Index: lib/CodeGen/CodeGenPGO.cpp
===================================================================
--- lib/CodeGen/CodeGenPGO.cpp
+++ lib/CodeGen/CodeGenPGO.cpp
@@ -93,6 +93,7 @@
     BinaryOperatorLAnd,
     BinaryOperatorLOr,
     BinaryConditionalOperator,
+    SimpleFunctionHash, // Reserved for functions without aforesaid statements.
 
     // Keep this last.  It's for the static assert that follows.
     LastHashType
@@ -598,7 +599,10 @@
     // No need to byte swap here, since none of the math was endian-dependent.
     // This number will be byte-swapped as required on endianness transitions,
     // so we will see the same value on the other side.
-    return Working;
+    // If we didn't meet any known statements, return a special hash value,
+    // so that any used function will have a non-zero hash and won't be
+    // messed up with non-used functions when reading coverage data.
+    return Working ? Working : static_cast<uint64_t>(SimpleFunctionHash);
 
   // Check for remaining work in Working.
   if (Working)
Index: lib/CodeGen/CoverageMappingGen.cpp
===================================================================
--- lib/CodeGen/CoverageMappingGen.cpp
+++ lib/CodeGen/CoverageMappingGen.cpp
@@ -906,9 +906,9 @@
 }
 
 static void dump(llvm::raw_ostream &OS, StringRef FunctionName,
-                 ArrayRef<CounterExpression> Expressions,
+                 uint64_t FuncHash, ArrayRef<CounterExpression> Expressions,
                  ArrayRef<CounterMappingRegion> Regions) {
-  OS << FunctionName << ":\n";
+  OS << FunctionName << "(" << FuncHash << "):\n";
   CounterMappingContext Ctx(Expressions);
   for (const auto &R : Regions) {
     OS.indent(2);
@@ -974,7 +974,7 @@
                                     Expressions, Regions);
     if (Reader.read())
       return;
-    dump(llvm::outs(), NameValue, Expressions, Regions);
+    dump(llvm::outs(), NameValue, FuncHash, Expressions, Regions);
   }
 }
 
Index: test/CoverageMapping/block-storage-starts-region.m
===================================================================
--- test/CoverageMapping/block-storage-starts-region.m
+++ test/CoverageMapping/block-storage-starts-region.m
@@ -3,7 +3,7 @@
 @interface Foo
 @end
 
-// CHECK-LABEL: doSomething:
+// CHECK-LABEL: doSomething
 void doSomething() { // CHECK: File 0, [[@LINE]]:20 -> {{[0-9:]+}} = #0
   return;
   __block Foo *f; // CHECK: File 0, [[@LINE]]:3 -> {{[0-9:]+}} = 0
Index: test/CoverageMapping/decl.c
===================================================================
--- test/CoverageMapping/decl.c
+++ test/CoverageMapping/decl.c
@@ -4,12 +4,12 @@
 // FileCheck -input-file %t %s
 // RUN: FileCheck -check-prefix BAR -input-file %t %s
 
-// FOO: foo:
-// FOO-NOT: foo:
+// FOO: foo
+// FOO-NOT: foo
 inline int foo() { return 0; }
 extern inline int foo();
 
-// BAR: bar:
-// BAR-NOT: bar:
+// BAR: bar
+// BAR-NOT: bar
 int bar() { return 0; }
 extern int bar();
Index: test/CoverageMapping/implicit-def-in-macro.m
===================================================================
--- test/CoverageMapping/implicit-def-in-macro.m
+++ test/CoverageMapping/implicit-def-in-macro.m
@@ -5,7 +5,7 @@
 #define Bar Foo
 
 @implementation Blah
-// CHECK-LABEL: +[Blah load]:
+// CHECK-LABEL: +[Blah load]
 + load { // CHECK: File 0, [[@LINE]]:8 -> [[END:[0-9:]+]] = #0
   return 0;
   // CHECK: Expansion,File 0, [[@LINE+1]]:3 -> [[@LINE+1]]:6 = 0
Index: test/CoverageMapping/lambda.cpp
===================================================================
--- test/CoverageMapping/lambda.cpp
+++ test/CoverageMapping/lambda.cpp
@@ -1,6 +1,6 @@
 // RUN: %clang_cc1 -x c++ -std=c++11 -triple %itanium_abi_triple -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping -emit-llvm-only %s -main-file-name lambda.cpp | FileCheck %s
 
-// CHECK-LABEL: _Z3fooi:
+// CHECK-LABEL: _Z3fooi
 void foo(int i) { // CHECK: File 0, [[@LINE]]:17 -> {{[0-9]+}}:2 = #0
   auto f = [](int x) {
     return x + 1;
Index: test/CoverageMapping/loops.cpp
===================================================================
--- test/CoverageMapping/loops.cpp
+++ test/CoverageMapping/loops.cpp
@@ -16,7 +16,7 @@
   if (sum) {}
 }
 
