Index: llvm/lib/Transforms/IPO/SampleProfile.cpp
===================================================================
--- llvm/lib/Transforms/IPO/SampleProfile.cpp
+++ llvm/lib/Transforms/IPO/SampleProfile.cpp
@@ -148,14 +148,17 @@
              "be accurate. It may be overriden by profile-sample-accurate. "));
 
 static cl::opt<bool> ProfileMergeInlinee(
-    "sample-profile-merge-inlinee", cl::Hidden, cl::init(false),
+    "sample-profile-merge-inlinee", cl::Hidden, cl::init(true),
     cl::desc("Merge past inlinee's profile to outline version if sample "
-             "profile loader decided not to inline a call site."));
+             "profile loader decided not to inline a call site. It will "
+             "only be enabled when top-down order of profile loading is "
+             "enabled. "));
 
 static cl::opt<bool> ProfileTopDownLoad(
-    "sample-profile-top-down-load", cl::Hidden, cl::init(false),
+    "sample-profile-top-down-load", cl::Hidden, cl::init(true),
     cl::desc("Do profile annotation and inlining for functions in top-down "
-             "order of call graph during sample profile loading."));
+             "order of call graph during sample profile loading. It only "
+             "works for new pass manager. "));
 
 static cl::opt<bool> ProfileSizeInline(
     "sample-profile-inline-size", cl::Hidden, cl::init(false),
@@ -1785,6 +1788,15 @@
   FunctionOrderList.reserve(M.size());
 
   if (!ProfileTopDownLoad || CG == nullptr) {
+    if (ProfileMergeInlinee) {
+      // Disable ProfileMergeInlinee if profile is not loaded in top down order,
+      // because the profile for a function may be used for the profile
+      // annotation of its outline copy before the profile merging of its
+      // non-inlined inline instances, and that is not the way how
+      // ProfileMergeInlinee is supposed to work.
+      ProfileMergeInlinee = false;
+    }
+
     for (Function &F : M)
       if (!F.isDeclaration() && F.hasFnAttribute("use-sample-profile"))
         FunctionOrderList.push_back(&F);
Index: llvm/test/Transforms/SampleProfile/inline-mergeprof.ll
===================================================================
--- llvm/test/Transforms/SampleProfile/inline-mergeprof.ll
+++ llvm/test/Transforms/SampleProfile/inline-mergeprof.ll
@@ -1,10 +1,10 @@
 ; Test we lose details of not inlined profile without '-sample-profile-merge-inlinee'
-; RUN: opt < %s -sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.prof -S | FileCheck -check-prefix=SCALE %s
-; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.prof -S | FileCheck -check-prefix=SCALE %s
+; RUN: opt < %s -sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.prof -sample-profile-merge-inlinee=false -S | FileCheck -check-prefix=SCALE %s
+; RUN: opt < %s -sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.prof -sample-profile-merge-inlinee=true -S | FileCheck -check-prefix=SCALE %s
+; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.prof -sample-profile-merge-inlinee=false -S | FileCheck -check-prefix=SCALE %s
 
 ; Test we properly merge not inlined profile properly with '-sample-profile-merge-inlinee'
-; RUN: opt < %s -sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.prof -sample-profile-merge-inlinee -S | FileCheck -check-prefix=MERGE %s
-; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.prof -sample-profile-merge-inlinee -S | FileCheck -check-prefix=MERGE  %s
+; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/inline-mergeprof.prof -sample-profile-merge-inlinee=true -S | FileCheck -check-prefix=MERGE  %s
 
 @.str = private unnamed_addr constant [11 x i8] c"sum is %d\0A\00", align 1
 
Index: llvm/test/Transforms/SampleProfile/inline-topdown.ll
===================================================================
--- llvm/test/Transforms/SampleProfile/inline-topdown.ll
+++ llvm/test/Transforms/SampleProfile/inline-topdown.ll
@@ -1,10 +1,10 @@
 ; Note that this needs new pass manager for now. Passing `-sample-profile-top-down-load` to legacy pass manager is a no-op.
 
 ; Test we aren't doing specialization for inlining with default source order
-; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/inline-topdown.prof -S | FileCheck -check-prefix=DEFAULT %s
+; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/inline-topdown.prof -sample-profile-top-down-load=false -S | FileCheck -check-prefix=DEFAULT %s
 
 ; Test we specialize based on call path with context-sensitive profile while inlining with '-sample-profile-top-down-load'
-; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/inline-topdown.prof -sample-profile-merge-inlinee -sample-profile-top-down-load -S | FileCheck -check-prefix=TOPDOWN  %s
+; RUN: opt < %s -passes=sample-profile -sample-profile-file=%S/Inputs/inline-topdown.prof -sample-profile-merge-inlinee -sample-profile-top-down-load=true -S | FileCheck -check-prefix=TOPDOWN  %s
 
 
 @.str = private unnamed_addr constant [11 x i8] c"sum is %d\0A\00", align 1