[LLVMdev] Greedy register allocation

[David A. Greene]

Jakob Stoklund Olesen <stoklund at 2pi.dk> writes:

> On May 3, 2011, at 12:03 PM, David A. Greene wrote:

>> Certainly.  I would ask that we keep linearscan around, if possible, as
>> long as there are significant regressions like this.  Our customers tend
>> to really, really care about performance.
>
> That's reasonable, and it is also useful to keep it around as a reference when greedy breaks.
>
> On the other hand, I really want to clean up the code surrounding
> register allocation, and that is much easier to do after linear scan
> is gone. There is a good chance it won't make it to the 3.0 release.

Believe me, I understand the desire to clean this code up.  What's
particular about linearscan in this regard?  What parts are hard to
clean up due to linearscan?

                                  -Dave