A latent bug - use of BRANCH_EDGE on trees.

[Zdenek Dvorak]

Hello,

> I was just scratching my head for the same reason.  If I change
> BRANCH_EDGE, I would have to change FALLTHRU_EDGE to be complete.  But
> then tree dump would look confusing; when the true arm appears to
> falls through in tree dump, we don't have EDGE_FALLTHRU_FLAG.
> 
> Let's go with Zdenek's first suggestion.
> 
>   Let the caller pass the edge corresponding to the current
>   BRANCH_EDGE (switch_bb) to loopify
> 
> By the way, tree_ssa_loop_version uses FALLTHRU_EDGE, so I guess I
> have to fix that.

may be; I did not write that function, so I am not quite sure whether
this is there by mistake or on purpose.  Devang?

Zdenek