// Copyright 2006-2008 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_CODEGEN_IA32_H_
#define V8_CODEGEN_IA32_H_
#include "scopes.h"
namespace v8 { namespace internal {
// Forward declarations
class DeferredCode;
// Mode to overwrite BinaryExpression values.
enum OverwriteMode { NO_OVERWRITE, OVERWRITE_LEFT, OVERWRITE_RIGHT };
enum InitState { CONST_INIT, NOT_CONST_INIT };
enum TypeofState { INSIDE_TYPEOF, NOT_INSIDE_TYPEOF };
// -------------------------------------------------------------------------
// Virtual frame
class VirtualFrame BASE_EMBEDDED {
public:
explicit VirtualFrame(CodeGenerator* cgen);
void Enter();
void Exit();
void AllocateLocals();
Operand Top() const { return Operand(esp, 0); }
Operand Element(int index) const {
return Operand(esp, index * kPointerSize);
}
Operand Local(int index) const {
ASSERT(0 <= index && index < frame_local_count_);
return Operand(ebp, kLocal0Offset - index * kPointerSize);
}
Operand Function() const { return Operand(ebp, kFunctionOffset); }
Operand Context() const { return Operand(ebp, kContextOffset); }
Operand Parameter(int index) const {
ASSERT(-1 <= index && index < parameter_count_);
return Operand(ebp, (1 + parameter_count_ - index) * kPointerSize);
}
Operand Receiver() const { return Parameter(-1); }
inline void Drop(int count);
inline void Pop();
inline void Pop(Register reg);
inline void Pop(Operand operand);
inline void Push(Register reg);
inline void Push(Operand operand);
inline void Push(Immediate immediate);
private:
static const int kLocal0Offset = JavaScriptFrameConstants::kLocal0Offset;
static const int kFunctionOffset = JavaScriptFrameConstants::kFunctionOffset;
static const int kContextOffset = StandardFrameConstants::kContextOffset;
MacroAssembler* masm_;
int frame_local_count_;
int parameter_count_;
};
// -------------------------------------------------------------------------
// Reference support
// A reference is a C++ stack-allocated object that keeps an ECMA
// reference on the execution stack while in scope. For variables
// the reference is empty, indicating that it isn't necessary to
// store state on the stack for keeping track of references to those.
// For properties, we keep either one (named) or two (indexed) values
// on the execution stack to represent the reference.
class Reference BASE_EMBEDDED {
public:
// The values of the types is important, see size().
enum Type { ILLEGAL = -1, SLOT = 0, NAMED = 1, KEYED = 2 };
Reference(CodeGenerator* cgen, Expression* expression);
~Reference();
Expression* expression() const { return expression_; }
Type type() const { return type_; }
void set_type(Type value) {
ASSERT(type_ == ILLEGAL);
type_ = value;
}
// The size of the reference or -1 if the reference is illegal.
int size() const { return type_; }
bool is_illegal() const { return type_ == ILLEGAL; }
bool is_slot() const { return type_ == SLOT; }
bool is_property() const { return type_ == NAMED || type_ == KEYED; }
// Return the name. Only valid for named property references.
Handle<String> GetName();
// Generate code to push the value of the reference on top of the
// expression stack. The reference is expected to be already on top of
// the expression stack, and it is left in place with its value above it.
void GetValue(TypeofState typeof_state);
// Generate code to store the value on top of the expression stack in the
// reference. The reference is expected to be immediately below the value
// on the expression stack. The stored value is left in place (with the
// reference intact below it) to support chained assignments.
void SetValue(InitState init_state);
private:
CodeGenerator* cgen_;
Expression* expression_;
Type type_;
};
// -------------------------------------------------------------------------
// Code generation state
// The state is passed down the AST by the code generator (and back up, in
// the form of the state of the label pair). It is threaded through the
// call stack. Constructing a state implicitly pushes it on the owning code
// generator's stack of states, and destroying one implicitly pops it.
class CodeGenState BASE_EMBEDDED {
public:
// Create an initial code generator state. Destroying the initial state
// leaves the code generator with a NULL state.
explicit CodeGenState(CodeGenerator* owner);
// Create a code generator state based on a code generator's current
// state. The new state has its own access type and pair of branch
// labels, and no reference.
