1/* Vector Optimized 32/64 bit S/390 version of wmemcmp.
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-wmemcmp.h>
20#if HAVE_WMEMCMP_Z13
21
22# include "sysdep.h"
23# include "asm-syntax.h"
24
25	.text
26
27/* int wmemcmp (const wchar_t *s1, const wchar_t *s2, size_t n)
28   Compare at most n characters of two wchar_t-arrays.
29
30   Register usage:
31   -r0=tmp
32   -r1=number of blocks
33   -r2=s1
34   -r3=s2
35   -r4=n
36   -r5=current_len
37   -v16=part of s1
38   -v17=part of s2
39   -v18=index of unequal
40*/
41ENTRY(WMEMCMP_Z13)
42	.machine "z13"
43	.machinemode "zarch_nohighgprs"
44
45# if !defined __s390x__
46	llgfr	%r4,%r4
47# endif /* !defined __s390x__ */
48	clgije	%r4,0,.Lend_equal /* Nothing to do if n == 0.  */
49
50	/* Check range of maxlen and convert to byte-count.  */
51# ifdef __s390x__
52	tmhh	%r4,49152	/* Test bit 0 or 1 of maxlen.  */
53	lghi	%r1,-4		/* Max byte-count is 18446744073709551612.  */
54# else
55	tmlh	%r4,49152	/* Test bit 0 or 1 of maxlen.  */
56	llilf	%r1,4294967292	/* Max byte-count is 4294967292.  */
57# endif /* !__s390x__ */
58	sllg	%r4,%r4,2	/* Convert character-count to byte-count.  */
59	locgrne	%r4,%r1		/* Use max byte-count, if bit 0/1 was one.  */
60
61	lghi	%r5,0		/* current_len = 0.  */
62
63	clgijh	%r4,16,.Lgt16
64
65.Lremaining:
66	aghi	%r4,-1		/* vstl needs highest index.  */
67	vll	%v16,%r4,0(%r2)
68	vll	%v17,%r4,0(%r3)
69	vfenef	%v18,%v16,%v17	/* Compare not equal.  */
70	vlgvb	%r1,%v18,7	/* Load unequal index or 16 if not found.  */
71	clrj	%r1,%r4,12,.Lfound2 /* r1 <= r4 -> unequal within loaded
72					bytes.  */
73
74.Lend_equal:
75	lghi	%r2,0
76	br	%r14
77
78.Lfound:
79	/* vfenezf found an unequal element or zero.
80	   This instruction compares unsigned words, but wchar_t is signed.
81	   Thus we have to compare the found element again.  */
82	vlgvb	%r1,%v18,7	/* Extract not equal byte-index.  */
83.Lfound2:
84	srl	%r1,2		/* And convert it to character-index.  */
85	vlgvf	%r0,%v16,0(%r1)	/* Load character-values.  */
86	vlgvf	%r1,%v17,0(%r1)
87	cr	%r0,%r1
88	je	.Lend_equal
89	lghi	%r2,1
90	lghi	%r1,-1
91	locgrl	%r2,%r1
92	br	%r14
93
94.Lgt16:
95	clgijh	%r4,64,.Lpreloop64
96
97.Lpreloop16:
98	srlg	%r1,%r4,4	/* Split into 16byte blocks */
99.Lloop16:
100	vl	%v16,0(%r5,%r2)
101	vl	%v17,0(%r5,%r3)
102	aghi	%r5,16
103	vfenefs	%v18,%v16,%v17	/* Compare not equal.  */
104	jno	.Lfound
105	brctg	%r1,.Lloop16	/* Loop until all blocks are processed.  */
106
107	llgfr	%r4,%r4
108	nilf	%r4,15		/* Get remaining bytes */
109	locgre	%r2,%r4
110	ber	%r14
111	la	%r2,0(%r5,%r2)
112	la	%r3,0(%r5,%r3)
113	j	.Lremaining
114
115.Lpreloop64:
116	srlg	%r1,%r4,6	/* Split into 64byte blocks */
117.Lloop64:
118	vl	%v16,0(%r5,%r2)
119	vl	%v17,0(%r5,%r3)
120	vfenefs	%v18,%v16,%v17	/* Compare not equal.  */
121	jno	.Lfound
122
123	vl	%v16,16(%r5,%r2)
124	vl	%v17,16(%r5,%r3)
125	vfenefs	%v18,%v16,%v17
126	jno	.Lfound
127
128	vl	%v16,32(%r5,%r2)
129	vl	%v17,32(%r5,%r3)
130	vfenefs	%v18,%v16,%v17
131	jno	.Lfound
132
133	vl	%v16,48(%r5,%r2)
134	vl	%v17,48(%r5,%r3)
135	aghi	%r5,64
136	vfenefs	%v18,%v16,%v17
137	jno	.Lfound
138
139	brctg	%r1,.Lloop64	/* Loop until all blocks are processed.  */
140
141	llgfr	%r4,%r4
142	nilf	%r4,63		/* Get remaining bytes */
143	locgre	%r2,%r4
144	ber	%r14
145	clgijh	%r4,16,.Lpreloop16
146	la	%r2,0(%r5,%r2)
147	la	%r3,0(%r5,%r3)
148	j	.Lremaining
149END(WMEMCMP_Z13)
150
151# if ! HAVE_WMEMCMP_IFUNC
152strong_alias (WMEMCMP_Z13, __wmemcmp)
153weak_alias (__wmemcmp, wmemcmp)
154# endif
155#endif
156