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

   1 /* Copyright (C) 1993, 1995 Free Software Foundation, Inc.
   2    Contributed by David Mosberger (davidm@cs.arizona.edu).
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 /* For compatibility only: a "long" is 64 bits on the Alpha, so
  20    llseek() isn't really needed.  But there are some programs out
  21    there who may depend on it being around.  */
  22
  23 #include <sysdep.h>
  24
  25         .text
  26 ENTRY(llseek)
  27 #ifdef PROF
  28         ldgp    gp, 0(pv)
  29         lda     AT, _mcount
  30         jsr     AT, (AT), _mcount
  31         .prologue 1
  32 #else
  33         .prologue 0
  34 #endif
  35
  36         sll     a1, 32, a1      /* build a 64 bit ofs out of 32 bit operands */
  37         zap     a2, 0xf0, a2
  38         mov     a3, t0          /* save result address */
  39         bis     a2, a1, a1
  40
  41         mov     a4, a2          /* shift down whence */
  42
  43         ldi     v0, __NR_lseek
  44         call_pal PAL_callsys
  45         bne     a3, error
  46
  47         stq     v0, 0(t0)
  48         ret
  49
  50 error:
  51 #ifndef PROF
  52         br      gp, 1f
  53 1:      ldgp    gp, 0(gp)
  54 #endif
  55         jmp     zero, __syscall_error
  56
  57         END(llseek)