1/* Vector optimized 32/64 bit S/390 version of memmem.
2 Copyright (C) 2019-2022 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-memmem.h>
20#if HAVE_MEMMEM_ARCH13
21# include "sysdep.h"
22# include "asm-syntax.h"
23 .text
24
25/* void *memmem(const void *haystack=r2, size_t haystacklen=r3,
26 const void *needle=r4, size_t needlelen=r5);
27 Locate a substring. */
28ENTRY(MEMMEM_ARCH13)
29 .machine "arch13"
30 .machinemode "zarch_nohighgprs"
31# if ! defined __s390x__
32 llgfr %r3,%r3
33 llgfr %r5,%r5
34 llgfr %r4,%r4
35 llgfr %r2,%r2
36# endif /* ! defined __s390x__ */
37 clgrjl %r3,%r5,.Lend_no_match /* Haystack < needle? */
38
39 /* Jump to fallback if needle > 9. See also strstr-arch13.S. */
40# if ! HAVE_MEMMEM_Z13
41# error The arch13 variant of memmem needs the z13 variant of memmem!
42# endif
43 clgfi %r5,9
44 jgh MEMMEM_Z13
45
46 aghik %r0,%r5,-1 /* vll needs highest index. */
47 bc 4,0(%r14) /* cc==1: return if needle-len == 0. */
48 vll %v18,%r0,0(%r4) /* Load needle. */
49 vlvgb %v19,%r5,7 /* v19[7] contains length of needle. */
50
51 clgijh %r3,16,.Lhaystack_larger_16
52.Lhaystack_smaller_16_on_bb:
53 aghik %r0,%r3,-1 /* vll needs highest index. */
54 vll %v16,%r0,0(%r2) /* Load haystack. */
55.Lhaystack_smaller_16:
56 sgr %r3,%r5 /* r3 = largest valid match-index. */
57 jl .Lend_no_match /* Haystack-len < needle-len? */
58 vstrs %v20,%v16,%v18,%v19,0,0
59 /* Vector string search without zero search where v20 will contain
60 the index of a partial/full match or 16 (index is named k).
61 cc=0 (no match; k=16): .Lend_no_match
62 cc=1 (only available with zero-search): Ignore
63 cc=2 (full match; k<16): Needle found, but could be beyond haystack!
64 cc=3 (partial match; k<16): Always at end of v16 and thus beyond! */
65 brc 9,.Lend_no_match /* Jump away if cc == 0 || cc == 3. */
66 vlgvb %r1,%v20,7
67 /* Verify that the full-match (cc=2) is valid! */
68 clgrjh %r1,%r3,.Lend_no_match /* Jump away if match is beyond. */
69 la %r2,0(%r1,%r2)
70 br %r14
71.Lend_no_match:
72 lghi %r2,0
73 br %r14
74
75.Lhaystack_larger_16:
76 vl %v16,0(%r2)
77 lghi %r1,17
78 lay %r4,-16(%r3,%r2) /* Boundary for loading with vl. */
79 lay %r0,-64(%r3,%r2) /* Boundary for loading with 4xvl. */
80 /* See also strstr-arch13.S:
81 min-skip-partial-match-index = (16 - n_len) + 1 */
82 sgr %r1,%r5
83 clgfi %r3,64 /* Set Boundary to zero ... */
84 la %r3,0(%r3,%r2)
85 locghil %r0,0 /* ... if haystack < 64bytes. */
86 jh .Lloop64
87.Lloop:
88 la %r2,16(%r2)
89 /* Vector string search with zero search. cc=0 => no match. */
90 vstrs %v20,%v16,%v18,%v19,0,0
91 jne .Lloop_vstrs_nonzero_cc
92 clgrjh %r2,%r4,.Lhaystack_too_small
93.Lloop16:
94 vl %v16,0(%r2)
95 la %r2,16(%r2)
96 vstrs %v20,%v16,%v18,%v19,0,0
97 jne .Lloop_vstrs_nonzero_cc
98 clgrjle %r2,%r4,.Lloop16
99.Lhaystack_too_small:
100 sgr %r3,%r2 /* r3 = (haystack + len) - curr_pos */
101 je .Lend_no_match /* Remaining haystack is empty. */
102 lcbb %r0,0(%r2),6
103 jo .Lhaystack_smaller_16_on_bb
104 vl %v16,0(%r2) /* Load haystack. */
105 j .Lhaystack_smaller_16
106
107.Lend_match_found:
108 vlgvb %r4,%v20,7
109 sgr %r2,%r1
110 la %r2,0(%r4,%r2)
111 br %r14
112
113.Lloop_vstrs_nonzero_cc32:
114 la %r2,16(%r2)
115.Lloop_vstrs_nonzero_cc16:
116 la %r2,16(%r2)
117.Lloop_vstrs_nonzero_cc0:
118 la %r2,16(%r2)
119.Lloop_vstrs_nonzero_cc:
120 lay %r2,-16(%r1,%r2) /* Compute next load address. */
121 jh .Lend_match_found /* cc == 2 (full match) */
122 clgrjh %r2,%r4,.Lhaystack_too_small
123 vl %v16,0(%r2)
124.Lloop_vstrs_nonzero_cc_loop:
125 la %r2,0(%r1,%r2)
126 vstrs %v20,%v16,%v18,%v19,0,0
127 jh .Lend_match_found
128 clgrjh %r2,%r4,.Lhaystack_too_small
129 vl %v16,0(%r2) /* Next part of haystack. */
130 jo .Lloop_vstrs_nonzero_cc_loop
131 /* Case: no-match. */
132 clgrjh %r2,%r0,.Lloop /* Jump away if haystack has less than 64b. */
133.Lloop64:
134 vstrs %v20,%v16,%v18,%v19,0,0
135 jne .Lloop_vstrs_nonzero_cc0
136 vl %v16,16(%r2) /* Next part of haystack. */
137 vstrs %v20,%v16,%v18,%v19,0,0
138 jne .Lloop_vstrs_nonzero_cc16
139 vl %v16,32(%r2) /* Next part of haystack. */
140 vstrs %v20,%v16,%v18,%v19,0,0
141 jne .Lloop_vstrs_nonzero_cc32
142 vl %v16,48(%r2) /* Next part of haystack. */
143 la %r2,64(%r2)
144 vstrs %v20,%v16,%v18,%v19,0,0
145 jne .Lloop_vstrs_nonzero_cc
146 clgrjh %r2,%r4,.Lhaystack_too_small
147 vl %v16,0(%r2) /* Next part of haystack. */
148 clgrjle %r2,%r0,.Lloop64
149 j .Lloop
150END(MEMMEM_ARCH13)
151
152# if ! HAVE_MEMMEM_IFUNC
153strong_alias (MEMMEM_ARCH13, __memmem)
154weak_alias (__memmem, memmem)
155# endif
156
157# if MEMMEM_Z13_ONLY_USED_AS_FALLBACK && defined SHARED && IS_IN (libc)
158weak_alias (MEMMEM_ARCH13, __GI_memmem)
159strong_alias (MEMMEM_ARCH13, __GI___memmem)
160# endif
161#endif
162

source code of glibc/sysdeps/s390/memmem-arch13.S