// 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_H_
#define V8_FULL_CODEGEN_H_
#include "src/v8.h"
#include "src/allocation.h"
#include "src/assert-scope.h"
#include "src/ast.h"
#include "src/code-stubs.h"
#include "src/codegen.h"
#include "src/compiler.h"
#include "src/data-flow.h"
#include "src/globals.h"
#include "src/objects.h"
namespace v8 {
namespace internal {
// Forward declarations.
class JumpPatchSite;
// AST node visitor which can tell whether a given statement will be breakable
// when the code is compiled by the full compiler in the debugger. This means
// that there will be an IC (load/store/call) in the code generated for the
// debugger to piggybag on.
class BreakableStatementChecker: public AstVisitor {
public:
explicit BreakableStatementChecker(Zone* zone) : is_breakable_(false) {
InitializeAstVisitor(zone);
}
void Check(Statement* stmt);
void Check(Expression* stmt);
bool is_breakable() { return is_breakable_; }
private:
// AST node visit functions.
#define DECLARE_VISIT(type) virtual void Visit##type(type* node);
AST_NODE_LIST(DECLARE_VISIT)
#undef DECLARE_VISIT
bool is_breakable_;
DEFINE_AST_VISITOR_SUBCLASS_MEMBERS();
DISALLOW_COPY_AND_ASSIGN(BreakableStatementChecker);
};
// -----------------------------------------------------------------------------
// Full code generator.
class FullCodeGenerator: public AstVisitor {
public:
enum State {
NO_REGISTERS,
TOS_REG
};
FullCodeGenerator(MacroAssembler* masm, CompilationInfo* info)
: masm_(masm),
info_(info),
scope_(info->scope()),
nesting_stack_(NULL),
loop_depth_(0),
globals_(NULL),
context_(NULL),
bailout_entries_(info->HasDeoptimizationSupport()
? info->function()->ast_node_count() : 0,
info->zone()),
back_edges_(2, info->zone()),
ic_total_count_(0) {
DCHECK(!info->IsStub());
Initialize();
}
void Initialize();
static bool MakeCode(CompilationInfo* info);
// Encode state and pc-offset as a BitField<type, start, size>.
// Only use 30 bits because we encode the result as a smi.
class StateField : public BitField<State, 0, 1> { };
class PcField : public BitField<unsigned, 1, 30-1> { };
static const char* State2String(State state) {
switch (state) {
case NO_REGISTERS: return "NO_REGISTERS";
case TOS_REG: return "TOS_REG";
}
UNREACHABLE();
return NULL;
}
static const int kMaxBackEdgeWeight = 127;
// Platform-specific code size multiplier.
#if V8_TARGET_ARCH_IA32 || V8_TARGET_ARCH_X87
static const int kCodeSizeMultiplier = 105;
static const int kBootCodeSizeMultiplier = 100;
#elif V8_TARGET_ARCH_X64
static const int kCodeSizeMultiplier = 170;
static const int kBootCodeSizeMultiplier = 140;
#elif V8_TARGET_ARCH_ARM
static const int kCodeSizeMultiplier = 149;
static const int kBootCodeSizeMultiplier = 110;
#elif V8_TARGET_ARCH_ARM64
// TODO(all): Copied ARM value. Check this is sensible for ARM64.
static const int kCodeSizeMultiplier = 149;
static const int kBootCodeSizeMultiplier = 110;
#elif V8_TARGET_ARCH_MIPS
static const int kCodeSizeMultiplier = 149;
static const int kBootCodeSizeMultiplier = 120;
#elif V8_TARGET_ARCH_MIPS64
static const int kCodeSizeMultiplier = 149;
static const int kBootCodeSizeMultiplier = 120;
#else
#error Unsupported target architecture.