-                                    // CHECK: main:
+                                    // CHECK: main
 int main() {                        // CHECK-NEXT: File 0, [[@LINE]]:12 -> [[@LINE+24]]:2 = #0
                                     // CHECK-NEXT: File 0, [[@LINE+1]]:18 -> [[@LINE+1]]:24 = (#0 + #1)
   for(int i = 0; i < 10; ++i)       // CHECK-NEXT: File 0, [[@LINE]]:26 -> [[@LINE]]:29 = #1
Index: test/CoverageMapping/macroception.c
===================================================================
--- test/CoverageMapping/macroception.c
+++ test/CoverageMapping/macroception.c
@@ -5,7 +5,7 @@
 #define M22 }
 #define M11 M22
 
-// CHECK-LABEL: main:
+// CHECK-LABEL: main
 // CHECK-NEXT: Expansion,File 0, [[@LINE+2]]:12 -> [[@LINE+2]]:14 = #0
 // CHECK-NEXT: File 0, [[@LINE+1]]:14 -> [[@LINE+3]]:2 = #0
 int main() M1
@@ -15,7 +15,7 @@
 // CHECK-NEXT: Expansion,File 1, 4:12 -> 4:14 = #0
 // CHECK-NEXT: File 2, 3:12 -> 3:13 = #0
 
-// CHECK-LABEL: func2:
+// CHECK-LABEL: func2
 // CHECK-NEXT: File 0, [[@LINE+2]]:14 -> [[@LINE+4]]:4 = #0
 // CHECK-NEXT: Expansion,File 0, [[@LINE+3]]:1 -> [[@LINE+3]]:4 = #0
 void func2() {
@@ -25,7 +25,7 @@
 // CHECK-NEXT: Expansion,File 1, 6:13 -> 6:16 = #0
 // CHECK-NEXT: File 2, 5:13 -> 5:14 = #0
 
-// CHECK-LABEL: func3:
+// CHECK-LABEL: func3
 // CHECK-NEXT: Expansion,File 0, [[@LINE+3]]:14 -> [[@LINE+3]]:16 = #0
 // CHECK-NEXT: File 0, [[@LINE+2]]:16 -> [[@LINE+4]]:4 = #0
 // CHECK-NEXT: Expansion,File 0, [[@LINE+3]]:1 -> [[@LINE+3]]:4 = #0
@@ -39,7 +39,7 @@
 // CHECK-NEXT: File 3, 3:12 -> 3:13 = #0
 // CHECK-NEXT: File 4, 5:13 -> 5:14 = #0
 
-// CHECK-LABEL: func4:
+// CHECK-LABEL: func4
 // CHECK-NEXT: Expansion,File 0, [[@LINE+3]]:14 -> [[@LINE+3]]:16 = #0
 // CHECK-NEXT: File 0, [[@LINE+2]]:16 -> [[@LINE+2]]:20 = #0
 // CHECK-NEXT: Expansion,File 0, [[@LINE+1]]:17 -> [[@LINE+1]]:20 = #0
Index: test/CoverageMapping/moremacros.c
===================================================================
--- test/CoverageMapping/moremacros.c
+++ test/CoverageMapping/moremacros.c
@@ -3,7 +3,7 @@
 #define LBRAC {
 #define RBRAC }
 
-// CHECK: main:
+// CHECK: main
 // CHECK-NEXT: File 0, [[@LINE+1]]:40 -> {{[0-9]+}}:2 = #0
 int main(int argc, const char *argv[]) {
   // CHECK-NEXT: File 0, [[@LINE+1]]:7 -> [[@LINE+1]]:12 = #0
Index: test/CoverageMapping/simple-function-hash.cpp
===================================================================
--- /dev/null
+++ test/CoverageMapping/simple-function-hash.cpp
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -main-file-name simple-function-hash.cpp %s -o %t.o -emit-llvm -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping | FileCheck %s
+
+// Hash value for unused_func() is 0 because it is an inline function which is not used in the translation unit.
+// CHECK-DAG: _Z11unused_funcv(0):
+inline int unused_func() { return 1; }
+
+// Hash value for used_func() is 17 even though it does not contain any statement which affects hash.
+// CHECK-DAG: _Z9used_funcv(17):
+inline int used_func() { return 1; }
+
+// Hash value for main() is 10 because it contains the "if" statement.
+// CHECK-DAG: main(10):
+int main() {
+  if (used_func())
+    return used_func();
+  return 0;
+}
Index: test/CoverageMapping/system_macro.c
===================================================================
--- test/CoverageMapping/system_macro.c
+++ test/CoverageMapping/system_macro.c
@@ -11,7 +11,7 @@
 #define IS_SYSHEADER
 #include __FILE__
 
-// CHECK-LABEL: doSomething:
+// CHECK-LABEL: doSomething
 void doSomething(int x) { // CHECK: File 0, [[@LINE]]:25 -> {{[0-9:]+}} = #0
   Func(x); // CHECK: Expansion,File 0, [[@LINE]]:3 -> [[@LINE]]:7
   return;
Index: test/CoverageMapping/trymacro.cpp
===================================================================
--- test/CoverageMapping/trymacro.cpp
+++ test/CoverageMapping/trymacro.cpp
@@ -1,19 +1,19 @@
 // RUN: %clang_cc1 -triple %itanium_abi_triple -std=c++11 -fexceptions -fcxx-exceptions -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping -emit-llvm-only -main-file-name trymacro.cpp %s | FileCheck %s
 
