Index: llvm/trunk/include/llvm/IR/DebugInfo.h
===================================================================
--- llvm/trunk/include/llvm/IR/DebugInfo.h
+++ llvm/trunk/include/llvm/IR/DebugInfo.h
@@ -39,11 +39,6 @@
 /// \brief Find subprogram that is enclosing this scope.
 DISubprogram *getDISubprogram(const MDNode *Scope);
 
-/// \brief Find debug info for a given function.
-///
-/// \returns a valid subprogram, if found. Otherwise, return \c nullptr.
-DISubprogram *getDISubprogram(const Function *F);
-
 /// \brief Generate map by visiting all retained types.
 DITypeIdentifierMap generateDITypeIdentifierMap(const NamedMDNode *CU_Nodes);
 
Index: llvm/trunk/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
===================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ llvm/trunk/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -412,7 +412,7 @@
   assert(Fn);
 
   StringRef FuncName;
-  if (auto *SP = getDISubprogram(GV))
+  if (auto *SP = GV->getSubprogram())
     FuncName = SP->getDisplayName();
 
   // If our DISubprogram name is empty, use the mangled name.
@@ -752,7 +752,7 @@
   assert(FnDebugInfo.count(GV));
   assert(CurFn == &FnDebugInfo[GV]);
 
-  collectVariableInfo(getDISubprogram(GV));
+  collectVariableInfo(GV->getSubprogram());
 
   DebugHandlerBase::endFunction(MF);
 
Index: llvm/trunk/lib/IR/DebugInfo.cpp
===================================================================
--- llvm/trunk/lib/IR/DebugInfo.cpp
+++ llvm/trunk/lib/IR/DebugInfo.cpp
@@ -38,23 +38,6 @@
   return nullptr;
 }
 
-DISubprogram *llvm::getDISubprogram(const Function *F) {
-  // We look for the first instr that has a debug annotation leading back to F.
-  for (auto &BB : *F) {
-    auto Inst = std::find_if(BB.begin(), BB.end(), [](const Instruction &Inst) {
-      return Inst.getDebugLoc();
-    });
-    if (Inst == BB.end())
-      continue;
-    DebugLoc DLoc = Inst->getDebugLoc();
-    const MDNode *Scope = DLoc.getInlinedAtScope();
-    auto *Subprogram = getDISubprogram(Scope);
-    return Subprogram->describes(F) ? Subprogram : nullptr;
-  }
-
-  return nullptr;
-}
-
 DITypeIdentifierMap
 llvm::generateDITypeIdentifierMap(const NamedMDNode *CU_Nodes) {
   DITypeIdentifierMap Map;
Index: llvm/trunk/lib/Transforms/IPO/SampleProfile.cpp
===================================================================
--- llvm/trunk/lib/Transforms/IPO/SampleProfile.cpp
+++ llvm/trunk/lib/Transforms/IPO/SampleProfile.cpp
@@ -1076,7 +1076,7 @@
 /// \returns the line number where \p F is defined. If it returns 0,
 ///          it means that there is no debug information available for \p F.
 unsigned SampleProfileLoader::getFunctionLoc(Function &F) {
-  if (DISubprogram *S = getDISubprogram(&F))
+  if (DISubprogram *S = F.getSubprogram())
     return S->getLine();
 
   // If the start of \p F is missing, emit a diagnostic to inform the user
@@ -1182,7 +1182,7 @@
     unsigned Coverage = CoverageTracker.computeCoverage(Used, Total);
     if (Coverage < SampleProfileRecordCoverage) {
       F.getContext().diagnose(DiagnosticInfoSampleProfile(
-          getDISubprogram(&F)->getFilename(), getFunctionLoc(F),
+          F.getSubprogram()->getFilename(), getFunctionLoc(F),
           Twine(Used) + " of " + Twine(Total) + " available profile records (" +
               Twine(Coverage) + "%) were applied",
           DS_Warning));
@@ -1195,7 +1195,7 @@
     unsigned Coverage = CoverageTracker.computeCoverage(Used, Total);
     if (Coverage < SampleProfileSampleCoverage) {
       F.getContext().diagnose(DiagnosticInfoSampleProfile(
-          getDISubprogram(&F)->getFilename(), getFunctionLoc(F),
+          F.getSubprogram()->getFilename(), getFunctionLoc(F),
           Twine(Used) + " of " + Twine(Total) + " available profile samples (" +
               Twine(Coverage) + "%) were applied",
           DS_Warning));
Index: llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -1891,7 +1891,7 @@
 
   int StackMallocIdx = -1;
   DebugLoc EntryDebugLocation;
-  if (auto SP = getDISubprogram(&F))
+  if (auto SP = F.getSubprogram())
     EntryDebugLocation = DebugLoc::get(SP->getScopeLine(), 0, SP);
 
   Instruction *InsBefore = AllocaVec[0];
Index: llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
+++ llvm/trunk/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
@@ -493,7 +493,7 @@
   bool IsEntryBB = &BB == &F.getEntryBlock();
   DebugLoc EntryLoc;
   if (IsEntryBB) {
-    if (auto SP = getDISubprogram(&F))
+    if (auto SP = F.getSubprogram())
       EntryLoc = DebugLoc::get(SP->getScopeLine(), 0, SP);
     // Keep static allocas and llvm.localescape calls in the entry block.  Even
     // if we aren't splitting the block, it's nice for allocas to be before
Index: llvm/trunk/lib/Transforms/Utils/AddDiscriminators.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Utils/AddDiscriminators.cpp
+++ llvm/trunk/lib/Transforms/Utils/AddDiscriminators.cpp
@@ -99,11 +99,6 @@
   return new AddDiscriminators();
 }
 
-static bool hasDebugInfo(const Function &F) {
-  DISubprogram *S = getDISubprogram(&F);
-  return S != nullptr;
-}
-
 /// \brief Assign DWARF discriminators.
 ///
 /// To assign discriminators, we examine the boundaries of every
@@ -161,7 +156,7 @@
   // Simlarly, if the function has no debug info, do nothing.
   // Finally, if this module is built with dwarf versions earlier than 4,
   // do nothing (discriminator support is a DWARF 4 feature).
-  if (NoDiscriminators || !hasDebugInfo(F) ||
+  if (NoDiscriminators || !F.getSubprogram() ||
       F.getParent()->getDwarfVersion() < 4)
     return false;
 
Index: llvm/trunk/test/Transforms/AddDiscriminators/call.ll
===================================================================
--- llvm/trunk/test/Transforms/AddDiscriminators/call.ll
+++ llvm/trunk/test/Transforms/AddDiscriminators/call.ll
@@ -8,7 +8,7 @@
 ; #5 }
 
 ; Function Attrs: uwtable
-define void @_Z3foov() #0 {
+define void @_Z3foov() #0 !dbg !4 {
   call void @_Z3barv(), !dbg !10
 ; CHECK:  call void @_Z3barv(), !dbg ![[CALL0:[0-9]+]]
   call void @_Z3barv(), !dbg !11