Re: [cfg-branch] unroll-new cleanups

[Zdenek Dvorak <rakdver at atrey dot karlin dot mff dot cuni dot cz>]

Hello.

> I guess we can now add support for unsigned conditionals and different strides.
> I don't see anything different on unsigned condtionals now, except that the
> bounds check conditionals I added to the code should be unsigned as well.
> Do you see some problem with these?
> 
> As this is nasty issue, I don't want to get it overhelmly complicated, so any
> hints are welcome :)

The problems might arise when using unsigned comparison on signed values (can
it happen?). I'm not sure whether conversion from signed to unsigned integers
must yield same results on different architectures? (Not that we didn't have
the same problem now when using signed comparison on unsigned values...)

Counting number of iterations with under/overflow may be a small bit nastier
than what we do now, but probably not that much. In fact, if we ignore things
like

 for (u=15;u>0;u++)

(as we do in signed case anyway), there should not be great problems with this.

Zdenek