#endif
private:
class Breakable;
class Iteration;
class TestContext;
class NestedStatement BASE_EMBEDDED {
public:
explicit NestedStatement(FullCodeGenerator* codegen) : codegen_(codegen) {
// 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 NULL; }
virtual Iteration* AsIteration() { return NULL; }
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
// *stack_depth the amount to drop the stack and 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* stack_depth, int* context_length) {
return previous_;
}
protected:
MacroAssembler* masm() { return codegen_->masm(); }
FullCodeGenerator* codegen_;
NestedStatement* previous_;
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) {
}
virtual ~Breakable() {}
virtual Breakable* AsBreakable() { return this; }
virtual bool IsBreakTarget(Statement* target) {
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) {
}
virtual ~Iteration() {}
virtual Iteration* AsIteration() { return this; }
virtual bool IsContinueTarget(Statement* target) {
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) {
}
virtual ~NestedBlock() {}
virtual NestedStatement* Exit(int* stack_depth, int* context_length) {
if (statement()->AsBlock()->scope() != NULL) {
++(*context_length);
}
return previous_;
}
};
// The try block of a try/catch statement.
class TryCatch : public NestedStatement {
public:
explicit TryCatch(FullCodeGenerator* codegen) : NestedStatement(codegen) {
}
virtual ~TryCatch() {}
virtual NestedStatement* Exit(int* stack_depth, int* context_length);
};
// The try block of a try/finally statement.
class TryFinally : public NestedStatement {
public:
TryFinally(FullCodeGenerator* codegen, Label* finally_entry)
: NestedStatement(codegen), finally_entry_(finally_entry) {
}
virtual ~TryFinally() {}
virtual NestedStatement* Exit(int* stack_depth, int* context_length);
private:
Label* finally_entry_;
};
// The finally block of a try/finally statement.
class Finally : public NestedStatement {
public:
static const int kElementCount = 5;
explicit Finally(FullCodeGenerator* codegen) : NestedStatement(codegen) { }
virtual ~Finally() {}
virtual NestedStatement* Exit(int* stack_depth, int* context_length) {
*stack_depth += kElementCount;
return previous_;
}
};
// The body of a for/in loop.
class ForIn : public Iteration {
public:
static const int kElementCount = 5;
ForIn(FullCodeGenerator* codegen, ForInStatement* statement)
: Iteration(codegen, statement) {
}
virtual ~ForIn() {}
virtual NestedStatement* Exit(int* stack_depth, int* context_length) {
*stack_depth += kElementCount;
return previous_;
}
};
// The body of a with or catch.
class WithOrCatch : public NestedStatement {
public:
explicit WithOrCatch(FullCodeGenerator* codegen)
: NestedStatement(codegen) {
}
virtual ~WithOrCatch() {}
virtual NestedStatement* Exit(int* stack_depth, int* context_length) {
++(*context_length);
return previous_;
}
};
// Type of a member function that generates inline code for a native function.
typedef void (FullCodeGenerator::*InlineFunctionGenerator)(CallRuntime* expr);
static const InlineFunctionGenerator kInlineFunctionGenerators[];
// 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);
#else // All non-mips arch.
void Split(Condition cc,
Label* if_true,
Label* if_false,
Label* fall_through);
#endif // V8_TARGET_ARCH_MIPS
// 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) {
EffectContext context(this);
Visit(expr);
PrepareForBailout(expr, NO_REGISTERS);
}
void VisitForAccumulatorValue(Expression* expr) {
AccumulatorValueContext context(this);
Visit(expr);
PrepareForBailout(expr, TOS_REG);
}
void VisitForStackValue(Expression* expr) {
StackValueContext context(this);
Visit(expr);
PrepareForBailout(expr, NO_REGISTERS);
}
void VisitForControl(Expression* expr,
Label* if_true,
Label* if_false,
Label* fall_through) {
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(ZoneList<Declaration*>* declarations);
void DeclareModules(Handle<FixedArray> descriptions);
void DeclareGlobals(Handle<FixedArray> pairs);
int DeclareGlobalsFlags();
// Generate code to allocate all (including nested) modules and contexts.
// Because of recursive linking and the presence of module alias declarations,
// this has to be a separate pass _before_ populating or executing any module.
void AllocateModules(ZoneList<Declaration*>* declarations);
// 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, State state);
void PrepareForBailoutForId(BailoutId id, State state);
// Feedback slot support. The feedback vector will be cleared during gc and
// collected by the type-feedback oracle.
