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deoptimizer.cc
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deoptimizer.cc
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// Copyright 2013 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.
#include "src/deoptimizer/deoptimizer.h"
#include <memory>
#include "src/ast/prettyprinter.h"
#include "src/builtins/accessors.h"
#include "src/codegen/assembler-inl.h"
#include "src/codegen/callable.h"
#include "src/codegen/macro-assembler.h"
#include "src/codegen/register-configuration.h"
#include "src/diagnostics/disasm.h"
#include "src/execution/frames-inl.h"
#include "src/execution/pointer-authentication.h"
#include "src/execution/v8threads.h"
#include "src/handles/global-handles.h"
#include "src/heap/heap-inl.h"
#include "src/init/v8.h"
#include "src/interpreter/interpreter.h"
#include "src/logging/counters.h"
#include "src/logging/log.h"
#include "src/objects/debug-objects-inl.h"
#include "src/objects/heap-number-inl.h"
#include "src/objects/smi.h"
#include "src/tracing/trace-event.h"
// Has to be the last include (doesn't have include guards)
#include "src/objects/object-macros.h"
namespace v8 {
namespace internal {
// {FrameWriter} offers a stack writer abstraction for writing
// FrameDescriptions. The main service the class provides is managing
// {top_offset_}, i.e. the offset of the next slot to write to.
class FrameWriter {
public:
static const int NO_INPUT_INDEX = -1;
FrameWriter(Deoptimizer* deoptimizer, FrameDescription* frame,
CodeTracer::Scope* trace_scope)
: deoptimizer_(deoptimizer),
frame_(frame),
trace_scope_(trace_scope),
top_offset_(frame->GetFrameSize()) {}
void PushRawValue(intptr_t value, const char* debug_hint) {
PushValue(value);
if (trace_scope_ != nullptr) {
DebugPrintOutputValue(value, debug_hint);
}
}
void PushRawObject(Object obj, const char* debug_hint) {
intptr_t value = obj.ptr();
PushValue(value);
if (trace_scope_ != nullptr) {
DebugPrintOutputObject(obj, top_offset_, debug_hint);
}
}
void PushCallerPc(intptr_t pc) {
top_offset_ -= kPCOnStackSize;
frame_->SetCallerPc(top_offset_, pc);
DebugPrintOutputValue(pc, "caller's pc\n");
}
void PushCallerFp(intptr_t fp) {
top_offset_ -= kFPOnStackSize;
frame_->SetCallerFp(top_offset_, fp);
DebugPrintOutputValue(fp, "caller's fp\n");
}
void PushCallerConstantPool(intptr_t cp) {
top_offset_ -= kSystemPointerSize;
frame_->SetCallerConstantPool(top_offset_, cp);
DebugPrintOutputValue(cp, "caller's constant_pool\n");
}
void PushTranslatedValue(const TranslatedFrame::iterator& iterator,
const char* debug_hint = "") {
Object obj = iterator->GetRawValue();
PushRawObject(obj, debug_hint);
if (trace_scope_) {
PrintF(trace_scope_->file(), " (input #%d)\n", iterator.input_index());
}
deoptimizer_->QueueValueForMaterialization(output_address(top_offset_), obj,
iterator);
}
unsigned top_offset() const { return top_offset_; }
private:
void PushValue(intptr_t value) {
CHECK_GE(top_offset_, 0);
top_offset_ -= kSystemPointerSize;
frame_->SetFrameSlot(top_offset_, value);
}
Address output_address(unsigned output_offset) {
Address output_address =
static_cast<Address>(frame_->GetTop()) + output_offset;
return output_address;
}
void DebugPrintOutputValue(intptr_t value, const char* debug_hint = "") {
if (trace_scope_ != nullptr) {
PrintF(trace_scope_->file(),
" " V8PRIxPTR_FMT ": [top + %3d] <- " V8PRIxPTR_FMT " ; %s",
output_address(top_offset_), top_offset_, value, debug_hint);
}
}
void DebugPrintOutputObject(Object obj, unsigned output_offset,
const char* debug_hint = "") {
if (trace_scope_ != nullptr) {
PrintF(trace_scope_->file(), " " V8PRIxPTR_FMT ": [top + %3d] <- ",
output_address(output_offset), output_offset);
if (obj.IsSmi()) {
PrintF(trace_scope_->file(), V8PRIxPTR_FMT " <Smi %d>", obj.ptr(),
Smi::cast(obj).value());
} else {
obj.ShortPrint(trace_scope_->file());
}
PrintF(trace_scope_->file(), " ; %s", debug_hint);
}
}
Deoptimizer* deoptimizer_;
FrameDescription* frame_;
CodeTracer::Scope* trace_scope_;
unsigned top_offset_;
};
DeoptimizerData::DeoptimizerData(Heap* heap) : heap_(heap), current_(nullptr) {
Code* start = &deopt_entry_code_[0];
Code* end = &deopt_entry_code_[DeoptimizerData::kLastDeoptimizeKind + 1];
heap_->RegisterStrongRoots(FullObjectSlot(start), FullObjectSlot(end));
}
DeoptimizerData::~DeoptimizerData() {
Code* start = &deopt_entry_code_[0];
heap_->UnregisterStrongRoots(FullObjectSlot(start));
}
Code DeoptimizerData::deopt_entry_code(DeoptimizeKind kind) {
return deopt_entry_code_[static_cast<int>(kind)];
}
void DeoptimizerData::set_deopt_entry_code(DeoptimizeKind kind, Code code) {
deopt_entry_code_[static_cast<int>(kind)] = code;
}
Code Deoptimizer::FindDeoptimizingCode(Address addr) {
if (function_.IsHeapObject()) {
// Search all deoptimizing code in the native context of the function.
Isolate* isolate = isolate_;
NativeContext native_context = function_.context().native_context();
Object element = native_context.DeoptimizedCodeListHead();
while (!element.IsUndefined(isolate)) {
Code code = Code::cast(element);
CHECK(code.kind() == Code::OPTIMIZED_FUNCTION);
if (code.contains(addr)) return code;
element = code.next_code_link();
}
}
return Code();
}
// We rely on this function not causing a GC. It is called from generated code
// without having a real stack frame in place.
Deoptimizer* Deoptimizer::New(Address raw_function, DeoptimizeKind kind,
unsigned bailout_id, Address from,
int fp_to_sp_delta, Isolate* isolate) {
JSFunction function = JSFunction::cast(Object(raw_function));
Deoptimizer* deoptimizer = new Deoptimizer(isolate, function, kind,
bailout_id, from, fp_to_sp_delta);
CHECK_NULL(isolate->deoptimizer_data()->current_);
isolate->deoptimizer_data()->current_ = deoptimizer;
return deoptimizer;
}
Deoptimizer* Deoptimizer::Grab(Isolate* isolate) {
Deoptimizer* result = isolate->deoptimizer_data()->current_;
CHECK_NOT_NULL(result);
result->DeleteFrameDescriptions();
isolate->deoptimizer_data()->current_ = nullptr;
return result;
}
DeoptimizedFrameInfo* Deoptimizer::DebuggerInspectableFrame(
JavaScriptFrame* frame, int jsframe_index, Isolate* isolate) {
CHECK(frame->is_optimized());
TranslatedState translated_values(frame);
translated_values.Prepare(frame->fp());
TranslatedState::iterator frame_it = translated_values.end();
int counter = jsframe_index;
for (auto it = translated_values.begin(); it != translated_values.end();
it++) {
if (it->kind() == TranslatedFrame::kInterpretedFunction ||
it->kind() == TranslatedFrame::kJavaScriptBuiltinContinuation ||
it->kind() ==
TranslatedFrame::kJavaScriptBuiltinContinuationWithCatch) {
if (counter == 0) {
frame_it = it;
break;
}
counter--;
}
}
CHECK(frame_it != translated_values.end());
// We only include kJavaScriptBuiltinContinuation frames above to get the
// counting right.
CHECK_EQ(frame_it->kind(), TranslatedFrame::kInterpretedFunction);
DeoptimizedFrameInfo* info =
new DeoptimizedFrameInfo(&translated_values, frame_it, isolate);
return info;
}
namespace {
class ActivationsFinder : public ThreadVisitor {
public:
explicit ActivationsFinder(std::set<Code>* codes, Code topmost_optimized_code,
bool safe_to_deopt_topmost_optimized_code)
: codes_(codes) {
#ifdef DEBUG
topmost_ = topmost_optimized_code;
safe_to_deopt_ = safe_to_deopt_topmost_optimized_code;
#endif
}
// Find the frames with activations of codes marked for deoptimization, search
// for the trampoline to the deoptimizer call respective to each code, and use
// it to replace the current pc on the stack.
void VisitThread(Isolate* isolate, ThreadLocalTop* top) override {
for (StackFrameIterator it(isolate, top); !it.done(); it.Advance()) {
if (it.frame()->type() == StackFrame::OPTIMIZED) {
Code code = it.frame()->LookupCode();
if (code.kind() == Code::OPTIMIZED_FUNCTION &&
code.marked_for_deoptimization()) {
codes_->erase(code);
// Obtain the trampoline to the deoptimizer call.
SafepointEntry safepoint = code.GetSafepointEntry(it.frame()->pc());
int trampoline_pc = safepoint.trampoline_pc();
DCHECK_IMPLIES(code == topmost_, safe_to_deopt_);
CHECK_GE(trampoline_pc, 0);
// Replace the current pc on the stack with the trampoline.
// TODO(v8:10026): avoid replacing a signed pointer.
