// Copyright (c) 1994-2006 Sun Microsystems Inc.
// 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.
//
// - Redistribution 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 Sun Microsystems or the names of 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.
// The original source code covered by the above license above has been
// modified significantly by Google Inc.
// Copyright 2012 the V8 project authors. All rights reserved.
#include "src/assembler.h"
#include "src/assembler-inl.h"
#include "src/code-stubs.h"
#include "src/deoptimizer.h"
#include "src/disassembler.h"
#include "src/instruction-stream.h"
#include "src/isolate.h"
#include "src/ostreams.h"
#include "src/simulator.h" // For flushing instruction cache.
#include "src/snapshot/serializer-common.h"
#include "src/snapshot/snapshot.h"
namespace v8 {
namespace internal {
const char* const RelocInfo::kFillerCommentString = "DEOPTIMIZATION PADDING";
// -----------------------------------------------------------------------------
// Implementation of AssemblerBase
AssemblerBase::Options AssemblerBase::DefaultOptions(
Isolate* isolate, bool explicitly_support_serialization) {
Options options;
bool serializer =
isolate->serializer_enabled() || explicitly_support_serialization;
options.record_reloc_info_for_serialization = serializer;
options.enable_root_array_delta_access = !serializer;
#ifdef USE_SIMULATOR
// Don't generate simulator specific code if we are building a snapshot, which
// might be run on real hardware.
options.enable_simulator_code = !serializer;
#endif
options.isolate_independent_code = isolate->ShouldLoadConstantsFromRootList();
options.inline_offheap_trampolines = !serializer;
#if V8_TARGET_ARCH_X64 || V8_TARGET_ARCH_ARM64
options.code_range_start =
isolate->heap()->memory_allocator()->code_range()->start();
#endif
return options;
}
AssemblerBase::AssemblerBase(const Options& options, void* buffer,
int buffer_size)
: options_(options),
enabled_cpu_features_(0),
emit_debug_code_(FLAG_debug_code),
predictable_code_size_(false),
constant_pool_available_(false),
jump_optimization_info_(nullptr) {
own_buffer_ = buffer == nullptr;
if (buffer_size == 0) buffer_size = kMinimalBufferSize;
DCHECK_GT(buffer_size, 0);
if (own_buffer_) buffer = NewArray<byte>(buffer_size);
buffer_ = static_cast<byte*>(buffer);
buffer_size_ = buffer_size;
pc_ = buffer_;
}
AssemblerBase::~AssemblerBase() {
if (own_buffer_) DeleteArray(buffer_);
}
void AssemblerBase::FlushICache(void* start, size_t size) {
if (size == 0) return;
#if defined(USE_SIMULATOR)
base::LockGuard<base::Mutex> lock_guard(Simulator::i_cache_mutex());
Simulator::FlushICache(Simulator::i_cache(), start, size);
#else
CpuFeatures::FlushICache(start, size);
#endif // USE_SIMULATOR
}
void AssemblerBase::Print(Isolate* isolate) {
StdoutStream os;
v8::internal::Disassembler::Decode(isolate, &os, buffer_, pc_);
}
// -----------------------------------------------------------------------------
// Implementation of PredictableCodeSizeScope
PredictableCodeSizeScope::PredictableCodeSizeScope(AssemblerBase* assembler,
int expected_size)
: assembler_(assembler),
expected_size_(expected_size),
start_offset_(assembler->pc_offset()),
old_value_(assembler->predictable_code_size()) {
assembler_->set_predictable_code_size(true);
}
PredictableCodeSizeScope::~PredictableCodeSizeScope() {
CHECK_EQ(expected_size_, assembler_->pc_offset() - start_offset_);
assembler_->set_predictable_code_size(old_value_);
}
// -----------------------------------------------------------------------------
// Implementation of CpuFeatureScope
#ifdef DEBUG
CpuFeatureScope::CpuFeatureScope(AssemblerBase* assembler, CpuFeature f,
CheckPolicy check)
: assembler_(assembler) {
DCHECK_IMPLIES(check == kCheckSupported, CpuFeatures::IsSupported(f));
old_enabled_ = assembler_->enabled_cpu_features();
assembler_->EnableCpuFeature(f);
}
CpuFeatureScope::~CpuFeatureScope() {
assembler_->set_enabled_cpu_features(old_enabled_);
}
#endif
bool CpuFeatures::initialized_ = false;
unsigned CpuFeatures::supported_ = 0;
unsigned CpuFeatures::icache_line_size_ = 0;
unsigned CpuFeatures::dcache_line_size_ = 0;
// -----------------------------------------------------------------------------
// Implementation of RelocInfoWriter and RelocIterator
//
// Relocation information is written backwards in memory, from high addresses
// towards low addresses, byte by byte. Therefore, in the encodings listed
// below, the first byte listed it at the highest address, and successive
// bytes in the record are at progressively lower addresses.
