io_uring: drop redundant IO_MODE_OFFLOAD check
[fio.git] / crc / fnv.c
1 #include "fnv.h"
2
3 #define FNV_PRIME       0x100000001b3ULL
4
5 /*
6  * 64-bit fnv, but don't require 64-bit multiples of data. Use bytes
7  * for the last unaligned chunk.
8  */
9 uint64_t fnv(const void *buf, uint32_t len, uint64_t hval)
10 {
11         const uint64_t *ptr = buf;
12
13         while (len) {
14                 hval *= FNV_PRIME;
15                 if (len >= sizeof(uint64_t)) {
16                         hval ^= (uint64_t) *ptr++;
17                         len -= sizeof(uint64_t);
18                         continue;
19                 } else {
20                         const uint8_t *ptr8 = (const uint8_t *) ptr;
21                         uint64_t val = 0;
22                         int i;
23
24                         for (i = 0; i < len; i++) {
25                                 val <<= 8;
26                                 val |= (uint8_t) *ptr8++;
27                         }
28                         hval ^= val;
29                         break;
30                 }
31         }
32
33         return hval;
34 }