Index: llvm/lib/CodeGen/MachineOutliner.cpp
===================================================================
--- llvm/lib/CodeGen/MachineOutliner.cpp
+++ llvm/lib/CodeGen/MachineOutliner.cpp
@@ -56,6 +56,7 @@
 //===----------------------------------------------------------------------===//
 #include "llvm/CodeGen/MachineOutliner.h"
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/CodeGen/MachineFunction.h"
@@ -1248,28 +1249,41 @@
         // Helper lambda for adding implicit def operands to the call
         // instruction. It also updates call site information for moved
         // code.
-        auto CopyDefsAndUpdateCalls = [&CallInst](MachineInstr &MI) {
-          for (MachineOperand &MOP : MI.operands()) {
+        SmallSet<unsigned, 2> UseRegs;
+        MachineBasicBlock::reverse_iterator Last =
+            std::next(CallInst.getReverse());
+        MachineBasicBlock::reverse_iterator Iter = EndIt.getReverse();
+        // Copy over the defs in the outlined range.
+        // First inst in outlined range <-- Anything that's defined in this
+        // ...                           .. range has to be added as an
+        // implicit Last inst in outlined range  <-- def to the call
+        // instruction. Also remove call site information for outlined block
+        // of code. The exposed uses need to be copied in the outlined range.
+        for (; Iter != Last; Iter++) {
+          MachineInstr *MI = &*Iter;
+          for (MachineOperand &MOP : MI->operands()) {
             // Skip over anything that isn't a register.
             if (!MOP.isReg())
               continue;
 
             // If it's a def, add it to the call instruction.
-            if (MOP.isDef())
+            if (MOP.isDef()) {
               CallInst->addOperand(MachineOperand::CreateReg(
                   MOP.getReg(), true, /* isDef = true */
                   true /* isImp = true */));
+              if (UseRegs.count(MOP.getReg()))
+                UseRegs.erase(MOP.getReg());
+            } else if (!MOP.isUndef())
+              UseRegs.insert(MOP.getReg());
           }
-          if (MI.shouldUpdateCallSiteInfo())
-            MI.getMF()->eraseCallSiteInfo(&MI);
+          if (MI->shouldUpdateCallSiteInfo())
+            MI->getMF()->eraseCallSiteInfo(MI);
         };
-        // Copy over the defs in the outlined range.
-        // First inst in outlined range <-- Anything that's defined in this
-        // ...                           .. range has to be added as an
-        // implicit Last inst in outlined range  <-- def to the call
-        // instruction. Also remove call site information for outlined block
-        // of code.
-        std::for_each(CallInst, std::next(EndIt), CopyDefsAndUpdateCalls);
+        for (auto I : UseRegs)
+          // If it's a exposed use, add it to the call instruction.