Address* pc_addr = it.frame()->pc_address();
Address new_pc = code.raw_instruction_start() + trampoline_pc;
PointerAuthentication::ReplacePC(pc_addr, new_pc, kSystemPointerSize);
}
}
}
}
private:
std::set<Code>* codes_;
#ifdef DEBUG
Code topmost_;
bool safe_to_deopt_;
#endif
};
} // namespace
// Move marked code from the optimized code list to the deoptimized code list,
// and replace pc on the stack for codes marked for deoptimization.
void Deoptimizer::DeoptimizeMarkedCodeForContext(NativeContext native_context) {
DisallowHeapAllocation no_allocation;
Isolate* isolate = native_context.GetIsolate();
Code topmost_optimized_code;
bool safe_to_deopt_topmost_optimized_code = false;
#ifdef DEBUG
// Make sure all activations of optimized code can deopt at their current PC.
// The topmost optimized code has special handling because it cannot be
// deoptimized due to weak object dependency.
for (StackFrameIterator it(isolate, isolate->thread_local_top()); !it.done();
it.Advance()) {
StackFrame::Type type = it.frame()->type();
if (type == StackFrame::OPTIMIZED) {
Code code = it.frame()->LookupCode();
JSFunction function =
static_cast<OptimizedFrame*>(it.frame())->function();
if (FLAG_trace_deopt) {
CodeTracer::Scope scope(isolate->GetCodeTracer());
PrintF(scope.file(), "[deoptimizer found activation of function: ");
function.PrintName(scope.file());
PrintF(scope.file(), " / %" V8PRIxPTR "]\n", function.ptr());
}
SafepointEntry safepoint = code.GetSafepointEntry(it.frame()->pc());
// Turbofan deopt is checked when we are patching addresses on stack.
bool safe_if_deopt_triggered = safepoint.has_deoptimization_index();
bool is_builtin_code = code.kind() == Code::BUILTIN;
DCHECK(topmost_optimized_code.is_null() || safe_if_deopt_triggered ||
is_builtin_code);
if (topmost_optimized_code.is_null()) {
topmost_optimized_code = code;
safe_to_deopt_topmost_optimized_code = safe_if_deopt_triggered;
}
}
}
#endif
// We will use this set to mark those Code objects that are marked for
// deoptimization and have not been found in stack frames.
std::set<Code> codes;
// Move marked code from the optimized code list to the deoptimized code list.
// Walk over all optimized code objects in this native context.
Code prev;
Object element = native_context.OptimizedCodeListHead();
while (!element.IsUndefined(isolate)) {
Code code = Code::cast(element);
CHECK_EQ(code.kind(), Code::OPTIMIZED_FUNCTION);
Object next = code.next_code_link();
if (code.marked_for_deoptimization()) {
codes.insert(code);
if (!prev.is_null()) {
// Skip this code in the optimized code list.
prev.set_next_code_link(next);
} else {
// There was no previous node, the next node is the new head.
native_context.SetOptimizedCodeListHead(next);
}
// Move the code to the _deoptimized_ code list.
code.set_next_code_link(native_context.DeoptimizedCodeListHead());
native_context.SetDeoptimizedCodeListHead(code);
} else {
// Not marked; preserve this element.
prev = code;
}
element = next;
}
ActivationsFinder visitor(&codes, topmost_optimized_code,
safe_to_deopt_topmost_optimized_code);
// Iterate over the stack of this thread.
visitor.VisitThread(isolate, isolate->thread_local_top());
// In addition to iterate over the stack of this thread, we also
// need to consider all the other threads as they may also use
// the code currently beings deoptimized.
isolate->thread_manager()->IterateArchivedThreads(&visitor);
// If there's no activation of a code in any stack then we can remove its
// deoptimization data. We do this to ensure that code objects that are
// unlinked don't transitively keep objects alive unnecessarily.
for (Code code : codes) {
isolate->heap()->InvalidateCodeDeoptimizationData(code);
}
native_context.GetOSROptimizedCodeCache().EvictMarkedCode(
native_context.GetIsolate());
}
void Deoptimizer::DeoptimizeAll(Isolate* isolate) {
RuntimeCallTimerScope runtimeTimer(isolate,
RuntimeCallCounterId::kDeoptimizeCode);
TimerEventScope<TimerEventDeoptimizeCode> timer(isolate);
TRACE_EVENT0("v8", "V8.DeoptimizeCode");
if (FLAG_trace_deopt) {
CodeTracer::Scope scope(isolate->GetCodeTracer());
PrintF(scope.file(), "[deoptimize all code in all contexts]\n");
}
isolate->AbortConcurrentOptimization(BlockingBehavior::kBlock);
DisallowHeapAllocation no_allocation;
// For all contexts, mark all code, then deoptimize.
Object context = isolate->heap()->native_contexts_list();
while (!context.IsUndefined(isolate)) {
NativeContext native_context = NativeContext::cast(context);
MarkAllCodeForContext(native_context);
OSROptimizedCodeCache::Clear(native_context);
DeoptimizeMarkedCodeForContext(native_context);
context = native_context.next_context_link();
}
}
void Deoptimizer::DeoptimizeMarkedCode(Isolate* isolate) {
RuntimeCallTimerScope runtimeTimer(isolate,
RuntimeCallCounterId::kDeoptimizeCode);
TimerEventScope<TimerEventDeoptimizeCode> timer(isolate);
TRACE_EVENT0("v8", "V8.DeoptimizeCode");
if (FLAG_trace_deopt) {
CodeTracer::Scope scope(isolate->GetCodeTracer());
PrintF(scope.file(), "[deoptimize marked code in all contexts]\n");
}
DisallowHeapAllocation no_allocation;
// For all contexts, deoptimize code already marked.
