/*

 * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.

 * 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.

 *

 */

class CodeEmitInfo;

class LIR_Assembler;

class LIR_OpVisitState;

// CodeStubs are little 'out-of-line' pieces of code that

// usually handle slow cases of operations. All code stubs

// are collected and code is emitted at the end of the

// nmethod.

class CodeStub: public CompilationResourceObj {

 protected:

  Label _entry;                                  // label at the stub entry point

  Label _continuation;                           // label where stub continues, if any

 public:

  CodeStub() {}

  // code generation

  void assert_no_unbound_labels()                { assert(!_entry.is_unbound() && !_continuation.is_unbound(), "unbound label"); }

  virtual void emit_code(LIR_Assembler* e) = 0;

  virtual CodeEmitInfo* info() const             { return NULL; }

  virtual bool is_exception_throw_stub() const   { return false; }

  virtual bool is_range_check_stub() const       { return false; }

  virtual bool is_divbyzero_stub() const         { return false; }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const = 0;

#endif

  // label access

  Label* entry()                                 { return &_entry; }

  Label* continuation()                          { return &_continuation; }

  // for LIR

  virtual void visit(LIR_OpVisitState* visit) {

#ifndef PRODUCT

    if (LIRTracePeephole && Verbose) {

      tty->print("no visitor for ");

      print_name(tty);

      tty->cr();

    }

#endif

  }

};

define_array(CodeStubArray, CodeStub*)

define_stack(_CodeStubList, CodeStubArray)

class CodeStubList: public _CodeStubList {

 public:

  CodeStubList(): _CodeStubList() {}

  void append(CodeStub* stub) {

    if (!contains(stub)) {

      _CodeStubList::append(stub);

    }

  }

};

class CounterOverflowStub: public CodeStub {

 private:

  CodeEmitInfo* _info;

  int           _bci;

  LIR_Opr       _method;

public:

  CounterOverflowStub(CodeEmitInfo* info, int bci, LIR_Opr method) :  _info(info), _bci(bci), _method(method) {

  }

  virtual void emit_code(LIR_Assembler* e);

  virtual void visit(LIR_OpVisitState* visitor) {

    visitor->do_slow_case(_info);

    visitor->do_input(_method);

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("CounterOverflowStub"); }

#endif // PRODUCT

};

class ConversionStub: public CodeStub {

 private:

  Bytecodes::Code _bytecode;

  LIR_Opr         _input;

  LIR_Opr         _result;

  static float float_zero;

  static double double_zero;

 public:

  ConversionStub(Bytecodes::Code bytecode, LIR_Opr input, LIR_Opr result)

    : _bytecode(bytecode), _input(input), _result(result) {

  }

  Bytecodes::Code bytecode() { return _bytecode; }

  LIR_Opr         input()    { return _input; }

  LIR_Opr         result()   { return _result; }

  virtual void emit_code(LIR_Assembler* e);

  virtual void visit(LIR_OpVisitState* visitor) {

    visitor->do_slow_case();

    visitor->do_input(_input);

    visitor->do_output(_result);

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("ConversionStub"); }

#endif // PRODUCT

};

// Throws ArrayIndexOutOfBoundsException by default but can be

// configured to throw IndexOutOfBoundsException in constructor

class RangeCheckStub: public CodeStub {

 private:

  CodeEmitInfo* _info;

  LIR_Opr       _index;

  bool          _throw_index_out_of_bounds_exception;

 public:

  RangeCheckStub(CodeEmitInfo* info, LIR_Opr index, bool throw_index_out_of_bounds_exception = false);

  virtual void emit_code(LIR_Assembler* e);

  virtual CodeEmitInfo* info() const             { return _info; }

  virtual bool is_exception_throw_stub() const   { return true; }

  virtual bool is_range_check_stub() const       { return true; }

  virtual void visit(LIR_OpVisitState* visitor) {

    visitor->do_slow_case(_info);

    visitor->do_input(_index);