Handle<FixedArray> FeedbackVector() {
return info_->feedback_vector();
}
void EnsureSlotContainsAllocationSite(int 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.
void EmitUnwindBeforeReturn();
// Platform-specific return sequence
void EmitReturnSequence();
// Platform-specific code sequences for calls
void EmitCall(Call* expr, CallICState::CallType = CallICState::FUNCTION);
void EmitCallWithLoadIC(Call* expr);
void EmitSuperCallWithLoadIC(Call* expr);
void EmitKeyedCallWithLoadIC(Call* expr, Expression* key);
// Platform-specific code for inline runtime calls.
InlineFunctionGenerator FindInlineFunctionGenerator(Runtime::FunctionId id);
void EmitInlineRuntimeCall(CallRuntime* expr);
#define EMIT_INLINE_RUNTIME_CALL(name, x, y) \
void Emit##name(CallRuntime* expr);
INLINE_FUNCTION_LIST(EMIT_INLINE_RUNTIME_CALL)
#undef EMIT_INLINE_RUNTIME_CALL
// Platform-specific code for resuming generators.
void EmitGeneratorResume(Expression *generator,
Expression *value,
JSGeneratorObject::ResumeMode resume_mode);
// Platform-specific code for loading variables.
void EmitLoadGlobalCheckExtensions(VariableProxy* proxy,
TypeofState typeof_state,
Label* slow);
MemOperand ContextSlotOperandCheckExtensions(Variable* var, Label* slow);
void EmitDynamicLookupFastCase(VariableProxy* proxy,
TypeofState typeof_state,
Label* slow,
Label* done);
void EmitVariableLoad(VariableProxy* proxy);
void EmitAccessor(Expression* expression);
// Expects the arguments and the function already pushed.
void EmitResolvePossiblyDirectEval(int arg_count);
// Platform-specific support for allocating a new closure based on
// the given function info.
void EmitNewClosure(Handle<SharedFunctionInfo> info, bool pretenure);
// Platform-specific support for compiling assignments.
// Load a value from a named property.
// The receiver is left on the stack by the IC.
void EmitNamedPropertyLoad(Property* expr);
void EmitNamedSuperPropertyLoad(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,
OverwriteMode mode);
// Helper functions for generating inlined smi code for certain
// binary operations.
void EmitInlineSmiBinaryOp(BinaryOperation* expr,
Token::Value op,
OverwriteMode mode,
Expression* left,
Expression* right);
// Assign to the given expression as if via '='. The right-hand-side value
// is expected in the accumulator.
void EmitAssignment(Expression* expr);
// Complete a variable assignment. The right-hand-side value is expected
// in the accumulator.
void EmitVariableAssignment(Variable* var,
Token::Value op);
// 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);
void EmitLoadHomeObject(SuperReference* expr);
void CallIC(Handle<Code> code,
TypeFeedbackId id = TypeFeedbackId::None());
void CallLoadIC(ContextualMode mode,
TypeFeedbackId id = TypeFeedbackId::None());
void CallStoreIC(TypeFeedbackId id = TypeFeedbackId::None());
void SetFunctionPosition(FunctionLiteral* fun);
void SetReturnPosition(FunctionLiteral* fun);
void SetStatementPosition(Statement* stmt);
void SetExpressionPosition(Expression* expr);
void SetSourcePosition(int pos);
// Non-local control flow support.
