[PATCH] D45637: [DebugInfo] Ignore DBG_VALUE instructions in PostRA Machine Sink

[Matt Davis via Phabricator via llvm-commits]

mattd added a comment.

In https://reviews.llvm.org/D45637#1067916, @bjope wrote:

> In https://reviews.llvm.org/D45637#1067785, @vsk wrote:
>
> > Can this introduce a use-before-def scenario, where the DBG_VALUE for $eax occurs before the copy?
>
>
> I think it is the same kind of problem with sinking as I'm trying to solve (for instcombine) here: https://reviews.llvm.org/D45425
>  I suppose a similar solution would be OK, even if we are beyond SSA form here. So we should sink any DBG_VALUE with a debug-use of the register being defined by the sunken COPY.


I think you both are correct, thanks for the feedback!


https://reviews.llvm.org/D45637