[PATCH] D117003: [SchedModels][CortexA55] Add ASIMD integer instructioins

[Dave Green via Phabricator via llvm-commits]

dmgreen added a comment.

Hello.

I'm getting a few reports of this making performance worse, especially on Cortex-A510 cpu's. I think that adding the forwarding paths present on A55, but not available in A510 are causing more hazards and the performance to drop significantly in places, because they are compiled for cpu=generic. The A510 generally has higher throughput, but also higher latencies in places.

We may need to back out some of these changes, even if it makes the A55 model less precise. At least in the short term. We might need to take the route of not hurting other cpus, providing it doesn't help the A55 performance much.


Repository:
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https://reviews.llvm.org/D117003