-fssa kicks butt on alphaev6 ieee floating point code

[Brad Lucier]

> 
> On Thu, Mar 16, 2000 at 10:43:23AM -0500, Brad Lucier wrote:
> > -fssa definitely helps IEEE floating-point register allocation on
> > alphaev6.  
> 
> It's an accident.  What it means is that our register allocator
> really bites.

I disagree completely.  

The register allocator cannot deal well with the constraint
that a source operand cannot overlap a destination operand.
Translating the intermediate representation to a canonical
form (which is what translating to SSA and back again does)
to help the register allocator in this case seems a perfectly
reasonable strategy.  (Which is why I thought of trying this
in the first place.)

Brad