: "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (inc), "=&r"(tmp)
: "0" (sum), "1" (iph), "2" (ihl), "3" (4),
"m"(*(volatile struct { int _[100]; } *)iph)
: "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (inc), "=&r"(tmp)
: "0" (sum), "1" (iph), "2" (ihl), "3" (4),
"m"(*(volatile struct { int _[100]; } *)iph)