[clang-tools-extra] 17846ed - [clangd] Use ASTSignals in Heuristics CC Ranking.

[Utkarsh Saxena via cfe-commits]

Author: Utkarsh Saxena
Date: 2021-01-19T19:48:42+01:00
New Revision: 17846ed5af4a83334ef7d07f0b4a9d525e6ec0db

URL: https://github.com/llvm/llvm-project/commit/17846ed5af4a83334ef7d07f0b4a9d525e6ec0db
DIFF: https://github.com/llvm/llvm-project/commit/17846ed5af4a83334ef7d07f0b4a9d525e6ec0db.diff

LOG: [clangd] Use ASTSignals in Heuristics CC Ranking.

Differential Revision: https://reviews.llvm.org/D94927

Added: 
    

Modified: 
    clang-tools-extra/clangd/Quality.cpp

Removed: 
    


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diff  --git a/clang-tools-extra/clangd/Quality.cpp b/clang-tools-extra/clangd/Quality.cpp
index 1c41b7c7661f..b49392bc7d04 100644
--- a/clang-tools-extra/clangd/Quality.cpp
+++ b/clang-tools-extra/clangd/Quality.cpp
@@ -474,6 +474,21 @@ float SymbolRelevanceSignals::evaluateHeuristics() const {
   if (NeedsFixIts)
     Score *= 0.5f;
 
+  // Use a sigmoid style boosting function similar to `References`, which flats
+  // out nicely for large values. This avoids a sharp gradient for heavily
+  // referenced symbols. Use smaller gradient for ScopeRefsInFile since ideally
+  // MainFileRefs <= ScopeRefsInFile.
+  if (MainFileRefs >= 2) {
+    // E.g.: (2, 1.12), (9, 2.0), (48, 3.0).
+    float S = std::pow(MainFileRefs, -0.11);
+    Score *= 11.0 * (1 - S) / (1 + S) + 0.7;
+  }
+  if (ScopeRefsInFile >= 2) {
+    // E.g.: (2, 1.04), (14, 2.0), (109, 3.0), (400, 3.6).
+    float S = std::pow(ScopeRefsInFile, -0.10);
+    Score *= 10.0 * (1 - S) / (1 + S) + 0.7;
+  }
+
   return Score;
 }