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d183b96e | 1 | /* Vector optimized 32/64 bit S/390 version of strncpy. |
6d7e8eda | 2 | Copyright (C) 2015-2023 Free Software Foundation, Inc. |
d183b96e SL |
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 | |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
d183b96e | 18 | |
d1bdbf38 SL |
19 | #include <ifunc-strncpy.h> |
20 | #include "sysdep.h" | |
21 | #include "asm-syntax.h" | |
d183b96e SL |
22 | |
23 | .text | |
24 | ||
d1bdbf38 | 25 | #if HAVE_STRNCPY_Z13 |
d183b96e SL |
26 | /* char * strncpy (const char *dest, const char *src, size_t n) |
27 | Copy at most n characters of string src to dest. | |
28 | ||
29 | Register usage: | |
30 | -r0=dest pointer for return | |
31 | -r1=tmp, zero byte index | |
32 | -r2=dest | |
33 | -r3=src | |
34 | -r4=n | |
35 | -r5=current_len | |
36 | -r6=tmp, loaded bytes | |
37 | -r7=tmp, border | |
38 | -v16=part of src | |
39 | -v17=index of zero | |
40 | -v18=part of src | |
41 | -v31=register save area for r6, r7 | |
42 | */ | |
d1bdbf38 | 43 | ENTRY(STRNCPY_Z13) |
d183b96e SL |
44 | .machine "z13" |
45 | .machinemode "zarch_nohighgprs" | |
46 | ||
47 | # if !defined __s390x__ | |
48 | llgfr %r4,%r4 | |
49 | # endif /* !defined __s390x__ */ | |
50 | ||
51 | clgfi %r4,0 | |
52 | ber %r14 /* Nothing to do, if n == 0. */ | |
53 | lgr %r0,%r2 /* Save destination pointer for return. */ | |
54 | vlvgp %v31,%r6,%r7 /* Save registers. */ | |
55 | ||
56 | vlbb %v16,0(%r3),6 /* Load s until next 4k-byte boundary. */ | |
57 | lcbb %r6,0(%r3),6 /* Get bytes to 4k-byte boundary or 16. */ | |
58 | llgfr %r6,%r6 /* Convert 32bit to 64bit. */ | |
59 | ||
60 | lghi %r5,0 /* current_len = 0. */ | |
61 | ||
62 | clgrjle %r4,%r6,.Lremaining_v16 /* If n <= loaded-bytes | |
63 | -> process remaining. */ | |
64 | ||
65 | /* n > loaded-byte-count. */ | |
66 | vfenezb %v17,%v16,%v16 /* Find element not equal with zero search. */ | |
67 | vlgvb %r1,%v17,7 /* Load zero index or 16 if not found. */ | |
68 | clrjl %r1,%r6,.Lfound_v16_store /* Found zero within loaded bytes, | |
69 | copy and return. */ | |
70 | ||
71 | /* Align s to 16 byte. */ | |
72 | risbgn %r7,%r3,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15. */ | |
73 | lghi %r5,15 /* current_len = 15. */ | |
74 | slr %r5,%r7 /* Compute highest index to 16byte boundary. */ | |
75 | ||
76 | /* Zero not found and n > loaded-byte-count. */ | |
77 | vstl %v16,%r5,0(%r2) /* Copy loaded characters - no zero. */ | |
78 | ahi %r5,1 /* Start loop at next character. */ | |
79 | ||
80 | /* Now we are 16byte aligned, so we can load | |
81 | a full vreg without page fault. */ | |
82 | lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */ | |
83 | aghi %r1,64 | |
84 | clgrjl %r1,%r4,.Lloop64 | |
85 | ||
86 | vl %v16,0(%r5,%r3) /* Load s. */ | |
87 | clgijl %r4,17,.Lremaining_v16 /* If n <= 16, process remaining | |
88 | bytes. */ | |
89 | .Llt64: | |
90 | lgr %r7,%r4 | |
91 | slgfi %r7,16 /* border_len = n - 16. */ | |
92 | ||
93 | clgrjhe %r5,%r7,.Lremaining_v16 /* If current_len >= border | |
94 | then process remaining bytes. */ | |
95 | vfenezbs %v17,%v16,%v16 /* Find element not equal with zero search. */ | |
96 | je .Lfound_v16 /* Jump away if zero was found. */ | |
97 | vl %v18,16(%r5,%r3) /* Load next part of s. */ | |
98 | vst %v16,0(%r5,%r2) /* Store previous part without zero to dst. */ | |
99 | aghi %r5,16 | |
100 | ||
101 | clgrjhe %r5,%r7,.Lremaining_v18 | |
102 | vfenezbs %v17,%v18,%v18 | |
103 | je .Lfound_v18 | |
104 | vl %v16,16(%r5,%r3) | |
105 | vst %v18,0(%r5,%r2) | |
106 | aghi %r5,16 | |
107 | ||
108 | clgrjhe %r5,%r7,.Lremaining_v16 | |
109 | vfenezbs %v17,%v16,%v16 | |
110 | je .Lfound_v16 | |
111 | vl %v18,16(%r5,%r3) | |
112 | vst %v16,0(%r5,%r2) | |
