/*

 * Copyright (c) 1999, 2015, 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.

 *

 */

#ifndef SHARE_VM_COMPILER_ABSTRACTCOMPILER_HPP

#define SHARE_VM_COMPILER_ABSTRACTCOMPILER_HPP

#include "ci/compilerInterface.hpp"

typedef void (*initializer)(void);

#if INCLUDE_JVMCI

// Per-compiler statistics

class CompilerStatistics VALUE_OBJ_CLASS_SPEC {

  friend class VMStructs;

  class Data VALUE_OBJ_CLASS_SPEC {

    friend class VMStructs;

  public:

    elapsedTimer _time;  // time spent compiling

    int _bytes;          // number of bytecodes compiled, including inlined bytecodes

    int _count;          // number of compilations

    Data() : _bytes(0), _count(0) {}

    void update(elapsedTimer time, int bytes) {

      _time.add(time);

      _bytes += bytes;

      _count++;

    }

    void reset() {

      _time.reset();

    }

  };

 public:

  Data _standard;  // stats for non-OSR compilations

  Data _osr;       // stats for OSR compilations

  int _nmethods_size; //

  int _nmethods_code_size;

  int bytes_per_second() {

    int bytes = _standard._bytes + _osr._bytes;

    if (bytes == 0) {

      return 0;

    }

    double seconds = _standard._time.seconds() + _osr._time.seconds();

    return seconds == 0.0 ? 0 : (int) (bytes / seconds);

  }

  CompilerStatistics() : _nmethods_size(0), _nmethods_code_size(0) {}

};

#endif // INCLUDE_JVMCI

class AbstractCompiler : public CHeapObj<mtCompiler> {

 private:

  volatile int _num_compiler_threads;

 protected:

  volatile int _compiler_state;

  // Used for tracking global state of compiler runtime initialization

  enum { uninitialized, initializing, initialized, failed, shut_down };

  // This method returns true for the first compiler thread that reaches that methods.

  // This thread will initialize the compiler runtime.

  bool should_perform_init();

  // The (closed set) of concrete compiler classes.

  enum Type {

    none,

    c1,

    c2,

    jvmci,

    shark

  };

 private:

  Type _type;

#if INCLUDE_JVMCI

  CompilerStatistics _stats;

#endif

 public:

  AbstractCompiler(Type type) : _type(type), _compiler_state(uninitialized), _num_compiler_threads(0) {}

  // This function determines the compiler thread that will perform the

  // shutdown of the corresponding compiler runtime.

  bool should_perform_shutdown();

  // Name of this compiler

  virtual const char* name() = 0;

  // Missing feature tests

  virtual bool supports_native()                 { return true; }

  virtual bool supports_osr   ()                 { return true; }

  // Determine if the current compiler provides an intrinsic

  // for method 'method'. An intrinsic is available if:

  //  - the intrinsic is enabled (by using the appropriate command-line flag) and

  //  - the platform on which the VM is running supports the intrinsic

  //    (i.e., the platform provides the instructions necessary for the compiler

  //    to generate the intrinsic code).

  //

  // The second parameter, 'compilation_context', is needed to implement functionality

  // related to the DisableIntrinsic command-line flag. The DisableIntrinsic flag can

  // be used to prohibit the compilers to use an intrinsic. There are three ways to

  // disable an intrinsic using the DisableIntrinsic flag:

  //

  // (1) -XX:DisableIntrinsic=_hashCode,_getClass

  //     Disables intrinsification of _hashCode and _getClass globally

  //     (i.e., the intrinsified version the methods will not be used at all).

  // (2) -XX:CompileCommand=option,aClass::aMethod,ccstr,DisableIntrinsic,_hashCode

  //     Disables intrinsification of _hashCode if it is called from

  //     aClass::aMethod (but not for any other call site of _hashCode)

  // (3) -XX:CompileCommand=option,java.lang.ref.Reference::get,ccstr,DisableIntrinsic,_Reference_get

  //     Some methods are not compiled by C2. Instead, the C2 compiler

  //     returns directly the intrinsified version of these methods.

  //     The command above forces C2 to compile _Reference_get, but

  //     allows using the intrinsified version of _Reference_get at all

  //     other call sites.

  //

  // From the modes above, (1) disable intrinsics globally, (2) and (3)

  // disable intrinsics on a per-method basis. In cases (2) and (3) the

  // compilation context is aClass::aMethod and java.lang.ref.Reference::get,

  // respectively.

    return is_intrinsic_supported(method) &&

           !vmIntrinsics::is_disabled_by_flags(method, compilation_context);

  }

  // Determines if an intrinsic is supported by the compiler, that is,

  // the compiler provides the instructions necessary to generate

  // the intrinsic code for method 'method'.

  //

  // The 'is_intrinsic_supported' method is a white list, that is,

  // by default no intrinsics are supported by a compiler except

  // the ones listed in the method. Overriding methods should conform

  // to this behavior.

    return false;

  }

  // Compiler type queries.

  bool is_c1()                                   { return _type == c1; }

  bool is_c2()                                   { return _type == c2; }

  bool is_jvmci()                                { return _type == jvmci; }

  bool is_shark()                                { return _type == shark; }

  // Customization

  virtual void initialize () = 0;

  void set_num_compiler_threads(int num) { _num_compiler_threads = num;  }

  int num_compiler_threads()             { return _num_compiler_threads; }

  // Get/set state of compiler objects

  bool is_initialized()           { return _compiler_state == initialized; }

  bool is_failed     ()           { return _compiler_state == failed;}

  void set_state     (int state);

  void set_shut_down ()           { set_state(shut_down); }

  // Compilation entry point for methods

  virtual void compile_method(ciEnv* env, ciMethod* target, int entry_bci) {

    ShouldNotReachHere();

  }

  // Print compilation timers and statistics

  virtual void print_timers() {

    ShouldNotReachHere();

  }

#if INCLUDE_JVMCI

  CompilerStatistics* stats() { return &_stats; }

#endif

};

#endif // SHARE_VM_COMPILER_ABSTRACTCOMPILER_HPP