Re: CVS commit: src/sys/dev/ic

[Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>]

> > > Eh ???
> > >     if (foo) bar(); else baz();
> > > will probably execute faster than:
> > >     (*bar_baz)();
> > > since the indirect jump is (IIRC) always unpredicted.
> > 
> > What do you have to predict on unconditional branches?
> 
> The branch destination. E.g. the CPU can't start prefetching from the
> bar().

Probably you guys should check diffs first:
+       if (sc->write_mbuf == NULL)
+               sc->write_mbuf = dp8390_write_mbuf;
 :
-       if (sc->write_mbuf)
-               len = (*sc->write_mbuf)(sc, m0, buffer);
-       else
-               len = dp8390_write_mbuf(sc, m0, buffer);
+       len = (*sc->write_mbuf)(sc, m0, buffer);

i.e.
+       if (!foo) foo = bar;
 :
-       if (foo) (*foo)() else inlined_bar()
+       (*foo)()
Few (no?) drivers use the latter inlined one
so no befefit of prefetch with predict.
---
Izumi Tsutsui