[llvm] r354767 - [llvm-exegesis] Split Epsilon param into two (PR40787)

Roman Lebedev via llvm-commits llvm-commits at lists.llvm.org
Mon Feb 25 01:36:12 PST 2019


Author: lebedevri
Date: Mon Feb 25 01:36:12 2019
New Revision: 354767

URL: http://llvm.org/viewvc/llvm-project?rev=354767&view=rev
Log:
[llvm-exegesis] Split Epsilon param into two (PR40787)

Summary:
This eps param is used for two distinct things:
* initial point clusterization
* checking clusters against the llvm values

What if one wants to only look at highly different clusters, without changing
the clustering itself? In particular, this helps to weed out noisy measurements
(since the clusterization epsilon is still small, so there is a better chance
that noisy measurements from the same opcode will go into different clusters)

By splitting it into two params it is now possible.

This is nearly-free performance-wise:
Old:
```
$ perf stat -r 25 ./bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency-1.yaml -analysis-inconsistencies-output-file=/tmp/clusters-old.html
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 10099 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-old.html'
...
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency-1.yaml -analysis-inconsistencies-output-file=/tmp/clusters-old.html' (25 runs):

            390.01 msec task-clock                #    0.998 CPUs utilized            ( +-  0.25% )
                12      context-switches          #   31.735 M/sec                    ( +- 27.38% )
                 0      cpu-migrations            #    0.000 K/sec
              4745      page-faults               # 12183.732 M/sec                   ( +-  0.54% )
        1562711900      cycles                    # 4012303.327 GHz                   ( +-  0.24% )  (82.90%)
         185567822      stalled-cycles-frontend   #   11.87% frontend cycles idle     ( +-  0.52% )  (83.30%)
         392106234      stalled-cycles-backend    #   25.09% backend cycles idle      ( +-  1.31% )  (33.79%)
        1839236666      instructions              #    1.18  insn per cycle
                                                  #    0.21  stalled cycles per insn  ( +-  0.15% )  (50.37%)
         407035764      branches                  # 1045074878.710 M/sec              ( +-  0.12% )  (66.80%)
          10896459      branch-misses             #    2.68% of all branches          ( +-  0.17% )  (83.20%)

          0.390629 +- 0.000972 seconds time elapsed  ( +-  0.25% )
```
```
$ perf stat -r 9 ./bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency.yml -analysis-inconsistencies-output-file=/tmp/clusters-old.html
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 50572 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-old.html'
...
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency.yml -analysis-inconsistencies-output-file=/tmp/clusters-old.html' (9 runs):

           6803.36 msec task-clock                #    0.999 CPUs utilized            ( +-  0.96% )
               262      context-switches          #   38.546 M/sec                    ( +- 23.06% )
                 0      cpu-migrations            #    0.065 M/sec                    ( +- 76.03% )
             13287      page-faults               # 1953.206 M/sec                    ( +-  0.32% )
       27252537904      cycles                    # 4006024.257 GHz                   ( +-  0.95% )  (83.31%)
        1496314935      stalled-cycles-frontend   #    5.49% frontend cycles idle     ( +-  0.97% )  (83.32%)
       16128404524      stalled-cycles-backend    #   59.18% backend cycles idle      ( +-  0.30% )  (33.37%)
       17611143370      instructions              #    0.65  insn per cycle
                                                  #    0.92  stalled cycles per insn  ( +-  0.05% )  (50.04%)
        3894906599      branches                  # 572537147.437 M/sec               ( +-  0.03% )  (66.69%)
         116314514      branch-misses             #    2.99% of all branches          ( +-  0.20% )  (83.35%)

            6.8118 +- 0.0689 seconds time elapsed  ( +-  1.01%)
```
New:
```
$ perf stat -r 25 ./bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency-1.yaml -analysis-inconsistencies-output-file=/tmp/clusters-new.html
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 10099 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-new.html'
...
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency-1.yaml -analysis-inconsistencies-output-file=/tmp/clusters-new.html' (25 runs):

            400.14 msec task-clock                #    0.998 CPUs utilized            ( +-  0.66% )
                12      context-switches          #   29.429 M/sec                    ( +- 25.95% )
                 0      cpu-migrations            #    0.100 M/sec                    ( +-100.00% )
              4714      page-faults               # 11796.496 M/sec                   ( +-  0.55% )
        1603131306      cycles                    # 4011840.105 GHz                   ( +-  0.66% )  (82.85%)
         199538509      stalled-cycles-frontend   #   12.45% frontend cycles idle     ( +-  2.40% )  (83.10%)
         402249109      stalled-cycles-backend    #   25.09% backend cycles idle      ( +-  1.19% )  (34.05%)
        1847783963      instructions              #    1.15  insn per cycle
                                                  #    0.22  stalled cycles per insn  ( +-  0.18% )  (50.64%)
         407162722      branches                  # 1018925730.631 M/sec              ( +-  0.12% )  (67.02%)
          10932779      branch-misses             #    2.69% of all branches          ( +-  0.51% )  (83.28%)

           0.40077 +- 0.00267 seconds time elapsed  ( +-  0.67% )

lebedevri at pini-pini:/build/llvm-build-Clang-release$ perf stat -r 9 ./bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency.yml -analysis-inconsistencies-output-file=/tmp/clusters-new.html
no exegesis target for x86_64-unknown-linux-gnu, using default
Parsed 50572 benchmark points
Printing sched class consistency analysis results to file '/tmp/clusters-new.html'
...
 Performance counter stats for './bin/llvm-exegesis -mode=analysis -benchmarks-file=/home/lebedevri/PileDriver-Sched/benchmarks-latency.yml -analysis-inconsistencies-output-file=/tmp/clusters-new.html' (9 runs):

           6947.79 msec task-clock                #    1.000 CPUs utilized            ( +-  0.90% )
               217      context-switches          #   31.236 M/sec                    ( +- 36.16% )
                 1      cpu-migrations            #    0.096 M/sec                    ( +- 50.00% )
             13258      page-faults               # 1908.389 M/sec                    ( +-  0.34% )
       27830796523      cycles                    # 4006032.286 GHz                   ( +-  0.89% )  (83.30%)
        1504554006      stalled-cycles-frontend   #    5.41% frontend cycles idle     ( +-  2.10% )  (83.32%)
       16716574843      stalled-cycles-backend    #   60.07% backend cycles idle      ( +-  0.65% )  (33.38%)
       17755545931      instructions              #    0.64  insn per cycle
                                                  #    0.94  stalled cycles per insn  ( +-  0.09% )  (50.04%)
        3897255686      branches                  # 560980426.597 M/sec               ( +-  0.06% )  (66.70%)
         117045395      branch-misses             #    3.00% of all branches          ( +-  0.47% )  (83.34%)

            6.9507 +- 0.0627 seconds time elapsed  ( +-  0.90% )
```

