sysdeps/s390/s390-32/bzero.S

   1 /* bzero -- set a block of memory to zero.  IBM S390 version
   2    This file is part of the GNU C Library.
   3    Copyright (C) 2000, 2001 Free Software Foundation, Inc.
   4    Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
   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, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 /*
  22  * R2 = address to memory area
  23  * R3 = number of bytes to fill
  24  */
  25
  26 #include "sysdep.h"
  27 #include "asm-syntax.h"
  28
  29         .text
  30 ENTRY(__bzero)
  31         ltr     %r3,%r3
  32         jz      .L1
  33         sr      %r1,%r1             # set pad byte to zero
  34         sr      %r4,%r4             # no source for MVCLE, only a pad byte
  35         sr      %r5,%r5
  36 .L0:    mvcle   %r2,%r4,0(%r1)      # thats it, MVCLE is your friend
  37         jo      .L0
  38 .L1:    br      %r14
  39 END(__bzero)
  40
  41 #ifndef NO_WEAK_ALIAS
  42 weak_alias (__bzero, bzero)
  43 #endif