code-stubs-ia32.h 10.6 KB
Newer Older
1
// Copyright 2011 the V8 project authors. All rights reserved.
2 3
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
4 5 6 7 8 9 10 11 12 13

#ifndef V8_IA32_CODE_STUBS_IA32_H_
#define V8_IA32_CODE_STUBS_IA32_H_

namespace v8 {
namespace internal {


class StringHelper : public AllStatic {
 public:
14 15 16 17 18 19 20 21 22
  // Compares two flat one byte strings and returns result in eax.
  static void GenerateCompareFlatOneByteStrings(MacroAssembler* masm,
                                                Register left, Register right,
                                                Register scratch1,
                                                Register scratch2,
                                                Register scratch3);

  // Compares two flat one byte strings for equality and returns result in eax.
  static void GenerateFlatOneByteStringEquals(MacroAssembler* masm,
23
                                              Register left, Register right,
24
                                              Register scratch1,
25
                                              Register scratch2);
26

27
 private:
28 29 30
  static void GenerateOneByteCharsCompareLoop(
      MacroAssembler* masm, Register left, Register right, Register length,
      Register scratch, Label* chars_not_equal,
31
      Label::Distance chars_not_equal_near = Label::kFar);
32 33

  DISALLOW_IMPLICIT_CONSTRUCTORS(StringHelper);
34 35 36
};


37
class NameDictionaryLookupStub: public PlatformCodeStub {
38 39 40
 public:
  enum LookupMode { POSITIVE_LOOKUP, NEGATIVE_LOOKUP };

41 42 43 44 45 46 47
  NameDictionaryLookupStub(Isolate* isolate, Register dictionary,
                           Register result, Register index, LookupMode mode)
      : PlatformCodeStub(isolate) {
    minor_key_ = DictionaryBits::encode(dictionary.code()) |
                 ResultBits::encode(result.code()) |
                 IndexBits::encode(index.code()) | LookupModeBits::encode(mode);
  }
48

49 50 51 52
  static void GenerateNegativeLookup(MacroAssembler* masm,
                                     Label* miss,
                                     Label* done,
                                     Register properties,
53
                                     Handle<Name> name,
54 55
                                     Register r0);

56
  bool SometimesSetsUpAFrame() override { return false; }
57

58 59 60 61 62
 private:
  static const int kInlinedProbes = 4;
  static const int kTotalProbes = 20;

  static const int kCapacityOffset =
63 64
      NameDictionary::kHeaderSize +
      NameDictionary::kCapacityIndex * kPointerSize;
65 66

  static const int kElementsStartOffset =
67 68
      NameDictionary::kHeaderSize +
      NameDictionary::kElementsStartIndex * kPointerSize;
69

70 71 72 73 74 75
  Register dictionary() const {
    return Register::from_code(DictionaryBits::decode(minor_key_));
  }

  Register result() const {
    return Register::from_code(ResultBits::decode(minor_key_));
76 77
  }

78 79 80 81 82 83
  Register index() const {
    return Register::from_code(IndexBits::decode(minor_key_));
  }

  LookupMode mode() const { return LookupModeBits::decode(minor_key_); }

84 85 86 87 88
  class DictionaryBits: public BitField<int, 0, 3> {};
  class ResultBits: public BitField<int, 3, 3> {};
  class IndexBits: public BitField<int, 6, 3> {};
  class LookupModeBits: public BitField<LookupMode, 9, 1> {};

89
  DEFINE_NULL_CALL_INTERFACE_DESCRIPTOR();
90
  DEFINE_PLATFORM_CODE_STUB(NameDictionaryLookup, PlatformCodeStub);
91 92 93
};


94
class RecordWriteStub: public PlatformCodeStub {
95
 public:
96 97
  RecordWriteStub(Isolate* isolate,
                  Register object,
98 99 100 101
                  Register value,
                  Register address,
                  RememberedSetAction remembered_set_action,
                  SaveFPRegsMode fp_mode)
102
      : PlatformCodeStub(isolate),
103 104 105
        regs_(object,   // An input reg.
              address,  // An input reg.
              value) {  // One scratch reg.
106 107 108 109 110
    minor_key_ = ObjectBits::encode(object.code()) |
                 ValueBits::encode(value.code()) |
                 AddressBits::encode(address.code()) |
                 RememberedSetActionBits::encode(remembered_set_action) |
                 SaveFPRegsModeBits::encode(fp_mode);
111 112
  }

