diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 4e261d9..ee36caa 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -2447,8 +2447,8 @@
     return;
   }
 
-  LocDeclsTy::iterator I = std::upper_bound(Decls->begin(), Decls->end(),
-                                            LocDecl, llvm::less_first());
+  LocDeclsTy::iterator I =
+      llvm::upper_bound(*Decls, LocDecl, llvm::less_first());
 
   Decls->insert(I, LocDecl);
 }
@@ -2473,9 +2473,9 @@
     return;
 
   LocDeclsTy::iterator BeginIt =
-      std::lower_bound(LocDecls.begin(), LocDecls.end(),
-                       std::make_pair(Offset, (Decl *)nullptr),
-                       llvm::less_first());
+      llvm::partition_point(LocDecls, [=](std::pair<unsigned, Decl *> LD) {
+        return LD.first < Offset;
+      });
   if (BeginIt != LocDecls.begin())
     --BeginIt;
 
@@ -2486,9 +2486,9 @@
          BeginIt->second->isTopLevelDeclInObjCContainer())
     --BeginIt;
 
-  LocDeclsTy::iterator EndIt = std::upper_bound(
-      LocDecls.begin(), LocDecls.end(),
-      std::make_pair(Offset + Length, (Decl *)nullptr), llvm::less_first());
+  LocDeclsTy::iterator EndIt = llvm::upper_bound(
+      LocDecls, std::make_pair(Offset + Length, (Decl *)nullptr),
+      llvm::less_first());
   if (EndIt != LocDecls.end())
     ++EndIt;