subtract
subtract(from, fromcap, totalfrom, crewfrom, pcfrom);
subtract(to, tocap, totalto, crewto, pcto);
subtract(from, fromcap, totalfrom, crewfrom, pcfrom);
subtract(to, tocap, totalto, crewto, pcto);
subtract(to, tocap, mento, crewto, pcto);
subtract(from, to, - mento, crewfrom, 0);
void subtract(struct ship *, struct ship *, int, int [3], int);
ATOMIC_ASM(subtract, char, "subb %b1,%0", "iq", v)
ATOMIC_ASM(subtract, short, "subw %w1,%0", "iq", v)
ATOMIC_ASM(subtract, int, "subl %1,%0", "iq", v)
ATOMIC_ASM(subtract, long, "subq %1,%0", "r", v)