1/* Vector optimized 32/64 bit S/390 version of strcmp.
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-strcmp.h>
20#if HAVE_STRCMP_Z13
21
22# include "sysdep.h"
23# include "asm-syntax.h"
24
25 .text
26
27/* int strcmp (const char *s1, const char *s2)
28 Compare two strings
29
30 Register usage:
31 -r1=loaded byte count s1
32 -r2=s1
33 -r3=s2
34 -r4=loaded byte coutn s2, tmp
35 -r5=current_len
36 -v16=part of s1
37 -v17=part of s2
38 -v18=index of unequal
39*/
40ENTRY(STRCMP_Z13)
41 .machine "z13"
42 .machinemode "zarch_nohighgprs"
43
44 lghi %r5,0 /* current_len = 0. */
45
46.Lloop:
47 vlbb %v16,0(%r5,%r2),6 /* Load s1 to block boundary. */
48 vlbb %v17,0(%r5,%r3),6 /* Load s2 to block boundary. */
49 lcbb %r1,0(%r5,%r2),6 /* Get loaded byte count of s1. */
50 jo .Llt16_1 /* Jump away if vr is not fully loaded. */
51 lcbb %r4,0(%r5,%r3),6
52 jo .Llt16_2 /* Jump away if vr is not fully loaded. */
53 /* Both vrs are fully loaded. */
54 aghi %r5,16
55 vfenezbs %v18,%v16,%v17 /* Compare not equal with zero search. */
56 jno .Lfound
57
58 vlbb %v16,0(%r5,%r2),6
59 vlbb %v17,0(%r5,%r3),6
60 lcbb %r1,0(%r5,%r2),6
61 jo .Llt16_1
62 lcbb %r4,0(%r5,%r3),6
63 jo .Llt16_2
64 aghi %r5,16
65 vfenezbs %v18,%v16,%v17
66 jno .Lfound
67
68 vlbb %v16,0(%r5,%r2),6
69 vlbb %v17,0(%r5,%r3),6
70 lcbb %r1,0(%r5,%r2),6
71 jo .Llt16_1
72 lcbb %r4,0(%r5,%r3),6
73 jo .Llt16_2
74 aghi %r5,16
75 vfenezbs %v18,%v16,%v17
76 jno .Lfound
77
78 vlbb %v16,0(%r5,%r2),6
79 vlbb %v17,0(%r5,%r3),6
80 lcbb %r1,0(%r5,%r2),6
81 jo .Llt16_1
82 lcbb %r4,0(%r5,%r3),6
83 jo .Llt16_2
84 aghi %r5,16
85 vfenezbs %v18,%v16,%v17
86 jno .Lfound
87 j .Lloop
88
89.Llt16_1:
90 lcbb %r4,0(%r5,%r3),6 /* Get loaded byte count of s2. */
91.Llt16_2:
92 clr %r1,%r4
93 locrh %r1,%r4 /* Get minimum of bytes loaded in s1/2. */
94 algfr %r5,%r1 /* Add smallest loaded bytes to current_len. */
95 vfenezbs %v18,%v16,%v17 /* Compare not equal with zero search. */
96 vlgvb %r4,%v18,7 /* Get not equal index or 16 if all equal. */
97 clrjl %r4,%r1,.Lfound /* Jump away if miscompare is within loaded
98 bytes. */
99 j .Lloop
100
101.Lfound:
102 je .Lend_equal
103 lghi %r2,1
104 lghi %r1,-1
105 locgrl %r2,%r1
106 br %r14
107.Lend_equal:
108 lghi %r2,0
109 br %r14
110END(STRCMP_Z13)
111
112# if ! HAVE_STRCMP_IFUNC
113strong_alias (STRCMP_Z13, strcmp)
114# endif
115
116# if ! HAVE_STRCMP_Z900_G5 && defined SHARED && IS_IN (libc)
117strong_alias (STRCMP_Z13, __GI_strcmp)
118# endif
119#endif
120

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