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>

1 files changed, 3 insertions, 4 deletions

diff --git a/include/libbb.h b/include/libbb.h
index d14728ed0..587a5f952 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -1543,11 +1543,10 @@ void sha512_begin(sha512_ctx_t *ctx) FAST_FUNC;
 void sha512_hash(sha512_ctx_t *ctx, const void *buffer, size_t len) FAST_FUNC;
 void sha512_end(sha512_ctx_t *ctx, void *resbuf) FAST_FUNC;
 
-/* TODO: add global crc32_table pointer and create
- * LE and BE functions to calculate crc32 over given bytes.
- * Currently we have about five reimplementations...
- */
+extern uint32_t *global_crc32_table;
 uint32_t *crc32_filltable(uint32_t *tbl256, int endian) FAST_FUNC;
+uint32_t crc32_block_endian1(uint32_t val, const void *buf, unsigned len, uint32_t *crc_table) FAST_FUNC;
+uint32_t crc32_block_endian0(uint32_t val, const void *buf, unsigned len, uint32_t *crc_table) FAST_FUNC;
 
 typedef struct masks_labels_t {
         const char *labels;