https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63155
--- Comment #44 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to Richard Biener from comment #43) > This makes CCP the main > offender again but as said the rectification would probably mean pulling > back the SSA SCC discovery code from SCCVN and use that in the SSA > propagator somehow. I take that back. SCC processing is quite fundamentally incompatible with the way SSA propagation works. But what would be possible is to add a non-optimistic mode to the SSA propagator removing the need to iterate at all. That's some non-trivial work though, possibly better spent teaching value-numbering the bits of CCP that it doesn't do (bit-value tracking, UNDEF handling) and then kill off CCP altogether.
