diff --git a/llvm/lib/CodeGen/MachineCopyPropagation.cpp b/llvm/lib/CodeGen/MachineCopyPropagation.cpp
--- a/llvm/lib/CodeGen/MachineCopyPropagation.cpp
+++ b/llvm/lib/CodeGen/MachineCopyPropagation.cpp
@@ -109,6 +109,7 @@
   struct CopyInfo {
     MachineInstr *MI, *LastSeenUseInCopy;
     SmallVector<MCRegister, 4> DefRegs;
+    SmallVector<MCRegister, 4> SrcRegs;
     bool Avail;
   };
 
@@ -151,6 +152,8 @@
         }
         RegsToInvalidate.insert(I->second.DefRegs.begin(),
                                 I->second.DefRegs.end());
+        RegsToInvalidate.insert(I->second.SrcRegs.begin(),
+                                I->second.SrcRegs.end());
       }
     }
     for (MCRegister InvalidReg : RegsToInvalidate)
@@ -167,6 +170,7 @@
         // When we clobber the source of a copy, we need to clobber everything
         // it defined.
         markRegsUnavailable(I->second.DefRegs, TRI);
+        markRegsUnavailable(I->second.SrcRegs, TRI);
         // When we clobber the destination of a copy, we need to clobber the
         // whole register it defined.
         if (MachineInstr *MI = I->second.MI) {
@@ -193,15 +197,17 @@
 
     // Remember Def is defined by the copy.
     for (MCRegUnit Unit : TRI.regunits(Def))
-      Copies[Unit] = {MI, nullptr, {}, true};
+      Copies[Unit] = {MI, nullptr, {}, {}, true};
 
     // Remember source that's copied to Def. Once it's clobbered, then
     // it's no longer available for copy propagation.
     for (MCRegUnit Unit : TRI.regunits(Src)) {
-      auto I = Copies.insert({Unit, {nullptr, nullptr, {}, false}});
+      auto I = Copies.insert({Unit, {nullptr, nullptr, {}, {}, false}});
       auto &Copy = I.first->second;
       if (!is_contained(Copy.DefRegs, Def))
         Copy.DefRegs.push_back(Def);
+      if (!is_contained(Copy.SrcRegs, Src))
+        Copy.SrcRegs.push_back(Src);
       Copy.LastSeenUseInCopy = MI;
     }
   }
diff --git a/llvm/test/CodeGen/AMDGPU/mcp-use-before-def.mir b/llvm/test/CodeGen/AMDGPU/mcp-use-before-def.mir
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/mcp-use-before-def.mir
@@ -0,0 +1,28 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 2
+# RUN: llc -mtriple=amdgcn-amd-amdhsa -verify-machineinstrs  -run-pass=machine-cp -o - %s | FileCheck %s
+
+# machine copy prop should not introduce use before def
+---
+name: back_copy_block
+body:           |
+  bb.0:
+    ; CHECK-LABEL: name: back_copy_block
+    ; CHECK: $vgpr20_vgpr21_vgpr22_vgpr23 = IMPLICIT_DEF
+    ; CHECK-NEXT: $vgpr10_vgpr11_vgpr12_vgpr13 = IMPLICIT_DEF
+    ; CHECK-NEXT: renamable $vgpr0_vgpr1 = V_MOV_B64_e64 killed $vgpr20_vgpr21, implicit $exec
+    ; CHECK-NEXT: renamable $vgpr20 = V_MOV_B32_e32 killed $vgpr1, implicit $exec
+    ; CHECK-NEXT: renamable $vgpr6_vgpr7_vgpr8_vgpr9 = COPY renamable $vgpr10_vgpr11_vgpr12_vgpr13
+    ; CHECK-NEXT: renamable $vgpr20 = V_MOV_B32_e32 killed $vgpr6, implicit $exec
+    ; CHECK-NEXT: S_ENDPGM 0, amdgpu_allvgprs
+    $vgpr20_vgpr21_vgpr22_vgpr23 = IMPLICIT_DEF
+    $vgpr10_vgpr11_vgpr12_vgpr13 = IMPLICIT_DEF
+    renamable $vgpr0_vgpr1 = V_MOV_B64_e64 killed renamable $vgpr20_vgpr21, implicit $exec
+    renamable $vgpr20 = V_MOV_B32_e32 killed renamable $vgpr1, implicit $exec
+    renamable $vgpr6_vgpr7_vgpr8_vgpr9 = COPY killed renamable $vgpr10_vgpr11_vgpr12_vgpr13
+    renamable $vgpr14_vgpr15 = COPY killed renamable $vgpr0_vgpr1
+    renamable $vgpr20 = V_MOV_B32_e32 killed renamable $vgpr6, implicit $exec
+    renamable $vgpr1_vgpr2_vgpr3_vgpr4 = COPY killed renamable $vgpr6_vgpr7_vgpr8_vgpr9
+    S_ENDPGM 0, amdgpu_allvgprs
+...
+## NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
+# CHECK: {{.*}}