// Copyright 2012 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.
#ifndef V8_FULL_CODEGEN_FULL_CODEGEN_H_
#define V8_FULL_CODEGEN_FULL_CODEGEN_H_
#include "src/allocation.h"
#include "src/assert-scope.h"
#include "src/ast/ast.h"
#include "src/ast/scopes.h"
#include "src/bit-vector.h"
#include "src/code-factory.h"
#include "src/code-stubs.h"
#include "src/codegen.h"
#include "src/deoptimizer.h"
#include "src/globals.h"
#include "src/objects.h"
#include "src/source-position-table.h"
namespace v8 {
namespace internal {
// Forward declarations.
class CompilationInfo;
class CompilationJob;
class JumpPatchSite;
class Scope;
// -----------------------------------------------------------------------------
// Full code generator.
class FullCodeGenerator final : public AstVisitor<FullCodeGenerator> {
public:
FullCodeGenerator(MacroAssembler* masm, CompilationInfo* info,
uintptr_t stack_limit);
void Initialize(uintptr_t stack_limit);
static CompilationJob* NewCompilationJob(CompilationInfo* info);
static bool MakeCode(CompilationInfo* info, uintptr_t stack_limit);
static bool MakeCode(CompilationInfo* info);
// Encode bailout state and pc-offset as a BitField<type, start, size>.
// Only use 30 bits because we encode the result as a smi.
class BailoutStateField : public BitField<Deoptimizer::BailoutState, 0, 1> {};
class PcField : public BitField<unsigned, 1, 30 - 1> {};
static const int kMaxBackEdgeWeight = 127;
// Platform-specific code size multiplier.
#if V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X87
static const int kCodeSizeMultiplier = 105;
#elif V8_TARGET_ARCH_X64
static const int kCodeSizeMultiplier = 165;
#elif V8_TARGET_ARCH_ARM
static const int kCodeSizeMultiplier = 149;
#elif V8_TARGET_ARCH_ARM64
static const int kCodeSizeMultiplier = 220;
#elif V8_TARGET_ARCH_PPC64
static const int kCodeSizeMultiplier = 200;
#elif V8_TARGET_ARCH_PPC
static const int kCodeSizeMultiplier = 200;
#elif V8_TARGET_ARCH_MIPS
static const int kCodeSizeMultiplier = 149;
#elif V8_TARGET_ARCH_MIPS64
static const int kCodeSizeMultiplier = 149;
#elif V8_TARGET_ARCH_S390
// TODO(joransiu): Copied PPC value. Check this is sensible for S390.
static const int kCodeSizeMultiplier = 200;
#elif V8_TARGET_ARCH_S390X
// TODO(joransiu): Copied PPC value. Check this is sensible for S390X.
static const int kCodeSizeMultiplier = 200;
#else
#error Unsupported target architecture.
#endif
static Register result_register();
private:
typedef Deoptimizer::BailoutState BailoutState;
class Breakable;
class Iteration;
class TestContext;
class NestedStatement BASE_EMBEDDED {
public:
explicit NestedStatement(FullCodeGenerator* codegen)
: codegen_(codegen),
stack_depth_at_target_(codegen->operand_stack_depth_) {
// Link into codegen's nesting stack.
previous_ = codegen->nesting_stack_;
codegen->nesting_stack_ = this;
}
virtual ~NestedStatement() {
// Unlink from codegen's nesting stack.
