1/* Vector optimized 32/64 bit S/390 version of strlen.
2   Copyright (C) 2015-2022 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   <https://www.gnu.org/licenses/>.  */
18
19#include <ifunc-strlen.h>
20#if HAVE_STRLEN_Z13
21
22# include "sysdep.h"
23# include "asm-syntax.h"
24
25	.text
26
27/* size_t strlen (const char *s)
28   Returns length of string s.
29
30   Register usage:
31   -r1=bytes to 4k-byte boundary
32   -r2=s
33   -r3=tmp
34   -r4=tmp
35   -r5=current_len and return_value
36   -v16=part of s
37*/
38ENTRY(STRLEN_Z13)
39	.machine "z13"
40	.machinemode "zarch_nohighgprs"
41
42	vlbb	%v16,0(%r2),6	/* Load s until next 4k-byte boundary.  */
43	lcbb	%r1,0(%r2),6	/* Get bytes to 4k-byte boundary or 16.  */
44
45	vfenezb	%v16,%v16,%v16	/* Find element not equal with zero search.  */
46	vlgvb	%r4,%v16,7	/* Load zero index or 16 if not found.  */
47	clr	%r4,%r1		/* If found zero within loaded bytes?  */
48	locgrl	%r2,%r4		/* Then copy return value.  */
49	blr	%r14		/* And return.  */
50
51	/* Align s to 16 byte.  */
52	risbgn	%r3,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15.  */
53	lghi	%r5,16		/* current_len = 16.  */
54	slr	%r5,%r3		/* Compute bytes to 16bytes boundary.  */
55
56	/* Find zero in 16 byte aligned loop.  */
57.Lloop:
58	vl	%v16,0(%r5,%r2)	/* Load s.  */
59	vfenezbs %v16,%v16,%v16 /* Find element not equal with zero search.  */
60	je	.Lfound		/* Jump away if zero was found.  */
61	vl	%v16,16(%r5,%r2)
62	vfenezbs %v16,%v16,%v16
63	je	.Lfound16
64	vl	%v16,32(%r5,%r2)
65	vfenezbs %v16,%v16,%v16
66	je	.Lfound32
67	vl	%v16,48(%r5,%r2)
68	vfenezbs %v16,%v16,%v16
69	je	.Lfound48
70
71	aghi	%r5,64
72	j	.Lloop		/* No zero found -> loop.  */
73
74.Lfound48:
75	aghi	%r5,16
76.Lfound32:
77	aghi	%r5,16
78.Lfound16:
79	aghi	%r5,16
80.Lfound:
81	vlgvb	%r2,%v16,7	/* Load byte index of zero.  */
82	algr	%r2,%r5
83	br	%r14
84END(STRLEN_Z13)
85
86# if ! HAVE_STRLEN_IFUNC
87strong_alias (STRLEN_Z13, strlen)
88# endif
89
90# if ! HAVE_STRLEN_C && defined SHARED && IS_IN (libc)
91strong_alias (STRLEN_Z13, __GI_strlen)
92# endif
93#endif
94