[PATCH] Don't duplicate BARRIER after tablejump in cfglayout bb header or footer (PR rtl-optimization/46777)

[Paolo Bonzini]

On 12/06/2010 07:38 PM, Jakub Jelinek wrote:
> Hi!
>
> The following testcase ICEs, because a BB has a tablejump followed
> by BARRIER in its il.rtl->header, and during unrolling duplicate_insn_chain
> doesn't (intentionally) duplicate the tablejump, but does duplicate
> the BARRIER into a header of many bbs, which breaks out of cfglayout
> pass.
>
> Fixed by not duplicating the corresponding BARRIER either.

I'm even more convinced that dropping (and eventually outlawing) 
BARRIERs in cfglayout mode would be a good idea...

Paolo