1 files changed, 8 insertions, 2 deletions
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyExplicitLocals.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyExplicitLocals.cpp
index 8639cb9..b61fb34 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyExplicitLocals.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyExplicitLocals.cpp
@@ -284,8 +284,11 @@ bool WebAssemblyExplicitLocals::runOnMachineFunction(MachineFunction &MF) {
           }
           if (UseEmpty[TargetRegisterInfo::virtReg2Index(OldReg)]) {
             unsigned Opc = getDropOpcode(RC);
-            BuildMI(MBB, InsertPt, MI.getDebugLoc(), TII->get(Opc))
-                .addReg(NewReg);
+            MachineInstr *Drop =
+                BuildMI(MBB, InsertPt, MI.getDebugLoc(), TII->get(Opc))
+                    .addReg(NewReg);
+            // After the drop instruction, this reg operand will not be used
+            Drop->getOperand(0).setIsKill();
           } else {
             unsigned LocalId = getLocalId(Reg2Local, CurLocal, OldReg);
             unsigned Opc = getSetLocalOpcode(RC);
@@ -294,6 +297,9 @@ bool WebAssemblyExplicitLocals::runOnMachineFunction(MachineFunction &MF) {
                 .addReg(NewReg);
           }
           MI.getOperand(0).setReg(NewReg);
+          // This register operand is now being used by the inserted drop
+          // instruction, so make it undead.
+          MI.getOperand(0).setIsDead(false);
           MFI.stackifyVReg(NewReg);
           Changed = true;
         }