I.e. it's +2.6% slowdown for one whole sweep, or +2% for 5 whole sweeps.
Within noise i'd say.

Should help with [[ https://bugs.llvm.org/show_bug.cgi?id=40787 | PR40787 ]].

Reviewers: courbet, gchatelet

Reviewed By: courbet

Subscribers: tschuett, RKSimon, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58476

Added:
    llvm/trunk/test/tools/llvm-exegesis/X86/analysis-epsilons.test
Modified:
    llvm/trunk/docs/CommandGuide/llvm-exegesis.rst
    llvm/trunk/test/tools/llvm-exegesis/X86/analysis-cluster-stabilization.test
    llvm/trunk/tools/llvm-exegesis/lib/Analysis.cpp
    llvm/trunk/tools/llvm-exegesis/lib/Analysis.h
    llvm/trunk/tools/llvm-exegesis/lib/Clustering.cpp
    llvm/trunk/tools/llvm-exegesis/lib/Clustering.h
    llvm/trunk/tools/llvm-exegesis/llvm-exegesis.cpp

Modified: llvm/trunk/docs/CommandGuide/llvm-exegesis.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/CommandGuide/llvm-exegesis.rst?rev=354767&r1=354766&r2=354767&view=diff
==============================================================================
--- llvm/trunk/docs/CommandGuide/llvm-exegesis.rst (original)
+++ llvm/trunk/docs/CommandGuide/llvm-exegesis.rst Mon Feb 25 01:36:12 2019
@@ -219,11 +219,16 @@ OPTIONS
  Specify the numPoints parameters to be used for DBSCAN clustering
  (`analysis` mode).
 
