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
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
|
/* Vector optimized 32/64 bit S/390 version of wcsncpy.
Copyright (C) 2015-2024 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
<https://www.gnu.org/licenses/>. */
#include <ifunc-wcsncpy.h>
#if HAVE_WCSNCPY_Z13
# include "sysdep.h"
# include "asm-syntax.h"
.text
/* wchar_t *wcsncpy (const wchar_t *dest, const wchar_t *src, size_t n)
Copy at most n characters of string src to dest.
Register usage:
-r0=dest pointer for return
-r1=tmp, zero byte index
-r2=dest
-r3=src
-r4=n
-r5=current_len
-r6=tmp, loaded bytes
-r7=tmp, border
-v16=part of src
-v17=index of zero
-v18=part of src
-v31=register save area for r6, r7
*/
ENTRY(WCSNCPY_Z13)
.machine "z13"
.machinemode "zarch_nohighgprs"
# if !defined __s390x__
llgfr %r4,%r4
# endif /* !defined __s390x__ */
clgfi %r4,0
ber %r14 /* Nothing to do, if n == 0. */
vlbb %v16,0(%r3),6 /* Load s until next 4k-byte boundary. */
tmll %r3,3 /* Test if s is 4-byte aligned? */
jne .Lfallback /* And use common-code variant if not. */
vlvgp %v31,%r6,%r7 /* Save registers. */
lgr %r0,%r2 /* Save destination pointer for return. */
lcbb %r6,0(%r3),6 /* Get bytes to 4k-byte boundary or 16. */
llgfr %r6,%r6 /* Convert 32bit to 64bit. */
lghi %r5,0 /* current_len = 0. */
/* Check range of maxlen and convert to byte-count. */
# ifdef __s390x__
tmhh %r4,49152 /* Test bit 0 or 1 of n. */
lghi %r1,-4 /* Max byte-count is 18446744073709551612. */
# else
tmlh %r4,49152 /* Test bit 0 or 1 of n. */
llilf %r1,4294967292 /* Max byte-count is 4294967292. */
# endif /* !__s390x__ */
sllg %r4,%r4,2 /* Convert character-count to byte-count. */
locgrne %r4,%r1 /* Use max byte-count, if bit 0/1 was one. */
clgrjle %r4,%r6,.Lremaining_v16 /* If n <= loaded-bytes
-> process remaining. */
/* n > loaded-byte-count. */
vfenezf %v17,%v16,%v16 /* Find element not equal with zero search. */
vlgvb %r1,%v17,7 /* Load zero index or 16 if not found. */
aghi %r1,3 /* Also copy remaining bytes of zero. */
clrjl %r1,%r6,.Lfound_v16_store /* Found zero within loaded bytes,
copy and return. */
/* Align s to 16 byte. */
risbgn %r7,%r3,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15. */
lghi %r5,15 /* current_len = 15. */
slr %r5,%r7 /* Compute highest index to 16byte boundary. */
/* Zero not found and n > loaded-byte-count. */
vstl %v16,%r5,0(%r2) /* Copy loaded characters - no zero. */
ahi %r5,1 /* Start loop at next character. */
/* Now we are 16byte aligned, so we can load
a full vreg without page fault. */
lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */
aghi %r1,64
clgrjl %r1,%r4,.Lloop64
vl %v16,0(%r5,%r3) /* Load s. */
clgijl %r4,17,.Lremaining_v16 /* If n <=16, process remaining
bytes. */
.Llt64:
lgr %r7,%r4
slgfi %r7,16 /* border_len = maxlen - 16. */
clgrjhe %r5,%r7,.Lremaining_v16 /* If current_len >= border
then process remaining bytes. */
vfenezfs %v17,%v16,%v16 /* Find element not equal with zero search. */
je .Lfound_v16 /* Jump away if zero was found. */
vl %v18,16(%r5,%r3) /* Load next part of s. */
vst %v16,0(%r5,%r2) /* Store previous part without zero to dst. */
aghi %r5,16
clgrjhe %r5,%r7,.Lremaining_v18
vfenezfs %v17,%v18,%v18
je .Lfound_v18
vl %v16,16(%r5,%r3)
vst %v18,0(%r5,%r2)
aghi %r5,16
clgrjhe %r5,%r7,.Lremaining_v16
vfenezfs %v17,%v16,%v16
je .Lfound_v16
vl %v18,16(%r5,%r3)
vst %v16,0(%r5,%r2)
aghi %r5,16
.Lremaining_v18:
vlr %v16,%v18
.Lremaining_v16:
/* v16 contains the remaining bytes [1...16].