DCHECK_EQ(this, codegen_->nesting_stack_);
codegen_->nesting_stack_ = previous_;
}
virtual Breakable* AsBreakable() { return nullptr; }
virtual Iteration* AsIteration() { return nullptr; }
virtual bool IsContinueTarget(Statement* target) { return false; }
virtual bool IsBreakTarget(Statement* target) { return false; }
// Notify the statement that we are exiting it via break, continue, or
// return and give it a chance to generate cleanup code. Return the
// next outer statement in the nesting stack. We accumulate in
// {*context_length} the number of context chain links to unwind as we
// traverse the nesting stack from an exit to its target.
virtual NestedStatement* Exit(int* context_length) { return previous_; }
// Determine the expected operand stack depth when this statement is being
// used as the target of an exit. The caller will drop to this depth.
int GetStackDepthAtTarget() { return stack_depth_at_target_; }
protected:
MacroAssembler* masm() { return codegen_->masm(); }
FullCodeGenerator* codegen_;
NestedStatement* previous_;
int stack_depth_at_target_;
private:
DISALLOW_COPY_AND_ASSIGN(NestedStatement);
};
// A breakable statement such as a block.
class Breakable : public NestedStatement {
public:
Breakable(FullCodeGenerator* codegen, BreakableStatement* statement)
: NestedStatement(codegen), statement_(statement) {
}
Breakable* AsBreakable() override { return this; }
bool IsBreakTarget(Statement* target) override {
return statement() == target;
}
BreakableStatement* statement() { return statement_; }
Label* break_label() { return &break_label_; }
private:
BreakableStatement* statement_;
Label break_label_;
};
// An iteration statement such as a while, for, or do loop.
class Iteration : public Breakable {
public:
Iteration(FullCodeGenerator* codegen, IterationStatement* statement)
: Breakable(codegen, statement) {
}
Iteration* AsIteration() override { return this; }
bool IsContinueTarget(Statement* target) override {
return statement() == target;
}
Label* continue_label() { return &continue_label_; }
private:
Label continue_label_;
};
// A nested block statement.
class NestedBlock : public Breakable {
public:
NestedBlock(FullCodeGenerator* codegen, Block* block)
: Breakable(codegen, block) {
}
NestedStatement* Exit(int* context_length) override {
auto block_scope = statement()->AsBlock()->scope();
if (block_scope != nullptr) {
if (block_scope->ContextLocalCount() > 0) ++(*context_length);
}
return previous_;
}
};
// A platform-specific utility to overwrite the accumulator register
// with a GC-safe value.
void ClearAccumulator();
// Determine whether or not to inline the smi case for the given
// operation.
bool ShouldInlineSmiCase(Token::Value op);
// Helper function to convert a pure value into a test context. The value
// is expected on the stack or the accumulator, depending on the platform.
// See the platform-specific implementation for details.
void DoTest(Expression* condition,
Label* if_true,
Label* if_false,
Label* fall_through);
void DoTest(const TestContext* context);
// Helper function to split control flow and avoid a branch to the
// fall-through label if it is set up.
#if V8_TARGET_ARCH_MIPS
void Split(Condition cc,
Register lhs,
const Operand& rhs,
Label* if_true,
Label* if_false,
Label* fall_through);
#elif V8_TARGET_ARCH_MIPS64
void Split(Condition cc,
Register lhs,
const Operand& rhs,
Label* if_true,
Label* if_false,
Label* fall_through);
#elif V8_TARGET_ARCH_PPC
void Split(Condition cc, Label* if_true, Label* if_false, Label* fall_through,
CRegister cr = cr7);
#else // All other arch.
void Split(Condition cc,
Label* if_true,
Label* if_false,
Label* fall_through);
#endif
// Load the value of a known (PARAMETER, LOCAL, or CONTEXT) variable into
// a register. Emits a context chain walk if if necessary (so does
// SetVar) so avoid calling both on the same variable.
void GetVar(Register destination, Variable* var);
// Assign to a known (PARAMETER, LOCAL, or CONTEXT) variable. If it's in
// the context, the write barrier will be emitted and source, scratch0,
// scratch1 will be clobbered. Emits a context chain walk if if necessary
// (so does GetVar) so avoid calling both on the same variable.
void SetVar(Variable* var,
Register source,
Register scratch0,
Register scratch1);
// An operand used to read/write a stack-allocated (PARAMETER or LOCAL)
// variable. Writing does not need the write barrier.
