[PATCH] D12094: Avoid the propagation of debug locations in SelectionDAG via CSE

[Sergey Dmitrouk via llvm-commits]

sdmitrouk added a comment.

In http://reviews.llvm.org/D12094#238549, @wolfgangp wrote:

> We determine from the context whether the place where the node is reused is located earlier in the sequence of instructions.


So basically among all uses of the same CSEed node this picks debug location from the earliest one? And original issue could be rephrased as: debug location of CSEed nodes is picked non-deterministically. If that's the case, this seems to be really nice change.

> Sergey, I wasn't sure if we can subsume Constant nodes under this change, but it seemed that it's still better to null out the DebugLocation in those cases.


I agree, and it's safer to leave it as is, at least until counter example is provided.


http://reviews.llvm.org/D12094