/*

 * Copyright (c) 2016, 2017, 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.

 *

 */

#include "precompiled.hpp"

#include "asm/macroAssembler.hpp"

#include "runtime/sharedRuntime.hpp"

#include "vmreg_x86.inline.hpp"

#ifdef COMPILER1

#include "c1/c1_Runtime1.hpp"

#endif //COMPILER1

#define __ masm->

#ifdef COMPILER1

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

// Object.hashCode, System.identityHashCode can pull the hashCode from the

// header word instead of doing a full VM transition once it's been computed.

// Since hashCode is usually polymorphic at call sites we can't do this

// optimization at the call site without a lot of work.

void SharedRuntime::inline_check_hashcode_from_object_header(MacroAssembler* masm,

                                 const methodHandle& method,

                                 Register obj_reg,

                                 Register result) {

  Label slowCase;

  // Unlike for Object.hashCode, System.identityHashCode is static method and

  // gets object as argument instead of the receiver.

  if (method->intrinsic_id() == vmIntrinsics::_identityHashCode) {

    Label Continue;

    // return 0 for null reference input

    __ cmpptr(obj_reg, (int32_t)NULL_WORD);

    __ jcc(Assembler::notEqual, Continue);

    __ xorptr(result, result);

    __ ret(0);

    __ bind(Continue);

  }

  __ movptr(result, Address(obj_reg, oopDesc::mark_offset_in_bytes()));

  // check if locked

  __ testptr(result, markWord::unlocked_value);

  __ jcc(Assembler::zero, slowCase);

  if (UseBiasedLocking) {

    // Check if biased and fall through to runtime if so

    __ testptr(result, markWord::biased_lock_bit_in_place);

    __ jcc(Assembler::notZero, slowCase);

  }

  // get hash

#ifdef _LP64

  // Read the header and build a mask to get its hash field.

  // Depend on hash_mask being at most 32 bits and avoid the use of hash_mask_in_place

  // because it could be larger than 32 bits in a 64-bit vm. See markWord.hpp.

  __ shrptr(result, markWord::hash_shift);

  __ andptr(result, markWord::hash_mask);

#else

  __ andptr(result, markWord::hash_mask_in_place);

#endif //_LP64

  // test if hashCode exists

  __ jcc(Assembler::zero, slowCase);

#ifndef _LP64

  __ shrptr(result, markWord::hash_shift);

#endif

  __ ret(0);

  __ bind(slowCase);

}

#endif //COMPILER1