1/*
2 * Copyright (c) 1993,94 Winning Strategies, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by Winning Strategies, Inc.
16 * 4. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <machine/asm.h>
| 1/*
2 * Copyright (c) 1993,94 Winning Strategies, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by Winning Strategies, Inc.
16 * 4. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <machine/asm.h>
|
33
34/*
35 * strncmp(s1, s2, n)
36 * return an integer greater than, equal to, or less than 0,
37 * according as the first n characters of string s1 is greater
38 * than, equal to, or less than the string s2.
39 *
40 * %eax - pointer to s1
41 * %ecx - pointer to s2
42 * %edx - length
43 *
44 * Written by:
45 * J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
46 */
47
48/*
49 * I've unrolled the loop eight times: large enough to make a
50 * significant difference, and small enough not to totally trash the
51 * cache.
52 *
53 * TODO: change all the jz's back to je for consistency.
54 */
55
56ENTRY(strncmp)
57 pushl %ebx
58 movl 8(%esp),%eax
59 movl 12(%esp),%ecx
60 movl 16(%esp),%edx
61 testl %edx,%edx
62 jmp L2 /* Jump into the loop! */
63
64 .align 2,0x90
65L1: incl %eax
66 incl %ecx
67 decl %edx
68L2: jz L4 /* strings are equal */
69 movb (%eax),%bl
70 testb %bl,%bl
71 jz L3
72 cmpb %bl,(%ecx)
73 jne L3
74
75/*
76 * XXX it might be best to move the next 4 instructions to the end of the
77 * unrolled part of the loop. The unrolled part would then be
78 * movb n(%eax),%bl; testb %bl, %bl; je L3; cmpb n(%ecx); jne L3
79 * or maybe better
80 * movb n(%eax),%bl; cmpb n(%ecx); jne L3; testb %bl,%bl; je return_0
81 * for n = 0, 1, ..., 8. The end of the loop would be
82 * L1: addl $8,%eax; addl $8,%ecx; subl $8,%edx; cmpl $8,%edx; jae Lx
83 * where residual counts of 0 to 7 are handled at Lx. However, this would
84 * be slower for short strings. Cache effects are probably not so
85 * important because we are only handling a byte at a time.
86 */
87 incl %eax
88 incl %ecx
89 decl %edx
90 jz L4
91 movb (%eax),%bl
92 testb %bl,%bl
93 jz L3
94 cmpb %bl,(%ecx)
95 jne L3
96
97 incl %eax
98 incl %ecx
99 decl %edx
100 jz L4
101 movb (%eax),%bl
102 testb %bl,%bl
103 jz L3
104 cmpb %bl,(%ecx)
105 jne L3
106
107 incl %eax
108 incl %ecx
109 decl %edx
110 jz L4
111 movb (%eax),%bl
112 testb %bl,%bl
113 jz L3
114 cmpb %bl,(%ecx)
115 jne L3
116
117 incl %eax
118 incl %ecx
119 decl %edx
120 jz L4
121 movb (%eax),%bl
122 testb %bl,%bl
123 jz L3
124 cmpb %bl,(%ecx)
125 jne L3
126
127 incl %eax
128 incl %ecx
129 decl %edx
130 jz L4
131 movb (%eax),%bl
132 testb %bl,%bl
133 jz L3
134 cmpb %bl,(%ecx)
135 jne L3
136
137 incl %eax
138 incl %ecx
139 decl %edx
140 jz L4
141 movb (%eax),%bl
142 testb %bl,%bl
143 jz L3
144 cmpb %bl,(%ecx)
145 jne L3
146
147 incl %eax
148 incl %ecx
149 decl %edx
150 jz L4
151 movb (%eax),%bl
152 testb %bl,%bl
153 jz L3
154 cmpb %bl,(%ecx)
155 je L1
156
157 .align 2,0x90
158L3: movzbl (%eax),%eax /* unsigned comparison */
159 movzbl (%ecx),%ecx
160 subl %ecx,%eax
161 popl %ebx
162 ret
163 .align 2,0x90
164L4: xorl %eax,%eax
165 popl %ebx
166 ret
| 33
34/*
35 * strncmp(s1, s2, n)
36 * return an integer greater than, equal to, or less than 0,
37 * according as the first n characters of string s1 is greater
38 * than, equal to, or less than the string s2.