Object context = isolate->heap()->native_contexts_list();
while (!context.IsUndefined(isolate)) {
NativeContext native_context = NativeContext::cast(context);
DeoptimizeMarkedCodeForContext(native_context);
context = native_context.next_context_link();
}
}
void Deoptimizer::MarkAllCodeForContext(NativeContext native_context) {
Object element = native_context.OptimizedCodeListHead();
Isolate* isolate = native_context.GetIsolate();
while (!element.IsUndefined(isolate)) {
Code code = Code::cast(element);
CHECK_EQ(code.kind(), Code::OPTIMIZED_FUNCTION);
code.set_marked_for_deoptimization(true);
element = code.next_code_link();
}
}
void Deoptimizer::DeoptimizeFunction(JSFunction function, Code code) {
Isolate* isolate = function.GetIsolate();
RuntimeCallTimerScope runtimeTimer(isolate,
RuntimeCallCounterId::kDeoptimizeCode);
TimerEventScope<TimerEventDeoptimizeCode> timer(isolate);
TRACE_EVENT0("v8", "V8.DeoptimizeCode");
function.ResetIfBytecodeFlushed();
if (code.is_null()) code = function.code();
if (code.kind() == Code::OPTIMIZED_FUNCTION) {
// Mark the code for deoptimization and unlink any functions that also
// refer to that code. The code cannot be shared across native contexts,
// so we only need to search one.
code.set_marked_for_deoptimization(true);
// The code in the function's optimized code feedback vector slot might
// be different from the code on the function - evict it if necessary.
function.feedback_vector().EvictOptimizedCodeMarkedForDeoptimization(
function.shared(), "unlinking code marked for deopt");
if (!code.deopt_already_counted()) {
code.set_deopt_already_counted(true);
}
DeoptimizeMarkedCodeForContext(function.context().native_context());
// TODO(mythria): Ideally EvictMarkCode should compact the cache without
// having to explicitly call this. We don't do this currently because
// compacting causes GC and DeoptimizeMarkedCodeForContext uses raw
// pointers. Update DeoptimizeMarkedCodeForContext to use handles and remove
// this call from here.
OSROptimizedCodeCache::Compact(
Handle<NativeContext>(function.context().native_context(), isolate));
}
}
void Deoptimizer::ComputeOutputFrames(Deoptimizer* deoptimizer) {
deoptimizer->DoComputeOutputFrames();
}
const char* Deoptimizer::MessageFor(DeoptimizeKind kind) {
switch (kind) {
case DeoptimizeKind::kEager:
return "eager";
case DeoptimizeKind::kSoft:
return "soft";
case DeoptimizeKind::kLazy:
return "lazy";
}
FATAL("Unsupported deopt kind");
return nullptr;
}
namespace {
uint16_t InternalFormalParameterCountWithReceiver(SharedFunctionInfo sfi) {
static constexpr int kTheReceiver = 1;
return sfi.internal_formal_parameter_count() + kTheReceiver;
}
} // namespace
Deoptimizer::Deoptimizer(Isolate* isolate, JSFunction function,
DeoptimizeKind kind, unsigned bailout_id, Address from,
int fp_to_sp_delta)
: isolate_(isolate),
function_(function),
bailout_id_(bailout_id),
deopt_kind_(kind),
from_(from),
fp_to_sp_delta_(fp_to_sp_delta),
deoptimizing_throw_(false),
catch_handler_data_(-1),
catch_handler_pc_offset_(-1),
input_(nullptr),
output_count_(0),
jsframe_count_(0),
output_(nullptr),
caller_frame_top_(0),
caller_fp_(0),
caller_pc_(0),
caller_constant_pool_(0),
input_frame_context_(0),
stack_fp_(0),
trace_scope_(nullptr) {
if (isolate->deoptimizer_lazy_throw()) {
isolate->set_deoptimizer_lazy_throw(false);
deoptimizing_throw_ = true;
}
DCHECK_NE(from, kNullAddress);
compiled_code_ = FindOptimizedCode();
DCHECK(!compiled_code_.is_null());
DCHECK(function.IsJSFunction());
trace_scope_ = FLAG_trace_deopt
? new CodeTracer::Scope(isolate->GetCodeTracer())
: nullptr;
#ifdef DEBUG
DCHECK(AllowHeapAllocation::IsAllowed());
disallow_heap_allocation_ = new DisallowHeapAllocation();
#endif // DEBUG
if ((compiled_code_.kind() != Code::OPTIMIZED_FUNCTION ||
!compiled_code_.deopt_already_counted()) &&
deopt_kind_ == DeoptimizeKind::kSoft) {
isolate->counters()->soft_deopts_executed()->Increment();
}
if (compiled_code_.kind() == Code::OPTIMIZED_FUNCTION) {
compiled_code_.set_deopt_already_counted(true);
HandleScope scope(isolate_);
PROFILE(isolate_, CodeDeoptEvent(handle(compiled_code_, isolate_), kind,
from_, fp_to_sp_delta_));
}
unsigned size = ComputeInputFrameSize();
const int parameter_count =
InternalFormalParameterCountWithReceiver(function.shared());
input_ = new (size) FrameDescription(size, parameter_count);
if (kSupportsFixedDeoptExitSizes) {
DCHECK_EQ(bailout_id_, kMaxUInt32);
// Calculate bailout id from return address.
