From 9ce642f9746dfc29d119d0680b769677e3ea6da6 Mon Sep 17 00:00:00 2001
From: Denys Vlasenko <dvlasenk@redhat.com>
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 <dvlasenk@redhat.com>
---
libbb/crc32.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
(limited to 'libbb')
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;
+}
--
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