Dropping of old loop optimizer

[Jan Hubicka]

> 
> On Thursday, February 27, 2003, at 12:13  PM, Pop SĂŠbastian wrote:
> 
> >On Thu, Feb 27, 2003 at 05:39:17PM +0100, Zdenek Dvorak wrote:
> >>
> >>The problem I see is that rtl ssa is broken (or never worked?); but
> >Last time I had a close look at rtl was about two years ago :-)
> >Dan is the expert to ask about the status of SSA at rtl level (he 
> >adapted
> >the CCP code from rtl to tree-ssa).
> The problem with RTL SSA is hard registers and subregs.
> There are hard registers assigned in certain cases during initial RTL 
> generation.
> These can't be renamed, obviously.

The tree-SSA represents the SSA form as datastructure on the top of the
trees not modifying the trees themselves, right?  Why it is not feasible
for RTL (ie you won't need to rename the registers)

Honza