/*

 * Copyright (c) 1999, 2018, 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"

#include "compiler/compilerDefinitions.hpp"

#include "compiler/compilerDirectives.hpp"

typedef void (*initializer)(void);

#if INCLUDE_JVMCI

// Per-compiler statistics

class CompilerStatistics {

  friend class VMStructs;

  class Data {

    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();

 private:

  const CompilerType _type;

#if INCLUDE_JVMCI

  CompilerStatistics _stats;

#endif

 public:

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

  // 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; }

  virtual bool can_compile_method(const methodHandle& method)  { 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,

  //    the command-line compile ommand, or a compiler directive)

  //  - 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 directive provides the compilation context and includes pre-evaluated values

  // dependent on VM flags, compile commands, and compiler directives.

  //

  // Usually, the compilation context is the caller of the method 'method'.

  // The only case when for a non-recursive method 'method' the compilation context

  // is not the caller of the 'method' (but it is the method itself) is

  // java.lang.ref.Referene::get.

  // For java.lang.ref.Reference::get, the intrinsic version is used

  // instead of the compiled version so that the value in the referent

  // field can be registered by the G1 pre-barrier code. The intrinsified

  // version of Reference::get also adds a memory barrier to prevent

  // commoning reads from the referent field across safepoint since GC

  // can change the referent field's value. See Compile::Compile()

  // in src/share/vm/opto/compile.cpp or

  // GraphBuilder::GraphBuilder() in src/share/vm/c1/c1_GraphBuilder.cpp

  // for more details.

  virtual bool is_intrinsic_available(const methodHandle& method, DirectiveSet* directive) {

    return is_intrinsic_supported(method) &&

           !directive->is_intrinsic_disabled(method) &&

           !vmIntrinsics::is_disabled_by_flags(method);

  }

  // 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.

  virtual bool is_intrinsic_supported(const methodHandle& method) {

    return false;

  }

  // Compiler type queries.

  const bool is_c1()                             { return _type == compiler_c1; }

  const bool is_c2()                             { return _type == compiler_c2; }

  const bool is_jvmci()                          { return _type == compiler_jvmci; }

  const CompilerType type()                      { return _type; }

  // Extra tests to identify trivial methods for the tiered compilation policy.

  virtual bool is_trivial(Method* method) { return false; }

  // 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, DirectiveSet* directive) {

    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