> I think we may be talking at different levels. It's my impression > that Richard K. was referring to local transformations like "a - a" -> > "0" once we are in the middle end. I agree that doing that > transformation close to the FE is undesirable, but once we are in the > middle end that should be fine.
That's exactly what I mean. If the FE cares about no folding taking place, it shouldn't fold. But once we're past the point that it's doing syntax and semantic checking, there's no optimization benefit in deferring the folding until we get to SSA, for example.
