diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index eb46124d9eb5f..caacacb7a7983 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -1398,7 +1398,9 @@ bool MachineInstr::isDead(const MachineRegisterInfo &MRI,
     Register Reg = MO.getReg();
     if (Reg.isPhysical()) {
       // Don't delete live physreg defs, or any reserved register defs.
-      if (!LivePhysRegs || !LivePhysRegs->available(Reg) || MRI.isReserved(Reg))
+      if ((!(MRI.tracksLiveness() && MO.isDead()) &&
+           (!LivePhysRegs || !LivePhysRegs->available(Reg))) ||
+          MRI.isReserved(Reg))
         return false;
     } else {
       if (MO.isDead())
diff --git a/llvm/test/CodeGen/RISCV/machine-sink.mir b/llvm/test/CodeGen/RISCV/machine-sink.mir
new file mode 100644
index 0000000000000..fb81c13300d51
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/machine-sink.mir
@@ -0,0 +1,113 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 6
+# RUN: llc -mtriple=riscv64 -run-pass machine-sink -sink-insts-to-avoid-spills -o - %s | FileCheck %s
+---
+name: no_delete_live_phys_def
+tracksRegLiveness: true
+body: |
+  ; CHECK-LABEL: name: no_delete_live_phys_def
+  ; CHECK: bb.0:
+  ; CHECK-NEXT:   successors: %bb.1(0x80000000)
+  ; CHECK-NEXT:   liveins: $x8
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   %x:gpr = COPY $x8
+  ; CHECK-NEXT:   %y:gpr = COPY %x, implicit-def $x8
+  ; CHECK-NEXT:   PseudoBR %bb.1
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.1:
+  ; CHECK-NEXT:   successors: %bb.1(0x80000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   %z:gpr = ADDI %y, 1
+  ; CHECK-NEXT:   PseudoBR %bb.1
+  bb.0:
+    liveins: $x8
+    %x:gpr = COPY $x8
+    %y:gpr = COPY %x, implicit-def $x8
+    PseudoBR %bb.1
+  bb.1:
+    %z:gpr = ADDI %y, 1
+    PseudoBR %bb.1
+...
+---
+name: delete_dead_phys_def
+tracksRegLiveness: true
+body: |
+  ; CHECK-LABEL: name: delete_dead_phys_def
+  ; CHECK: bb.0:
+  ; CHECK-NEXT:   successors: %bb.1(0x80000000)
+  ; CHECK-NEXT:   liveins: $x8
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   %x:gpr = COPY $x8
+  ; CHECK-NEXT:   PseudoBR %bb.1
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.1:
+  ; CHECK-NEXT:   successors: %bb.1(0x80000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[COPY:%[0-9]+]]:gpr = COPY %x, implicit-def dead $x8
+  ; CHECK-NEXT:   %z:gpr = ADDI [[COPY]], 1
+  ; CHECK-NEXT:   PseudoBR %bb.1
+  bb.0:
+    liveins: $x8
+    %x:gpr = COPY $x8
+    %y:gpr = COPY %x, implicit-def dead $x8
+    PseudoBR %bb.1
+  bb.1:
+    %z:gpr = ADDI %y, 1
+    PseudoBR %bb.1
+...
+---
+name: no_delete_dead_phys_def_no_tracksregliveness
+tracksRegLiveness: false
+body: |
+  ; CHECK-LABEL: name: no_delete_dead_phys_def_no_tracksregliveness
+  ; CHECK: bb.0:
+  ; CHECK-NEXT:   successors: %bb.1(0x80000000)
+  ; CHECK-NEXT:   liveins: $x8
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   %x:gpr = COPY $x8
+  ; CHECK-NEXT:   %y:gpr = COPY %x, implicit-def dead $x8
+  ; CHECK-NEXT:   PseudoBR %bb.1
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.1:
+  ; CHECK-NEXT:   successors: %bb.1(0x80000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[COPY:%[0-9]+]]:gpr = COPY %x, implicit-def dead $x8
+  ; CHECK-NEXT:   %z:gpr = ADDI [[COPY]], 1
+  ; CHECK-NEXT:   PseudoBR %bb.1
+  bb.0:
+    liveins: $x8
+    %x:gpr = COPY $x8
+    %y:gpr = COPY %x, implicit-def dead $x8
+    PseudoBR %bb.1
+  bb.1:
+    %z:gpr = ADDI %y, 1
+    PseudoBR %bb.1
+...
+---
+name: reserved_phys_def
+tracksRegLiveness: true
+body: |
+  ; CHECK-LABEL: name: reserved_phys_def
+  ; CHECK: bb.0:
+  ; CHECK-NEXT:   successors: %bb.1(0x80000000)
+  ; CHECK-NEXT:   liveins: $x8
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   %x:gpr = COPY $x8
+  ; CHECK-NEXT:   %y:gpr = COPY %x, implicit-def dead $x2
+  ; CHECK-NEXT:   PseudoBR %bb.1
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT: bb.1:
+  ; CHECK-NEXT:   successors: %bb.1(0x80000000)
+  ; CHECK-NEXT: {{  $}}
+  ; CHECK-NEXT:   [[COPY:%[0-9]+]]:gpr = COPY %x, implicit-def dead $x2
+  ; CHECK-NEXT:   %z:gpr = ADDI [[COPY]], 1
+  ; CHECK-NEXT:   PseudoBR %bb.1
+  bb.0:
+    liveins: $x8
+    %x:gpr = COPY $x8
+    %y:gpr = COPY %x, implicit-def dead $x2
+    PseudoBR %bb.1
+
+  bb.1:
+    %z:gpr = ADDI %y, 1
+    PseudoBR %bb.1
+...