113 114 115
  RecordWriteStub(uint32_t key, Isolate* isolate)
      : PlatformCodeStub(key, isolate), regs_(object(), address(), value()) {}

116 117 118 119 120 121
  enum Mode {
    STORE_BUFFER_ONLY,
    INCREMENTAL,
    INCREMENTAL_COMPACTION
  };

122
  bool SometimesSetsUpAFrame() override { return false; }
123 124 125 126 127 128 129

  static const byte kTwoByteNopInstruction = 0x3c;  // Cmpb al, #imm8.
  static const byte kTwoByteJumpInstruction = 0xeb;  // Jmp #imm8.

  static const byte kFiveByteNopInstruction = 0x3d;  // Cmpl eax, #imm32.
  static const byte kFiveByteJumpInstruction = 0xe9;  // Jmp #imm32.

130
  static Mode GetMode(Code* stub);
131

132
  static void Patch(Code* stub, Mode mode);
133

134 135
  DEFINE_NULL_CALL_INTERFACE_DESCRIPTOR();

136 137 138 139 140 141
 private:
  // This is a helper class for freeing up 3 scratch registers, where the third
  // is always ecx (needed for shift operations).  The input is two registers
  // that must be preserved and one scratch register provided by the caller.
  class RegisterAllocation {
   public:
142
    RegisterAllocation(Register object, Register address, Register scratch0)
143 144 145 146 147
        : object_orig_(object),
          address_orig_(address),
          scratch0_orig_(scratch0),
          object_(object),
          address_(address),
148 149
          scratch0_(scratch0),
          scratch1_(no_reg) {
150
      DCHECK(!AreAliased(scratch0, object, address, no_reg));
151
      scratch1_ = GetRegThatIsNotEcxOr(object_, address_, scratch0_);
152
      if (scratch0 == ecx) {
153 154
        scratch0_ = GetRegThatIsNotEcxOr(object_, address_, scratch1_);
      }
155
      if (object == ecx) {
156 157
        object_ = GetRegThatIsNotEcxOr(address_, scratch0_, scratch1_);
      }
158
      if (address == ecx) {
159 160
        address_ = GetRegThatIsNotEcxOr(object_, scratch0_, scratch1_);
      }
161
      DCHECK(!AreAliased(scratch0_, object_, address_, ecx));
162 163 164
    }

    void Save(MacroAssembler* masm) {
165 166
      DCHECK(address_orig_ != object_);
      DCHECK(object_ == object_orig_ || address_ == address_orig_);
167 168 169
      DCHECK(!AreAliased(object_, address_, scratch1_, scratch0_));
      DCHECK(!AreAliased(object_orig_, address_, scratch1_, scratch0_));
      DCHECK(!AreAliased(object_, address_orig_, scratch1_, scratch0_));
170 171 172
      // We don't have to save scratch0_orig_ because it was given to us as
      // a scratch register.  But if we had to switch to a different reg then
      // we should save the new scratch0_.
173 174 175
      if (scratch0_ != scratch0_orig_) masm->push(scratch0_);
      if (ecx != scratch0_orig_ && ecx != object_orig_ &&
          ecx != address_orig_) {
176 177 178
        masm->push(ecx);
      }
      masm->push(scratch1_);
179
      if (address_ != address_orig_) {
180 181 182
        masm->push(address_);
        masm->mov(address_, address_orig_);
      }
183
      if (object_ != object_orig_) {
184 185 186 187 188 189 190 191 192
        masm->push(object_);
        masm->mov(object_, object_orig_);
      }
    }

    void Restore(MacroAssembler* masm) {
      // These will have been preserved the entire time, so we just need to move
      // them back.  Only in one case is the orig_ reg different from the plain
      // one, since only one of them can alias with ecx.
193
      if (object_ != object_orig_) {
194 195 196
        masm->mov(object_orig_, object_);
        masm->pop(object_);
      }
197
      if (address_ != address_orig_) {
198 199 200 201
        masm->mov(address_orig_, address_);
        masm->pop(address_);
      }
      masm->pop(scratch1_);
202 203
      if (ecx != scratch0_orig_ && ecx != object_orig_ &&
          ecx != address_orig_) {
204 205
        masm->pop(ecx);
      }
206
      if (scratch0_ != scratch0_orig_) masm->pop(scratch0_);
207 208 209 210 211 212 213
    }

