martong added a comment. In D102696#2769465 <https://reviews.llvm.org/D102696#2769465>, @NoQ wrote:
> In D102696#2767894 <https://reviews.llvm.org/D102696#2767894>, @martong wrote: > >>> This happens for the same reason that your patch is needed in the first >>> place: we're eagerly substituting a constant. >> >> Absolutely, that's the point. On the other hand, it is very important to >> emphasize that we cannot solve this problem with a stronger solver, see my >> example with 3 variables and two equations above. > > Well, in that other example, we should be asking about `$x + $y + 0 == 0` at > some point. And then the solver should be able to deduce it from `$x + $y + > $z == 0` and `$z == 0`. If we're not asking this question, that's obviously > the first problem to get out of our way. Yeah, you are right and my analysis was not precise enough. I confirm that currently - at main - we do query `$x + $y + 0 == 0`. And the solver is incapable of solving it from the given constraints. So, yes, this patch is a "workaround" to ask the solver what does it know from the value of the verbatim expression. And this has it's limitation (see the test case for commutativity), still I think it could make the analyzer more precise. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D102696/new/ https://reviews.llvm.org/D102696 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
