> In particular, a very large number of C and C++ programs are written > with the assumptions:
>- signed and unsigned types are modulo, except in loop induction > variables where it's bad taste Well, as demonstrated by INT_MIN/-1, gcc has NEVER fulfilled such assumptions on i86 and, quite likely, neither has or will any other compiler. The runtime penalty would be too big and hurt performance numbers. What I believe you can find examples of is that the more restricted claim of "addition and perhaps subtraction of signed numbers is modulo" is being assumed. That's cheap since (for 2-complement) signed addition is the same operation as unsigned addition. Morten
