src/v8/src/ia32/code-stubs-ia32.h

   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
   8 #include "src/ic-inl.h"
   9 #include "src/macro-assembler.h"
  10
  11 namespace v8 {
  12 namespace internal {
  13
  14
  15 void ArrayNativeCode(MacroAssembler* masm,
  16                      bool construct_call,
  17                      Label* call_generic_code);
  18
  19
  20 class StoreBufferOverflowStub: public PlatformCodeStub {
  21  public:
  22   StoreBufferOverflowStub(Isolate* isolate, SaveFPRegsMode save_fp)
  23       : PlatformCodeStub(isolate), save_doubles_(save_fp) { }
  24
  25   void Generate(MacroAssembler* masm);
  26
  27   static void GenerateFixedRegStubsAheadOfTime(Isolate* isolate);
  28   virtual bool SometimesSetsUpAFrame() { return false; }
  29
  30  private:
  31   SaveFPRegsMode save_doubles_;
  32
  33   Major MajorKey() const { return StoreBufferOverflow; }
  34   int MinorKey() const { return (save_doubles_ == kSaveFPRegs) ? 1 : 0; }
  35 };
  36
  37
  38 class StringHelper : public AllStatic {
  39  public:
  40   // Generate code for copying characters using the rep movs instruction.
  41   // Copies ecx characters from esi to edi. Copying of overlapping regions is
  42   // not supported.
  43   static void GenerateCopyCharacters(MacroAssembler* masm,
  44                                      Register dest,
  45                                      Register src,
  46                                      Register count,
  47                                      Register scratch,
  48                                      String::Encoding encoding);
  49
  50   // Generate string hash.
  51   static void GenerateHashInit(MacroAssembler* masm,
  52                                Register hash,
  53                                Register character,
  54                                Register scratch);
  55   static void GenerateHashAddCharacter(MacroAssembler* masm,
  56                                        Register hash,
  57                                        Register character,
  58                                        Register scratch);
  59   static void GenerateHashGetHash(MacroAssembler* masm,
  60                                   Register hash,
  61                                   Register scratch);
  62
  63  private:
  64   DISALLOW_IMPLICIT_CONSTRUCTORS(StringHelper);
  65 };
  66
  67
  68 class SubStringStub: public PlatformCodeStub {
  69  public:
  70   explicit SubStringStub(Isolate* isolate) : PlatformCodeStub(isolate) {}
  71
  72  private:
  73   Major MajorKey() const { return SubString; }
  74   int MinorKey() const { return 0; }
  75
  76   void Generate(MacroAssembler* masm);
  77 };
  78
  79
  80 class StringCompareStub: public PlatformCodeStub {
  81  public:
  82   explicit StringCompareStub(Isolate* isolate) : PlatformCodeStub(isolate) { }
  83
  84   // Compares two flat ASCII strings and returns result in eax.
  85   static void GenerateCompareFlatAsciiStrings(MacroAssembler* masm,
  86                                               Register left,
  87                                               Register right,
  88                                               Register scratch1,
  89                                               Register scratch2,
  90                                               Register scratch3);
  91
  92   // Compares two flat ASCII strings for equality and returns result
  93   // in eax.
  94   static void GenerateFlatAsciiStringEquals(MacroAssembler* masm,
  95                                             Register left,
  96                                             Register right,
  97                                             Register scratch1,
  98                                             Register scratch2);
  99
 100  private:
 101   virtual Major MajorKey() const { return StringCompare; }
 102   virtual int MinorKey() const { return 0; }
 103   virtual void Generate(MacroAssembler* masm);
 104
 105   static void GenerateAsciiCharsCompareLoop(
 106       MacroAssembler* masm,
 107       Register left,
 108       Register right,
 109       Register length,
 110       Register scratch,
 111       Label* chars_not_equal,
 112       Label::Distance chars_not_equal_near = Label::kFar);
 113 };
 114
 115
 116 class NameDictionaryLookupStub: public PlatformCodeStub {
 117  public:
 118   enum LookupMode { POSITIVE_LOOKUP, NEGATIVE_LOOKUP };
 119
 120   NameDictionaryLookupStub(Isolate* isolate,
 121                            Register dictionary,
 122                            Register result,
 123                            Register index,
 124                            LookupMode mode)
 125       : PlatformCodeStub(isolate),
 126         dictionary_(dictionary), result_(result), index_(index), mode_(mode) { }
 127
 128   void Generate(MacroAssembler* masm);
 129
 130   static void GenerateNegativeLookup(MacroAssembler* masm,
 131                                      Label* miss,
 132                                      Label* done,
 133                                      Register properties,
 134                                      Handle<Name> name,
 135                                      Register r0);
 136
 137   static void GeneratePositiveLookup(MacroAssembler* masm,
 138                                      Label* miss,
 139                                      Label* done,
 140                                      Register elements,
 141                                      Register name,
 142                                      Register r0,
 143                                      Register r1);
 144
 145   virtual bool SometimesSetsUpAFrame() { return false; }
 146
 147  private:
 148   static const int kInlinedProbes = 4;
 149   static const int kTotalProbes = 20;
 150
 151   static const int kCapacityOffset =
 152       NameDictionary::kHeaderSize +
 153       NameDictionary::kCapacityIndex * kPointerSize;
 154
 155   static const int kElementsStartOffset =
 156       NameDictionary::kHeaderSize +
 157       NameDictionary::kElementsStartIndex * kPointerSize;
 158
 159   Major MajorKey() const { return NameDictionaryLookup; }
 160
 161   int MinorKey() const {
 162     return DictionaryBits::encode(dictionary_.code()) |
 163         ResultBits::encode(result_.code()) |
 164         IndexBits::encode(index_.code()) |
 165         LookupModeBits::encode(mode_);
 166   }
 167
 168   class DictionaryBits: public BitField<int, 0, 3> {};
 169   class ResultBits: public BitField<int, 3, 3> {};
 170   class IndexBits: public BitField<int, 6, 3> {};
 171   class LookupModeBits: public BitField<LookupMode, 9, 1> {};
 172
 173   Register dictionary_;
 174   Register result_;
 175   Register index_;
 176   LookupMode mode_;
 177 };
 178
 179
 180 class RecordWriteStub: public PlatformCodeStub {
 181  public:
 182   RecordWriteStub(Isolate* isolate,
 183                   Register object,
 184                   Register value,
 185                   Register address,
 186                   RememberedSetAction remembered_set_action,
 187                   SaveFPRegsMode fp_mode)
 188       : PlatformCodeStub(isolate),
 189         object_(object),
 190         value_(value),
 191         address_(address),
 192         remembered_set_action_(remembered_set_action),
 193         save_fp_regs_mode_(fp_mode),
 194         regs_(object,   // An input reg.
 195               address,  // An input reg.
 196               value) {  // One scratch reg.
 197   }
 198
 199   enum Mode {
 200     STORE_BUFFER_ONLY,
 201     INCREMENTAL,
 202     INCREMENTAL_COMPACTION
 203   };
 204
 205   virtual bool SometimesSetsUpAFrame() { return false; }
 206
 207   static const byte kTwoByteNopInstruction = 0x3c;  // Cmpb al, #imm8.
 208   static const byte kTwoByteJumpInstruction = 0xeb;  // Jmp #imm8.
 209
 210   static const byte kFiveByteNopInstruction = 0x3d;  // Cmpl eax, #imm32.
 211   static const byte kFiveByteJumpInstruction = 0xe9;  // Jmp #imm32.
 212
 213   static Mode GetMode(Code* stub) {
 214     byte first_instruction = stub->instruction_start()[0];
 215     byte second_instruction = stub->instruction_start()[2];
 216
 217     if (first_instruction == kTwoByteJumpInstruction) {
 218       return INCREMENTAL;
 219     }
 220
 221     DCHECK(first_instruction == kTwoByteNopInstruction);
 222
 223     if (second_instruction == kFiveByteJumpInstruction) {
 224       return INCREMENTAL_COMPACTION;
 225     }
 226
 227     DCHECK(second_instruction == kFiveByteNopInstruction);
 228
 229     return STORE_BUFFER_ONLY;
 230   }
 231
 232   static void Patch(Code* stub, Mode mode) {
 233     switch (mode) {
 234       case STORE_BUFFER_ONLY:
 235         DCHECK(GetMode(stub) == INCREMENTAL ||
 236                GetMode(stub) == INCREMENTAL_COMPACTION);
 237         stub->instruction_start()[0] = kTwoByteNopInstruction;
 238         stub->instruction_start()[2] = kFiveByteNopInstruction;
 239         break;
 240       case INCREMENTAL:
 241         DCHECK(GetMode(stub) == STORE_BUFFER_ONLY);
 242         stub->instruction_start()[0] = kTwoByteJumpInstruction;
 243         break;
 244       case INCREMENTAL_COMPACTION:
 245         DCHECK(GetMode(stub) == STORE_BUFFER_ONLY);
 246         stub->instruction_start()[0] = kTwoByteNopInstruction;
 247         stub->instruction_start()[2] = kFiveByteJumpInstruction;
 248         break;
 249     }
 250     DCHECK(GetMode(stub) == mode);
 251     CpuFeatures::FlushICache(stub->instruction_start(), 7);
 252   }
 253
 254  private:
 255   // This is a helper class for freeing up 3 scratch registers, where the third
 256   // is always ecx (needed for shift operations).  The input is two registers
 257   // that must be preserved and one scratch register provided by the caller.
