Re: Creating a prettier flow graph

[Richard Henderson <rth at cygnus dot com>]

On Thu, Oct 15, 1998 at 12:36:08PM +0200, Bernd Schmidt wrote:
> One issue which I forgot to mention the last time: the async_exceptions code
> is giving me headaches.  It talks about making an edge from every insn to an
> exception handler block, which is bogus as we can't really make edges from
> insns, only from basic blocks.  Does someone have a clue as to what that is
> all about?

The idea behind async_exceptions is to allow for a signal handler to
be able to throw.  It probably doesn't actually work right now.

However, the way I would think of it only affects life_analysis --
if async_exceptions, an expression live across an edge marked EDGE_EH
is not dead even if it would otherwise be killed later in the current
basic block.

Whether or not this is actually good enough to get things to work
in the presence of other optimizations, I have no idea.


r~