Index: lib/Passes/PassBuilder.cpp
===================================================================
--- lib/Passes/PassBuilder.cpp
+++ lib/Passes/PassBuilder.cpp
@@ -150,6 +150,10 @@
 
 static cl::opt<unsigned> MaxDevirtIterations("pm-max-devirt-iterations",
                                              cl::ReallyHidden, cl::init(4));
+static cl::opt<bool>
+RunPartialInlining("npm-partial-inlining", cl::init(false),
+                   cl::Hidden, cl::ZeroOrMore,
+                   cl::desc("Run Partial inlinining pass"));
 
 static cl::opt<bool> EnableGVNHoist(
     "enable-npm-gvn-hoist", cl::init(false), cl::Hidden,
@@ -552,6 +556,11 @@
   // At this point, we expect to have canonical and simple IR which we begin
   // *optimizing* for efficient execution going forward.
 
+  // Run partial inlining pass to partially inline functions that have
+  // large bodies.
+  if (RunPartialInlining)
+    MPM.addPass(PartialInlinerPass());
+
   // Eliminate externally available functions now that inlining is over -- we
   // won't emit these anyways.
   MPM.addPass(EliminateAvailableExternallyPass());
Index: lib/Transforms/IPO/PassManagerBuilder.cpp
===================================================================
--- lib/Transforms/IPO/PassManagerBuilder.cpp
+++ lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -44,6 +44,11 @@
 using namespace llvm;
 
 static cl::opt<bool>
+RunPartialInlining("partial-inlining", cl::init(false),
+                   cl::Hidden, cl::ZeroOrMore,
+                   cl::desc("Run Partial inlinining pass"));
+
+static cl::opt<bool>
 RunLoopVectorization("vectorize-loops", cl::Hidden,
                      cl::desc("Run the Loop vectorization passes"));
 
@@ -516,6 +521,8 @@
   // pass manager that we are specifically trying to avoid. To prevent this
   // we must insert a no-op module pass to reset the pass manager.
   MPM.add(createBarrierNoopPass());
+  if (RunPartialInlining)
+    MPM.add(createPartialInliningPass());
 
   if (!DisableUnitAtATime && OptLevel > 1 && !PrepareForLTO &&
       !PrepareForThinLTO)