// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "v8.h"
#if defined(V8_TARGET_ARCH_ARM)
#include "codegen.h"
#include "macro-assembler.h"
#include "simulator-arm.h"
namespace v8 {
namespace internal {
UnaryMathFunction CreateTranscendentalFunction(TranscendentalCache::Type type) {
switch (type) {
case TranscendentalCache::SIN: return &sin;
case TranscendentalCache::COS: return &cos;
case TranscendentalCache::TAN: return &tan;
case TranscendentalCache::LOG: return &log;
default: UNIMPLEMENTED();
}
return NULL;
}
#define __ masm.
#if defined(USE_SIMULATOR)
byte* fast_exp_arm_machine_code = NULL;
double fast_exp_simulator(double x) {
return Simulator::current(Isolate::Current())->CallFP(
fast_exp_arm_machine_code, x, 0);
}
#endif
UnaryMathFunction CreateExpFunction() {
if (!CpuFeatures::IsSupported(VFP2)) return &exp;
if (!FLAG_fast_math) return &exp;
size_t actual_size;
byte* buffer = static_cast<byte*>(OS::Allocate(1 * KB, &actual_size, true));
if (buffer == NULL) return &exp;
ExternalReference::InitializeMathExpData();
MacroAssembler masm(NULL, buffer, static_cast<int>(actual_size));
{
CpuFeatureScope use_vfp(&masm, VFP2);
DwVfpRegister input = d0;
DwVfpRegister result = d1;
DwVfpRegister double_scratch1 = d2;
DwVfpRegister double_scratch2 = d3;
Register temp1 = r4;
Register temp2 = r5;
Register temp3 = r6;
if (masm.use_eabi_hardfloat()) {
// Input value is in d0 anyway, nothing to do.
} else {
__ vmov(input, r0, r1);
}
__ Push(temp3, temp2, temp1);
MathExpGenerator::EmitMathExp(
&masm, input, result, double_scratch1, double_scratch2,
temp1, temp2, temp3);
__ Pop(temp3, temp2, temp1);
if (masm.use_eabi_hardfloat()) {
__ vmov(d0, result);
} else {
__ vmov(r0, r1, result);
}
__ Ret();
}
CodeDesc desc;
masm.GetCode(&desc);
ASSERT(!RelocInfo::RequiresRelocation(desc));
CPU::FlushICache(buffer, actual_size);
OS::ProtectCode(buffer, actual_size);
#if !defined(USE_SIMULATOR)
return FUNCTION_CAST<UnaryMathFunction>(buffer);
#else
fast_exp_arm_machine_code = buffer;
return &fast_exp_simulator;
#endif
}
#undef __
UnaryMathFunction CreateSqrtFunction() {
return &sqrt;
}
// -------------------------------------------------------------------------
// Platform-specific RuntimeCallHelper functions.
void StubRuntimeCallHelper::BeforeCall(MacroAssembler* masm) const {
masm->EnterFrame(StackFrame::INTERNAL);
ASSERT(!masm->has_frame());
masm->set_has_frame(true);
}
void StubRuntimeCallHelper::AfterCall(MacroAssembler* masm) const {
masm->LeaveFrame(StackFrame::INTERNAL);
ASSERT(masm->has_frame());
masm->set_has_frame(false);
}
// -------------------------------------------------------------------------
// Code generators
#define __ ACCESS_MASM(masm)
void ElementsTransitionGenerator::GenerateMapChangeElementsTransition(
MacroAssembler* masm, AllocationSiteMode mode,
Label* allocation_site_info_found) {
// ----------- S t a t e -------------
// -- r0 : value
// -- r1 : key
// -- r2 : receiver
// -- lr : return address
// -- r3 : target map, scratch for subsequent call
// -- r4 : scratch (elements)
// -----------------------------------
if (mode == TRACK_ALLOCATION_SITE) {
ASSERT(allocation_site_info_found != NULL);
__ TestJSArrayForAllocationSiteInfo(r2, r4);
__ b(eq, allocation_site_info_found);
}
// Set transitioned map.
