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, 6 insertions, 16 deletions

diff --git a/archival/lzop.c b/archival/lzop.c
index c6e718ad7..acb34fe14 100644
--- a/archival/lzop.c
+++ b/archival/lzop.c
@@ -393,7 +393,7 @@ typedef struct header_t {
 } header_t;
 
 struct globals {
-        const uint32_t *lzo_crc32_table;
+        /*const uint32_t *lzo_crc32_table;*/
         chksum_t chksum_in;
         chksum_t chksum_out;
 } FIX_ALIASING;
@@ -468,19 +468,10 @@ lzo_adler32(uint32_t adler, const uint8_t* buf, unsigned len)
 static FAST_FUNC uint32_t
 lzo_crc32(uint32_t c, const uint8_t* buf, unsigned len)
 {
-        uint32_t crc;
+        //if (buf == NULL) - impossible
+        //      return 0;
 
-        if (buf == NULL)
-                return 0;
-
-        crc = ~c;
-        if (len != 0) do {
-                crc = G.lzo_crc32_table[(uint8_t)((int)crc ^ *buf)] ^ (crc >> 8);
-                buf += 1;
-                len -= 1;
-        } while (len > 0);
-
-        return ~crc;
+        return ~crc32_block_endian0(~c, buf, len, global_crc32_table);
 }
 
 /**********************************************************************/
@@ -679,8 +670,7 @@ static NOINLINE smallint lzo_compress(const header_t *h)
                 if (dst_len < src_len) {
                         /* write checksum of compressed block */
                         if (h->flags & F_ADLER32_C)
-                                write32(lzo_adler32(ADLER32_INIT_VALUE, b2,
-                                                        dst_len));
+                                write32(lzo_adler32(ADLER32_INIT_VALUE, b2, dst_len));
                         if (h->flags & F_CRC32_C)
                                 write32(lzo_crc32(CRC32_INIT_VALUE, b2, dst_len));
                         /* write compressed block data */
@@ -1080,6 +1070,6 @@ int lzop_main(int argc UNUSED_PARAM, char **argv)
         if (applet_name[0] == 'u')
                 option_mask32 |= OPT_DECOMPRESS;
 
-        G.lzo_crc32_table = crc32_filltable(NULL, 0);
+        global_crc32_table = crc32_filltable(NULL, 0);
         return bbunpack(argv, pack_lzop, make_new_name_lzop, /*unused:*/ NULL);
 }