/*

 * Copyright (c) 1999, 2007, Oracle and/or its affiliates. All rights reserved.

 * Copyright 2008, 2009 Red Hat, Inc.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

// Items on the stack and in local variables are tracked using

// SharkValue objects.

//

// All SharkValues are one of two core types, SharkNormalValue

// and SharkAddressValue, but no code outside this file should

// ever refer to those directly.  The split is because of the

// way JSRs are handled: the typeflow pass expands them into

// multiple copies, so the return addresses pushed by jsr and

// popped by ret only exist at compile time.  Having separate

// classes for these allows us to check that our jsr handling

// is correct, via assertions.

//

// There is one more type, SharkPHIValue, which is a subclass

// of SharkNormalValue with a couple of extra methods.  Use of

// SharkPHIValue outside of this file is acceptable, so long

// as it is obtained via SharkValue::as_phi().

class SharkBuilder;

class SharkPHIValue;

class SharkValue : public ResourceObj {

 protected:

  SharkValue() {}

  // Cloning

 public:

  virtual SharkValue* clone() const = 0;

  // Casting

 public:

  virtual bool           is_phi() const;

  virtual SharkPHIValue* as_phi();

  // Comparison

 public:

  virtual bool equal_to(SharkValue* other) const = 0;

  // Type access

 public:

  virtual BasicType basic_type() const = 0;

  virtual ciType*   type()       const;

  virtual bool is_jint()    const;

  virtual bool is_jlong()   const;

  virtual bool is_jfloat()  const;

  virtual bool is_jdouble() const;

  virtual bool is_jobject() const;

  virtual bool is_jarray()  const;

  virtual bool is_address() const;

  virtual int size() const = 0;

  bool is_one_word() const {

    return size() == 1;

  }

  bool is_two_word() const {

    return size() == 2;

  }

  // Typed conversion from SharkValues

 public:

  virtual llvm::Value* jint_value()    const;

  virtual llvm::Value* jlong_value()   const;

  virtual llvm::Value* jfloat_value()  const;

  virtual llvm::Value* jdouble_value() const;

  virtual llvm::Value* jobject_value() const;

  virtual llvm::Value* jarray_value()  const;

  virtual int          address_value() const;

  // Typed conversion to SharkValues

 public:

  static SharkValue* create_jint(llvm::Value* value, bool zero_checked) {

    assert(value->getType() == SharkType::jint_type(), "should be");

    return create_generic(ciType::make(T_INT), value, zero_checked);

  }

  static SharkValue* create_jlong(llvm::Value* value, bool zero_checked) {

    assert(value->getType() == SharkType::jlong_type(), "should be");

    return create_generic(ciType::make(T_LONG), value, zero_checked);

  }

  static SharkValue* create_jfloat(llvm::Value* value) {

    assert(value->getType() == SharkType::jfloat_type(), "should be");

    return create_generic(ciType::make(T_FLOAT), value, false);

  }

  static SharkValue* create_jdouble(llvm::Value* value) {

    assert(value->getType() == SharkType::jdouble_type(), "should be");

    return create_generic(ciType::make(T_DOUBLE), value, false);

  }

  static SharkValue* create_jobject(llvm::Value* value, bool zero_checked) {

    assert(value->getType() == SharkType::oop_type(), "should be");

    return create_generic(ciType::make(T_OBJECT), value, zero_checked);

  }

  // Typed conversion from constants of various types

 public:

  static SharkValue* jint_constant(jint value) {

    return create_jint(LLVMValue::jint_constant(value), value != 0);

  }

  static SharkValue* jlong_constant(jlong value) {

    return create_jlong(LLVMValue::jlong_constant(value), value != 0);

  }

  static SharkValue* jfloat_constant(jfloat value) {

    return create_jfloat(LLVMValue::jfloat_constant(value));

  }

  static SharkValue* jdouble_constant(jdouble value) {

    return create_jdouble(LLVMValue::jdouble_constant(value));

  }

  static SharkValue* null() {

    return create_jobject(LLVMValue::null(), false);

  }

  static inline SharkValue* address_constant(int bci);

  // Type-losing conversions -- use with care!

 public:

  virtual llvm::Value* generic_value() const = 0;

  virtual llvm::Value* intptr_value(SharkBuilder* builder) const;

  static inline SharkValue* create_generic(ciType*      type,

                                           llvm::Value* value,

                                           bool         zero_checked);

  static inline SharkValue* create_phi(ciType*              type,

                                       llvm::PHINode*       phi,

                                       const SharkPHIValue* parent = NULL);