    // If we have to call into C then we need to save and restore all caller-
    // saved registers that were not already preserved.  The caller saved
    // registers are eax, ecx and edx.  The three scratch registers (incl. ecx)
    // will be restored by other means so we don't bother pushing them here.
    void SaveCallerSaveRegisters(MacroAssembler* masm, SaveFPRegsMode mode) {
214
      masm->PushCallerSaved(mode, ecx, scratch0_, scratch1_);
215 216
    }

217
    inline void RestoreCallerSaveRegisters(MacroAssembler* masm,
218
                                           SaveFPRegsMode mode) {
219
      masm->PopCallerSaved(mode, ecx, scratch0_, scratch1_);
220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239
    }

    inline Register object() { return object_; }
    inline Register address() { return address_; }
    inline Register scratch0() { return scratch0_; }
    inline Register scratch1() { return scratch1_; }

   private:
    Register object_orig_;
    Register address_orig_;
    Register scratch0_orig_;
    Register object_;
    Register address_;
    Register scratch0_;
    Register scratch1_;
    // Third scratch register is always ecx.

    Register GetRegThatIsNotEcxOr(Register r1,
                                  Register r2,
                                  Register r3) {
240
      for (int i = 0; i < Register::kNumRegisters; i++) {
241
        if (RegisterConfiguration::Default()->IsAllocatableGeneralCode(i)) {
242
          Register candidate = Register::from_code(i);
243 244 245 246
          if (candidate != ecx && candidate != r1 && candidate != r2 &&
              candidate != r3) {
            return candidate;
          }
247
        }
248 249 250 251 252 253 254 255 256
      }
      UNREACHABLE();
    }
    friend class RecordWriteStub;
  };

  enum OnNoNeedToInformIncrementalMarker {
    kReturnOnNoNeedToInformIncrementalMarker,
    kUpdateRememberedSetOnNoNeedToInformIncrementalMarker
257 258
  };

259
  inline Major MajorKey() const final { return RecordWrite; }
260

261
  void Generate(MacroAssembler* masm) override;
262 263 264 265 266
  void GenerateIncremental(MacroAssembler* masm, Mode mode);
  void CheckNeedsToInformIncrementalMarker(
      MacroAssembler* masm,
      OnNoNeedToInformIncrementalMarker on_no_need,
      Mode mode);
267
  void InformIncrementalMarker(MacroAssembler* masm);
268

269
  void Activate(Code* code) override;
270

271 272
  Register object() const {
    return Register::from_code(ObjectBits::decode(minor_key_));
273 274
  }

275 276 277 278 279 280 281 282 283 284 285 286 287 288
  Register value() const {
    return Register::from_code(ValueBits::decode(minor_key_));
  }

  Register address() const {
    return Register::from_code(AddressBits::decode(minor_key_));
  }

  RememberedSetAction remembered_set_action() const {
    return RememberedSetActionBits::decode(minor_key_);
  }

  SaveFPRegsMode save_fp_regs_mode() const {
    return SaveFPRegsModeBits::decode(minor_key_);
289 290 291 292 293 294 295 296 297
  }

  class ObjectBits: public BitField<int, 0, 3> {};
  class ValueBits: public BitField<int, 3, 3> {};
  class AddressBits: public BitField<int, 6, 3> {};
  class RememberedSetActionBits: public BitField<RememberedSetAction, 9, 1> {};
  class SaveFPRegsModeBits: public BitField<SaveFPRegsMode, 10, 1> {};

  RegisterAllocation regs_;
298 299

  DISALLOW_COPY_AND_ASSIGN(RecordWriteStub);
300 301 302
};


303 304
}  // namespace internal
}  // namespace v8
305 306

#endif  // V8_IA32_CODE_STUBS_IA32_H_