[PATCH] D89048: [ARM][LowOverheadLoops] Insert loop start at end of block in more cases

[Sjoerd Meijer via Phabricator via llvm-commits]

SjoerdMeijer added a comment.

In D89048#2321000 <https://reviews.llvm.org/D89048#2321000>, @dmgreen wrote:

>> Insert loop start at end of block in more cases
>
> Hmm. Just a quick check - do we want that? I can see it improves some tail predication cases, that's good. But do we want that in general? The DLS instructions have a latency like any other, and earlier is better from that perspective. Or are we assuming that that latency will never matter into the LE instruction?

I wasn't so much concerned about latencies, but I was guessing that by moving the instruction, the goal is to get some more tail-predication "for free". That is suggesting to me that it is a work-around for the analysis of tail-predication not recognising that this is safe?


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https://reviews.llvm.org/D89048