[PATCH] D118674: [nfc][mlgo][regalloc] Cache live interval feature components

[Mircea Trofin via Phabricator via llvm-commits]

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


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Comment at: llvm/lib/CodeGen/MLRegallocEvictAdvisor.cpp:252-255
+  void calculateSpillWeightAndHint(LiveInterval &LI) override {
+    VirtRegAuxInfo::calculateSpillWeightAndHint(LI);
+    CachedFeatures.erase(LI.reg().id());
+  }
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MatzeB wrote:
> Isn't this only ever computed once per live interval? I don't see any code computing this a 2nd time making it necessary to invalidate a cache...
> 
> The only user of this function is `VirtRegAuxInfo::calculateSpillWeightsAndHints` computing the initial spill weights when initializing the regalloc; and `LiveRangeEdit::calculateRegClassAndHint` which calls this function only for the newly created live intervals.
> 
> Why would you need to invalidate a cache then? 
Oh, true - so much simpler.

(separately, I wonder if I can remove setWeight and just ctor the LI with it pre-calculated)


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https://reviews.llvm.org/D118674