https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87206
Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Severity|normal |enhancement Last reconfirmed| |2021-12-21 Status|UNCONFIRMED |NEW Ever confirmed|0 |1 --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Confirmed. Note GCC does produce better code than LLVM which produces two branches: mov ecx, 1 xor eax, eax lock cmpxchg dword ptr [rdi], ecx je .LBB0_2 # %bb.1: test eax, eax je .LBB0_2 # %bb.3: jmp bar # TAILCALL .LBB0_2: ret