void EnterFinallyBlock();
void ExitFinallyBlock();
// 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() { return masm_; }
class ExpressionContext;
const ExpressionContext* context() { return context_; }
void set_new_context(const ExpressionContext* context) { context_ = context; }
Handle<Script> script() { return info_->script(); }
bool is_eval() { return info_->is_eval(); }
bool is_native() { return info_->is_native(); }
StrictMode strict_mode() { return function()->strict_mode(); }
FunctionLiteral* function() { return info_->function(); }
Scope* scope() { return scope_; }
static Register result_register();
static Register context_register();
// 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) virtual 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);
Handle<FixedArray> handler_table() { return handler_table_; }
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) { }
virtual void Plug(bool flag) const;
virtual void Plug(Register reg) const;
virtual void Plug(Label* materialize_true, Label* materialize_false) const;
virtual void Plug(Variable* var) const;
virtual void Plug(Handle<Object> lit) const;
virtual void Plug(Heap::RootListIndex) const;
virtual void PlugTOS() const;
virtual void DropAndPlug(int count, Register reg) const;
virtual void PrepareTest(Label* materialize_true,
Label* materialize_false,
Label** if_true,
Label** if_false,
Label** fall_through) const;
virtual bool IsAccumulatorValue() const { return true; }
};
class StackValueContext : public ExpressionContext {
public:
explicit StackValueContext(FullCodeGenerator* codegen)
: ExpressionContext(codegen) { }
virtual void Plug(bool flag) const;
virtual void Plug(Register reg) const;
virtual void Plug(Label* materialize_true, Label* materialize_false) const;
virtual void Plug(Variable* var) const;
virtual void Plug(Handle<Object> lit) const;
virtual void Plug(Heap::RootListIndex) const;
virtual void PlugTOS() const;
virtual void DropAndPlug(int count, Register reg) const;
virtual void PrepareTest(Label* materialize_true,
Label* materialize_false,
Label** if_true,
Label** if_false,
Label** fall_through) const;
virtual bool IsStackValue() const { 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_; }
virtual void Plug(bool flag) const;
virtual void Plug(Register reg) const;
virtual void Plug(Label* materialize_true, Label* materialize_false) const;
virtual void Plug(Variable* var) const;
virtual void Plug(Handle<Object> lit) const;
virtual void Plug(Heap::RootListIndex) const;
virtual void PlugTOS() const;
virtual void DropAndPlug(int count, Register reg) const;
virtual void PrepareTest(Label* materialize_true,
Label* materialize_false,
Label** if_true,
Label** if_false,
Label** fall_through) const;
virtual bool IsTest() const { 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) { }
virtual void Plug(bool flag) const;
virtual void Plug(Register reg) const;
virtual void Plug(Label* materialize_true, Label* materialize_false) const;
virtual void Plug(Variable* var) const;
virtual void Plug(Handle<Object> lit) const;
virtual void Plug(Heap::RootListIndex) const;
virtual void PlugTOS() const;
virtual void DropAndPlug(int count, Register reg) const;
virtual void PrepareTest(Label* materialize_true,
Label* materialize_false,
Label** if_true,
Label** if_false,
Label** fall_through) const;
virtual bool IsEffect() const { return true; }
};
MacroAssembler* masm_;
CompilationInfo* info_;
Scope* scope_;
Label return_label_;
NestedStatement* nesting_stack_;
int loop_depth_;
ZoneList<Handle<Object> >* globals_;
Handle<FixedArray> modules_;
int module_index_;
const ExpressionContext* context_;
ZoneList<BailoutEntry> bailout_entries_;
ZoneList<BackEdgeEntry> back_edges_;
int ic_total_count_;
Handle<FixedArray> handler_table_;
Handle<Cell> profiling_counter_;
bool generate_debug_code_;
friend class NestedStatement;
DEFINE_AST_VISITOR_SUBCLASS_MEMBERS();
DISALLOW_COPY_AND_ASSIGN(FullCodeGenerator);
};
// A map from property names to getter/setter pairs allocated in the zone.
class AccessorTable: public TemplateHashMap<Literal,
ObjectLiteral::Accessors,
ZoneAllocationPolicy> {
public:
explicit AccessorTable(Zone* zone) :
TemplateHashMap<Literal, ObjectLiteral::Accessors,
ZoneAllocationPolicy>(Literal::Match,
ZoneAllocationPolicy(zone)),
zone_(zone) { }
Iterator lookup(Literal* literal) {
Iterator it = find(literal, true, ZoneAllocationPolicy(zone_));
if (it->second == NULL) it->second = new(zone_) ObjectLiteral::Accessors();
return it;
}
private:
Zone* zone_;
};
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,
OSR_AFTER_STACK_CHECK
};
// 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);
// Change a back edge patched for on-stack replacement to perform a
// stack check first.
static void AddStackCheck(Handle<Code> code, uint32_t pc_offset);
// Revert the patch by AddStackCheck.
static void RemoveStackCheck(Handle<Code> code, uint32_t pc_offset);
// 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 v8::internal
#endif // V8_FULL_CODEGEN_H_