//
// Encoding
//
// The most common modes are given single-byte encodings. Also, it is
// easy to identify the type of reloc info and skip unwanted modes in
// an iteration.
//
// The encoding relies on the fact that there are fewer than 14
// different relocation modes using standard non-compact encoding.
//
// The first byte of a relocation record has a tag in its low 2 bits:
// Here are the record schemes, depending on the low tag and optional higher
// tags.
//
// Low tag:
// 00: embedded_object: [6-bit pc delta] 00
//
// 01: code_target: [6-bit pc delta] 01
//
// 10: wasm_stub_call: [6-bit pc delta] 10
//
// 11: long_record [6 bit reloc mode] 11
// followed by pc delta
// followed by optional data depending on type.
//
// If a pc delta exceeds 6 bits, it is split into a remainder that fits into
// 6 bits and a part that does not. The latter is encoded as a long record
// with PC_JUMP as pseudo reloc info mode. The former is encoded as part of
// the following record in the usual way. The long pc jump record has variable
// length:
// pc-jump: [PC_JUMP] 11
// [7 bits data] 0
// ...
// [7 bits data] 1
// (Bits 6..31 of pc delta, with leading zeroes
// dropped, and last non-zero chunk tagged with 1.)
const int kTagBits = 2;
const int kTagMask = (1 << kTagBits) - 1;
const int kLongTagBits = 6;
const int kEmbeddedObjectTag = 0;
const int kCodeTargetTag = 1;
const int kWasmStubCallTag = 2;
const int kDefaultTag = 3;
const int kSmallPCDeltaBits = kBitsPerByte - kTagBits;
const int kSmallPCDeltaMask = (1 << kSmallPCDeltaBits) - 1;
const int RelocInfo::kMaxSmallPCDelta = kSmallPCDeltaMask;
const int kChunkBits = 7;
const int kChunkMask = (1 << kChunkBits) - 1;
const int kLastChunkTagBits = 1;
const int kLastChunkTagMask = 1;
const int kLastChunkTag = 1;
uint32_t RelocInfoWriter::WriteLongPCJump(uint32_t pc_delta) {
// Return if the pc_delta can fit in kSmallPCDeltaBits bits.
// Otherwise write a variable length PC jump for the bits that do
// not fit in the kSmallPCDeltaBits bits.
if (is_uintn(pc_delta, kSmallPCDeltaBits)) return pc_delta;
WriteMode(RelocInfo::PC_JUMP);
uint32_t pc_jump = pc_delta >> kSmallPCDeltaBits;
DCHECK_GT(pc_jump, 0);
// Write kChunkBits size chunks of the pc_jump.
for (; pc_jump > 0; pc_jump = pc_jump >> kChunkBits) {
byte b = pc_jump & kChunkMask;
*--pos_ = b << kLastChunkTagBits;
}
// Tag the last chunk so it can be identified.
*pos_ = *pos_ | kLastChunkTag;
// Return the remaining kSmallPCDeltaBits of the pc_delta.
return pc_delta & kSmallPCDeltaMask;
}
void RelocInfoWriter::WriteShortTaggedPC(uint32_t pc_delta, int tag) {
// Write a byte of tagged pc-delta, possibly preceded by an explicit pc-jump.
pc_delta = WriteLongPCJump(pc_delta);
*--pos_ = pc_delta << kTagBits | tag;
}
void RelocInfoWriter::WriteShortData(intptr_t data_delta) {
*--pos_ = static_cast<byte>(data_delta);
}
void RelocInfoWriter::WriteMode(RelocInfo::Mode rmode) {
STATIC_ASSERT(RelocInfo::NUMBER_OF_MODES <= (1 << kLongTagBits));
*--pos_ = static_cast<int>((rmode << kTagBits) | kDefaultTag);
}
void RelocInfoWriter::WriteModeAndPC(uint32_t pc_delta, RelocInfo::Mode rmode) {
// Write two-byte tagged pc-delta, possibly preceded by var. length pc-jump.
