https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83396
--- Comment #17 from Alexandre Oliva <aoliva at gcc dot gnu.org> --- Rainier, I wasn't sure how "same" the bootstrap failure you'd observed was, that's why I'd asked for a preprocessed testcase. Now, since the patch fixed the problem, nevermind. I'll look into the regression, though since it remains it's unlikely to be the same underlying issue. It's quite plausible that it's also caused by the SFN patchset, just like the failures Joseph mentioned. Joseph, I suppose those builds are automated; how often do they run? I shall watch it out for remaining problems once this fix goes in. Thanks! David, thanks for confirming that reversal allows bootstrap to complete. I'm a bit surprised, however, that you didn't run into any compare errors. Although -fcompare-debug is a bit more stringent, I'm seeing actual codegen diffs (with the proposed patch). Did you skip bootstrap compare, or are you not using the default bootstrap-debug configuration (that would probably have caught this codegen diff)?