H. Peter Anvin | 5253f58 | 2017-04-03 00:09:58 -0700 | [diff] [blame] | 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 | } |