[PATCH] D77422: [llvm-exegesis] Add benchmark mode that uses LBR for more precise measurements.

[Vy Nguyen via Phabricator via llvm-commits]

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


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Comment at: llvm/tools/llvm-exegesis/lib/Target.h:69
 
+  virtual Expected<std::unique_ptr<pfm::Counter>>
+  createCounter(const char *CounterName, const LLVMState &State) const;
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courbet wrote:
> Can you submit this change independently and rebase ? Thanks !
Done https://reviews.llvm.org/D80610


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Comment at: llvm/tools/llvm-exegesis/lib/X86/X86Counter.cpp:184
+    } else if (PollResult == 0) {
+      llvm::errs() << "LBR polling timed out without result, NumTimeouts ="
+                   << NumTimeouts << ". ";
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courbet wrote:
> how often does that happen ? Do we want that much logging ?
It could happen 100% of the time if the code happens to have no branches.
With "proper" input, it happens less frequently. I don't really have a sense of how often ... it's probably be fine to change this to llvm::debug() or something? 




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  https://reviews.llvm.org/D77422/new/

https://reviews.llvm.org/D77422