https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64058
--- Comment #9 from Jeffrey A. Law <law at redhat dot com> --- So if I take my code to renumber SSA_NAMES so they they're consistent irrespective how SSA_NAMEs were recycled and apply that on top of r216304 and r216305 the net result is I get the same code from those two compilers. That argues that ultimately this is another case of SSA_NAME_VERSION differences causing coalescing to make different decisions in a semi-random way which leads to random performance changes. That means this BZ and 68654 are likely manifestations of the same underlying issue. I'm still having some problems with getting consistent results across a larger codebase comparing before/after the SSA_NAME freelist flushing change, so clearly something isn't getting renumbered properly. But it's promising.
