[llvm] [RegisterCoalescer] Try every commute partner that reads the copy destination (PR #230433)

[Aochang Liu via llvm-commits]

HelloWorldU wrote:

> > I looked into that before sending this. No end-to-end C example, sorry.
> 
> Haven't gone thru the full diff yet. Out of curiosity how did you find this bug considering its rarity? I'd argue the patch is definitely worth it if you did notice this in an actual compilation. Regardless I don't see this having any impact on compile time since (as you said) the loop only runs on contingency.

Thanks, at that time I was review my previous PR and found this FIXME nearby

https://github.com/llvm/llvm-project/pull/230433