[PATCH] D63476: [ARM] DLS/LE low-overhead loop code generation

[Dave Green via Phabricator via llvm-commits]

dmgreen added a comment.

How confident are you that this is always valid? From what I understand it creates an assumption that the code will not grow past this point in the pipeline (technically that the LE will not move further from the loop start). What would stop, for example, constant island pass from putting a constant pool into the loop?

And as Sjoerd says, I found out that DLS doesn't really do anything and can be ignored (all the "smarts" are in the LE). WLS obviously does more, and a DLSTP is important for tail predication. But if the count is already in lr, we needn't emit the DLS.


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  rL LLVM

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  https://reviews.llvm.org/D63476/new/

https://reviews.llvm.org/D63476