-.. option:: -analysis-epsilon=<dbscan epsilon parameter>
+.. option:: -analysis-clustering-epsilon=<dbscan epsilon parameter>
 
- Specify the numPoints parameters to be used for DBSCAN clustering
+ Specify the epsilon parameter used for clustering of benchmark points
  (`analysis` mode).
 
+.. option:: -analysis-inconsistency-epsilon=<epsilon>
+
+ Specify the epsilon parameter used for detection of when the cluster
+ is different from the LLVM schedule profile values (`analysis` mode).
+
 .. option:: -analysis-display-unstable-clusters
 
  If there is more than one benchmark for an opcode, said benchmarks may end up

Modified: llvm/trunk/test/tools/llvm-exegesis/X86/analysis-cluster-stabilization.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-exegesis/X86/analysis-cluster-stabilization.test?rev=354767&r1=354766&r2=354767&view=diff
==============================================================================
--- llvm/trunk/test/tools/llvm-exegesis/X86/analysis-cluster-stabilization.test (original)
+++ llvm/trunk/test/tools/llvm-exegesis/X86/analysis-cluster-stabilization.test Mon Feb 25 01:36:12 2019
@@ -1,6 +1,6 @@
-# RUN: llvm-exegesis -mode=analysis -benchmarks-file=%s -analysis-clusters-output-file=- -analysis-epsilon=0.1 -analysis-numpoints=1 | FileCheck -check-prefixes=CHECK-CLUSTERS %s
-# RUN: llvm-exegesis -mode=analysis -benchmarks-file=%s -analysis-inconsistencies-output-file=- -analysis-epsilon=0.5 -analysis-numpoints=1 | FileCheck -check-prefixes=CHECK-INCONSISTENCIES-ALL,CHECK-INCONSISTENCIES-STABLE %s
-# RUN: llvm-exegesis -mode=analysis -benchmarks-file=%s -analysis-inconsistencies-output-file=- -analysis-epsilon=0.5 -analysis-display-unstable-clusters -analysis-numpoints=1 | FileCheck -check-prefixes=CHECK-INCONSISTENCIES-ALL,CHECK-INCONSISTENCIES-UNSTABLE %s
+# RUN: llvm-exegesis -mode=analysis -benchmarks-file=%s -analysis-clusters-output-file=- -analysis-clustering-epsilon=0.1 -analysis-inconsistency-epsilon=0.1 -analysis-numpoints=1 | FileCheck -check-prefixes=CHECK-CLUSTERS %s
+# RUN: llvm-exegesis -mode=analysis -benchmarks-file=%s -analysis-inconsistencies-output-file=- -analysis-clustering-epsilon=0.5 -analysis-inconsistency-epsilon=0.5 -analysis-numpoints=1 | FileCheck -check-prefixes=CHECK-INCONSISTENCIES-ALL,CHECK-INCONSISTENCIES-STABLE %s
+# RUN: llvm-exegesis -mode=analysis -benchmarks-file=%s -analysis-inconsistencies-output-file=- -analysis-clustering-epsilon=0.5 -analysis-inconsistency-epsilon=0.5 -analysis-display-unstable-clusters -analysis-numpoints=1 | FileCheck -check-prefixes=CHECK-INCONSISTENCIES-ALL,CHECK-INCONSISTENCIES-UNSTABLE %s
 
 # We have one ADD32rr measurement, and two measurements for SQRTSSr.
 # The ADD32rr measurement and one of the SQRTSSr measurements are identical,