Store remaining bytes and append string-termination. */
vfenezf %v17,%v16,%v16 /* Find element not equal with zero search. */
slgrk %r7,%r4,%r5 /* Remaining bytes = maxlen - current_len. */
aghi %r7,-1 /* vstl needs highest index. */
la %r2,0(%r5,%r2) /* vstl has no index register. */
vlgvb %r1,%v17,7 /* Load zero index or 16 if not found. */
aghi %r1,3 /* Also copy remaining bytes of zero. */
/* Zero in remaining bytes? -> jump away (zero-index < max-index)
Do not jump away if zero-index == max-index,
but simply copy zero with vstl below. */
clrjl %r1,%r7,.Lfound_v16_store
vstl %v16,%r7,0(%r2) /* Store remaining bytes without null
termination!. */
.Lend:
/* Restore saved registers. */
vlgvg %r6,%v31,0
vlgvg %r7,%v31,1
lgr %r2,%r0 /* Load saved dest-ptr. */
br %r14
.Lfound_v16_32:
aghi %r5,32
j .Lfound_v16
.Lfound_v18_48:
aghi %r5,32
.Lfound_v18_16:
aghi %r5,16
.Lfound_v18:
vlr %v16,%v18
.Lfound_v16:
/* v16 contains a zero. Store remaining bytes to zero. current_len
has not reached border, thus checking for n is not needed! */
vlgvb %r1,%v17,7 /* Load byte index of zero. */
la %r2,0(%r5,%r2) /* vstl has no support for index-register. */
aghi %r1,3 /* Also copy remaining bytes of zero. */
.Lfound_v16_store:
vstl %v16,%r1,0(%r2) /* Copy characters including zero. */
/* Fill remaining bytes with zero - remaining count always > 0. */
algr %r5,%r1 /* Remaining bytes (=%r4) = ... */
slgr %r4,%r5 /* = maxlen - (currlen + zero_index + 1). */
la %r2,0(%r1,%r2) /* Pointer to zero. start filling beyond. */
aghi %r4,-2 /* mvc with exrl needs count - 1.
(additional -1, see remaining bytes above) */
srlg %r6,%r4,8 /* Split into 256 byte blocks. */
ltgr %r6,%r6
je .Lzero_lt256
.Lzero_loop256:
mvc 1(256,%r2),0(%r2) /* Fill 256 zeros at once. */
la %r2,256(%r2)
brctg %r6,.Lzero_loop256 /* Loop until all blocks are processed. */
.Lzero_lt256:
exrl %r4,.Lmvc_lt256
j .Lend
.Lmvc_lt256:
mvc 1(1,%r2),0(%r2)
/* Find zero in 16byte aligned loop. */
.Lloop64:
vl %v16,0(%r5,%r3) /* Load s. */
vfenezfs %v17,%v16,%v16 /* Find element not equal with zero search. */
je .Lfound_v16 /* Jump away if zero was found. */
vl %v18,16(%r5,%r3) /* Load next part of s. */
vst %v16,0(%r5,%r2) /* Store previous part without zero to dst. */
vfenezfs %v17,%v18,%v18
je .Lfound_v18_16
vl %v16,32(%r5,%r3)
vst %v18,16(%r5,%r2)
vfenezfs %v17,%v16,%v16
je .Lfound_v16_32
vl %v18,48(%r5,%r3)
vst %v16,32(%r5,%r2)
vfenezfs %v17,%v18,%v18
je .Lfound_v18_48
vst %v18,48(%r5,%r2)
aghi %r5,64
lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */
aghi %r1,64
clgrjl %r1,%r4,.Lloop64
vl %v16,0(%r5,%r3) /* Load s. */
j .Llt64
.Lfallback:
jg WCSNCPY_C
END(WCSNCPY_Z13)
# if ! HAVE_WCSNCPY_IFUNC
strong_alias (WCSNCPY_Z13, __wcsncpy)
weak_alias (__wcsncpy, wcsncpy)
# endif
#endif
|