__ str(r3, FieldMemOperand(r2, HeapObject::kMapOffset));
__ RecordWriteField(r2,
HeapObject::kMapOffset,
r3,
r9,
kLRHasNotBeenSaved,
kDontSaveFPRegs,
EMIT_REMEMBERED_SET,
OMIT_SMI_CHECK);
}
void ElementsTransitionGenerator::GenerateSmiToDouble(
MacroAssembler* masm, AllocationSiteMode mode, Label* fail) {
// ----------- S t a t e -------------
// -- r0 : value
// -- r1 : key
// -- r2 : receiver
// -- lr : return address
// -- r3 : target map, scratch for subsequent call
// -- r4 : scratch (elements)
// -----------------------------------
Label loop, entry, convert_hole, gc_required, only_change_map, done;
bool vfp2_supported = CpuFeatures::IsSupported(VFP2);
if (mode == TRACK_ALLOCATION_SITE) {
__ TestJSArrayForAllocationSiteInfo(r2, r4);
__ b(eq, fail);
}
// Check for empty arrays, which only require a map transition and no changes
// to the backing store.
__ ldr(r4, FieldMemOperand(r2, JSObject::kElementsOffset));
__ CompareRoot(r4, Heap::kEmptyFixedArrayRootIndex);
__ b(eq, &only_change_map);
__ push(lr);
__ ldr(r5, FieldMemOperand(r4, FixedArray::kLengthOffset));
// r4: source FixedArray
// r5: number of elements (smi-tagged)
// Allocate new FixedDoubleArray.
// Use lr as a temporary register.
__ mov(lr, Operand(r5, LSL, 2));
__ add(lr, lr, Operand(FixedDoubleArray::kHeaderSize));
__ AllocateInNewSpace(lr, r6, r7, r9, &gc_required, DOUBLE_ALIGNMENT);
// r6: destination FixedDoubleArray, not tagged as heap object.
// Set destination FixedDoubleArray's length and map.
__ LoadRoot(r9, Heap::kFixedDoubleArrayMapRootIndex);
__ str(r5, MemOperand(r6, FixedDoubleArray::kLengthOffset));
// Update receiver's map.
__ str(r9, MemOperand(r6, HeapObject::kMapOffset));
__ str(r3, FieldMemOperand(r2, HeapObject::kMapOffset));
__ RecordWriteField(r2,
HeapObject::kMapOffset,
r3,
r9,
kLRHasBeenSaved,
kDontSaveFPRegs,
OMIT_REMEMBERED_SET,
OMIT_SMI_CHECK);
// Replace receiver's backing store with newly created FixedDoubleArray.
__ add(r3, r6, Operand(kHeapObjectTag));
__ str(r3, FieldMemOperand(r2, JSObject::kElementsOffset));
__ RecordWriteField(r2,
JSObject::kElementsOffset,
r3,
r9,
kLRHasBeenSaved,
kDontSaveFPRegs,
EMIT_REMEMBERED_SET,
OMIT_SMI_CHECK);
// Prepare for conversion loop.
__ add(r3, r4, Operand(FixedArray::kHeaderSize - kHeapObjectTag));
__ add(r7, r6, Operand(FixedDoubleArray::kHeaderSize));
__ add(r6, r7, Operand(r5, LSL, 2));
__ mov(r4, Operand(kHoleNanLower32));
__ mov(r5, Operand(kHoleNanUpper32));
// r3: begin of source FixedArray element fields, not tagged
// r4: kHoleNanLower32
// r5: kHoleNanUpper32
// r6: end of destination FixedDoubleArray, not tagged
// r7: begin of FixedDoubleArray element fields, not tagged
if (!vfp2_supported) __ Push(r1, r0);
__ b(&entry);
__ bind(&only_change_map);
__ str(r3, FieldMemOperand(r2, HeapObject::kMapOffset));
__ RecordWriteField(r2,
HeapObject::kMapOffset,
r3,
r9,
kLRHasNotBeenSaved,
kDontSaveFPRegs,
OMIT_REMEMBERED_SET,
OMIT_SMI_CHECK);
__ b(&done);
// Call into runtime if GC is required.
__ bind(&gc_required);
__ pop(lr);
__ b(fail);
// Convert and copy elements.