Added: llvm/trunk/test/tools/llvm-exegesis/X86/analysis-epsilons.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-exegesis/X86/analysis-epsilons.test?rev=354767&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-exegesis/X86/analysis-epsilons.test (added)
+++ llvm/trunk/test/tools/llvm-exegesis/X86/analysis-epsilons.test Mon Feb 25 01:36:12 2019
@@ -0,0 +1,63 @@
+# RUN: llvm-exegesis -mode=analysis -benchmarks-file=%s -analysis-clusters-output-file=- -analysis-clustering-epsilon=9 -analysis-inconsistency-epsilon=0.1 -analysis-numpoints=1 | FileCheck -check-prefixes=CHECK-CLUSTERS-ALL,CHECK-CLUSTERS-TWO %s
+# RUN: llvm-exegesis -mode=analysis -benchmarks-file=%s -analysis-clusters-output-file=- -analysis-clustering-epsilon=9 -analysis-inconsistency-epsilon=100 -analysis-numpoints=1 | FileCheck -check-prefixes=CHECK-CLUSTERS-ALL,CHECK-CLUSTERS-TWO %s
+# RUN: llvm-exegesis -mode=analysis -benchmarks-file=%s -analysis-clusters-output-file=- -analysis-clustering-epsilon=10 -analysis-inconsistency-epsilon=0.1 -analysis-numpoints=1 | FileCheck -check-prefixes=CHECK-CLUSTERS-ALL,CHECK-CLUSTERS-ONE %s
+# RUN: llvm-exegesis -mode=analysis -benchmarks-file=%s -analysis-clusters-output-file=- -analysis-clustering-epsilon=10 -analysis-inconsistency-epsilon=100 -analysis-numpoints=1 | FileCheck -check-prefixes=CHECK-CLUSTERS-ALL,CHECK-CLUSTERS-ONE %s
+
+# RUN: llvm-exegesis -mode=analysis -benchmarks-file=%s -analysis-inconsistencies-output-file=- -analysis-clustering-epsilon=9 -analysis-inconsistency-epsilon=0.1 -analysis-numpoints=1 | FileCheck -check-prefixes=CHECK-INCONSISTENCIES-FAIL %s
+# RUN: llvm-exegesis -mode=analysis -benchmarks-file=%s -analysis-inconsistencies-output-file=- -analysis-clustering-epsilon=10 -analysis-inconsistency-epsilon=0.1 -analysis-numpoints=1 | FileCheck -check-prefixes=CHECK-INCONSISTENCIES-FAIL %s
+# RUN: llvm-exegesis -mode=analysis -benchmarks-file=%s -analysis-inconsistencies-output-file=- -analysis-clustering-epsilon=9 -analysis-inconsistency-epsilon=100 -analysis-numpoints=1 | FileCheck -check-prefixes=CHECK-INCONSISTENCIES-PASS %s
+# RUN: llvm-exegesis -mode=analysis -benchmarks-file=%s -analysis-inconsistencies-output-file=- -analysis-clustering-epsilon=10 -analysis-inconsistency-epsilon=100 -analysis-numpoints=1 | FileCheck -check-prefixes=CHECK-INCONSISTENCIES-PASS %s
+
+# CHECK-CLUSTERS-ALL: {{^}}cluster_id,opcode_name,config,sched_class,latency{{$}}
+
+# CHECK-CLUSTERS-TWO: {{^}}0,
+# CHECK-CLUSTERS-TWO-SAME: ,90.00{{$}}
+# CHECK-CLUSTERS-TWO: {{^}}1,
+# CHECK-CLUSTERS-TWO-SAME: ,100.00{{$}}
+
+# CHECK-CLUSTERS-ONE: {{^}}0,
+# CHECK-CLUSTERS-ONE-SAME: ,90.00{{$}}
+# CHECK-CLUSTERS-ONE-NEXT: {{^}}0,
+# CHECK-CLUSTERS-ONE-SAME: ,100.00{{$}}
+
+# CHECK-INCONSISTENCIES-FAIL: contains instructions whose performance characteristics do not match that of LLVM
+# CHECK-INCONSISTENCIES-FAIL: contains instructions whose performance characteristics do not match that of LLVM
+# CHECK-INCONSISTENCIES-FAIL-NOT: contains instructions whose performance characteristics do not match that of LLVM
+
+# CHECK-INCONSISTENCIES-PASS-NOT: contains instructions whose performance characteristics do not match that of LLVM
+
+---
+mode:            latency
+key:
+  instructions:
+    - 'ADD32rr EDX EDX EAX'
+  config:          ''
+  register_initial_values:
+    - 'EDX=0x0'
+    - 'EAX=0x0'
+cpu_name:        bdver2
+llvm_triple:     x86_64-unknown-linux-gnu
+num_repetitions: 10000
+measurements:
+  - { key: latency, value: 90, per_snippet_value: 90 }
+error:           ''
+info:            Repeating a single implicitly serial instruction
+assembled_snippet: BA00000000B80000000001C201C201C201C201C201C201C201C201C201C201C201C201C201C201C201C2C3
+...
+---
+mode:            latency
+key:
+  instructions:
+    - 'SQRTSSr XMM11 XMM11'
+  config:          ''
+  register_initial_values:
+    - 'XMM11=0x0'
+cpu_name:        bdver2
+llvm_triple:     x86_64-unknown-linux-gnu
+num_repetitions: 10000
+measurements:
+  - { key: latency, value: 100, per_snippet_value: 100 }
+error:           ''
+info:            Repeating a single explicitly serial instruction
+assembled_snippet: 4883EC10C7042400000000C744240400000000C744240800000000C744240C00000000C57A6F1C244883C410F3450F51DBF3450F51DBF3450F51DBF3450F51DBF3450F51DBF3450F51DBF3450F51DBF3450F51DBF3450F51DBF3450F51DBF3450F51DBF3450F51DBF3450F51DBF3450F51DBF3450F51DBF3450F51DBC3
+...

