[PATCH] D100017: [GreedyRA ORE] Add stats for copy of virtual registers.

[Francis Visoiu Mistrih via Phabricator via llvm-commits]

thegameg added a comment.

In D100017#2673209 <https://reviews.llvm.org/D100017#2673209>, @skatkov wrote:

> In D100017#2673208 <https://reviews.llvm.org/D100017#2673208>, @thegameg wrote:
>
>> Is this really useful as a user-surfacing remark? Won't it have a really high false positive rate due to coalescing?
>
> To be honest - not sure. But if RA can assigned physical register and can eliminate copy it a good sign.
> So probably I also need to check reg map whether physical registers are different or not... Need to check...

IIRC, it actually inserts copies and relies on coalescing to remove most of them. It would be worth checking on large programs and such to see if you're actually seeing register copies for some of the remarks emitted.


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https://reviews.llvm.org/D100017