> I'm asking to merge them (move them to fold_comparison). OK, I'll repost a first patch doing only the fold-const.c massaging.
> Yeah, it would be nice to see some support. The most interesting cases > will be symbolic-singleton +- CST where the offset shrinks a constant offset > in a symbolic A +- CST (thus we don't get into any overflow issues). Thus > handling > > [a + 1, a + 1] - [1, 1] -> [a, a] > > for example. We get the offsetted singleton symbolic ranges from > conditional asserts a lot. For the case at hand, you have [x + 1, INF] for y and you want to evaluate the range of y - x, so you really don't want to use the range of x... -- Eric Botcazou