/* strncpy - copy at most n characters from a string from source to

   destination.  64 bit S/390 version

   Copyright (C) 2001-2018 Free Software Foundation, Inc.

   Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).

   This file is part of the GNU C Library.

   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, see

   <http://www.gnu.org/licenses/>.  */

/* INPUT PARAMETERS

     %r2 = address of destination (dst)

     %r3 = address of source (src)

     %r4 = max of bytes to copy.  */

#include <ifunc-strncpy.h>

#include "sysdep.h"

#include "asm-syntax.h"

#if HAVE_STRNCPY_Z900_G5

ENTRY(STRNCPY_Z900_G5)

	.text

	stg   %r2,48(%r15)	    # save dst pointer

	slgr  %r2,%r3		    # %r3 points to src, %r2+%r3 to dst

	lghi  %r1,7

	ngr   %r1,%r4		    # last 3 bits of # bytes

	srlg  %r4,%r4,3

	ltgr  %r4,%r4		    # less than 8 bytes to copy ?

	jz    .L1

	bras  %r5,.L0		    # enter loop & load address of a 0

	.long 0

.L0:	icmh  %r0,8,0(%r3)	    # first byte

	jz    .L3

	icmh  %r0,4,1(%r3)	    # second byte

	jz    .L4

	icmh  %r0,2,2(%r3)	    # third byte

	jz    .L5

	icmh  %r0,1,3(%r3)	    # fourth byte

	jz    .L6

	icm   %r0,8,4(%r3)	    # fifth byte

	jz    .L7

	icm   %r0,4,5(%r3)	    # sixth byte

	jz    .L8

	icm   %r0,2,6(%r3)	    # seventh byte

	jz    .L9

	icm   %r0,1,7(%r3)	    # eigth byte

	jz    .L10

	stg   %r0,0(%r2,%r3)	    # store all eight to dest.

	la    %r3,8(%r3)

	brct  %r4,.L0

.L1:	ltgr  %r1,%r1

	jz    .Lexit

.L2:	icm   %r0,1,0(%r3)

	stc   %r0,0(%r2,%r3)

	la    %r3,1(%r3)

	jz    .L11

	brct  %r1,.L2

	j     .Lexit

.L3:	icmh  %r0,4,0(%r5)

.L4:	icmh  %r0,2,0(%r5)

.L5:	icmh  %r0,1,0(%r5)

.L6:	icm   %r0,8,0(%r5)

.L7:	icm   %r0,4,0(%r5)

.L8:	icm   %r0,2,0(%r5)

.L9:	icm   %r0,1,0(%r5)

.L10:	stg   %r0,0(%r2,%r3)

	la    %r3,8(%r3)

	aghi  %r4,-1

	j     .L12

.L11:	aghi  %r1,-1

.L12:	sllg  %r4,%r4,3

	algr  %r4,%r1

	algr  %r2,%r3		    # start of dst area to be zeroed

	lgr   %r3,%r4

	slgr  %r4,%r4

	slgr  %r5,%r5

.L13:	mvcle %r2,%r4,0		    # pad dst with zeroes

	jo    .L13

.Lexit: lg    %r2,48(%r15)	    # return dst pointer

	br    %r14

END(STRNCPY_Z900_G5)

# if ! HAVE_STRNCPY_IFUNC

strong_alias (STRNCPY_Z900_G5, strncpy)

# endif

# if defined SHARED && IS_IN (libc)

strong_alias (STRNCPY_Z900_G5, __GI_strncpy)

# endif

#endif