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("RangeCheckStub"); }

#endif // PRODUCT

};

class DivByZeroStub: public CodeStub {

 private:

  CodeEmitInfo* _info;

  int           _offset;

 public:

  DivByZeroStub(CodeEmitInfo* info)

    : _info(info), _offset(-1) {

  }

  DivByZeroStub(int offset, CodeEmitInfo* info)

    : _info(info), _offset(offset) {

  }

  virtual void emit_code(LIR_Assembler* e);

  virtual CodeEmitInfo* info() const             { return _info; }

  virtual bool is_exception_throw_stub() const   { return true; }

  virtual bool is_divbyzero_stub() const         { return true; }

  virtual void visit(LIR_OpVisitState* visitor) {

    visitor->do_slow_case(_info);

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("DivByZeroStub"); }

#endif // PRODUCT

};

class ImplicitNullCheckStub: public CodeStub {

 private:

  CodeEmitInfo* _info;

  int           _offset;

 public:

  ImplicitNullCheckStub(int offset, CodeEmitInfo* info)

    : _offset(offset), _info(info) {

  }

  virtual void emit_code(LIR_Assembler* e);

  virtual CodeEmitInfo* info() const             { return _info; }

  virtual bool is_exception_throw_stub() const   { return true; }

  virtual void visit(LIR_OpVisitState* visitor) {

    visitor->do_slow_case(_info);

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("ImplicitNullCheckStub"); }

#endif // PRODUCT

};

class NewInstanceStub: public CodeStub {

 private:

  ciInstanceKlass* _klass;

  LIR_Opr          _klass_reg;

  LIR_Opr          _result;

  CodeEmitInfo*    _info;

  Runtime1::StubID _stub_id;

 public:

  NewInstanceStub(LIR_Opr klass_reg, LIR_Opr result, ciInstanceKlass* klass, CodeEmitInfo* info, Runtime1::StubID stub_id);

  virtual void emit_code(LIR_Assembler* e);

  virtual CodeEmitInfo* info() const             { return _info; }

  virtual void visit(LIR_OpVisitState* visitor) {

    visitor->do_slow_case(_info);

    visitor->do_input(_klass_reg);

    visitor->do_output(_result);

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("NewInstanceStub"); }

#endif // PRODUCT

};

class NewTypeArrayStub: public CodeStub {

 private:

  LIR_Opr       _klass_reg;

  LIR_Opr       _length;

  LIR_Opr       _result;

  CodeEmitInfo* _info;

 public:

  NewTypeArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info);

  virtual void emit_code(LIR_Assembler* e);

  virtual CodeEmitInfo* info() const             { return _info; }

  virtual void visit(LIR_OpVisitState* visitor) {

    visitor->do_slow_case(_info);

    visitor->do_input(_klass_reg);

    visitor->do_input(_length);

    assert(_result->is_valid(), "must be valid"); visitor->do_output(_result);

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("NewTypeArrayStub"); }

#endif // PRODUCT

};

class NewObjectArrayStub: public CodeStub {

 private:

  LIR_Opr        _klass_reg;

  LIR_Opr        _length;

  LIR_Opr        _result;

  CodeEmitInfo*  _info;

 public:

  NewObjectArrayStub(LIR_Opr klass_reg, LIR_Opr length, LIR_Opr result, CodeEmitInfo* info);

  virtual void emit_code(LIR_Assembler* e);

  virtual CodeEmitInfo* info() const             { return _info; }

  virtual void visit(LIR_OpVisitState* visitor) {

    visitor->do_slow_case(_info);

    visitor->do_input(_klass_reg);

    visitor->do_input(_length);

    assert(_result->is_valid(), "must be valid"); visitor->do_output(_result);

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("NewObjectArrayStub"); }

#endif // PRODUCT

};

class MonitorAccessStub: public CodeStub {

 protected:

  LIR_Opr _obj_reg;

  LIR_Opr _lock_reg;

 public:

