This is the mail archive of the
mailing list for the GCC project.
Re: Fix a tcb crash and a potential bug on mainline
This may be something Andrew may want to look into as part
of his immediate uses work??
It's something we've pondered and talked about a little. Basically
with the immediate use work we would know where all the uses are
and we could probably arrange to delete those uses.
How would you delete those uses? You don't know if those statements
are dead, so you really can't do that.
If they are using the result of a deleted PHI or some other deleted
statement, then those statements must also be dead. It's one of
the nice SSA properties.
Only if your pass performs *all* insertions and updates to statements
before performing *any* removals of statements.
I believe some passes don't do this right now.
Otherwise, in the intermediate step, we would think some statements are
dead when they are only dead because we haven't fixed them up yet :)