diff --git a/include/llvm/ProfileData/CoverageMapping.h b/include/llvm/ProfileData/CoverageMapping.h
index a7c124adf33..15445b59963 100644
--- a/include/llvm/ProfileData/CoverageMapping.h
+++ b/include/llvm/ProfileData/CoverageMapping.h
@@ -274,6 +274,7 @@ struct CoverageSegment {
     Count = NewCount;
     HasCount = true;
   }
+  void addCount(uint64_t NewCount) { setCount(Count + NewCount); }
 };
 
 /// \brief Coverage information to be processed or displayed.
diff --git a/lib/ProfileData/CoverageMapping.cpp b/lib/ProfileData/CoverageMapping.cpp
index 540e6433322..06a950c2e40 100644
--- a/lib/ProfileData/CoverageMapping.cpp
+++ b/lib/ProfileData/CoverageMapping.cpp
@@ -19,11 +19,14 @@
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ProfileData/CoverageMappingReader.h"
 #include "llvm/ProfileData/InstrProfReader.h"
+#include "llvm/Support/Debug.h"
 #include "llvm/Support/ErrorHandling.h"
 
 using namespace llvm;
 using namespace coverage;
 
+#define DEBUG_TYPE "coverage-mapping"
+
 CounterExpressionBuilder::CounterExpressionBuilder(unsigned NumCounterValues) {
   Terms.resize(NumCounterValues);
 }
@@ -228,6 +231,7 @@ class SegmentBuilder {
 
   /// Start a segment with no count specified.
   void startSegment(unsigned Line, unsigned Col) {
+    DEBUG(dbgs() << "Top level segment at " << Line << ":" << Col << "\n");
     Segments.emplace_back(Line, Col, /*IsRegionEntry=*/false);
   }
 
@@ -242,9 +246,13 @@ class SegmentBuilder {
       Segments.emplace_back(Line, Col, IsRegionEntry);
       S = Segments.back();
     }
+    DEBUG(dbgs() << "Segment at " << Line << ":" << Col);
     // Set this region's count.
-    if (Region.Kind != coverage::CounterMappingRegion::SkippedRegion)
+    if (Region.Kind != coverage::CounterMappingRegion::SkippedRegion) {
+      DEBUG(dbgs() << " with count " << Region.ExecutionCount);
       Segments.back().setCount(Region.ExecutionCount);
+    }
+    DEBUG(dbgs() << "\n");
   }
 