pc_delta = WriteLongPCJump(pc_delta);
WriteMode(rmode);
*--pos_ = pc_delta;
}
void RelocInfoWriter::WriteIntData(int number) {
for (int i = 0; i < kIntSize; i++) {
*--pos_ = static_cast<byte>(number);
// Signed right shift is arithmetic shift. Tested in test-utils.cc.
number = number >> kBitsPerByte;
}
}
void RelocInfoWriter::WriteData(intptr_t data_delta) {
for (int i = 0; i < kIntptrSize; i++) {
*--pos_ = static_cast<byte>(data_delta);
// Signed right shift is arithmetic shift. Tested in test-utils.cc.
data_delta = data_delta >> kBitsPerByte;
}
}
void RelocInfoWriter::Write(const RelocInfo* rinfo) {
RelocInfo::Mode rmode = rinfo->rmode();
#ifdef DEBUG
byte* begin_pos = pos_;
#endif
DCHECK(rinfo->rmode() < RelocInfo::NUMBER_OF_MODES);
DCHECK_GE(rinfo->pc() - reinterpret_cast<Address>(last_pc_), 0);
// Use unsigned delta-encoding for pc.
uint32_t pc_delta =
static_cast<uint32_t>(rinfo->pc() - reinterpret_cast<Address>(last_pc_));
// The two most common modes are given small tags, and usually fit in a byte.
if (rmode == RelocInfo::EMBEDDED_OBJECT) {
WriteShortTaggedPC(pc_delta, kEmbeddedObjectTag);
} else if (rmode == RelocInfo::CODE_TARGET) {
WriteShortTaggedPC(pc_delta, kCodeTargetTag);
DCHECK_LE(begin_pos - pos_, RelocInfo::kMaxCallSize);
} else if (rmode == RelocInfo::WASM_STUB_CALL) {
WriteShortTaggedPC(pc_delta, kWasmStubCallTag);
} else {
WriteModeAndPC(pc_delta, rmode);
if (RelocInfo::IsComment(rmode)) {
WriteData(rinfo->data());
} else if (RelocInfo::IsDeoptReason(rmode)) {
DCHECK_LT(rinfo->data(), 1 << kBitsPerByte);
WriteShortData(rinfo->data());
} else if (RelocInfo::IsConstPool(rmode) ||
RelocInfo::IsVeneerPool(rmode) || RelocInfo::IsDeoptId(rmode) ||
RelocInfo::IsDeoptPosition(rmode)) {
WriteIntData(static_cast<int>(rinfo->data()));
}
}
last_pc_ = reinterpret_cast<byte*>(rinfo->pc());
#ifdef DEBUG
DCHECK_LE(begin_pos - pos_, kMaxSize);
#endif
}
inline int RelocIterator::AdvanceGetTag() {
return *--pos_ & kTagMask;
}
inline RelocInfo::Mode RelocIterator::GetMode() {
return static_cast<RelocInfo::Mode>((*pos_ >> kTagBits) &
((1 << kLongTagBits) - 1));
}
inline void RelocIterator::ReadShortTaggedPC() {
rinfo_.pc_ += *pos_ >> kTagBits;
}
inline void RelocIterator::AdvanceReadPC() {
rinfo_.pc_ += *--pos_;
}
void RelocIterator::AdvanceReadInt() {
int x = 0;
for (int i = 0; i < kIntSize; i++) {
x |= static_cast<int>(*--pos_) << i * kBitsPerByte;
}
rinfo_.data_ = x;
}
void RelocIterator::AdvanceReadData() {
intptr_t x = 0;
for (int i = 0; i < kIntptrSize; i++) {
x |= static_cast<intptr_t>(*--pos_) << i * kBitsPerByte;
}
rinfo_.data_ = x;
}
void RelocIterator::AdvanceReadLongPCJump() {
// Read the 32-kSmallPCDeltaBits most significant bits of the
// pc jump in kChunkBits bit chunks and shift them into place.