MemOperand StackOperand(Variable* var);
// An operand used to read/write a known (PARAMETER, LOCAL, or CONTEXT)
// variable. May emit code to traverse the context chain, loading the
// found context into the scratch register. Writing to this operand will
// need the write barrier if location is CONTEXT.
MemOperand VarOperand(Variable* var, Register scratch);
void VisitForEffect(Expression* expr) {
if (FLAG_verify_operand_stack_depth) EmitOperandStackDepthCheck();
EffectContext context(this);
Visit(expr);
PrepareForBailout(expr, BailoutState::NO_REGISTERS);
}
void VisitForAccumulatorValue(Expression* expr) {
if (FLAG_verify_operand_stack_depth) EmitOperandStackDepthCheck();
AccumulatorValueContext context(this);
Visit(expr);
PrepareForBailout(expr, BailoutState::TOS_REGISTER);
}
void VisitForStackValue(Expression* expr) {
if (FLAG_verify_operand_stack_depth) EmitOperandStackDepthCheck();
StackValueContext context(this);
Visit(expr);
PrepareForBailout(expr, BailoutState::NO_REGISTERS);
}
void VisitForControl(Expression* expr,
Label* if_true,
Label* if_false,
Label* fall_through) {
if (FLAG_verify_operand_stack_depth) EmitOperandStackDepthCheck();
TestContext context(this, expr, if_true, if_false, fall_through);
Visit(expr);
// For test contexts, we prepare for bailout before branching, not at
// the end of the entire expression. This happens as part of visiting
// the expression.
}
void VisitInDuplicateContext(Expression* expr);
void VisitDeclarations(Declaration::List* declarations);
void DeclareGlobals(Handle<FixedArray> pairs);
int DeclareGlobalsFlags();
// Push, pop or drop values onto/from the operand stack.
void PushOperand(Register reg);
void PopOperand(Register reg);
void DropOperands(int count);
// Convenience helpers for pushing onto the operand stack.
void PushOperand(MemOperand operand);
void PushOperand(Handle<Object> handle);
void PushOperand(Smi* smi);
// Convenience helpers for pushing/popping multiple operands.
void PushOperands(Register reg1, Register reg2);
void PushOperands(Register reg1, Register reg2, Register reg3);
void PushOperands(Register reg1, Register reg2, Register reg3, Register reg4);
void PopOperands(Register reg1, Register reg2);
// Convenience helper for calling a runtime function that consumes arguments
// from the operand stack (only usable for functions with known arity).
void CallRuntimeWithOperands(Runtime::FunctionId function_id);
// Static tracking of the operand stack depth.
void OperandStackDepthDecrement(int count);
void OperandStackDepthIncrement(int count);
// Generate debug code that verifies that our static tracking of the operand
// stack depth is in sync with the actual operand stack during runtime.
void EmitOperandStackDepthCheck();
// Generate code to create an iterator result object. The "value" property is
// set to a value popped from the stack, and "done" is set according to the
// argument. The result object is left in the result register.
void EmitCreateIteratorResult(bool done);
// Try to perform a comparison as a fast inlined literal compare if
// the operands allow it. Returns true if the compare operations
// has been matched and all code generated; false otherwise.
bool TryLiteralCompare(CompareOperation* compare);
// Platform-specific code for comparing the type of a value with
// a given literal string.
void EmitLiteralCompareTypeof(Expression* expr,
Expression* sub_expr,
Handle<String> check);
// Platform-specific code for equality comparison with a nil-like value.
void EmitLiteralCompareNil(CompareOperation* expr,
Expression* sub_expr,
NilValue nil);
// Bailout support.
