On Wed, Jan 31, 2018 at 11:03:04AM -0800, William Tu wrote:
> The offsetof(struct ovs_router_entry, cr) should always be 0,
> thus the else statement should never be reached.
>
> Signed-off-by: William Tu <[email protected]>
> ---
> lib/ovs-router.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/lib/ovs-router.c b/lib/ovs-router.c
> index cd2ab15fb003..bc8616858a84 100644
> --- a/lib/ovs-router.c
> +++ b/lib/ovs-router.c
> @@ -71,7 +71,7 @@ ovs_router_entry_cast(const struct cls_rule *cr)
> if (offsetof(struct ovs_router_entry, cr) == 0) {
> return CONTAINER_OF(cr, struct ovs_router_entry, cr);
> } else {
> - return cr ? CONTAINER_OF(cr, struct ovs_router_entry, cr) : NULL;
> + OVS_NOT_REACHED();
> }
> }
This code seems odd, I would prefer to just write the general-purpose
code and skip the microoptimizations, like this:
struct ovs_router_entry *
ovs_router_entry_cast(const struct cls_rule *cr)
{
return cr ? CONTAINER_OF(cr, struct ovs_router_entry, cr) : NULL;
}
GCC optimizes it properly anyhow, in all three versions:
(gdb) disass ovs_router_entry_cast
Dump of assembler code for function ovs_router_entry_cast:
0x00000e30 <+0>: mov 0x4(%esp),%eax
0x00000e34 <+4>: ret
End of assembler dump.
_______________________________________________
dev mailing list
[email protected]
https://mail.openvswitch.org/mailman/listinfo/ovs-dev
