blob: 9275d9729c09eb7d8f6237772f46352935ca8f4e [file] [log] [blame]
// 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 "src/base/memory.h"
#include "src/codegen/interface-descriptors.h"
#include "src/codegen/register-configuration.h"
#include "src/codegen/reloc-info.h"
#include "src/debug/debug.h"
#include "src/deoptimizer/deoptimized-frame-info.h"
#include "src/deoptimizer/materialized-object-store.h"
#include "src/deoptimizer/translated-state.h"
#include "src/execution/frames-inl.h"
#include "src/execution/isolate.h"
#include "src/execution/pointer-authentication.h"
#include "src/execution/v8threads.h"
#include "src/handles/handles-inl.h"
#include "src/heap/heap-inl.h"
#include "src/logging/counters.h"
#include "src/logging/log.h"
#include "src/logging/runtime-call-stats-scope.h"
#include "src/objects/deoptimization-data.h"
#include "src/objects/js-function-inl.h"
#include "src/objects/oddball.h"
#include "src/snapshot/embedded/embedded-data.h"
#include "src/utils/utils.h"
#if V8_ENABLE_WEBASSEMBLY
#include "src/wasm/baseline/liftoff-varstate.h"
#include "src/wasm/compilation-environment-inl.h"
#include "src/wasm/function-compiler.h"
#include "src/wasm/wasm-deopt-data.h"
#include "src/wasm/wasm-engine.h"
#include "src/wasm/wasm-linkage.h"
#endif // V8_ENABLE_WEBASSEMBLY
namespace v8 {
using base::Memory;
namespace internal {
namespace {
class DeoptimizableCodeIterator {
public:
explicit DeoptimizableCodeIterator(Isolate* isolate);
DeoptimizableCodeIterator(const DeoptimizableCodeIterator&) = delete;
DeoptimizableCodeIterator& operator=(const DeoptimizableCodeIterator&) =
delete;
Tagged<Code> Next();
private:
Isolate* const isolate_;
std::unique_ptr<SafepointScope> safepoint_scope_;
std::unique_ptr<ObjectIterator> object_iterator_;
enum { kIteratingCodeSpace, kIteratingCodeLOSpace, kDone } state_;
DISALLOW_GARBAGE_COLLECTION(no_gc)
};
DeoptimizableCodeIterator::DeoptimizableCodeIterator(Isolate* isolate)
: isolate_(isolate),
safepoint_scope_(std::make_unique<SafepointScope>(
isolate, isolate->is_shared_space_isolate()
? SafepointKind::kGlobal
: SafepointKind::kIsolate)),
object_iterator_(
isolate->heap()->code_space()->GetObjectIterator(isolate->heap())),
state_(kIteratingCodeSpace) {}
Tagged<Code> DeoptimizableCodeIterator::Next() {
while (true) {
Tagged<HeapObject> object = object_iterator_->Next();
if (object.is_null()) {
// No objects left in the current iterator, try to move to the next space
// based on the state.
switch (state_) {
case kIteratingCodeSpace: {
object_iterator_ =
isolate_->heap()->code_lo_space()->GetObjectIterator(
isolate_->heap());
state_ = kIteratingCodeLOSpace;
continue;
}
case kIteratingCodeLOSpace:
// No other spaces to iterate, so clean up and we're done. Keep the
// object iterator so that it keeps returning null on Next(), to avoid
// needing to branch on state_ before the while loop, but drop the
// safepoint scope since we no longer need to stop the heap from
// moving.
safepoint_scope_.reset();
state_ = kDone;
[[fallthrough]];
case kDone:
return Code();
}
}
Tagged<InstructionStream> istream = InstructionStream::cast(object);
Tagged<Code> code;
if (!istream->TryGetCode(&code, kAcquireLoad)) continue;
if (!CodeKindCanDeoptimize(code->kind())) continue;
return code;
}
}
} // namespace
// {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.
//
// Note: Not in an anonymous namespace due to the friend class declaration
// in Deoptimizer.
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(Tagged<Object> obj, const char* debug_hint) {
intptr_t value = obj.ptr();
PushValue(value);
if (trace_scope_ != nullptr) {
DebugPrintOutputObject(obj, top_offset_, debug_hint);
}
}
// There is no check against the allowed addresses for bottommost frames, as
// the caller's pc could be anything. The caller's pc pushed here should never
// be re-signed.
void PushBottommostCallerPc(intptr_t pc) {
top_offset_ -= kPCOnStackSize;
frame_->SetFrameSlot(top_offset_, pc);
DebugPrintOutputPc(pc, "bottommost caller's pc\n");
}
void PushApprovedCallerPc(intptr_t pc) {
top_offset_ -= kPCOnStackSize;
frame_->SetCallerPc(top_offset_, pc);
DebugPrintOutputPc(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 = "") {
Tagged<Object> obj = iterator->GetRawValue();
PushRawObject(obj, debug_hint);
if (trace_scope_ != nullptr) {
PrintF(trace_scope_->file(), " (input #%d)\n", iterator.input_index());
}
deoptimizer_->QueueValueForMaterialization(output_address(top_offset_), obj,
iterator);
}
void PushFeedbackVectorForMaterialization(
const TranslatedFrame::iterator& iterator) {
// Push a marker temporarily.
PushRawObject(ReadOnlyRoots(deoptimizer_->isolate()).arguments_marker(),
"feedback vector");
deoptimizer_->QueueFeedbackVectorForMaterialization(
output_address(top_offset_), iterator);
}
void PushStackJSArguments(TranslatedFrame::iterator& iterator,
int parameters_count) {
std::vector<TranslatedFrame::iterator> parameters;
parameters.reserve(parameters_count);
for (int i = 0; i < parameters_count; ++i, ++iterator) {
parameters.push_back(iterator);
}
for (auto& parameter : base::Reversed(parameters)) {
PushTranslatedValue(parameter, "stack parameter");
}
}
unsigned top_offset() const { return top_offset_; }
FrameDescription* frame() { return frame_; }
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 DebugPrintOutputPc(intptr_t value, const char* debug_hint = "") {
#ifdef V8_ENABLE_CONTROL_FLOW_INTEGRITY
if (trace_scope_ != nullptr) {
PrintF(trace_scope_->file(),
" " V8PRIxPTR_FMT ": [top + %3d] <- " V8PRIxPTR_FMT
" (signed) " V8PRIxPTR_FMT " (unsigned) ; %s",
output_address(top_offset_), top_offset_, value,
PointerAuthentication::StripPAC(value), debug_hint);
}
#else
DebugPrintOutputValue(value, debug_hint);
#endif
}
void DebugPrintOutputObject(Tagged<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 (IsSmi(obj)) {
PrintF(trace_scope_->file(), V8PRIxPTR_FMT " <Smi %d>", obj.ptr(),
Smi::cast(obj).value());
} else {
ShortPrint(obj, trace_scope_->file());
}
PrintF(trace_scope_->file(), " ; %s", debug_hint);
}
}
Deoptimizer* deoptimizer_;
FrameDescription* frame_;
CodeTracer::Scope* const trace_scope_;
unsigned top_offset_;
};
// 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,
Address from, int fp_to_sp_delta,
Isolate* isolate) {
// This is zero for wasm.
Tagged<JSFunction> function =
raw_function != 0 ? JSFunction::cast(Tagged<Object>(raw_function))
: Tagged<JSFunction>();
Deoptimizer* deoptimizer =
new Deoptimizer(isolate, function, kind, from, fp_to_sp_delta);
isolate->set_current_deoptimizer(deoptimizer);
return deoptimizer;
}
Deoptimizer* Deoptimizer::Grab(Isolate* isolate) {
Deoptimizer* result = isolate->GetAndClearCurrentDeoptimizer();
result->DeleteFrameDescriptions();
return result;
}
void Deoptimizer::DeleteForWasm(Isolate* isolate) {
// The deoptimizer disallows garbage collections.
DCHECK(!AllowGarbageCollection::IsAllowed());
Deoptimizer* deoptimizer = Deoptimizer::Grab(isolate);
delete deoptimizer;
// Now garbage collections are allowed again.
DCHECK(AllowGarbageCollection::IsAllowed());
}
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::kUnoptimizedFunction ||
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::kUnoptimizedFunction);
DeoptimizedFrameInfo* info =
new DeoptimizedFrameInfo(&translated_values, frame_it, isolate);
return info;
}
namespace {
class ActivationsFinder : public ThreadVisitor {
public:
ActivationsFinder(Tagged<GcSafeCode> topmost_optimized_code,
bool safe_to_deopt_topmost_optimized_code) {
#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()->is_optimized()) {
Tagged<GcSafeCode> code = it.frame()->GcSafeLookupCode();
if (CodeKindCanDeoptimize(code->kind()) &&
code->marked_for_deoptimization()) {
// Obtain the trampoline to the deoptimizer call.
int trampoline_pc;
if (code->is_maglevved()) {
MaglevSafepointEntry safepoint = MaglevSafepointTable::FindEntry(
isolate, code, it.frame()->pc());
trampoline_pc = safepoint.trampoline_pc();
} else {
SafepointEntry safepoint = SafepointTable::FindEntry(
isolate, code, it.frame()->maybe_unauthenticated_pc());
trampoline_pc = safepoint.trampoline_pc();
}
// TODO(saelo): currently we have to use full pointer comparison as
// builtin Code is still inside the sandbox while runtime-generated
// Code is in trusted space.
static_assert(!kAllCodeObjectsLiveInTrustedSpace);
DCHECK_IMPLIES(code.SafeEquals(topmost_), safe_to_deopt_);
static_assert(SafepointEntry::kNoTrampolinePC == -1);
CHECK_GE(trampoline_pc, 0);
// Replace the current pc on the stack with the trampoline.
// TODO(v8:10026): avoid replacing a signed pointer.
if (!it.frame()->InFastCCall()) {
Address* pc_addr = it.frame()->pc_address();
Address new_pc = code->instruction_start() + trampoline_pc;
PointerAuthentication::ReplacePC(pc_addr, new_pc,
kSystemPointerSize);
}
}
}
}
}
private:
#ifdef DEBUG
Tagged<GcSafeCode> topmost_;
bool safe_to_deopt_;
#endif
};
} // namespace
// Replace pc on the stack for codes marked for deoptimization.
// static
void Deoptimizer::DeoptimizeMarkedCode(Isolate* isolate) {
DisallowGarbageCollection no_gc;
Tagged<GcSafeCode> 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()) {
if (it.frame()->is_optimized()) {
Tagged<GcSafeCode> code = it.frame()->GcSafeLookupCode();
Tagged<JSFunction> function =
static_cast<OptimizedFrame*>(it.frame())->function();
TraceFoundActivation(isolate, function);
bool safe_if_deopt_triggered;
if (code->is_maglevved()) {
MaglevSafepointEntry safepoint =
MaglevSafepointTable::FindEntry(isolate, code, it.frame()->pc());
safe_if_deopt_triggered = safepoint.has_deoptimization_index();
} else {
SafepointEntry safepoint = SafepointTable::FindEntry(
isolate, code, it.frame()->maybe_unauthenticated_pc());
safe_if_deopt_triggered = safepoint.has_deoptimization_index();
}
// Deopt is checked when we are patching addresses on stack.
bool is_builtin_code = code->kind() == CodeKind::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
ActivationsFinder visitor(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);
}
void Deoptimizer::DeoptimizeAll(Isolate* isolate) {
RCS_SCOPE(isolate, RuntimeCallCounterId::kDeoptimizeCode);
TimerEventScope<TimerEventDeoptimizeCode> timer(isolate);
TRACE_EVENT0("v8", "V8.DeoptimizeCode");
TraceDeoptAll(isolate);
isolate->AbortConcurrentOptimization(BlockingBehavior::kBlock);
// Mark all code, then deoptimize.
