// Copyright 2011 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef V8_IA32_CODE_STUBS_IA32_H_
#define V8_IA32_CODE_STUBS_IA32_H_
namespace v8 {
namespace internal {
void ArrayNativeCode(MacroAssembler* masm,
bool construct_call,
Label* call_generic_code);
class StringHelper : public AllStatic {
public:
// Generate code for copying characters using the rep movs instruction.
// Copies ecx characters from esi to edi. Copying of overlapping regions is
// not supported.
static void GenerateCopyCharacters(MacroAssembler* masm,
Register dest,
Register src,
Register count,
Register scratch,
String::Encoding encoding);
// 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,
Register left, Register right,
Register scratch1,
Register scratch2);
private:
static void GenerateOneByteCharsCompareLoop(
MacroAssembler* masm, Register left, Register right, Register length,
Register scratch, Label* chars_not_equal,
Label::Distance chars_not_equal_near = Label::kFar);
DISALLOW_IMPLICIT_CONSTRUCTORS(StringHelper);
};
class NameDictionaryLookupStub: public PlatformCodeStub {
public:
enum LookupMode { POSITIVE_LOOKUP, NEGATIVE_LOOKUP };
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);
}
static void GenerateNegativeLookup(MacroAssembler* masm,
Label* miss,
Label* done,
Register properties,
Handle<Name> name,
Register r0);
static void GeneratePositiveLookup(MacroAssembler* masm,
Label* miss,
Label* done,
Register elements,
Register name,
Register r0,
Register r1);
bool SometimesSetsUpAFrame() override { return false; }
private:
static const int kInlinedProbes = 4;
static const int kTotalProbes = 20;
static const int kCapacityOffset =
NameDictionary::kHeaderSize +
NameDictionary::kCapacityIndex * kPointerSize;
static const int kElementsStartOffset =
NameDictionary::kHeaderSize +
NameDictionary::kElementsStartIndex * kPointerSize;
Register dictionary() const {
return Register::from_code(DictionaryBits::decode(minor_key_));
}
Register result() const {
return Register::from_code(ResultBits::decode(minor_key_));
}
Register index() const {
return Register::from_code(IndexBits::decode(minor_key_));
}
LookupMode mode() const { return LookupModeBits::decode(minor_key_); }
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> {};
DEFINE_NULL_CALL_INTERFACE_DESCRIPTOR();
DEFINE_PLATFORM_CODE_STUB(NameDictionaryLookup, PlatformCodeStub);
};
class RecordWriteStub: public PlatformCodeStub {
public:
RecordWriteStub(Isolate* isolate,
Register object,
Register value,
Register address,
RememberedSetAction remembered_set_action,
SaveFPRegsMode fp_mode)
: PlatformCodeStub(isolate),
regs_(object, // An input reg.
address, // An input reg.
value) { // One scratch reg.
minor_key_ = ObjectBits::encode(object.code()) |
ValueBits::encode(value.code()) |
AddressBits::encode(address.code()) |
RememberedSetActionBits::encode(remembered_set_action) |
SaveFPRegsModeBits::encode(fp_mode);
}
RecordWriteStub(uint32_t key, Isolate* isolate)
: PlatformCodeStub(key, isolate), regs_(object(), address(), value()) {}
enum Mode {
STORE_BUFFER_ONLY,
INCREMENTAL,
INCREMENTAL_COMPACTION
};
bool SometimesSetsUpAFrame() override { return false; }
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.