void PrepareForBailout(Expression* node, Deoptimizer::BailoutState state);
void PrepareForBailoutForId(BailoutId id, Deoptimizer::BailoutState state);
// Returns an int32 for the index into the FixedArray that backs the feedback
// vector
int32_t IntFromSlot(FeedbackSlot slot) const {
return FeedbackVector::GetIndex(slot);
}
// Returns a smi for the index into the FixedArray that backs the feedback
// vector
Smi* SmiFromSlot(FeedbackSlot slot) const {
return Smi::FromInt(IntFromSlot(slot));
}
// Record a call's return site offset, used to rebuild the frame if the
// called function was inlined at the site.
void RecordJSReturnSite(Call* call);
// Prepare for bailout before a test (or compare) and branch. If
// should_normalize, then the following comparison will not handle the
// canonical JS true value so we will insert a (dead) test against true at
// the actual bailout target from the optimized code. If not
// should_normalize, the true and false labels are ignored.
void PrepareForBailoutBeforeSplit(Expression* expr,
bool should_normalize,
Label* if_true,
Label* if_false);
// If enabled, emit debug code for checking that the current context is
// neither a with nor a catch context.
void EmitDebugCheckDeclarationContext(Variable* variable);
// This is meant to be called at loop back edges, |back_edge_target| is
// the jump target of the back edge and is used to approximate the amount
// of code inside the loop.
void EmitBackEdgeBookkeeping(IterationStatement* stmt,
Label* back_edge_target);
// Record the OSR AST id corresponding to a back edge in the code.
void RecordBackEdge(BailoutId osr_ast_id);
// Emit a table of back edge ids, pcs and loop depths into the code stream.
// Return the offset of the start of the table.
unsigned EmitBackEdgeTable();
void EmitProfilingCounterDecrement(int delta);
void EmitProfilingCounterReset();
// Emit code to pop values from the stack associated with nested statements
// like try/catch, try/finally, etc, running the finallies and unwinding the
// handlers as needed. Also emits the return sequence if necessary (i.e.,
// if the return is not delayed by a finally block).
void EmitUnwindAndReturn();
// Platform-specific return sequence
void EmitReturnSequence();
void EmitProfilingCounterHandlingForReturnSequence(bool is_tail_call);
// Platform-specific code sequences for calls
void EmitCall(Call* expr, ConvertReceiverMode = ConvertReceiverMode::kAny);
void EmitCallWithLoadIC(Call* expr);
void EmitKeyedCallWithLoadIC(Call* expr, Expression* key);
#define FOR_EACH_FULL_CODE_INTRINSIC(F) \
F(IsSmi) \
F(IsArray) \
F(IsTypedArray) \
F(IsJSProxy) \
F(Call) \
F(IsJSReceiver) \
F(GetSuperConstructor) \
F(DebugBreakInOptimizedCode) \
F(ClassOf) \
F(StringCharCodeAt) \
F(SubString) \
F(ToInteger) \
F(ToString) \
F(ToLength) \
F(ToNumber) \
F(ToObject) \
F(DebugIsActive) \
F(CreateIterResultObject)
#define GENERATOR_DECLARATION(Name) void Emit##Name(CallRuntime* call);
FOR_EACH_FULL_CODE_INTRINSIC(GENERATOR_DECLARATION)
#undef GENERATOR_DECLARATION
void EmitIntrinsicAsStubCall(CallRuntime* expr, const Callable& callable);
// Emits call to respective code stub.
void EmitHasProperty();
// Platform-specific code for restoring context from current JS frame.
void RestoreContext();
// Platform-specific code for loading variables.
void EmitGlobalVariableLoad(VariableProxy* proxy, TypeofMode typeof_mode);
void EmitVariableLoad(VariableProxy* proxy,
TypeofMode typeof_mode = NOT_INSIDE_TYPEOF);
void EmitAccessor(ObjectLiteralProperty* property);
// Platform-specific support for allocating a new closure based on
// the given function info.
void EmitNewClosure(Handle<SharedFunctionInfo> info, FeedbackSlot slot,
bool pretenure);
// Re-usable portions of CallRuntime
void EmitLoadJSRuntimeFunction(CallRuntime* expr);
void EmitCallJSRuntimeFunction(CallRuntime* expr);
// Load a value from a named property.