__ bind(&loop);
__ ldr(r9, MemOperand(r3, 4, PostIndex));
// r9: current element
__ UntagAndJumpIfNotSmi(r9, r9, &convert_hole);
// Normal smi, convert to double and store.
if (vfp2_supported) {
CpuFeatureScope scope(masm, VFP2);
__ vmov(s0, r9);
__ vcvt_f64_s32(d0, s0);
__ vstr(d0, r7, 0);
__ add(r7, r7, Operand(8));
} else {
FloatingPointHelper::ConvertIntToDouble(masm,
r9,
FloatingPointHelper::kCoreRegisters,
d0,
r0,
r1,
lr,
s0);
__ Strd(r0, r1, MemOperand(r7, 8, PostIndex));
}
__ b(&entry);
// Hole found, store the-hole NaN.
__ bind(&convert_hole);
if (FLAG_debug_code) {
// Restore a "smi-untagged" heap object.
__ SmiTag(r9);
__ orr(r9, r9, Operand(1));
__ CompareRoot(r9, Heap::kTheHoleValueRootIndex);
__ Assert(eq, "object found in smi-only array");
}
__ Strd(r4, r5, MemOperand(r7, 8, PostIndex));
__ bind(&entry);
__ cmp(r7, r6);
__ b(lt, &loop);
if (!vfp2_supported) __ Pop(r1, r0);
__ pop(lr);
__ bind(&done);
}
void ElementsTransitionGenerator::GenerateDoubleToObject(
MacroAssembler* masm, AllocationSiteMode mode, Label* fail) {
// ----------- S t a t e -------------
// -- r0 : value
// -- r1 : key
// -- r2 : receiver
// -- lr : return address
// -- r3 : target map, scratch for subsequent call
// -- r4 : scratch (elements)
// -----------------------------------
Label entry, loop, convert_hole, gc_required, only_change_map;
if (mode == TRACK_ALLOCATION_SITE) {
__ TestJSArrayForAllocationSiteInfo(r2, r4);
__ b(eq, fail);
}
// Check for empty arrays, which only require a map transition and no changes
// to the backing store.
__ ldr(r4, FieldMemOperand(r2, JSObject::kElementsOffset));
__ CompareRoot(r4, Heap::kEmptyFixedArrayRootIndex);
__ b(eq, &only_change_map);
__ push(lr);
__ Push(r3, r2, r1, r0);
__ ldr(r5, FieldMemOperand(r4, FixedArray::kLengthOffset));
// r4: source FixedDoubleArray
// r5: number of elements (smi-tagged)
// Allocate new FixedArray.
__ mov(r0, Operand(FixedDoubleArray::kHeaderSize));
__ add(r0, r0, Operand(r5, LSL, 1));
__ AllocateInNewSpace(r0, r6, r7, r9, &gc_required, NO_ALLOCATION_FLAGS);
// r6: destination FixedArray, not tagged as heap object
// Set destination FixedDoubleArray's length and map.
__ LoadRoot(r9, Heap::kFixedArrayMapRootIndex);
__ str(r5, MemOperand(r6, FixedDoubleArray::kLengthOffset));
__ str(r9, MemOperand(r6, HeapObject::kMapOffset));
// Prepare for conversion loop.
__ add(r4, r4, Operand(FixedDoubleArray::kHeaderSize - kHeapObjectTag + 4));
__ add(r3, r6, Operand(FixedArray::kHeaderSize));
__ add(r6, r6, Operand(kHeapObjectTag));
__ add(r5, r3, Operand(r5, LSL, 1));
__ LoadRoot(r7, Heap::kTheHoleValueRootIndex);
__ LoadRoot(r9, Heap::kHeapNumberMapRootIndex);
// Using offsetted addresses in r4 to fully take advantage of post-indexing.
// r3: begin of destination FixedArray element fields, not tagged
// r4: begin of source FixedDoubleArray element fields, not tagged, +4
// r5: end of destination FixedArray, not tagged
// r6: destination FixedArray
// r7: the-hole pointer
// r9: heap number map
__ b(&entry);
// Call into runtime if GC is required.
__ bind(&gc_required);
__ Pop(r3, r2, r1, r0);
__ pop(lr);
__ b(fail);
__ bind(&loop);
__ ldr(r1, MemOperand(r4, 8, PostIndex));
// lr: current element's upper 32 bit
// r4: address of next element's upper 32 bit
__ cmp(r1, Operand(kHoleNanUpper32));
__ b(eq, &convert_hole);
// Non-hole double, copy value into a heap number.
