[tree-ssa] COND_EXPR lowering preview

[Diego Novillo]

On Tue, 2003-08-26 at 14:53, Zdenek Dvorak wrote:

> here is the patch; since it is just preview and I am lazy, it includes
> some parts that should be separated, most imporatantly tree-ssa-dom fixes.
> The patch bootstraps and passes regtesting.
> 
Please separate them.

> It disables control structures removal in dce; this also has to be
> handled separately.
> 
What does this have to do with COND_EXPR lowering?

> It removes linearization from cfg cleanup, since the half of it
> is redundant with the patch and the rest contains several
> serious bugs (the most important one being that it uses merge_blocks; this
> function contains more bugs than correct code :-(
> 
Test cases?  Better yet.  Fixes?  Generalizations like this one are
hardly useful.

> Some possibly useful cleanups were removed from
> remove_useless_stmts_and_vars; this function is not suitable for
> work over unstructured code.
> 
Again.  Please separate this.  It has little to do with COND_EXPR
lowering.

> COND_EXPR lowering is being done in gimplification; if you like/dislike
> it, cry -- I personally have no opinion whether it should be done there
> or somewhere later.
> 
I still think we should separate this from the gimplifier.  We should
probably have a single lowering pass that runs immediately before we
build the flow graph.


Diego.