// Stop when the last chunk is encountered.
uint32_t pc_jump = 0;
for (int i = 0; i < kIntSize; i++) {
byte pc_jump_part = *--pos_;
pc_jump |= (pc_jump_part >> kLastChunkTagBits) << i * kChunkBits;
if ((pc_jump_part & kLastChunkTagMask) == 1) break;
}
// The least significant kSmallPCDeltaBits bits will be added
// later.
rinfo_.pc_ += pc_jump << kSmallPCDeltaBits;
}
inline void RelocIterator::ReadShortData() {
uint8_t unsigned_b = *pos_;
rinfo_.data_ = unsigned_b;
}
void RelocIterator::next() {
DCHECK(!done());
// Basically, do the opposite of RelocInfoWriter::Write.
// Reading of data is as far as possible avoided for unwanted modes,
// but we must always update the pc.
//
// We exit this loop by returning when we find a mode we want.
while (pos_ > end_) {
int tag = AdvanceGetTag();
if (tag == kEmbeddedObjectTag) {
ReadShortTaggedPC();
if (SetMode(RelocInfo::EMBEDDED_OBJECT)) return;
} else if (tag == kCodeTargetTag) {
ReadShortTaggedPC();
if (SetMode(RelocInfo::CODE_TARGET)) return;
} else if (tag == kWasmStubCallTag) {
ReadShortTaggedPC();
if (SetMode(RelocInfo::WASM_STUB_CALL)) return;
} else {
DCHECK_EQ(tag, kDefaultTag);
RelocInfo::Mode rmode = GetMode();
if (rmode == RelocInfo::PC_JUMP) {
AdvanceReadLongPCJump();
} else {
AdvanceReadPC();
if (RelocInfo::IsComment(rmode)) {
if (SetMode(rmode)) {
AdvanceReadData();
return;
}
Advance(kIntptrSize);
} else if (RelocInfo::IsDeoptReason(rmode)) {
Advance();
if (SetMode(rmode)) {
ReadShortData();
return;
}
} else if (RelocInfo::IsConstPool(rmode) ||
RelocInfo::IsVeneerPool(rmode) ||
RelocInfo::IsDeoptId(rmode) ||
RelocInfo::IsDeoptPosition(rmode)) {
if (SetMode(rmode)) {
AdvanceReadInt();
return;
}
Advance(kIntSize);
} else if (SetMode(static_cast<RelocInfo::Mode>(rmode))) {
return;
}
}
}
}
done_ = true;
}
RelocIterator::RelocIterator(Code* code, int mode_mask)
: RelocIterator(code, code->raw_instruction_start(), code->constant_pool(),
code->relocation_end(), code->relocation_start(),
mode_mask) {}
RelocIterator::RelocIterator(const CodeReference code_reference, int mode_mask)
: RelocIterator(nullptr, code_reference.instruction_start(),
code_reference.constant_pool(),
code_reference.relocation_end(),
code_reference.relocation_start(), mode_mask) {}
#ifdef V8_EMBEDDED_BUILTINS
RelocIterator::RelocIterator(EmbeddedData* embedded_data, Code* code,
int mode_mask)
: RelocIterator(
code, embedded_data->InstructionStartOfBuiltin(code->builtin_index()),
code->constant_pool(),
code->relocation_start() + code->relocation_size(),
code->relocation_start(), mode_mask) {}
#endif // V8_EMBEDDED_BUILTINS
RelocIterator::RelocIterator(const CodeDesc& desc, int mode_mask)
: RelocIterator(nullptr, reinterpret_cast<Address>(desc.buffer), 0,
desc.buffer + desc.buffer_size,
desc.buffer + desc.buffer_size - desc.reloc_size,
mode_mask) {}
RelocIterator::RelocIterator(Vector<byte> instructions,
Vector<const byte> reloc_info, Address const_pool,
int mode_mask)
: RelocIterator(nullptr, reinterpret_cast<Address>(instructions.start()),
const_pool, reloc_info.start() + reloc_info.size(),
reloc_info.start(), mode_mask) {}
RelocIterator::RelocIterator(Code* host, Address pc, Address constant_pool,
const byte* pos, const byte* end, int mode_mask)
: pos_(pos), end_(end), mode_mask_(mode_mask) {
// Relocation info is read backwards.