113 | aghi %r5,16 | |
114 | ||
115 | .Lremaining_v18: | |
116 | vlr %v16,%v18 | |
117 | .Lremaining_v16: | |
118 | /* v16 contains the remaining bytes [1...16]. | |
119 | Store remaining bytes and append string-termination. */ | |
120 | vfenezb %v17,%v16,%v16 /* Find element not equal with zero search. */ | |
121 | slgrk %r7,%r4,%r5 /* Remaining bytes = maxlen - current_len. */ | |
122 | aghi %r7,-1 /* vstl needs highest index. */ | |
123 | la %r2,0(%r5,%r2) /* vstl has no index register. */ | |
124 | vlgvb %r1,%v17,7 /* Load zero index or 16 if not found. */ | |
125 | /* Zero in remaining bytes? -> jump away (zero-index < max-index) | |
126 | Do not jump away if zero-index == max-index, | |
127 | but simply copy zero with vstl below. */ | |
128 | clrjl %r1,%r7,.Lfound_v16_store | |
129 | vstl %v16,%r7,0(%r2) /* Store remaining bytes without null | |
130 | termination!. */ | |
131 | .Lend: | |
132 | /* Restore saved registers. */ | |
133 | vlgvg %r6,%v31,0 | |
134 | vlgvg %r7,%v31,1 | |
135 | lgr %r2,%r0 /* Load saved dest-ptr. */ | |
136 | br %r14 | |
137 | ||
138 | ||
139 | .Lfound_v16_32: | |
140 | aghi %r5,32 | |
141 | j .Lfound_v16 | |
142 | .Lfound_v18_48: | |
143 | aghi %r5,32 | |
144 | .Lfound_v18_16: | |
145 | aghi %r5,16 | |
146 | .Lfound_v18: | |
147 | vlr %v16,%v18 | |
148 | .Lfound_v16: | |
149 | /* v16 contains a zero. Store remaining bytes to zero. current_len | |
150 | has not reached border, thus checking for n is not needed! */ | |
151 | vlgvb %r1,%v17,7 /* Load byte index of zero. */ | |
152 | la %r2,0(%r5,%r2) /* vstl has no support for index-register. */ | |
153 | .Lfound_v16_store: | |
154 | vstl %v16,%r1,0(%r2) /* Copy characters including zero. */ | |
155 | /* Fill remaining bytes with zero - remaining count always > 0. */ | |
156 | algr %r5,%r1 /* Remaining bytes (=%r4) = ... */ | |
157 | slgr %r4,%r5 /* = n - (current_len + zero_index + 1). */ | |
158 | la %r2,0(%r1,%r2) /* Pointer to zero. start filling beyond. */ | |
159 | aghi %r4,-2 /* mvc with exrl needs count - 1. | |
160 | (additional -1, see remaining bytes above) */ | |
161 | srlg %r6,%r4,8 /* Split into 256 byte blocks. */ | |
162 | ltgr %r6,%r6 | |
163 | je .Lzero_lt256 | |
164 | .Lzero_loop256: | |
165 | mvc 1(256,%r2),0(%r2) /* Fill 256 zeros at once. */ | |
166 | la %r2,256(%r2) | |
167 | brctg %r6,.Lzero_loop256 /* Loop until all blocks are processed. */ | |
168 | .Lzero_lt256: | |
169 | exrl %r4,.Lmvc_lt256 | |
170 | j .Lend | |
171 | .Lmvc_lt256: | |
172 | mvc 1(1,%r2),0(%r2) | |
173 | ||
174 | .Lloop64: | |
175 | vl %v16,0(%r5,%r3) /* Load s. */ | |
176 | vfenezbs %v17,%v16,%v16 /* Find element not equal with zero search. */ | |
177 | je .Lfound_v16 /* Jump away if zero was found. */ | |
178 | vl %v18,16(%r5,%r3) /* Load next part of s. */ | |
179 | vst %v16,0(%r5,%r2) /* Store previous part without zero to dst. */ | |
180 | vfenezbs %v17,%v18,%v18 | |
181 | je .Lfound_v18_16 | |
182 | vl %v16,32(%r5,%r3) | |
183 | vst %v18,16(%r5,%r2) | |
184 | vfenezbs %v17,%v16,%v16 | |
185 | je .Lfound_v16_32 | |
186 | vl %v18,48(%r5,%r3) | |
187 | vst %v16,32(%r5,%r2) | |
188 | vfenezbs %v17,%v18,%v18 | |
189 | je .Lfound_v18_48 | |
190 | vst %v18,48(%r5,%r2) | |
191 | ||
192 | aghi %r5,64 | |
193 | lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */ | |
194 | aghi %r1,64 | |
195 | clgrjl %r1,%r4,.Lloop64 | |
196 | ||
197 | vl %v16,0(%r5,%r3) /* Load s. */ | |
198 | j .Llt64 | |
d1bdbf38 | 199 | END(STRNCPY_Z13) |
d183b96e | 200 | |
d1bdbf38 SL |
201 | # if ! HAVE_STRNCPY_IFUNC |
202 | strong_alias (STRNCPY_Z13, strncpy) | |
203 | # endif | |
d183b96e | 204 | |
d1bdbf38 SL |
205 | # if ! HAVE_STRNCPY_Z900_G5 && defined SHARED && IS_IN (libc) |
206 | strong_alias (STRNCPY_Z13, __GI_strncpy) | |
207 | # endif | |
208 | #endif |