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

   1 /* Copyright (C) 1993, 1995, 1996 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by David Mosberger <davidm@cs.arizona.edu>, 1995.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 /* For compatibility only: a "long" is 64 bits on the Alpha, so
  21    llseek() isn't really needed.  But there are some programs out
  22    there who may depend on it being around.  */
  23
  24 #include <sysdep.h>
  25
  26         .text
  27 ENTRY(llseek)
  28 #ifdef PROF
  29         ldgp    gp, 0(pv)
  30         .set noat
  31         lda     AT, _mcount
  32         jsr     AT, (AT), _mcount
  33         .set at
  34         .prologue 1
  35 #else
  36         .prologue 0
  37 #endif
  38
  39         sll     a1, 32, a1      /* build a 64 bit ofs out of 32 bit operands */
  40         zap     a2, 0xf0, a2
  41         mov     a3, t0          /* save result address */
  42         bis     a2, a1, a1
  43
  44         mov     a4, a2          /* shift down whence */
  45
  46         ldi     v0, __NR_lseek
  47         call_pal PAL_callsys
  48         bne     a3, error
  49
  50         stq     v0, 0(t0)
  51         ret
  52
  53 error:
  54 #ifndef PROF
  55         br      gp, 1f
  56 1:      ldgp    gp, 0(gp)
  57 #endif
  58         jmp     zero, __syscall_error
  59
  60         END(llseek)