nptl/sysdeps/unix/sysv/linux/sparc/sparc64/cpu_relax.S

   1 /* CPU strand yielding for busy loops.
   2    Copyright (C) 2012-2014 Free Software Foundation, Inc.
   3    Contributed by David S. Miller (davem@davemloft.net)
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C 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 GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <sysdep.h>
  21
  22         .text
  23 __cpu_relax_generic:
  24         rd      %ccr, %g0
  25         rd      %ccr, %g0
  26         rd      %ccr, %g0
  27         retl
  28          nop
  29         .size   __cpu_relax_generic,.-__cpu_relax_generic
  30
  31 __cpu_relax_pause:
  32         wr      %g0, 128, %asr27
  33         retl
  34          nop
  35         .size   __cpu_relax_pause,.-__cpu_relax_pause
  36
  37 ENTRY(__cpu_relax)
  38         .type   __cpu_relax, @gnu_indirect_function
  39 # ifdef SHARED
  40         SETUP_PIC_REG_LEAF(o3, o5)
  41 # endif
  42         set     HWCAP_SPARC_PAUSE, %o1
  43         andcc   %o0, %o1, %g0
  44         be      1f
  45          nop
  46 # ifdef SHARED
  47         sethi   %gdop_hix22(__cpu_relax_pause), %o1
  48         xor     %o1, %gdop_lox10(__cpu_relax_pause), %o1
  49 # else
  50         set     __cpu_relax_pause, %o1
  51 # endif
  52         ba      10f
  53          nop
  54 1:
  55 # ifdef SHARED
  56         sethi   %gdop_hix22(__cpu_relax_generic), %o1
  57         xor     %o1, %gdop_lox10(__cpu_relax_generic), %o1
  58 # else
  59         set     __cpu_relax_generic, %o1
  60 # endif
  61 10:
  62 # ifdef SHARED
  63         add     %o3, %o1, %o1
  64 # endif
  65         retl
  66          mov    %o1, %o0
  67 END(__cpu_relax)