  // Phi-style stuff

 public:

  virtual void addIncoming(SharkValue* value, llvm::BasicBlock* block);

  virtual SharkValue* merge(SharkBuilder*     builder,

                            SharkValue*       other,

                            llvm::BasicBlock* other_block,

                            llvm::BasicBlock* this_block,

                            const char*       name) = 0;

  // Repeated null and divide-by-zero check removal

 public:

  virtual bool zero_checked() const;

  virtual void set_zero_checked(bool zero_checked);

};

class SharkNormalValue : public SharkValue {

  friend class SharkValue;

 protected:

  SharkNormalValue(ciType* type, llvm::Value* value, bool zero_checked)

    : _type(type), _llvm_value(value), _zero_checked(zero_checked) {}

 private:

  ciType*      _type;

  llvm::Value* _llvm_value;

  bool         _zero_checked;

 private:

  llvm::Value* llvm_value() const {

    return _llvm_value;

  }

  // Cloning

 public:

  SharkValue* clone() const;

  // Comparison

 public:

  bool equal_to(SharkValue* other) const;

  // Type access

 public:

  ciType*   type()       const;

  BasicType basic_type() const;

  int       size()       const;

 public:

  bool is_jint()    const;

  bool is_jlong()   const;

  bool is_jfloat()  const;

  bool is_jdouble() const;

  bool is_jobject() const;

  bool is_jarray()  const;

  // Typed conversions to LLVM values

 public:

  llvm::Value* jint_value()    const;

  llvm::Value* jlong_value()   const;

  llvm::Value* jfloat_value()  const;

  llvm::Value* jdouble_value() const;

  llvm::Value* jobject_value() const;

  llvm::Value* jarray_value()  const;

  // Type-losing conversions, use with care

 public:

  llvm::Value* generic_value() const;

  llvm::Value* intptr_value(SharkBuilder* builder) const;

  // Phi-style stuff

 public:

  SharkValue* merge(SharkBuilder*     builder,

                    SharkValue*       other,

                    llvm::BasicBlock* other_block,

                    llvm::BasicBlock* this_block,

                    const char*       name);

  // Repeated null and divide-by-zero check removal

 public:

  bool zero_checked() const;

  void set_zero_checked(bool zero_checked);

};

class SharkPHIValue : public SharkNormalValue {

  friend class SharkValue;

 protected:

  SharkPHIValue(ciType* type, llvm::PHINode* phi, const SharkPHIValue *parent)

    : SharkNormalValue(type, phi, parent && parent->zero_checked()),

      _parent(parent),

      _all_incomers_zero_checked(true) {}

 private:

  const SharkPHIValue* _parent;

  bool                 _all_incomers_zero_checked;

 private:

  const SharkPHIValue* parent() const {

    return _parent;

  }

  bool is_clone() const {

    return parent() != NULL;

  }

 public:

  bool all_incomers_zero_checked() const {

    if (is_clone())

      return parent()->all_incomers_zero_checked();

    return _all_incomers_zero_checked;

  }

  // Cloning

 public:

  SharkValue* clone() const;

  // Casting

 public:

  bool           is_phi() const;

  SharkPHIValue* as_phi();

  // Phi-style stuff

 public:

  void addIncoming(SharkValue *value, llvm::BasicBlock* block);

};

class SharkAddressValue : public SharkValue {

  friend class SharkValue;

 protected:

  SharkAddressValue(int bci)

    : _bci(bci) {}

 private:

  int _bci;

  // Cloning

 public:

  SharkValue* clone() const;

  // Comparison

 public:

  bool equal_to(SharkValue* other) const;

  // Type access

 public:

  BasicType basic_type() const;

  int       size()       const;

  bool      is_address() const;

  // Typed conversion from SharkValues

 public:

  int address_value() const;

  // Type-losing conversion -- use with care!

 public:

  llvm::Value* generic_value() const;

  // Phi-style stuff

 public:

  void addIncoming(SharkValue *value, llvm::BasicBlock* block);

  SharkValue* merge(SharkBuilder*     builder,

                    SharkValue*       other,

                    llvm::BasicBlock* other_block,

                    llvm::BasicBlock* this_block,

                    const char*       name);

};

// SharkValue methods that can't be declared above

inline SharkValue* SharkValue::create_generic(ciType*      type,

                                              llvm::Value* value,

                                              bool         zero_checked) {

  return new SharkNormalValue(type, value, zero_checked);

}

inline SharkValue* SharkValue::create_phi(ciType*              type,

                                          llvm::PHINode*       phi,

                                          const SharkPHIValue* parent) {

  return new SharkPHIValue(type, phi, parent);

}

inline SharkValue* SharkValue::address_constant(int bci) {

  return new SharkAddressValue(bci);

}