+          CallInst->addOperand(
+              MachineOperand::CreateReg(I, false, /* isDef = false */
+                                        true /* isImp = true */));
       }
 
       // Erase from the point after where the call was inserted up to, and
Index: llvm/test/CodeGen/AArch64/machine-outliner-noreturn-save-lr.mir
===================================================================
--- llvm/test/CodeGen/AArch64/machine-outliner-noreturn-save-lr.mir
+++ llvm/test/CodeGen/AArch64/machine-outliner-noreturn-save-lr.mir
@@ -27,7 +27,7 @@
     ; CHECK-LABEL: name: save_lr_1
     ; CHECK: liveins: $lr
     ; CHECK: $x0 = ORRXrs $xzr, $lr, 0
-    ; CHECK: BL @OUTLINED_FUNCTION_0, implicit-def $lr, implicit $sp, implicit-def $lr, implicit-def $lr, implicit-def $w3, implicit-def $w4, implicit-def $w5, implicit-def $w6
+    ; CHECK: BL @OUTLINED_FUNCTION_0, implicit-def $lr, implicit $sp, implicit-def $lr, implicit-def $w3, implicit-def $w4, implicit-def $w5, implicit-def $w6, implicit $sp, implicit $wzr, implicit $xzr, implicit $x0
     ; CHECK: $lr = ORRXrs $xzr, $x0, 0
     $w3 = ORRWri $wzr, 1
     $w4 = ORRWri $wzr, 1
@@ -49,7 +49,7 @@
     ; CHECK-LABEL: name: save_lr_2
     ; CHECK: liveins: $lr
     ; CHECK: $x0 = ORRXrs $xzr, $lr, 0
-    ; CHECK: BL @OUTLINED_FUNCTION_0, implicit-def $lr, implicit $sp, implicit-def $lr, implicit-def $lr, implicit-def $w3, implicit-def $w4, implicit-def $w5, implicit-def $w6
+    ; CHECK: BL @OUTLINED_FUNCTION_0, implicit-def $lr, implicit $sp, implicit-def $lr, implicit-def $w3, implicit-def $w4, implicit-def $w5, implicit-def $w6, implicit $sp, implicit $wzr, implicit $xzr, implicit $x0
     ; CHECK: $lr = ORRXrs $xzr, $x0, 0
     $w3 = ORRWri $wzr, 1
     $w4 = ORRWri $wzr, 1
@@ -71,7 +71,7 @@
     ; CHECK-LABEL: name: save_lr_3
     ; CHECK: liveins: $lr
     ; CHECK: $x0 = ORRXrs $xzr, $lr, 0
-    ; CHECK: BL @OUTLINED_FUNCTION_0, implicit-def $lr, implicit $sp, implicit-def $lr, implicit-def $lr, implicit-def $w3, implicit-def $w4, implicit-def $w5, implicit-def $w6
+    ; CHECK: BL @OUTLINED_FUNCTION_0, implicit-def $lr, implicit $sp, implicit-def $lr, implicit-def $w3, implicit-def $w4, implicit-def $w5, implicit-def $w6, implicit $sp, implicit $wzr, implicit $xzr, implicit $x0
     ; CHECK: $lr = ORRXrs $xzr, $x0, 0
     $w3 = ORRWri $wzr, 1
     $w4 = ORRWri $wzr, 1
@@ -93,7 +93,7 @@
     ; CHECK-LABEL: name: save_lr_4
     ; CHECK: liveins: $lr
     ; CHECK: $x0 = ORRXrs $xzr, $lr, 0
-    ; CHECK: BL @OUTLINED_FUNCTION_0, implicit-def $lr, implicit $sp, implicit-def $lr, implicit-def $lr, implicit-def $w3, implicit-def $w4, implicit-def $w5, implicit-def $w6
+    ; CHECK: BL @OUTLINED_FUNCTION_0, implicit-def $lr, implicit $sp, implicit-def $lr, implicit-def $w3, implicit-def $w4, implicit-def $w5, implicit-def $w6, implicit $sp, implicit $wzr, implicit $xzr, implicit $x0
     ; CHECK: $lr = ORRXrs $xzr, $x0, 0
     $w3 = ORRWri $wzr, 1
     $w4 = ORRWri $wzr, 1
Index: llvm/test/CodeGen/AArch64/machine-outliner-side-effect.mir
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/AArch64/machine-outliner-side-effect.mir
@@ -0,0 +1,32 @@
+# 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.
+
+--- |
+  declare void @spam() local_unnamed_addr
+  define void @baz() optsize minsize noredzone { ret void }
+...
+---
+name:            baz
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $x0, $x20
+
+    $x0 = COPY renamable $x20
+    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
+    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
+    BL @spam, csr_aarch64_aapcs, implicit-def dead $lr, implicit $sp, implicit $x0, implicit-def $sp, implicit-def $x0
+    renamable $x3 = COPY $x0
+
+    RET_ReallyLR
+
+...
+
+# CHECK: BL @OUTLINED_FUNCTION_0, {{.*}}, implicit $x20, {{.*}}