David Kastrup, Sun, Oct 07, 2007 18:27:15 +0200:
> Alex Riesen <raa.lkml@xxxxxxxxx> writes:
> >> > +static inline int strbuf_cmp(const struct strbuf *a, const struct strbuf *b)
> >> > +{
> >> > + int len = a->len < b->len ? a->len: b->len;
> >> > + int cmp = memcmp(a->buf, b->buf, len);
> >> > + if (cmp)
> >> > + return cmp;
> >> > + return a->len < b->len ? -1: a->len != b->len;
> >> > +}
> >>
> >> My guess is that you are conflating two issues about speed here: the
> >> inlining will like speed the stuff up. But having to evaluate the
> >> (a->len < b->len) comparison twice will likely slow it down.
> >
> > Can't the result of the expression be reused in compiled?
> > Isn't it a common expression?
>
> No, since the call to memcmp might change a->len or b->len. A
Huh?! How's that? It is not even given them!
-
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
