diff --git a/llvm/include/llvm/Transforms/Utils/Cloning.h b/llvm/include/llvm/Transforms/Utils/Cloning.h
--- a/llvm/include/llvm/Transforms/Utils/Cloning.h
+++ b/llvm/include/llvm/Transforms/Utils/Cloning.h
@@ -265,6 +265,14 @@
                             bool InsertLifetime = true,
                             Function *ForwardVarArgsTo = nullptr);
 
+/// In addition to what InlineFunction does, this function merges the callee's
+/// attributes into the caller's upon successful inlining.  You should call this
+/// function rather than InlineFunctionImpl if you are inlining a normal user
+/// function.
+InlineResult inlineFunctionAndMergeAttributes(
+    CallBase &CB, InlineFunctionInfo &IFI, AAResults *CalleeAAR = nullptr,
+    bool InsertLifetime = true, Function *ForwardVarArgsTo = nullptr);
+
 /// Clones a loop \p OrigLoop.  Returns the loop and the blocks in \p
 /// Blocks.
 ///
diff --git a/llvm/lib/Transforms/IPO/AlwaysInliner.cpp b/llvm/lib/Transforms/IPO/AlwaysInliner.cpp
--- a/llvm/lib/Transforms/IPO/AlwaysInliner.cpp
+++ b/llvm/lib/Transforms/IPO/AlwaysInliner.cpp
@@ -70,7 +70,7 @@
             &FAM.getResult<BlockFrequencyAnalysis>(*Caller),
             &FAM.getResult<BlockFrequencyAnalysis>(F));
 
-        InlineResult Res = InlineFunction(
+        InlineResult Res = inlineFunctionAndMergeAttributes(
             *CB, IFI, &FAM.getResult<AAManager>(F), InsertLifetime);
         if (!Res.isSuccess()) {
           ORE.emit([&]() {
@@ -88,9 +88,6 @@
             InlineCost::getAlways("always inline attribute"),
             /*ForProfileContext=*/false, DEBUG_TYPE);
 
-        // Merge the attributes based on the inlining.
-        AttributeFuncs::mergeAttributesForInlining(*Caller, F);
-
         Changed = true;
       }
 
diff --git a/llvm/lib/Transforms/IPO/Inliner.cpp b/llvm/lib/Transforms/IPO/Inliner.cpp
--- a/llvm/lib/Transforms/IPO/Inliner.cpp
+++ b/llvm/lib/Transforms/IPO/Inliner.cpp
@@ -315,15 +315,14 @@
 
   // Try to inline the function.  Get the list of static allocas that were
   // inlined.
-  InlineResult IR = InlineFunction(CB, IFI, &AAR, InsertLifetime);
+  InlineResult IR =
+      inlineFunctionAndMergeAttributes(CB, IFI, &AAR, InsertLifetime);
   if (!IR.isSuccess())
     return IR;
 
   if (InlinerFunctionImportStats != InlinerFunctionImportStatsOpts::No)
     ImportedFunctionsStats.recordInline(*Caller, *Callee);
 
-  AttributeFuncs::mergeAttributesForInlining(*Caller, *Callee);
-
   if (!DisableInlinedAllocaMerging)
     mergeInlinedArrayAllocas(Caller, IFI, InlinedArrayAllocas, InlineHistory);
 
@@ -914,8 +913,8 @@
           &FAM.getResult<BlockFrequencyAnalysis>(*(CB->getCaller())),
           &FAM.getResult<BlockFrequencyAnalysis>(Callee));
 
-      InlineResult IR =
-          InlineFunction(*CB, IFI, &FAM.getResult<AAManager>(*CB->getCaller()));
+      InlineResult IR = inlineFunctionAndMergeAttributes(
+          *CB, IFI, &FAM.getResult<AAManager>(*CB->getCaller()));
       if (!IR.isSuccess()) {
         Advice->recordUnsuccessfulInlining(IR);
         continue;
@@ -970,9 +969,6 @@
         }
       }
 
-      // Merge the attributes based on the inlining.
-      AttributeFuncs::mergeAttributesForInlining(F, Callee);
-
       // For local functions or discardable functions without comdats, check
       // whether this makes the callee trivially dead. In that case, we can drop
       // the body of the function eagerly which may reduce the number of callers
diff --git a/llvm/lib/Transforms/IPO/ModuleInliner.cpp b/llvm/lib/Transforms/IPO/ModuleInliner.cpp
--- a/llvm/lib/Transforms/IPO/ModuleInliner.cpp
+++ b/llvm/lib/Transforms/IPO/ModuleInliner.cpp
@@ -217,8 +217,8 @@
         &FAM.getResult<BlockFrequencyAnalysis>(*(CB->getCaller())),
         &FAM.getResult<BlockFrequencyAnalysis>(Callee));
 
-    InlineResult IR =
-        InlineFunction(*CB, IFI, &FAM.getResult<AAManager>(*CB->getCaller()));
+    InlineResult IR = inlineFunctionAndMergeAttributes(
+        *CB, IFI, &FAM.getResult<AAManager>(*CB->getCaller()));
     if (!IR.isSuccess()) {
       Advice->recordUnsuccessfulInlining(IR);
       continue;
@@ -251,9 +251,6 @@
       }
     }
 
-    // Merge the attributes based on the inlining.
-    AttributeFuncs::mergeAttributesForInlining(F, Callee);
-
     // For local functions, check whether this makes the callee trivially
     // dead. In that case, we can drop the body of the function eagerly
     // which may reduce the number of callers of other functions to one,
diff --git a/llvm/lib/Transforms/IPO/SampleProfile.cpp b/llvm/lib/Transforms/IPO/SampleProfile.cpp
--- a/llvm/lib/Transforms/IPO/SampleProfile.cpp
+++ b/llvm/lib/Transforms/IPO/SampleProfile.cpp
@@ -1221,13 +1221,9 @@
 
   InlineFunctionInfo IFI(nullptr, GetAC);
   IFI.UpdateProfile = false;
-  if (!InlineFunction(CB, IFI).isSuccess())
+  if (!inlineFunctionAndMergeAttributes(CB, IFI).isSuccess())
     return false;
 
-  // Merge the attributes based on the inlining.
-  AttributeFuncs::mergeAttributesForInlining(*BB->getParent(),
-                                             *CalledFunction);
-
   // The call to InlineFunction erases I, so we can't pass it here.
   emitInlinedIntoBasedOnCost(*ORE, DLoc, BB, *CalledFunction, *BB->getParent(),
                              Cost, true, getAnnotatedRemarkPassName());
diff --git a/llvm/lib/Transforms/Utils/InlineFunction.cpp b/llvm/lib/Transforms/Utils/InlineFunction.cpp
--- a/llvm/lib/Transforms/Utils/InlineFunction.cpp
+++ b/llvm/lib/Transforms/Utils/InlineFunction.cpp
@@ -2674,3 +2674,17 @@
 
   return InlineResult::success();
 }
+
+llvm::InlineResult llvm::inlineFunctionAndMergeAttributes(
+    CallBase &CB, InlineFunctionInfo &IFI, AAResults *CalleeAAR,
+    bool InsertLifetime, Function *ForwardVarArgsTo) {
+  Function *Callee = CB.getCalledFunction();
+  Function *Caller = CB.getCaller();
+  InlineResult IR =
+      InlineFunction(CB, IFI, CalleeAAR, InsertLifetime, ForwardVarArgsTo);
+
+  if (IR.isSuccess())
+    AttributeFuncs::mergeAttributesForInlining(*Caller, *Callee);
+
+  return IR;
+}