Index: llvm/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp
+++ llvm/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp
@@ -212,6 +212,9 @@
                      cl::desc("Verify this pass produces no dead code"),
                      cl::Hidden);
 
+static cl::opt<bool> LowerGEPOpt("lower-gep", cl::init(false),
+                                 cl::desc("Enable GEP lowering"), cl::Hidden);
+
 namespace {
 
 /// A helper class for separating a constant offset from a GEP index.
@@ -1150,6 +1153,9 @@
   if (DisableSeparateConstOffsetFromGEP)
     return false;
 
+  if (LowerGEPOpt)
+    LowerGEP = true;
+
   auto *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
   auto *SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
   auto *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
@@ -1165,6 +1171,9 @@
   if (DisableSeparateConstOffsetFromGEP)
     return false;
 
+  if (LowerGEPOpt)
+    LowerGEP = true;
+
   DL = &F.getParent()->getDataLayout();
   bool Changed = false;
   for (BasicBlock &B : F) {