Line data    Source code

       1             : /* src/vm/jit/x86_64/atomic.hpp - x86_64 atomic instructions
       2             : 
       3             :    Copyright (C) 1996-2013
       4             :    CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
       5             : 
       6             :    This file is part of CACAO.
       7             : 
       8             :    This program is free software; you can redistribute it and/or
       9             :    modify it under the terms of the GNU General Public License as
      10             :    published by the Free Software Foundation; either version 2, or (at
      11             :    your option) any later version.
      12             : 
      13             :    This program is distributed in the hope that it will be useful, but
      14             :    WITHOUT ANY WARRANTY; without even the implied warranty of
      15             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      16             :    General Public License for more details.
      17             : 
      18             :    You should have received a copy of the GNU General Public License
      19             :    along with this program; if not, write to the Free Software
      20             :    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
      21             :    02110-1301, USA.
      22             : 
      23             : */
      24             : 
      25             : 
      26             : #ifndef MD_ATOMIC_HPP_
      27             : #define MD_ATOMIC_HPP_ 1
      28             : 
      29             : #include "config.h"
      30             : 
      31             : #include <stdint.h>
      32             : 
      33             : #include "threads/atomic.hpp"
      34             : 
      35             : namespace Atomic_md {
      36             : 
      37             : /**
      38             :  * An atomic compare and swap for 32-bit integer values.
      39             :  *
      40             :  * @param p      Pointer to memory address.
      41             :  * @param oldval Old value to be expected.
      42             :  * @param newval New value to be stored.
      43             :  *
      44             :  * @return value of the memory location before the store
      45             :  */
      46          33 : inline uint32_t compare_and_swap(volatile uint32_t *p, uint32_t oldval, uint32_t newval)
      47             : {
      48             :         uint32_t result;
      49             : 
      50             :         __asm__ __volatile__ ("lock; cmpxchgl %2, %1"
      51             :                                                   : "=a" (result), "=m" (*p)
      52             :                                                   : "r" (newval), "m" (*p), "0" (oldval)
      53          33 :                                                   : "cc");
      54             : 
      55          33 :         return result;
      56             : }
      57             : 
      58             : 
      59             : /**
      60             :  * An atomic compare and swap for 64-bit integer values.
      61             :  *
      62             :  * @param p      Pointer to memory address.
      63             :  * @param oldval Old value to be expected.
      64             :  * @param newval New value to be stored.
      65             :  *
      66             :  * @return value of the memory location before the store
      67             :  */
      68     1422601 : inline uint64_t compare_and_swap(volatile uint64_t *p, uint64_t oldval, uint64_t newval)
      69             : {
      70             :         uint64_t result;
      71             : 
      72             :         __asm__ __volatile__ ("lock; cmpxchgq %2, %1"
      73             :                                                   : "=a" (result), "=m" (*p)
      74             :                                                   : "r" (newval), "m" (*p), "0" (oldval)
      75     1422601 :                                                   : "cc");
      76             : 
      77     1422605 :         return result;
      78             : }
      79             : 
      80             : 
      81             : /**
      82             :  * A memory barrier.
      83             :  */
      84     1215128 : inline void memory_barrier(void)
      85             : {
      86     1215128 :         __asm__ __volatile__ ("mfence" : : : "memory");
      87     1215129 : }
      88             : 
      89             : 
      90             : /**
      91             :  * A write memory barrier.
      92             :  */
      93     1241150 : inline void write_memory_barrier(void)
      94             : {
      95     1241150 :         __asm__ __volatile__ ("" : : : "memory");
      96     1241150 : }
      97             : 
      98             : 
      99             : /**
     100             :  * An instruction barrier.
     101             :  */
     102     1235165 : inline void instruction_barrier(void)
     103             : {
     104             :         // We need the "memory" constraint here because compare_and_swap does not
     105             :         // have it.
     106     1235165 :         __asm__ __volatile__ ("" : : : "memory");
     107     1235165 : }
     108             : 
     109             : }
     110             : 
     111             : #endif // MD_ATOMIC_HPP_
     112             : 
     113             : 
     114             : /*
     115             :  * These are local overrides for various environment variables in Emacs.
     116             :  * Please do not remove this and leave it at the end of the file, where
     117             :  * Emacs will automagically detect them.
     118             :  * ---------------------------------------------------------------------
     119             :  * Local variables:
     120             :  * mode: c++
     121             :  * indent-tabs-mode: t
     122             :  * c-basic-offset: 4
     123             :  * tab-width: 4
     124             :  * End:
     125             :  * vim:noexpandtab:sw=4:ts=4:
     126             :  */