Index: lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
===================================================================
--- lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
+++ lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
@@ -309,6 +309,8 @@
   // Local expression tree should go after the BLOCK.
   for (auto I = Header->getFirstTerminator(), E = Header->begin(); I != E;
        --I) {
+    if (std::prev(I)->isDebugInstr() || std::prev(I)->isPosition())
+      continue;
     if (WebAssembly::isChild(*std::prev(I), MFI))
       AfterSet.insert(&*std::prev(I));
     else
@@ -531,6 +533,8 @@
   // Local expression tree should go after the TRY.
   for (auto I = Header->getFirstTerminator(), E = Header->begin(); I != E;
        --I) {
+    if (std::prev(I)->isDebugInstr() || std::prev(I)->isPosition())
+      continue;
     if (WebAssembly::isChild(*std::prev(I), MFI))
       AfterSet.insert(&*std::prev(I));
     else
Index: test/CodeGen/WebAssembly/cfg-stackify-dbg-skip.ll
===================================================================
--- /dev/null
+++ test/CodeGen/WebAssembly/cfg-stackify-dbg-skip.ll
@@ -0,0 +1,57 @@
+; RUN: llc %s -O2 -stop-before wasm-cfg-stackify -o - | FileCheck -check-prefix=CHECK-BEFORE %s
+; RUN: llc %s -O2 -stop-after wasm-cfg-stackify -o - | FileCheck -check-prefix=CHECK-AFTER %s
+
+; The test checks if "block" instruction was not inserted inside group of
+; of instructions that form a stackified expression. In this case, the test
+; instructions contain DBG_VALUE between them.
+
+; CHECK-BEFORE: body:
+; CHECK-BEFORE: GET_LOCAL_I64
+; CHECK-BEFORE-NEXT: I32_WRAP_I64
+; CHECK-BEFORE-NEXT: DBG_VALUE
+; CHECK-BEFORE-NEXT: BR_UNLESS
+
+; CHECK-AFTER: body:
+; CHECK-AFTER: BLOCK
+; CHECK-AFTER-NEXT: GET_LOCAL_I64
+; CHECK-AFTER-NEXT: I32_WRAP_I64
+; CHECK-AFTER-NEXT: DBG_VALUE
+; CHECK-AFTER-NEXT: BR_UNLESS
+
+target triple = "wasm32-unknown-unknown"
+define {}* @foo({ i8*, i32 }* nocapture, i32, i64) local_unnamed_addr #0 {
+start:
+  %tmp.sroa.0.0.extract.trunc.i.i.i.i.i = trunc i64 %2 to i32
+  %3 = icmp eq i32 %tmp.sroa.0.0.extract.trunc.i.i.i.i.i, 0
+  br i1 %3, label %bb9, label %bb2
+bb2:                                              ; preds = %start
+  call void @llvm.dbg.value(metadata i32 %tmp.sroa.0.0.extract.trunc.i.i.i.i.i, metadata !46, metadata !DIExpression(DW_OP_LLVM_fragment, 0, 32)), !dbg !105
+  %4 = tail call i8* @malloc(i32 8)
+  %5 = getelementptr inbounds i8, i8* %4, i32 4
+  %6 = bitcast i8* %5 to i32*
+  %7 = bitcast i8* %4 to {}*
+  br label %bb9
+bb9:                                              ; preds = %bb2, %start
+  %data.sroa.0.0 = phi {}* [ %7, %bb2 ], [ inttoptr (i32 1 to {}*), %start ]
+  ret {}* %data.sroa.0.0
+}
+declare noalias i8* @malloc(i32) unnamed_addr #0
+declare void @llvm.dbg.value(metadata, metadata, metadata) #1
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!33}
+!0 = distinct !DICompileUnit(language: DW_LANG_Rust, file: !6, producer: "clang LLVM (rustc version 1.30.0-dev)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3)
+!2 = !{}
+!3 = !{}
+!6 = !DIFile(filename: "<unknown>", directory: "")
+!22 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "&str", file: !6, size: 64, align: 32, elements: !23, identifier: "111094d970b097647de579f9c509ef08")
+!23 = !{}
+!33 = !{i32 2, !"Debug Info Version", i32 3}
+!35 = distinct !DILexicalBlock(scope: !37, file: !6, line: 357, column: 8)
+!37 = distinct !DISubprogram(name: "foobar", linkageName: "_fooba", scope: !38, file: !6, line: 353, type: !39, isLocal: true, isDefinition: true, scopeLine: 353, flags: DIFlagPrototyped, isOptimized: true, unit: !0, templateParams: !47, retainedNodes: !42)
+!38 = !DINamespace(name: "ptr", scope: null)
+!39 = !DISubroutineType(types: !40)
+!40 = !{}
+!42 = !{!46}
+!46 = !DILocalVariable(name: "z", scope: !35, file: !6, line: 357, type: !22, align: 4)
+!47 = !{}
+!105 = !DILocation(line: 357, column: 12, scope: !35)