1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
|
/* compare256.c -- 256 byte memory comparison with match length return
* Copyright (C) 2020 Nathan Moinvaziri
* For conditions of distribution and use, see copyright notice in zlib.h
*/
#include "zbuild.h"
#include "zendian.h"
#include "deflate.h"
#include "fallback_builtins.h"
/* 8-bit integer comparison for hardware without unaligned loads */
static inline uint32_t compare256_8_static(const uint8_t *src0, const uint8_t *src1) {
uint32_t len = 0;
do {
if (src0[0] != src1[0])
return len;
if (src0[1] != src1[1])
return len + 1;
if (src0[2] != src1[2])
return len + 2;
if (src0[3] != src1[3])
return len + 3;
if (src0[4] != src1[4])
return len + 4;
if (src0[5] != src1[5])
return len + 5;
if (src0[6] != src1[6])
return len + 6;
if (src0[7] != src1[7])
return len + 7;
src0 += 8, src1 += 8, len += 8;
} while (len < 256);
return 256;
}
/* 64-bit integer comparison for hardware with unaligned loads */
static inline uint32_t compare256_64_static(const uint8_t *src0, const uint8_t *src1) {
uint32_t len = 0;
do {
uint64_t sv = zng_memread_8(src0);
uint64_t mv = zng_memread_8(src1);
uint64_t diff = sv ^ mv;
if (diff)
return len + zng_ctz64(Z_U64_TO_LE(diff)) / 8;
src0 += 8, src1 += 8, len += 8;
sv = zng_memread_8(src0);
mv = zng_memread_8(src1);
diff = sv ^ mv;
if (diff)
return len + zng_ctz64(Z_U64_TO_LE(diff)) / 8;
src0 += 8, src1 += 8, len += 8;
} while (len < 256);
return 256;
}
#if OPTIMAL_CMP == 8
# define COMPARE256 compare256_8_static
#else
# define COMPARE256 compare256_64_static
#endif
#ifdef WITH_ALL_FALLBACKS
Z_INTERNAL uint32_t compare256_8(const uint8_t *src0, const uint8_t *src1) {
return compare256_8_static(src0, src1);
}
Z_INTERNAL uint32_t compare256_64(const uint8_t *src0, const uint8_t *src1) {
return compare256_64_static(src0, src1);
}
#endif
Z_INTERNAL uint32_t compare256_c(const uint8_t *src0, const uint8_t *src1) {
return COMPARE256(src0, src1);
}
// Generate longest_match_c
#define LONGEST_MATCH longest_match_c
#include "match_tpl.h"
// Generate longest_match_slow_c
#define LONGEST_MATCH_SLOW
#define LONGEST_MATCH longest_match_slow_c
#include "match_tpl.h"
|
