[tree-ssa] Switch stmts and inserting on edge

[Diego Novillo]

On Fri, 2003-05-30 at 15:06, Chris Lattner wrote:
> > The problem is that SWITCH_EXPRs still have implicit semantics that are
> > getting in the way.  I think this ought to be fixed by finishing Jason's
> > patch to expose SWITCH_EXPRs as explicit multi-way branches, or even
> > decision trees.
> 
> FWIW, this is what LLVM does, and it works quite well.  All fall-throughs
> are made into explicit gotos (the labels being merged if appropriate), and
> switch statements become multiway branches.
> 
Cool.  Do you guys change to decision trees if the case space is too
scattered?  I think we do this in RTL, but I don't know how we decide as
there may be target constraints as well.


Diego.