    DCHECK(first_instruction == kTwoByteNopInstruction);
159
160    if (second_instruction == kFiveByteJumpInstruction) {
161      return INCREMENTAL_COMPACTION;
162    }
163
164    DCHECK(second_instruction == kFiveByteNopInstruction);
165
166    return STORE_BUFFER_ONLY;
167  }
168
169  static void Patch(Code* stub, Mode mode) {
170    switch (mode) {
171      case STORE_BUFFER_ONLY:
172        DCHECK(GetMode(stub) == INCREMENTAL ||
173               GetMode(stub) == INCREMENTAL_COMPACTION);
174        stub->instruction_start()[0] = kTwoByteNopInstruction;
175        stub->instruction_start()[2] = kFiveByteNopInstruction;
176        break;
177      case INCREMENTAL:
178        DCHECK(GetMode(stub) == STORE_BUFFER_ONLY);
179        stub->instruction_start()[0] = kTwoByteJumpInstruction;
180        break;
181      case INCREMENTAL_COMPACTION:
182        DCHECK(GetMode(stub) == STORE_BUFFER_ONLY);
183        stub->instruction_start()[0] = kTwoByteNopInstruction;
184        stub->instruction_start()[2] = kFiveByteJumpInstruction;
185        break;
186    }
187    DCHECK(GetMode(stub) == mode);
188    CpuFeatures::FlushICache(stub->instruction_start(), 7);
189  }
190
191  DEFINE_NULL_CALL_INTERFACE_DESCRIPTOR();
192
193 private:
194  // This is a helper class for freeing up 3 scratch registers, where the third
195  // is always ecx (needed for shift operations).  The input is two registers
196  // that must be preserved and one scratch register provided by the caller.
197  class RegisterAllocation {
198   public:
199    RegisterAllocation(Register object,
200                       Register address,
201                       Register scratch0)
202        : object_orig_(object),
203          address_orig_(address),
204          scratch0_orig_(scratch0),
205          object_(object),
206          address_(address),
207          scratch0_(scratch0) {
208      DCHECK(!AreAliased(scratch0, object, address, no_reg));
209      scratch1_ = GetRegThatIsNotEcxOr(object_, address_, scratch0_);
210      if (scratch0.is(ecx)) {
211        scratch0_ = GetRegThatIsNotEcxOr(object_, address_, scratch1_);
212      }
213      if (object.is(ecx)) {
214        object_ = GetRegThatIsNotEcxOr(address_, scratch0_, scratch1_);
215      }
216      if (address.is(ecx)) {
217        address_ = GetRegThatIsNotEcxOr(object_, scratch0_, scratch1_);
218      }
219      DCHECK(!AreAliased(scratch0_, object_, address_, ecx));
220    }
221
222    void Save(MacroAssembler* masm) {
223      DCHECK(!address_orig_.is(object_));
224      DCHECK(object_.is(object_orig_) || address_.is(address_orig_));
225      DCHECK(!AreAliased(object_, address_, scratch1_, scratch0_));
226      DCHECK(!AreAliased(object_orig_, address_, scratch1_, scratch0_));
227      DCHECK(!AreAliased(object_, address_orig_, scratch1_, scratch0_));
228      // We don't have to save scratch0_orig_ because it was given to us as
229      // a scratch register.  But if we had to switch to a different reg then
230      // we should save the new scratch0_.
231      if (!scratch0_.is(scratch0_orig_)) masm->push(scratch0_);
232      if (!ecx.is(scratch0_orig_) &&
233          !ecx.is(object_orig_) &&
234          !ecx.is(address_orig_)) {
235        masm->push(ecx);
236      }
237      masm->push(scratch1_);
238      if (!address_.is(address_orig_)) {
239        masm->push(address_);
240        masm->mov(address_, address_orig_);
241      }
242      if (!object_.is(object_orig_)) {
243        masm->push(object_);
244        masm->mov(object_, object_orig_);
245      }
246    }
247
248    void Restore(MacroAssembler* masm) {
249      // These will have been preserved the entire time, so we just need to move
250      // them back.  Only in one case is the orig_ reg different from the plain
251      // one, since only one of them can alias with ecx.
252      if (!object_.is(object_orig_)) {
253        masm->mov(object_orig_, object_);
254        masm->pop(object_);
255      }
256      if (!address_.is(address_orig_)) {
257        masm->mov(address_orig_, address_);
258        masm->pop(address_);
259      }
260      masm->pop(scratch1_);
261      if (!ecx.is(scratch0_orig_) &&
262          !ecx.is(object_orig_) &&
263          !ecx.is(address_orig_)) {
264        masm->pop(ecx);
265      }
266      if (!scratch0_.is(scratch0_orig_)) masm->pop(scratch0_);
267    }
268
269    // If we have to call into C then we need to save and restore all caller-
270    // saved registers that were not already preserved.  The caller saved
271    // registers are eax, ecx and edx.  The three scratch registers (incl. ecx)
272    // will be restored by other means so we don't bother pushing them here.
