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
|
/* Vector optimized 32/64 bit S/390 version of stpncpy.
Copyright (C) 2015-2019 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-stpncpy.h>
#if HAVE_STPNCPY_Z13
# include "sysdep.h"
# include "asm-syntax.h"
.text
/* char * stpncpy (char *dest, const char *src, size_t n)
Copies at most n characters of string src to dest
returning a pointer to its end or dest+n
if src is smaller than n.
Register usage:
-%r0 = return value
-%r1 = zero byte index
-%r2 = curr dst pointer
-%r3 = curr src pointer
-%r4 = n
-%r5 = current_len
-%r6 = loaded bytes
-%r7 = border, tmp
*/
ENTRY(STPNCPY_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. */
la %r0,0(%r4,%r2) /* Save destination pointer + n for return. */
vlvgp %v31,%r6,%r7 /* Save registers. */
vlbb %v16,0(%r3),6 /* Load s until next 4k-byte boundary. */
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. */
clgrjle %r4,%r6,.Lremaining_v16 /* If n <= loaded-bytes
-> process remaining. */
/* n > loaded-byte-count */
vfenezb %v17,%v16,%v16 /* Find element not equal with zero search. */
vlgvb %r1,%v17,7 /* Load zero index or 16 if not found. */
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 = n - 16. */
clgrjhe %r5,%r7,.Lremaining_v16 /* If current_len >= border
then process remaining bytes. */
vfenezbs %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) /* Save previous part without zero to dst. */
aghi %r5,16
clgrjhe %r5,%r7,.Lremaining_v18
vfenezbs %v17,%v18,%v18
je .Lfound_v18
vl %v16,16(%r5,%r3)
vst %v18,0(%r5,%r2)
aghi %r5,16
clgrjhe %r5,%r7,.Lremaining_v16
vfenezbs %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. */
vfenezb %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. */
/* Zero in remaining bytes? -> jump away (zero-index <= max-index). */
clrjle %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. */
.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. */
lgr %r0,%r2 /* Save return-pointer to found zero. */
clgije %r4,1,.Lend /* Skip zero-filling, if found zero is last
possible character.
(1 is substracted from r4 below!). */
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)
.Lloop64:
vl %v16,0(%r5,%r3)
vfenezbs %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) /* Save previous part without zero to dst. */
vfenezbs %v17,%v18,%v18
je .Lfound_v18_16
vl %v16,32(%r5,%r3)
vst %v18,16(%r5,%r2)
vfenezbs %v17,%v16,%v16
je .Lfound_v16_32
vl %v18,48(%r5,%r3)
vst %v16,32(%r5,%r2)
vfenezbs %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
END(STPNCPY_Z13)
# if ! HAVE_STPNCPY_IFUNC
strong_alias (STPNCPY_Z13, __stpncpy)
weak_alias (__stpncpy, stpncpy)
# endif
# if ! HAVE_STPNCPY_C && defined SHARED && IS_IN (libc)
strong_alias (STPNCPY_Z13, __GI___stpncpy)
# endif
#endif
|
