Remove the MMO instead in LiveRangeEdit.

Author: JonPsson1

llvm/lib/CodeGen/LiveRangeEdit.cpp

@@ -385,6 +385,7 @@ void LiveRangeEdit::eliminateDeadDef(MachineInstr *MI, ToShrinkSet &ToShrink) {
         continue;
       MI->removeOperand(i-1);
     }
+    MI->dropMemRefs(*MI->getMF());
     LLVM_DEBUG(dbgs() << "Converted physregs to:\t" << *MI);
   } else {
     // If the dest of MI is an original reg and MI is reMaterializable,

llvm/lib/CodeGen/MachineVerifier.cpp

@@ -2271,7 +2271,7 @@ void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
 
   // Check the MachineMemOperands for basic consistency.
   for (MachineMemOperand *Op : MI->memoperands()) {
-    if (Op->isLoad() && (!MI->mayLoad() && !MI->isKill()))
+    if (Op->isLoad() && !MI->mayLoad())
       report("Missing mayLoad flag", MI);
     if (Op->isStore() && !MI->mayStore())
       report("Missing mayStore flag", MI);

llvm/test/CodeGen/SystemZ/machine-ver-kill-memop.ll

@@ -1,8 +1,8 @@
 ; RUN: llc < %s -mtriple=s390x-linux-gnu -mcpu=z16 -disable-machine-dce \
 ; RUN:   -verify-machineinstrs -O3
 ;
-; Test that this passes the verifier even though a KILL instruction with a
-; dangling memory operand emerges.
+; Test that the MemoryOperand of the produced KILL instruction is removed
+; and as a result the machine verifier succeeds.
 
 define void @fun(ptr %Src, ptr %Dst) {
   br label %2