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

[Quentin Colombet via Phabricator via llvm-commits]

qcolombet added a comment.

>> Here's another idea I considered: have legalizeInstr return the instruction it failed on, in a std::pair<LegalizeResult, MachineInstr*>.
> 
> How would that work with a deleted instruction?

Talked with Ahmed offline. He was thinking in terms of the current instruction being legalized.
Also given this is going to be used only for our own debugging purposes, the "it may be difficult to understand where it comes from" argument I made is pointless.

Therefore, Aditya, please go with Ahmed's idea. I would just suggest to print (in a DEBUG statement) the instruction we process or have some optimization remarks just for us (i.e., not emitted if !NDEBUG).


Repository:
  rL LLVM

https://reviews.llvm.org/D31503