1 | /* $NetBSD: strspn.c,v 1.1 2014/07/19 18:38:33 lneto Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 2008 Joerg Sonnenberger |
5 | * All rights reserved. |
6 | * |
7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following conditions |
9 | * are met: |
10 | * 1. Redistributions of source code must retain the above copyright |
11 | * notice, this list of conditions and the following disclaimer. |
12 | * 2. Redistributions in binary form must reproduce the above copyright |
13 | * notice, this list of conditions and the following disclaimer in the |
14 | * documentation and/or other materials provided with the distribution. |
15 | * |
16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR |
17 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
18 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
19 | * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, |
20 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
21 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
22 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
23 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
24 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
25 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
26 | */ |
27 | |
28 | #include <sys/cdefs.h> |
29 | __RCSID("$NetBSD: strspn.c,v 1.1 2014/07/19 18:38:33 lneto Exp $" ); |
30 | |
31 | #if !defined(_KERNEL) && !defined(_STANDALONE) |
32 | #include <assert.h> |
33 | #include <inttypes.h> |
34 | #include <limits.h> |
35 | #include <string.h> |
36 | #else |
37 | #include <lib/libkern/libkern.h> |
38 | #endif |
39 | |
40 | #if ULONG_MAX != 0xffffffffffffffffull |
41 | |
42 | size_t |
43 | strspn(const char *s, const char *charset) |
44 | { |
45 | static const uint8_t idx[8] = { 1, 2, 4, 8, 16, 32, 64, 128 }; |
46 | uint8_t set[32]; |
47 | const char *t; |
48 | #define UC(a) ((unsigned int)(unsigned char)(a)) |
49 | |
50 | _DIAGASSERT(s != NULL); |
51 | _DIAGASSERT(charset != NULL); |
52 | |
53 | if (charset[0] == '\0') |
54 | return 0; |
55 | if (charset[1] == '\0') { |
56 | for (t = s; *t != '\0'; ++t) { |
57 | if (*t != *charset) |
58 | break; |
59 | } |
60 | return t - s; |
61 | } |
62 | |
63 | (void)memset(set, 0, sizeof(set)); |
64 | |
65 | for (; *charset != '\0'; ++charset) |
66 | set[UC(*charset) >> 3] |= idx[UC(*charset) & 7]; |
67 | |
68 | for (t = s; *t != '\0'; ++t) |
69 | if ((set[UC(*t) >> 3] & idx[UC(*t) & 7]) == 0) |
70 | break; |
71 | return t - s; |
72 | } |
73 | |
74 | #else |
75 | |
76 | /* 64 bit system, use four 64 bits registers for bitmask */ |
77 | |
78 | static size_t |
79 | strspn_x(const char *s_s, const char *charset_s, unsigned long invert) |
80 | { |
81 | const unsigned char *s = (const unsigned char *)s_s; |
82 | const unsigned char *charset = (const unsigned char *)charset_s; |
83 | unsigned long m_0, m_4, m_8, m_c; |
84 | unsigned char ch, next_ch; |
85 | unsigned long bit; |
86 | unsigned long check; |
87 | size_t count; |
88 | |
89 | /* Four 64bit registers have one bit for each character value */ |
90 | m_0 = 0; |
91 | m_4 = 0; |
92 | m_8 = 0; |
93 | m_c = 0; |
94 | |
95 | for (ch = *charset; ch != 0; ch = next_ch) { |
96 | next_ch = *++charset; |
97 | bit = 1ul << (ch & 0x3f); |
98 | if (__predict_true(ch < 0x80)) { |
99 | if (ch < 0x40) |
100 | m_0 |= bit; |
101 | else |
102 | m_4 |= bit; |
103 | } else { |
104 | if (ch < 0xc0) |
105 | m_8 |= bit; |
106 | else |
107 | m_c |= bit; |
108 | } |
109 | } |
110 | |
111 | /* For strcspn() we just invert the validity set */ |
112 | m_0 ^= invert; |
113 | m_4 ^= invert; |
114 | m_8 ^= invert; |
115 | m_c ^= invert; |
116 | |
117 | /* |
118 | * We could do remove the lsb from m_0 to terminate at the |
119 | * end of the input string. |
120 | * However prefetching the next char is benifitial and we must |
121 | * not read the byte after the \0 - as it might fault! |
122 | * So we take the 'hit' of the compare against 0. |
123 | */ |
124 | |
125 | ch = *s++; |
126 | for (count = 0; ch != 0; ch = next_ch) { |
127 | next_ch = s[count]; |
128 | if (__predict_true(ch < 0x80)) { |
129 | check = m_0; |
130 | if (ch >= 0x40) |
131 | check = m_4; |
132 | } else { |
133 | check = m_8; |
134 | if (ch >= 0xc0) |
135 | check = m_c; |
136 | } |
137 | if (!((check >> (ch & 0x3f)) & 1)) |
138 | break; |
139 | count++; |
140 | } |
141 | return count; |
142 | } |
143 | |
144 | size_t |
145 | strspn(const char *s, const char *charset) |
146 | { |
147 | return strspn_x(s, charset, 0); |
148 | } |
149 | |
150 | size_t |
151 | strcspn(const char *s, const char *charset) |
152 | { |
153 | return strspn_x(s, charset, ~0ul); |
154 | } |
155 | #endif |
156 | |