DCHECK_GT(kNonLazyDeoptExitSize, 0);
DCHECK_GT(kLazyDeoptExitSize, 0);
DeoptimizationData deopt_data =
DeoptimizationData::cast(compiled_code_.deoptimization_data());
Address deopt_start = compiled_code_.raw_instruction_start() +
deopt_data.DeoptExitStart().value();
int non_lazy_deopt_count = deopt_data.NonLazyDeoptCount().value();
Address lazy_deopt_start =
deopt_start + non_lazy_deopt_count * kNonLazyDeoptExitSize;
// The deoptimization exits are sorted so that lazy deopt exits appear last.
static_assert(DeoptimizeKind::kLazy > DeoptimizeKind::kEager,
"lazy deopts are expected to be emitted last");
static_assert(DeoptimizeKind::kLazy > DeoptimizeKind::kSoft,
"lazy deopts are expected to be emitted last");
// from_ is the value of the link register after the call to the
// deoptimizer, so for the last lazy deopt, from_ points to the first
// non-lazy deopt, so we use <=.
if (from_ <= lazy_deopt_start) {
int offset =
static_cast<int>(from_ - kNonLazyDeoptExitSize - deopt_start);
DCHECK_EQ(0, offset % kNonLazyDeoptExitSize);
bailout_id_ = offset / kNonLazyDeoptExitSize;
} else {
int offset =
static_cast<int>(from_ - kLazyDeoptExitSize - lazy_deopt_start);
DCHECK_EQ(0, offset % kLazyDeoptExitSize);
bailout_id_ = non_lazy_deopt_count + (offset / kLazyDeoptExitSize);
}
}
}
Code Deoptimizer::FindOptimizedCode() {
Code compiled_code = FindDeoptimizingCode(from_);
return !compiled_code.is_null() ? compiled_code
: isolate_->FindCodeObject(from_);
}
void Deoptimizer::PrintFunctionName() {
if (function_.IsHeapObject() && function_.IsJSFunction()) {
function_.ShortPrint(trace_scope_->file());
} else {
PrintF(trace_scope_->file(), "%s",
Code::Kind2String(compiled_code_.kind()));
}
}
Handle<JSFunction> Deoptimizer::function() const {
return Handle<JSFunction>(function_, isolate());
}
Handle<Code> Deoptimizer::compiled_code() const {
return Handle<Code>(compiled_code_, isolate());
}
Deoptimizer::~Deoptimizer() {
DCHECK(input_ == nullptr && output_ == nullptr);
DCHECK_NULL(disallow_heap_allocation_);
delete trace_scope_;
}
void Deoptimizer::DeleteFrameDescriptions() {
delete input_;
for (int i = 0; i < output_count_; ++i) {
if (output_[i] != input_) delete output_[i];
}
delete[] output_;
input_ = nullptr;
output_ = nullptr;
#ifdef DEBUG
DCHECK(!AllowHeapAllocation::IsAllowed());
DCHECK_NOT_NULL(disallow_heap_allocation_);
delete disallow_heap_allocation_;
disallow_heap_allocation_ = nullptr;
#endif // DEBUG
}
Address Deoptimizer::GetDeoptimizationEntry(Isolate* isolate,
DeoptimizeKind kind) {
DeoptimizerData* data = isolate->deoptimizer_data();
CHECK_LE(kind, DeoptimizerData::kLastDeoptimizeKind);
CHECK(!data->deopt_entry_code(kind).is_null());
return data->deopt_entry_code(kind).raw_instruction_start();
}
bool Deoptimizer::IsDeoptimizationEntry(Isolate* isolate, Address addr,
DeoptimizeKind type) {
DeoptimizerData* data = isolate->deoptimizer_data();
CHECK_LE(type, DeoptimizerData::kLastDeoptimizeKind);
Code code = data->deopt_entry_code(type);
if (code.is_null()) return false;
return addr == code.raw_instruction_start();
}
bool Deoptimizer::IsDeoptimizationEntry(Isolate* isolate, Address addr,
DeoptimizeKind* type) {
if (IsDeoptimizationEntry(isolate, addr, DeoptimizeKind::kEager)) {
*type = DeoptimizeKind::kEager;
return true;
}
if (IsDeoptimizationEntry(isolate, addr, DeoptimizeKind::kSoft)) {
*type = DeoptimizeKind::kSoft;
return true;
}
if (IsDeoptimizationEntry(isolate, addr, DeoptimizeKind::kLazy)) {
*type = DeoptimizeKind::kLazy;
return true;
}
return false;
}
int Deoptimizer::GetDeoptimizedCodeCount(Isolate* isolate) {
int length = 0;
// Count all entries in the deoptimizing code list of every context.
