https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121235
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- In fact my fixed up code is how it is written in the documentation even. int t1 = …; register int *p1 asm ("r0") = …; register int *p2 asm ("r1") = t1; register int *result asm ("r0"); asm ("sysint" : "=r" (result) : "0" (p1), "r" (p2)); Notice the use of p1/p2 in the inline-asm rather than t1.