[LiveRangeEdit] Remove any MemoryOperand on MI when converting it to KILL.

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/test/CodeGen/SystemZ/machine-ver-kill-memop.mir

@@ -0,0 +1,52 @@
+# RUN: llc -o /dev/null %s -mtriple=s390x-linux-gnu -mcpu=z16 \
+# RUN:   -verify-machineinstrs -run-pass=register-coalescer
+
+# 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, ptr %Src2) {
+    ret void
+  }
+...
+---
+name:            fun
+alignment:       16
+tracksRegLiveness: true
+noPhis:          true
+isSSA:           false
+noVRegs:         false
+hasFakeUses:     false
+registers:
+  - { id: 0, class: grx32bit }
+  - { id: 1, class: grx32bit }
+  - { id: 2, class: grx32bit }
+  - { id: 3, class: addr64bit }
+  - { id: 4, class: gr64bit }
+  - { id: 5, class: grx32bit }
+  - { id: 6, class: grx32bit }
+  - { id: 7, class: grx32bit }
+  - { id: 8, class: addr64bit }
+liveins:
+  - { reg: '$r2d', virtual-reg: '%3' }
+frameInfo:
+  maxAlignment:    1
+machineFunctionInfo: {}
+body:             |
+  bb.0:
+    liveins: $r2d
+
+    %3:addr64bit = COPY killed $r2d
+
+  bb.1:
+    %5:grx32bit = LMux killed %3, 0, $noreg :: (load (s32) from %ir.Src)
+    CHIMux killed %5, 0, implicit-def $cc
+    %7:grx32bit = LHIMux 0
+    %1:grx32bit = COPY killed %7
+    %1:grx32bit = LOCMux %1, undef %8:addr64bit, 0, 14, 6, implicit killed $cc :: (load (s32) from %ir.Src2)
+    dead %0:grx32bit = COPY killed %1
+
+  bb.2:
+    J %bb.2
+
+...