[llvm-dev] Help for DeadStoreElimination cross-block dependence

[Tianyu Cheng via llvm-dev]

Hi all,

I am working on a project that requires LLVM DeadStoreElimination
However, when I look through the code in Transforms/Scalar/DeadStoreElimination.cpp, I see the following:

    // Ignore any store where we can't find a local dependence.
    // FIXME: cross-block DSE would be fun. :)
    if (!InstDep.isDef() && !InstDep.isClobber())
      continue;

I have two questions on this code:I have two questions on this code:

1. What is a clobber?
2. Does the local dependence mean that the dependence should reside in the same basic bloWhat does the comment (FIXME: cross-block DSE would be fun) mean in this case?

Thanks,
Tianyu Cheng

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