[PATCH] D31503: [GlobalISel]: Fix bug where we can report GISelFailure on erased instructions

[Tim Northover via Phabricator via llvm-commits]

t.p.northover added a comment.

I'm not entirely keen on the pair solution. It seems to be designing the API around the (temporary) situation where legalization can routinely fail and need to fall back. In the long term most of these will be assertion failures.

Actually, I'm still unclear why the legalization doesn't know it'll fail before getting bogged down in erasing instructions. Normal instructions created while doing a single-step legalization would be added to the worklist to be seen by the top-level Legalizer wouldn't they?


Repository:
  rL LLVM

https://reviews.llvm.org/D31503