Modified: llvm/trunk/tools/llvm-exegesis/lib/Analysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-exegesis/lib/Analysis.cpp?rev=354767&r1=354766&r2=354767&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-exegesis/lib/Analysis.cpp (original)
+++ llvm/trunk/tools/llvm-exegesis/lib/Analysis.cpp Mon Feb 25 01:36:12 2019
@@ -170,8 +170,11 @@ void Analysis::printInstructionRowCsv(co
 Analysis::Analysis(const llvm::Target &Target,
                    std::unique_ptr<llvm::MCInstrInfo> InstrInfo,
                    const InstructionBenchmarkClustering &Clustering,
+                   double AnalysisInconsistencyEpsilon,
                    bool AnalysisDisplayUnstableOpcodes)
     : Clustering_(Clustering), InstrInfo_(std::move(InstrInfo)),
+      AnalysisInconsistencyEpsilonSquared_(AnalysisInconsistencyEpsilon *
+                                           AnalysisInconsistencyEpsilon),
       AnalysisDisplayUnstableOpcodes_(AnalysisDisplayUnstableOpcodes) {
   if (Clustering.getPoints().empty())
     return;
@@ -301,7 +304,8 @@ void Analysis::printSchedClassClustersHt
   OS << "</tr>";
   for (const SchedClassCluster &Cluster : Clusters) {
     OS << "<tr class=\""
-       << (Cluster.measurementsMatch(*SubtargetInfo_, RSC, Clustering_)
+       << (Cluster.measurementsMatch(*SubtargetInfo_, RSC, Clustering_,
+                                     AnalysisInconsistencyEpsilonSquared_)
                ? "good-cluster"
                : "bad-cluster")
        << "\"><td>";
@@ -461,7 +465,8 @@ static unsigned findProcResIdx(const llv
 
 bool Analysis::SchedClassCluster::measurementsMatch(
     const llvm::MCSubtargetInfo &STI, const ResolvedSchedClass &RSC,
-    const InstructionBenchmarkClustering &Clustering) const {
+    const InstructionBenchmarkClustering &Clustering,
+    const double AnalysisInconsistencyEpsilonSquared_) const {
   const size_t NumMeasurements = Representative.size();
   std::vector<BenchmarkMeasure> ClusterCenterPoint(NumMeasurements);
   std::vector<BenchmarkMeasure> SchedClassPoint(NumMeasurements);
@@ -520,7 +525,8 @@ bool Analysis::SchedClassCluster::measur
     llvm_unreachable("unimplemented measurement matching mode");
     return false;
   }
-  return Clustering.isNeighbour(ClusterCenterPoint, SchedClassPoint);
+  return Clustering.isNeighbour(ClusterCenterPoint, SchedClassPoint,
+                                AnalysisInconsistencyEpsilonSquared_);
 }
 
 void Analysis::printSchedClassDescHtml(const ResolvedSchedClass &RSC,
@@ -689,7 +695,8 @@ llvm::Error Analysis::run<Analysis::Prin
     if (llvm::all_of(SchedClassClusters,
                      [this, &RSCAndPoints](const SchedClassCluster &C) {
                        return C.measurementsMatch(
-                           *SubtargetInfo_, RSCAndPoints.RSC, Clustering_);
+                           *SubtargetInfo_, RSCAndPoints.RSC, Clustering_,
+                           AnalysisInconsistencyEpsilonSquared_);
                      }))
       continue; // Nothing weird.
 

