> I think with the patch validate_(unshare)_change becomes easier to use. You > can still decide locally if you want unsharing or not. Without taking into > account in which contexts your function gets called. I consider this a big > advantage.
You're supposed to know what you're doing though and unsharing just because of a single call to canonicalize_change_group in fold_rtx seems really overkill. > Otherwise we would have to look at every validate_change invocation in > order to check if it might get called after validate_unshare_change. This > sounds tedious and error-prone to me. (and probably we would end up using > validate_unshare_change everywhere) Well, this essentially works fine as of this writing so it's a little hard to buy this everything-is-probably-broken argument. canonicalize_change_group is special since it's part of the recog.c API; it needs to support intertwined calls with validate_change and validate_unshare_change. Once this is done, it's reasonable to expect that the user of the API doesn't do crazy things. -- Eric Botcazou
