deps/v8/src/x64/code-stubs-x64.h
// 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_X64_CODE_STUBS_X64_H_
#define V8_X64_CODE_STUBS_X64_H_
#include "src/ic-inl.h"
namespace v8 {
namespace internal {
void ArrayNativeCode(MacroAssembler* masm, Label* call_generic_code);
class StoreBufferOverflowStub: public PlatformCodeStub {
public:
StoreBufferOverflowStub(Isolate* isolate, SaveFPRegsMode save_fp)
: PlatformCodeStub(isolate), save_doubles_(save_fp) { }
void Generate(MacroAssembler* masm);
static void GenerateFixedRegStubsAheadOfTime(Isolate* isolate);
virtual bool SometimesSetsUpAFrame() { return false; }
private:
SaveFPRegsMode save_doubles_;
Major MajorKey() const { return StoreBufferOverflow; }
int MinorKey() const { return (save_doubles_ == kSaveFPRegs) ? 1 : 0; }
};
class StringHelper : public AllStatic {
public:
// Generate code for copying characters using the rep movs instruction.
// Copies rcx characters from rsi to rdi. Copying of overlapping regions is
// not supported.
static void GenerateCopyCharacters(MacroAssembler* masm,
Register dest,
Register src,
Register count,
String::Encoding encoding);
// Generate string hash.
static void GenerateHashInit(MacroAssembler* masm,
Register hash,
Register character,
Register scratch);
static void GenerateHashAddCharacter(MacroAssembler* masm,
Register hash,
Register character,
Register scratch);
static void GenerateHashGetHash(MacroAssembler* masm,
Register hash,
Register scratch);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(StringHelper);
};
class SubStringStub: public PlatformCodeStub {
public:
explicit SubStringStub(Isolate* isolate) : PlatformCodeStub(isolate) {}
private:
Major MajorKey() const { return SubString; }
int MinorKey() const { return 0; }
void Generate(MacroAssembler* masm);
};
class StringCompareStub: public PlatformCodeStub {
public:
explicit StringCompareStub(Isolate* isolate) : PlatformCodeStub(isolate) {}
// Compares two flat ASCII strings and returns result in rax.
static void GenerateCompareFlatAsciiStrings(MacroAssembler* masm,
Register left,
Register right,
Register scratch1,
Register scratch2,
Register scratch3,
Register scratch4);
// Compares two flat ASCII strings for equality and returns result
// in rax.
static void GenerateFlatAsciiStringEquals(MacroAssembler* masm,
Register left,
Register right,
Register scratch1,
Register scratch2);
private:
virtual Major MajorKey() const { return StringCompare; }
virtual int MinorKey() const { return 0; }
virtual void Generate(MacroAssembler* masm);
static void GenerateAsciiCharsCompareLoop(
MacroAssembler* masm,
Register left,
Register right,
Register length,
Register scratch,
Label* chars_not_equal,
Label::Distance near_jump = Label::kFar);
};
class NameDictionaryLookupStub: public PlatformCodeStub {
public:
enum LookupMode { POSITIVE_LOOKUP, NEGATIVE_LOOKUP };
NameDictionaryLookupStub(Isolate* isolate,
Register dictionary,
Register result,
Register index,
LookupMode mode)
: PlatformCodeStub(isolate),
dictionary_(dictionary),
result_(result),
index_(index),
mode_(mode) { }
void Generate(MacroAssembler* masm);
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);
virtual bool SometimesSetsUpAFrame() { 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;
Major MajorKey() const { return NameDictionaryLookup; }
int MinorKey() const {
return DictionaryBits::encode(dictionary_.code()) |
ResultBits::encode(result_.code()) |
IndexBits::encode(index_.code()) |
LookupModeBits::encode(mode_);
}
class DictionaryBits: public BitField<int, 0, 4> {};
class ResultBits: public BitField<int, 4, 4> {};
class IndexBits: public BitField<int, 8, 4> {};
class LookupModeBits: public BitField<LookupMode, 12, 1> {};
Register dictionary_;
Register result_;
Register index_;
LookupMode mode_;
};
class RecordWriteStub: public PlatformCodeStub {
public:
RecordWriteStub(Isolate* isolate,
Register object,
Register value,
Register address,
RememberedSetAction remembered_set_action,
SaveFPRegsMode fp_mode)
: PlatformCodeStub(isolate),
object_(object),
value_(value),
address_(address),
remembered_set_action_(remembered_set_action),
save_fp_regs_mode_(fp_mode),
regs_(object, // An input reg.
address, // An input reg.
value) { // One scratch reg.