Modified: llvm/trunk/tools/llvm-exegesis/lib/Analysis.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-exegesis/lib/Analysis.h?rev=354767&r1=354766&r2=354767&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-exegesis/lib/Analysis.h (original)
+++ llvm/trunk/tools/llvm-exegesis/lib/Analysis.h Mon Feb 25 01:36:12 2019
@@ -38,6 +38,7 @@ public:
   Analysis(const llvm::Target &Target,
            std::unique_ptr<llvm::MCInstrInfo> InstrInfo,
            const InstructionBenchmarkClustering &Clustering,
+           double AnalysisInconsistencyEpsilon,
            bool AnalysisDisplayUnstableOpcodes);
 
   // Prints a csv of instructions for each cluster.
@@ -81,7 +82,8 @@ private:
     bool
     measurementsMatch(const llvm::MCSubtargetInfo &STI,
                       const ResolvedSchedClass &SC,
-                      const InstructionBenchmarkClustering &Clustering) const;
+                      const InstructionBenchmarkClustering &Clustering,
+                      const double AnalysisInconsistencyEpsilonSquared_) const;
 
     void addPoint(size_t PointId,
                   const InstructionBenchmarkClustering &Clustering);
@@ -127,6 +129,7 @@ private:
   std::unique_ptr<llvm::MCAsmInfo> AsmInfo_;
   std::unique_ptr<llvm::MCInstPrinter> InstPrinter_;
   std::unique_ptr<llvm::MCDisassembler> Disasm_;
+  const double AnalysisInconsistencyEpsilonSquared_;
   const bool AnalysisDisplayUnstableOpcodes_;
 };
 

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=354767&r1=354766&r2=354767&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-exegesis/lib/Clustering.cpp (original)
+++ llvm/trunk/tools/llvm-exegesis/lib/Clustering.cpp Mon Feb 25 01:36:12 2019
@@ -46,7 +46,8 @@ void InstructionBenchmarkClustering::ran
     const auto &PMeasurements = Points_[P].Measurements;
     if (PMeasurements.empty()) // Error point.
       continue;
-    if (isNeighbour(PMeasurements, QMeasurements)) {
+    if (isNeighbour(PMeasurements, QMeasurements,
+                    AnalysisClusteringEpsilonSquared_)) {
       Neighbors.push_back(P);
     }
   }
@@ -54,8 +55,9 @@ void InstructionBenchmarkClustering::ran
 
 InstructionBenchmarkClustering::InstructionBenchmarkClustering(
     const std::vector<InstructionBenchmark> &Points,
-    const double EpsilonSquared)
-    : Points_(Points), EpsilonSquared_(EpsilonSquared),
+    const double AnalysisClusteringEpsilonSquared)
+    : Points_(Points),
+      AnalysisClusteringEpsilonSquared_(AnalysisClusteringEpsilonSquared),
       NoiseCluster_(ClusterId::noise()), ErrorCluster_(ClusterId::error()) {}
 
 llvm::Error InstructionBenchmarkClustering::validateAndSetup() {
@@ -245,8 +247,10 @@ void InstructionBenchmarkClustering::sta
 llvm::Expected<InstructionBenchmarkClustering>
 InstructionBenchmarkClustering::create(
     const std::vector<InstructionBenchmark> &Points, const size_t MinPts,
-    const double Epsilon, llvm::Optional<unsigned> NumOpcodes) {
-  InstructionBenchmarkClustering Clustering(Points, Epsilon * Epsilon);
+    const double AnalysisClusteringEpsilon,
+    llvm::Optional<unsigned> NumOpcodes) {
+  InstructionBenchmarkClustering Clustering(
+      Points, AnalysisClusteringEpsilon * AnalysisClusteringEpsilon);
   if (auto Error = Clustering.validateAndSetup()) {
     return std::move(Error);
   }

