| blob | 20dd6a9deba6b4f4f2689c02da6db1cedab9c2ff |
1 /* Compare two strings for differences.
2 For SPARC v7.
3 Copyright (C) 1996-2013 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5 Contributed by Jakub Jelinek <jj@ultra.linux.cz>.
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Lesser General Public
9 License as published by the Free Software Foundation; either
10 version 2.1 of the License, or (at your option) any later version.
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
17 You should have received a copy of the GNU Lesser General Public
18 License along with the GNU C Library; if not, see
19 <http://www.gnu.org/licenses/>. */
21 #include <sysdep.h>
23 /* Normally, this uses ((xword - 0x01010101) & 0x80808080) test
24 to find out if any byte in xword could be zero. This is fast, but
25 also gives false alarm for any byte in range 0x81-0xff. It does
26 not matter for correctness, as if this test tells us there could
27 be some zero byte, we check it byte by byte, but if bytes with
28 high bits set are common in the strings, then this will give poor
29 performance. You can #define EIGHTBIT_NOT_RARE and the algorithm
30 will use one tick slower, but more precise test
31 ((xword - 0x01010101) & (~xword) & 0x80808080),
32 which does not give any false alarms (but if some bits are set,
33 one cannot assume from it which bytes are zero and which are not).
34 It is yet to be measured, what is the correct default for glibc
35 in these days for an average user.
36 */
38 .text
39 .align 4
41 ENTRY(strcmp)
42 andcc %o0, 3, %g0
43 be 13f
44 sethi %hi(0x80808080), %g1
46 ldub [%o0], %o4
47 add %o0, 1, %o0
48 ldub [%o1], %o5
49 cmp %o4, 0
50 add %o1, 1, %o1
51 be 2f
52 subcc %o4, %o5, %o4
53 bne 2f
54 andcc %o0, 3, %g0
55 be 4f
56 or %g1, %lo(0x80808080), %o3
57 ldub [%o0], %o4
58 add %o0, 1, %o0
59 ldub [%o1], %o5
60 cmp %o4, 0
61 add %o1, 1, %o1
62 be 2f
63 subcc %o4, %o5, %o4
64 bne 2f
65 andcc %o0, 3, %g0
66 be 5f
67 sethi %hi(0x01010101), %g1
68 ldub [%o0], %o4
69 add %o0, 1, %o0
70 ldub [%o1], %o5
71 cmp %o4, 0
72 add %o1, 1, %o1
73 be 2f
74 subcc %o4, %o5, %o4
75 bne 2f
76 andcc %o1, 3, %g2
77 bne 12f
78 or %g1, %lo(0x01010101), %o2
79 b 1f
80 ld [%o0], %o4
81 2: retl
82 mov %o4, %o0
84 13: or %g1, %lo(0x80808080), %o3
85 4: sethi %hi(0x01010101), %g1
86 5: andcc %o1, 3, %g2
87 bne 12f
88 or %g1, %lo(0x01010101), %o2
90 0: ld [%o0], %o4
91 1: ld [%o1], %o5
92 sub %o4, %o2, %g1
93 add %o0, 4, %o0
94 cmp %o4, %o5
95 #ifdef EIGHTBIT_NOT_RARE
96 andn %g1, %o4, %g1
97 #endif
98 bne 11f
99 andcc %g1, %o3, %g0
100 be 0b
101 add %o1, 4, %o1
103 srl %o4, 24, %g4
104 andcc %g4, 0xff, %g0
105 be 2f
106 srl %o4, 16, %g4
107 andcc %g4, 0xff, %g0
108 be 2f
