diff options
Diffstat (limited to 'sysdeps/s390/strncpy.S')
| -rw-r--r-- | sysdeps/s390/strncpy.S | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/sysdeps/s390/strncpy.S b/sysdeps/s390/strncpy.S new file mode 100644 index 0000000000..823eeb4f5e --- /dev/null +++ b/sysdeps/s390/strncpy.S @@ -0,0 +1,79 @@ +/* strncpy - copy at most n characters from a string from source to + destination. For IBM S390 + This file is part of the GNU C Library. + Copyright (C) 2000 Free Software Foundation, Inc. + Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com). + + The GNU C Library is free software ; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation ; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY ; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +/* + * R2 = address of destination (dst) + * R3 = address of source (src) + * R4 = max of bytes to copy + */ + +#include "sysdep.h" +#include "asm-syntax.h" + +ENTRY(strncpy) + .text + st %r2,24(%r15) # save dst pointer + slr %r2,%r3 # %r3 points to src, %r2+%r3 to dst + lhi %r1,3 + nr %r1,%r4 # last 2 bits of # bytes + srl %r4,2 + ltr %r4,%r4 # less than 4 bytes to copy ? + jz .L1 + bras %r5,.L0 # enter loop & load address of a 0 + .long 0 +.L0: icm %r0,8,0(%r3) # first byte + jz .L3 + icm %r0,4,1(%r3) # second byte + jz .L4 + icm %r0,2,2(%r3) # third byte + jz .L5 + icm %r0,1,3(%r3) # fourth byte + jz .L6 + st %r0,0(%r2,%r3) # store all four to dest. + la %r3,4(%r3) + brct %r4,.L0 +.L1: ltr %r1,%r1 + jz .Lexit +.L2: icm %r0,1,0(%r3) + stc %r0,0(%r2,%r3) + la %r3,1(%r3) + jz .L7 + brct %r1,.L2 + j .Lexit +.L3: icm %r0,4,0(%r5) +.L4: icm %r0,2,0(%r5) +.L5: icm %r0,1,0(%r5) +.L6: st %r0,0(%r2,%r3) + la %r3,4(%r3) + ahi %r4,-1 + j .L8 +.L7: ahi %r1,-1 +.L8: sll %r4,2 + alr %r4,%r1 + alr %r2,%r3 # start of dst area to be zeroed + lr %r3,%r4 + slr %r4,%r4 + slr %r5,%r5 +.L9: mvcle %r2,%r4,0 # pad dst with zeroes + jo .L9 +.Lexit: l %r2,24(%r15) # return dst pointer + br %r14 +END(strncpy) |