Modified: llvm/trunk/tools/llvm-exegesis/lib/Clustering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-exegesis/lib/Clustering.h?rev=354767&r1=354766&r2=354767&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-exegesis/lib/Clustering.h (original)
+++ llvm/trunk/tools/llvm-exegesis/lib/Clustering.h Mon Feb 25 01:36:12 2019
@@ -29,7 +29,8 @@ public:
   // for more explanations on the algorithm.
   static llvm::Expected<InstructionBenchmarkClustering>
   create(const std::vector<InstructionBenchmark> &Points, size_t MinPts,
-         double Epsilon, llvm::Optional<unsigned> NumOpcodes = llvm::None);
+         double AnalysisClusteringEpsilon,
+         llvm::Optional<unsigned> NumOpcodes = llvm::None);
 
   class ClusterId {
   public:
@@ -103,7 +104,8 @@ public:
 
   // Returns true if the given point is within a distance Epsilon of each other.
   bool isNeighbour(const std::vector<BenchmarkMeasure> &P,
-                   const std::vector<BenchmarkMeasure> &Q) const {
+                   const std::vector<BenchmarkMeasure> &Q,
+                   const double EpsilonSquared_) const {
     double DistanceSquared = 0.0;
     for (size_t I = 0, E = P.size(); I < E; ++I) {
       const auto Diff = P[I].PerInstructionValue - Q[I].PerInstructionValue;
@@ -114,7 +116,8 @@ public:
 
 private:
   InstructionBenchmarkClustering(
-      const std::vector<InstructionBenchmark> &Points, double EpsilonSquared);
+      const std::vector<InstructionBenchmark> &Points,
+      double AnalysisClusteringEpsilonSquared);
 
   llvm::Error validateAndSetup();
   void dbScan(size_t MinPts);
@@ -122,7 +125,7 @@ private:
   void rangeQuery(size_t Q, std::vector<size_t> &Scratchpad) const;
 
   const std::vector<InstructionBenchmark> &Points_;
-  const double EpsilonSquared_;
+  const double AnalysisClusteringEpsilonSquared_;
   int NumDimensions_ = 0;
   // ClusterForPoint_[P] is the cluster id for Points[P].
   std::vector<ClusterId> ClusterIdForPoint_;

Modified: llvm/trunk/tools/llvm-exegesis/llvm-exegesis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-exegesis/llvm-exegesis.cpp?rev=354767&r1=354766&r2=354767&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-exegesis/llvm-exegesis.cpp (original)
+++ llvm/trunk/tools/llvm-exegesis/llvm-exegesis.cpp Mon Feb 25 01:36:12 2019
@@ -84,10 +84,15 @@ static cl::opt<unsigned> AnalysisNumPoin
     "analysis-numpoints",
     cl::desc("minimum number of points in an analysis cluster"), cl::init(3));
 
-static cl::opt<float>
-    AnalysisEpsilon("analysis-epsilon",
-                    cl::desc("dbscan epsilon for analysis clustering"),
-                    cl::init(0.1));
+static cl::opt<float> AnalysisClusteringEpsilon(
+    "analysis-clustering-epsilon",
+    cl::desc("dbscan epsilon for benchmark point clustering"), cl::init(0.1));
+
+static cl::opt<float> AnalysisInconsistencyEpsilon(
+    "analysis-inconsistency-epsilon",
+    cl::desc("epsilon for detection of when the cluster is different from the "
+             "LLVM schedule profile values"),
+    cl::init(0.1));
 
 static cl::opt<std::string>
     AnalysisClustersOutputFile("analysis-clusters-output-file", cl::desc(""),
@@ -444,9 +449,11 @@ static void analysisMain() {
   std::unique_ptr<llvm::MCInstrInfo> InstrInfo(TheTarget->createMCInstrInfo());
 
   const auto Clustering = ExitOnErr(InstructionBenchmarkClustering::create(
-      Points, AnalysisNumPoints, AnalysisEpsilon, InstrInfo->getNumOpcodes()));
+      Points, AnalysisNumPoints, AnalysisClusteringEpsilon,
+      InstrInfo->getNumOpcodes()));
 
   const Analysis Analyzer(*TheTarget, std::move(InstrInfo), Clustering,
+                          AnalysisInconsistencyEpsilon,
                           AnalysisDisplayUnstableOpcodes);
 
   maybeRunAnalysis<Analysis::PrintClusters>(Analyzer, "analysis clusters",




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