109 srl %o4, 8, %g4
110 andcc %g4, 0xff, %g0
111 be 2f
112 andcc %o4, 0xff, %g0
113 bne,a 1b
114 ld [%o0], %o4
115 2: retl
116 clr %o0
118 11: srl %o4, 24, %g4
119 srl %o5, 24, %g5
120 andcc %g4, 0xff, %g0
121 be 3f
122 subcc %g4, %g5, %g4
123 bne 3f
124 srl %o5, 16, %g5
125 srl %o4, 16, %g4
126 andcc %g4, 0xff, %g0
127 be 3f
128 subcc %g4, %g5, %g4
129 bne 3f
130 srl %o5, 8, %g5
131 srl %o4, 8, %g4
132 andcc %g4, 0xff, %g0
133 be 3f
134 subcc %g4, %g5, %g4
135 bne 3f
136 subcc %o4, %o5, %o4
137 retl
138 mov %o4, %o0
139 3: retl
140 mov %g4, %o0
142 12: save %sp, -64, %sp
143 ld [%i0], %i4
144 sll %g2, 3, %g3
145 andn %i1, 3, %i1
146 mov 32, %l1
147 ld [%i1], %l2
148 mov -1, %g6
149 add %i1, 4, %i1
150 sub %l1, %g3, %l1
151 sll %g6, %g3, %g6
153 1: sll %l2, %g3, %g5
154 and %i4, %g6, %l3
155 sub %i4, %i2, %g1
156 #ifdef EIGHTBIT_NOT_RARE
157 andn %g1, %i4, %g1
158 #endif
159 andcc %g1, %i3, %g1
160 bne 3f
161 cmp %g5, %l3
162 bne 2f
163 add %i0, 4, %i0
164 ld [%i1], %l2
165 add %i1, 4, %i1
166 srl %l2, %l1, %l4
167 or %l4, %g5, %l4
168 cmp %l4, %i4
169 be,a 1b
170 ld [%i0], %i4
171 restore %l4, %g0, %o3
172 retl
173 sub %o4, %o3, %o0
175 2: sll %l2, %g3, %i2
176 srl %i4, %g3, %i3
177 srl %i2, %g3, %i2
178 restore
179 retl
180 sub %o3, %o2, %o0
182 3: srl %i4, 24, %g4
183 srl %g5, 24, %l6
184 andcc %g4, 0xff, %g0
185 be 4f
186 subcc %g4, %l6, %g4
187 bne 4f
188 cmp %g2, 3
189 be 6f
190 srl %i4, 16, %g4
191 srl %g5, 16, %l6
192 andcc %g4, 0xff, %g0
193 be 4f
194 subcc %g4, %l6, %g4
195 bne 4f
196 cmp %g2, 2
197 be 5f
198 srl %i4, 8, %g4
199 srl %g5, 8, %l6
200 andcc %g4, 0xff, %g0
201 be 4f
202 subcc %g4, %l6, %g4
203 bne 4f
204 add %i0, 4, %i0
205 ld [%i1], %l2
206 add %i1, 4, %i1
207 srl %l2, 24, %g5
208 andcc %i4, 0xff, %g4
209 be 4f
210 subcc %g4, %g5, %g4
211 be,a 1b
212 ld [%i0], %i4
213 4: jmpl %i7 + 8, %g0
214 restore %g4, %g0, %o0
216 5: ld [%i1], %l2
217 add %i1, 4, %i1
218 add %i0, 4, %i0
219 srl %l2, 24, %l6
220 andcc %g4, 0xff, %g4
221 be 4b
222 subcc %g4, %l6, %g4
223 bne 4b
224 srl %l2, 16, %l6
225 andcc %i4, 0xff, %g4
226 and %l6, 0xff, %l6
227 be 4b
228 subcc %g4, %l6, %g4
229 be,a 1b
230 ld [%i0], %i4
231 jmpl %i7 + 8, %g0
232 restore %g4, %g0, %o0
234 6: ld [%i1], %l2
235 add %i1, 4, %i1
236 add %i0, 4, %i0
237 srl %l2, 24, %l6
238 andcc %g4, 0xff, %g4
239 be 4b
240 subcc %g4, %l6, %g4
241 bne 4b
242 srl %l2, 16, %l6
243 srl %i4, 8, %g4
244 and %l6, 0xff, %l6
245 andcc %g4, 0xff, %g4
246 be 4b
247 subcc %g4, %l6, %g4
248 bne 4b
249 srl %l2, 8, %l6
250 andcc %i4, 0xff, %g4
251 and %l6, 0xff, %l6
252 be 4b
253 subcc %g4, %l6, %g4
254 be,a 1b
255 ld [%i0], %i4
256 jmpl %i7 + 8, %g0
257 restore %g4, %g0, %o0
258 END(strcmp)
259 libc_hidden_builtin_def (strcmp)