https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65898
--- Comment #1 from stanley <sstsoft at wp dot pl> --- You could see another bug there "mov eax,%eax" -> %eax is generated from named value [val] "g" (val). I see there is my bug, to do such code without clobber "eax" so GCC put's optimized local value into my asm inline() and almost nop -> mov eax,eax produced.. i can fix that, but can someone fix bugs in GCC?