// The receiver is left on the stack by the IC.
void EmitNamedPropertyLoad(Property* expr);
// Load a value from a keyed property.
// The receiver and the key is left on the stack by the IC.
void EmitKeyedPropertyLoad(Property* expr);
// Apply the compound assignment operator. Expects the left operand on top
// of the stack and the right one in the accumulator.
void EmitBinaryOp(BinaryOperation* expr, Token::Value op);
// Helper functions for generating inlined smi code for certain
// binary operations.
void EmitInlineSmiBinaryOp(BinaryOperation* expr,
Token::Value op,
Expression* left,
Expression* right);
// Assign to the given expression as if via '='. The right-hand-side value
// is expected in the accumulator. slot is only used if FLAG_vector_stores
// is true.
void EmitAssignment(Expression* expr, FeedbackSlot slot);
// Complete a variable assignment. The right-hand-side value is expected
// in the accumulator.
void EmitVariableAssignment(Variable* var, Token::Value op, FeedbackSlot slot,
HoleCheckMode hole_check_mode);
// Helper functions to EmitVariableAssignment
void EmitStoreToStackLocalOrContextSlot(Variable* var,
MemOperand location);
// Complete a named property assignment. The receiver is expected on top
// of the stack and the right-hand-side value in the accumulator.
void EmitNamedPropertyAssignment(Assignment* expr);
// Complete a keyed property assignment. The receiver and key are
// expected on top of the stack and the right-hand-side value in the
// accumulator.
void EmitKeyedPropertyAssignment(Assignment* expr);
static bool NeedsHomeObject(Expression* expr) {
return FunctionLiteral::NeedsHomeObject(expr);
}
// Adds the [[HomeObject]] to |initializer| if it is a FunctionLiteral.
// The value of the initializer is expected to be at the top of the stack.
// |offset| is the offset in the stack where the home object can be found.
void EmitSetHomeObject(Expression* initializer, int offset,
FeedbackSlot slot);
void EmitSetHomeObjectAccumulator(Expression* initializer, int offset,
FeedbackSlot slot);
// Platform-specific code for loading a slot to a register.
void EmitLoadSlot(Register destination, FeedbackSlot slot);
// Platform-specific code for pushing a slot to the stack.
void EmitPushSlot(FeedbackSlot slot);
void CallIC(Handle<Code> code,
TypeFeedbackId id = TypeFeedbackId::None());
void CallLoadIC(FeedbackSlot slot, Handle<Object> name);
void CallStoreIC(FeedbackSlot slot, Handle<Object> name,
bool store_own_property = false);
void CallKeyedStoreIC(FeedbackSlot slot);
void SetFunctionPosition(FunctionLiteral* fun);
void SetReturnPosition(FunctionLiteral* fun);
enum InsertBreak { INSERT_BREAK, SKIP_BREAK };
// During stepping we want to be able to break at each statement, but not at
// every (sub-)expression. That is why by default we insert breaks at every
// statement position, but not at every expression position, unless stated
// otherwise.
void SetStatementPosition(Statement* stmt,
InsertBreak insert_break = INSERT_BREAK);
void SetExpressionPosition(Expression* expr);
// Consider an expression a statement. As such, we also insert a break.
// This is used in loop headers where we want to break for each iteration.
void SetExpressionAsStatementPosition(Expression* expr);
void SetCallPosition(Expression* expr,
TailCallMode tail_call_mode = TailCallMode::kDisallow);
void SetConstructCallPosition(Expression* expr) {
// Currently call and construct calls are treated the same wrt debugging.