39 *
40 * %eax - pointer to s1
41 * %ecx - pointer to s2
42 * %edx - length
43 *
44 * Written by:
45 * J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
46 */
47
48/*
49 * I've unrolled the loop eight times: large enough to make a
50 * significant difference, and small enough not to totally trash the
51 * cache.
52 *
53 * TODO: change all the jz's back to je for consistency.
54 */
55
56ENTRY(strncmp)
57 pushl %ebx
58 movl 8(%esp),%eax
59 movl 12(%esp),%ecx
60 movl 16(%esp),%edx
61 testl %edx,%edx
62 jmp L2 /* Jump into the loop! */
63
64 .align 2,0x90
65L1: incl %eax
66 incl %ecx
67 decl %edx
68L2: jz L4 /* strings are equal */
69 movb (%eax),%bl
70 testb %bl,%bl
71 jz L3
72 cmpb %bl,(%ecx)
73 jne L3
74
75/*
76 * XXX it might be best to move the next 4 instructions to the end of the
77 * unrolled part of the loop. The unrolled part would then be
78 * movb n(%eax),%bl; testb %bl, %bl; je L3; cmpb n(%ecx); jne L3
79 * or maybe better
80 * movb n(%eax),%bl; cmpb n(%ecx); jne L3; testb %bl,%bl; je return_0
81 * for n = 0, 1, ..., 8. The end of the loop would be
82 * L1: addl $8,%eax; addl $8,%ecx; subl $8,%edx; cmpl $8,%edx; jae Lx
83 * where residual counts of 0 to 7 are handled at Lx. However, this would
84 * be slower for short strings. Cache effects are probably not so
85 * important because we are only handling a byte at a time.
86 */
87 incl %eax
88 incl %ecx
89 decl %edx
90 jz L4
91 movb (%eax),%bl
92 testb %bl,%bl
93 jz L3
94 cmpb %bl,(%ecx)
95 jne L3
96
97 incl %eax
98 incl %ecx
99 decl %edx
100 jz L4
101 movb (%eax),%bl
102 testb %bl,%bl
103 jz L3
104 cmpb %bl,(%ecx)
105 jne L3
106
107 incl %eax
108 incl %ecx
109 decl %edx
110 jz L4
111 movb (%eax),%bl
112 testb %bl,%bl
113 jz L3
114 cmpb %bl,(%ecx)
115 jne L3
116
117 incl %eax
118 incl %ecx
119 decl %edx
120 jz L4
121 movb (%eax),%bl
122 testb %bl,%bl
123 jz L3
124 cmpb %bl,(%ecx)
125 jne L3
126
127 incl %eax
128 incl %ecx
129 decl %edx
130 jz L4
131 movb (%eax),%bl
132 testb %bl,%bl
133 jz L3
134 cmpb %bl,(%ecx)
135 jne L3
136
137 incl %eax
138 incl %ecx
139 decl %edx
140 jz L4
141 movb (%eax),%bl
142 testb %bl,%bl
143 jz L3
144 cmpb %bl,(%ecx)
145 jne L3
146
147 incl %eax
148 incl %ecx
149 decl %edx
150 jz L4
151 movb (%eax),%bl
152 testb %bl,%bl
153 jz L3
154 cmpb %bl,(%ecx)
155 je L1
156
157 .align 2,0x90
158L3: movzbl (%eax),%eax /* unsigned comparison */
159 movzbl (%ecx),%ecx
160 subl %ecx,%eax
161 popl %ebx
162 ret
163 .align 2,0x90
164L4: xorl %eax,%eax
165 popl %ebx
166 ret
|