DCHECK_GE(pos_, end_);
rinfo_.host_ = host;
rinfo_.pc_ = pc;
rinfo_.constant_pool_ = constant_pool;
if (mode_mask_ == 0) pos_ = end_;
next();
}
// -----------------------------------------------------------------------------
// Implementation of RelocInfo
// static
bool RelocInfo::OffHeapTargetIsCodedSpecially() {
#if defined(V8_TARGET_ARCH_ARM) || defined(V8_TARGET_ARCH_ARM64) || \
defined(V8_TARGET_ARCH_X64) || defined(V8_TARGET_ARCH_IA32)
return false;
#elif defined(V8_TARGET_ARCH_MIPS) || defined(V8_TARGET_ARCH_MIPS64) || \
defined(V8_TARGET_ARCH_PPC) || defined(V8_TARGET_ARCH_S390)
return true;
#endif
}
Address RelocInfo::wasm_call_address() const {
DCHECK_EQ(rmode_, WASM_CALL);
return Assembler::target_address_at(pc_, constant_pool_);
}
void RelocInfo::set_wasm_call_address(Address address,
ICacheFlushMode icache_flush_mode) {
DCHECK_EQ(rmode_, WASM_CALL);
Assembler::set_target_address_at(pc_, constant_pool_, address,
icache_flush_mode);
}
Address RelocInfo::wasm_stub_call_address() const {
DCHECK_EQ(rmode_, WASM_STUB_CALL);
return Assembler::target_address_at(pc_, constant_pool_);
}
void RelocInfo::set_wasm_stub_call_address(Address address,
ICacheFlushMode icache_flush_mode) {
DCHECK_EQ(rmode_, WASM_STUB_CALL);
Assembler::set_target_address_at(pc_, constant_pool_, address,
icache_flush_mode);
}
void RelocInfo::set_target_address(Address target,
WriteBarrierMode write_barrier_mode,
ICacheFlushMode icache_flush_mode) {
DCHECK(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_) || IsWasmCall(rmode_));
Assembler::set_target_address_at(pc_, constant_pool_, target,
icache_flush_mode);
if (write_barrier_mode == UPDATE_WRITE_BARRIER && host() != nullptr &&
IsCodeTarget(rmode_)) {
Code* target_code = Code::GetCodeFromTargetAddress(target);
host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(host(), this,
target_code);
}
}
#ifdef DEBUG
bool RelocInfo::RequiresRelocation(const CodeDesc& desc) {
// Ensure there are no code targets or embedded objects present in the
// deoptimization entries, they would require relocation after code
// generation.
int mode_mask = RelocInfo::ModeMask(RelocInfo::CODE_TARGET) |
RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) |
RelocInfo::kApplyMask;
RelocIterator it(desc, mode_mask);
return !it.done();
}
#endif
#ifdef ENABLE_DISASSEMBLER
const char* RelocInfo::RelocModeName(RelocInfo::Mode rmode) {
switch (rmode) {
case NONE:
return "no reloc";
case EMBEDDED_OBJECT:
return "embedded object";
case CODE_TARGET:
return "code target";
case RUNTIME_ENTRY:
return "runtime entry";
case COMMENT:
return "comment";
case EXTERNAL_REFERENCE:
return "external reference";
case INTERNAL_REFERENCE:
return "internal reference";
case INTERNAL_REFERENCE_ENCODED:
return "encoded internal reference";
case OFF_HEAP_TARGET:
return "off heap target";
case DEOPT_SCRIPT_OFFSET:
return "deopt script offset";
case DEOPT_INLINING_ID:
return "deopt inlining id";
case DEOPT_REASON:
return "deopt reason";
case DEOPT_ID:
return "deopt index";
case CONST_POOL:
return "constant pool";
case VENEER_POOL:
return "veneer pool";
case WASM_CALL:
return "internal wasm call";
case WASM_STUB_CALL:
return "wasm stub call";
case JS_TO_WASM_CALL:
return "js to wasm call";
case NUMBER_OF_MODES:
case PC_JUMP:
UNREACHABLE();
}
return "unknown relocation type";
}
void RelocInfo::Print(Isolate* isolate, std::ostream& os) { // NOLINT
os << reinterpret_cast<const void*>(pc_) << " " << RelocModeName(rmode_);
if (IsComment(rmode_)) {
os << " (" << reinterpret_cast<char*>(data_) << ")";
} else if (rmode_ == DEOPT_SCRIPT_OFFSET || rmode_ == DEOPT_INLINING_ID) {
os << " (" << data() << ")";
} else if (rmode_ == DEOPT_REASON) {
os << " ("