SetCallPosition(expr);
}
void RecordStatementPosition(int pos);
void RecordPosition(int pos);
// Local control flow support.
void EmitContinue(Statement* target);
void EmitBreak(Statement* target);
// Loop nesting counter.
int loop_depth() { return loop_depth_; }
void increment_loop_depth() { loop_depth_++; }
void decrement_loop_depth() {
DCHECK(loop_depth_ > 0);
loop_depth_--;
}
MacroAssembler* masm() const { return masm_; }
class ExpressionContext;
const ExpressionContext* context() { return context_; }
void set_new_context(const ExpressionContext* context) { context_ = context; }
Isolate* isolate() const { return isolate_; }
Zone* zone() const { return zone_; }
Handle<Script> script();
LanguageMode language_mode();
bool has_simple_parameters();
FunctionLiteral* literal() const;
const FeedbackVectorSpec* feedback_vector_spec() const;
Scope* scope() { return scope_; }
static Register context_register();
// Get fields from the stack frame. Offsets are the frame pointer relative
// offsets defined in, e.g., StandardFrameConstants.
void LoadFromFrameField(int frame_offset, Register value);
// Set fields in the stack frame. Offsets are the frame pointer relative
// offsets defined in, e.g., StandardFrameConstants.
void StoreToFrameField(int frame_offset, Register value);
// Load a value from the current context. Indices are defined as an enum
// in v8::internal::Context.
void LoadContextField(Register dst, int context_index);
// Push the function argument for the runtime functions PushWithContext
// and PushCatchContext.
void PushFunctionArgumentForContextAllocation();
// AST node visit functions.
#define DECLARE_VISIT(type) void Visit##type(type* node);
AST_NODE_LIST(DECLARE_VISIT)
#undef DECLARE_VISIT
void VisitComma(BinaryOperation* expr);
void VisitLogicalExpression(BinaryOperation* expr);
void VisitArithmeticExpression(BinaryOperation* expr);
void VisitForTypeofValue(Expression* expr);
void Generate();
void PopulateDeoptimizationData(Handle<Code> code);
void PopulateTypeFeedbackInfo(Handle<Code> code);
bool MustCreateObjectLiteralWithRuntime(ObjectLiteral* expr) const;
bool MustCreateArrayLiteralWithRuntime(ArrayLiteral* expr) const;
struct BailoutEntry {
BailoutId id;
unsigned pc_and_state;
};
struct BackEdgeEntry {
BailoutId id;
unsigned pc;
uint32_t loop_depth;
};
class ExpressionContext BASE_EMBEDDED {
public:
explicit ExpressionContext(FullCodeGenerator* codegen)
: masm_(codegen->masm()), old_(codegen->context()), codegen_(codegen) {
codegen->set_new_context(this);
}
virtual ~ExpressionContext() {
codegen_->set_new_context(old_);
}
Isolate* isolate() const { return codegen_->isolate(); }
// Convert constant control flow (true or false) to the result expected for
// this expression context.
virtual void Plug(bool flag) const = 0;
// Emit code to convert a pure value (in a register, known variable
// location, as a literal, or on top of the stack) into the result
// expected according to this expression context.
virtual void Plug(Register reg) const = 0;
virtual void Plug(Variable* var) const = 0;
virtual void Plug(Handle<Object> lit) const = 0;
virtual void Plug(Heap::RootListIndex index) const = 0;
virtual void PlugTOS() const = 0;
// Emit code to convert pure control flow to a pair of unbound labels into
// the result expected according to this expression context. The
// implementation will bind both labels unless it's a TestContext, which
// won't bind them at this point.
virtual void Plug(Label* materialize_true,
Label* materialize_false) const = 0;
// Emit code to discard count elements from the top of stack, then convert
// a pure value into the result expected according to this expression
// context.
virtual void DropAndPlug(int count, Register reg) const = 0;
// Set up branch labels for a test expression. The three Label** parameters
// are output parameters.
