diff --git a/llvm/lib/CodeGen/MachineRegisterInfo.cpp b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
index 937f63f6c5e00..93f4235cc7e97 100644
--- a/llvm/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/llvm/lib/CodeGen/MachineRegisterInfo.cpp
@@ -448,9 +448,21 @@ void MachineRegisterInfo::clearKillFlags(Register Reg) const {
 }
 
 bool MachineRegisterInfo::isLiveIn(Register Reg) const {
-  for (const std::pair<MCRegister, Register> &LI : liveins())
+  for (const std::pair<MCRegister, Register> &LI : liveins()) {
     if ((Register)LI.first == Reg || LI.second == Reg)
       return true;
+
+    // Check if Reg is a subreg of live-in register
+    MCRegister PhysReg = LI.first;
+    if (!PhysReg.isValid() || !Reg.isPhysical())
+      continue;
+
+    const TargetRegisterInfo *TRI = getTargetRegisterInfo();
+    if (all_of(TRI->regunits(Reg), [&](const MCRegUnit RegUnit) {
+          return llvm::is_contained(TRI->regunits(PhysReg), RegUnit);
+        }))
+      return true;
+  }
   return false;
 }
 
diff --git a/llvm/test/CodeGen/AMDGPU/spill-partial-csr-sgpr-live-ins.mir b/llvm/test/CodeGen/AMDGPU/spill-partial-csr-sgpr-live-ins.mir
index ab960a7084528..834ae2f94538b 100644
--- a/llvm/test/CodeGen/AMDGPU/spill-partial-csr-sgpr-live-ins.mir
+++ b/llvm/test/CodeGen/AMDGPU/spill-partial-csr-sgpr-live-ins.mir
@@ -1,25 +1,6 @@
 # NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
-# RUN: not --crash llc -mtriple=amdgcn-amd-amdhsa -verify-machineinstrs -run-pass=si-lower-sgpr-spills %s -o /dev/null 2>&1 | FileCheck -check-prefix=VERIFIER %s
+# RUN: llc -mtriple=amdgcn-amd-amdhsa -verify-machineinstrs -run-pass=si-lower-sgpr-spills -o - %s| FileCheck %s
 
-# FIXME : Currently, MRI's liveIn check for registers does not take the corresponding live-in's sub-registers into account. As a result
-# in SILowerSGPRSpills, the SubReg spill gets marked KILLED even though its SuperReg is in the function Live-ins. This causes machine
-# verifier to now fail at direct usage of that SubReg, which intially should not be any problem before adding spill.
-
-# VERIFIER: After SI lower SGPR spill instructions
-
-# VERIFIER: *** Bad machine code: Using an undefined physical register ***
-# VERIFIER: - instruction: S_NOP 0, implicit $sgpr50
-# VERIFIER-NEXT: - operand 1:   implicit $sgpr50
-
-# VERIFIER: *** Bad machine code: Using an undefined physical register ***
-# VERIFIER: - instruction: S_NOP 0, implicit $sgpr52
-# VERIFIER-NEXT: - operand 1:   implicit $sgpr52
-
-# VERIFIER: *** Bad machine code: Using an undefined physical register ***
-# VERIFIER: - instruction: S_NOP 0, implicit $sgpr55
-# VERIFIER-NEXT: - operand 1:   implicit $sgpr55
-
-# VERIFIER: LLVM ERROR: Found 3 machine code errors. 
 ---
 name: spill_partial_live_csr_sgpr_test
 tracksRegLiveness: true
@@ -30,7 +11,22 @@ liveins:
 body:             |
   bb.0:
     liveins: $sgpr50_sgpr51, $sgpr52_sgpr53, $sgpr54_sgpr55
-
+    ; CHECK-LABEL: name: spill_partial_live_csr_sgpr_test
+    ; CHECK: liveins: $sgpr50, $sgpr52, $sgpr53, $sgpr54, $sgpr55, $sgpr56, $vgpr63, $sgpr50_sgpr51, $sgpr52_sgpr53, $sgpr54_sgpr55
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: $vgpr63 = SI_SPILL_S32_TO_VGPR $sgpr50, 0, $vgpr63
+    ; CHECK-NEXT: $vgpr63 = SI_SPILL_S32_TO_VGPR $sgpr52, 1, $vgpr63
+    ; CHECK-NEXT: $vgpr63 = SI_SPILL_S32_TO_VGPR $sgpr53, 2, $vgpr63
+    ; CHECK-NEXT: $vgpr63 = SI_SPILL_S32_TO_VGPR $sgpr54, 3, $vgpr63
+    ; CHECK-NEXT: $vgpr63 = SI_SPILL_S32_TO_VGPR $sgpr55, 4, $vgpr63
+    ; CHECK-NEXT: $vgpr63 = SI_SPILL_S32_TO_VGPR killed $sgpr56, 5, $vgpr63
+    ; CHECK-NEXT: S_NOP 0, implicit $sgpr50
+    ; CHECK-NEXT: $sgpr50 = S_MOV_B32 0
+    ; CHECK-NEXT: S_NOP 0, implicit $sgpr52
+    ; CHECK-NEXT: $sgpr52_sgpr53 = S_MOV_B64 0
+    ; CHECK-NEXT: S_NOP 0, implicit $sgpr55
+    ; CHECK-NEXT: $sgpr54_sgpr55 = S_MOV_B64 0
+    ; CHECK-NEXT: $sgpr56 = S_MOV_B32 0
     S_NOP 0, implicit $sgpr50
     $sgpr50 = S_MOV_B32 0
     S_NOP 0, implicit $sgpr52