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, 5 insertions, 11 deletions

diff --git a/archival/gzip.c b/archival/gzip.c
index 32528d96b..4d399063d 100644
--- a/archival/gzip.c
+++ b/archival/gzip.c
@@ -340,7 +340,7 @@ struct globals {
         ulg bits_sent;                  /* bit length of the compressed data */
 #endif
 
-        uint32_t *crc_32_tab;
+        /*uint32_t *crc_32_tab;*/
         uint32_t crc;   /* shift register contents */
 };
 
@@ -393,15 +393,9 @@ static void put_32bit(ulg n)
  * pointer, then initialize the crc shift register contents instead.
  * Return the current crc in either case.
  */
-static uint32_t updcrc(uch * s, unsigned n)
+static void updcrc(uch * s, unsigned n)
 {
-        uint32_t c = G1.crc;
-        while (n) {
-                c = G1.crc_32_tab[(uch)(c ^ *s++)] ^ (c >> 8);
-                n--;
-        }
-        G1.crc = c;
-        return c;
+        G1.crc = crc32_block_endian0(G1.crc, s, n, global_crc32_table /*G1.crc_32_tab*/);
 }
 
 
@@ -2104,8 +2098,8 @@ int gzip_main(int argc UNUSED_PARAM, char **argv)
         ALLOC(uch, G1.window, 2L * WSIZE);
         ALLOC(ush, G1.prev, 1L << BITS);
 
-        /* Initialise the CRC32 table */
-        G1.crc_32_tab = crc32_filltable(NULL, 0);
+        /* Initialize the CRC32 table */
+        global_crc32_table = crc32_filltable(NULL, 0);
 
         return bbunpack(argv, pack_gzip, append_ext, "gz");
 }