Index: llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
===================================================================
--- llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
+++ llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
@@ -587,7 +587,7 @@
   }
 
   for (unsigned Reg : RegClassInfo.getOrder(&RegClass))
-    if (!LiveRegs.contains(Reg))
+    if (LiveRegs.available(MF->getRegInfo(), Reg))
       return Reg;
   return 0;
 }
Index: llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
===================================================================
--- llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
+++ llvm/lib/Target/ARM/Thumb1FrameLowering.cpp
@@ -582,10 +582,10 @@
 static void findTemporariesForLR(const BitVector &GPRsNoLRSP,
                                  const BitVector &PopFriendly,
                                  const LivePhysRegs &UsedRegs, unsigned &PopReg,
-                                 unsigned &TmpReg) {
+                                 unsigned &TmpReg, MachineRegisterInfo &MRI) {
   PopReg = TmpReg = 0;
   for (auto Reg : GPRsNoLRSP.set_bits()) {
-    if (!UsedRegs.contains(Reg)) {
+    if (UsedRegs.available(MRI, Reg)) {
       // Remember the first pop-friendly register and exit.
       if (PopFriendly.test(Reg)) {
         PopReg = Reg;
@@ -693,7 +693,8 @@
   GPRsNoLRSP.reset(ARM::LR);
   GPRsNoLRSP.reset(ARM::SP);
   GPRsNoLRSP.reset(ARM::PC);
-  findTemporariesForLR(GPRsNoLRSP, PopFriendly, UsedRegs, PopReg, TemporaryReg);
+  findTemporariesForLR(GPRsNoLRSP, PopFriendly, UsedRegs, PopReg, TemporaryReg,
+                       MF.getRegInfo());
 
   // If we couldn't find a pop-friendly register, try restoring LR before
   // popping the other callee-saved registers, so we could use one of them as a
@@ -704,7 +705,8 @@
     PrevMBBI--;
     if (PrevMBBI->getOpcode() == ARM::tPOP) {
       UsedRegs.stepBackward(*PrevMBBI);
-      findTemporariesForLR(GPRsNoLRSP, PopFriendly, UsedRegs, PopReg, TemporaryReg);
+      findTemporariesForLR(GPRsNoLRSP, PopFriendly, UsedRegs, PopReg,
+                           TemporaryReg, MF.getRegInfo());
       if (PopReg) {
         MBBI = PrevMBBI;
         UseLDRSP = true;
Index: llvm/test/CodeGen/Thumb/PR35481.ll
===================================================================
--- llvm/test/CodeGen/Thumb/PR35481.ll
+++ llvm/test/CodeGen/Thumb/PR35481.ll
@@ -18,10 +18,11 @@
 ; CHECK-V4T-NEXT:    movs r2, #3
 ; CHECK-V4T-NEXT:    movs r3, #4
 ; CHECK-V4T-NEXT:    bl g
-; CHECK-V4T-NEXT:    ldr r7, [sp, #4]
-; CHECK-V4T-NEXT:    mov lr, r7
 ; CHECK-V4T-NEXT:    pop {r7}
-; CHECK-V4T-NEXT:    add sp, #4
+; CHECK-V4T-NEXT:    mov r12, r0
+; CHECK-V4T-NEXT:    pop {r0}
+; CHECK-V4T-NEXT:    mov lr, r0
+; CHECK-V4T-NEXT:    mov r0, r12
 ; CHECK-V4T-NEXT:    bx lr
 ;
 ; CHECK-V8M-LABEL: f:
@@ -35,10 +36,11 @@
 ; CHECK-V8M-NEXT:    movs r1, #2
 ; CHECK-V8M-NEXT:    movs r2, #3
 ; CHECK-V8M-NEXT:    movs r3, #4
-; CHECK-V8M-NEXT:    ldr r7, [sp, #4]
-; CHECK-V8M-NEXT:    mov lr, r7
 ; CHECK-V8M-NEXT:    pop {r7}
-; CHECK-V8M-NEXT:    add sp, #4
+; CHECK-V8M-NEXT:    mov r12, r0
+; CHECK-V8M-NEXT:    pop {r0}
+; CHECK-V8M-NEXT:    mov lr, r0
+; CHECK-V8M-NEXT:    mov r0, r12
 ; CHECK-V8M-NEXT:    b g
 entry:
   %call = tail call i32 @h(i32 1)