libstdc++-v3/config/cpu/powerpc/bits/atomicity.h

   1 // Low-level functions for atomic operations: PowerPC version  -*- C++ -*-
   2
   3 // Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 #ifndef _BITS_ATOMICITY_H
  31 #define _BITS_ATOMICITY_H       1
  32
  33 typedef int _Atomic_word;
  34
  35 static inline _Atomic_word
  36 __attribute__ ((__unused__))
  37 __exchange_and_add (volatile _Atomic_word* __mem, int __val)
  38 {
  39   _Atomic_word __tmp, __res;
  40   __asm__ __volatile__ (
  41         "/* Inline exchange & add */\n"
  42         "0:\t"
  43         "lwarx    %0,0,%2 \n\t"
  44         "add%I3   %1,%0,%3 \n\t"
  45         "stwcx.   %1,0,%2 \n\t"
  46         "bne-     0b \n\t"
  47         "/* End exchange & add */"
  48         : "=&b"(__res), "=&r"(__tmp)
  49         : "r" (__mem), "Ir"(__val)
  50         : "cr0", "memory");
  51   return __res;
  52 }
  53
  54 static inline void
  55 __attribute__ ((__unused__))
  56 __atomic_add (volatile _Atomic_word *__mem, int __val)
  57 {
  58   _Atomic_word __tmp;
  59   __asm__ __volatile__ (
  60         "/* Inline atomic add */\n"
  61         "0:\t"
  62         "lwarx    %0,0,%1 \n\t"
  63         "add%I2   %0,%0,%2 \n\t"
  64         "stwcx.   %0,0,%1 \n\t"
  65         "bne-     0b \n\t"
  66         "/* End atomic add */"
  67         : "=&b"(__tmp)
  68         : "r" (__mem), "Ir"(__val)
  69         : "cr0", "memory");
  70 }
  71
  72 static inline long
  73 __attribute__ ((__unused__))
  74 __always_swap (volatile long *__p, long int __newval)
  75 {
  76   long __res;
  77   __asm__ __volatile__ (
  78         "/* Inline always swap */\n"
  79         "0:\t"
  80         "lwarx    %0,0,%1 \n\t"
  81         "stwcx.   %2,0,%1 \n\t"
  82         "bne-     0b \n\t"
  83         "/* End always swap */"
  84         : "=&r"(__res)
  85         : "r"(__p), "r"(__newval)
  86         : "cr0", "memory");
  87   return __res;
  88 }
  89
  90 static inline int
  91 __attribute__ ((__unused__))
  92 __test_and_set (volatile long *__p, long int __newval)
  93 {
  94   int __res;
  95   __asm__ __volatile__ (
  96         "/* Inline test & set */\n"
  97         "0:\t"
  98         "lwarx    %0,0,%1 \n\t"
  99         "cmpwi    %0,0 \n\t"
 100         "bne-     1f \n\t"
 101         "stwcx.   %2,0,%1 \n\t"
 102         "bne-     0b \n"
 103         "1:\n\t"
 104         "/* End test & set */"
 105         : "=&r"(__res)
 106         : "r"(__p), "r"(__newval)
 107         : "cr0", "memory");
 108   return __res;
 109 }
 110
 111 #endif /* atomicity.h */
 112