[llvm] [Coverage] MCDC: Move findIndependencePairs deferred into MCDCRecord (PR #121188)

[NAKAMURA Takumi via llvm-commits]

================
@@ -451,19 +452,22 @@ struct MCDCRecord {
 private:
   CounterMappingRegion Region;
   TestVectors TV;
-  TVPairMap IndependencePairs;
+  std::optional<TVPairMap> IndependencePairs;
   BoolVector Folded;
   CondIDMap PosToID;
   LineColPairMap CondLoc;
 
 public:
   MCDCRecord(const CounterMappingRegion &Region, TestVectors &&TV,
-             TVPairMap &&IndependencePairs, BoolVector &&Folded,
-             CondIDMap &&PosToID, LineColPairMap &&CondLoc)
-      : Region(Region), TV(std::move(TV)),
-        IndependencePairs(std::move(IndependencePairs)),
-        Folded(std::move(Folded)), PosToID(std::move(PosToID)),
-        CondLoc(std::move(CondLoc)){};
+             BoolVector &&Folded, CondIDMap &&PosToID, LineColPairMap &&CondLoc)
+      : Region(Region), TV(std::move(TV)), Folded(std::move(Folded)),
+        PosToID(std::move(PosToID)), CondLoc(std::move(CondLoc)) {
+    findIndependencePairs();
+  }
+
+  // Compare executed test vectors against each other to find an independence
+  // pairs for each condition.  This processing takes the most time.
+  void findIndependencePairs();
----------------
chapuni wrote:

It'd make sense since it always flush and reconstruct the map.

https://github.com/llvm/llvm-project/pull/121188