diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.cpp
--- a/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyDebugValueManager.cpp
@@ -226,6 +226,15 @@
   return true;
 }
 
+// Returns true if any instruction in MBB has the same debug locatio as DL.
+// Also returns true if DL is an empty location.
+static bool hasSameDebugLoc(const MachineBasicBlock *MBB, DebugLoc DL) {
+  for (const auto &MI : *MBB)
+    if (MI.getDebugLoc() == DL)
+      return true;
+  return false;
+}
+
 // Sink 'Def', and also sink its eligible DBG_VALUEs to the place before
 // 'Insert'. Convert the original DBG_VALUEs into undefs.
 //
@@ -263,6 +272,12 @@
       getSinkableDebugValues(Insert);
 
   // Sink Def first.
+  //
+  // When moving to a different BB, we preserve the debug loc only if the
+  // destination BB contains the same location. See
+  // https://llvm.org/docs/HowToUpdateDebugInfo.html#when-to-preserve-an-instruction-location.
+  if (Def->getParent() != MBB && !hasSameDebugLoc(MBB, Def->getDebugLoc()))
+      Def->setDebugLoc(DebugLoc());
   MBB->splice(Insert, Def->getParent(), Def);
 
   if (DbgValues.empty())
@@ -344,6 +359,11 @@
   // Clone Def first.
   if (CloneDef) {
     MachineInstr *Clone = MF->CloneMachineInstr(Def);
+    // When cloning to a different BB, we preserve the debug loc only if the
+    // destination BB contains the same location. See
+    // https://llvm.org/docs/HowToUpdateDebugInfo.html#when-to-preserve-an-instruction-location.
+    if (Def->getParent() != MBB && !hasSameDebugLoc(MBB, Def->getDebugLoc()))
+      Clone->setDebugLoc(DebugLoc());
     if (NewReg != CurrentReg && NewReg.isValid())
       Clone->getOperand(0).setReg(NewReg);
     MBB->insert(Insert, Clone);
diff --git a/llvm/test/DebugInfo/WebAssembly/dbg-loc-reg-stackify.mir b/llvm/test/DebugInfo/WebAssembly/dbg-loc-reg-stackify.mir
new file mode 100644
--- /dev/null
+++ b/llvm/test/DebugInfo/WebAssembly/dbg-loc-reg-stackify.mir
@@ -0,0 +1,125 @@
+# RUN: llc -run-pass wasm-reg-stackify %s -o - | FileCheck %s
+
+--- |
+  target triple = "wasm32-unknown-unknown"
+
+  declare void @use(i32)
+
+  define void @sink_same_bb() {
+    unreachable
+  }
+  define void @clone_same_bb() {
+    unreachable
+  }
+  define void @clone_different_bb_0() {
+    unreachable
+  }
+  define void @clone_different_bb_1() {
+    unreachable
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!2, !3, !4}
+
+  !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, emissionKind: FullDebug)
+  !1 = !DIFile(filename: "test.c", directory: "")
+  !2 = !{i32 7, !"Dwarf Version", i32 5}
+  !3 = !{i32 2, !"Debug Info Version", i32 3}
+  !4 = !{i32 1, !"wchar_size", i32 4}
+  !6 = distinct !DISubprogram(name: "sink_same_bb", scope: !1, file: !1, line: 1, type: !7, scopeLine: 1, unit: !0)
+  !7 = !DISubroutineType(types: !8)
+  !8 = !{null}
+...
+
+---
+# Sinking within the same BB preserves the debug location.
+# CHECK-LABEL: name: sink_same_bb
+name: sink_same_bb
+liveins:
+  - { reg: '$arguments' }
+tracksRegLiveness: true
+body: |
+  bb.0:
+    liveins: $arguments
+    %0:i32 = CONST_I32 1, implicit-def $arguments, debug-location !DILocation(line:10, scope:!6)
+    NOP implicit-def $arguments
+    CALL @use, %0:i32, implicit-def $arguments
+    RETURN implicit-def $arguments
+
+  ; CHECK:      %0:i32 = CONST_I32 1, {{.*}}, debug-location !DILocation(line: 10
+  ; CHECK-NEXT: CALL @use
+...
+
+---
+# Cloning within the same BB preserves the debug location.
+# CHECK-LABEL: name: clone_same_bb
+name: clone_same_bb
+liveins:
+  - { reg: '$arguments' }
+tracksRegLiveness: true
+body: |
+  bb.0:
+    liveins: $arguments
+    %0:i32 = CONST_I32 1, implicit-def $arguments, debug-location !DILocation(line:10, scope:!6)
+    NOP implicit-def $arguments
+    CALL @use, %0:i32, implicit-def $arguments
+    CALL @use, %0:i32, implicit-def $arguments
+    RETURN implicit-def $arguments
+
+  ; CHECK:      CALL @use
+  ; CHECK-NEXT: %1:i32 = CONST_I32 1, {{.*}}, debug-location !DILocation(line: 10
+  ; CHECK-NEXT: CALL @use
+...
+
+---
+# Cloning to a different BB preserves the debug location in this case because
+# the destination BB has an instruction that has the same debug location
+# (test.c:10).
+# CHECK-LABEL: name: clone_different_bb_0
+name: clone_different_bb_0
+liveins:
+  - { reg: '$arguments' }
+tracksRegLiveness: true
+body: |
+  bb.0:
+    successors: %bb.1
+    liveins: $arguments
+    %0:i32 = CONST_I32 1, implicit-def $arguments, debug-location !DILocation(line:10, scope:!6)
+    BR %bb.1, implicit-def $arguments
+
+  bb.1:
+  ; predecessors: %bb.0
+    CALL @use, %0:i32, implicit-def $arguments, debug-location !DILocation(line:10, scope:!6)
+    RETURN implicit-def $arguments
+
+  ; CHECK: bb.1:
+  ; CHECK:      %1:i32 = CONST_I32 1, {{.*}}, debug-location !DILocation(line: 10
+  ; CHECK-NEXT: CALL @use, %1, {{.*}}, debug-location !DILocation(line: 10
+...
+
+---
+# Cloning to a different BB does NOT preserve the debug location in this case
+# because the destination BB doesn't have an instruction that has the same debug
+# location (It has test.c:20 but not test.c:10).
+# CHECK-LABEL: name: clone_different_bb_1
+name: clone_different_bb_1
+liveins:
+  - { reg: '$arguments' }
+tracksRegLiveness: true
+body: |
+  bb.0:
+    successors: %bb.1
+    liveins: $arguments
+    %0:i32 = CONST_I32 1, implicit-def $arguments, debug-location !DILocation(line:10, scope:!6)
+    BR %bb.1, implicit-def $arguments
+
+  bb.1:
+  ; predecessors: %bb.0
+    CALL @use, %0:i32, implicit-def $arguments, debug-location !DILocation(line:20, scope:!6)
+    RETURN implicit-def $arguments
+
+  ; CHECK: bb.1:
+  ; CHECK:      %1:i32 = CONST_I32 1
+  ; CHECK-NOT:  %1:i32 = CONST_I32 1, {{.*}}, debug-location !DILocation(line: 10
+  ; CHECK-NEXT: CALL @use, %1, {{.*}}, debug-location !DILocation(line: 20
+...