static Mode GetMode(Code* stub) {
byte first_instruction = stub->instruction_start()[0];
byte second_instruction = stub->instruction_start()[2];
if (first_instruction == kTwoByteJumpInstruction) {
return INCREMENTAL;
}
DCHECK(first_instruction == kTwoByteNopInstruction);
if (second_instruction == kFiveByteJumpInstruction) {
return INCREMENTAL_COMPACTION;
}
DCHECK(second_instruction == kFiveByteNopInstruction);
return STORE_BUFFER_ONLY;
}
static void Patch(Code* stub, Mode mode) {
switch (mode) {
case STORE_BUFFER_ONLY:
DCHECK(GetMode(stub) == INCREMENTAL ||
GetMode(stub) == INCREMENTAL_COMPACTION);
stub->instruction_start()[0] = kTwoByteNopInstruction;
stub->instruction_start()[2] = kFiveByteNopInstruction;
break;
case INCREMENTAL:
DCHECK(GetMode(stub) == STORE_BUFFER_ONLY);
stub->instruction_start()[0] = kTwoByteJumpInstruction;
break;
case INCREMENTAL_COMPACTION:
DCHECK(GetMode(stub) == STORE_BUFFER_ONLY);
stub->instruction_start()[0] = kTwoByteNopInstruction;
stub->instruction_start()[2] = kFiveByteJumpInstruction;
break;
}
DCHECK(GetMode(stub) == mode);
Assembler::FlushICache(stub->GetIsolate(), stub->instruction_start(), 7);
}
DEFINE_NULL_CALL_INTERFACE_DESCRIPTOR();
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:
RegisterAllocation(Register object,
Register address,
Register scratch0)
: object_orig_(object),
address_orig_(address),
scratch0_orig_(scratch0),
object_(object),
address_(address),
scratch0_(scratch0) {
DCHECK(!AreAliased(scratch0, object, address, no_reg));
scratch1_ = GetRegThatIsNotEcxOr(object_, address_, scratch0_);
if (scratch0.is(ecx)) {
scratch0_ = GetRegThatIsNotEcxOr(object_, address_, scratch1_);
}
if (object.is(ecx)) {
object_ = GetRegThatIsNotEcxOr(address_, scratch0_, scratch1_);
}
if (address.is(ecx)) {
address_ = GetRegThatIsNotEcxOr(object_, scratch0_, scratch1_);
}
DCHECK(!AreAliased(scratch0_, object_, address_, ecx));
}
void Save(MacroAssembler* masm) {
DCHECK(!address_orig_.is(object_));
DCHECK(object_.is(object_orig_) || address_.is(address_orig_));
DCHECK(!AreAliased(object_, address_, scratch1_, scratch0_));
DCHECK(!AreAliased(object_orig_, address_, scratch1_, scratch0_));
DCHECK(!AreAliased(object_, address_orig_, scratch1_, scratch0_));
// 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_.
if (!scratch0_.is(scratch0_orig_)) masm->push(scratch0_);
if (!ecx.is(scratch0_orig_) &&
!ecx.is(object_orig_) &&
!ecx.is(address_orig_)) {
masm->push(ecx);
}
masm->push(scratch1_);
if (!address_.is(address_orig_)) {
masm->push(address_);
masm->mov(address_, address_orig_);
}
if (!object_.is(object_orig_)) {
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.
if (!object_.is(object_orig_)) {
masm->mov(object_orig_, object_);
masm->pop(object_);
}
if (!address_.is(address_orig_)) {
masm->mov(address_orig_, address_);
masm->pop(address_);
}
masm->pop(scratch1_);
if (!ecx.is(scratch0_orig_) &&
!ecx.is(object_orig_) &&
!ecx.is(address_orig_)) {
masm->pop(ecx);
}
if (!scratch0_.is(scratch0_orig_)) masm->pop(scratch0_);
}
// 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) {
masm->PushCallerSaved(mode, ecx, scratch0_, scratch1_);
}
inline void RestoreCallerSaveRegisters(MacroAssembler* masm,
SaveFPRegsMode mode) {
masm->PopCallerSaved(mode, ecx, scratch0_, scratch1_);
}
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) {
for (int i = 0; i < Register::kNumRegisters; i++) {
if (RegisterConfiguration::Crankshaft()->IsAllocatableGeneralCode(i)) {
Register candidate = Register::from_code(i);
if (candidate.is(ecx)) continue;
if (candidate.is(r1)) continue;
if (candidate.is(r2)) continue;
if (candidate.is(r3)) continue;
return candidate;
}
}
UNREACHABLE();
return no_reg;
}
friend class RecordWriteStub;
};
enum OnNoNeedToInformIncrementalMarker {
kReturnOnNoNeedToInformIncrementalMarker,
kUpdateRememberedSetOnNoNeedToInformIncrementalMarker
};
inline Major MajorKey() const final { return RecordWrite; }
void Generate(MacroAssembler* masm) override;
void GenerateIncremental(MacroAssembler* masm, Mode mode);
void CheckNeedsToInformIncrementalMarker(
MacroAssembler* masm,
OnNoNeedToInformIncrementalMarker on_no_need,
Mode mode);
void InformIncrementalMarker(MacroAssembler* masm);
void Activate(Code* code) override {
code->GetHeap()->incremental_marking()->ActivateGeneratedStub(code);
}
Register object() const {
return Register::from_code(ObjectBits::decode(minor_key_));
}
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_);
}
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_;
DISALLOW_COPY_AND_ASSIGN(RecordWriteStub);
};
} // namespace internal
} // namespace v8
#endif // V8_IA32_CODE_STUBS_IA32_H_