CodeGenState(CodeGenerator* owner,
TypeofState typeof_state,
Label* true_target,
Label* false_target);
// Destroy a code generator state and restore the owning code generator's
// previous state.
~CodeGenState();
TypeofState typeof_state() const { return typeof_state_; }
Label* true_target() const { return true_target_; }
Label* false_target() const { return false_target_; }
private:
CodeGenerator* owner_;
TypeofState typeof_state_;
Label* true_target_;
Label* false_target_;
CodeGenState* previous_;
};
// -------------------------------------------------------------------------
// CodeGenerator
class CodeGenerator: public Visitor {
public:
// Takes a function literal, generates code for it. This function should only
// be called by compiler.cc.
static Handle<Code> MakeCode(FunctionLiteral* fun,
Handle<Script> script,
bool is_eval);
static void SetFunctionInfo(Handle<JSFunction> fun,
int length,
int function_token_position,
int start_position,
int end_position,
bool is_expression,
bool is_toplevel,
Handle<Script> script);
// Accessors
MacroAssembler* masm() { return masm_; }
VirtualFrame* frame() const { return frame_; }
CodeGenState* state() { return state_; }
void set_state(CodeGenState* state) { state_ = state; }
void AddDeferred(DeferredCode* code) { deferred_.Add(code); }
private:
// Construction/Destruction
CodeGenerator(int buffer_size, Handle<Script> script, bool is_eval);
virtual ~CodeGenerator() { delete masm_; }
// Accessors
Scope* scope() const { return scope_; }
void ProcessDeferred();
bool is_eval() { return is_eval_; }
// State
bool has_cc() const { return cc_reg_ >= 0; }
TypeofState typeof_state() const { return state_->typeof_state(); }
Label* true_target() const { return state_->true_target(); }
Label* false_target() const { return state_->false_target(); }
// Node visitors.
#define DEF_VISIT(type) \
void Visit##type(type* node);
NODE_LIST(DEF_VISIT)
#undef DEF_VISIT
// Main code generation function
void GenCode(FunctionLiteral* fun);
// The following are used by class Reference.
void LoadReference(Reference* ref);
void UnloadReference(Reference* ref);
Operand ContextOperand(Register context, int index) const {
return Operand(context, Context::SlotOffset(index));
}
Operand SlotOperand(Slot* slot, Register tmp);
// Expressions
Operand GlobalObject() const {
return ContextOperand(esi, Context::GLOBAL_INDEX);
}
void LoadCondition(Expression* x,
TypeofState typeof_state,
Label* true_target,
Label* false_target,
bool force_cc);
void Load(Expression* x, TypeofState typeof_state = NOT_INSIDE_TYPEOF);
void LoadGlobal();
// Read a value from a slot and leave it on top of the expression stack.
void LoadFromSlot(Slot* slot, TypeofState typeof_state);
// Special code for typeof expressions: Unfortunately, we must
// be careful when loading the expression in 'typeof'
// expressions. We are not allowed to throw reference errors for
// non-existing properties of the global object, so we must make it
// look like an explicit property access, instead of an access
// through the context chain.
void LoadTypeofExpression(Expression* x);
void ToBoolean(Label* true_target, Label* false_target);
void GenericBinaryOperation(Token::Value op,
const OverwriteMode overwrite_mode = NO_OVERWRITE);
void Comparison(Condition cc, bool strict = false);
// Inline small integer literals. To prevent long attacker-controlled byte
// sequences, we only inline small Smi:s.
static const int kMaxSmiInlinedBits = 16;
bool IsInlineSmi(Literal* literal);
void SmiComparison(Condition cc, Handle<Object> value, bool strict = false);
void SmiOperation(Token::Value op,
Handle<Object> value,
bool reversed,
OverwriteMode overwrite_mode);
void CallWithArguments(ZoneList<Expression*>* arguments, int position);
// Control flow
void Branch(bool if_true, Label* L);
void CheckStack();
void CleanStack(int num_bytes);
bool CheckForInlineRuntimeCall(CallRuntime* node);
Handle<JSFunction> BuildBoilerplate(FunctionLiteral* node);
void ProcessDeclarations(ZoneList<Declaration*>* declarations);
Handle<Code> ComputeCallInitialize(int argc);
// Declare global variables and functions in the given array of
// name/value pairs.
