sysdeps/s390/s390-32/memcpy.S

   1 /* memcpy - copy a block from source to destination.  S/390 version.
   2    Copyright (C) 2012-2018 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19
  20 #include "sysdep.h"
  21 #include "asm-syntax.h"
  22
  23 /* INPUT PARAMETERS
  24      %r2 = address of destination memory area
  25      %r3 = address of source memory area
  26      %r4 = number of bytes to copy.  */
  27
  28        .text
  29 ENTRY(__mempcpy)
  30         .machine "g5"
  31         lr      %r1,%r2             # Use as dest
  32         la      %r2,0(%r4,%r2)      # Return dest + n
  33         j       .L_G5_start
  34 END(__mempcpy)
  35 #ifndef USE_MULTIARCH
  36 libc_hidden_def (__mempcpy)
  37 weak_alias (__mempcpy, mempcpy)
  38 libc_hidden_builtin_def (mempcpy)
  39 #endif
  40
  41 ENTRY(memcpy)
  42         .machine "g5"
  43         lr      %r1,%r2             # r1: Use as dest ; r2: Return dest
  44 .L_G5_start:
  45         ltr     %r4,%r4
  46         je      .L_G5_99
  47         ahi     %r4,-1
  48         lr      %r5,%r4
  49         srl     %r5,8
  50         ltr     %r5,%r5
  51         jne     .L_G5_13
  52 .L_G5_4:
  53         basr    %r5,0
  54 .L_G5_16:
  55         ex      %r4,.L_G5_17-.L_G5_16(%r5)
  56 .L_G5_99:
  57         br      %r14
  58 .L_G5_13:
  59         chi     %r5,4096            # Switch to mvcle for copies >1MB
  60         jh      __memcpy_mvcle
  61 .L_G5_12:
  62         mvc     0(256,%r1),0(%r3)
  63         la      %r1,256(%r1)
  64         la      %r3,256(%r3)
  65         brct    %r5,.L_G5_12
  66         j       .L_G5_4
  67 .L_G5_17:
  68         mvc     0(1,%r1),0(%r3)
  69 END(memcpy)
  70 #ifndef USE_MULTIARCH
  71 libc_hidden_builtin_def (memcpy)
  72 #endif
  73
  74 ENTRY(__memcpy_mvcle)
  75         # Using as standalone function will result in unexpected
  76         # results since the length field is incremented by 1 in order to
  77         # compensate the changes already done in the functions above.
  78         lr      %r0,%r2             # backup return dest [ + n ]
  79         ahi     %r4,1               # length + 1
  80         lr      %r5,%r4             # source length
  81         lr      %r4,%r3             # source address
  82         lr      %r2,%r1             # destination address
  83         lr      %r3,%r5             # destination length = source length
  84 .L_MVCLE_1:
  85         mvcle   %r2,%r4,0           # thats it, MVCLE is your friend
  86         jo      .L_MVCLE_1
  87         lr      %r2,%r0             # return destination address
  88         br      %r14
  89 END(__memcpy_mvcle)