273    void SaveCallerSaveRegisters(MacroAssembler* masm, SaveFPRegsMode mode) {
274      if (!scratch0_.is(eax) && !scratch1_.is(eax)) masm->push(eax);
275      if (!scratch0_.is(edx) && !scratch1_.is(edx)) masm->push(edx);
276      if (mode == kSaveFPRegs) {
277        // Save FPU state in m108byte.
278        masm->sub(esp, Immediate(108));
279        masm->fnsave(Operand(esp, 0));
280      }
281    }
282
283    inline void RestoreCallerSaveRegisters(MacroAssembler* masm,
284                                           SaveFPRegsMode mode) {
285      if (mode == kSaveFPRegs) {
286        // Restore FPU state in m108byte.
287        masm->frstor(Operand(esp, 0));
288        masm->add(esp, Immediate(108));
289      }
290      if (!scratch0_.is(edx) && !scratch1_.is(edx)) masm->pop(edx);
291      if (!scratch0_.is(eax) && !scratch1_.is(eax)) masm->pop(eax);
292    }
293
294    inline Register object() { return object_; }
295    inline Register address() { return address_; }
296    inline Register scratch0() { return scratch0_; }
297    inline Register scratch1() { return scratch1_; }
298
299   private:
300    Register object_orig_;
301    Register address_orig_;
302    Register scratch0_orig_;
303    Register object_;
304    Register address_;
305    Register scratch0_;
306    Register scratch1_;
307    // Third scratch register is always ecx.
308
309    Register GetRegThatIsNotEcxOr(Register r1,
310                                  Register r2,
311                                  Register r3) {
312      for (int i = 0; i < Register::NumAllocatableRegisters(); i++) {
313        Register candidate = Register::FromAllocationIndex(i);
314        if (candidate.is(ecx)) continue;
315        if (candidate.is(r1)) continue;
316        if (candidate.is(r2)) continue;
317        if (candidate.is(r3)) continue;
318        return candidate;
319      }
320      UNREACHABLE();
321      return no_reg;
322    }
323    friend class RecordWriteStub;
324  };
325
326  enum OnNoNeedToInformIncrementalMarker {
327    kReturnOnNoNeedToInformIncrementalMarker,
328    kUpdateRememberedSetOnNoNeedToInformIncrementalMarker
329  };
330
331  virtual inline Major MajorKey() const FINAL OVERRIDE { return RecordWrite; }
332
333  virtual void Generate(MacroAssembler* masm) OVERRIDE;
334  void GenerateIncremental(MacroAssembler* masm, Mode mode);
335  void CheckNeedsToInformIncrementalMarker(
336      MacroAssembler* masm,
337      OnNoNeedToInformIncrementalMarker on_no_need,
338      Mode mode);
339  void InformIncrementalMarker(MacroAssembler* masm);
340
341  void Activate(Code* code) {
342    code->GetHeap()->incremental_marking()->ActivateGeneratedStub(code);
343  }
344
345  Register object() const {
346    return Register::from_code(ObjectBits::decode(minor_key_));
347  }
348
349  Register value() const {
350    return Register::from_code(ValueBits::decode(minor_key_));
351  }
352
353  Register address() const {
354    return Register::from_code(AddressBits::decode(minor_key_));
355  }
356
357  RememberedSetAction remembered_set_action() const {
358    return RememberedSetActionBits::decode(minor_key_);
359  }
360
361  SaveFPRegsMode save_fp_regs_mode() const {
362    return SaveFPRegsModeBits::decode(minor_key_);
363  }
364
365  class ObjectBits: public BitField<int, 0, 3> {};
366  class ValueBits: public BitField<int, 3, 3> {};
367  class AddressBits: public BitField<int, 6, 3> {};
368  class RememberedSetActionBits: public BitField<RememberedSetAction, 9, 1> {};
369  class SaveFPRegsModeBits : public BitField<SaveFPRegsMode, 10, 1> {};
370
371  RegisterAllocation regs_;
372
373  DISALLOW_COPY_AND_ASSIGN(RecordWriteStub);
374};
375
376
377} }  // namespace v8::internal
378
379#endif  // V8_X87_CODE_STUBS_X87_H_
380