[PATCH] D79868: [DebugInfo] Correct debuginfo for post-ra hoist and sink in Machine LICM

[Paul Robinson via Phabricator via llvm-commits]

probinson added a comment.

In D79868#2034196 <https://reviews.llvm.org/D79868#2034196>, @aprantl wrote:

> Can you explain why the sunk instruction's location is considered incorrect? I would have naively assumed that for profiling particularly, you would want to retain the original location to ensure that it is counted.


I should think profiling is mostly concerned about control flow, and a sampling profiler would infer control flow from the source location of the instruction.  If you sink an instruction but retain the original source location, a hit would be tallied for the moved-from block not the moved-to block, but the moved-to block would be more appropriate.  I might be misunderstanding the profiler's needs though, this is not an area I am super familiar with.


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https://reviews.llvm.org/D79868