  MonitorAccessStub(LIR_Opr obj_reg, LIR_Opr lock_reg) {

    _obj_reg  = obj_reg;

    _lock_reg  = lock_reg;

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("MonitorAccessStub"); }

#endif // PRODUCT

};

class MonitorEnterStub: public MonitorAccessStub {

 private:

  CodeEmitInfo* _info;

 public:

  MonitorEnterStub(LIR_Opr obj_reg, LIR_Opr lock_reg, CodeEmitInfo* info);

  virtual void emit_code(LIR_Assembler* e);

  virtual CodeEmitInfo* info() const             { return _info; }

  virtual void visit(LIR_OpVisitState* visitor) {

    visitor->do_input(_obj_reg);

    visitor->do_input(_lock_reg);

    visitor->do_slow_case(_info);

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("MonitorEnterStub"); }

#endif // PRODUCT

};

class MonitorExitStub: public MonitorAccessStub {

 private:

  bool _compute_lock;

  int  _monitor_ix;

 public:

  MonitorExitStub(LIR_Opr lock_reg, bool compute_lock, int monitor_ix)

    : MonitorAccessStub(LIR_OprFact::illegalOpr, lock_reg),

      _compute_lock(compute_lock), _monitor_ix(monitor_ix) { }

  virtual void emit_code(LIR_Assembler* e);

  virtual void visit(LIR_OpVisitState* visitor) {

    assert(_obj_reg->is_illegal(), "unused");

    if (_compute_lock) {

      visitor->do_temp(_lock_reg);

    } else {

      visitor->do_input(_lock_reg);

    }

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("MonitorExitStub"); }

#endif // PRODUCT

};

class PatchingStub: public CodeStub {

 public:

  enum PatchID {

    access_field_id,

    load_klass_id

  };

  enum constants {

    patch_info_size = 3

  };

 private:

  PatchID       _id;

  address       _pc_start;

  int           _bytes_to_copy;

  Label         _patched_code_entry;

  Label         _patch_site_entry;

  Label         _patch_site_continuation;

  Register      _obj;

  CodeEmitInfo* _info;

  int           _oop_index;  // index of the patchable oop in nmethod oop table if needed

  static int    _patch_info_offset;

  void align_patch_site(MacroAssembler* masm);

 public:

  static int patch_info_offset() { return _patch_info_offset; }

  PatchingStub(MacroAssembler* masm, PatchID id, int oop_index = -1):

      _id(id)

    , _info(NULL)

    , _oop_index(oop_index) {

    if (os::is_MP()) {

      // force alignment of patch sites on MP hardware so we

      // can guarantee atomic writes to the patch site.

      align_patch_site(masm);

    }

    _pc_start = masm->pc();

    masm->bind(_patch_site_entry);

  }

  void install(MacroAssembler* masm, LIR_PatchCode patch_code, Register obj, CodeEmitInfo* info) {

    _info = info;

    _obj = obj;

    masm->bind(_patch_site_continuation);

    _bytes_to_copy = masm->pc() - pc_start();

    if (_id == PatchingStub::access_field_id) {

      // embed a fixed offset to handle long patches which need to be offset by a word.

      // the patching code will just add the field offset field to this offset so

      // that we can refernce either the high or low word of a double word field.

      int field_offset = 0;

      switch (patch_code) {

      case lir_patch_low:         field_offset = lo_word_offset_in_bytes; break;

      case lir_patch_high:        field_offset = hi_word_offset_in_bytes; break;

      case lir_patch_normal:      field_offset = 0;                       break;

      default: ShouldNotReachHere();

      }

      NativeMovRegMem* n_move = nativeMovRegMem_at(pc_start());

      n_move->set_offset(field_offset);

    } else if (_id == load_klass_id) {

      assert(_obj != noreg, "must have register object for load_klass");

#ifdef ASSERT

      // verify that we're pointing at a NativeMovConstReg

      nativeMovConstReg_at(pc_start());

#endif

    } else {

      ShouldNotReachHere();