{
DeoptimizableCodeIterator it(isolate);
for (Tagged<Code> code = it.Next(); !code.is_null(); code = it.Next()) {
code->set_marked_for_deoptimization(true);
}
}
DeoptimizeMarkedCode(isolate);
}
// static
void Deoptimizer::DeoptimizeFunction(Tagged<JSFunction> function,
Tagged<Code> code) {
Isolate* isolate = function->GetIsolate();
RCS_SCOPE(isolate, RuntimeCallCounterId::kDeoptimizeCode);
TimerEventScope<TimerEventDeoptimizeCode> timer(isolate);
TRACE_EVENT0("v8", "V8.DeoptimizeCode");
if (v8_flags.profile_guided_optimization) {
function->shared()->set_cached_tiering_decision(
CachedTieringDecision::kNormal);
}
function->ResetIfCodeFlushed(isolate);
if (code.is_null()) code = function->code(isolate);
if (CodeKindCanDeoptimize(code->kind())) {
// 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(
isolate, function->shared(), "unlinking code marked for deopt");
DeoptimizeMarkedCode(isolate);
}
}
// static
void Deoptimizer::DeoptimizeAllOptimizedCodeWithFunction(
Isolate* isolate, Handle<SharedFunctionInfo> function) {
RCS_SCOPE(isolate, RuntimeCallCounterId::kDeoptimizeCode);
TimerEventScope<TimerEventDeoptimizeCode> timer(isolate);
TRACE_EVENT0("v8", "V8.DeoptimizeAllOptimizedCodeWithFunction");
// Make sure no new code is compiled with the function.
isolate->AbortConcurrentOptimization(BlockingBehavior::kBlock);
// Mark all code that inlines this function, then deoptimize.
bool any_marked = false;
{
DeoptimizableCodeIterator it(isolate);
for (Tagged<Code> code = it.Next(); !code.is_null(); code = it.Next()) {
if (code->Inlines(*function)) {
code->set_marked_for_deoptimization(true);
any_marked = true;
}
}
}
if (any_marked) {
DeoptimizeMarkedCode(isolate);
}
}
void Deoptimizer::ComputeOutputFrames(Deoptimizer* deoptimizer) {
deoptimizer->DoComputeOutputFrames();
}
const char* Deoptimizer::MessageFor(DeoptimizeKind kind) {
switch (kind) {
case DeoptimizeKind::kEager:
return "deopt-eager";
case DeoptimizeKind::kLazy:
return "deopt-lazy";
}
}
Deoptimizer::Deoptimizer(Isolate* isolate, Tagged<JSFunction> function,
DeoptimizeKind kind, Address from, int fp_to_sp_delta)
: isolate_(isolate),
function_(function),
deopt_exit_index_(kFixedExitSizeMarker),
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),
restart_frame_index_(-1),
input_(nullptr),
output_count_(0),
output_(nullptr),
caller_frame_top_(0),
caller_fp_(0),
caller_pc_(0),
caller_constant_pool_(0),
actual_argument_count_(0),
stack_fp_(0),
trace_scope_(v8_flags.trace_deopt || v8_flags.log_deopt
? new CodeTracer::Scope(isolate->GetCodeTracer())
: nullptr) {
if (isolate->deoptimizer_lazy_throw()) {
CHECK_EQ(kind, DeoptimizeKind::kLazy);
isolate->set_deoptimizer_lazy_throw(false);
deoptimizing_throw_ = true;
}
if (isolate->debug()->IsRestartFrameScheduled()) {
CHECK(deoptimizing_throw_);
restart_frame_index_ = isolate->debug()->restart_inline_frame_index();
CHECK_GE(restart_frame_index_, 0);
isolate->debug()->clear_restart_frame();
}
DCHECK_NE(from, kNullAddress);
#ifdef DEBUG
DCHECK(AllowGarbageCollection::IsAllowed());
disallow_garbage_collection_ = new DisallowGarbageCollection();
#endif // DEBUG
#if V8_ENABLE_WEBASSEMBLY
if (v8_flags.wasm_deopt && function.is_null()) {
wasm::WasmCode* code =
wasm::GetWasmCodeManager()->LookupCode(isolate, from);
compiled_optimized_wasm_code_ = code;
DCHECK_NOT_NULL(code);
DCHECK_EQ(code->kind(), wasm::WasmCode::kWasmFunction);
wasm::WasmDeoptView deopt_view(code->deopt_data());
const wasm::WasmDeoptData& deopt_data = deopt_view.GetDeoptData();
DCHECK_NE(deopt_data.translation_array_size, 0);
DCHECK_GE(from, deopt_data.deopt_exit_start_offset);
Address deopt_exit_offset = from - code->instruction_start();
// All eager deopt exits are calls "at the end" of the code to the builtin
// generated by Generate_DeoptimizationEntry_Eager. These calls have a fixed
// size kEagerDeoptExitsSize and the deopt data contains the offset of the
// first such call to the beginning of the code, so we can map any PC of
// such call to a unique index for this deopt point.
deopt_exit_index_ =
static_cast<uint32_t>(deopt_exit_offset -
deopt_data.deopt_exit_start_offset -
kEagerDeoptExitSize) /
kEagerDeoptExitSize;
// Note: The parameter stack slots are not really part of the frame.
// However, the deoptimizer needs access to the incoming parameter values
// and therefore they need to be included in the FrameDescription. Between
// the parameters and the actual frame there are 2 pointers (the caller's pc
// and saved stack pointer) that therefore also need to be included. Both
// pointers as well as the incoming parameter stack slots are going to be
// copied into the outgoing FrameDescription which will "push" them back
// onto the stack. (This is consistent with how JS handles this.)
const int parameter_slots = code->first_tagged_parameter_slot() +
code->num_tagged_parameter_slots();
unsigned input_frame_size = fp_to_sp_delta +
parameter_slots * kSystemPointerSize +
CommonFrameConstants::kFixedFrameSizeAboveFp;
input_ =
FrameDescription::Create(input_frame_size, parameter_slots, isolate_);
return;
}
#endif
compiled_code_ = isolate_->heap()->FindCodeForInnerPointer(from);
DCHECK(!compiled_code_.is_null());
DCHECK(IsCode(compiled_code_));
DCHECK(IsJSFunction(function));
CHECK(CodeKindCanDeoptimize(compiled_code_->kind()));
{
HandleScope scope(isolate_);
PROFILE(isolate_, CodeDeoptEvent(handle(compiled_code_, isolate_), kind,
from_, fp_to_sp_delta_));
}
unsigned size = ComputeInputFrameSize();
const int parameter_count =
function->shared()->internal_formal_parameter_count_with_receiver();
// The parameter count from the (in-sandbox) SFI must match the actual
// parameter count of the Code that we are deoptimizing. For now, we use a
// SBXCHECK here to ensure that these values are always equal. In the future,
// we should change the deoptimizer to use the (trusted) parameter count from
// the Code object everywhere, at which point we could drop this again.
SBXCHECK_EQ(parameter_count, compiled_code_->parameter_count());
input_ = FrameDescription::Create(size, parameter_count, isolate_);
DCHECK_EQ(deopt_exit_index_, kFixedExitSizeMarker);
// Calculate the deopt exit index from return address.
DCHECK_GT(kEagerDeoptExitSize, 0);
DCHECK_GT(kLazyDeoptExitSize, 0);
Tagged<DeoptimizationData> deopt_data =
DeoptimizationData::cast(compiled_code_->deoptimization_data());
Address deopt_start = compiled_code_->instruction_start() +
deopt_data->DeoptExitStart().value();
int eager_deopt_count = deopt_data->EagerDeoptCount().value();
Address lazy_deopt_start =
deopt_start + eager_deopt_count * kEagerDeoptExitSize;
// The deoptimization exits are sorted so that lazy deopt exits appear after
// eager deopts.
static_assert(static_cast<int>(DeoptimizeKind::kLazy) ==
static_cast<int>(kLastDeoptimizeKind),
"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 <=, similarly for the last non-lazy deopt and
// the first deopt with resume entry.
if (from_ <= lazy_deopt_start) {
DCHECK_EQ(kind, DeoptimizeKind::kEager);
int offset = static_cast<int>(from_ - kEagerDeoptExitSize - deopt_start);
DCHECK_EQ(0, offset % kEagerDeoptExitSize);
deopt_exit_index_ = offset / kEagerDeoptExitSize;
} else {
DCHECK_EQ(kind, DeoptimizeKind::kLazy);
int offset =
static_cast<int>(from_ - kLazyDeoptExitSize - lazy_deopt_start);
DCHECK_EQ(0, offset % kLazyDeoptExitSize);
deopt_exit_index_ = eager_deopt_count + (offset / kLazyDeoptExitSize);
}
}
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_garbage_collection_);
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(!AllowGarbageCollection::IsAllowed());
DCHECK_NOT_NULL(disallow_garbage_collection_);
delete disallow_garbage_collection_;
disallow_garbage_collection_ = nullptr;
#endif // DEBUG
}
Builtin Deoptimizer::GetDeoptimizationEntry(DeoptimizeKind kind) {
switch (kind) {
case DeoptimizeKind::kEager:
return Builtin::kDeoptimizationEntry_Eager;
case DeoptimizeKind::kLazy:
return Builtin::kDeoptimizationEntry_Lazy;
}
}
namespace {
int LookupCatchHandler(Isolate* isolate, TranslatedFrame* translated_frame,
int* data_out) {
switch (translated_frame->kind()) {
case TranslatedFrame::kUnoptimizedFunction: {
int bytecode_offset = translated_frame->bytecode_offset().ToInt();
HandlerTable table(
translated_frame->raw_shared_info()->GetBytecodeArray(isolate));
int handler_index = table.LookupHandlerIndexForRange(bytecode_offset);
if (handler_index == HandlerTable::kNoHandlerFound) return handler_index;
*data_out = table.GetRangeData(handler_index);
table.MarkHandlerUsed(handler_index);
return table.GetRangeHandler(handler_index);
}
case TranslatedFrame::kJavaScriptBuiltinContinuationWithCatch: {
return 0;
}
default:
break;
}
return -1;
}
} // namespace
void Deoptimizer::TraceDeoptBegin(int optimization_id,
BytecodeOffset bytecode_offset) {
DCHECK(tracing_enabled());
FILE* file = trace_scope()->file();
Deoptimizer::DeoptInfo info = Deoptimizer::GetDeoptInfo();
PrintF(file, "[bailout (kind: %s, reason: %s): begin. deoptimizing ",
MessageFor(deopt_kind_), DeoptimizeReasonToString(info.deopt_reason));
if (IsJSFunction(function_)) {
ShortPrint(function_, file);
PrintF(file, ", ");
}
ShortPrint(compiled_code_, file);
PrintF(file,
", opt id %d, "
#ifdef DEBUG
"node id %d, "
#endif // DEBUG
"bytecode offset %d, deopt exit %d, FP to SP "
"delta %d, "
"caller SP " V8PRIxPTR_FMT ", pc " V8PRIxPTR_FMT "]\n",
optimization_id,
#ifdef DEBUG
info.node_id,
#endif // DEBUG
bytecode_offset.ToInt(), deopt_exit_index_, fp_to_sp_delta_,
caller_frame_top_, PointerAuthentication::StripPAC(from_));
if (verbose_tracing_enabled() && deopt_kind_ != DeoptimizeKind::kLazy) {
PrintF(file, " ;;; deoptimize at ");
OFStream outstr(file);
info.position.Print(outstr, compiled_code_);
PrintF(file, "\n");
}
}
void Deoptimizer::TraceDeoptEnd(double deopt_duration) {
DCHECK(verbose_tracing_enabled());
PrintF(trace_scope()->file(), "[bailout end. took %0.3f ms]\n",
deopt_duration);
}
// static
void Deoptimizer::TraceMarkForDeoptimization(Isolate* isolate,
Tagged<Code> code,
const char* reason) {
DCHECK(code->uses_deoptimization_data());
if (!v8_flags.trace_deopt && !v8_flags.log_deopt) return;
DisallowGarbageCollection no_gc;
Tagged<DeoptimizationData> deopt_data =
DeoptimizationData::cast(code->deoptimization_data());
CodeTracer::Scope scope(isolate->GetCodeTracer());
if (v8_flags.trace_deopt) {
PrintF(scope.file(), "[marking dependent code ");
ShortPrint(code, scope.file());
PrintF(scope.file(), " (");
ShortPrint(deopt_data->SharedFunctionInfo(), scope.file());
PrintF(") (opt id %d) for deoptimization, reason: %s]\n",
deopt_data->OptimizationId().value(), reason);
}
if (!v8_flags.log_deopt) return;
no_gc.Release();
{
HandleScope handle_scope(isolate);
PROFILE(
isolate,
CodeDependencyChangeEvent(
handle(code, isolate),
handle(SharedFunctionInfo::cast(deopt_data->SharedFunctionInfo()),
isolate),
reason));
}
}
// static
void Deoptimizer::TraceEvictFromOptimizedCodeCache(
Isolate* isolate, Tagged<SharedFunctionInfo> sfi, const char* reason) {
if (!v8_flags.trace_deopt_verbose) return;
DisallowGarbageCollection no_gc;
CodeTracer::Scope scope(isolate->GetCodeTracer());
PrintF(scope.file(),
"[evicting optimized code marked for deoptimization (%s) for ",
reason);
ShortPrint(sfi, scope.file());
PrintF(scope.file(), "]\n");
}
#ifdef DEBUG
// static
void Deoptimizer::TraceFoundActivation(Isolate* isolate,
Tagged<JSFunction> function) {
if (!v8_flags.trace_deopt_verbose) return;
CodeTracer::Scope scope(isolate->GetCodeTracer());
PrintF(scope.file(), "[deoptimizer found activation of function: ");
function->PrintName(scope.file());
PrintF(scope.file(), " / %" V8PRIxPTR "]\n", function.ptr());
}
#endif // DEBUG
// static
void Deoptimizer::TraceDeoptAll(Isolate* isolate) {
if (!v8_flags.trace_deopt_verbose) return;
CodeTracer::Scope scope(isolate->GetCodeTracer());
PrintF(scope.file(), "[deoptimize all code in all contexts]\n");
}
FrameDescription* Deoptimizer::DoComputeWasmLiftoffFrame(
TranslatedFrame& frame, wasm::NativeModule* native_module,
int frame_index) {
#if !V8_ENABLE_WEBASSEMBLY
UNREACHABLE();
#else
const bool is_bottommost = frame_index == 0;
const bool is_topmost = output_count_ - 1 == frame_index;
// Recompile the liftoff (unoptimized) wasm code for the input frame.
// TODO(mliedtke): This recompiles every single function even if it never got
// optimized and exists as a liftoff variant in the WasmCodeManager as we also
// need to compute the deopt information. Can we avoid some of the extra work
// here?
wasm::WasmCompilationUnit unit(frame.wasm_function_index(),
wasm::ExecutionTier::kLiftoff,
wasm::ForDebugging::kNotForDebugging);
wasm::WasmFeatures detected;
wasm::CompilationEnv env = wasm::CompilationEnv::ForModule(native_module);
env.deopt_info_bytecode_offset = frame.bytecode_offset().ToInt();
std::shared_ptr<wasm::WireBytesStorage> wire_bytes =
native_module->compilation_state()->GetWireBytesStorage();
wasm::WasmCompilationResult result =
unit.ExecuteCompilation(&env, &*wire_bytes, nullptr, &detected);
// Replace the optimized code with the unoptimized code in the
// WasmCodeManager as a deopt was reached.
std::unique_ptr<wasm::WasmCode> compiled_code =
native_module->AddCompiledCode(result);
wasm::WasmCodeRefScope code_ref_scope;
// TODO(mliedtke): This might unoptimize functions because they were inlined
// into a function that now needs to deopt them while the optimized function
// might have taken different inlining decisions.
// TODO(mliedtke): The code cache should also be invalidated.
wasm::WasmCode* wasm_code =
native_module->PublishCode(std::move(compiled_code));
DCHECK(result.liftoff_frame_descriptions);
const wasm::LiftoffFrameDescription& liftoff_description =
result.liftoff_frame_descriptions->description;
if (verbose_tracing_enabled()) {
std::ostringstream outstream;
outstream << " Liftoff stack & register state for function index "
<< frame.wasm_function_index() << '\n';
size_t index = 0;
for (const wasm::LiftoffVarState& state : liftoff_description.var_state) {
outstream << " " << index++ << ": " << state << '\n';
}
FILE* file = trace_scope()->file();
PrintF(file, "%s", outstream.str().c_str());
}
const uint32_t parameter_stack_slots =
wasm_code->first_tagged_parameter_slot() +
wasm_code->num_tagged_parameter_slots();
// Allocate and populate the FrameDescription describing the output frame.
const uint32_t output_frame_size =
result.liftoff_frame_descriptions->total_frame_size;
const uint32_t total_output_frame_size =
output_frame_size + parameter_stack_slots * kSystemPointerSize +
CommonFrameConstants::kFixedFrameSizeAboveFp;
FrameDescription* output_frame = FrameDescription::Create(
total_output_frame_size, parameter_stack_slots, isolate());
// Copy the parameter stack slots.
static_assert(CommonFrameConstants::kFixedFrameSizeAboveFp ==
2 * kSystemPointerSize);
uint32_t input_offset = input_->GetFrameSize();
uint32_t output_offset = total_output_frame_size;
if (is_topmost) {
for (uint32_t i = 1; i <= parameter_stack_slots; ++i) {
input_offset -= kSystemPointerSize;
intptr_t value = input_->GetFrameSlot(input_offset);
output_offset -= kSystemPointerSize;
output_frame->SetFrameSlot(output_offset, value);
}
} else {
// Zero out the incoming parameter slots. This will make sure that tagged
// values are safely ignored by the gc.
// Note that zero is clearly not the correct value. Still, liftoff copies
// all parameters into "its own" stack slots at the beginning and always
// uses these slots to restore parameters from the stack.
for (uint32_t i = 0; i < parameter_stack_slots; ++i) {
output_offset -= kSystemPointerSize;
output_frame->SetFrameSlot(output_offset, 0);
}
}
// Store the caller PC.
output_offset -= kSystemPointerSize;
output_frame->SetFrameSlot(
output_offset,
is_bottommost ? caller_pc_ : output_[frame_index - 1]->GetPc());
// Store the caller frame pointer.
output_offset -= kSystemPointerSize;
output_frame->SetFrameSlot(
output_offset,
is_bottommost ? caller_fp_ : output_[frame_index - 1]->GetFp());
DCHECK_EQ(output_frame_size, output_offset);
int base_offset = output_frame_size;
// TODO(mliedtke): Move this outside the loop?
// Read the trusted instance data from the input frame.
// TODO(mliedtke): Due to reading it from a fixed frame location, can we
// remove the trusted instance from the deopt data?
Tagged<WasmTrustedInstanceData> wasm_trusted_instance =
Tagged<WasmTrustedInstanceData>::cast(
(Tagged<Object>(input_->GetFrameSlot(
input_->GetFrameSize() -
(2 + input_->parameter_count()) * kSystemPointerSize -
WasmLiftoffFrameConstants::kInstanceDataOffset))));
// Set trusted instance data on output frame.
output_frame->SetFrameSlot(
base_offset - WasmLiftoffFrameConstants::kInstanceDataOffset,
wasm_trusted_instance.ptr());
if (liftoff_description.trusted_instance != no_reg) {
DCHECK_EQ(liftoff_description.trusted_instance, kWasmInstanceRegister);
output_frame->SetRegister(liftoff_description.trusted_instance.code(),
wasm_trusted_instance.ptr());
}
DCHECK_GE(translated_state_.frames().size(), 1);
auto liftoff_iter = liftoff_description.var_state.begin();
DCHECK_EQ(liftoff_description.var_state.size(), frame.GetValueCount());
for (const TranslatedValue& value : frame) {
switch (liftoff_iter->loc()) {
case wasm::LiftoffVarState::kIntConst:
break; // Nothing to be done for constants in liftoff frame.
case wasm::LiftoffVarState::kRegister:
if (liftoff_iter->is_gp_reg()) {
output_frame->SetRegister(liftoff_iter->reg().gp().code(),
value.int64_value_);
} else if (liftoff_iter->is_fp_reg()) {
// TODO(mliedtke): These cases don't cover the cases where a double
// might be a word64 in Turboshaft due to optimizations etc.
Simd128 simd_value;
switch (value.kind()) {
case TranslatedValue::Kind::kDouble: {
Float64 double_value = value.double_value();
std::memcpy(&simd_value, &double_value, sizeof(double_value));
break;
}
case TranslatedValue::Kind::kFloat: {
Float32 float_value = value.float_value();
std::memcpy(&simd_value, &float_value, sizeof(float_value));
break;
}
case TranslatedValue::Kind::kSimd128:
simd_value = value.simd_value();
break;
default:
UNIMPLEMENTED();
}
output_frame->SetSimd128Register(liftoff_iter->reg().fp().code(),
simd_value);
} else {
// Register pairs, floating point registers and potentially others.
UNIMPLEMENTED();
}
break;
case wasm::LiftoffVarState::kStack:
switch (liftoff_iter->kind()) {
case wasm::ValueKind::kI32:
DCHECK(value.kind() == TranslatedValue::Kind::kInt32 ||
value.kind() == TranslatedValue::Kind::kUint32);
output_frame->SetLiftoffFrameSlot32(
base_offset - liftoff_iter->offset(), value.int32_value_);
break;
case wasm::ValueKind::kF32:
DCHECK_EQ(value.kind(), TranslatedValue::Kind::kFloat);
output_frame->SetLiftoffFrameSlot32(
base_offset - liftoff_iter->offset(),
value.float_value().get_bits());
break;
case wasm::ValueKind::kI64:
DCHECK(value.kind() == TranslatedValue::Kind::kInt64 ||
value.kind() == TranslatedValue::Kind::kUint64);
output_frame->SetLiftoffFrameSlot64(
base_offset - liftoff_iter->offset(), value.int64_value_);
break;
case wasm::ValueKind::kS128: {
int64x2 values = value.simd128_value_.to_i64x2();
const int offset = base_offset - liftoff_iter->offset();
output_frame->SetLiftoffFrameSlot64(offset, values.val[0]);
output_frame->SetLiftoffFrameSlot64(offset + sizeof(int64_t),
values.val[1]);
break;
}
case wasm::ValueKind::kF64:
DCHECK_EQ(value.kind(), TranslatedValue::Kind::kDouble);
output_frame->SetLiftoffFrameSlot64(
base_offset - liftoff_iter->offset(),
value.double_value().get_bits());
break;
case wasm::ValueKind::kRef:
case wasm::ValueKind::kRefNull:
DCHECK_EQ(value.kind(), TranslatedValue::Kind::kTagged);
output_frame->SetLiftoffFrameSlot64(
base_offset - liftoff_iter->offset(), value.raw_literal_.ptr());
break;
default:
UNIMPLEMENTED();
}
break;
}
++liftoff_iter;
}
// Store frame kind.
uint32_t frame_type_offset =
base_offset + WasmLiftoffFrameConstants::kFrameTypeOffset;
output_frame->SetFrameSlot(frame_type_offset,
StackFrame::TypeToMarker(StackFrame::WASM));
// Store feedback vector in stack slot.
Tagged<FixedArray> module_feedback =
wasm_trusted_instance->feedback_vectors();
uint32_t feedback_offset =
base_offset - WasmLiftoffFrameConstants::kFeedbackVectorOffset;
// There isn't feedback for imported functions, so feedback index 0 belongs to
// the first non-imported function etc.
uint32_t fct_feedback_index = frame.wasm_function_index() -
native_module->module()->num_imported_functions;
CHECK_LT(fct_feedback_index, module_feedback->length());
output_frame->SetFrameSlot(feedback_offset,
module_feedback->get(fct_feedback_index).ptr());
output_frame->SetPc(wasm_code->instruction_start() +
liftoff_description.pc_offset);
// Instead of a builtin continuation for wasm the deopt builtin will
// call a c function to destroy the Deoptimizer object and then directly
// return to the liftoff code.
output_frame->SetContinuation(0);
Address top = is_bottommost ? caller_frame_top_ - total_output_frame_size
: output_[frame_index - 1]->GetTop() -
total_output_frame_size;
output_frame->SetTop(top);
const intptr_t fp_value = top + output_frame_size;
output_frame->SetFp(fp_value);
Register fp_reg = JavaScriptFrame::fp_register();
output_frame->SetRegister(fp_reg.code(), fp_value);
output_frame->SetRegister(kRootRegister.code(), isolate()->isolate_root());
#ifdef V8_COMPRESS_POINTERS
output_frame->SetRegister(kPtrComprCageBaseRegister.code(),
isolate()->cage_base());
#endif
return output_frame;
#endif // !V8_ENABLE_WEBASSEMBLY
}
// Build up the output frames for a wasm deopt. This creates the
// FrameDescription objects representing the output frames to be "materialized"
// on the stack.
void Deoptimizer::DoComputeOutputFramesWasmImpl() {
#if !V8_ENABLE_WEBASSEMBLY
UNREACHABLE();
#else
CHECK(v8_flags.wasm_deopt);
// TODO(mliedtke): Remove useless extra scope.
{
base::ElapsedTimer timer;
// Lookup the deopt info for the input frame.
wasm::WasmCode* code = compiled_optimized_wasm_code_;
DCHECK_NOT_NULL(code);
DCHECK_EQ(code->kind(), wasm::WasmCode::kWasmFunction);
wasm::WasmDeoptView deopt_view(code->deopt_data());
wasm::WasmDeoptEntry deopt_entry =
deopt_view.GetDeoptEntry(deopt_exit_index_);
if (tracing_enabled()) {
timer.Start();
FILE* file = trace_scope()->file();
PrintF(file,
"[bailout (kind: %s, reason: %s, type: Wasm): begin. deoptimizing "
"%s, bytecode offset %d, deopt exit %d, FP to SP delta %d, "
"pc " V8PRIxPTR_FMT "]\n",
MessageFor(deopt_kind_),
DeoptimizeReasonToString(DeoptimizeReason::kWrongCallTarget),
code->DebugName().c_str(), deopt_entry.bytecode_offset.ToInt(),
deopt_entry.translation_index, fp_to_sp_delta_,
PointerAuthentication::StripPAC(from_));
}
base::Vector<const uint8_t> off_heap_translations =
deopt_view.GetTranslationsArray();
DeoptTranslationIterator state_iterator(off_heap_translations,
deopt_entry.translation_index);
wasm::NativeModule* native_module = code->native_module();
int parameter_count = static_cast<int>(native_module->module()
->functions[code->index()]
.sig->parameter_count());
DeoptimizationLiteralProvider literals(
deopt_view.BuildDeoptimizationLiteralArray());
Register fp_reg = JavaScriptFrame::fp_register();
stack_fp_ = input_->GetRegister(fp_reg.code());
Address fp_address = input_->GetFramePointerAddress();
caller_fp_ = Memory<intptr_t>(fp_address);
caller_pc_ =
Memory<intptr_t>(fp_address + CommonFrameConstants::kCallerPCOffset);
caller_frame_top_ = stack_fp_ +
CommonFrameConstants::kFixedFrameSizeAboveFp +
input_->parameter_count() * kSystemPointerSize;
FILE* trace_file =
verbose_tracing_enabled() ? trace_scope()->file() : nullptr;
translated_state_.Init(isolate_, input_->GetFramePointerAddress(),
stack_fp_, &state_iterator, literals,
input_->GetRegisterValues(), trace_file,
parameter_count, parameter_count);
const size_t output_frames = translated_state_.frames().size();
output_count_ = static_cast<int>(output_frames);
output_ = new FrameDescription* [output_frames] {};
for (int i = 0; i < output_count_; ++i) {
TranslatedFrame& frame = translated_state_.frames()[i];
output_[i] = DoComputeWasmLiftoffFrame(frame, native_module, i);
}
{
// Delete the cached feedback result produced by the
// TransitiveFeedbackProcessor from the module for all inlined functions.
// This is required to prevent deopt loops as new feedback is ignored
// otherwise.
wasm::TypeFeedbackStorage& feedback =
native_module->module()->type_feedback;
base::SharedMutexGuard<base::kShared> mutex_guard(&feedback.mutex);
for (const TranslatedFrame& frame : translated_state_) {
int index = frame.wasm_function_index();
auto iter = feedback.feedback_for_function.find(index);
if (iter != feedback.feedback_for_function.end()) {
iter->second.feedback_vector.clear();
}
}
}
if (verbose_tracing_enabled()) {
TraceDeoptEnd(timer.Elapsed().InMillisecondsF());
}
}
#endif
}
// 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 the DeoptimizationEntry builtin, so the
// stack is not iterable by the StackFrameIteratorForProfiler.
#if V8_TARGET_ARCH_STORES_RETURN_ADDRESS_ON_STACK
DCHECK_EQ(0, isolate()->isolate_data()->stack_is_iterable());
#endif
base::ElapsedTimer timer;
#if V8_ENABLE_WEBASSEMBLY
if (v8_flags.wasm_deopt && function_.is_null()) {
return DoComputeOutputFramesWasmImpl();
}
#endif
// Determine basic deoptimization information. The optimized frame is
// described by the input data.
Tagged<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);
actual_argument_count_ = static_cast<int>(
Memory<intptr_t>(fp_address + StandardFrameConstants::kArgCOffset));
if (V8_EMBEDDED_CONSTANT_POOL_BOOL) {
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());
BytecodeOffset bytecode_offset =
input_data->GetBytecodeOffsetOrBuiltinContinuationId(deopt_exit_index_);
auto translations = input_data->FrameTranslation();
unsigned translation_index =
input_data->TranslationIndex(deopt_exit_index_).value();
if (tracing_enabled()) {
timer.Start();
TraceDeoptBegin(input_data->OptimizationId().value(), bytecode_offset);
}
FILE* trace_file =
verbose_tracing_enabled() ? trace_scope()->file() : nullptr;
DeoptimizationFrameTranslation::Iterator state_iterator(translations,
translation_index);
DeoptimizationLiteralProvider literals(input_data->LiteralArray());
translated_state_.Init(
isolate_, input_->GetFramePointerAddress(), stack_fp_, &state_iterator,
literals, input_->GetRegisterValues(), trace_file,
IsHeapObject(function_)
? function_->shared()
->internal_formal_parameter_count_without_receiver()
: 0,
actual_argument_count_ - kJSArgcReceiverSlots);
bytecode_offset_in_outermost_frame_ =
translated_state_.frames()[0].bytecode_offset();
// Do the input frame to output frame(s) translation.
size_t count = translated_state_.frames().size();
if (is_restart_frame()) {
// If the debugger requested to restart a particular frame, only materialize
// up to that frame.
count = restart_frame_index_ + 1;
} else if (deoptimizing_throw_) {
// If we are supposed to go to the catch handler, find the catching frame
// for the catch and make sure we only deoptimize up to that frame.
size_t catch_handler_frame_index = count;
for (size_t i = count; i-- > 0;) {
catch_handler_pc_offset_ = LookupCatchHandler(
isolate(), &(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] {};
output_count_ = static_cast<int>(count);
// Translate each output frame.
int frame_index = 0;
size_t total_output_frame_size = 0;
for (size_t i = 0; i < count; ++i, ++frame_index) {
TranslatedFrame* translated_frame = &(translated_state_.frames()[i]);
const bool handle_exception = deoptimizing_throw_ && i == count - 1;
switch (translated_frame->kind()) {
case TranslatedFrame::kUnoptimizedFunction:
DoComputeUnoptimizedFrame(translated_frame, frame_index,
handle_exception);
break;
case TranslatedFrame::kInlinedExtraArguments:
DoComputeInlinedExtraArguments(translated_frame, frame_index);
break;
case TranslatedFrame::kConstructCreateStub:
DoComputeConstructCreateStubFrame(translated_frame, frame_index);
break;
case TranslatedFrame::kConstructInvokeStub:
DoComputeConstructInvokeStubFrame(translated_frame, frame_index);
break;
case TranslatedFrame::kBuiltinContinuation:
#if V8_ENABLE_WEBASSEMBLY
case TranslatedFrame::kJSToWasmBuiltinContinuation:
#endif // V8_ENABLE_WEBASSEMBLY
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;
#if V8_ENABLE_WEBASSEMBLY
case TranslatedFrame::kWasmInlinedIntoJS:
FATAL("inlined wasm frames may not appear in JS deopts");
case TranslatedFrame::kLiftoffFunction:
FATAL("wasm liftoff frames may not appear in JS deopts");
#endif
case TranslatedFrame::kInvalid:
FATAL("invalid frame");
}
total_output_frame_size += output_[frame_index]->GetFrameSize();
}
FrameDescription* topmost = output_[count - 1];
topmost->GetRegisterValues()->SetRegister(kRootRegister.code(),
isolate()->isolate_root());
#ifdef V8_COMPRESS_POINTERS
topmost->GetRegisterValues()->SetRegister(kPtrComprCageBaseRegister.code(),
isolate()->cage_base());
#endif
// Don't reset the tiering state for OSR code since we might reuse OSR code
// after deopt, and we still want to tier up to non-OSR code even if OSR code
// deoptimized.
bool osr_early_exit = Deoptimizer::GetDeoptInfo().deopt_reason ==
DeoptimizeReason::kOSREarlyExit;
// TODO(saelo): We have to use full pointer comparisons here while not all
// Code objects have been migrated into trusted space.
static_assert(!kAllCodeObjectsLiveInTrustedSpace);
if (IsJSFunction(function_) &&
(compiled_code_->osr_offset().IsNone()
? function_->code(isolate()).SafeEquals(compiled_code_)
: (!osr_early_exit &&
DeoptExitIsInsideOsrLoop(isolate(), function_,
bytecode_offset_in_outermost_frame_,
compiled_code_->osr_offset())))) {
function_->reset_tiering_state();
function_->SetInterruptBudget(isolate_, CodeKind::INTERPRETED_FUNCTION);
}
// Print some helpful diagnostic information.
if (verbose_tracing_enabled()) {
TraceDeoptEnd(timer.Elapsed().InMillisecondsF());
}
// 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);
}
// static
bool Deoptimizer::DeoptExitIsInsideOsrLoop(Isolate* isolate,
Tagged<JSFunction> function,
BytecodeOffset deopt_exit_offset,
BytecodeOffset osr_offset) {
DisallowGarbageCollection no_gc;
HandleScope scope(isolate);
DCHECK(!deopt_exit_offset.IsNone());
DCHECK(!osr_offset.IsNone());
Handle<BytecodeArray> bytecode_array(
function->shared()->GetBytecodeArray(isolate), isolate);
DCHECK(interpreter::BytecodeArrayIterator::IsValidOffset(
bytecode_array, deopt_exit_offset.ToInt()));
interpreter::BytecodeArrayIterator it(bytecode_array, osr_offset.ToInt());
DCHECK_EQ(it.current_bytecode(), interpreter::Bytecode::kJumpLoop);
for (; !it.done(); it.Advance()) {
const int current_offset = it.current_offset();
// If we've reached the deopt exit, it's contained in the current loop
// (this is covered by IsInRange below, but this check lets us avoid
// useless iteration).
if (current_offset == deopt_exit_offset.ToInt()) return true;
// We're only interested in loop ranges.
if (it.current_bytecode() != interpreter::Bytecode::kJumpLoop) continue;
// Is the deopt exit contained in the current loop?
if (base::IsInRange(deopt_exit_offset.ToInt(), it.GetJumpTargetOffset(),
current_offset)) {
return true;
}
// We've reached nesting level 0, i.e. the current JumpLoop concludes a
// top-level loop.
const int loop_nesting_level = it.GetImmediateOperand(1);
if (loop_nesting_level == 0) return false;
}
UNREACHABLE();
}
namespace {
// Get the dispatch builtin for unoptimized frames.
Builtin DispatchBuiltinFor(bool deopt_to_baseline, bool advance_bc,
bool is_restart_frame) {
if (is_restart_frame) return Builtin::kRestartFrameTrampoline;
if (deopt_to_baseline) {
return advance_bc ? Builtin::kBaselineOrInterpreterEnterAtNextBytecode
: Builtin::kBaselineOrInterpreterEnterAtBytecode;
} else {
return advance_bc ? Builtin::kInterpreterEnterAtNextBytecode
: Builtin::kInterpreterEnterAtBytecode;
}
}
} // namespace
void Deoptimizer::DoComputeUnoptimizedFrame(TranslatedFrame* translated_frame,
int frame_index,
bool goto_catch_handler) {
Tagged<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->bytecode_offset().ToInt();
const int bytecode_offset =
goto_catch_handler ? catch_handler_pc_offset_ : real_bytecode_offset;
const int parameters_count =
shared->internal_formal_parameter_count_with_receiver();
// If this is the bottom most frame or the previous frame was the inlined
// extra arguments frame, then we already have extra arguments in the stack
// (including any extra padding). Therefore we should not try to add any
// padding.
bool should_pad_arguments =
!is_bottommost && (translated_state_.frames()[frame_index - 1]).kind() !=
TranslatedFrame::kInlinedExtraArguments;
const int locals_count = translated_frame->height();
UnoptimizedFrameInfo frame_info = UnoptimizedFrameInfo::Precise(
parameters_count, locals_count, is_topmost, should_pad_arguments);
const uint32_t output_frame_size = frame_info.frame_size_in_bytes();
TranslatedFrame::iterator function_iterator = value_iterator++;
Tagged<BytecodeArray> bytecode_array;
base::Optional<Tagged<DebugInfo>> debug_info =
shared->TryGetDebugInfo(isolate());
if (debug_info.has_value() && debug_info.value()->HasBreakInfo()) {
bytecode_array = debug_info.value()->DebugBytecodeArray(isolate());
} else {
bytecode_array = shared->GetBytecodeArray(isolate());
}
// Allocate and store the output frame description.
FrameDescription* output_frame =
FrameDescription::Create(output_frame_size, parameters_count, isolate());
FrameWriter frame_writer(this, output_frame, verbose_trace_scope());
CHECK(frame_index >= 0 && frame_index < output_count_);
CHECK_NULL(output_[frame_index]);
output_[frame_index] = output_frame;
// Compute this frame's PC and state.
// For interpreted frames, the PC will be a special builtin that
// continues the bytecode dispatch. Note that non-topmost and lazy-style
// bailout handlers also advance the bytecode offset before dispatch, hence
// simulating what normal handlers do upon completion of the operation.
// For baseline frames, the PC will be a builtin to convert the interpreter
// frame to a baseline frame before continuing execution of baseline code.
// We can't directly continue into baseline code, because of CFI.
Builtins* builtins = isolate_->builtins();
const bool advance_bc =
(!is_topmost || (deopt_kind_ == DeoptimizeKind::kLazy)) &&
!goto_catch_handler;
const bool deopt_to_baseline =
shared->HasBaselineCode() && v8_flags.deopt_to_baseline;
const bool restart_frame = goto_catch_handler && is_restart_frame();
Tagged<Code> dispatch_builtin = builtins->code(
DispatchBuiltinFor(deopt_to_baseline, advance_bc, restart_frame));
if (verbose_tracing_enabled()) {
PrintF(trace_scope()->file(), " translating %s frame ",
deopt_to_baseline ? "baseline" : "interpreted");
std::unique_ptr<char[]> name = shared->DebugNameCStr();
PrintF(trace_scope()->file(), "%s", name.get());
PrintF(trace_scope()->file(), " => bytecode_offset=%d, ",
real_bytecode_offset);
PrintF(trace_scope()->file(), "variable_frame_size=%d, frame_size=%d%s\n",
frame_info.frame_size_in_bytes_without_fixed(), output_frame_size,
goto_catch_handler ? " (throw)" : "");
}
// 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 (should_pad_arguments) {
for (int i = 0; i < ArgumentPaddingSlots(parameters_count); ++i) {
frame_writer.PushRawObject(roots.the_hole_value(), "padding\n");
}
}
if (verbose_tracing_enabled() && is_bottommost &&
actual_argument_count_ > parameters_count) {
PrintF(trace_scope_->file(),
" -- %d extra argument(s) already in the stack --\n",
actual_argument_count_ - parameters_count);
}
frame_writer.PushStackJSArguments(value_iterator, parameters_count);
DCHECK_EQ(output_frame->GetLastArgumentSlotOffset(should_pad_arguments),
frame_writer.top_offset());
if (verbose_tracing_enabled()) {
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 bytecode offset of the bailout.
if (is_bottommost) {
frame_writer.PushBottommostCallerPc(caller_pc_);
} else {
frame_writer.PushApprovedCallerPc(output_[frame_index - 1]->GetPc());
}
// 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 = UnoptimizedFrame::fp_register();
output_frame->SetRegister(fp_reg.code(), fp_value);
}
if (V8_EMBEDDED_CONSTANT_POOL_BOOL) {
// 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.
frame_writer.PushTranslatedValue(context_pos, "context");
// The function was mentioned explicitly in the BEGIN_FRAME.
frame_writer.PushTranslatedValue(function_iterator, "function");
// Actual argument count.
int argc;
if (is_bottommost) {
argc = actual_argument_count_;
} else {
TranslatedFrame::Kind previous_frame_kind =
(translated_state_.frames()[frame_index - 1]).kind();
argc = previous_frame_kind == TranslatedFrame::kInlinedExtraArguments
? output_[frame_index - 1]->parameter_count()
: parameters_count;
}
frame_writer.PushRawValue(argc, "actual argument count\n");
// Set the bytecode array pointer.
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;
Tagged<Smi> smi_bytecode_offset = Smi::FromInt(raw_bytecode_offset);
frame_writer.PushRawObject(smi_bytecode_offset, "bytecode offset\n");
// We need to materialize the closure before getting the feedback vector.
frame_writer.PushFeedbackVectorForMaterialization(function_iterator);
if (verbose_tracing_enabled()) {
PrintF(trace_scope()->file(), " -------------------------\n");
}
// Translate the rest of the interpreter registers in the frame.
// The return_value_offset is counted from the top. Here, we compute the
// register index (counted from the start).
const int return_value_first_reg =
locals_count - translated_frame->return_value_offset();
const int return_value_count = translated_frame->return_value_count();
for (int i = 0; i < locals_count; ++i, ++value_iterator) {
// Ensure we write the return value if we have one and we are returning
// normally to a lazy deopt point.
if (is_topmost && !goto_catch_handler &&
deopt_kind_ == DeoptimizeKind::kLazy && i >= return_value_first_reg &&
i < return_value_first_reg + return_value_count) {
const int return_index = i - return_value_first_reg;
if (return_index == 0) {
frame_writer.PushRawValue(input_->GetRegister(kReturnRegister0.code()),
"return value 0\n");
// We do not handle the situation when one return value should go into
// the accumulator and another one into an ordinary register. Since
// the interpreter should never create such situation, just assert
// this does not happen.
CHECK_LE(return_value_first_reg + return_value_count, locals_count);
} else {
CHECK_EQ(return_index, 1);
frame_writer.PushRawValue(input_->GetRegister(kReturnRegister1.code()),
"return value 1\n");
}
} else {
// This is not return value, just write the value from the translations.
frame_writer.PushTranslatedValue(value_iterator, "stack parameter");
}
}
uint32_t register_slots_written = static_cast<uint32_t>(locals_count);
DCHECK_LE(register_slots_written, frame_info.register_stack_slot_count());
// Some architectures must pad the stack frame with extra stack slots
// to ensure the stack frame is aligned. Do this now.
while (register_slots_written < frame_info.register_stack_slot_count()) {
register_slots_written++;
frame_writer.PushRawObject(roots.the_hole_value(), "padding\n");
}
// Translate the accumulator register (depending on frame position).
if (is_topmost) {
for (int i = 0; i < ArgumentPaddingSlots(1); ++i) {
frame_writer.PushRawObject(roots.the_hole_value(), "padding\n");
}
// For topmost frame, put the accumulator on the stack. The
// {NotifyDeoptimized} builtin pops it off the topmost frame (possibly
// after materialization).
if (goto_catch_handler) {
// If we are lazy deopting to a catch handler, we set the accumulator to
// the exception (which lives in the result register).
intptr_t accumulator_value =
input_->GetRegister(kInterpreterAccumulatorRegister.code());
frame_writer.PushRawObject(Tagged<Object>(accumulator_value),
"accumulator\n");
} else {
// If we are lazily deoptimizing make sure we store the deopt
// return value into the appropriate slot.
if (deopt_kind_ == DeoptimizeKind::kLazy &&
translated_frame->return_value_offset() == 0 &&
translated_frame->return_value_count() > 0) {
CHECK_EQ(translated_frame->return_value_count(), 1);
frame_writer.PushRawValue(input_->GetRegister(kReturnRegister0.code()),
"return value 0\n");
} else {
frame_writer.PushTranslatedValue(value_iterator, "accumulator");
}
}
++value_iterator; // Move over the accumulator.
} else {
// For non-topmost frames, skip the accumulator translation. For those
// frames, the return value from the callee will become the accumulator.
++value_iterator;
}
CHECK_EQ(translated_frame->end(), value_iterator);
CHECK_EQ(0u, frame_writer.top_offset());
const intptr_t pc =
static_cast<intptr_t>(dispatch_builtin->instruction_start());
if (is_topmost) {
// Only the pc of the topmost frame needs to be signed since it is
// authenticated at the end of the DeoptimizationEntry builtin.
const intptr_t top_most_pc = PointerAuthentication::SignAndCheckPC(
isolate(), pc, frame_writer.frame()->GetTop());
output_frame->SetPc(top_most_pc);
} else {
output_frame->SetPc(pc);
}
// Update constant pool.
if (V8_EMBEDDED_CONSTANT_POOL_BOOL) {
intptr_t constant_pool_value =
static_cast<intptr_t>(dispatch_builtin->constant_pool());
output_frame->SetConstantPool(constant_pool_value);
if (is_topmost) {
Register constant_pool_reg =
UnoptimizedFrame::constant_pool_pointer_register();
output_frame->SetRegister(constant_pool_reg.code(), constant_pool_value);
}
}
// Clear the context register. The context might be a de-materialized object
// and will be materialized by {Runtime_NotifyDeoptimized}. For additional
// safety we use Tagged<Smi>(0) instead of the potential {arguments_marker}
// here.
if (is_topmost) {
intptr_t context_value = static_cast<intptr_t>(Smi::zero().ptr());
Register context_reg = JavaScriptFrame::context_register();
output_frame->SetRegister(context_reg.code(), context_value);
// Set the continuation for the topmost frame.
Tagged<Code> continuation = builtins->code(Builtin::kNotifyDeoptimized);
output_frame->SetContinuation(
static_cast<intptr_t>(continuation->instruction_start()));
}
}
void Deoptimizer::DoComputeInlinedExtraArguments(
TranslatedFrame* translated_frame, int frame_index) {
// Inlined arguments frame can not be the topmost, nor the bottom most frame.
CHECK(frame_index < output_count_ - 1);
CHECK_GT(frame_index, 0);
CHECK_NULL(output_[frame_index]);
// During deoptimization we need push the extra arguments of inlined functions
// (arguments with index greater than the formal parameter count).
// For more info, see the design document:
// https://docs.google.com/document/d/150wGaUREaZI6YWqOQFD5l2mWQXaPbbZjcAIJLOFrzMs
TranslatedFrame::iterator value_iterator = translated_frame->begin();
const int argument_count_without_receiver = translated_frame->height() - 1;
const int formal_parameter_count =
translated_frame->raw_shared_info()
->internal_formal_parameter_count_without_receiver();
const int extra_argument_count =
argument_count_without_receiver - formal_parameter_count;
// The number of pushed arguments is the maximum of the actual argument count
// and the formal parameter count + the receiver.
const int padding = ArgumentPaddingSlots(
std::max(argument_count_without_receiver, formal_parameter_count) + 1);
const int output_frame_size =
(std::max(0, extra_argument_count) + padding) * kSystemPointerSize;
if (verbose_tracing_enabled()) {
PrintF(trace_scope_->file(),
" translating inlined arguments frame => variable_size=%d\n",
output_frame_size);
}
// Allocate and store the output frame description.
FrameDescription* output_frame = FrameDescription::Create(
output_frame_size, JSParameterCount(argument_count_without_receiver),
isolate());
// The top address of the frame is computed from the previous frame's top and
// this frame's size.
const intptr_t top_address =
output_[frame_index - 1]->GetTop() - output_frame_size;
output_frame->SetTop(top_address);
// This is not a real frame, we take PC and FP values from the parent frame.
output_frame->SetPc(output_[frame_index - 1]->GetPc());
output_frame->SetFp(output_[frame_index - 1]->GetFp());
output_[frame_index] = output_frame;
FrameWriter frame_writer(this, output_frame, verbose_trace_scope());
ReadOnlyRoots roots(isolate());
for (int i = 0; i < padding; ++i) {
frame_writer.PushRawObject(roots.the_hole_value(), "padding\n");
}
if (extra_argument_count > 0) {
// The receiver and arguments with index below the formal parameter
// count are in the fake adaptor frame, because they are used to create the
// arguments object. We should however not push them, since the interpreter
// frame will do that.
value_iterator++; // Skip function.
value_iterator++; // Skip receiver.
for (int i = 0; i < formal_parameter_count; i++) value_iterator++;
frame_writer.PushStackJSArguments(value_iterator, extra_argument_count);
}
}
void Deoptimizer::DoComputeConstructCreateStubFrame(
TranslatedFrame* translated_frame, int frame_index) {
TranslatedFrame::iterator value_iterator = translated_frame->begin();
const bool is_topmost = (output_count_ - 1 == frame_index);
// The construct frame could become topmost only if we inlined a constructor
// call which does a tail call (otherwise the tail callee's frame would be
// the topmost one). So it could only be the DeoptimizeKind::kLazy case.
CHECK(!is_topmost || deopt_kind_ == DeoptimizeKind::kLazy);
DCHECK_EQ(translated_frame->kind(), TranslatedFrame::kConstructCreateStub);
const int parameters_count = translated_frame->height();
ConstructStubFrameInfo frame_info =
ConstructStubFrameInfo::Precise(parameters_count, is_topmost);
const uint32_t output_frame_size = frame_info.frame_size_in_bytes();
TranslatedFrame::iterator function_iterator = value_iterator++;
if (verbose_tracing_enabled()) {
PrintF(trace_scope()->file(),
" translating construct create stub => variable_frame_size=%d, "
"frame_size=%d\n",
frame_info.frame_size_in_bytes_without_fixed(), output_frame_size);
}
// Allocate and store the output frame description.
FrameDescription* output_frame =
FrameDescription::Create(output_frame_size, parameters_count, isolate());
FrameWriter frame_writer(this, output_frame, verbose_trace_scope());
DCHECK(frame_index > 0 && frame_index < output_count_);
DCHECK_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 =
output_[frame_index - 1]->GetTop() - output_frame_size;
output_frame->SetTop(top_address);
ReadOnlyRoots roots(isolate());
for (int i = 0; i < ArgumentPaddingSlots(parameters_count); ++i) {
frame_writer.PushRawObject(roots.the_hole_value(), "padding\n");
}
// The allocated receiver of a construct stub frame is passed as the
// receiver parameter through the translation. It might be encoding
// a captured object, so we need save it for later.
TranslatedFrame::iterator receiver_iterator = value_iterator;
// Compute the incoming parameter translation.
frame_writer.PushStackJSArguments(value_iterator, parameters_count);
DCHECK_EQ(output_frame->GetLastArgumentSlotOffset(),
frame_writer.top_offset());
// Read caller's PC from the previous frame.
const intptr_t caller_pc = output_[frame_index - 1]->GetPc();
frame_writer.PushApprovedCallerPc(caller_pc);
// Read caller's FP from the previous frame, and set this frame's FP.
const intptr_t 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 = JavaScriptFrame::fp_register();
output_frame->SetRegister(fp_reg.code(), fp_value);
}
if (V8_EMBEDDED_CONSTANT_POOL_BOOL) {
// Read the caller's constant pool from the previous frame.
const intptr_t caller_cp = output_[frame_index - 1]->GetConstantPool();
frame_writer.PushCallerConstantPool(caller_cp);
}
// A marker value is used to mark the frame.
intptr_t marker = StackFrame::TypeToMarker(StackFrame::CONSTRUCT);
frame_writer.PushRawValue(marker, "context (construct stub sentinel)\n");
frame_writer.PushTranslatedValue(value_iterator++, "context");
// Number of incoming arguments.
const uint32_t argc = parameters_count;
frame_writer.PushRawObject(Smi::FromInt(argc), "argc\n");
// The constructor function was mentioned explicitly in the
// CONSTRUCT_STUB_FRAME.
frame_writer.PushTranslatedValue(function_iterator, "constructor function\n");
// The deopt info contains the implicit receiver or the new target at the
// position of the receiver. Copy it to the top of stack, with the hole value
// as padding to maintain alignment.
frame_writer.PushRawObject(roots.the_hole_value(), "padding\n");
frame_writer.PushTranslatedValue(receiver_iterator, "new target\n");
if (is_topmost) {
for (int i = 0; i < ArgumentPaddingSlots(1); ++i) {
frame_writer.PushRawObject(roots.the_hole_value(), "padding\n");
}
// Ensure the result is restored back when we return to the stub.
Register result_reg = kReturnRegister0;
intptr_t result = input_->GetRegister(result_reg.code());
frame_writer.PushRawValue(result, "subcall result\n");
}
CHECK_EQ(translated_frame->end(), value_iterator);
CHECK_EQ(0u, frame_writer.top_offset());
// Compute this frame's PC.
Tagged<Code> construct_stub =
isolate_->builtins()->code(Builtin::kJSConstructStubGeneric);
Address start = construct_stub->instruction_start();
const int pc_offset =
isolate_->heap()->construct_stub_create_deopt_pc_offset().value();
intptr_t pc_value = static_cast<intptr_t>(start + pc_offset);
if (is_topmost) {
// Only the pc of the topmost frame needs to be signed since it is
// authenticated at the end of the DeoptimizationEntry builtin.
output_frame->SetPc(PointerAuthentication::SignAndCheckPC(
isolate(), pc_value, frame_writer.frame()->GetTop()));
} else {
output_frame->SetPc(pc_value);
}
// Update constant pool.
if (V8_EMBEDDED_CONSTANT_POOL_BOOL) {
intptr_t constant_pool_value =
static_cast<intptr_t>(construct_stub->constant_pool());
output_frame->SetConstantPool(constant_pool_value);
if (is_topmost) {
Register constant_pool_reg =
JavaScriptFrame::constant_pool_pointer_register();
output_frame->SetRegister(constant_pool_reg.code(), constant_pool_value);
}
}
// Clear the context register. The context might be a de-materialized object
// and will be materialized by {Runtime_NotifyDeoptimized}. For additional
// safety we use Tagged<Smi>(0) instead of the potential {arguments_marker}
// here.
if (is_topmost) {
intptr_t context_value = static_cast<intptr_t>(Smi::zero().ptr());
Register context_reg = JavaScriptFrame::context_register();
output_frame->SetRegister(context_reg.code(), context_value);
// Set the continuation for the topmost frame.
DCHECK_EQ(DeoptimizeKind::kLazy, deopt_kind_);
Tagged<Code> continuation =
isolate_->builtins()->code(Builtin::kNotifyDeoptimized);
output_frame->SetContinuation(
static_cast<intptr_t>(continuation->instruction_start()));
}
}
void Deoptimizer::DoComputeConstructInvokeStubFrame(
TranslatedFrame* translated_frame, int frame_index) {
TranslatedFrame::iterator value_iterator = translated_frame->begin();
const bool is_topmost = (output_count_ - 1 == frame_index);
// The construct frame could become topmost only if we inlined a constructor
// call which does a tail call (otherwise the tail callee's frame would be
// the topmost one). So it could only be the DeoptimizeKind::kLazy case.
CHECK(!is_topmost || deopt_kind_ == DeoptimizeKind::kLazy);
DCHECK_EQ(translated_frame->kind(), TranslatedFrame::kConstructInvokeStub);
DCHECK_EQ(translated_frame->height(), 0);
FastConstructStubFrameInfo frame_info =
FastConstructStubFrameInfo::Precise(is_topmost);
const uint32_t output_frame_size = frame_info.frame_size_in_bytes();
if (verbose_tracing_enabled()) {
PrintF(trace_scope()->file(),
" translating construct invoke stub => variable_frame_size=%d, "
"frame_size=%d\n",
frame_info.frame_size_in_bytes_without_fixed(), output_frame_size);
}
// Allocate and store the output frame description.
FrameDescription* output_frame =
FrameDescription::Create(output_frame_size, 0, isolate());
FrameWriter frame_writer(this, output_frame, verbose_trace_scope());
DCHECK(frame_index > 0 && frame_index < output_count_);
DCHECK_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 =
output_[frame_index - 1]->GetTop() - output_frame_size;
output_frame->SetTop(top_address);
// The allocated receiver of a construct stub frame is passed as the
// receiver parameter through the translation. It might be encoding
// a captured object, so we need save it for later.
TranslatedFrame::iterator receiver_iterator = value_iterator;
value_iterator++;
// Read caller's PC from the previous frame.
const intptr_t caller_pc = output_[frame_index - 1]->GetPc();
frame_writer.PushApprovedCallerPc(caller_pc);
// Read caller's FP from the previous frame, and set this frame's FP.
const intptr_t 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 = JavaScriptFrame::fp_register();
output_frame->SetRegister(fp_reg.code(), fp_value);
}
if (V8_EMBEDDED_CONSTANT_POOL_BOOL) {
// Read the caller's constant pool from the previous frame.
const intptr_t caller_cp = output_[frame_index - 1]->GetConstantPool();
frame_writer.PushCallerConstantPool(caller_cp);
}
intptr_t marker = StackFrame::TypeToMarker(StackFrame::FAST_CONSTRUCT);
frame_writer.PushRawValue(marker, "fast construct stub sentinel\n");
frame_writer.PushTranslatedValue(value_iterator++, "context");
frame_writer.PushTranslatedValue(receiver_iterator, "implicit receiver");
// The FastConstructFrame needs to be aligned in some architectures.
ReadOnlyRoots roots(isolate());
for (int i = 0; i < ArgumentPaddingSlots(1); ++i) {
frame_writer.PushRawObject(roots.the_hole_value(), "padding\n");
}
if (is_topmost) {
for (int i = 0; i < ArgumentPaddingSlots(1); ++i) {
frame_writer.PushRawObject(roots.the_hole_value(), "padding\n");
}
// Ensure the result is restored back when we return to the stub.
Register result_reg = kReturnRegister0;
intptr_t result = input_->GetRegister(result_reg.code());
frame_writer.PushRawValue(result, "subcall result\n");
}
CHECK_EQ(translated_frame->end(), value_iterator);
CHECK_EQ(0u, frame_writer.top_offset());
// Compute this frame's PC.
Tagged<Code> construct_stub = isolate_->builtins()->code(
Builtin::kInterpreterPushArgsThenFastConstructFunction);
Address start = construct_stub->instruction_start();
const int pc_offset =
isolate_->heap()->construct_stub_invoke_deopt_pc_offset().value();
intptr_t pc_value = static_cast<intptr_t>(start + pc_offset);
if (is_topmost) {
// Only the pc of the topmost frame needs to be signed since it is
// authenticated at the end of the DeoptimizationEntry builtin.
output_frame->SetPc(PointerAuthentication::SignAndCheckPC(
isolate(), pc_value, frame_writer.frame()->GetTop()));
} else {
output_frame->SetPc(pc_value);
}
// Update constant pool.
if (V8_EMBEDDED_CONSTANT_POOL_BOOL) {
intptr_t constant_pool_value =
static_cast<intptr_t>(construct_stub->constant_pool());
output_frame->SetConstantPool(constant_pool_value);
if (is_topmost) {
Register constant_pool_reg =
JavaScriptFrame::constant_pool_pointer_register();
output_frame->SetRegister(constant_pool_reg.code(), constant_pool_value);
}
}
// Clear the context register. The context might be a de-materialized object
// and will be materialized by {Runtime_NotifyDeoptimized}. For additional
// safety we use Tagged<Smi>(0) instead of the potential {arguments_marker}
// here.
if (is_topmost) {
intptr_t context_value = static_cast<intptr_t>(Smi::zero().ptr());
Register context_reg = JavaScriptFrame::context_register();
output_frame->SetRegister(context_reg.code(), context_value);
// Set the continuation for the topmost frame.
