// Copyright (c) 1994-2006 Sun Microsystems Inc.
// All Rights Reserved.
//
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// 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 {
AssemblerOptions AssemblerOptions::Default(
Isolate* isolate, bool explicitly_support_serialization) {
AssemblerOptions 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.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;
}
// -----------------------------------------------------------------------------
// Implementation of AssemblerBase
AssemblerBase::AssemblerBase(const AssemblerOptions& 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;
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);
}
int AssemblerBase::AddCodeTarget(Handle<Code> target) {
int current = static_cast<int>(code_targets_.size());
if (current > 0 && !target.is_null() &&
code_targets_.back().address() == target.address()) {
// Optimization if we keep jumping to the same code target.
return current - 1;
} else {
code_targets_.push_back(target);
return current;
}
}
Handle<Code> AssemblerBase::GetCodeTarget(intptr_t code_target_index) const {
DCHECK_LE(0, code_target_index);
DCHECK_LT(code_target_index, code_targets_.size());
return code_targets_[code_target_index];
}
void AssemblerBase::UpdateCodeTarget(intptr_t code_target_index,
Handle<Code> code) {
DCHECK_LE(0, code_target_index);
DCHECK_LT(code_target_index, code_targets_.size());
code_targets_[code_target_index] = code;
}
} // namespace internal
} // namespace v8