Object context = isolate->heap()->native_contexts_list();
while (!context.IsUndefined(isolate)) {
NativeContext native_context = NativeContext::cast(context);
Object element = native_context.DeoptimizedCodeListHead();
while (!element.IsUndefined(isolate)) {
Code code = Code::cast(element);
DCHECK(code.kind() == Code::OPTIMIZED_FUNCTION);
if (!code.marked_for_deoptimization()) {
length++;
}
element = code.next_code_link();
}
context = Context::cast(context).next_context_link();
}
return length;
}
namespace {
int LookupCatchHandler(TranslatedFrame* translated_frame, int* data_out) {
switch (translated_frame->kind()) {
case TranslatedFrame::kInterpretedFunction: {
int bytecode_offset = translated_frame->node_id().ToInt();
HandlerTable table(
translated_frame->raw_shared_info().GetBytecodeArray());
return table.LookupRange(bytecode_offset, data_out, nullptr);
}
case TranslatedFrame::kJavaScriptBuiltinContinuationWithCatch: {
return 0;
}
default:
break;
}
return -1;
}
} // namespace
// We rely on this function not causing a GC. It is called from generated code
// without having a real stack frame in place.
void Deoptimizer::DoComputeOutputFrames() {
// When we call this function, the return address of the previous frame has
// been removed from the stack by GenerateDeoptimizationEntries() so the stack
// is not iterable by the SafeStackFrameIterator.
#if V8_TARGET_ARCH_STORES_RETURN_ADDRESS_ON_STACK
DCHECK_EQ(0, isolate()->isolate_data()->stack_is_iterable());
#endif
base::ElapsedTimer timer;
// Determine basic deoptimization information. The optimized frame is
// described by the input data.
DeoptimizationData input_data =
DeoptimizationData::cast(compiled_code_.deoptimization_data());
{
// Read caller's PC, caller's FP and caller's constant pool values
// from input frame. Compute caller's frame top address.
Register fp_reg = JavaScriptFrame::fp_register();
stack_fp_ = input_->GetRegister(fp_reg.code());
caller_frame_top_ = stack_fp_ + ComputeInputFrameAboveFpFixedSize();
Address fp_address = input_->GetFramePointerAddress();
caller_fp_ = Memory<intptr_t>(fp_address);
caller_pc_ =
Memory<intptr_t>(fp_address + CommonFrameConstants::kCallerPCOffset);
// Sign caller_pc_ with caller_frame_top_ to be consistent with everything
// else here.
uint64_t sp = stack_fp_ + StandardFrameConstants::kCallerSPOffset;
// TODO(v8:10026): avoid replacing a signed pointer.
PointerAuthentication::ReplaceContext(
reinterpret_cast<Address*>(&caller_pc_), sp, caller_frame_top_);
input_frame_context_ = Memory<intptr_t>(
fp_address + CommonFrameConstants::kContextOrFrameTypeOffset);
if (FLAG_enable_embedded_constant_pool) {
caller_constant_pool_ = Memory<intptr_t>(
fp_address + CommonFrameConstants::kConstantPoolOffset);
}
}
StackGuard* const stack_guard = isolate()->stack_guard();
CHECK_GT(static_cast<uintptr_t>(caller_frame_top_),
stack_guard->real_jslimit());
if (trace_scope_ != nullptr) {
timer.Start();
PrintF(trace_scope_->file(), "[deoptimizing (DEOPT %s): begin ",
MessageFor(deopt_kind_));
PrintFunctionName();
PrintF(trace_scope_->file(),
" (opt #%d) @%d, FP to SP delta: %d, caller sp: " V8PRIxPTR_FMT
"]\n",
input_data.OptimizationId().value(), bailout_id_, fp_to_sp_delta_,
caller_frame_top_);
if (deopt_kind_ == DeoptimizeKind::kEager ||
deopt_kind_ == DeoptimizeKind::kSoft) {
compiled_code_.PrintDeoptLocation(
trace_scope_->file(), " ;;; deoptimize at ", from_);
}
}
BailoutId node_id = input_data.BytecodeOffset(bailout_id_);
ByteArray translations = input_data.TranslationByteArray();
unsigned translation_index = input_data.TranslationIndex(bailout_id_).value();
TranslationIterator state_iterator(translations, translation_index);
translated_state_.Init(
isolate_, input_->GetFramePointerAddress(), &state_iterator,
input_data.LiteralArray(), input_->GetRegisterValues(),
trace_scope_ == nullptr ? nullptr : trace_scope_->file(),
function_.IsHeapObject()
? function_.shared().internal_formal_parameter_count()
: 0);
// Do the input frame to output frame(s) translation.