-// CHECK: Z3fn1v:
+// CHECK: Z3fn1v
 void fn1() try { return; } // CHECK: [[@LINE]]:12 -> [[@LINE+1]]:14 = #1
 catch(...) {}              // CHECK: [[@LINE]]:12 -> [[@LINE]]:14 = #2
 
 #define RETURN_BLOCK { return; }
 
-// CHECK: Z3fn2v:
+// CHECK: Z3fn2v
 void fn2() try RETURN_BLOCK // CHECK: [[@LINE]]:12 -> [[@LINE+1]]:14 = #1
 catch(...) {}               // CHECK: [[@LINE]]:12 -> [[@LINE]]:14 = #2
 
 #define TRY try
 #define CATCH(x) catch (x)
 
-// CHECK: Z3fn3v:
+// CHECK: Z3fn3v
 void fn3() TRY { return; } // CHECK: [[@LINE]]:15 -> [[@LINE+1]]:14 = #1
 CATCH(...) {}              // CHECK: [[@LINE]]:12 -> [[@LINE]]:14 = #2
 
Index: test/Profile/Inputs/c-captured.proftext
===================================================================
--- test/Profile/Inputs/c-captured.proftext
+++ test/Profile/Inputs/c-captured.proftext
@@ -12,7 +12,7 @@
 1
 
 main
-0
+17
 1
 1
 
Index: test/Profile/Inputs/c-general.proftext
===================================================================
--- test/Profile/Inputs/c-general.proftext
+++ test/Profile/Inputs/c-general.proftext
@@ -145,7 +145,7 @@
 8
 
 main
-0
+17
 1
 1
 
Index: test/Profile/Inputs/c-outdated-data.proftext
===================================================================
--- test/Profile/Inputs/c-outdated-data.proftext
+++ test/Profile/Inputs/c-outdated-data.proftext
@@ -6,7 +6,7 @@
 0
 
 main
-0
+17
 1
 1
 
Index: test/Profile/Inputs/c-unprofiled.proftext
===================================================================
--- test/Profile/Inputs/c-unprofiled.proftext
+++ test/Profile/Inputs/c-unprofiled.proftext
@@ -5,6 +5,6 @@
 0
 
 main
-0
+17
 1
 1
Index: test/Profile/Inputs/cxx-class.proftext
===================================================================
--- test/Profile/Inputs/cxx-class.proftext
+++ test/Profile/Inputs/cxx-class.proftext
@@ -5,7 +5,7 @@
 100
 
 main
-0
+17
 1
 1
 
Index: test/Profile/Inputs/cxx-lambda.proftext
===================================================================
--- test/Profile/Inputs/cxx-lambda.proftext
+++ test/Profile/Inputs/cxx-lambda.proftext
@@ -6,7 +6,7 @@
 9
 
 main
-0
+17
 1
 1
 
Index: test/Profile/Inputs/cxx-rangefor.proftext
===================================================================
--- test/Profile/Inputs/cxx-rangefor.proftext
+++ test/Profile/Inputs/cxx-rangefor.proftext
@@ -8,6 +8,6 @@
 1
 
 main
-0
+17
 1
 1
Index: test/Profile/Inputs/cxx-templates.proftext
===================================================================
--- test/Profile/Inputs/cxx-templates.proftext
+++ test/Profile/Inputs/cxx-templates.proftext
@@ -1,5 +1,5 @@
 main
-0
+17
 1
 1
 
Index: test/Profile/Inputs/func-entry.proftext
===================================================================
--- test/Profile/Inputs/func-entry.proftext
+++ test/Profile/Inputs/func-entry.proftext
@@ -1,5 +1,5 @@
 foo
-0
+17
 1
 1000
 
Index: test/Profile/Inputs/max-function-count.proftext
===================================================================
--- test/Profile/Inputs/max-function-count.proftext
+++ test/Profile/Inputs/max-function-count.proftext
@@ -9,7 +9,7 @@
 
 main
 # Func Hash:
-0
+17
 # Num Counters:
 1
 # Counter Values:
Index: test/Profile/Inputs/objc-general.proftext
===================================================================
--- test/Profile/Inputs/objc-general.proftext
+++ test/Profile/Inputs/objc-general.proftext
@@ -11,7 +11,7 @@
 2
 
 main
-0
+17
 1
 1
 
Index: test/Profile/Inputs/profile-summary.proftext
===================================================================
--- test/Profile/Inputs/profile-summary.proftext
+++ test/Profile/Inputs/profile-summary.proftext
@@ -9,7 +9,7 @@
 
 main
 # Func Hash:
-0
+17
 # Num Counters:
 1
 # Counter Values: