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// Copyright 2011 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef V8_DEOPTIMIZER_H_
#define V8_DEOPTIMIZER_H_
#include "v8.h"
#include "allocation.h"
#include "macro-assembler.h"
#include "zone-inl.h"
namespace v8 {
namespace internal {
class FrameDescription;
class TranslationIterator;
class DeoptimizingCodeListNode;
class DeoptimizedFrameInfo;
class HeapNumberMaterializationDescriptor BASE_EMBEDDED {
public:
HeapNumberMaterializationDescriptor(Address slot_address, double val)
: slot_address_(slot_address), val_(val) { }
Address slot_address() const { return slot_address_; }
double value() const { return val_; }
private:
Address slot_address_;
double val_;
};
class OptimizedFunctionVisitor BASE_EMBEDDED {
public:
virtual ~OptimizedFunctionVisitor() {}
// Function which is called before iteration of any optimized functions
// from given global context.
virtual void EnterContext(Context* context) = 0;
virtual void VisitFunction(JSFunction* function) = 0;
// Function which is called after iteration of all optimized functions
// from given global context.
virtual void LeaveContext(Context* context) = 0;
};
class Deoptimizer;
class DeoptimizerData {
public:
DeoptimizerData();
~DeoptimizerData();
#ifdef ENABLE_DEBUGGER_SUPPORT
void Iterate(ObjectVisitor* v);
#endif
private:
LargeObjectChunk* eager_deoptimization_entry_code_;
LargeObjectChunk* lazy_deoptimization_entry_code_;
Deoptimizer* current_;
#ifdef ENABLE_DEBUGGER_SUPPORT
DeoptimizedFrameInfo* deoptimized_frame_info_;
#endif
// List of deoptimized code which still have references from active stack
// frames. These code objects are needed by the deoptimizer when deoptimizing
// a frame for which the code object for the function function has been
// changed from the code present when deoptimizing was done.
DeoptimizingCodeListNode* deoptimizing_code_list_;
friend class Deoptimizer;
DISALLOW_COPY_AND_ASSIGN(DeoptimizerData);
};
class Deoptimizer : public Malloced {
public:
enum BailoutType {
EAGER,
LAZY,
OSR,
// This last bailout type is not really a bailout, but used by the
// debugger to deoptimize stack frames to allow inspection.
DEBUGGER
};
int output_count() const { return output_count_; }
static Deoptimizer* New(JSFunction* function,
BailoutType type,
unsigned bailout_id,
Address from,
int fp_to_sp_delta,
Isolate* isolate);
static Deoptimizer* Grab(Isolate* isolate);
#ifdef ENABLE_DEBUGGER_SUPPORT
// The returned object with information on the optimized frame needs to be
// freed before another one can be generated.
static DeoptimizedFrameInfo* DebuggerInspectableFrame(JavaScriptFrame* frame,
int frame_index,
Isolate* isolate);
static void DeleteDebuggerInspectableFrame(DeoptimizedFrameInfo* info,
Isolate* isolate);
#endif
// Makes sure that there is enough room in the relocation
// information of a code object to perform lazy deoptimization
// patching. If there is not enough room a new relocation
// information object is allocated and comments are added until it
// is big enough.
static void EnsureRelocSpaceForLazyDeoptimization(Handle<Code> code);
// Deoptimize the function now. Its current optimized code will never be run
// again and any activations of the optimized code will get deoptimized when
// execution returns.
static void DeoptimizeFunction(JSFunction* function);
// Deoptimize all functions in the heap.
static void DeoptimizeAll();
static void DeoptimizeGlobalObject(JSObject* object);
static void VisitAllOptimizedFunctionsForContext(
Context* context, OptimizedFunctionVisitor* visitor);
static void VisitAllOptimizedFunctionsForGlobalObject(
JSObject* object, OptimizedFunctionVisitor* visitor);
static void VisitAllOptimizedFunctions(OptimizedFunctionVisitor* visitor);
// The size in bytes of the code required at a lazy deopt patch site.
static int patch_size();
// Patch all stack guard checks in the unoptimized code to
// unconditionally call replacement_code.
static void PatchStackCheckCode(Code* unoptimized_code,
Code* check_code,
Code* replacement_code);
// Patch stack guard check at instruction before pc_after in
// the unoptimized code to unconditionally call replacement_code.
static void PatchStackCheckCodeAt(Address pc_after,
Code* check_code,
Code* replacement_code);
// Change all patched stack guard checks in the unoptimized code
// back to a normal stack guard check.
static void RevertStackCheckCode(Code* unoptimized_code,
Code* check_code,
Code* replacement_code);
// Change all patched stack guard checks in the unoptimized code
// back to a normal stack guard check.
static void RevertStackCheckCodeAt(Address pc_after,
Code* check_code,
Code* replacement_code);
~Deoptimizer();
void MaterializeHeapNumbers();
#ifdef ENABLE_DEBUGGER_SUPPORT
void MaterializeHeapNumbersForDebuggerInspectableFrame(
Address top, uint32_t size, DeoptimizedFrameInfo* info);
#endif
static void ComputeOutputFrames(Deoptimizer* deoptimizer);
static Address GetDeoptimizationEntry(int id, BailoutType type);
static int GetDeoptimizationId(Address addr, BailoutType type);
static int GetOutputInfo(DeoptimizationOutputData* data,
unsigned node_id,
SharedFunctionInfo* shared);
// Code generation support.
static int input_offset() { return OFFSET_OF(Deoptimizer, input_); }
static int output_count_offset() {
return OFFSET_OF(Deoptimizer, output_count_);
}
static int output_offset() { return OFFSET_OF(Deoptimizer, output_); }
static int GetDeoptimizedCodeCount(Isolate* isolate);
static const int kNotDeoptimizationEntry = -1;
// Generators for the deoptimization entry code.
class EntryGenerator BASE_EMBEDDED {
public:
EntryGenerator(MacroAssembler* masm, BailoutType type)
: masm_(masm), type_(type) { }
virtual ~EntryGenerator() { }
void Generate();
protected:
MacroAssembler* masm() const { return masm_; }
BailoutType type() const { return type_; }
virtual void GeneratePrologue() { }
private:
MacroAssembler* masm_;
Deoptimizer::BailoutType type_;
};
class TableEntryGenerator : public EntryGenerator {
public:
TableEntryGenerator(MacroAssembler* masm, BailoutType type, int count)
: EntryGenerator(masm, type), count_(count) { }
protected:
virtual void GeneratePrologue();
private:
int count() const { return count_; }
int count_;
};
private:
static const int kNumberOfEntries = 4096;
Deoptimizer(Isolate* isolate,
JSFunction* function,
BailoutType type,
unsigned bailout_id,
Address from,
int fp_to_sp_delta,
Code* optimized_code);
void DeleteFrameDescriptions();
void DoComputeOutputFrames();
void DoComputeOsrOutputFrame();
void DoComputeFrame(TranslationIterator* iterator, int frame_index);
void DoTranslateCommand(TranslationIterator* iterator,
int frame_index,
unsigned output_offset);
// Translate a command for OSR. Updates the input offset to be used for
// the next command. Returns false if translation of the command failed
// (e.g., a number conversion failed) and may or may not have updated the
// input offset.
bool DoOsrTranslateCommand(TranslationIterator* iterator,
int* input_offset);
unsigned ComputeInputFrameSize() const;
unsigned ComputeFixedSize(JSFunction* function) const;
unsigned ComputeIncomingArgumentSize(JSFunction* function) const;
unsigned ComputeOutgoingArgumentSize() const;
Object* ComputeLiteral(int index) const;
void AddDoubleValue(intptr_t slot_address, double value);
static LargeObjectChunk* CreateCode(BailoutType type);
static void GenerateDeoptimizationEntries(
MacroAssembler* masm, int count, BailoutType type);
// Weak handle callback for deoptimizing code objects.
static void HandleWeakDeoptimizedCode(
v8::Persistent<v8::Value> obj, void* data);
static Code* FindDeoptimizingCodeFromAddress(Address addr);
static void RemoveDeoptimizingCode(Code* code);
// Fill the input from from a JavaScript frame. This is used when
// the debugger needs to inspect an optimized frame. For normal
// deoptimizations the input frame is filled in generated code.
void FillInputFrame(Address tos, JavaScriptFrame* frame);
Isolate* isolate_;
JSFunction* function_;
Code* optimized_code_;
unsigned bailout_id_;
BailoutType bailout_type_;
Address from_;
int fp_to_sp_delta_;
// Input frame description.
FrameDescription* input_;
// Number of output frames.
int output_count_;
// Array of output frame descriptions.
FrameDescription** output_;
List<HeapNumberMaterializationDescriptor> deferred_heap_numbers_;
static const int table_entry_size_;
friend class FrameDescription;
friend class DeoptimizingCodeListNode;
friend class DeoptimizedFrameInfo;
};
class FrameDescription {
public:
FrameDescription(uint32_t frame_size,
JSFunction* function);
void* operator new(size_t size, uint32_t frame_size) {
// Subtracts kPointerSize, as the member frame_content_ already supplies
// the first element of the area to store the frame.
return malloc(size + frame_size - kPointerSize);
}
void operator delete(void* pointer, uint32_t frame_size) {
free(pointer);
}
void operator delete(void* description) {
free(description);
}
uint32_t GetFrameSize() const {
ASSERT(static_cast<uint32_t>(frame_size_) == frame_size_);
return static_cast<uint32_t>(frame_size_);
}
JSFunction* GetFunction() const { return function_; }
unsigned GetOffsetFromSlotIndex(Deoptimizer* deoptimizer, int slot_index);
intptr_t GetFrameSlot(unsigned offset) {
return *GetFrameSlotPointer(offset);
}
double GetDoubleFrameSlot(unsigned offset) {
return *reinterpret_cast<double*>(GetFrameSlotPointer(offset));
}
void SetFrameSlot(unsigned offset, intptr_t value) {
*GetFrameSlotPointer(offset) = value;
}
intptr_t GetRegister(unsigned n) const {
ASSERT(n < ARRAY_SIZE(registers_));
return registers_[n];
}
double GetDoubleRegister(unsigned n) const {
ASSERT(n < ARRAY_SIZE(double_registers_));
return double_registers_[n];
}
void SetRegister(unsigned n, intptr_t value) {
ASSERT(n < ARRAY_SIZE(registers_));
registers_[n] = value;
}
void SetDoubleRegister(unsigned n, double value) {
ASSERT(n < ARRAY_SIZE(double_registers_));
double_registers_[n] = value;
}
intptr_t GetTop() const { return top_; }
void SetTop(intptr_t top) { top_ = top; }
intptr_t GetPc() const { return pc_; }
void SetPc(intptr_t pc) { pc_ = pc; }
intptr_t GetFp() const { return fp_; }
void SetFp(intptr_t fp) { fp_ = fp; }
Smi* GetState() const { return state_; }
void SetState(Smi* state) { state_ = state; }
void SetContinuation(intptr_t pc) { continuation_ = pc; }
#ifdef DEBUG
Code::Kind GetKind() const { return kind_; }
void SetKind(Code::Kind kind) { kind_ = kind; }
#endif
// Get the incoming arguments count.
int ComputeParametersCount();
// Get a parameter value for an unoptimized frame.
Object* GetParameter(Deoptimizer* deoptimizer, int index);
// Get the expression stack height for a unoptimized frame.
unsigned GetExpressionCount(Deoptimizer* deoptimizer);
// Get the expression stack value for an unoptimized frame.
Object* GetExpression(Deoptimizer* deoptimizer, int index);
static int registers_offset() {
return OFFSET_OF(FrameDescription, registers_);
}
static int double_registers_offset() {
return OFFSET_OF(FrameDescription, double_registers_);
}
static int frame_size_offset() {
return OFFSET_OF(FrameDescription, frame_size_);
}
static int pc_offset() {
return OFFSET_OF(FrameDescription, pc_);
}
static int state_offset() {
return OFFSET_OF(FrameDescription, state_);
}
static int continuation_offset() {
return OFFSET_OF(FrameDescription, continuation_);
}
static int frame_content_offset() {
return OFFSET_OF(FrameDescription, frame_content_);
}
private:
static const uint32_t kZapUint32 = 0xbeeddead;
// Frame_size_ must hold a uint32_t value. It is only a uintptr_t to
// keep the variable-size array frame_content_ of type intptr_t at
// the end of the structure aligned.
uintptr_t frame_size_; // Number of bytes.
JSFunction* function_;
intptr_t registers_[Register::kNumRegisters];
double double_registers_[DoubleRegister::kNumAllocatableRegisters];
intptr_t top_;
intptr_t pc_;
intptr_t fp_;
Smi* state_;
#ifdef DEBUG
Code::Kind kind_;
#endif
// Continuation is the PC where the execution continues after
// deoptimizing.
intptr_t continuation_;
// This must be at the end of the object as the object is allocated larger
// than it's definition indicate to extend this array.
intptr_t frame_content_[1];
intptr_t* GetFrameSlotPointer(unsigned offset) {
ASSERT(offset < frame_size_);
return reinterpret_cast<intptr_t*>(
reinterpret_cast<Address>(this) + frame_content_offset() + offset);
}
};
class TranslationBuffer BASE_EMBEDDED {
public:
TranslationBuffer() : contents_(256) { }
int CurrentIndex() const { return contents_.length(); }
void Add(int32_t value);
Handle<ByteArray> CreateByteArray();
private:
ZoneList<uint8_t> contents_;
};
class TranslationIterator BASE_EMBEDDED {
public:
TranslationIterator(ByteArray* buffer, int index)
: buffer_(buffer), index_(index) {
ASSERT(index >= 0 && index < buffer->length());
}
int32_t Next();
bool HasNext() const { return index_ < buffer_->length(); }
void Skip(int n) {
for (int i = 0; i < n; i++) Next();
}
private:
ByteArray* buffer_;
int index_;
};
class Translation BASE_EMBEDDED {
public:
enum Opcode {
BEGIN,
FRAME,
REGISTER,
INT32_REGISTER,
DOUBLE_REGISTER,
STACK_SLOT,
INT32_STACK_SLOT,
DOUBLE_STACK_SLOT,
LITERAL,
ARGUMENTS_OBJECT,
// A prefix indicating that the next command is a duplicate of the one
// that follows it.
DUPLICATE
};
Translation(TranslationBuffer* buffer, int frame_count)
: buffer_(buffer),
index_(buffer->CurrentIndex()) {
buffer_->Add(BEGIN);
buffer_->Add(frame_count);
}
int index() const { return index_; }
// Commands.
void BeginFrame(int node_id, int literal_id, unsigned height);
void StoreRegister(Register reg);
void StoreInt32Register(Register reg);
void StoreDoubleRegister(DoubleRegister reg);
void StoreStackSlot(int index);
void StoreInt32StackSlot(int index);
void StoreDoubleStackSlot(int index);
void StoreLiteral(int literal_id);
void StoreArgumentsObject();
void MarkDuplicate();
static int NumberOfOperandsFor(Opcode opcode);
#if defined(OBJECT_PRINT) || defined(ENABLE_DISASSEMBLER)
static const char* StringFor(Opcode opcode);
#endif
private:
TranslationBuffer* buffer_;
int index_;
};
// Linked list holding deoptimizing code objects. The deoptimizing code objects
// are kept as weak handles until they are no longer activated on the stack.
class DeoptimizingCodeListNode : public Malloced {
public:
explicit DeoptimizingCodeListNode(Code* code);
~DeoptimizingCodeListNode();
DeoptimizingCodeListNode* next() const { return next_; }
void set_next(DeoptimizingCodeListNode* next) { next_ = next; }
Handle<Code> code() const { return code_; }
private:
// Global (weak) handle to the deoptimizing code object.
Handle<Code> code_;
// Next pointer for linked list.
DeoptimizingCodeListNode* next_;
};
class SlotRef BASE_EMBEDDED {
public:
enum SlotRepresentation {
UNKNOWN,
TAGGED,
INT32,
DOUBLE,
LITERAL
};
SlotRef()
: addr_(NULL), representation_(UNKNOWN) { }
SlotRef(Address addr, SlotRepresentation representation)
: addr_(addr), representation_(representation) { }
explicit SlotRef(Object* literal)
: literal_(literal), representation_(LITERAL) { }
Handle<Object> GetValue() {
switch (representation_) {
case TAGGED:
return Handle<Object>(Memory::Object_at(addr_));
case INT32: {
int value = Memory::int32_at(addr_);
if (Smi::IsValid(value)) {
return Handle<Object>(Smi::FromInt(value));
} else {
return Isolate::Current()->factory()->NewNumberFromInt(value);
}
}
case DOUBLE: {
double value = Memory::double_at(addr_);
return Isolate::Current()->factory()->NewNumber(value);
}
case LITERAL:
return literal_;
default:
UNREACHABLE();
return Handle<Object>::null();
}
}
static void ComputeSlotMappingForArguments(JavaScriptFrame* frame,
int inlined_frame_index,
Vector<SlotRef>* args_slots);
private:
Address addr_;
Handle<Object> literal_;
SlotRepresentation representation_;
static Address SlotAddress(JavaScriptFrame* frame, int slot_index) {
if (slot_index >= 0) {
const int offset = JavaScriptFrameConstants::kLocal0Offset;
return frame->fp() + offset - (slot_index * kPointerSize);
} else {
const int offset = JavaScriptFrameConstants::kLastParameterOffset;
return frame->fp() + offset - ((slot_index + 1) * kPointerSize);
}
}
static SlotRef ComputeSlotForNextArgument(TranslationIterator* iterator,
DeoptimizationInputData* data,
JavaScriptFrame* frame);
};
#ifdef ENABLE_DEBUGGER_SUPPORT
// Class used to represent an unoptimized frame when the debugger
// needs to inspect a frame that is part of an optimized frame. The
// internally used FrameDescription objects are not GC safe so for use
// by the debugger frame information is copied to an object of this type.
class DeoptimizedFrameInfo : public Malloced {
public:
DeoptimizedFrameInfo(Deoptimizer* deoptimizer, int frame_index);
virtual ~DeoptimizedFrameInfo();
// GC support.
void Iterate(ObjectVisitor* v);
// Return the number of incoming arguments.
int parameters_count() { return parameters_count_; }
// Return the height of the expression stack.
int expression_count() { return expression_count_; }
// Get the frame function.
JSFunction* GetFunction() {
return function_;
}
// Get an incoming argument.
Object* GetParameter(int index) {
ASSERT(0 <= index && index < parameters_count());
return parameters_[index];
}
// Get an expression from the expression stack.
Object* GetExpression(int index) {
ASSERT(0 <= index && index < expression_count());
return expression_stack_[index];
}
private:
// Set the frame function.
void SetFunction(JSFunction* function) {
function_ = function;
}
// Set an incoming argument.
void SetParameter(int index, Object* obj) {
ASSERT(0 <= index && index < parameters_count());
parameters_[index] = obj;
}
// Set an expression on the expression stack.
void SetExpression(int index, Object* obj) {
ASSERT(0 <= index && index < expression_count());
expression_stack_[index] = obj;
}
JSFunction* function_;
int parameters_count_;
int expression_count_;
Object** parameters_;
Object** expression_stack_;
friend class Deoptimizer;
};
#endif
} } // namespace v8::internal
#endif // V8_DEOPTIMIZER_H_