Re: [tree-ssa] Block merging (updated)

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

Hello,

>  >If there really is some reason why not to remove them, we should also
>  >fix other places that cause it (jump threading, OTOH, perhaps some
>  >other).
> Certainly.  Can you point out specifics where they are being deleted?
> 
> "jump threading" is not specific enough -- we have an RTL version as
> well as a tree version.  A testcase would also be helpful.

the tree one -- when you thread over a block containing the user label,
it may become unreachable and it is then removed.  On the other hand,
having user labels prevent jump threading seems sort of stupid.

Zdenek