X[]==Y[] is 7X slower than it should be -- why?

[Sean Kelly]

== Quote from Sean Kelly (sean at invisibleduck.org)'s article
> == Quote from Tomas Lindquist Olsen (tomas at famolsen.dk)'s article
> > Sean Kelly wrote:
> > > == Quote from Jarrett Billingsley (kb3ctd2 at yahoo.com)'s article
> > >> "Sean Kelly" <sean at invisibleduck.org> wrote in message
> > >> news:g3gtvk$1tm7$1 at digitalmars.com...
> > >>> Done :p
> > >>>
> > >>> http://dsource.org/projects/tango/changeset/3651
> > >> In _adCmp,
> > >> if (a1.ptr == a2.ptr)
> > >>     return 0;
> > >> erm, that's not right at all.  Two slices with the same pointer and
> > >> different lengths.
> > >
> > > Darnit, you're right.  Good catch.
> > >
> > >
> > > Sean
> > After having a look at this I don't see how it could work.
> > The TypeInfo passed to _adEq/Cmp is the *element* typeinfo, not the *array*
> typeinfo.
> > With the current code, the way I read it, only arrays with elementsize==1 will
> work (and only
> > if the element is not a 1byte struct that overloads the comparison operators.
> > Am I missing something or should the compilers not be changed to pass the
> *array* typeinfo if
> > these optimizations are to make any sense ?
> I was wondering about that.  *sigh* I guess I'll have to change it back then.  How
> terribly annoying.

Hold on.  Why would that routine get the TypeInfo for the element and not the
array?  Similar typed arrays can only be compared anyway, and the differences
between static and sdynamic arrays are irrelevant for comparisons.  What am I
missing?  I'm inclined to just file a bug report asking that this be changed.


Sean