"Alexander Konovalenko" <alexkon@xxxxxxxxx> writes: > There is an "add with carry" instruction on some architectures which > enables efficient implementation of arbitrary precision (bignum) > integer addition. Is it possible to make gcc generate efficient > machine code from pure C or C++ code for bignum addition on those > architectures? > > It looks like the popular libraries like GMP and CLN use hand-coded > assembly for that. I wonder if gcc can help rewrite that kind of code > in a more portable way. In general, no, except for the limiting case of the "long long" type. gcc doesn't provide any machine independent access to the carry flag. Ian