size_t count = translated_state_.frames().size();
// If we are supposed to go to the catch handler, find the catching frame
// for the catch and make sure we only deoptimize upto that frame.
if (deoptimizing_throw_) {
size_t catch_handler_frame_index = count;
for (size_t i = count; i-- > 0;) {
catch_handler_pc_offset_ = LookupCatchHandler(
&(translated_state_.frames()[i]), &catch_handler_data_);
if (catch_handler_pc_offset_ >= 0) {
catch_handler_frame_index = i;
break;
}
}
CHECK_LT(catch_handler_frame_index, count);
count = catch_handler_frame_index + 1;
}
DCHECK_NULL(output_);
output_ = new FrameDescription*[count];
for (size_t i = 0; i < count; ++i) {
output_[i] = nullptr;
}
output_count_ = static_cast<int>(count);
// Translate each output frame.
int frame_index = 0; // output_frame_index
size_t total_output_frame_size = 0;
for (size_t i = 0; i < count; ++i, ++frame_index) {
// Read the ast node id, function, and frame height for this output frame.
TranslatedFrame* translated_frame = &(translated_state_.frames()[i]);
bool handle_exception = deoptimizing_throw_ && i == count - 1;
switch (translated_frame->kind()) {
case TranslatedFrame::kInterpretedFunction:
DoComputeInterpretedFrame(translated_frame, frame_index,
handle_exception);
jsframe_count_++;
break;
case TranslatedFrame::kArgumentsAdaptor:
DoComputeArgumentsAdaptorFrame(translated_frame, frame_index);
break;
case TranslatedFrame::kConstructStub:
DoComputeConstructStubFrame(translated_frame, frame_index);
break;
case TranslatedFrame::kBuiltinContinuation:
DoComputeBuiltinContinuation(translated_frame, frame_index,
BuiltinContinuationMode::STUB);
break;
case TranslatedFrame::kJavaScriptBuiltinContinuation:
DoComputeBuiltinContinuation(translated_frame, frame_index,
BuiltinContinuationMode::JAVASCRIPT);
break;
case TranslatedFrame::kJavaScriptBuiltinContinuationWithCatch:
DoComputeBuiltinContinuation(
translated_frame, frame_index,
handle_exception
? BuiltinContinuationMode::JAVASCRIPT_HANDLE_EXCEPTION
: BuiltinContinuationMode::JAVASCRIPT_WITH_CATCH);
break;
case TranslatedFrame::kInvalid:
FATAL("invalid frame");
break;
}
total_output_frame_size += output_[frame_index]->GetFrameSize();
}
FrameDescription* topmost = output_[count - 1];
topmost->GetRegisterValues()->SetRegister(kRootRegister.code(),
isolate()->isolate_root());
// Print some helpful diagnostic information.
if (trace_scope_ != nullptr) {
double ms = timer.Elapsed().InMillisecondsF();
int index = output_count_ - 1; // Index of the topmost frame.
PrintF(trace_scope_->file(), "[deoptimizing (%s): end ",
MessageFor(deopt_kind_));
PrintFunctionName();
PrintF(trace_scope_->file(),
" @%d => node=%d, pc=" V8PRIxPTR_FMT ", caller sp=" V8PRIxPTR_FMT
", took %0.3f ms]\n",
bailout_id_, node_id.ToInt(), output_[index]->GetPc(),
caller_frame_top_, ms);
}
// The following invariant is fairly tricky to guarantee, since the size of
// an optimized frame and its deoptimized counterparts usually differs. We
// thus need to consider the case in which deoptimized frames are larger than
// the optimized frame in stack checks in optimized code. We do this by
// applying an offset to stack checks (see kArchStackPointerGreaterThan in the
// code generator).
// Note that we explicitly allow deopts to exceed the limit by a certain
// number of slack bytes.
CHECK_GT(
static_cast<uintptr_t>(caller_frame_top_) - total_output_frame_size,
stack_guard->real_jslimit() - kStackLimitSlackForDeoptimizationInBytes);
}
void Deoptimizer::DoComputeInterpretedFrame(TranslatedFrame* translated_frame,
int frame_index,
bool goto_catch_handler) {
SharedFunctionInfo shared = translated_frame->raw_shared_info();
TranslatedFrame::iterator value_iterator = translated_frame->begin();
const bool is_bottommost = (0 == frame_index);
const bool is_topmost = (output_count_ - 1 == frame_index);
const int real_bytecode_offset = translated_frame->node_id().ToInt();
const int bytecode_offset =
goto_catch_handler ? catch_handler_pc_offset_ : real_bytecode_offset;
const int parameters_count = InternalFormalParameterCountWithReceiver(shared);
const int locals_count = translated_frame->height();
InterpretedFrameInfo frame_info =
InterpretedFrameInfo::Precise(parameters_count, locals_count, is_topmost);
const uint32_t output_frame_size = frame_info.frame_size_in_bytes();
TranslatedFrame::iterator function_iterator = value_iterator++;
if (trace_scope_ != nullptr) {
PrintF(trace_scope_->file(), " translating interpreted frame ");
std::unique_ptr<char[]> name = shared.DebugName().ToCString();
PrintF(trace_scope_->file(), "%s", name.get());
PrintF(trace_scope_->file(),
" => bytecode_offset=%d, variable_frame_size=%d, frame_size=%d%s\n",
real_bytecode_offset, frame_info.frame_size_in_bytes_without_fixed(),
output_frame_size, goto_catch_handler ? " (throw)" : "");
}
// Allocate and store the output frame description.