<< DeoptimizeReasonToString(static_cast<DeoptimizeReason>(data_)) << ")";
} else if (rmode_ == EMBEDDED_OBJECT) {
os << " (" << Brief(target_object()) << ")";
} else if (rmode_ == EXTERNAL_REFERENCE) {
if (isolate) {
ExternalReferenceEncoder ref_encoder(isolate);
os << " ("
<< ref_encoder.NameOfAddress(isolate, target_external_reference())
<< ") ";
}
os << " (" << reinterpret_cast<const void*>(target_external_reference())
<< ")";
} else if (IsCodeTarget(rmode_)) {
const Address code_target = target_address();
Code* code = Code::GetCodeFromTargetAddress(code_target);
DCHECK(code->IsCode());
os << " (" << Code::Kind2String(code->kind());
if (Builtins::IsBuiltin(code)) {
os << " " << Builtins::name(code->builtin_index());
} else if (code->kind() == Code::STUB) {
os << " " << CodeStub::MajorName(CodeStub::GetMajorKey(code));
}
os << ") (" << reinterpret_cast<const void*>(target_address()) << ")";
} else if (IsRuntimeEntry(rmode_) && isolate->deoptimizer_data() != nullptr) {
// Deoptimization bailouts are stored as runtime entries.
DeoptimizeKind type;
if (Deoptimizer::IsDeoptimizationEntry(isolate, target_address(), &type)) {
int id = GetDeoptimizationId(isolate, type);
os << " (" << Deoptimizer::MessageFor(type) << " deoptimization bailout "
<< id << ")";
}
} else if (IsConstPool(rmode_)) {
os << " (size " << static_cast<int>(data_) << ")";
}
os << "\n";
}
#endif // ENABLE_DISASSEMBLER
#ifdef VERIFY_HEAP
void RelocInfo::Verify(Isolate* isolate) {
switch (rmode_) {
case EMBEDDED_OBJECT:
Object::VerifyPointer(target_object());
break;
case CODE_TARGET: {
// convert inline target address to code object
Address addr = target_address();
CHECK_NE(addr, kNullAddress);
// Check that we can find the right code object.
Code* code = Code::GetCodeFromTargetAddress(addr);
Object* found = isolate->FindCodeObject(addr);
CHECK(found->IsCode());
CHECK(code->address() == HeapObject::cast(found)->address());
break;
}
case INTERNAL_REFERENCE:
case INTERNAL_REFERENCE_ENCODED: {
Address target = target_internal_reference();
Address pc = target_internal_reference_address();
Code* code = Code::cast(isolate->FindCodeObject(pc));
CHECK(target >= code->InstructionStart());
CHECK(target <= code->InstructionEnd());
break;
}
case OFF_HEAP_TARGET: {
Address addr = target_off_heap_target();
CHECK_NE(addr, kNullAddress);
CHECK_NOT_NULL(InstructionStream::TryLookupCode(isolate, addr));
break;
}
case RUNTIME_ENTRY:
case COMMENT:
case EXTERNAL_REFERENCE:
case DEOPT_SCRIPT_OFFSET:
case DEOPT_INLINING_ID:
case DEOPT_REASON:
case DEOPT_ID:
case CONST_POOL:
case VENEER_POOL:
case WASM_CALL:
case WASM_STUB_CALL:
case JS_TO_WASM_CALL:
case NONE:
break;
case NUMBER_OF_MODES:
case PC_JUMP:
UNREACHABLE();
break;
}
}
#endif // VERIFY_HEAP
ConstantPoolBuilder::ConstantPoolBuilder(int ptr_reach_bits,
int double_reach_bits) {
info_[ConstantPoolEntry::INTPTR].entries.reserve(64);
info_[ConstantPoolEntry::INTPTR].regular_reach_bits = ptr_reach_bits;
info_[ConstantPoolEntry::DOUBLE].regular_reach_bits = double_reach_bits;
}
ConstantPoolEntry::Access ConstantPoolBuilder::NextAccess(
ConstantPoolEntry::Type type) const {
const PerTypeEntryInfo& info = info_[type];
if (info.overflow()) return ConstantPoolEntry::OVERFLOWED;
int dbl_count = info_[ConstantPoolEntry::DOUBLE].regular_count;
int dbl_offset = dbl_count * kDoubleSize;
int ptr_count = info_[ConstantPoolEntry::INTPTR].regular_count;
int ptr_offset = ptr_count * kPointerSize + dbl_offset;
if (type == ConstantPoolEntry::DOUBLE) {
// Double overflow detection must take into account the reach for both types
int ptr_reach_bits = info_[ConstantPoolEntry::INTPTR].regular_reach_bits;
if (!is_uintn(dbl_offset, info.regular_reach_bits) ||
(ptr_count > 0 &&
