[llvm] [Docs][llvm-exegesis] Add documentation on validation counters option (PR #82132)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-binary-utilities

Author: Aiden Grossman (boomanaiden154)

<details>
<summary>Changes</summary>

This patch documents the --validation-counter flag.

---
Full diff: https://github.com/llvm/llvm-project/pull/82132.diff


1 Files Affected:

- (modified) llvm/docs/CommandGuide/llvm-exegesis.rst (+11) 


``````````diff
diff --git a/llvm/docs/CommandGuide/llvm-exegesis.rst b/llvm/docs/CommandGuide/llvm-exegesis.rst
index 601082a78f1e2e..9e3c19078f1cce 100644
--- a/llvm/docs/CommandGuide/llvm-exegesis.rst
+++ b/llvm/docs/CommandGuide/llvm-exegesis.rst
@@ -443,6 +443,17 @@ OPTIONS
   when performing latency measurements. By default, llvm-exegesis will repeat
   a latency measurement enough times to balance run-time and noise reduction.
 
+.. option:: --validation-counter=[instructions-retired,l1d-cache-load-misses,
+   l1d-cache-store-misses,l1i-cache-load-misses,data-tlb-load-misses,
+   data-tld-store-misses,instruction-tlb-load-misses]
+
+   This option enables the use of validation counters, which measure additional
+   microarchitectural events like cache misses to validate snippet execution
+   conditions. These events are measured using the perf subsystem in a group
+   with the performance counter used to measure the value of interest. This
+   flag can be specified multiple times to measure multiple events. The maximum
+   number of validation counters is platform dependent.
+
 EXIT STATUS
 -----------
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/82132