void DeclareGlobals(Handle<FixedArray> pairs);
// Instantiate the function boilerplate.
void InstantiateBoilerplate(Handle<JSFunction> boilerplate);
// Support for type checks.
void GenerateIsSmi(ZoneList<Expression*>* args);
void GenerateIsNonNegativeSmi(ZoneList<Expression*>* args);
void GenerateIsArray(ZoneList<Expression*>* args);
// Support for arguments.length and arguments[?].
void GenerateArgumentsLength(ZoneList<Expression*>* args);
void GenerateArgumentsAccess(ZoneList<Expression*>* args);
// Support for accessing the value field of an object (used by Date).
void GenerateValueOf(ZoneList<Expression*>* args);
void GenerateSetValueOf(ZoneList<Expression*>* args);
// Fast support for charCodeAt(n).
void GenerateFastCharCodeAt(ZoneList<Expression*>* args);
// Fast support for object equality testing.
void GenerateObjectEquals(ZoneList<Expression*>* args);
// Methods and constants for fast case switch statement support.
//
// Only allow fast-case switch if the range of labels is at most
// this factor times the number of case labels.
// Value is derived from comparing the size of code generated by the normal
// switch code for Smi-labels to the size of a single pointer. If code
// quality increases this number should be decreased to match.
static const int kFastSwitchMaxOverheadFactor = 5;
// Minimal number of switch cases required before we allow jump-table
// optimization.
static const int kFastSwitchMinCaseCount = 5;
// The limit of the range of a fast-case switch, as a factor of the number
// of cases of the switch. Each platform should return a value that
// is optimal compared to the default code generated for a switch statement
// on that platform.
int FastCaseSwitchMaxOverheadFactor();
// The minimal number of cases in a switch before the fast-case switch
// optimization is enabled. Each platform should return a value that
// is optimal compared to the default code generated for a switch statement
// on that platform.
int FastCaseSwitchMinCaseCount();
// Allocate a jump table and create code to jump through it.
// Should call GenerateFastCaseSwitchCases to generate the code for
// all the cases at the appropriate point.
void GenerateFastCaseSwitchJumpTable(SwitchStatement* node, int min_index,
int range, Label *fail_label,
SmartPointer<Label*> &case_targets,
SmartPointer<Label>& case_labels);
// Generate the code for cases for the fast case switch.
// Called by GenerateFastCaseSwitchJumpTable.
void GenerateFastCaseSwitchCases(SwitchStatement* node,
SmartPointer<Label> &case_labels);
// Fast support for constant-Smi switches.
void GenerateFastCaseSwitchStatement(SwitchStatement *node, int min_index,
int range, int default_index);
// Fast support for constant-Smi switches. Tests whether switch statement
// permits optimization and calls GenerateFastCaseSwitch if it does.
// Returns true if the fast-case switch was generated, and false if not.
bool TryGenerateFastCaseSwitchStatement(SwitchStatement *node);
// Bottle-neck interface to call the Assembler to generate the statement
// position. This allows us to easily control whether statement positions
// should be generated or not.
void RecordStatementPosition(Node* node);
bool is_eval_; // Tells whether code is generated for eval.
Handle<Script> script_;
List<DeferredCode*> deferred_;
// Assembler
MacroAssembler* masm_; // to generate code
// Code generation state
Scope* scope_;
VirtualFrame* frame_;
Condition cc_reg_;
CodeGenState* state_;
bool is_inside_try_;
int break_stack_height_;
// Labels
Label function_return_;
friend class VirtualFrame;
friend class Reference;
DISALLOW_COPY_AND_ASSIGN(CodeGenerator);
};
} } // namespace v8::internal
#endif // V8_CODEGEN_IA32_H_