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

source code of glibc/sysdeps/s390/wmemcmp-vx.S