__ AllocateHeapNumber(r2, r0, lr, r9, &gc_required);
// r2: new heap number
__ ldr(r0, MemOperand(r4, 12, NegOffset));
__ Strd(r0, r1, FieldMemOperand(r2, HeapNumber::kValueOffset));
__ mov(r0, r3);
__ str(r2, MemOperand(r3, 4, PostIndex));
__ RecordWrite(r6,
r0,
r2,
kLRHasBeenSaved,
kDontSaveFPRegs,
EMIT_REMEMBERED_SET,
OMIT_SMI_CHECK);
__ b(&entry);
// Replace the-hole NaN with the-hole pointer.
__ bind(&convert_hole);
__ str(r7, MemOperand(r3, 4, PostIndex));
__ bind(&entry);
__ cmp(r3, r5);
__ b(lt, &loop);
__ Pop(r3, r2, r1, r0);
// Replace receiver's backing store with newly created and filled FixedArray.
__ str(r6, FieldMemOperand(r2, JSObject::kElementsOffset));
__ RecordWriteField(r2,
JSObject::kElementsOffset,
r6,
r9,
kLRHasBeenSaved,
kDontSaveFPRegs,
EMIT_REMEMBERED_SET,
OMIT_SMI_CHECK);
__ pop(lr);
__ bind(&only_change_map);
// Update receiver's map.
__ str(r3, FieldMemOperand(r2, HeapObject::kMapOffset));
__ RecordWriteField(r2,
HeapObject::kMapOffset,
r3,
r9,
kLRHasNotBeenSaved,
kDontSaveFPRegs,
OMIT_REMEMBERED_SET,
OMIT_SMI_CHECK);
}
void StringCharLoadGenerator::Generate(MacroAssembler* masm,
Register string,
Register index,
Register result,
Label* call_runtime) {
// Fetch the instance type of the receiver into result register.
__ ldr(result, FieldMemOperand(string, HeapObject::kMapOffset));
__ ldrb(result, FieldMemOperand(result, Map::kInstanceTypeOffset));
// We need special handling for indirect strings.
Label check_sequential;
__ tst(result, Operand(kIsIndirectStringMask));
__ b(eq, &check_sequential);
// Dispatch on the indirect string shape: slice or cons.
Label cons_string;
__ tst(result, Operand(kSlicedNotConsMask));
__ b(eq, &cons_string);
// Handle slices.
Label indirect_string_loaded;
__ ldr(result, FieldMemOperand(string, SlicedString::kOffsetOffset));
__ ldr(string, FieldMemOperand(string, SlicedString::kParentOffset));
__ add(index, index, Operand(result, ASR, kSmiTagSize));
__ jmp(&indirect_string_loaded);
// Handle cons strings.
// Check whether the right hand side is the empty string (i.e. if
// this is really a flat string in a cons string). If that is not
// the case we would rather go to the runtime system now to flatten
// the string.
__ bind(&cons_string);
__ ldr(result, FieldMemOperand(string, ConsString::kSecondOffset));
__ CompareRoot(result, Heap::kempty_stringRootIndex);
__ b(ne, call_runtime);
// Get the first of the two strings and load its instance type.
__ ldr(string, FieldMemOperand(string, ConsString::kFirstOffset));
__ bind(&indirect_string_loaded);
__ ldr(result, FieldMemOperand(string, HeapObject::kMapOffset));
__ ldrb(result, FieldMemOperand(result, Map::kInstanceTypeOffset));
// Distinguish sequential and external strings. Only these two string
// representations can reach here (slices and flat cons strings have been
// reduced to the underlying sequential or external string).
Label external_string, check_encoding;
__ bind(&check_sequential);
STATIC_ASSERT(kSeqStringTag == 0);
__ tst(result, Operand(kStringRepresentationMask));
__ b(ne, &external_string);
// Prepare sequential strings
STATIC_ASSERT(SeqTwoByteString::kHeaderSize == SeqOneByteString::kHeaderSize);
__ add(string,
string,
Operand(SeqTwoByteString::kHeaderSize - kHeapObjectTag));
__ jmp(&check_encoding);
// Handle external strings.
__ bind(&external_string);
if (FLAG_debug_code) {
// Assert that we do not have a cons or slice (indirect strings) here.
// Sequential strings have already been ruled out.
