[PATCH] D42293: [TableGen][AsmMatcherEmitter] Fix tied-constraint checking for InstAliases

[Sander de Smalen via Phabricator via llvm-commits]

sdesmalen added a comment.

@olista01 Thanks, I see your point about wanting to avoid taking the user through multiple steps to get the operand right, I think the work you did on reporting 'multiple near misses' is  a step in that direction by giving all the information to the user at once. Having the tied-constraint diagnostic being mentioned in that list would be useful.

When giving only a single diagnostic however, the difference with matching different operand classes and matching the tied operand's case is that there will be no other possible match that is more likely to match than the current one, so in a way the tied-operand diagnostic takes precedence over all other diagnostics in that case.

At the moment the checking of tied constraints is still disabled when 'ReportMultipleNearMisses' is used, maybe it is worth integrating the constraint checking with that work in a separate patch?


https://reviews.llvm.org/D42293