codegen-arm.cc.svn-base

Google浏览器V8内核代码

// 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.

#include "v8.h"

#include "bootstrapper.h"
#include "codegen-inl.h"
#include "debug.h"
#include "prettyprinter.h"
#include "scopeinfo.h"
#include "scopes.h"
#include "runtime.h"

namespace v8 { namespace internal {

class ArmCodeGenerator;


// -----------------------------------------------------------------------------
// 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:
  enum Type { ILLEGAL = -1, EMPTY = 0, NAMED = 1, KEYED = 2 };
  Reference(ArmCodeGenerator* cgen, Expression* expression);
  ~Reference();

  Expression* expression() const  { return expression_; }
  Type type() const  { return type_; }
  void set_type(Type value)  {
    ASSERT(type_ == ILLEGAL);
    type_ = value;
  }
  int size() const  { return type_; }

  bool is_illegal() const  { return type_ == ILLEGAL; }

 private:
  ArmCodeGenerator* cgen_;
  Expression* expression_;
  Type type_;
};


// -------------------------------------------------------------------------
// Code generation state

// The state is passed down the AST by the code generator.  It is passed
// implicitly (in a member variable) to the non-static code generator member
// functions, and explicitly (as an argument) to the static member functions
// and the AST node member functions.
//
// The state 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:
  enum AccessType {
    UNDEFINED,
    LOAD,
    LOAD_TYPEOF_EXPR
  };

  // Create an initial code generator state.  Destroying the initial state
  // leaves the code generator with a NULL state.
  explicit CodeGenState(ArmCodeGenerator* 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(ArmCodeGenerator* owner,
               AccessType access,
               Label* true_target,
               Label* false_target);

  // Create a code generator state based on a code generator's current
  // state.  The new state has an access type of LOAD, its own reference,
  // and inherits the pair of branch labels of the current state.
  CodeGenState(ArmCodeGenerator* owner, Reference* ref);

  // Destroy a code generator state and restore the owning code generator's
  // previous state.
  ~CodeGenState();

  AccessType access() const { return access_; }
  Reference* ref() const { return ref_; }
  Label* true_target() const { return true_target_; }
  Label* false_target() const { return false_target_; }

 private:
  ArmCodeGenerator* owner_;
  AccessType access_;
  Reference* ref_;
  Label* true_target_;
  Label* false_target_;
  CodeGenState* previous_;
};


// -----------------------------------------------------------------------------
// ArmCodeGenerator

class ArmCodeGenerator: public CodeGenerator {
 public:
  static Handle<Code> MakeCode(FunctionLiteral* fun,
                               Handle<Script> script,
                               bool is_eval);

  MacroAssembler* masm()  { return masm_; }

  CodeGenState* state() { return state_; }
  void set_state(CodeGenState* state) { state_ = state; }

 private:
  // Assembler
  MacroAssembler* masm_;  // to generate code

  // Code generation state
  Scope* scope_;
  Condition cc_reg_;
  CodeGenState* state_;
  int break_stack_height_;

  // Labels
  Label function_return_;

  // Construction/destruction
  ArmCodeGenerator(int buffer_size,
                   Handle<Script> script,
                   bool is_eval);

  virtual ~ArmCodeGenerator()  { delete masm_; }

  // Main code generation function
  void GenCode(FunctionLiteral* fun);

  // The following are used by class Reference.
  void LoadReference(Reference* ref);
  void UnloadReference(Reference* ref);

  // State
  bool has_cc() const  { return cc_reg_ != al; }
  CodeGenState::AccessType access() const  { return state_->access(); }
  Reference* ref() const  { return state_->ref(); }
  bool is_referenced() const { return state_->ref() != NULL; }
  Label* true_target() const  { return state_->true_target(); }
  Label* false_target() const  { return state_->false_target(); }


  // Expressions
  MemOperand GlobalObject() const  {
    return ContextOperand(cp, Context::GLOBAL_INDEX);
  }

  static MemOperand ContextOperand(Register context, int index) {
    return MemOperand(context, Context::SlotOffset(index));
  }

  static MemOperand ParameterOperand(Scope* scope, int index) {
    // index -2 corresponds to the activated closure, -1 corresponds
    // to the receiver
    ASSERT(-2 <= index && index < scope->num_parameters());
    int offset = (1 + scope->num_parameters() - index) * kPointerSize;
    return MemOperand(fp, offset);
  }

  MemOperand ParameterOperand(int index) const {
    return ParameterOperand(scope_, index);
  }

  MemOperand FunctionOperand() const {
    return MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset);
  }

  static MemOperand SlotOperand(MacroAssembler* masm,
                                Scope* scope,
                                Slot* slot,
                                Register tmp);

  MemOperand SlotOperand(Slot* slot, Register tmp) {
    return SlotOperand(masm_, scope_, slot, tmp);
  }

  void LoadCondition(Expression* x, CodeGenState::AccessType access,
                     Label* true_target, Label* false_target, bool force_cc);
  void Load(Expression* x,
            CodeGenState::AccessType access = CodeGenState::LOAD);
  void LoadGlobal();

  // 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);


  // References

  // Generate code to fetch the value of a reference.  The reference is
  // expected to be on top of the expression stack.  It is left in place and
  // its value is pushed on top of it.
  void GetValue(Reference* ref) {
    ASSERT(!has_cc());
    ASSERT(!ref->is_illegal());
    CodeGenState new_state(this, ref);
    Visit(ref->expression());
  }

  // Generate code to store a value in a reference.  The stored value is
  // expected on top of the expression stack, with the reference immediately
  // below it.  The expression stack is left unchanged.
  void SetValue(Reference* ref) {
    ASSERT(!has_cc());
    ASSERT(!ref->is_illegal());
    ref->expression()->GenerateStoreCode(masm_, scope_, ref, NOT_CONST_INIT);
  }

  // Generate code to store a value in a reference.  The stored value is
  // expected on top of the expression stack, with the reference immediately
  // below it.  The expression stack is left unchanged.
  void InitConst(Reference* ref) {
    ASSERT(!has_cc());
    ASSERT(!ref->is_illegal());
    ref->expression()->GenerateStoreCode(masm_, scope_, ref, CONST_INIT);
  }

  // Generate code to fetch a value from a property of a reference.  The
  // reference is expected on top of the expression stack.  It is left in
  // place and its value is pushed on top of it.
  void GetReferenceProperty(Expression* key);

  // Generate code to store a value in a property of a reference.  The
  // stored value is expected on top of the expression stack, with the
  // reference immediately below it.  The expression stack is left
  // unchanged.
  static void SetReferenceProperty(MacroAssembler* masm,
                                   Reference* ref,
                                   Expression* key);


  void ToBoolean(Label* true_target, Label* false_target);

  void GenericBinaryOperation(Token::Value op);
  void Comparison(Condition cc, bool strict = false);

  void SmiOperation(Token::Value op, Handle<Object> value, bool reversed);

  void CallWithArguments(ZoneList<Expression*>* arguments, int position);

  // Declare global variables and functions in the given array of
  // name/value pairs.
  virtual void DeclareGlobals(Handle<FixedArray> pairs);

  // Instantiate the function boilerplate.
  void InstantiateBoilerplate(Handle<JSFunction> boilerplate);

  // Control flow
  void Branch(bool if_true, Label* L);
  void CheckStack();
  void CleanStack(int num_bytes);

  // Node visitors
#define DEF_VISIT(type)                         \
  virtual void Visit##type(type* node);
  NODE_LIST(DEF_VISIT)
#undef DEF_VISIT

  void RecordStatementPosition(Node* node);

  // Activation frames
  void EnterJSFrame();
  void ExitJSFrame();

  virtual void GenerateIsSmi(ZoneList<Expression*>* args);
  virtual void GenerateIsNonNegativeSmi(ZoneList<Expression*>* args);
  virtual void GenerateIsArray(ZoneList<Expression*>* args);

  virtual void GenerateArgumentsLength(ZoneList<Expression*>* args);
  virtual void GenerateArgumentsAccess(ZoneList<Expression*>* args);

  virtual void GenerateValueOf(ZoneList<Expression*>* args);
  virtual void GenerateSetValueOf(ZoneList<Expression*>* args);

  virtual void GenerateFastCharCodeAt(ZoneList<Expression*>* args);

  virtual void GenerateObjectEquals(ZoneList<Expression*>* args);

  friend class Reference;
  friend class Property;
  friend class VariableProxy;
  friend class Slot;
};


// -------------------------------------------------------------------------
// CodeGenState implementation.

CodeGenState::CodeGenState(ArmCodeGenerator* owner)
    : owner_(owner),
      access_(UNDEFINED),
      ref_(NULL),
      true_target_(NULL),
      false_target_(NULL),
      previous_(NULL) {
  owner_->set_state(this);
}


CodeGenState::CodeGenState(ArmCodeGenerator* owner,
                           AccessType access,
                           Label* true_target,
                           Label* false_target)
    : owner_(owner),
      access_(access),
      ref_(NULL),
      true_target_(true_target),
      false_target_(false_target),
      previous_(owner->state()) {
  owner_->set_state(this);
}


CodeGenState::CodeGenState(ArmCodeGenerator* owner, Reference* ref)
    : owner_(owner),
      access_(LOAD),
      ref_(ref),
      true_target_(owner->state()->true_target_),
      false_target_(owner->state()->false_target_),
      previous_(owner->state()) {
  owner_->set_state(this);
}


CodeGenState::~CodeGenState() {
  ASSERT(owner_->state() == this);
  owner_->set_state(previous_);
}


// -----------------------------------------------------------------------------
// ArmCodeGenerator implementation

#define __  masm_->


Handle<Code> ArmCodeGenerator::MakeCode(FunctionLiteral* flit,
                                        Handle<Script> script,
                                        bool is_eval) {
#ifdef ENABLE_DISASSEMBLER
  bool print_code = FLAG_print_code && !Bootstrapper::IsActive();
#endif  // ENABLE_DISASSEMBLER

#ifdef DEBUG