 258   class RegisterAllocation {
 259    public:
 260     RegisterAllocation(Register object,
 261                        Register address,
 262                        Register scratch0)
 263         : object_orig_(object),
 264           address_orig_(address),
 265           scratch0_orig_(scratch0),
 266           object_(object),
 267           address_(address),
 268           scratch0_(scratch0) {
 269       DCHECK(!AreAliased(scratch0, object, address, no_reg));
 270       scratch1_ = GetRegThatIsNotEcxOr(object_, address_, scratch0_);
 271       if (scratch0.is(ecx)) {
 272         scratch0_ = GetRegThatIsNotEcxOr(object_, address_, scratch1_);
 273       }
 274       if (object.is(ecx)) {
 275         object_ = GetRegThatIsNotEcxOr(address_, scratch0_, scratch1_);
 276       }
 277       if (address.is(ecx)) {
 278         address_ = GetRegThatIsNotEcxOr(object_, scratch0_, scratch1_);
 279       }
 280       DCHECK(!AreAliased(scratch0_, object_, address_, ecx));
 281     }
 282
 283     void Save(MacroAssembler* masm) {
 284       DCHECK(!address_orig_.is(object_));
 285       DCHECK(object_.is(object_orig_) || address_.is(address_orig_));
 286       DCHECK(!AreAliased(object_, address_, scratch1_, scratch0_));
 287       DCHECK(!AreAliased(object_orig_, address_, scratch1_, scratch0_));
 288       DCHECK(!AreAliased(object_, address_orig_, scratch1_, scratch0_));
 289       // We don't have to save scratch0_orig_ because it was given to us as
 290       // a scratch register.  But if we had to switch to a different reg then
 291       // we should save the new scratch0_.
 292       if (!scratch0_.is(scratch0_orig_)) masm->push(scratch0_);
 293       if (!ecx.is(scratch0_orig_) &&
 294           !ecx.is(object_orig_) &&
 295           !ecx.is(address_orig_)) {
 296         masm->push(ecx);
 297       }
 298       masm->push(scratch1_);
 299       if (!address_.is(address_orig_)) {
 300         masm->push(address_);
 301         masm->mov(address_, address_orig_);
 302       }
 303       if (!object_.is(object_orig_)) {
 304         masm->push(object_);
 305         masm->mov(object_, object_orig_);
 306       }
 307     }
 308
 309     void Restore(MacroAssembler* masm) {
 310       // These will have been preserved the entire time, so we just need to move
 311       // them back.  Only in one case is the orig_ reg different from the plain
 312       // one, since only one of them can alias with ecx.
 313       if (!object_.is(object_orig_)) {
 314         masm->mov(object_orig_, object_);
 315         masm->pop(object_);
 316       }
 317       if (!address_.is(address_orig_)) {
 318         masm->mov(address_orig_, address_);
 319         masm->pop(address_);
 320       }
 321       masm->pop(scratch1_);
 322       if (!ecx.is(scratch0_orig_) &&
 323           !ecx.is(object_orig_) &&
 324           !ecx.is(address_orig_)) {
 325         masm->pop(ecx);
 326       }
 327       if (!scratch0_.is(scratch0_orig_)) masm->pop(scratch0_);
 328     }
 329
 330     // If we have to call into C then we need to save and restore all caller-
 331     // saved registers that were not already preserved.  The caller saved
 332     // registers are eax, ecx and edx.  The three scratch registers (incl. ecx)
 333     // will be restored by other means so we don't bother pushing them here.
 334     void SaveCallerSaveRegisters(MacroAssembler* masm, SaveFPRegsMode mode) {
 335       if (!scratch0_.is(eax) && !scratch1_.is(eax)) masm->push(eax);
 336       if (!scratch0_.is(edx) && !scratch1_.is(edx)) masm->push(edx);
 337       if (mode == kSaveFPRegs) {
 338         masm->sub(esp,
 339                   Immediate(kDoubleSize * (XMMRegister::kMaxNumRegisters - 1)));
 340         // Save all XMM registers except XMM0.
