diff --git a/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp b/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
index 52f9447..bda6176 100644
--- a/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
+++ b/llvm/lib/ProfileData/Coverage/CoverageMapping.cpp
@@ -671,6 +671,59 @@
   return ExpansionCoverage;
 }
 
+LineCoverageStats::LineCoverageStats(
+    ArrayRef<const coverage::CoverageSegment *> LineSegments,
+    const coverage::CoverageSegment *WrappedSegment, unsigned Line)
+    : ExecutionCount(0), HasMultipleRegions(false), Mapped(false), Line(Line),
+      LineSegments(LineSegments), WrappedSegment(WrappedSegment) {
+  // Find the minimum number of regions which start in this line.
+  unsigned MinRegionCount = 0;
+  auto isStartOfRegion = [](const coverage::CoverageSegment *S) {
+    return !S->IsGapRegion && S->HasCount && S->IsRegionEntry;
+  };
+  for (unsigned I = 0; I < LineSegments.size() && MinRegionCount < 2; ++I)
+    if (isStartOfRegion(LineSegments[I]))
+      ++MinRegionCount;
+
+  bool StartOfSkippedRegion = !LineSegments.empty() &&
+                              !LineSegments.front()->HasCount &&
+                              LineSegments.front()->IsRegionEntry;
+
+  HasMultipleRegions = MinRegionCount > 1;
+  Mapped =
+      !StartOfSkippedRegion &&
+      ((WrappedSegment && WrappedSegment->HasCount) || (MinRegionCount > 0));
+
+  if (!Mapped)
+    return;
+
+  // Pick the max count from the non-gap, region entry segments. If there
+  // aren't any, use the wrapped count.
+  if (!MinRegionCount) {
+    ExecutionCount = WrappedSegment->Count;
+    return;
+  }
+  for (const auto *LS : LineSegments)
+    if (isStartOfRegion(LS))
+      ExecutionCount = std::max(ExecutionCount, LS->Count);
+}
+
+LineCoverageIterator &LineCoverageIterator::operator++() {
+  if (Next == CD.end()) {
+    Stats = LineCoverageStats();
+    Ended = true;
+    return *this;
+  }
+  if (Segments.size())
+    WrappedSegment = Segments.back();
+  Segments.clear();
+  while (Next != CD.end() && Next->Line == Line)
+    Segments.push_back(&*Next++);
+  Stats = LineCoverageStats(Segments, WrappedSegment, Line);
+  ++Line;
+  return *this;
+}
+
 static std::string getCoverageMapErrString(coveragemap_error Err) {
   switch (Err) {
   case coveragemap_error::success: