[llvm] r349139 - Revert rL349136: [llvm-exegesis] Optimize ToProcess in dbScan
Simon Pilgrim via llvm-commits
llvm-commits at lists.llvm.org
Fri Dec 14 01:25:08 PST 2018
Author: rksimon
Date: Fri Dec 14 01:25:08 2018
New Revision: 349139
URL: http://llvm.org/viewvc/llvm-project?rev=349139&view=rev
Log:
Revert rL349136: [llvm-exegesis] Optimize ToProcess in dbScan
Summary:
Use `vector<char> Added + vector<size_t> ToProcess` to replace `SetVector ToProcess`
We also check `Added[P]` to enqueueing a point more than once, which
also saves us a `ClusterIdForPoint_[Q].isUndef()` check.
Reviewers: courbet, RKSimon, gchatelet, john.brawn, lebedev.ri
Subscribers: tschuett, llvm-commits
Differential Revision: https://reviews.llvm.org/D54442
........
Patch wasn't approved and breaks buildbots
Modified:
llvm/trunk/tools/llvm-exegesis/lib/Clustering.cpp
Modified: llvm/trunk/tools/llvm-exegesis/lib/Clustering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-exegesis/lib/Clustering.cpp?rev=349139&r1=349138&r2=349139&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-exegesis/lib/Clustering.cpp (original)
+++ llvm/trunk/tools/llvm-exegesis/lib/Clustering.cpp Fri Dec 14 01:25:08 2018
@@ -8,6 +8,7 @@
//===----------------------------------------------------------------------===//
#include "Clustering.h"
+#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallVector.h"
#include <string>
@@ -91,14 +92,8 @@ llvm::Error InstructionBenchmarkClusteri
}
void InstructionBenchmarkClustering::dbScan(const size_t MinPts) {
- const size_t NumPoints = Points_.size();
-
- // Persistent buffers to avoid allocs.
- std::vector<size_t> Neighbors;
- std::vector<size_t> ToProcess(NumPoints);
- std::vector<char> Added(NumPoints);
-
- for (size_t P = 0; P < NumPoints; ++P) {
+ std::vector<size_t> Neighbors; // Persistent buffer to avoid allocs.
+ for (size_t P = 0, NumPoints = Points_.size(); P < NumPoints; ++P) {
if (!ClusterIdForPoint_[P].isUndef())
continue; // Previously processed in inner loop.
rangeQuery(P, Neighbors);
@@ -114,18 +109,14 @@ void InstructionBenchmarkClustering::dbS
Cluster &CurrentCluster = Clusters_.back();
ClusterIdForPoint_[P] = CurrentCluster.Id; /* Label initial point */
CurrentCluster.PointIndices.push_back(P);
- Added[P] = 1;
// Process P's neighbors.
- size_t Tail = 0;
- for (size_t Q : Neighbors)
- if (!Added[Q]) {
- ToProcess[Tail++] = P;
- Added[Q] = 1;
- }
- for (size_t Head = 0; Head < Tail; ++Head) {
+ llvm::SetVector<size_t, std::deque<size_t>> ToProcess;
+ ToProcess.insert(Neighbors.begin(), Neighbors.end());
+ while (!ToProcess.empty()) {
// Retrieve a point from the set.
- size_t Q = ToProcess[Head];
+ const size_t Q = *ToProcess.begin();
+ ToProcess.erase(ToProcess.begin());
if (ClusterIdForPoint_[Q].isNoise()) {
// Change noise point to border point.
@@ -133,18 +124,17 @@ void InstructionBenchmarkClustering::dbS
CurrentCluster.PointIndices.push_back(Q);
continue;
}
- assert(ClusterIdForPoint_[Q].isUndef());
+ if (!ClusterIdForPoint_[Q].isUndef()) {
+ continue; // Previously processed.
+ }
// Add Q to the current custer.
ClusterIdForPoint_[Q] = CurrentCluster.Id;
CurrentCluster.PointIndices.push_back(Q);
// And extend to the neighbors of Q if the region is dense enough.
rangeQuery(Q, Neighbors);
- if (Neighbors.size() + 1 >= MinPts)
- for (size_t P : Neighbors)
- if (!Added[P]) {
- ToProcess[Tail++] = P;
- Added[P] = 1;
- }
+ if (Neighbors.size() + 1 >= MinPts) {
+ ToProcess.insert(Neighbors.begin(), Neighbors.end());
+ }
}
}
// assert(Neighbors.capacity() == (Points_.size() - 1));
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