FrameDescription* output_frame = new (output_frame_size)
FrameDescription(output_frame_size, parameters_count);
FrameWriter frame_writer(this, output_frame, trace_scope_);
CHECK(frame_index >= 0 && frame_index < output_count_);
CHECK_NULL(output_[frame_index]);
output_[frame_index] = output_frame;
// The top address of the frame is computed from the previous frame's top and
// this frame's size.
const intptr_t top_address =
is_bottommost ? caller_frame_top_ - output_frame_size
: output_[frame_index - 1]->GetTop() - output_frame_size;
output_frame->SetTop(top_address);
// Compute the incoming parameter translation.
ReadOnlyRoots roots(isolate());
if (ShouldPadArguments(parameters_count)) {
frame_writer.PushRawObject(roots.the_hole_value(), "padding\n");
}
for (int i = 0; i < parameters_count; ++i, ++value_iterator) {
frame_writer.PushTranslatedValue(value_iterator, "stack parameter");
}
DCHECK_EQ(output_frame->GetLastArgumentSlotOffset(),
frame_writer.top_offset());
if (trace_scope_ != nullptr) {
PrintF(trace_scope_->file(), " -------------------------\n");
}
// There are no translation commands for the caller's pc and fp, the
// context, the function and the bytecode offset. Synthesize
// their values and set them up
// explicitly.
//
// The caller's pc for the bottommost output frame is the same as in the
// input frame. For all subsequent output frames, it can be read from the
// previous one. This frame's pc can be computed from the non-optimized
// function code and AST id of the bailout.
const intptr_t caller_pc =
is_bottommost ? caller_pc_ : output_[frame_index - 1]->GetPc();
frame_writer.PushCallerPc(caller_pc);
// The caller's frame pointer for the bottommost output frame is the same
// as in the input frame. For all subsequent output frames, it can be
// read from the previous one. Also compute and set this frame's frame
// pointer.
const intptr_t caller_fp =
is_bottommost ? caller_fp_ : output_[frame_index - 1]->GetFp();
frame_writer.PushCallerFp(caller_fp);
const intptr_t fp_value = top_address + frame_writer.top_offset();
output_frame->SetFp(fp_value);
if (is_topmost) {
Register fp_reg = InterpretedFrame::fp_register();
output_frame->SetRegister(fp_reg.code(), fp_value);
}
if (FLAG_enable_embedded_constant_pool) {
// For the bottommost output frame the constant pool pointer can be gotten
// from the input frame. For subsequent output frames, it can be read from
// the previous frame.
const intptr_t caller_cp =
is_bottommost ? caller_constant_pool_
: output_[frame_index - 1]->GetConstantPool();
frame_writer.PushCallerConstantPool(caller_cp);
}
// For the bottommost output frame the context can be gotten from the input
// frame. For all subsequent output frames it can be gotten from the function
// so long as we don't inline functions that need local contexts.
// When deoptimizing into a catch block, we need to take the context
// from a register that was specified in the handler table.
TranslatedFrame::iterator context_pos = value_iterator++;
if (goto_catch_handler) {
// Skip to the translated value of the register specified
// in the handler table.
for (int i = 0; i < catch_handler_data_ + 1; ++i) {
context_pos++;
}
}
// Read the context from the translations.
Object context = context_pos->GetRawValue();
output_frame->SetContext(static_cast<intptr_t>(context.ptr()));
frame_writer.PushTranslatedValue(context_pos, "context");
// The function was mentioned explicitly in the BEGIN_FRAME.
frame_writer.PushTranslatedValue(function_iterator, "function");
// Set the bytecode array pointer.
Object bytecode_array = shared.HasBreakInfo()
? shared.GetDebugInfo().DebugBytecodeArray()
: shared.GetBytecodeArray();
frame_writer.PushRawObject(bytecode_array, "bytecode array\n");
// The bytecode offset was mentioned explicitly in the BEGIN_FRAME.
const int raw_bytecode_offset =
BytecodeArray::kHeaderSize - kHeapObjectTag + bytecode_offset;
Smi smi_bytecode_offset = Smi::FromInt(raw_bytecode_offset);
frame_writer.PushRawObject(smi_bytecode_offset, "bytecode offset\n");
if (trace_scope_ != nullptr) {
PrintF(trace_scope_->file(), " -------------------------\n");
}