DCHECK_EQ(DeoptimizeKind::kLazy, deopt_kind_);
Tagged<Code> continuation =
isolate_->builtins()->code(Builtin::kNotifyDeoptimized);
output_frame->SetContinuation(
static_cast<intptr_t>(continuation->instruction_start()));
}
}
namespace {
bool BuiltinContinuationModeIsJavaScript(BuiltinContinuationMode mode) {
switch (mode) {
case BuiltinContinuationMode::STUB:
return false;
case BuiltinContinuationMode::JAVASCRIPT:
case BuiltinContinuationMode::JAVASCRIPT_WITH_CATCH:
case BuiltinContinuationMode::JAVASCRIPT_HANDLE_EXCEPTION:
return true;
}
UNREACHABLE();
}
StackFrame::Type BuiltinContinuationModeToFrameType(
BuiltinContinuationMode mode) {
switch (mode) {
case BuiltinContinuationMode::STUB:
return StackFrame::BUILTIN_CONTINUATION;
case BuiltinContinuationMode::JAVASCRIPT:
return StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION;
case BuiltinContinuationMode::JAVASCRIPT_WITH_CATCH:
return StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION_WITH_CATCH;
case BuiltinContinuationMode::JAVASCRIPT_HANDLE_EXCEPTION:
return StackFrame::JAVA_SCRIPT_BUILTIN_CONTINUATION_WITH_CATCH;
}
UNREACHABLE();
}
} // namespace
Builtin Deoptimizer::TrampolineForBuiltinContinuation(
BuiltinContinuationMode mode, bool must_handle_result) {
switch (mode) {
case BuiltinContinuationMode::STUB:
return must_handle_result ? Builtin::kContinueToCodeStubBuiltinWithResult
: Builtin::kContinueToCodeStubBuiltin;
case BuiltinContinuationMode::JAVASCRIPT:
case BuiltinContinuationMode::JAVASCRIPT_WITH_CATCH:
case BuiltinContinuationMode::JAVASCRIPT_HANDLE_EXCEPTION:
return must_handle_result
? Builtin::kContinueToJavaScriptBuiltinWithResult
: Builtin::kContinueToJavaScriptBuiltin;
}
UNREACHABLE();
}
#if V8_ENABLE_WEBASSEMBLY
TranslatedValue Deoptimizer::TranslatedValueForWasmReturnKind(
base::Optional<wasm::ValueKind> wasm_call_return_kind) {
if (wasm_call_return_kind) {
switch (wasm_call_return_kind.value()) {
case wasm::kI32:
return TranslatedValue::NewInt32(
&translated_state_,
static_cast<int32_t>(input_->GetRegister(kReturnRegister0.code())));
case wasm::kI64:
return TranslatedValue::NewInt64ToBigInt(
&translated_state_,
static_cast<int64_t>(input_->GetRegister(kReturnRegister0.code())));
case wasm::kF32:
return TranslatedValue::NewFloat(
&translated_state_,
Float32(*reinterpret_cast<float*>(
input_->GetDoubleRegister(wasm::kFpReturnRegisters[0].code())
.get_bits_address())));
case wasm::kF64:
return TranslatedValue::NewDouble(
&translated_state_,
input_->GetDoubleRegister(wasm::kFpReturnRegisters[0].code()));
default:
UNREACHABLE();
}
}
return TranslatedValue::NewTagged(&translated_state_,
ReadOnlyRoots(isolate()).undefined_value());
}
#endif // V8_ENABLE_WEBASSEMBLY
// BuiltinContinuationFrames capture the machine state that is expected as input
// to a builtin, including both input register values and stack parameters. When
// the frame is reactivated (i.e. the frame below it returns), a
// ContinueToBuiltin stub restores the register state from the frame and tail
// calls to the actual target builtin, making it appear that the stub had been
// directly called by the frame above it. The input values to populate the frame
// are taken from the deopt's FrameState.
//
// Frame translation happens in two modes, EAGER and LAZY. In EAGER mode, all of
// the parameters to the Builtin are explicitly specified in the TurboFan
// FrameState node. In LAZY mode, there is always one fewer parameters specified
// in the FrameState than expected by the Builtin. In that case, construction of
// BuiltinContinuationFrame adds the final missing parameter during
// deoptimization, and that parameter is always on the stack and contains the
// value returned from the callee of the call site triggering the LAZY deopt
// (e.g. rax on x64). This requires that continuation Builtins for LAZY deopts
// must have at least one stack parameter.
//
// TO
// | .... |
// +-------------------------+
// | arg padding (arch dept) |<- at most 1*kSystemPointerSize
// +-------------------------+
// | builtin param 0 |<- FrameState input value n becomes
// +-------------------------+
// | ... |
// +-------------------------+
// | builtin param m |<- FrameState input value n+m-1, or in
// +-----needs-alignment-----+ the LAZY case, return LAZY result value
// | ContinueToBuiltin entry |
// +-------------------------+
// | | saved frame (FP) |
// | +=====needs=alignment=====+<- fpreg
// | |constant pool (if ool_cp)|
// v +-------------------------+
// |BUILTIN_CONTINUATION mark|
// +-------------------------+
// | JSFunction (or zero) |<- only if JavaScript builtin
// +-------------------------+
// | frame height above FP |
// +-------------------------+
// | context |<- this non-standard context slot contains
// +-------------------------+ the context, even for non-JS builtins.
// | builtin index |
// +-------------------------+
// | builtin input GPR reg0 |<- populated from deopt FrameState using
// +-------------------------+ the builtin's CallInterfaceDescriptor
// | ... | to map a FrameState's 0..n-1 inputs to
// +-------------------------+ the builtin's n input register params.
// | builtin input GPR regn |
// +-------------------------+
// | reg padding (arch dept) |
// +-----needs--alignment----+
// | res padding (arch dept) |<- only if {is_topmost}; result is pop'd by
// +-------------------------+<- kNotifyDeopt ASM stub and moved to acc
// | result value |<- reg, as ContinueToBuiltin stub expects.
// +-----needs-alignment-----+<- spreg
//
void Deoptimizer::DoComputeBuiltinContinuation(
TranslatedFrame* translated_frame, int frame_index,
BuiltinContinuationMode mode) {
TranslatedFrame::iterator result_iterator = translated_frame->end();
bool is_js_to_wasm_builtin_continuation = false;
#if V8_ENABLE_WEBASSEMBLY
is_js_to_wasm_builtin_continuation =
translated_frame->kind() == TranslatedFrame::kJSToWasmBuiltinContinuation;
if (is_js_to_wasm_builtin_continuation) {
// For JSToWasmBuiltinContinuations, add a TranslatedValue with the result
// of the Wasm call, extracted from the input FrameDescription.
// This TranslatedValue will be written in the output frame in place of the
// hole and we'll use ContinueToCodeStubBuiltin in place of
// ContinueToCodeStubBuiltinWithResult.
TranslatedValue result = TranslatedValueForWasmReturnKind(
translated_frame->wasm_call_return_kind());
translated_frame->Add(result);
}
#endif // V8_ENABLE_WEBASSEMBLY
TranslatedFrame::iterator value_iterator = translated_frame->begin();
const BytecodeOffset bytecode_offset = translated_frame->bytecode_offset();
Builtin builtin = Builtins::GetBuiltinFromBytecodeOffset(bytecode_offset);
CallInterfaceDescriptor continuation_descriptor =
Builtins::CallInterfaceDescriptorFor(builtin);
const RegisterConfiguration* config = RegisterConfiguration::Default();
const bool is_bottommost = (0 == frame_index);
const bool is_topmost = (output_count_ - 1 == frame_index);
const int parameters_count = translated_frame->height();
BuiltinContinuationFrameInfo frame_info =
BuiltinContinuationFrameInfo::Precise(parameters_count,
continuation_descriptor, config,
is_topmost, deopt_kind_, mode);
const unsigned output_frame_size = frame_info.frame_size_in_bytes();
const unsigned output_frame_size_above_fp =
frame_info.frame_size_in_bytes_above_fp();
// Validate types of parameters. They must all be tagged except for argc for
// JS builtins.
bool has_argc = false;
const int register_parameter_count =
continuation_descriptor.GetRegisterParameterCount();
for (int i = 0; i < register_parameter_count; ++i) {
MachineType type = continuation_descriptor.GetParameterType(i);
int code = continuation_descriptor.GetRegisterParameter(i).code();
// Only tagged and int32 arguments are supported, and int32 only for the
// arguments count on JavaScript builtins.
if (type == MachineType::Int32()) {
CHECK_EQ(code, kJavaScriptCallArgCountRegister.code());
has_argc = true;
} else {
// Any other argument must be a tagged value.
CHECK(IsAnyTagged(type.representation()));
}
}
CHECK_EQ(BuiltinContinuationModeIsJavaScript(mode), has_argc);
if (verbose_tracing_enabled()) {
PrintF(trace_scope()->file(),
" translating BuiltinContinuation to %s,"
" => register_param_count=%d,"
" stack_param_count=%d, frame_size=%d\n",
Builtins::name(builtin), register_parameter_count,
frame_info.stack_parameter_count(), output_frame_size);
}
FrameDescription* output_frame = FrameDescription::Create(
output_frame_size, frame_info.stack_parameter_count(), isolate());
output_[frame_index] = output_frame;
FrameWriter frame_writer(this, output_frame, verbose_trace_scope());
// 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);
// Get the possible JSFunction for the case that this is a
// JavaScriptBuiltinContinuationFrame, which needs the JSFunction pointer
// like a normal JavaScriptFrame.
const intptr_t maybe_function = value_iterator->GetRawValue().ptr();
++value_iterator;
ReadOnlyRoots roots(isolate());
const int padding = ArgumentPaddingSlots(frame_info.stack_parameter_count());
for (int i = 0; i < padding; ++i) {
frame_writer.PushRawObject(roots.the_hole_value(), "padding\n");
}
if (mode == BuiltinContinuationMode::STUB) {
DCHECK_EQ(
Builtins::CallInterfaceDescriptorFor(builtin).GetStackArgumentOrder(),
StackArgumentOrder::kDefault);
for (uint32_t i = 0; i < frame_info.translated_stack_parameter_count();
++i, ++value_iterator) {
frame_writer.PushTranslatedValue(value_iterator, "stack parameter");
}
if (frame_info.frame_has_result_stack_slot()) {
if (is_js_to_wasm_builtin_continuation) {
frame_writer.PushTranslatedValue(result_iterator,
"return result on lazy deopt\n");
} else {
DCHECK_EQ(result_iterator, translated_frame->end());
frame_writer.PushRawObject(
roots.the_hole_value(),
"placeholder for return result on lazy deopt\n");
}
}
} else {
// JavaScript builtin.
if (frame_info.frame_has_result_stack_slot()) {
frame_writer.PushRawObject(
roots.the_hole_value(),
"placeholder for return result on lazy deopt\n");
}
switch (mode) {
case BuiltinContinuationMode::STUB:
UNREACHABLE();
case BuiltinContinuationMode::JAVASCRIPT:
break;
case BuiltinContinuationMode::JAVASCRIPT_WITH_CATCH: {
frame_writer.PushRawObject(roots.the_hole_value(),
"placeholder for exception on lazy deopt\n");
} break;
case BuiltinContinuationMode::JAVASCRIPT_HANDLE_EXCEPTION: {
intptr_t accumulator_value =
input_->GetRegister(kInterpreterAccumulatorRegister.code());
frame_writer.PushRawObject(Tagged<Object>(accumulator_value),
"exception (from accumulator)\n");
} break;
}
frame_writer.PushStackJSArguments(
value_iterator, frame_info.translated_stack_parameter_count());
}
DCHECK_EQ(output_frame->GetLastArgumentSlotOffset(),
frame_writer.top_offset());
std::vector<TranslatedFrame::iterator> register_values;
int total_registers = config->num_general_registers();
register_values.resize(total_registers, {value_iterator});
for (int i = 0; i < register_parameter_count; ++i, ++value_iterator) {
int code = continuation_descriptor.GetRegisterParameter(i).code();
register_values[code] = value_iterator;
}
// The context register is always implicit in the CallInterfaceDescriptor but
// its register must be explicitly set when continuing to the builtin. Make
// sure that it's harvested from the translation and copied into the register
// set (it was automatically added at the end of the FrameState by the
// instruction selector).
Tagged<Object> context = value_iterator->GetRawValue();
const intptr_t value = context.ptr();
TranslatedFrame::iterator context_register_value = value_iterator++;
register_values[kContextRegister.code()] = context_register_value;
output_frame->SetRegister(kContextRegister.code(), value);
// Set caller's PC (JSFunction continuation).
if (is_bottommost) {
frame_writer.PushBottommostCallerPc(caller_pc_);
} else {
frame_writer.PushApprovedCallerPc(output_[frame_index - 1]->GetPc());
}
// Read caller's FP from the previous frame, and set this frame's FP.
