Ulrich Spörlein <u...@spoerlein.net> writes:
> optimizing compilers have a tendency to remove assignments that have
> no side effects. The code in sys/crypto/sha2/sha2.c is doing a lot of
> zeroing variables, which is however optimized away. [...] Is there a
> canonical way to zero those variables and should we use them (memset
> perhaps? what are the performance implications?)
If you stick these variables in a struct, you can memset the struct to
zero them; if there are many of them, it may be faster than zeroing them
individually.
Alternatively, you can use something like this:
#define FORCE_ASSIGN(type, var, value) \
*(volatile type *)&(var) = (value)
DES
--
Dag-Erling Smørgrav - d...@des.no
_______________________________________________
freebsd-current@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-current
To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
