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Diffstat (limited to 'libbb')
-rw-r--r--libbb/crc32.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/libbb/crc32.c b/libbb/crc32.c
index 520b1ffb9..2cc6ea779 100644
--- a/libbb/crc32.c
+++ b/libbb/crc32.c
@@ -18,6 +18,8 @@
18 18
19#include "libbb.h" 19#include "libbb.h"
20 20
21uint32_t *global_crc32_table;
22
21uint32_t* FAST_FUNC crc32_filltable(uint32_t *crc_table, int endian) 23uint32_t* FAST_FUNC crc32_filltable(uint32_t *crc_table, int endian)
22{ 24{
23 uint32_t polynomial = endian ? 0x04c11db7 : 0xedb88320; 25 uint32_t polynomial = endian ? 0x04c11db7 : 0xedb88320;
@@ -40,3 +42,25 @@ uint32_t* FAST_FUNC crc32_filltable(uint32_t *crc_table, int endian)
40 42
41 return crc_table - 256; 43 return crc_table - 256;
42} 44}
45
46uint32_t FAST_FUNC crc32_block_endian1(uint32_t val, const void *buf, unsigned len, uint32_t *crc_table)
47{
48 const void *end = (uint8_t*)buf + len;
49
50 while (buf != end) {
51 val = (val << 8) ^ crc_table[(val >> 24) ^ *(uint8_t*)buf];
52 buf = (uint8_t*)buf + 1;
53 }
54 return val;
55}
56
57uint32_t FAST_FUNC crc32_block_endian0(uint32_t val, const void *buf, unsigned len, uint32_t *crc_table)
58{
59 const void *end = (uint8_t*)buf + len;
60
61 while (buf != end) {
62 val = crc_table [(uint8_t)val ^ *(uint8_t*)buf] ^ (val >> 8);
63 buf = (uint8_t*)buf + 1;
64 }
65 return val;
66}