Index: lib/CodeGen/CodeGenPrepare.cpp
===================================================================
--- lib/CodeGen/CodeGenPrepare.cpp
+++ lib/CodeGen/CodeGenPrepare.cpp
@@ -4929,6 +4929,19 @@
   // value, this should be idempotent.
   SunkAddrs[Addr] = WeakTrackingVH(SunkAddr);
 
+  // Redirect debug intrinsic users in the local block to the locally computed
+  // address.
+  SmallVector<DbgVariableIntrinsic *, 4> DbgUsers;
+  findDbgUsers(DbgUsers, Repl);
+  for (auto &User : DbgUsers) {
+    // Discard debug users in other blocks.
+    if (User->getParent() != MemoryInst->getParent())
+      continue;
+
+    User->setOperand(0, MetadataAsValue::get(User->getContext(),
+                                             ValueAsMetadata::get(SunkAddr)));
+  };
+
   // If we have no uses, recursively delete the value and all dead instructions
   // using it.
   if (Repl->use_empty()) {
Index: test/DebugInfo/Generic/codegenprep-addrsink.ll
===================================================================
--- /dev/null
+++ test/DebugInfo/Generic/codegenprep-addrsink.ll
@@ -0,0 +1,53 @@
+; RUN: llc -start-before=codegenprepare -stop-after=codegenprepare %s -o - | FileCheck %s
+;
+; CGP duplicates address calculation into each basic block that contains loads
+; or stores, so that they can be folded into instruction memory operands for
+; example. dbg.value's should be redirected to identify such local address
+; computations, to give the best opportunity for variable locations to be
+; preserved.
+
+define dso_local i8 @foo(i32 *%p, i32 %cond) !dbg !7 {
+entry:
+  %casted = bitcast i32 *%p to i8*
+  %arith = getelementptr i8, i8 *%casted, i32 3
+  %cmpresult = icmp eq i32 %cond, 0
+  br i1 %cmpresult, label %next, label %ret
+
+next:
+; Address calcs should be duplicated into this block, and the dbg.value
+; should refer to the address calculated _in_ the block.
+; CHECK-LABEL: next:
+; CHECK:       %[[CASTVAR:[0-9a-zA-Z]+]] = bitcast i32* %p to i8*
+; CHECK-NEXT:  %[[GEPVAR:[0-9a-zA-Z]+]] = getelementptr i8, i8* %[[CASTVAR]], i64 3
+; CHECK-NEXT:  call void @llvm.dbg.value(metadata i8* %[[GEPVAR]], metadata ![[DIVAR:[0-9]+]],
+  call void @llvm.dbg.value(metadata i8 *%arith, metadata !12, metadata !DIExpression()), !dbg !14
+  %loaded = load i8, i8 *%arith
+  ret i8 %loaded
+
+ret:
+  ret i8 0
+}
+
+; CHECK: ![[DIVAR]] = !DILocalVariable(name: "p",
+
+declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "test.cpp", directory: ".")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 8.0.0 (trunk 348209)"}
+!7 = distinct !DISubprogram(name: "foo", linkageName: "foo", scope: !1, file: !1, line: 4, type: !8, scopeLine: 5, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !11)
+!8 = !DISubroutineType(types: !9)
+!9 = !{null, !10}
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !{!12}
+!12 = !DILocalVariable(name: "p", arg: 1, scope: !7, file: !1, line: 4, type: !10)
+!14 = !DILocation(line: 4, column: 15, scope: !7)
+!20 = distinct !DILexicalBlock(scope: !7, file: !1, line: 8, column: 7)