[llvm] [MLGO] Count LR Evictions Rather than Relying on Cascade (PR #124440)

[Mircea Trofin via llvm-commits]

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@@ -657,7 +659,7 @@ bool MLEvictAdvisor::loadInterferenceFeatures(
       // threshold, prevent the range from being evicted. We still let the
       // range through if it is urgent as we are required to produce an
       // eviction if the candidate is not spillable.
-      if (IntfCascade >= MaxCascade && !Urgent)
+      if (VirtRegEvictionCounts[Intf->reg().id()] > MaxEvictionCount && !Urgent)
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mtrofin wrote:

why is it guaranteed `VirtRegEvictionCounts` has a value for `Intf->reg().id()` - or you're saying "if one not available, it's 0 here, so OK"? if so, comment that. It makes it clear to the reader.

https://github.com/llvm/llvm-project/pull/124440