diff --git a/llvm/lib/CodeGen/MachineOutliner.cpp b/llvm/lib/CodeGen/MachineOutliner.cpp
--- a/llvm/lib/CodeGen/MachineOutliner.cpp
+++ b/llvm/lib/CodeGen/MachineOutliner.cpp
@@ -798,6 +798,7 @@
                  Last = std::next(CallInst.getReverse());
              Iter != Last; Iter++) {
           MachineInstr *MI = &*Iter;
+          SmallSet<Register, 2> InstrUseRegs;
           for (MachineOperand &MOP : MI->operands()) {
             // Skip over anything that isn't a register.
             if (!MOP.isReg())
@@ -806,7 +807,7 @@
             if (MOP.isDef()) {
               // Introduce DefRegs set to skip the redundant register.
               DefRegs.insert(MOP.getReg());
-              if (!MOP.isDead() && UseRegs.count(MOP.getReg()))
+              if (!MOP.isDead() && UseRegs.count(MOP.getReg()) && !InstrUseRegs.count(MOP.getReg()))
                 // Since the regiester is modeled as defined,
                 // it is not necessary to be put in use register set.
                 UseRegs.erase(MOP.getReg());
@@ -814,6 +815,7 @@
               // Any register which is not undefined should
               // be put in the use register set.
               UseRegs.insert(MOP.getReg());
+              InstrUseRegs.insert(MOP.getReg());
             }
           }
           if (MI->isCandidateForCallSiteEntry())
diff --git a/llvm/test/CodeGen/AArch64/machine-outliner-side-effect.mir b/llvm/test/CodeGen/AArch64/machine-outliner-side-effect-3.mir
copy from llvm/test/CodeGen/AArch64/machine-outliner-side-effect.mir
copy to llvm/test/CodeGen/AArch64/machine-outliner-side-effect-3.mir
--- a/llvm/test/CodeGen/AArch64/machine-outliner-side-effect.mir
+++ b/llvm/test/CodeGen/AArch64/machine-outliner-side-effect-3.mir
@@ -1,6 +1,6 @@
 # RUN: llc -mtriple=aarch64 -run-pass=machine-outliner -verify-machineinstrs %s -o - | FileCheck %s
 
-# The test checks whether the compiler updates the side effect of function @OUTLINED_FUNCTION_0 by adding the use of register x20.
+# The test checks whether the compiler updates the side effect of function @OUTLINED_FUNCTION_0 when passing register x0.
 
 --- |
   declare void @spam() local_unnamed_addr
@@ -11,17 +11,17 @@
 tracksRegLiveness: true
 body:             |
   bb.0:
-    liveins: $x0, $x20
+    liveins: $x0
 
-    $x0 = COPY renamable $x20
+    $w1 = MOVZWi 0, 0
     BL @spam, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp, implicit-def $x0
     renamable $x21 = COPY $x0
 
-    $x0 = COPY renamable $x20
+    $w1 = MOVZWi 0, 0
     BL @spam, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp, implicit-def $x0
     renamable $x22 = COPY $x0
 
-    $x0 = COPY killed renamable $x20
+    $w1 = MOVZWi 0, 0
     BL @spam, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp, implicit-def $x0
     renamable $x3 = COPY $x0
 
@@ -29,4 +29,4 @@
 
 ...
 
-# CHECK: BL @OUTLINED_FUNCTION_0, {{.*}}, implicit $x20, {{.*}}
+# CHECK: BL @OUTLINED_FUNCTION_0, {{.*}}, implicit $x0{{.*}}
diff --git a/llvm/test/CodeGen/AArch64/machine-outliner-side-effect.mir b/llvm/test/CodeGen/AArch64/machine-outliner-side-effect.mir
--- a/llvm/test/CodeGen/AArch64/machine-outliner-side-effect.mir
+++ b/llvm/test/CodeGen/AArch64/machine-outliner-side-effect.mir
@@ -29,4 +29,4 @@
 
 ...
 
-# CHECK: BL @OUTLINED_FUNCTION_0, {{.*}}, implicit $x20, {{.*}}
+# CHECK: BL @OUTLINED_FUNCTION_0, {{.*}}, implicit $x20{{.*}}