On Wed, Jan 02, 2002 at 08:39:20AM -0700, Tom Rini wrote:
> Well, Paulus wrote 'strcpy' not 'memcpy', so why does gcc get to assume
> it's safe to change it? In this case it's certainly not.
But unless you trigger undefined behaviour, strcpy(x, "foobar" + n) is
equal to memcpy(x, "foobar" + n, sizeof("foobar") - n); and the latter is
more efficient (you don't have to check for end-of-string during copying).
> > It is not a workaround, it is a fix to an invalid code, which gets
> > triggered by particular optimization.
>
> By a particular optimization that's not present before gcc-3.0, and
> happens to break things under some conditions, as you've seen.
It just happens to do a different thing than it used to when seeing code
with particular case of undefined behaviour.
Jakub
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Mon Jan 07 2002 - 21:00:17 EST