__ tst(result, Operand(kIsIndirectStringMask));
__ Assert(eq, "external string expected, but not found");
}
// Rule out short external strings.
STATIC_CHECK(kShortExternalStringTag != 0);
__ tst(result, Operand(kShortExternalStringMask));
__ b(ne, call_runtime);
__ ldr(string, FieldMemOperand(string, ExternalString::kResourceDataOffset));
Label ascii, done;
__ bind(&check_encoding);
STATIC_ASSERT(kTwoByteStringTag == 0);
__ tst(result, Operand(kStringEncodingMask));
__ b(ne, &ascii);
// Two-byte string.
__ ldrh(result, MemOperand(string, index, LSL, 1));
__ jmp(&done);
__ bind(&ascii);
// Ascii string.
__ ldrb(result, MemOperand(string, index));
__ bind(&done);
}
void SeqStringSetCharGenerator::Generate(MacroAssembler* masm,
String::Encoding encoding,
Register string,
Register index,
Register value) {
if (FLAG_debug_code) {
__ tst(index, Operand(kSmiTagMask));
__ Check(eq, "Non-smi index");
__ tst(value, Operand(kSmiTagMask));
__ Check(eq, "Non-smi value");
__ ldr(ip, FieldMemOperand(string, String::kLengthOffset));
__ cmp(index, ip);
__ Check(lt, "Index is too large");
__ cmp(index, Operand(Smi::FromInt(0)));
__ Check(ge, "Index is negative");
__ ldr(ip, FieldMemOperand(string, HeapObject::kMapOffset));
__ ldrb(ip, FieldMemOperand(ip, Map::kInstanceTypeOffset));
__ and_(ip, ip, Operand(kStringRepresentationMask | kStringEncodingMask));
static const uint32_t one_byte_seq_type = kSeqStringTag | kOneByteStringTag;
static const uint32_t two_byte_seq_type = kSeqStringTag | kTwoByteStringTag;
__ cmp(ip, Operand(encoding == String::ONE_BYTE_ENCODING
? one_byte_seq_type : two_byte_seq_type));
__ Check(eq, "Unexpected string type");
}
__ add(ip,
string,
Operand(SeqString::kHeaderSize - kHeapObjectTag));
__ SmiUntag(value, value);
STATIC_ASSERT(kSmiTagSize == 1 && kSmiTag == 0);
if (encoding == String::ONE_BYTE_ENCODING) {
// Smis are tagged by left shift by 1, thus LSR by 1 to smi-untag inline.
__ strb(value, MemOperand(ip, index, LSR, 1));
} else {
// No need to untag a smi for two-byte addressing.
__ strh(value, MemOperand(ip, index));
}
}
static MemOperand ExpConstant(int index, Register base) {
return MemOperand(base, index * kDoubleSize);
}
void MathExpGenerator::EmitMathExp(MacroAssembler* masm,
DwVfpRegister input,
DwVfpRegister result,
DwVfpRegister double_scratch1,
DwVfpRegister double_scratch2,
Register temp1,
Register temp2,
Register temp3) {
ASSERT(!input.is(result));
ASSERT(!input.is(double_scratch1));
ASSERT(!input.is(double_scratch2));
ASSERT(!result.is(double_scratch1));
ASSERT(!result.is(double_scratch2));
ASSERT(!double_scratch1.is(double_scratch2));
ASSERT(!temp1.is(temp2));
ASSERT(!temp1.is(temp3));
ASSERT(!temp2.is(temp3));
ASSERT(ExternalReference::math_exp_constants(0).address() != NULL);
Label done;
__ mov(temp3, Operand(ExternalReference::math_exp_constants(0)));
__ vldr(double_scratch1, ExpConstant(0, temp3));
__ vmov(result, kDoubleRegZero);
__ VFPCompareAndSetFlags(double_scratch1, input);
__ b(ge, &done);
__ vldr(double_scratch2, ExpConstant(1, temp3));
__ VFPCompareAndSetFlags(input, double_scratch2);
__ vldr(result, ExpConstant(2, temp3));
__ b(ge, &done);
__ vldr(double_scratch1, ExpConstant(3, temp3));
__ vldr(result, ExpConstant(4, temp3));
__ vmul(double_scratch1, double_scratch1, input);
__ vadd(double_scratch1, double_scratch1, result);
__ vmov(temp2, temp1, double_scratch1);
__ vsub(double_scratch1, double_scratch1, result);
__ vldr(result, ExpConstant(6, temp3));
__ vldr(double_scratch2, ExpConstant(5, temp3));
__ vmul(double_scratch1, double_scratch1, double_scratch2);
__ vsub(double_scratch1, double_scratch1, input);
__ vsub(result, result, double_scratch1);
__ vmul(input, double_scratch1, double_scratch1);
__ vmul(result, result, input);
__ mov(temp1, Operand(temp2, LSR, 11));
__ vldr(double_scratch2, ExpConstant(7, temp3));
__ vmul(result, result, double_scratch2);
__ vsub(result, result, double_scratch1);
__ vldr(double_scratch2, ExpConstant(8, temp3));
__ vadd(result, result, double_scratch2);
__ movw(ip, 0x7ff);
__ and_(temp2, temp2, Operand(ip));
__ add(temp1, temp1, Operand(0x3ff));
__ mov(temp1, Operand(temp1, LSL, 20));
// Must not call ExpConstant() after overwriting temp3!
