Index: include/llvm/Target/TargetOptions.h
===================================================================
--- include/llvm/Target/TargetOptions.h
+++ include/llvm/Target/TargetOptions.h
@@ -108,7 +108,7 @@
           DisableIntegratedAS(false), CompressDebugSections(false),
           RelaxELFRelocations(false), FunctionSections(false),
           DataSections(false), UniqueSectionNames(true), TrapUnreachable(false),
-          EmulatedTLS(false), EnableIPRA(false),
+          EmulatedTLS(false), EnableIPRA(false), ProfileDebug(false),
           FloatABIType(FloatABI::Default),
           AllowFPOpFusion(FPOpFusion::Standard),
           ThreadModel(ThreadModel::POSIX),
@@ -225,6 +225,9 @@
     /// This flag enables InterProcedural Register Allocation (IPRA).
     unsigned EnableIPRA : 1;
 
+    /// This flag enables emitting extra debug info for sample profiling.
+    unsigned ProfileDebug : 1;
+
     /// FloatABIType - This setting is set by -float-abi=xxx option is specfied
     /// on the command line. This setting may either be Default, Soft, or Hard.
     /// Default selects the target's default behavior. Soft selects the ABI for
@@ -299,7 +302,8 @@
     ARE_EQUAL(FPDenormalMode) &&
     ARE_EQUAL(ExceptionModel) &&
     ARE_EQUAL(MCOptions) &&
-    ARE_EQUAL(EnableIPRA);
+    ARE_EQUAL(EnableIPRA) &&
+    ARE_EQUAL(ProfileDebug);
 #undef ARE_EQUAL
 }
 
Index: lib/CodeGen/AsmPrinter/DwarfDebug.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1137,8 +1137,10 @@
   TheCU.addRange(RangeSpan(Asm->getFunctionBegin(), Asm->getFunctionEnd()));
 
   // Under -gmlt, skip building the subprogram if there are no inlined
-  // subroutines inside it.
-  if (TheCU.getCUNode()->getEmissionKind() == DICompileUnit::LineTablesOnly &&
+  // subroutines inside it. But with -fprofile-debug, the subprogram is still
+  // needed as we need its source location.
+  if (!Asm->TM.Options.ProfileDebug &&
+      TheCU.getCUNode()->getEmissionKind() == DICompileUnit::LineTablesOnly &&
       LScopes.getAbstractScopesList().empty() && !IsDarwin) {
     assert(InfoHolder.getScopeVariables().empty());
     assert(DbgValues.empty());
Index: lib/CodeGen/AsmPrinter/DwarfUnit.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -1185,7 +1185,9 @@
 
 void DwarfUnit::applySubprogramAttributes(const DISubprogram *SP, DIE &SPDie,
                                           bool Minimal) {
-  if (!Minimal)
+  // If -fprofile-debug is enabled, need to emit the subprogram and its source
+  // location.
+  if (Asm->TM.Options.ProfileDebug || !Minimal)
     if (applySubprogramDefinitionAttributes(SP, SPDie))
       return;
 
@@ -1193,12 +1195,13 @@
   if (!SP->getName().empty())
     addString(SPDie, dwarf::DW_AT_name, SP->getName());
 
+  if (Asm->TM.Options.ProfileDebug || !Minimal)
+    addSourceLine(SPDie, SP);
+
   // Skip the rest of the attributes under -gmlt to save space.
   if (Minimal)
     return;
 
-  addSourceLine(SPDie, SP);
-
   // Add the prototype if we have a prototype and we have a C like
   // language.
   uint16_t Language = getLanguage();