[NFC][llvm-exegesis] Refactor Analysis::SchedClassCluster::measurementsMatch()

Summary:
The diff looks scary but it really isn't:
1. I moved the check for the number of measurements into `SchedClassClusterCentroid::validate()`
2. While there, added a check that we can only have a single inverse throughput measurement. I missed that when adding it initially.
3. In `Analysis::SchedClassCluster::measurementsMatch()` is called with the current LLVM values from schedule class and the values from Centroid.
3.1. The values from centroid we can already get from `SchedClassClusterCentroid::getAsPoint()`.
     This isn't 100% a NFC, because previously for inverse throughput we used `min()`. I have asked whether i have done that correctly in
     https://reviews.llvm.org/D57647?id=184939#inline-510384 but did not hear back. I think `avg()` should be used too, thus it is a fix.
3.2. Finally, refactor the computation of the LLVM-specified values into `Analysis::SchedClassCluster::getSchedClassPoint()`
     I will need that function for [[ https://bugs.llvm.org/show_bug.cgi?id=41275 | PR41275 ]]

Reviewers: courbet, gchatelet

Reviewed By: courbet

Subscribers: tschuett, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59951

llvm-svn: 357245

1 files changed, 31 insertions, 0 deletions

diff --git a/llvm/tools/llvm-exegesis/lib/Clustering.cpp b/llvm/tools/llvm-exegesis/lib/Clustering.cpp
index 2a8cc453be0..398bbf776af 100644
--- a/llvm/tools/llvm-exegesis/lib/Clustering.cpp
+++ b/llvm/tools/llvm-exegesis/lib/Clustering.cpp
@@ -363,5 +363,36 @@ std::vector<BenchmarkMeasure> SchedClassClusterCentroid::getAsPoint() const {
   return ClusterCenterPoint;
 }
 
+bool SchedClassClusterCentroid::validate(
+    InstructionBenchmark::ModeE Mode) const {
+  size_t NumMeasurements = Representative.size();
+  switch (Mode) {
+  case InstructionBenchmark::Latency:
+    if (NumMeasurements != 1) {
+      llvm::errs()
+          << "invalid number of measurements in latency mode: expected 1, got "
+          << NumMeasurements << "\n";
+      return false;
+    }
+    break;
+  case InstructionBenchmark::Uops:
+    // Can have many measurements.
+    break;
+  case InstructionBenchmark::InverseThroughput:
+    if (NumMeasurements != 1) {
+      llvm::errs() << "invalid number of measurements in inverse throughput "
+                      "mode: expected 1, got "
+                   << NumMeasurements << "\n";
+      return false;
+    }
+    break;
+  default:
+    llvm_unreachable("unimplemented measurement matching mode");
+    return false;
+  }
+
+  return true; // All good.
+}
+
 } // namespace exegesis
 } // namespace llvm