1 /*
2 * Copyright (C) 2019 The Android Open Source Project
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 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #pragma once
30
31 #include <stdint.h>
32
33 #include <utility>
34
35 #if defined(__arm__) || defined(__aarch64__)
36 #define USE_GNU_HASH_NEON 1
37 #else
38 #define USE_GNU_HASH_NEON 0
39 #endif
40
41 #if USE_GNU_HASH_NEON
42 #include "arch/arm_neon/linker_gnu_hash_neon.h"
43 #endif
44
45 __attribute__((unused))
calculate_gnu_hash_simple(const char * name)46 static std::pair<uint32_t, uint32_t> calculate_gnu_hash_simple(const char* name) {
47 uint32_t h = 5381;
48 const uint8_t* name_bytes = reinterpret_cast<const uint8_t*>(name);
49 #pragma unroll 8
50 while (*name_bytes != 0) {
51 h += (h << 5) + *name_bytes++; // h*33 + c = h + h * 32 + c = h + h << 5 + c
52 }
53 return { h, reinterpret_cast<const char*>(name_bytes) - name };
54 }
55
calculate_gnu_hash(const char * name)56 static inline std::pair<uint32_t, uint32_t> calculate_gnu_hash(const char* name) {
57 #if USE_GNU_HASH_NEON
58 return calculate_gnu_hash_neon(name);
59 #else
60 return calculate_gnu_hash_simple(name);
61 #endif
62 }
63