https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85620
H.J. Lu <hjl.tools at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|RESOLVED |REOPENED Resolution|WONTFIX |--- --- Comment #7 from H.J. Lu <hjl.tools at gmail dot com> --- We want to generate ENDBR after swapcontext. swapcontext didn't return the first time. It was just kind of "suspended". Mark it return twice will unnecessarily disable compiler optimization.