virtual void PrepareTest(Label* materialize_true,
Label* materialize_false,
Label** if_true,
Label** if_false,
Label** fall_through) const = 0;
// Returns true if we are evaluating only for side effects (i.e. if the
// result will be discarded).
virtual bool IsEffect() const { return false; }
// Returns true if we are evaluating for the value (in accu/on stack).
virtual bool IsAccumulatorValue() const { return false; }
virtual bool IsStackValue() const { return false; }
// Returns true if we are branching on the value rather than materializing
// it. Only used for asserts.
virtual bool IsTest() const { return false; }
protected:
FullCodeGenerator* codegen() const { return codegen_; }
MacroAssembler* masm() const { return masm_; }
MacroAssembler* masm_;
private:
const ExpressionContext* old_;
FullCodeGenerator* codegen_;
};
class AccumulatorValueContext : public ExpressionContext {
public:
explicit AccumulatorValueContext(FullCodeGenerator* codegen)
: ExpressionContext(codegen) { }
void Plug(bool flag) const override;
void Plug(Register reg) const override;
void Plug(Label* materialize_true, Label* materialize_false) const override;
void Plug(Variable* var) const override;
void Plug(Handle<Object> lit) const override;
void Plug(Heap::RootListIndex) const override;
void PlugTOS() const override;
void DropAndPlug(int count, Register reg) const override;
void PrepareTest(Label* materialize_true, Label* materialize_false,
Label** if_true, Label** if_false,
Label** fall_through) const override;
bool IsAccumulatorValue() const override { return true; }
};
class StackValueContext : public ExpressionContext {
public:
explicit StackValueContext(FullCodeGenerator* codegen)
: ExpressionContext(codegen) { }
void Plug(bool flag) const override;
void Plug(Register reg) const override;
void Plug(Label* materialize_true, Label* materialize_false) const override;
void Plug(Variable* var) const override;
void Plug(Handle<Object> lit) const override;
void Plug(Heap::RootListIndex) const override;
void PlugTOS() const override;
void DropAndPlug(int count, Register reg) const override;
void PrepareTest(Label* materialize_true, Label* materialize_false,
Label** if_true, Label** if_false,
Label** fall_through) const override;
bool IsStackValue() const override { return true; }
};
class TestContext : public ExpressionContext {
public:
TestContext(FullCodeGenerator* codegen,
Expression* condition,
Label* true_label,
Label* false_label,
Label* fall_through)
: ExpressionContext(codegen),
condition_(condition),
true_label_(true_label),
false_label_(false_label),
fall_through_(fall_through) { }
static const TestContext* cast(const ExpressionContext* context) {
DCHECK(context->IsTest());
return reinterpret_cast<const TestContext*>(context);
}
Expression* condition() const { return condition_; }
Label* true_label() const { return true_label_; }
Label* false_label() const { return false_label_; }
Label* fall_through() const { return fall_through_; }
void Plug(bool flag) const override;
void Plug(Register reg) const override;
void Plug(Label* materialize_true, Label* materialize_false) const override;
void Plug(Variable* var) const override;
void Plug(Handle<Object> lit) const override;
void Plug(Heap::RootListIndex) const override;
void PlugTOS() const override;
void DropAndPlug(int count, Register reg) const override;
void PrepareTest(Label* materialize_true, Label* materialize_false,
Label** if_true, Label** if_false,
Label** fall_through) const override;
bool IsTest() const override { return true; }
private:
Expression* condition_;
Label* true_label_;
Label* false_label_;
Label* fall_through_;
};
class EffectContext : public ExpressionContext {
