[PATCH] D72032: [llvm-exegesis] Add pfm counters for Zen2 (znver2).

Clement Courbet via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Thu Jan 30 00:47:02 PST 2020


courbet marked an inline comment as done.
courbet added inline comments.


================
Comment at: llvm/lib/Target/X86/X86PfmCounters.td:231
+  let IssueCounters = [
+    // FIXME: In the current model, all three AGUs are considered the same,
+    // but only two are supposed to be able to compute load addresses.
----------------
GGanesh wrote:
> Can you please help me to comprehend this better.
> Zen2 has an AGU scheduler which services the AGU pipelines. 
> So why are we considering only two will be able to compute load addresses?
I'm not familiar at all with how AMD microarchitetcures work, but from https://en.wikichip.org/wiki/amd/microarchitectures/zen_2 I understand that not all AGUs can do the same things ?

> Two AGUs can generate addresses for load operations and send them to the load queue. All three AGUs can generate addresses for store operations and send them to the store queue. 




Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D72032/new/

https://reviews.llvm.org/D72032





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