From 9ce642f9746dfc29d119d0680b769677e3ea6da6 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Wed, 27 Oct 2010 15:26:45 +0200 Subject: libbb: introduce and use common crc32 routine function old new delta crc32_block_endian1 - 37 +37 crc32_block_endian0 - 34 +34 global_crc32_table - 8 +8 file_read 82 87 +5 gzip_main 211 214 +3 xz_crc32 40 35 -5 crc32_table 8 - -8 calculate_gunzip_crc 54 34 -20 lzo_crc32 54 25 -29 cksum_main 298 211 -87 ------------------------------------------------------------------------------ (add/remove: 3/1 grow/shrink: 2/4 up/down: 87/-149) Total: -62 bytes Signed-off-by: Denys Vlasenko --- libbb/crc32.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'libbb/crc32.c') 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 @@ #include "libbb.h" +uint32_t *global_crc32_table; + uint32_t* FAST_FUNC crc32_filltable(uint32_t *crc_table, int endian) { uint32_t polynomial = endian ? 0x04c11db7 : 0xedb88320; @@ -40,3 +42,25 @@ uint32_t* FAST_FUNC crc32_filltable(uint32_t *crc_table, int endian) return crc_table - 256; } + +uint32_t FAST_FUNC crc32_block_endian1(uint32_t val, const void *buf, unsigned len, uint32_t *crc_table) +{ + const void *end = (uint8_t*)buf + len; + + while (buf != end) { + val = (val << 8) ^ crc_table[(val >> 24) ^ *(uint8_t*)buf]; + buf = (uint8_t*)buf + 1; + } + return val; +} + +uint32_t FAST_FUNC crc32_block_endian0(uint32_t val, const void *buf, unsigned len, uint32_t *crc_table) +{ + const void *end = (uint8_t*)buf + len; + + while (buf != end) { + val = crc_table [(uint8_t)val ^ *(uint8_t*)buf] ^ (val >> 8); + buf = (uint8_t*)buf + 1; + } + return val; +} -- cgit v1.2.3