public:
explicit EffectContext(FullCodeGenerator* codegen)
: ExpressionContext(codegen) { }
void Plug(bool flag) const override;
void Plug(Register reg) const override;
void Plug(Label* materialize_true, Label* materialize_false) const override;
void Plug(Variable* var) const override;
void Plug(Handle<Object> lit) const override;
void Plug(Heap::RootListIndex) const override;
void PlugTOS() const override;
void DropAndPlug(int count, Register reg) const override;
void PrepareTest(Label* materialize_true, Label* materialize_false,
Label** if_true, Label** if_false,
Label** fall_through) const override;
bool IsEffect() const override { return true; }
};
class EnterBlockScopeIfNeeded {
public:
EnterBlockScopeIfNeeded(FullCodeGenerator* codegen, Scope* scope,
BailoutId entry_id, BailoutId declarations_id,
BailoutId exit_id);
~EnterBlockScopeIfNeeded();
private:
MacroAssembler* masm() const { return codegen_->masm(); }
FullCodeGenerator* codegen_;
Scope* saved_scope_;
BailoutId exit_id_;
bool needs_block_context_;
};
MacroAssembler* masm_;
CompilationInfo* info_;
Isolate* isolate_;
Zone* zone_;
Scope* scope_;
Label return_label_;
NestedStatement* nesting_stack_;
int loop_depth_;
int operand_stack_depth_;
ZoneList<Handle<Object> >* globals_;
const ExpressionContext* context_;
ZoneList<BailoutEntry> bailout_entries_;
ZoneList<BackEdgeEntry> back_edges_;
SourcePositionTableBuilder source_position_table_builder_;
int ic_total_count_;
Handle<Cell> profiling_counter_;
friend class NestedStatement;
DEFINE_AST_VISITOR_SUBCLASS_MEMBERS();
DISALLOW_COPY_AND_ASSIGN(FullCodeGenerator);
};
class BackEdgeTable {
public:
BackEdgeTable(Code* code, DisallowHeapAllocation* required) {
DCHECK(code->kind() == Code::FUNCTION);
instruction_start_ = code->instruction_start();
Address table_address = instruction_start_ + code->back_edge_table_offset();
length_ = Memory::uint32_at(table_address);
start_ = table_address + kTableLengthSize;
}
uint32_t length() { return length_; }
BailoutId ast_id(uint32_t index) {
return BailoutId(static_cast<int>(
Memory::uint32_at(entry_at(index) + kAstIdOffset)));
}
uint32_t loop_depth(uint32_t index) {
return Memory::uint32_at(entry_at(index) + kLoopDepthOffset);
}
uint32_t pc_offset(uint32_t index) {
return Memory::uint32_at(entry_at(index) + kPcOffsetOffset);
}
Address pc(uint32_t index) {
return instruction_start_ + pc_offset(index);
}
enum BackEdgeState { INTERRUPT, ON_STACK_REPLACEMENT };
// Increase allowed loop nesting level by one and patch those matching loops.
static void Patch(Isolate* isolate, Code* unoptimized_code);
// Patch the back edge to the target state, provided the correct callee.
static void PatchAt(Code* unoptimized_code,
Address pc,
BackEdgeState target_state,
Code* replacement_code);
// Change all patched back edges back to normal interrupts.
static void Revert(Isolate* isolate,
Code* unoptimized_code);
// Return the current patch state of the back edge.
static BackEdgeState GetBackEdgeState(Isolate* isolate,
Code* unoptimized_code,
Address pc_after);
#ifdef DEBUG
// Verify that all back edges of a certain loop depth are patched.
static bool Verify(Isolate* isolate, Code* unoptimized_code);
#endif // DEBUG
private:
Address entry_at(uint32_t index) {
DCHECK(index < length_);
return start_ + index * kEntrySize;
}
static const int kTableLengthSize = kIntSize;
static const int kAstIdOffset = 0 * kIntSize;
static const int kPcOffsetOffset = 1 * kIntSize;
static const int kLoopDepthOffset = 2 * kIntSize;
static const int kEntrySize = 3 * kIntSize;
Address start_;
Address instruction_start_;
uint32_t length_;
};
} // namespace internal
} // namespace v8
#endif // V8_FULL_CODEGEN_FULL_CODEGEN_H_