Flow analysis and optimization with computed gotos

[Brad Lucier]

Michael Matz wrote:
> It still isn't correct though. E.g. if the expression didn't come from the
> destination block. The real solution is, that abnormal critical edges
> (s->d) kill all expressions from which it's not provable that they don't
> trap in block d.

For many of these large routines, gcse is disabled because
the number of basic blocks is > 1000 and the number of edges/basic
block is >= 20.  In these cases I'd be happier if these abnormal
critical edges were just ignored, if that would be possible, and gcse
performed on the subgraphs that do not involve these edges; if
we agreed that abnormal critical edges killed *all* expressions across
them, could they be ignored for purposes of gcse?

Brad