[PATCH] D134521: [AArch64] Enable FeatureFuseAdrpAdd for all cpus

Mon Sep 26 00:04:06 PDT 2022

dmgreen added a comment.

Thanks

In D134521#3810990 <https://reviews.llvm.org/D134521#3810990>, @fhahn wrote:

> Should the title say *to all Cortex & Neoverse CPUs* instead of *all CPUs*? It looks like TuneThunderX2T99 for example doesn't have the feature unless I am missing something,

Oh yeah, I meant for all the Arm cpus.

In D134521#3810993 <https://reviews.llvm.org/D134521#3810993>, @peter.smith wrote:

> LGTM. I think all CPUs can benefit from the linker relaxation of the fused sequence. Worth leaving some time for any other reviewer to object.

Thanks. To add some detail I did a fair amount of benchmarking, which all looked fine for the cpus I tried. Even on a Cortex-A55 (an in-order cpu where scheduling is most useful), on a linker without relaxation for the adrp-add pair the performance seems OK. So I believe this is benign at worst, showing an improvement where the relaxation can occur.

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https://reviews.llvm.org/D134521