diff --git a/llvm/lib/Transforms/Scalar/ADCE.cpp b/llvm/lib/Transforms/Scalar/ADCE.cpp
index f3ad95560804..d94f83d66c45 100644
--- a/llvm/lib/Transforms/Scalar/ADCE.cpp
+++ b/llvm/lib/Transforms/Scalar/ADCE.cpp
@@ -22,6 +22,7 @@
 #include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/CFG.h"
+#include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/InstIterator.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
@@ -33,22 +34,55 @@ using namespace llvm;
 
 STATISTIC(NumRemoved, "Number of instructions removed");
 
+static void collectLiveScopes(const DILocalScope &LS,
+                              SmallPtrSetImpl<const Metadata *> &AliveScopes) {
+  if (!AliveScopes.insert(&LS).second)
+    return;
+
+  if (isa<DISubprogram>(LS))
+    return;
+
+  // Tail-recurse through the scope chain.
+  collectLiveScopes(cast<DILocalScope>(*LS.getScope()), AliveScopes);
+}
+
+static void collectLiveScopes(const DILocation &DL,
+                              SmallPtrSetImpl<const Metadata *> &AliveScopes) {
+  // Even though DILocations are not scopes, shove them into AliveScopes so we
+  // don't revisit them.
+  if (!AliveScopes.insert(&DL).second)
+    return;
+
+  // Collect live scopes from the scope chain.
+  collectLiveScopes(*DL.getScope(), AliveScopes);
+
+  // Tail-recurse through the inlined-at chain.
+  if (const DILocation *IA = DL.getInlinedAt())
+    collectLiveScopes(*IA, AliveScopes);
+}
+
 static bool aggressiveDCE(Function& F) {
   SmallPtrSet<Instruction*, 32> Alive;
   SmallVector<Instruction*, 128> Worklist;
 
   // Collect the set of "root" instructions that are known live.
   for (Instruction &I : instructions(F)) {
-    if (isa<TerminatorInst>(I) || isa<DbgInfoIntrinsic>(I) || I.isEHPad() ||
-        I.mayHaveSideEffects()) {
+    if (isa<TerminatorInst>(I) || I.isEHPad() || I.mayHaveSideEffects()) {
       Alive.insert(&I);
       Worklist.push_back(&I);
     }
   }
 
-  // Propagate liveness backwards to operands.
+  // Propagate liveness backwards to operands.  Keep track of live debug info
+  // scopes.
+  SmallPtrSet<const Metadata *, 32> AliveScopes;
   while (!Worklist.empty()) {
     Instruction *Curr = Worklist.pop_back_val();
+
+    // Collect the live debug info scopes attached to this instruction.
+    if (const DILocation *DL = Curr->getDebugLoc())
+      collectLiveScopes(*DL, AliveScopes);
+
     for (Use &OI : Curr->operands()) {
       if (Instruction *Inst = dyn_cast<Instruction>(OI))
         if (Alive.insert(Inst).second)
@@ -61,10 +95,30 @@ static bool aggressiveDCE(Function& F) {
   // value of the function, and may therefore be deleted safely.
   // NOTE: We reuse the Worklist vector here for memory efficiency.
   for (Instruction &I : instructions(F)) {
-    if (!Alive.count(&I)) {
-      Worklist.push_back(&I);
-      I.dropAllReferences();
+    // Check if the instruction is alive.
+    if (Alive.count(&I))
+      continue;
+
+    if (auto *DII = dyn_cast<DbgInfoIntrinsic>(&I)) {
+      // Check if the scope of this variable location is alive.
+      if (AliveScopes.count(DII->getDebugLoc()->getScope()))
+        continue;
+
+      // Fallthrough and drop the intrinsic.
+      DEBUG({
+        // If intrinsic is pointing at a live SSA value, there may be an
+        // earlier optimization bug: if we know the location of the variable,
+        // why isn't the scope of the location alive?
+        if (Value *V = DII->getVariableLocation())
+          if (Instruction *II = dyn_cast<Instruction>(V))
+            if (Alive.count(II))
+              dbgs() << "Dropping debug info for " << *DII << "\n";
+      });
     }
+
+    // Prepare to delete.
+    Worklist.push_back(&I);
+    I.dropAllReferences();
   }
 
   for (Instruction *&I : Worklist) {
diff --git a/llvm/test/Assembler/2010-02-05-FunctionLocalMetadataBecomesNull.ll b/llvm/test/Assembler/2010-02-05-FunctionLocalMetadataBecomesNull.ll
index 0a2462610acb..a049f18fd594 100644
--- a/llvm/test/Assembler/2010-02-05-FunctionLocalMetadataBecomesNull.ll
+++ b/llvm/test/Assembler/2010-02-05-FunctionLocalMetadataBecomesNull.ll
@@ -19,7 +19,7 @@ define i32 @main() nounwind readonly !dbg !1 {
   %v2 = ptrtoint %struct.test* %v1 to i64 ; <i64> [#uses=1]
   %v3 = sub i64 %v2, ptrtoint ([10 x %struct.test]* @TestArray to i64) ; <i64> [#uses=1]
   store i64 %v3, i64* %diff1, align 8
-  ret i32 4
+  ret i32 4, !dbg !DILocation(scope: !1)
 }
 
 declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
diff --git a/llvm/test/Transforms/ADCE/debug-info-intrinsic.ll b/llvm/test/Transforms/ADCE/debug-info-intrinsic.ll
new file mode 100644
index 000000000000..fc8011bd87a1
--- /dev/null
+++ b/llvm/test/Transforms/ADCE/debug-info-intrinsic.ll
@@ -0,0 +1,101 @@
+; RUN: opt -adce -S < %s | FileCheck %s
+; Test that debug info intrinsics in dead scopes get eliminated by -adce.
+
+; Generated with 'clang -g -S -emit-llvm | opt -mem2reg -inline' at r262899
+; (before -adce was augmented) and then hand-reduced.  This was the input:
+;
+;;void sink(void);
+;;
+;;void variable_in_unused_subscope(void) {
+;;  { int i = 0; }
+;;  sink();
+;;}
+;;
+;;void variable_in_parent_scope(void) {
+;;  int i = 0;
+;;  { sink(); }
+;;}
+;;
+;;static int empty_function_with_unused_variable(void) {
+;;  { int i = 0; }
+;;  return 0;
+;;}
+;;
+;;void calls_empty_function_with_unused_variable_in_unused_subscope(void) {
+;;  { empty_function_with_unused_variable(); }
+;;  sink();
+;;}
+
+declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
+
+declare void @sink()
+
+; CHECK-LABEL: define void @variable_in_unused_subscope(
+define void @variable_in_unused_subscope() !dbg !4 {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   call void @sink
+; CHECK-NEXT:   ret void
+entry:
+  call void @llvm.dbg.value(metadata i32 0, i64 0, metadata !15, metadata !17), !dbg !18
+  call void @sink(), !dbg !19
+  ret void, !dbg !20
+}
+
+; CHECK-LABEL: define void @variable_in_parent_scope(
+define void @variable_in_parent_scope() !dbg !7 {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   call void @llvm.dbg.value
+; CHECK-NEXT:   call void @sink
+; CHECK-NEXT:   ret void
+entry:
+  call void @llvm.dbg.value(metadata i32 0, i64 0, metadata !21, metadata !17), !dbg !22
+  call void @sink(), !dbg !23
+  ret void, !dbg !25
+}
+
+; CHECK-LABEL: define void @calls_empty_function_with_unused_variable_in_unused_subscope(
+define void @calls_empty_function_with_unused_variable_in_unused_subscope() !dbg !8 {
+; CHECK-NEXT: entry:
+; CHECK-NEXT:   call void @sink
+; CHECK-NEXT:   ret void
+entry:
+  call void @llvm.dbg.value(metadata i32 0, i64 0, metadata !26, metadata !17), !dbg !28
+  call void @sink(), !dbg !31
+  ret void, !dbg !32
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!14}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3)
+!1 = !DIFile(filename: "t.c", directory: "/path/to/test/Transforms/ADCE")
+!2 = !{}
+!3 = !{!4, !7, !8, !10}
+!4 = distinct !DISubprogram(name: "variable_in_unused_subscope", scope: !1, file: !1, line: 3, type: !5, isLocal: false, isDefinition: true, scopeLine: 3, flags: DIFlagPrototyped, isOptimized: false, variables: !2)
+!5 = !DISubroutineType(types: !6)
+!6 = !{null}
+!7 = distinct !DISubprogram(name: "variable_in_parent_scope", scope: !1, file: !1, line: 8, type: !5, isLocal: false, isDefinition: true, scopeLine: 8, flags: DIFlagPrototyped, isOptimized: false, variables: !2)
+!8 = distinct !DISubprogram(name: "calls_empty_function_with_unused_variable_in_unused_subscope", scope: !1, file: !1, line: 18, type: !5, isLocal: false, isDefinition: true, scopeLine: 18, flags: DIFlagPrototyped, isOptimized: false, variables: !2)
+!10 = distinct !DISubprogram(name: "empty_function_with_unused_variable", scope: !1, file: !1, line: 13, type: !11, isLocal: true, isDefinition: true, scopeLine: 13, flags: DIFlagPrototyped, isOptimized: false, variables: !2)
+!11 = !DISubroutineType(types: !12)
+!12 = !{!13}
+!13 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+!14 = !{i32 2, !"Debug Info Version", i32 3}
+!15 = !DILocalVariable(name: "i", scope: !16, file: !1, line: 4, type: !13)
+!16 = distinct !DILexicalBlock(scope: !4, file: !1, line: 4, column: 3)
+!17 = !DIExpression()
+!18 = !DILocation(line: 4, column: 9, scope: !16)
+!19 = !DILocation(line: 5, column: 3, scope: !4)
+!20 = !DILocation(line: 6, column: 1, scope: !4)
+!21 = !DILocalVariable(name: "i", scope: !7, file: !1, line: 9, type: !13)
+!22 = !DILocation(line: 9, column: 7, scope: !7)
+!23 = !DILocation(line: 10, column: 5, scope: !24)
+!24 = distinct !DILexicalBlock(scope: !7, file: !1, line: 10, column: 3)
+!25 = !DILocation(line: 11, column: 1, scope: !7)
+!26 = !DILocalVariable(name: "i", scope: !27, file: !1, line: 14, type: !13)
+!27 = distinct !DILexicalBlock(scope: !10, file: !1, line: 14, column: 3)
+!28 = !DILocation(line: 14, column: 9, scope: !27, inlinedAt: !29)
+!29 = distinct !DILocation(line: 19, column: 5, scope: !30)
+!30 = distinct !DILexicalBlock(scope: !8, file: !1, line: 19, column: 3)
+!31 = !DILocation(line: 20, column: 3, scope: !8)
+!32 = !DILocation(line: 21, column: 1, scope: !8)