}
enum Mode {
STORE_BUFFER_ONLY,
INCREMENTAL,
INCREMENTAL_COMPACTION
};
virtual bool SometimesSetsUpAFrame() { 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);
CpuFeatures::FlushICache(stub->instruction_start(), 7);
}
private:
// This is a helper class for freeing up 3 scratch registers, where the third
// is always rcx (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_ = GetRegThatIsNotRcxOr(object_, address_, scratch0_);
if (scratch0.is(rcx)) {
scratch0_ = GetRegThatIsNotRcxOr(object_, address_, scratch1_);
}
if (object.is(rcx)) {
object_ = GetRegThatIsNotRcxOr(address_, scratch0_, scratch1_);
}
if (address.is(rcx)) {
address_ = GetRegThatIsNotRcxOr(object_, scratch0_, scratch1_);
}
DCHECK(!AreAliased(scratch0_, object_, address_, rcx));
}
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 (!rcx.is(scratch0_orig_) &&
!rcx.is(object_orig_) &&
!rcx.is(address_orig_)) {
masm->Push(rcx);
}
masm->Push(scratch1_);
if (!address_.is(address_orig_)) {
masm->Push(address_);
masm->movp(address_, address_orig_);
}
if (!object_.is(object_orig_)) {
masm->Push(object_);
masm->movp(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 rcx.
if (!object_.is(object_orig_)) {
masm->movp(object_orig_, object_);
masm->Pop(object_);
}
if (!address_.is(address_orig_)) {
masm->movp(address_orig_, address_);
masm->Pop(address_);
}
masm->Pop(scratch1_);
if (!rcx.is(scratch0_orig_) &&
!rcx.is(object_orig_) &&
!rcx.is(address_orig_)) {
masm->Pop(rcx);
}
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 three scratch registers (incl. rcx) will be restored by other means
// so we don't bother pushing them here. Rbx, rbp and r12-15 are callee
// save and don't need to be preserved.
void SaveCallerSaveRegisters(MacroAssembler* masm, SaveFPRegsMode mode) {
masm->PushCallerSaved(mode, scratch0_, scratch1_, rcx);
}
inline void RestoreCallerSaveRegisters(MacroAssembler*masm,
SaveFPRegsMode mode) {
masm->PopCallerSaved(mode, scratch0_, scratch1_, rcx);
}
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 rcx.
Register GetRegThatIsNotRcxOr(Register r1,
Register r2,
Register r3) {
for (int i = 0; i < Register::NumAllocatableRegisters(); i++) {
Register candidate = Register::FromAllocationIndex(i);
if (candidate.is(rcx)) 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
};
void Generate(MacroAssembler* masm);
void GenerateIncremental(MacroAssembler* masm, Mode mode);
void CheckNeedsToInformIncrementalMarker(
MacroAssembler* masm,
OnNoNeedToInformIncrementalMarker on_no_need,
Mode mode);
void InformIncrementalMarker(MacroAssembler* masm);
Major MajorKey() const { return RecordWrite; }
int MinorKey() const {
return ObjectBits::encode(object_.code()) |
ValueBits::encode(value_.code()) |
AddressBits::encode(address_.code()) |
RememberedSetActionBits::encode(remembered_set_action_) |
SaveFPRegsModeBits::encode(save_fp_regs_mode_);
}
void Activate(Code* code) {
code->GetHeap()->incremental_marking()->ActivateGeneratedStub(code);
}
class ObjectBits: public BitField<int, 0, 4> {};
class ValueBits: public BitField<int, 4, 4> {};
class AddressBits: public BitField<int, 8, 4> {};
class RememberedSetActionBits: public BitField<RememberedSetAction, 12, 1> {};
class SaveFPRegsModeBits: public BitField<SaveFPRegsMode, 13, 1> {};
Register object_;
Register value_;
Register address_;
RememberedSetAction remembered_set_action_;
SaveFPRegsMode save_fp_regs_mode_;
Label slow_;
RegisterAllocation regs_;
};
} } // namespace v8::internal
#endif // V8_X64_CODE_STUBS_X64_H_