1 files changed, 19 insertions, 0 deletions
diff --git a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
index e69fa32..2ab7bf1 100644
--- a/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
+++ b/llvm/lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
@@ -1386,6 +1386,25 @@ AArch64LoadStoreOpt::mergePairedInsns(MachineBasicBlock::iterator I,
       if (MOP.isReg() && MOP.isKill())
         DefinedInBB.addReg(MOP.getReg());
 
+  // Copy over any implicit-def operands. This is like MI.copyImplicitOps, but
+  // only copies implicit defs and makes sure that each operand is only added
+  // once in case of duplicates.
+  auto CopyImplicitOps = [&](MachineBasicBlock::iterator MI1,
+                             MachineBasicBlock::iterator MI2) {
+    SmallSetVector<Register, 4> Ops;
+    for (const MachineOperand &MO :
+         llvm::drop_begin(MI1->operands(), MI1->getDesc().getNumOperands()))
+      if (MO.isReg() && MO.isImplicit() && MO.isDef())
+        Ops.insert(MO.getReg());
+    for (const MachineOperand &MO :
+         llvm::drop_begin(MI2->operands(), MI2->getDesc().getNumOperands()))
+      if (MO.isReg() && MO.isImplicit() && MO.isDef())
+        Ops.insert(MO.getReg());
+    for (auto Op : Ops)
+      MIB.addDef(Op, RegState::Implicit);
+  };
+  CopyImplicitOps(I, Paired);
+
   // Erase the old instructions.
   I->eraseFromParent();
   Paired->eraseFromParent();