/* 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, 2001, 2003 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 Lesser General Public   License as published by the Free Software Foundation; either   version 2.1 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   Lesser General Public License for more details.   You should have received a copy of the GNU Lesser General Public   License along with the GNU C Library; 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    %r14END(strncpy)libc_hidden_builtin_def (strncpy)