sysdeps/unix/sysv/linux/alpha/swapcontext.S

   1 /* Save current context and install the given one.
   2    Copyright (C) 2004 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <sysdep.h>
  21 #include <ucontext-offsets.h>
  22
  23 ENTRY(__swapcontext)
  24
  25 #ifdef PROF
  26         ldgp    $29, 0($27)
  27         .set noat
  28         lda     AT, _mcount
  29         jsr     AT, (AT), _mcount
  30         .set at
  31         .prologue 1
  32 #elif defined PIC
  33         .prologue 0
  34 #else
  35         ldgp    $29, 0($27)
  36         .prologue 1
  37 #endif
  38
  39 #ifdef PIC
  40         unop
  41         bsr     $0, __getcontext_x      !samegp
  42         mov     $17, $16
  43         br      $31, __setcontext       !samegp
  44 #else
  45         jsr     $0, __getcontext_x
  46         mov     $17, $16
  47         jmp     $31, __setcontext
  48 #endif
  49
  50 END(__swapcontext)
  51 weak_alias (__swapcontext, swapcontext)