Index: lib/CodeGen/GlobalISel/Legalizer.cpp
===================================================================
--- lib/CodeGen/GlobalISel/Legalizer.cpp
+++ lib/CodeGen/GlobalISel/Legalizer.cpp
@@ -142,6 +142,7 @@
 
   // Populate Insts
   InstListTy InstList;
+  SmallVector<MachineInstr *, 16> RetryInstList;
   ArtifactListTy ArtifactList;
   ReversePostOrderTraversal<MachineFunction *> RPOT(&MF);
   // Perform legalization bottom up so we can DCE as we legalize.
@@ -195,6 +196,8 @@
   };
   bool Changed = false;
   do {
+    assert(RetryInstList.empty() &&
+           "Retry instructions should have been pushed into InstList");
     while (!InstList.empty()) {
       MachineInstr &MI = *InstList.pop_back_val();
       assert(isPreISelGenericOpcode(MI.getOpcode()) && "Expecting generic opcode");
@@ -209,10 +212,14 @@
       // Error out if we couldn't legalize this instruction. We may want to
       // fall back to DAG ISel instead in the future.
       if (Res == LegalizerHelper::UnableToLegalize) {
-        Helper.MIRBuilder.stopObservingChanges();
-        reportGISelFailure(MF, TPC, MORE, "gisel-legalize",
-                           "unable to legalize instruction", MI);
-        return false;
+        if (ArtifactList.empty()) {
+          Helper.MIRBuilder.stopObservingChanges();
+          reportGISelFailure(MF, TPC, MORE, "gisel-legalize",
+                             "unable to legalize instruction", MI);
+          return false;
+        }
+        LLVM_DEBUG(dbgs() << "Artifacts may prevent legalization to happen\n");
+        RetryInstList.push_back(&MI);
       }
       Changed |= Res == LegalizerHelper::Legalized;
     }
@@ -241,6 +248,9 @@
       else
         InstList.insert(&MI);
     }
+    for (MachineInstr *MI : RetryInstList)
+      InstList.insert(MI);
+    RetryInstList.clear();
   } while (!InstList.empty());
 
   // For now don't support if new blocks are inserted - we would need to fix the