1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
|
/* Vector optimized 32/64 bit S/390 version of strstr.
Copyright (C) 2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <ifunc-strstr.h>
#if HAVE_STRSTR_ARCH13
# include "sysdep.h"
# include "asm-syntax.h"
.text
/* char *strstr (const char *haystack=r2, const char *needle=r3)
Locate a substring. */
ENTRY(STRSTR_ARCH13)
.machine "arch13"
.machinemode "zarch_nohighgprs"
lcbb %r1,0(%r3),6
jo .Lneedle_on_bb /* Needle on block-boundary? */
vl %v18,0(%r3),6 /* Load needle. */
vfenezb %v19,%v18,%v18 /* v19[7] contains the length of needle. */
.Lneedle_loaded:
vlgvb %r4,%v19,7 /* Get index of zero or 16 if not found. */
lghi %r5,17 /* See below: min-skip-partial-match-index. */
cgibe %r4,0,0(%r14) /* Test if needle is zero and return. */
/* The vstrs instruction is able to handle needles up to a length of 16,
but then we may have to load the next part of haystack with a
small offset. This will be slow - see examples:
haystack =mmmmmmmmmmmmmmmm mmmmmmmmmmmmmmmmmm...mmmmmmmmmmmmmmmmmmma
needle = mmmmmmmmmmmmmma0
=> needle_len=15; vstrs reports a partial match; haystack+=2
haystack =mmmmmmmmmmmmmmmm mmmmmmmmmmmmmmmmmm...mmmmmmmmmmmmmmmmmmma
needle = mmmmmmmma0000000
=> needle_len=9; vstrs reports a partial match; haystack+=8 */
# if ! HAVE_STRSTR_Z13
# error The arch13 variant of strstr needs the z13 variant of strstr!
# endif
clgfi %r4,9
jh STRSTR_Z13
/* In case of a partial match, the vstrs instruction returns the index
of the partial match in a vector-register. Then we have to
reload the string at the "current-position plus this index" and run
vstrs again in order to determine if it was a full match or no match.
Transferring this index from vr to gr, compute the haystack-address
and loading with vl is quite slow as all instructions have data
dependencies. Thus we assume, that a partial match is always at the
first possible index and just load the next part of haystack from
there instead of waiting until the correct index is computed:
min-skip-partial-match-index = (16 - n_len) + 1 */
sgr %r5,%r4
.Lloop:
lcbb %r1,0(%r2),6
jo .Lloop_haystack_on_bb /* Haystack on block-boundary? */
vl %v16,0(%r2) /* Load next part of haystack. */
.Lloop_haystack_loaded:
/* Vector string search with zero search (cc=0 => no match). */
vstrs %v20,%v16,%v18,%v19,0,2
jne .Lloop_vstrs_nonzero_cc
lcbb %r1,16(%r2),6 /* Next part of haystack. */
jo .Lloop_haystack_on_bb16
vl %v16,16(%r2)
vstrs %v20,%v16,%v18,%v19,0,2
jne .Lloop_vstrs_nonzero_cc16
lcbb %r1,32(%r2),6 /* Next part of haystack. */
jo .Lloop_haystack_on_bb32
vl %v16,32(%r2)
vstrs %v20,%v16,%v18,%v19,0,2
jne .Lloop_vstrs_nonzero_cc32
lcbb %r1,48(%r2),6 /* Next part of haystack. */
jo .Lloop_haystack_on_bb48
vl %v16,48(%r2)
vstrs %v20,%v16,%v18,%v19,0,2
jne .Lloop_vstrs_nonzero_cc48
la %r2,64(%r2)
j .Lloop
.Lloop_vstrs_nonzero_cc48:
la %r2,16(%r2)
.Lloop_vstrs_nonzero_cc32:
la %r2,16(%r2)
.Lloop_vstrs_nonzero_cc16:
la %r2,16(%r2)
.Lloop_vstrs_nonzero_cc:
jh .Lend_match_found /* cc == 2 (full match) */
jl .Lend_no_match /* cc == 1 (no match, end of string) */
/* cc == 3 (partial match) See above: min-skip-partial-match-index! */
lcbb %r1,0(%r5,%r2),6
la %r2,0(%r5,%r2)
jo .Lloop_haystack_on_bb
vl %v16,0(%r2)
vstrs %v20,%v16,%v18,%v19,0,2
.Lloop_vstrs_nonzero_cc_loop:
jh .Lend_match_found
jl .Lend_no_match
la %r2,0(%r5,%r2)
je .Lloop
lcbb %r1,0(%r2),6 /* Next part of haystack. */
jo .Lloop_haystack_on_bb
vl %v16,0(%r2)
vstrs %v20,%v16,%v18,%v19,0,2
jh .Lend_match_found
jl .Lend_no_match
la %r2,0(%r5,%r2)
je .Lloop
lcbb %r1,0(%r2),6 /* Next part of haystack. */
jo .Lloop_haystack_on_bb
vl %v16,0(%r2)
vstrs %v20,%v16,%v18,%v19,0,2
jh .Lend_match_found
jl .Lend_no_match
la %r2,0(%r5,%r2)
je .Lloop
lcbb %r1,0(%r2),6 /* Next part of haystack. */
jo .Lloop_haystack_on_bb
vl %v16,0(%r2)
vstrs %v20,%v16,%v18,%v19,0,2
j .Lloop_vstrs_nonzero_cc_loop
.Lend_no_match:
lghi %r2,0
br %r14
.Lend_match_found:
vlgvb %r4,%v20,7
la %r2,0(%r4,%r2)
br %r14
.Lloop_haystack_on_bb48:
la %r2,16(%r2)
.Lloop_haystack_on_bb32:
la %r2,16(%r2)
.Lloop_haystack_on_bb16:
la %r2,16(%r2)
.Lloop_haystack_on_bb:
/* Haystack located on page-boundary. */
ahi %r1,-1 /* vll needs highest index instead of count. */
vll %v16,%r1,0(%r2)
vlvgb %v21,%r1,7
vfenezb %v17,%v16,%v16 /* Search zero in loaded haystack bytes. */
veclb %v17,%v21 /* Zero index <= loaded byte index? */
jle .Lloop_haystack_loaded /* -> v16 contains full haystack. */
vl %v16,0(%r2) /* Load haystack beyond page boundary. */
j .Lloop_haystack_loaded
.Lneedle_on_bb:
/* Needle located on page-boundary. */
ahi %r1,-1 /* vll needs highest index instead of count. */
vll %v18,%r1,0(%r3)
vlvgb %v21,%r1,7
vfenezb %v19,%v18,%v18 /* Search zero in loaded needle bytes. */
veclb %v19,%v21 /* Zero index <= max loaded byte index? */
jle .Lneedle_loaded /* -> v18 contains full needle. */
vl %v16,0(%r3) /* Load needle beyond page boundary. */
vfenezb %v19,%v18,%v18
j .Lneedle_loaded
END(STRSTR_ARCH13)
# if ! HAVE_STRSTR_IFUNC
strong_alias (STRSTR_ARCH13, strstr)
# endif
# if STRSTR_Z13_ONLY_USED_AS_FALLBACK && defined SHARED && IS_IN (libc)
strong_alias (STRSTR_ARCH13, __GI_strstr)
# endif
#endif
|
