[tree-ssa] RFC: Making control flow more explicit

[Diego Novillo]

On Thu, 2003-08-07 at 14:45, Jason Merrill wrote:

> MWHIRL lowers all control flow to gotos, possibly conditional or computed.
> This seems to be what you're looking for.  We probably want to define a
> lower GIMPLE to match, and do the lowering somewhere in the middle of
> optimization.
> 
Right.  And this is where we are currently having conflicts.  We are
essentially doing ORC's OPT phase in HWHIRL.  The effect of exposing
more control flow would take us to MWHIRL and build the SSA form there. 
We are now building the SSA form in HWHIRL.

We probably do want to define a lower GIMPLE form.  Syntactically it
would be no different.  It would only accept fewer tree nodes.  Perhaps
we could also code the IL level in the trees to know what level we're
at?


Diego.