Index: include/llvm/CodeGen/GlobalISel/CombinerHelper.h
===================================================================
--- include/llvm/CodeGen/GlobalISel/CombinerHelper.h
+++ include/llvm/CodeGen/GlobalISel/CombinerHelper.h
@@ -30,7 +30,6 @@
   MachineRegisterInfo &MRI;
   GISelChangeObserver &Observer;
 
-  void eraseInstr(MachineInstr &MI);
   void scheduleForVisit(MachineInstr &MI);
 
 public:
Index: include/llvm/CodeGen/GlobalISel/GISelChangeObserver.h
===================================================================
--- include/llvm/CodeGen/GlobalISel/GISelChangeObserver.h
+++ include/llvm/CodeGen/GlobalISel/GISelChangeObserver.h
@@ -18,7 +18,7 @@
 namespace llvm {
 /// Abstract class that contains various methods for clients to notify about
 /// changes. This should be the preferred way for APIs to notify changes.
-/// Typically calling erasedInstr/createdInstr multiple times should not affect
+/// Typically calling erasingInstr/createdInstr multiple times should not affect
 /// the result. The observer would likely need to check if it was already
 /// notified earlier (consider using GISelWorkList).
 class MachineInstr;
@@ -26,8 +26,8 @@
 public:
   virtual ~GISelChangeObserver() {}
 
-  /// An instruction was erased.
-  virtual void erasedInstr(MachineInstr &MI) = 0;
+  /// An instruction is about to be erased.
+  virtual void erasingInstr(MachineInstr &MI) = 0;
   /// An instruction was created and inserted into the function.
   virtual void createdInstr(MachineInstr &MI) = 0;
   /// This instruction was mutated in some way.
Index: lib/CodeGen/GlobalISel/Combiner.cpp
===================================================================
--- lib/CodeGen/GlobalISel/Combiner.cpp
+++ lib/CodeGen/GlobalISel/Combiner.cpp
@@ -43,7 +43,7 @@
   WorkListMaintainer(WorkListTy &WorkList) : WorkList(WorkList) {}
   virtual ~WorkListMaintainer() {}
 
-  void erasedInstr(MachineInstr &MI) override {
+  void erasingInstr(MachineInstr &MI) override {
     LLVM_DEBUG(dbgs() << "Erased: "; MI.print(dbgs()); dbgs() << "\n");
     WorkList.remove(&MI);
   }
Index: lib/CodeGen/GlobalISel/CombinerHelper.cpp
===================================================================
--- lib/CodeGen/GlobalISel/CombinerHelper.cpp
+++ lib/CodeGen/GlobalISel/CombinerHelper.cpp
@@ -23,9 +23,6 @@
                                MachineIRBuilder &B)
     : Builder(B), MRI(Builder.getMF().getRegInfo()), Observer(Observer) {}
 
-void CombinerHelper::eraseInstr(MachineInstr &MI) {
-  Observer.erasedInstr(MI);
-}
 void CombinerHelper::scheduleForVisit(MachineInstr &MI) {
   Observer.createdInstr(MI);
 }
@@ -299,8 +296,8 @@
     Observer.createdInstr(*NewMI);
   }
   for (auto &EraseMI : ScheduleForErase) {
+    Observer.erasingInstr(*EraseMI);
     EraseMI->eraseFromParent();
-    Observer.erasedInstr(*EraseMI);
   }
   MI.getOperand(0).setReg(ChosenDstReg);
 
Index: lib/CodeGen/GlobalISel/Legalizer.cpp
===================================================================
--- lib/CodeGen/GlobalISel/Legalizer.cpp
+++ lib/CodeGen/GlobalISel/Legalizer.cpp
@@ -94,7 +94,8 @@
     LLVM_DEBUG(dbgs() << ".. .. New MI: " << MI;);
   }
 
-  void erasedInstr(MachineInstr &MI) override {
+  void erasingInstr(MachineInstr &MI) override {
+    LLVM_DEBUG(dbgs() << ".. .. Erasing: " << MI;);
     InstList.remove(&MI);
     ArtifactList.remove(&MI);
   }
@@ -146,7 +147,7 @@
   const LegalizerInfo &LInfo(Helper.getLegalizerInfo());
   LegalizationArtifactCombiner ArtCombiner(Helper.MIRBuilder, MF.getRegInfo(), LInfo);
   auto RemoveDeadInstFromLists = [&WorkListObserver](MachineInstr *DeadMI) {
-    WorkListObserver.erasedInstr(*DeadMI);
+    WorkListObserver.erasingInstr(*DeadMI);
   };
   bool Changed = false;
   do {
@@ -175,7 +176,7 @@
       MachineInstr &MI = *ArtifactList.pop_back_val();
       assert(isPreISelGenericOpcode(MI.getOpcode()) && "Expecting generic opcode");
       if (isTriviallyDead(MI, MRI)) {
-        LLVM_DEBUG(dbgs() << MI << "Is dead; erasing.\n");
+        LLVM_DEBUG(dbgs() << MI << "Is dead\n");
         RemoveDeadInstFromLists(&MI);
         MI.eraseFromParentAndMarkDBGValuesForRemoval();
         continue;
@@ -183,7 +184,7 @@
       SmallVector<MachineInstr *, 4> DeadInstructions;
       if (ArtCombiner.tryCombineInstruction(MI, DeadInstructions)) {
         for (auto *DeadMI : DeadInstructions) {
-          LLVM_DEBUG(dbgs() << ".. Erasing Dead Instruction " << *DeadMI);
+          LLVM_DEBUG(dbgs() << *DeadMI << "Is dead\n");
           RemoveDeadInstFromLists(DeadMI);
           DeadMI->eraseFromParentAndMarkDBGValuesForRemoval();
         }
Index: unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
===================================================================
--- unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
+++ unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
@@ -15,7 +15,7 @@
 public:
   void changedInstr(MachineInstr &MI) override {}
   void createdInstr(MachineInstr &MI) override {}
-  void erasedInstr(MachineInstr &MI) override {}
+  void erasingInstr(MachineInstr &MI) override {}
 };
 
 // Test CTTZ expansion when CTTZ_ZERO_UNDEF is legal or custom,