1/* Vector optimized 32/64 bit S/390 version of strcat.
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-strcat.h>
20#if HAVE_STRCAT_Z13
21
22# include "sysdep.h"
23# include "asm-syntax.h"
24
25	.text
26
27/* char * strcat (const char *dest, const char *src)
28   Concatenate two strings.
29
30   Register usage:
31   -r0=saved dest pointer for return
32   -r1=tmp
33   -r2=dest
34   -r3=src
35   -r4=tmp
36   -r5=current_len
37   -v16=part of src
38   -v17=index of zero
39   -v18=part of src
40*/
41ENTRY(STRCAT_Z13)
42	.machine "z13"
43	.machinemode "zarch_nohighgprs"
44
45	lgr	%r0,%r2		/* Save destination pointer for return.  */
46
47	/* STRLEN
48	   r1 = loaded bytes (tmp)
49	   r4 = zero byte index (tmp)
50	   r2 = dst
51	*/
52	vlbb	%v16,0(%r2),6	/* Load s until next 4k-byte boundary.  */
53	lcbb	%r1,0(%r2),6	/* Get bytes to 4k-byte boundary or 16.  */
54
55	vfenezb	%v16,%v16,%v16	/* Find element not equal with zero search.  */
56	vlgvb	%r5,%v16,7	/* Load zero index or 16 if not found.  */
57	clrjl	%r5,%r1,.Llen_end /* Found zero within loaded bytes, end.  */
58
59	/* Align s to 16 byte.  */
60	risbgn	%r1,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15.  */
61	lghi	%r5,16		/* current_len = 16.  */
62	slr	%r5,%r1		/* Compute bytes to 16bytes boundary.  */
63
64	/* Find zero in 16byte aligned loop.  */
65.Llen_loop:
66	vl	%v16,0(%r5,%r2)	/* Load s.  */
67	vfenezbs %v16,%v16,%v16	/* Find element not equal with zero search.  */
68	je	.Llen_found	/* Jump away if zero was found.  */
69	vl	%v16,16(%r5,%r2)
70	vfenezbs %v16,%v16,%v16
71	je	.Llen_found16
72	vl	%v16,32(%r5,%r2)
73	vfenezbs %v16,%v16,%v16
74	je	.Llen_found32
75	vl	%v16,48(%r5,%r2)
76	vfenezbs %v16,%v16,%v16
77	je	.Llen_found48
78
79	aghi	%r5,64
80	j	.Llen_loop	/* No zero -> loop.  */
81
82.Llen_found48:
83	aghi	%r5,16
84.Llen_found32:
85	aghi	%r5,16
86.Llen_found16:
87	aghi	%r5,16
88.Llen_found:
89	vlgvb	%r4,%v16,7	/* Load byte index of zero.  */
90	algr	%r5,%r4
91
92.Llen_end:
93	/* STRCPY
94	   %r1 = loaded bytes (tmp)
95	   %r4 = zero byte index (tmp)
96	   %r3 = curr src pointer
97	   %r2 = curr dst pointer
98	 */
99	la	%r2,0(%r5,%r2)	/* strcpy at end of dst-string.   */
100
101	vlbb	%v16,0(%r3),6	/* Load s until next 4k-byte boundary.  */
102	lcbb	%r1,0(%r3),6	/* Get bytes to 4k-byte boundary or 16.  */
103
104	vfenezb	%v17,%v16,%v16	/* Find element not equal with zero search.  */
105	vlgvb	%r5,%v17,7	/* Load zero index or 16 if not found.  */
106	clrjl	%r5,%r1,.Lcpy_found_align /* If found zero within loaded bytes,
107					     copy bytes before and return.  */
108
109	/* Align s to 16 byte.  */
110	risbgn	%r4,%r3,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15.  */
111	lghi	%r5,15		/* current_len = 15.  */
112	slr	%r5,%r4		/* Compute highest index to 16byte boundary.  */
113
114	vstl	%v16,%r5,0(%r2)	/* Copy loaded characters - no zero.  */
115	ahi	%r5,1		/* Start loop at next character.  */
116
117	/* Find zero in 16byte aligned loop.  */
118.Lcpy_loop:
119	vl	%v16,0(%r5,%r3)	/* Load s.  */
120	vfenezbs %v17,%v16,%v16	/* Find element not equal with zero search.  */
121	je	.Lcpy_found_v16_0 /* Jump away if zero was found.  */
122	vl	%v18,16(%r5,%r3)/* Load next part of s.  */
123	vst	%v16,0(%r5,%r2)	/* Store previous part without zero to dst.  */
124	vfenezbs %v17,%v18,%v18
125	je	.Lcpy_found_v18_16
126	vl	%v16,32(%r5,%r3)
127	vst	%v18,16(%r5,%r2)
128	vfenezbs %v17,%v16,%v16
129	je	.Lcpy_found_v16_32
130	vl	%v18,48(%r5,%r3)
131	vst	%v16,32(%r5,%r2)
132	vfenezbs %v17,%v18,%v18
133	je	.Lcpy_found_v18_48
134	vst	%v18,48(%r5,%r2)
135
136	aghi	%r5,64
137	j	.Lcpy_loop	/* No zero -> loop.  */
138
139.Lcpy_found_v16_32:
140	aghi	%r5,32
141.Lcpy_found_v16_0:
142	la	%r4,0(%r5,%r2)
143	vlgvb	%r1,%v17,7	/* Load byte index of zero.  */
144	vstl	%v16,%r1,0(%r4)	/* Copy characters including zero.  */
145	lgr	%r2,%r0		/* Load saved dest-ptr.  */
146	br	%r14
147
148.Lcpy_found_v18_48:
149	aghi	%r5,32
150.Lcpy_found_v18_16:
151	la	%r4,16(%r5,%r2)
152	vlgvb	%r1,%v17,7	/* Load byte index of zero.  */
153	vstl	%v18,%r1,0(%r4)	/* Copy characters including zero.  */
154	lgr	%r2,%r0		/* Load saved dest-ptr.  */
155	br	%r14
156
157.Lcpy_found_align:
158	vstl	%v16,%r5,0(%r2)	/* Copy characters including zero.  */
159	lgr	%r2,%r0		/* Load saved dest-ptr.  */
160	br	%r14
161END(STRCAT_Z13)
162
163# if ! HAVE_STRCAT_IFUNC
164strong_alias (STRCAT_Z13, strcat)
165# endif
166
167# if ! HAVE_STRCAT_C && defined SHARED && IS_IN (libc)
168strong_alias (STRCAT_Z13, __GI_strcat)
169# endif
170#endif
171