/*

 * Copyright (c) 2008, 2014, 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 CPU_ARM_VM_VM_VERSION_ARM_HPP

#define CPU_ARM_VM_VM_VERSION_ARM_HPP

#include "runtime/globals_extension.hpp"

#include "runtime/vm_version.hpp"

class VM_Version: public Abstract_VM_Version {

  friend class JVMCIVMStructs;

  static bool _has_simd;

 protected:

  // Are we done with vm version initialization

  static bool _is_initialized;

 public:

  static void initialize();

  static bool is_initialized()      { return _is_initialized; }

 protected:

  enum Feature_Flag {

    vfp = 0,

    vfp3_32 = 1,

    simd = 2,

  };

  enum Feature_Flag_Set {

    unknown_m           = 0,

    all_features_m      = -1,

    vfp_m     = 1 << vfp,

    vfp3_32_m = 1 << vfp3_32,

    simd_m    = 1 << simd,

  };

  // The value stored by "STR PC, [addr]" instruction can be either

  // (address of this instruction + 8) or (address of this instruction + 12)

  // depending on hardware implementation.

  // This adjustment is calculated in runtime.

  static int _stored_pc_adjustment;

  // ARM architecture version: 5 = ARMv5, 6 = ARMv6, 7 = ARMv7 etc.

  static int _arm_arch;

  // linux kernel atomic helper function version info

  // __kuser_cmpxchg() if version >= 2

  // __kuser_cmpxchg64() if version >= 5

  static int _kuser_helper_version;

#define KUSER_HELPER_VERSION_ADDR 0xffff0ffc

#define KUSER_VERSION_CMPXCHG32 2

#define KUSER_VERSION_CMPXCHG64 5

  // Read additional info using OS-specific interfaces

  static void get_os_cpu_info();

 public:

  static void early_initialize();

  static int arm_arch()             { return _arm_arch; }

  static int stored_pc_adjustment() { return _stored_pc_adjustment; }

  static bool supports_rev()        { return _arm_arch >= 6; }

  static bool supports_ldrex()      { return _arm_arch >= 6; }

  static bool supports_movw()       { return _arm_arch >= 7; }

  static bool supports_ldrexd()     { return _arm_arch >= 7; }

  static bool supports_compare_and_exchange() { return true; }

  static bool supports_kuser_cmpxchg32() { return _kuser_helper_version >= KUSER_VERSION_CMPXCHG32; }

  static bool supports_kuser_cmpxchg64() { return _kuser_helper_version >= KUSER_VERSION_CMPXCHG64; }

  // Override Abstract_VM_Version implementation

  static bool use_biased_locking();

  static bool has_vfp()             { return (_features & vfp_m) != 0; }

  static bool has_vfp3_32()         { return (_features & vfp3_32_m) != 0; }

  static bool has_simd()            { return (_features & simd_m) != 0; }

  static bool simd_math_is_compliant() { return false; }

  static bool prefer_moves_over_load_literal() { return supports_movw(); }

  friend class VM_Version_StubGenerator;

};

#endif // CPU_ARM_VM_VM_VERSION_ARM_HPP