https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80569
--- Comment #14 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> --- >> /var/folders/zz/zyxvpxvq6csfxvn_n000087r00021y/T//cchNxmiW.s:7:no such >> instruction: `shrx %eax, 4(%esp),%eax' > http://www.felixcloutier.com/x86/SARX:SHLX:SHRX.html Could be a bug in the old Apple as. However, the testcase is fishy in explicitly passing -m16. For multilibbed x86 targets, that gets overridden for the non-default multilibs (either with -m32 or m64).