/* Vector optimized 32/64 bit S/390 version of strnlen.

   Copyright (C) 2015-2018 Free Software Foundation, Inc.

   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/>.  */

#include <ifunc-strnlen.h>

#if HAVE_STRNLEN_Z13

# include "sysdep.h"

# include "asm-syntax.h"

	.text

/* size_t strnlen (const char *s, size_t maxlen)

   Returns the number of characters in s or at most maxlen.

   Register usage:

   -r1=tmp

   -r2=address of string

   -r3=maxlen (number of characters to be read)

   -r4=tmp

   -r5=current_len and return_value

   -v16=part of s

*/

ENTRY(STRNLEN_Z13)

	.machine "z13"

	.machinemode "zarch_nohighgprs"

# if !defined __s390x__

	llgfr	%r3,%r3

# endif /* !defined __s390x__ */

	clgfi	%r3,0		/* if maxlen == 0, return 0.  */

	locgre	%r2,%r3

	ber	%r14

	vlbb	%v16,0(%r2),6	/* Load s until next 4k-byte boundary.  */

	lcbb	%r1,0(%r2),6	/* Get bytes to 4k-byte boundary or 16.  */

	llgfr	%r1,%r1		/* Convert 32bit to 64bit.  */

	vfenezb	%v16,%v16,%v16	/* Find element not equal with zero search.  */

	clgr	%r1,%r3

	locgrh	%r1,%r3		/* loaded_byte_count

				   = min (loaded_byte_count, maxlen)  */

	vlgvb	%r5,%v16,7	/* Load zero index or 16 if not found.  */

	clr	%r5,%r1		/* If found zero within loaded bytes?  */

	locgrl	%r2,%r5		/* Then copy return value.  */

	blr	%r14		/* And return.  */

	clgr	%r1,%r3		/* If loaded_byte_count == maxlen?  */

	locgre	%r2,%r3		/* Then copy return value.  */

	ber	%r14		/* And return.  */

	/* Align s to 16 byte.  */

	risbgn	%r4,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15.  */

	lghi	%r5,16		/* current_len = 16.  */

	slr	%r5,%r4		/* Compute bytes to 16bytes boundary.  */

	lgr	%r1,%r5		/* If %r5 + 64 < maxlen? -> loop64.  */

	aghi	%r1,64

	clgrjl	%r1,%r3,.Lloop64

	/* Find zero in max 64byte with aligned s.  */

.Llt64:

	vl	%v16,0(%r5,%r2) /* Load s.  */

	vfenezbs %v16,%v16,%v16	/* Find element not equal with zero search.  */

	je	.Lfound		/* Jump away if zero was found.  */

	aghi	%r5,16

	clgrjhe	%r5,%r3,.Lfound /* current_len >= maxlen -> end.  */

	vl	%v16,0(%r5,%r2)

	vfenezbs %v16,%v16,%v16

	je	.Lfound

	aghi	%r5,16

	clgrjhe	%r5,%r3,.Lfound

	vl	%v16,0(%r5,%r2)

	vfenezbs %v16,%v16,%v16

	je	.Lfound

	aghi	%r5,16

	clgrjhe	%r5,%r3,.Lfound

	vl	%v16,0(%r5,%r2)

	vfenezbs %v16,%v16,%v16

	j	.Lfound

.Lfound48:

	aghi	%r5,16

.Lfound32:

	aghi	%r5,16

.Lfound16:

	aghi	%r5,16

.Lfound:

	vlgvb	%r4,%v16,7	/* Load byte index of zero or 16 if no zero.  */

	algr	%r5,%r4

	clgr	%r5,%r3

	locgrh	%r5,%r3		/* Return min (current_len, maxlen).  */

	lgr	%r2,%r5

	br	%r14

	/* Find zero in 16 byte aligned loop.  */

.Lloop64:

	vl	%v16,0(%r5,%r2) /* Load s.  */

	vfenezbs %v16,%v16,%v16	/* Find element not equal with zero search.  */

	je	.Lfound		/* Jump away if zero was found.  */

	vl	%v16,16(%r5,%r2)

	vfenezbs %v16,%v16,%v16

	je	.Lfound16

	vl	%v16,32(%r5,%r2)

	vfenezbs %v16,%v16,%v16

	je	.Lfound32

	vl	%v16,48(%r5,%r2)

	vfenezbs %v16,%v16,%v16

	je	.Lfound48

	aghi	%r5,64

	lgr	%r1,%r5		/* If %r5 + 64 < maxlen? -> loop64.  */

	aghi	%r1,64

	clgrjl	%r1,%r3,.Lloop64

	j	.Llt64

END(STRNLEN_Z13)

# if ! HAVE_STRNLEN_IFUNC

strong_alias (STRNLEN_Z13, __strnlen)

weak_alias (__strnlen, strnlen)

# endif

# if ! HAVE_STRNLEN_C && defined SHARED && IS_IN (libc)

strong_alias (STRNLEN_Z13, __GI_strnlen)

strong_alias (STRNLEN_Z13, __GI___strnlen)

# endif

#endif /* HAVE_STRNLEN_Z13  */