__ mov(temp3, Operand(ExternalReference::math_exp_log_table()));
__ ldr(ip, MemOperand(temp3, temp2, LSL, 3));
__ add(temp3, temp3, Operand(kPointerSize));
__ ldr(temp2, MemOperand(temp3, temp2, LSL, 3));
__ orr(temp1, temp1, temp2);
__ vmov(input, ip, temp1);
__ vmul(result, result, input);
__ bind(&done);
}
#undef __
// add(r0, pc, Operand(-8))
static const uint32_t kCodeAgePatchFirstInstruction = 0xe24f0008;
static byte* GetNoCodeAgeSequence(uint32_t* length) {
// The sequence of instructions that is patched out for aging code is the
// following boilerplate stack-building prologue that is found in FUNCTIONS
static bool initialized = false;
static uint32_t sequence[kNoCodeAgeSequenceLength];
byte* byte_sequence = reinterpret_cast<byte*>(sequence);
*length = kNoCodeAgeSequenceLength * Assembler::kInstrSize;
if (!initialized) {
CodePatcher patcher(byte_sequence, kNoCodeAgeSequenceLength);
PredictableCodeSizeScope scope(patcher.masm(), *length);
patcher.masm()->stm(db_w, sp, r1.bit() | cp.bit() | fp.bit() | lr.bit());
patcher.masm()->LoadRoot(ip, Heap::kUndefinedValueRootIndex);
patcher.masm()->add(fp, sp, Operand(2 * kPointerSize));
initialized = true;
}
return byte_sequence;
}
bool Code::IsYoungSequence(byte* sequence) {
uint32_t young_length;
byte* young_sequence = GetNoCodeAgeSequence(&young_length);
bool result = !memcmp(sequence, young_sequence, young_length);
ASSERT(result ||
Memory::uint32_at(sequence) == kCodeAgePatchFirstInstruction);
return result;
}
void Code::GetCodeAgeAndParity(byte* sequence, Age* age,
MarkingParity* parity) {
if (IsYoungSequence(sequence)) {
*age = kNoAge;
*parity = NO_MARKING_PARITY;
} else {
Address target_address = Memory::Address_at(
sequence + Assembler::kInstrSize * (kNoCodeAgeSequenceLength - 1));
Code* stub = GetCodeFromTargetAddress(target_address);
GetCodeAgeAndParity(stub, age, parity);
}
}
void Code::PatchPlatformCodeAge(byte* sequence,
Code::Age age,
MarkingParity parity) {
uint32_t young_length;
byte* young_sequence = GetNoCodeAgeSequence(&young_length);
if (age == kNoAge) {
memcpy(sequence, young_sequence, young_length);
CPU::FlushICache(sequence, young_length);
} else {
Code* stub = GetCodeAgeStub(age, parity);
CodePatcher patcher(sequence, young_length / Assembler::kInstrSize);
patcher.masm()->add(r0, pc, Operand(-8));
patcher.masm()->ldr(pc, MemOperand(pc, -4));
patcher.masm()->dd(reinterpret_cast<uint32_t>(stub->instruction_start()));
}
}
} } // namespace v8::internal
#endif // V8_TARGET_ARCH_ARM