SSA_NAMEs not always released

[Jeffrey A Law]

On Wed, 2005-08-24 at 18:19 -0400, Andrew Pinski wrote:
> I am writing a "quick and dirty" DCE pass which is faster the
> current DCE and does not do anything with stores/loads.
FWIW, I've always been a fan of a very very simple DCE pass
which can be scheduled often, possibly after every pass that
might expose significant amounts of dead code -- leaving the
heavier weight DCE pass to run just once or twice to pick
up the rest of the crud.



>   It passes over all the live SSA_NAMEs by looping over ssa_name.
Which is not currently safe.


>   But I am running into places where SSA_NAMEs not released when they
>  become dead.  
Which is why it's not really safe.  We have never required SSA_NAMEs
to be released, we have only encouraged it to reduce memory consumption.
Currently any code must not assume that unused SSA_NAMEs have been
released.

Jeff