https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93385
--- Comment #25 from Martin Jambor <jamborm at gcc dot gnu.org> --- (In reply to rguent...@suse.de from comment #21) > Btw, I'd much prefer to not first copy the stmts and then remove them. > Instead the DCE "analysis" can be done on the original IL and stmts > be "marked" to be elided during copying. That saves generating > SSA names and gimple stmts rather than needing to remove them after the > fact. It is of course easy to change the patch to do the analysis on the original and just create a hash_set of statements/SSA_NAMES to not copy. I'll do that. As far as remapping the removed values to ERROR_MARK, I'm not sure. We'd need to remap some SSA_NAMES of the same DECL differently than other names (e.g. default-definition of the removed PARM_DECL would get remapped to ERROR_MARK but not other SSA_NAMES and similarly for other SSA_NAMES derived from those default-defs) ...and ATM I do not know to what extent that is a problem. But I can try.
