sysdeps/s390/s390-64/memset.S

   1 /* Set a block of memory to some byte value.  64 bit S/390 version.
   2    Copyright (C) 2001-2016 Free Software Foundation, Inc.
   3    Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
   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
  21 #include <sysdep.h>
  22 #include "asm-syntax.h"
  23
  24 /* INPUT PARAMETERS
  25      %r2 = address of memory area
  26      %r3 = byte to fill memory with
  27      %r4 = number of bytes to fill.  */
  28
  29        .text
  30
  31 #ifdef USE_MULTIARCH
  32 ENTRY(__memset_default)
  33 #else
  34 ENTRY(memset)
  35 #endif
  36         .machine "z900"
  37         ltgr    %r4,%r4
  38         je      .L_Z900_4
  39         stc     %r3,0(%r2)
  40         cghi    %r4,1
  41         lgr     %r1,%r2
  42         je      .L_Z900_4
  43         aghi    %r4,-2
  44         srlg    %r3,%r4,8
  45         ltgr    %r3,%r3
  46         jne     .L_Z900_14
  47 .L_Z900_3:
  48         larl    %r3,.L_Z900_18
  49         ex      %r4,0(%r3)
  50 .L_Z900_4:
  51         br      %r14
  52 .L_Z900_14:
  53         mvc     1(256,%r1),0(%r1)
  54         la      %r1,256(%r1)
  55         brctg   %r3,.L_Z900_14
  56         j       .L_Z900_3
  57 .L_Z900_18:
  58         mvc     1(1,%r1),0(%r1)
  59 #ifdef USE_MULTIARCH
  60 END(__memset_default)
  61 #else
  62 END(memset)
  63 libc_hidden_builtin_def (memset)
  64 #endif