   /// Start a segment for the given region.
@@ -272,9 +280,15 @@ public:
       while (!ActiveRegions.empty() &&
              ActiveRegions.back()->endLoc() <= Region.startLoc())
         popRegion();
-      // Add this region to the stack.
-      ActiveRegions.push_back(&Region);
-      startSegment(Region);
+      if (Segments.size() && Segments.back().Line == Region.LineStart &&
+          Segments.back().Col == Region.ColumnStart) {
+        if (Region.Kind != coverage::CounterMappingRegion::SkippedRegion)
+          Segments.back().addCount(Region.ExecutionCount);
+      } else {
+        // Add this region to the stack.
+        ActiveRegions.push_back(&Region);
+        startSegment(Region);
+      }
     }
     // Pop any regions that are left in the stack.
     while (!ActiveRegions.empty())
diff --git a/test/tools/llvm-cov/Inputs/templateInstantiations.covmapping b/test/tools/llvm-cov/Inputs/templateInstantiations.covmapping
new file mode 100644
index 00000000000..d2437360451
Binary files /dev/null and b/test/tools/llvm-cov/Inputs/templateInstantiations.covmapping differ
diff --git a/test/tools/llvm-cov/Inputs/templateInstantiations.profdata b/test/tools/llvm-cov/Inputs/templateInstantiations.profdata
new file mode 100644
index 00000000000..6ccf526b5f3
Binary files /dev/null and b/test/tools/llvm-cov/Inputs/templateInstantiations.profdata differ
diff --git a/test/tools/llvm-cov/showTemplateInstantiations.cpp b/test/tools/llvm-cov/showTemplateInstantiations.cpp
new file mode 100644
index 00000000000..2b72d83c013
--- /dev/null
+++ b/test/tools/llvm-cov/showTemplateInstantiations.cpp
@@ -0,0 +1,43 @@
+// RUN: llvm-cov show %S/Inputs/templateInstantiations.covmapping -instr-profile %S/Inputs/templateInstantiations.profdata -no-colors -filename-equivalence %s | FileCheck -check-prefix=CHECK -check-prefix=ALL %s
+// RUN: llvm-cov show %S/Inputs/templateInstantiations.covmapping -instr-profile %S/Inputs/templateInstantiations.profdata -no-colors -filename-equivalence -name=_Z4funcIbEiT_ %s | FileCheck -check-prefix=CHECK -check-prefix=FILTER %s
+
+// before coverage   // WHOLE-FILE:   | [[@LINE]]|// before
+                     // FILTER-NOT:   | [[@LINE-1]]|// before
+template<typename T> // ALL:          | [[@LINE]]|template<typename T>
+int func(T x) {      // ALL-NEXT:    2| [[@LINE]]|int func(T x) {
+  if(x)              // ALL-NEXT:    2| [[@LINE]]|  if(x)
+    return 0;        // ALL-NEXT:    1| [[@LINE]]|    return 0;
+  else               // ALL-NEXT:    1| [[@LINE]]|  else
+    return 1;        // ALL-NEXT:    1| [[@LINE]]|    return 1;
+  int j = 1;         // ALL-NEXT:    0| [[@LINE]]|  int j = 1;
+}                    // ALL-NEXT:    1| [[@LINE]]|}
+
+                     // CHECK:       {{^ *(\| )?}}_Z4funcIbEiT_:
+                     // CHECK-NEXT:  1| [[@LINE-9]]|int func(T x) {
+                     // CHECK-NEXT:  1| [[@LINE-9]]|  if(x)
+                     // CHECK-NEXT:  1| [[@LINE-9]]|    return 0;
+                     // CHECK-NEXT:  1| [[@LINE-9]]|  else
+                     // CHECK-NEXT:  0| [[@LINE-9]]|    return 1;
+                     // CHECK-NEXT:  0| [[@LINE-9]]|  int j = 1;
+                     // CHECK-NEXT:  1| [[@LINE-9]]|}
+
+                     // ALL:         {{^ *}}| _Z4funcIiEiT_:
+                     // FILTER-NOT:  {{^ *(\| )?}} _Z4funcIiEiT_:
+                     // ALL-NEXT:    1| [[@LINE-19]]|int func(T x) {
+                     // ALL-NEXT:    1| [[@LINE-19]]|  if(x)
+                     // ALL-NEXT:    0| [[@LINE-19]]|    return 0;
+                     // ALL-NEXT:    1| [[@LINE-19]]|  else
+                     // ALL-NEXT:    1| [[@LINE-19]]|    return 1;
+                     // ALL-NEXT:    0| [[@LINE-19]]|  int j = 1;
+                     // ALL-NEXT:    1| [[@LINE-19]]|}
+
+int main() {         // ALL:         1| [[@LINE]]|int main() {
+  func<int>(0);      // ALL-NEXT:    1| [[@LINE]]|  func<int>(0);
+  func<bool>(true);  // ALL-NEXT:    1| [[@LINE]]|  func<bool>(true);
+  return 0;          // ALL-NEXT:    1| [[@LINE]]|  return 0;
+}                    // ALL-NEXT:    1| [[@LINE]]|}
+// after coverage    // ALL-NEXT:     | [[@LINE]]|// after
+                     // FILTER-NOT:   | [[@LINE-1]]|// after
+
+// llvm-cov doesn't work on big endian yet
+// XFAIL: powerpc64-, s390x, mips-, mips64-, sparc