[PATCH] D54442: [llvm-exegesis] Optimize ToProcess in dbScan

[Fangrui Song via Phabricator via llvm-commits]

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


================
Comment at: tools/llvm-exegesis/lib/Clustering.cpp:134-135
       // Retrieve a point from the set.
-      const size_t Q = *ToProcess.begin();
-      ToProcess.erase(Q);
+      size_t Q = ToProcess.back();
+      ToProcess.pop_back();
 
----------------
lebedev.ri wrote:
> I did try this, at different stages of the patchset.
> It always measured to be slower than deque + pop front.
I moved the vector definition outside to avoid construction/destruction.

`Added` is not really necessary but it is faster than doing two checks: if an element is either Undef or Noise.


Repository:
  rL LLVM

https://reviews.llvm.org/D54442