    }

    assert(_bytes_to_copy <= (masm->pc() - pc_start()), "not enough bytes");

  }

  address pc_start() const                       { return _pc_start; }

  PatchID id() const                             { return _id; }

  virtual void emit_code(LIR_Assembler* e);

  virtual CodeEmitInfo* info() const             { return _info; }

  virtual void visit(LIR_OpVisitState* visitor) {

    visitor->do_slow_case(_info);

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("PatchingStub"); }

#endif // PRODUCT

};

//------------------------------------------------------------------------------

// DeoptimizeStub

//

class DeoptimizeStub : public CodeStub {

private:

  CodeEmitInfo* _info;

public:

  DeoptimizeStub(CodeEmitInfo* info) : _info(new CodeEmitInfo(info)) {}

  virtual void emit_code(LIR_Assembler* e);

  virtual CodeEmitInfo* info() const           { return _info; }

  virtual bool is_exception_throw_stub() const { return true; }

  virtual void visit(LIR_OpVisitState* visitor) {

    visitor->do_slow_case(_info);

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("DeoptimizeStub"); }

#endif // PRODUCT

};

class SimpleExceptionStub: public CodeStub {

 private:

  LIR_Opr          _obj;

  Runtime1::StubID _stub;

  CodeEmitInfo*    _info;

 public:

  SimpleExceptionStub(Runtime1::StubID stub, LIR_Opr obj, CodeEmitInfo* info):

    _obj(obj), _info(info), _stub(stub) {

  }

  void set_obj(LIR_Opr obj) {

    _obj = obj;

  }

  virtual void emit_code(LIR_Assembler* e);

  virtual CodeEmitInfo* info() const             { return _info; }

  virtual bool is_exception_throw_stub() const   { return true; }

  virtual void visit(LIR_OpVisitState* visitor) {

    if (_obj->is_valid()) visitor->do_input(_obj);

    visitor->do_slow_case(_info);

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("SimpleExceptionStub"); }

#endif // PRODUCT

};

class ArrayStoreExceptionStub: public CodeStub {

 private:

  CodeEmitInfo* _info;

 public:

  ArrayStoreExceptionStub(CodeEmitInfo* info);

  virtual void emit_code(LIR_Assembler* emit);

  virtual CodeEmitInfo* info() const             { return _info; }

  virtual bool is_exception_throw_stub() const   { return true; }

  virtual void visit(LIR_OpVisitState* visitor) {

    visitor->do_slow_case(_info);

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("ArrayStoreExceptionStub"); }

#endif // PRODUCT

};

class ArrayCopyStub: public CodeStub {

 private:

  LIR_OpArrayCopy* _op;

 public:

  ArrayCopyStub(LIR_OpArrayCopy* op): _op(op) { }

  LIR_Opr src() const                         { return _op->src(); }

  LIR_Opr src_pos() const                     { return _op->src_pos(); }

  LIR_Opr dst() const                         { return _op->dst(); }

  LIR_Opr dst_pos() const                     { return _op->dst_pos(); }

  LIR_Opr length() const                      { return _op->length(); }

  LIR_Opr tmp() const                         { return _op->tmp(); }

  virtual void emit_code(LIR_Assembler* e);

  virtual CodeEmitInfo* info() const          { return _op->info(); }

  virtual void visit(LIR_OpVisitState* visitor) {

    // don't pass in the code emit info since it's processed in the fast path

    visitor->do_slow_case();

  }

#ifndef PRODUCT

  virtual void print_name(outputStream* out) const { out->print("ArrayCopyStub"); }

#endif // PRODUCT

};

//////////////////////////////////////////////////////////////////////////////////////////

#ifndef SERIALGC

// Code stubs for Garbage-First barriers.

class G1PreBarrierStub: public CodeStub {

 private:

  LIR_Opr _addr;

  LIR_Opr _pre_val;

  LIR_PatchCode _patch_code;

  CodeEmitInfo* _info;

 public:

  // pre_val (a temporary register) must be a register;