On Sun, Apr 03 2022 at 18:57, Thomas Gleixner wrote: > On Tue, Mar 29 2022 at 17:47, Ammar Faizi wrote: >> The asm constraint does not reflect that the asm statement can modify >> the value of @loops. But the asm statement in delay_loop() does modify >> the @loops. >> >> Specifiying the wrong constraint may lead to undefined behavior, it may >> clobber random stuff (e.g. local variable, important temporary value in >> regs, etc.). This is especially dangerous when the compiler decides to >> inline the function and since it doesn't know that the value gets >> modified, it might decide to use it from a register directly without >> reloading it. Ignore me, I misread this part of the explanation. Thanks, tglx