 341         for (int i = XMMRegister::kMaxNumRegisters - 1; i > 0; i--) {
 342           XMMRegister reg = XMMRegister::from_code(i);
 343           masm->movsd(Operand(esp, (i - 1) * kDoubleSize), reg);
 344         }
 345       }
 346     }
 347
 348     inline void RestoreCallerSaveRegisters(MacroAssembler*masm,
 349                                            SaveFPRegsMode mode) {
 350       if (mode == kSaveFPRegs) {
 351         // Restore all XMM registers except XMM0.
 352         for (int i = XMMRegister::kMaxNumRegisters - 1; i > 0; i--) {
 353           XMMRegister reg = XMMRegister::from_code(i);
 354           masm->movsd(reg, Operand(esp, (i - 1) * kDoubleSize));
 355         }
 356         masm->add(esp,
 357                   Immediate(kDoubleSize * (XMMRegister::kMaxNumRegisters - 1)));
 358       }
 359       if (!scratch0_.is(edx) && !scratch1_.is(edx)) masm->pop(edx);
 360       if (!scratch0_.is(eax) && !scratch1_.is(eax)) masm->pop(eax);
 361     }
 362
 363     inline Register object() { return object_; }
 364     inline Register address() { return address_; }
 365     inline Register scratch0() { return scratch0_; }
 366     inline Register scratch1() { return scratch1_; }
 367
 368    private:
 369     Register object_orig_;
 370     Register address_orig_;
 371     Register scratch0_orig_;
 372     Register object_;
 373     Register address_;
 374     Register scratch0_;
 375     Register scratch1_;
 376     // Third scratch register is always ecx.
 377
 378     Register GetRegThatIsNotEcxOr(Register r1,
 379                                   Register r2,
 380                                   Register r3) {
 381       for (int i = 0; i < Register::NumAllocatableRegisters(); i++) {
 382         Register candidate = Register::FromAllocationIndex(i);
 383         if (candidate.is(ecx)) continue;
 384         if (candidate.is(r1)) continue;
 385         if (candidate.is(r2)) continue;
 386         if (candidate.is(r3)) continue;
 387         return candidate;
 388       }
 389       UNREACHABLE();
 390       return no_reg;
 391     }
 392     friend class RecordWriteStub;
 393   };
 394
 395   enum OnNoNeedToInformIncrementalMarker {
 396     kReturnOnNoNeedToInformIncrementalMarker,
 397     kUpdateRememberedSetOnNoNeedToInformIncrementalMarker
 398   }
 399 ;
 400   void Generate(MacroAssembler* masm);
 401   void GenerateIncremental(MacroAssembler* masm, Mode mode);
 402   void CheckNeedsToInformIncrementalMarker(
 403       MacroAssembler* masm,
 404       OnNoNeedToInformIncrementalMarker on_no_need,
 405       Mode mode);
 406   void InformIncrementalMarker(MacroAssembler* masm);
 407
 408   Major MajorKey() const { return RecordWrite; }
 409
 410   int MinorKey() const {
 411     return ObjectBits::encode(object_.code()) |
 412         ValueBits::encode(value_.code()) |
 413         AddressBits::encode(address_.code()) |
 414         RememberedSetActionBits::encode(remembered_set_action_) |
 415         SaveFPRegsModeBits::encode(save_fp_regs_mode_);
 416   }
 417
 418   void Activate(Code* code) {
 419     code->GetHeap()->incremental_marking()->ActivateGeneratedStub(code);
 420   }
 421
 422   class ObjectBits: public BitField<int, 0, 3> {};
 423   class ValueBits: public BitField<int, 3, 3> {};
 424   class AddressBits: public BitField<int, 6, 3> {};
 425   class RememberedSetActionBits: public BitField<RememberedSetAction, 9, 1> {};
 426   class SaveFPRegsModeBits: public BitField<SaveFPRegsMode, 10, 1> {};
 427
 428   Register object_;
 429   Register value_;
 430   Register address_;
 431   RememberedSetAction remembered_set_action_;
 432   SaveFPRegsMode save_fp_regs_mode_;
 433   RegisterAllocation regs_;
 434 };
 435
 436
 437 } }  // namespace v8::internal
 438
 439 #endif  // V8_IA32_CODE_STUBS_IA32_H_