1 | /* ----------------------------------------------------------------------- * |
2 | * |
3 | * Copyright 2017 The NASM Authors - All Rights Reserved |
4 | * See the file AUTHORS included with the NASM distribution for |
5 | * the specific copyright holders. |
6 | * |
7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following |
9 | * conditions are met: |
10 | * |
11 | * * Redistributions of source code must retain the above copyright |
12 | * notice, this list of conditions and the following disclaimer. |
13 | * * Redistributions in binary form must reproduce the above |
14 | * copyright notice, this list of conditions and the following |
15 | * disclaimer in the documentation and/or other materials provided |
16 | * with the distribution. |
17 | * |
18 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND |
19 | * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
20 | * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
21 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
22 | * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
23 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
24 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
25 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
26 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
27 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
28 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
29 | * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, |
30 | * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
31 | * |
32 | * ----------------------------------------------------------------------- */ |
33 | |
34 | #include "perfhash.h" |
35 | #include "hashtbl.h" /* For crc64i() */ |
36 | |
37 | int perfhash_find(const struct perfect_hash *hash, const char *str) |
38 | { |
39 | uint32_t k1, k2; |
40 | uint64_t crc; |
41 | uint16_t ix; |
42 | |
43 | crc = crc64i(hash->crcinit, str); |
44 | k1 = (uint32_t)crc & hash->hashmask; |
45 | k2 = (uint32_t)(crc >> 32) & hash->hashmask; |
46 | |
47 | ix = hash->hashvals[k1] + hash->hashvals[k2 + hash->hashmask + 1]; |
48 | |
49 | if (ix >= hash->tbllen || |
50 | !hash->strings[ix] || |
51 | nasm_stricmp(str, hash->strings[ix])) |
52 | return hash->errval; |
53 | |
54 | return hash->tbloffs + ix; |
55 | } |
56 | |