On 11/01/2018 13:24, Thomas Huth wrote: >>>> + " st %2,4(%0)\n" >>>> + /* load the target address for our new PSW */ >>>> + " larl %1,cont\n" >>>> + " stg %1,8(%0)\n" >>>> + " lpswe 0(%0)\n" >>>> + "cont:\n" >>>> + : : "a" (&psw), "r" (0), "r" (1), "r" (enable) >>> The usage of "r" (0), "r" (1) looks wrong. I think you should rather put >>> them into the output list instead, since they are modified within the >>> assembler code. Or maybe even better, use fixed registers in the >>> assembler code and mark the corresponding registers in the clobber list. >> I tried to use the output list way and it would not let me specify >> immediates (0). So I have to introduce local variables. Or is there >> another way? > Use "+r"(0) in the output list? ... if that does not work, I think I'd > rather use the clobber list instead. You'd have to introduce local variables, yes. I think it's fine, perhaps also more self-documenting than "0" and "1" to s390-impaired me. Paolo
