xdiff: avoid more compiler warnings with XDL_FAST_HASH on 32-bit machines

Hide literals that can cause compiler warnings for 32-bit architectures in
expressions that evaluate to small numbers there.  Some compilers warn that
0x0001020304050608 won't fit into a 32-bit long, others that shifting right
by 56 bits clears a 32-bit value completely.

The correct values are calculated in the 64-bit case, which is all that matters
in this if-branch.

Reported-by: Øyvind A. Holm <sunny@sunbase.org>
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Acked-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
René Scharfe 2012-05-22 22:36:39 +02:00 committed by Junio C Hamano
parent 9322ce21ee
commit 7e356a9794

View file

@ -301,7 +301,13 @@ static inline long count_masked_bytes(unsigned long mask)
* that works for the bytemasks without having to
* mask them first.
*/
return mask * 0x0001020304050608 >> 56;
/*
* return mask * 0x0001020304050608 >> 56;
*
* Doing it like this avoids warnings on 32-bit machines.
*/
long a = (REPEAT_BYTE(0x01) / 0xff + 1);
return mask * a >> (sizeof(long) * 7);
} else {
/*
* Modified Carl Chatfield G+ version for 32-bit *