Coverage: improve efficiency of the counter propagation to the expansion regions.

This patch reduces the complexity of the two inner loops in order to speed up
the loading of coverage data for very large functions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214228 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/ProfileData/CoverageMappingReader.cpp b/lib/ProfileData/CoverageMappingReader.cpp
index 21acae1bbdd3aaf993e8003e1e346b2dceb64a77..75ade55e2ed148e98b81e92fff9e0f2ffcaa8249 100644 (file)
--- a/lib/ProfileData/CoverageMappingReader.cpp
+++ b/lib/ProfileData/CoverageMappingReader.cpp
@@ -251,15 +251,19 @@ std::error_code RawCoverageMappingReader::read(CoverageMappingRecord &Record) {
   // from the expanded file.
   // Perform multiple passes to correctly propagate the counters through
   // all the nested expansion regions.
   // from the expanded file.
   // Perform multiple passes to correctly propagate the counters through
   // all the nested expansion regions.

+  SmallVector<CounterMappingRegion *, 8> FileIDExpansionRegionMapping;
+  FileIDExpansionRegionMapping.resize(VirtualFileMapping.size(), nullptr);

   for (unsigned Pass = 1, S = VirtualFileMapping.size(); Pass < S; ++Pass) {
   for (unsigned Pass = 1, S = VirtualFileMapping.size(); Pass < S; ++Pass) {

-    for (auto &I : MappingRegions) {
-      if (I.Kind == CounterMappingRegion::ExpansionRegion) {
-        for (const auto &J : MappingRegions) {
-          if (J.FileID == I.ExpandedFileID) {
-            I.Count = J.Count;
-            break;
-          }
-        }
+    for (auto &R : MappingRegions) {
+      if (R.Kind != CounterMappingRegion::ExpansionRegion)
+        continue;
+      assert(!FileIDExpansionRegionMapping[R.ExpandedFileID]);
+      FileIDExpansionRegionMapping[R.ExpandedFileID] = &R;
+    }
+    for (auto &R : MappingRegions) {
+      if (FileIDExpansionRegionMapping[R.FileID]) {
+        FileIDExpansionRegionMapping[R.FileID]->Count = R.Count;
+        FileIDExpansionRegionMapping[R.FileID] = nullptr;

       }
     }
   }
       }
     }
   }