!is_uintn(ptr_offset + kDoubleSize - kPointerSize, ptr_reach_bits))) {
return ConstantPoolEntry::OVERFLOWED;
}
} else {
DCHECK(type == ConstantPoolEntry::INTPTR);
if (!is_uintn(ptr_offset, info.regular_reach_bits)) {
return ConstantPoolEntry::OVERFLOWED;
}
}
return ConstantPoolEntry::REGULAR;
}
ConstantPoolEntry::Access ConstantPoolBuilder::AddEntry(
ConstantPoolEntry& entry, ConstantPoolEntry::Type type) {
DCHECK(!emitted_label_.is_bound());
PerTypeEntryInfo& info = info_[type];
const int entry_size = ConstantPoolEntry::size(type);
bool merged = false;
if (entry.sharing_ok()) {
// Try to merge entries
std::vector<ConstantPoolEntry>::iterator it = info.shared_entries.begin();
int end = static_cast<int>(info.shared_entries.size());
for (int i = 0; i < end; i++, it++) {
if ((entry_size == kPointerSize) ? entry.value() == it->value()
: entry.value64() == it->value64()) {
// Merge with found entry.
entry.set_merged_index(i);
merged = true;
break;
}
}
}
// By definition, merged entries have regular access.
DCHECK(!merged || entry.merged_index() < info.regular_count);
ConstantPoolEntry::Access access =
(merged ? ConstantPoolEntry::REGULAR : NextAccess(type));
// Enforce an upper bound on search time by limiting the search to
// unique sharable entries which fit in the regular section.
if (entry.sharing_ok() && !merged && access == ConstantPoolEntry::REGULAR) {
info.shared_entries.push_back(entry);
} else {
info.entries.push_back(entry);
}
// We're done if we found a match or have already triggered the
// overflow state.
if (merged || info.overflow()) return access;
if (access == ConstantPoolEntry::REGULAR) {
info.regular_count++;
} else {
info.overflow_start = static_cast<int>(info.entries.size()) - 1;
}
return access;
}
void ConstantPoolBuilder::EmitSharedEntries(Assembler* assm,
ConstantPoolEntry::Type type) {
PerTypeEntryInfo& info = info_[type];
std::vector<ConstantPoolEntry>& shared_entries = info.shared_entries;
const int entry_size = ConstantPoolEntry::size(type);
int base = emitted_label_.pos();
DCHECK_GT(base, 0);
int shared_end = static_cast<int>(shared_entries.size());
std::vector<ConstantPoolEntry>::iterator shared_it = shared_entries.begin();
for (int i = 0; i < shared_end; i++, shared_it++) {
int offset = assm->pc_offset() - base;
shared_it->set_offset(offset); // Save offset for merged entries.
if (entry_size == kPointerSize) {
assm->dp(shared_it->value());
} else {
assm->dq(shared_it->value64());
}
DCHECK(is_uintn(offset, info.regular_reach_bits));
// Patch load sequence with correct offset.
assm->PatchConstantPoolAccessInstruction(shared_it->position(), offset,
ConstantPoolEntry::REGULAR, type);
}
}
void ConstantPoolBuilder::EmitGroup(Assembler* assm,
ConstantPoolEntry::Access access,
ConstantPoolEntry::Type type) {
PerTypeEntryInfo& info = info_[type];
const bool overflow = info.overflow();
std::vector<ConstantPoolEntry>& entries = info.entries;
std::vector<ConstantPoolEntry>& shared_entries = info.shared_entries;
const int entry_size = ConstantPoolEntry::size(type);
int base = emitted_label_.pos();
DCHECK_GT(base, 0);
int begin;
int end;
if (access == ConstantPoolEntry::REGULAR) {
// Emit any shared entries first
EmitSharedEntries(assm, type);
}
if (access == ConstantPoolEntry::REGULAR) {
begin = 0;
end = overflow ? info.overflow_start : static_cast<int>(entries.size());
} else {
DCHECK(access == ConstantPoolEntry::OVERFLOWED);
if (!overflow) return;
begin = info.overflow_start;
end = static_cast<int>(entries.size());
}
std::vector<ConstantPoolEntry>::iterator it = entries.begin();
if (begin > 0) std::advance(it, begin);
for (int i = begin; i < end; i++, it++) {
// Update constant pool if necessary and get the entry's offset.