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);
DCHECK_EQ(output_frame_size_above_fp, frame_writer.top_offset());
if (V8_EMBEDDED_CONSTANT_POOL_BOOL) {
// Read the caller's constant pool from the previous frame.
const intptr_t caller_cp =
is_bottommost ? caller_constant_pool_
: output_[frame_index - 1]->GetConstantPool();
frame_writer.PushCallerConstantPool(caller_cp);
}
// A marker value is used in place of the context.
const intptr_t marker =
StackFrame::TypeToMarker(BuiltinContinuationModeToFrameType(mode));
frame_writer.PushRawValue(marker,
"context (builtin continuation sentinel)\n");
if (BuiltinContinuationModeIsJavaScript(mode)) {
frame_writer.PushRawValue(maybe_function, "JSFunction\n");
} else {
frame_writer.PushRawValue(0, "unused\n");
}
// The delta from the SP to the FP; used to reconstruct SP in
// Isolate::UnwindAndFindHandler.
frame_writer.PushRawObject(Smi::FromInt(output_frame_size_above_fp),
"frame height at deoptimization\n");
// The context even if this is a stub continuation frame. We can't use the
// usual context slot, because we must store the frame marker there.
frame_writer.PushTranslatedValue(context_register_value,
"builtin JavaScript context\n");
// The builtin to continue to.
frame_writer.PushRawObject(Smi::FromInt(static_cast<int>(builtin)),
"builtin index\n");
const int allocatable_register_count =
config->num_allocatable_general_registers();
for (int i = 0; i < allocatable_register_count; ++i) {
int code = config->GetAllocatableGeneralCode(i);
base::ScopedVector<char> str(128);
if (verbose_tracing_enabled()) {
if (BuiltinContinuationModeIsJavaScript(mode) &&
code == kJavaScriptCallArgCountRegister.code()) {
SNPrintF(
str,
"tagged argument count %s (will be untagged by continuation)\n",
RegisterName(Register::from_code(code)));
} else {
SNPrintF(str, "builtin register argument %s\n",
RegisterName(Register::from_code(code)));
}
}
frame_writer.PushTranslatedValue(
register_values[code], verbose_tracing_enabled() ? str.begin() : "");
}
// Some architectures must pad the stack frame with extra stack slots
// to ensure the stack frame is aligned.
const int padding_slot_count =
BuiltinContinuationFrameConstants::PaddingSlotCount(
allocatable_register_count);
for (int i = 0; i < padding_slot_count; ++i) {
frame_writer.PushRawObject(roots.the_hole_value(), "padding\n");
}
if (is_topmost) {
for (int i = 0; i < ArgumentPaddingSlots(1); ++i) {
frame_writer.PushRawObject(roots.the_hole_value(), "padding\n");
}
// Ensure the result is restored back when we return to the stub.
if (frame_info.frame_has_result_stack_slot()) {
Register result_reg = kReturnRegister0;
frame_writer.PushRawValue(input_->GetRegister(result_reg.code()),
"callback result\n");
} else {
frame_writer.PushRawObject(roots.undefined_value(), "callback result\n");
}
}
CHECK_EQ(result_iterator, value_iterator);
CHECK_EQ(0u, frame_writer.top_offset());
// Clear the context register. The context might be a de-materialized object
// and will be materialized by {Runtime_NotifyDeoptimized}. For additional
// safety we use Tagged<Smi>(0) instead of the potential {arguments_marker}
// here.
if (is_topmost) {
intptr_t context_value = static_cast<intptr_t>(Smi::zero().ptr());
Register context_reg = JavaScriptFrame::context_register();
output_frame->SetRegister(context_reg.code(), context_value);
}
// Ensure the frame pointer register points to the callee's frame. The builtin
// will build its own frame once we continue to it.
Register fp_reg = JavaScriptFrame::fp_register();
output_frame->SetRegister(fp_reg.code(), fp_value);
// For JSToWasmBuiltinContinuations use ContinueToCodeStubBuiltin, and not
// ContinueToCodeStubBuiltinWithResult because we don't want to overwrite the
// return value that we have already set.
Tagged<Code> continue_to_builtin =
isolate()->builtins()->code(TrampolineForBuiltinContinuation(
mode, frame_info.frame_has_result_stack_slot() &&
!is_js_to_wasm_builtin_continuation));
if (is_topmost) {
// Only the pc of the topmost frame needs to be signed since it is
// authenticated at the end of the DeoptimizationEntry builtin.
const intptr_t top_most_pc = PointerAuthentication::SignAndCheckPC(
isolate(),
static_cast<intptr_t>(continue_to_builtin->instruction_start()),
frame_writer.frame()->GetTop());
output_frame->SetPc(top_most_pc);
} else {
output_frame->SetPc(
static_cast<intptr_t>(continue_to_builtin->instruction_start()));
}
Tagged<Code> continuation =
isolate()->builtins()->code(Builtin::kNotifyDeoptimized);
output_frame->SetContinuation(
static_cast<intptr_t>(continuation->instruction_start()));
}
void Deoptimizer::MaterializeHeapObjects() {
translated_state_.Prepare(static_cast<Address>(stack_fp_));
if (v8_flags.deopt_every_n_times > 0) {
// Doing a GC here will find problems with the deoptimized frames.
isolate_->heap()->CollectAllGarbage(GCFlag::kNoFlags,
GarbageCollectionReason::kTesting);
}
for (auto& materialization : values_to_materialize_) {
Handle<Object> value = materialization.value_->GetValue();
if (verbose_tracing_enabled()) {
PrintF(trace_scope()->file(),
"Materialization [" V8PRIxPTR_FMT "] <- " V8PRIxPTR_FMT " ; ",
static_cast<intptr_t>(materialization.output_slot_address_),
(*value).ptr());
ShortPrint(*value, trace_scope()->file());
PrintF(trace_scope()->file(), "\n");
}
*(reinterpret_cast<Address*>(materialization.output_slot_address_)) =
(*value).ptr();
}
for (auto& fbv_materialization : feedback_vector_to_materialize_) {
Handle<Object> closure = fbv_materialization.value_->GetValue();
DCHECK(IsJSFunction(*closure));
Tagged<Object> feedback_vector =
Tagged<JSFunction>::cast(*closure)->raw_feedback_cell()->value();
CHECK(IsFeedbackVector(feedback_vector));
*(reinterpret_cast<Address*>(fbv_materialization.output_slot_address_)) =
feedback_vector.ptr();
}
translated_state_.VerifyMaterializedObjects();
bool feedback_updated = translated_state_.DoUpdateFeedback();
if (verbose_tracing_enabled() && feedback_updated) {
FILE* file = trace_scope()->file();
Deoptimizer::DeoptInfo info = Deoptimizer::GetDeoptInfo();
PrintF(file, "Feedback updated from deoptimization at ");
OFStream outstr(file);
info.position.Print(outstr, compiled_code_);
PrintF(file, ", %s\n", DeoptimizeReasonToString(info.deopt_reason));
}
isolate_->materialized_object_store()->Remove(
static_cast<Address>(stack_fp_));
}
void Deoptimizer::QueueValueForMaterialization(
Address output_address, Tagged<Object> obj,
const TranslatedFrame::iterator& iterator) {
if (obj == ReadOnlyRoots(isolate_).arguments_marker()) {
values_to_materialize_.push_back({output_address, iterator});
}
}
void Deoptimizer::QueueFeedbackVectorForMaterialization(
Address output_address, const TranslatedFrame::iterator& iterator) {
feedback_vector_to_materialize_.push_back({output_address, iterator});
}
unsigned Deoptimizer::ComputeInputFrameAboveFpFixedSize() const {
unsigned fixed_size = CommonFrameConstants::kFixedFrameSizeAboveFp;
// TODO(jkummerow): If {IsSmi(function_)} can indeed be true, then
// {function_} should not have type {JSFunction}.
IF_WASM(DCHECK_IMPLIES, function_.is_null(), v8_flags.wasm_deopt);
if (!function_.is_null() && !IsSmi(function_)) {
fixed_size += ComputeIncomingArgumentSize(function_->shared());
}
return fixed_size;
}
namespace {
// Get the actual deopt call PC from the return address of the deopt, which
// points to immediately after the deopt call).
//
// See also the Deoptimizer constructor.
Address GetDeoptCallPCFromReturnPC(Address return_pc, Tagged<Code> code) {
DCHECK_GT(Deoptimizer::kEagerDeoptExitSize, 0);
DCHECK_GT(Deoptimizer::kLazyDeoptExitSize, 0);
Tagged<DeoptimizationData> deopt_data =
DeoptimizationData::cast(code->deoptimization_data());
Address deopt_start =
code->instruction_start() + deopt_data->DeoptExitStart().value();
int eager_deopt_count = deopt_data->EagerDeoptCount().value();
Address lazy_deopt_start =
deopt_start + eager_deopt_count * Deoptimizer::kEagerDeoptExitSize;
// The deoptimization exits are sorted so that lazy deopt exits appear
// after eager deopts.
static_assert(static_cast<int>(DeoptimizeKind::kLazy) ==
static_cast<int>(kLastDeoptimizeKind),
"lazy deopts are expected to be emitted last");
if (return_pc <= lazy_deopt_start) {
return return_pc - Deoptimizer::kEagerDeoptExitSize;
} else {
return return_pc - Deoptimizer::kLazyDeoptExitSize;
}
}
} // namespace
unsigned Deoptimizer::ComputeInputFrameSize() const {
// The fp-to-sp delta already takes the context, constant pool pointer and the
// function into account so we have to avoid double counting them.
unsigned fixed_size_above_fp = ComputeInputFrameAboveFpFixedSize();
unsigned result = fixed_size_above_fp + fp_to_sp_delta_;
DCHECK(CodeKindCanDeoptimize(compiled_code_->kind()));
unsigned stack_slots = compiled_code_->stack_slots();
if (compiled_code_->is_maglevved() && !deoptimizing_throw_) {
// Maglev code can deopt in deferred code which has spilled registers across
// the call. These will be included in the fp_to_sp_delta, but the expected
// frame size won't include them, so we need to check for less-equal rather
// than equal. For deoptimizing throws, these will have already been trimmed
// off.
CHECK_LE(fixed_size_above_fp + (stack_slots * kSystemPointerSize) -
CommonFrameConstants::kFixedFrameSizeAboveFp,
result);
// With slow asserts we can check this exactly, by looking up the safepoint.
if (v8_flags.enable_slow_asserts) {
Address deopt_call_pc = GetDeoptCallPCFromReturnPC(from_, compiled_code_);
MaglevSafepointTable table(isolate_, deopt_call_pc, compiled_code_);
MaglevSafepointEntry safepoint = table.FindEntry(deopt_call_pc);
unsigned extra_spills = safepoint.num_extra_spill_slots();
CHECK_EQ(fixed_size_above_fp + (stack_slots * kSystemPointerSize) -
CommonFrameConstants::kFixedFrameSizeAboveFp +
extra_spills * kSystemPointerSize,
result);
}
} else {
unsigned outgoing_size = 0;
CHECK_EQ(fixed_size_above_fp + (stack_slots * kSystemPointerSize) -
CommonFrameConstants::kFixedFrameSizeAboveFp + outgoing_size,
result);
}
return result;
}
// static
unsigned Deoptimizer::ComputeIncomingArgumentSize(
Tagged<SharedFunctionInfo> shared) {
int parameter_slots = shared->internal_formal_parameter_count_with_receiver();
return parameter_slots * kSystemPointerSize;
}
Deoptimizer::DeoptInfo Deoptimizer::GetDeoptInfo(Tagged<Code> code,
Address pc) {
CHECK(code->instruction_start() <= pc && pc <= code->instruction_end());
SourcePosition last_position = SourcePosition::Unknown();
DeoptimizeReason last_reason = DeoptimizeReason::kUnknown;
uint32_t last_node_id = 0;
int last_deopt_id = kNoDeoptimizationId;
int mask = RelocInfo::ModeMask(RelocInfo::DEOPT_REASON) |
RelocInfo::ModeMask(RelocInfo::DEOPT_ID) |
RelocInfo::ModeMask(RelocInfo::DEOPT_SCRIPT_OFFSET) |
RelocInfo::ModeMask(RelocInfo::DEOPT_INLINING_ID) |
RelocInfo::ModeMask(RelocInfo::DEOPT_NODE_ID);
for (RelocIterator it(code, mask); !it.done(); it.next()) {
RelocInfo* info = it.rinfo();
if (info->pc() >= pc) break;
if (info->rmode() == RelocInfo::DEOPT_SCRIPT_OFFSET) {
int script_offset = static_cast<int>(info->data());
it.next();
DCHECK(it.rinfo()->rmode() == RelocInfo::DEOPT_INLINING_ID);
int inlining_id = static_cast<int>(it.rinfo()->data());
last_position = SourcePosition(script_offset, inlining_id);
} else if (info->rmode() == RelocInfo::DEOPT_ID) {
last_deopt_id = static_cast<int>(info->data());
} else if (info->rmode() == RelocInfo::DEOPT_REASON) {
last_reason = static_cast<DeoptimizeReason>(info->data());
} else if (info->rmode() == RelocInfo::DEOPT_NODE_ID) {
last_node_id = static_cast<uint32_t>(info->data());
}
}
return DeoptInfo(last_position, last_reason, last_node_id, last_deopt_id);
}
} // namespace internal
} // namespace v8