[rtl-optimization] Improve Data Prefetch for IA-64

[Zdenek Dvorak]

Hello,

> On Sunday 27 March 2005 03:53, Canqun Yang wrote:
> > The last ChangeLog of rtlopt-branch was written in
> > 2003. After more than one year, many impovements in
> > this branch haven't been put into the GCC HEAD. Why?
> 
> Almost all of the rtlopt branch was merged.  Prefetching is one
> of the few things that was not, probably Zdenek knows why.

because I never made it work as well as the current version,
basically.  At least no matter how much I tried, I never produced
any benchmark numbers that would justify the change.  Then I went
to tree-ssa (and tried to write prefetching there, and got stuck on
the same issue, after which I simply forgot due to loads of other work
:-( ).

Zdenek