int offset;
ConstantPoolEntry::Access entry_access;
if (!it->is_merged()) {
// Emit new entry
offset = assm->pc_offset() - base;
entry_access = access;
if (entry_size == kPointerSize) {
assm->dp(it->value());
} else {
assm->dq(it->value64());
}
} else {
// Retrieve offset from shared entry.
offset = shared_entries[it->merged_index()].offset();
entry_access = ConstantPoolEntry::REGULAR;
}
DCHECK(entry_access == ConstantPoolEntry::OVERFLOWED ||
is_uintn(offset, info.regular_reach_bits));
// Patch load sequence with correct offset.
assm->PatchConstantPoolAccessInstruction(it->position(), offset,
entry_access, type);
}
}
// Emit and return position of pool. Zero implies no constant pool.
int ConstantPoolBuilder::Emit(Assembler* assm) {
bool emitted = emitted_label_.is_bound();
bool empty = IsEmpty();
if (!emitted) {
// Mark start of constant pool. Align if necessary.
if (!empty) assm->DataAlign(kDoubleSize);
assm->bind(&emitted_label_);
if (!empty) {
// Emit in groups based on access and type.
// Emit doubles first for alignment purposes.
EmitGroup(assm, ConstantPoolEntry::REGULAR, ConstantPoolEntry::DOUBLE);
EmitGroup(assm, ConstantPoolEntry::REGULAR, ConstantPoolEntry::INTPTR);
if (info_[ConstantPoolEntry::DOUBLE].overflow()) {
assm->DataAlign(kDoubleSize);
EmitGroup(assm, ConstantPoolEntry::OVERFLOWED,
ConstantPoolEntry::DOUBLE);
}
if (info_[ConstantPoolEntry::INTPTR].overflow()) {
EmitGroup(assm, ConstantPoolEntry::OVERFLOWED,
ConstantPoolEntry::INTPTR);
}
}
}
return !empty ? emitted_label_.pos() : 0;
}
HeapObjectRequest::HeapObjectRequest(double heap_number, int offset)
: kind_(kHeapNumber), offset_(offset) {
value_.heap_number = heap_number;
DCHECK(!IsSmiDouble(value_.heap_number));
}
HeapObjectRequest::HeapObjectRequest(CodeStub* code_stub, int offset)
: kind_(kCodeStub), offset_(offset) {
value_.code_stub = code_stub;
DCHECK_NOT_NULL(value_.code_stub);
}
// Platform specific but identical code for all the platforms.
void Assembler::RecordDeoptReason(DeoptimizeReason reason,
SourcePosition position, int id) {
EnsureSpace ensure_space(this);
RecordRelocInfo(RelocInfo::DEOPT_SCRIPT_OFFSET, position.ScriptOffset());
RecordRelocInfo(RelocInfo::DEOPT_INLINING_ID, position.InliningId());
RecordRelocInfo(RelocInfo::DEOPT_REASON, static_cast<int>(reason));
RecordRelocInfo(RelocInfo::DEOPT_ID, id);
}
void Assembler::RecordComment(const char* msg) {
if (FLAG_code_comments) {
EnsureSpace ensure_space(this);
RecordRelocInfo(RelocInfo::COMMENT, reinterpret_cast<intptr_t>(msg));
}
}
void Assembler::DataAlign(int m) {
DCHECK(m >= 2 && base::bits::IsPowerOfTwo(m));
while ((pc_offset() & (m - 1)) != 0) {
db(0);
}
}
void AssemblerBase::RequestHeapObject(HeapObjectRequest request) {
request.set_offset(pc_offset());
heap_object_requests_.push_front(request);
}
} // namespace internal
} // namespace v8