Index: cfe/trunk/lib/CodeGen/CGDebugInfo.h
===================================================================
--- cfe/trunk/lib/CodeGen/CGDebugInfo.h
+++ cfe/trunk/lib/CodeGen/CGDebugInfo.h
@@ -293,6 +293,15 @@
   /// Create a new lexical block node and push it on the stack.
   void CreateLexicalBlock(SourceLocation Loc);
 
+  /// If target-specific LLVM \p AddressSpace directly maps to target-specific
+  /// DWARF address space, appends extended dereferencing mechanism to complex
+  /// expression \p Expr. Otherwise, does nothing.
+  ///
+  /// Extended dereferencing mechanism is has the following format:
+  ///     DW_OP_constu <DWARF Address Space> DW_OP_swap DW_OP_xderef
+  void AppendAddressSpaceXDeref(unsigned AddressSpace,
+                                SmallVectorImpl<int64_t> &Expr) const;
+
 public:
   CGDebugInfo(CodeGenModule &CGM);
   ~CGDebugInfo();
Index: cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
===================================================================
--- cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
+++ cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
@@ -3272,6 +3272,20 @@
       getColumnNumber(CurLoc)));
 }
 
+void CGDebugInfo::AppendAddressSpaceXDeref(
+    unsigned AddressSpace,
+    SmallVectorImpl<int64_t> &Expr) const {
+  Optional<unsigned> DWARFAddressSpace =
+      CGM.getTarget().getDWARFAddressSpace(AddressSpace);
+  if (!DWARFAddressSpace)
+    return;
+
+  Expr.push_back(llvm::dwarf::DW_OP_constu);
+  Expr.push_back(DWARFAddressSpace.getValue());
+  Expr.push_back(llvm::dwarf::DW_OP_swap);
+  Expr.push_back(llvm::dwarf::DW_OP_xderef);
+}
+
 void CGDebugInfo::EmitLexicalBlockStart(CGBuilderTy &Builder,
                                         SourceLocation Loc) {
   // Set our current location.
@@ -3422,13 +3436,16 @@
     Line = getLineNumber(VD->getLocation());
     Column = getColumnNumber(VD->getLocation());
   }
-  SmallVector<int64_t, 9> Expr;
+  SmallVector<int64_t, 13> Expr;
   llvm::DINode::DIFlags Flags = llvm::DINode::FlagZero;
   if (VD->isImplicit())
     Flags |= llvm::DINode::FlagArtificial;
 
   auto Align = getDeclAlignIfRequired(VD, CGM.getContext());
 
+  unsigned AddressSpace = CGM.getContext().getTargetAddressSpace(VD->getType());
+  AppendAddressSpaceXDeref(AddressSpace, Expr);
+
   // If this is the first argument and it is implicit then
   // give it an object pointer flag.
   // FIXME: There has to be a better way to do this, but for static
@@ -3857,9 +3874,16 @@
     GVE = CollectAnonRecordDecls(RD, Unit, LineNo, LinkageName, Var, DContext);
   } else {
     auto Align = getDeclAlignIfRequired(D, CGM.getContext());
+
+    SmallVector<int64_t, 4> Expr;
+    unsigned AddressSpace =
+        CGM.getContext().getTargetAddressSpace(D->getType());
+    AppendAddressSpaceXDeref(AddressSpace, Expr);
+
     GVE = DBuilder.createGlobalVariableExpression(
         DContext, DeclName, LinkageName, Unit, LineNo, getOrCreateType(T, Unit),
-        Var->hasLocalLinkage(), /*Expr=*/nullptr,
+        Var->hasLocalLinkage(),
+        Expr.empty() ? nullptr : DBuilder.createExpression(Expr),
         getOrCreateStaticDataMemberDeclarationOrNull(D), Align);
     Var->addDebugInfo(GVE);
   }
Index: cfe/trunk/test/CodeGenOpenCL/amdgpu-debug-info-variable-expression.cl
===================================================================
--- cfe/trunk/test/CodeGenOpenCL/amdgpu-debug-info-variable-expression.cl
+++ cfe/trunk/test/CodeGenOpenCL/amdgpu-debug-info-variable-expression.cl
@@ -0,0 +1,131 @@
+// RUN: %clang -cl-std=CL2.0 -emit-llvm -g -O0 -S -target amdgcn-amd-amdhsa -mcpu=fiji -o - %s | FileCheck %s
+
+// CHECK-DAG: ![[NONE:[0-9]+]] = !DIExpression()
+// CHECK-DAG: ![[LOCAL:[0-9]+]] = !DIExpression(DW_OP_constu, 2, DW_OP_swap, DW_OP_xderef)
+// CHECK-DAG: ![[PRIVATE:[0-9]+]] = !DIExpression(DW_OP_constu, 1, DW_OP_swap, DW_OP_xderef)
+
+// CHECK-DAG: ![[FILEVAR0:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar0", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR0]])
+global int *FileVar0;
+// CHECK-DAG: ![[FILEVAR1:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar1", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR1]])
+constant int *FileVar1;
+// CHECK-DAG: ![[FILEVAR2:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar2", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR2]])
+local int *FileVar2;
+// CHECK-DAG: ![[FILEVAR3:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar3", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR3]])
+private int *FileVar3;
+// CHECK-DAG: ![[FILEVAR4:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar4", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR4]])
+int *FileVar4;
+
+// CHECK-DAG: ![[FILEVAR5:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar5", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR5]])
+global int *global FileVar5;
+// CHECK-DAG: ![[FILEVAR6:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar6", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR6]])
+constant int *global FileVar6;
+// CHECK-DAG: ![[FILEVAR7:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar7", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR7]])
+local int *global FileVar7;
+// CHECK-DAG: ![[FILEVAR8:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar8", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR8]])
+private int *global FileVar8;
+// CHECK-DAG: ![[FILEVAR9:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar9", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR9]])
+int *global FileVar9;
+
+// CHECK-DAG: ![[FILEVAR10:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar10", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR10]])
+global int *constant FileVar10 = 0;
+// CHECK-DAG: ![[FILEVAR11:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar11", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR11]])
+constant int *constant FileVar11 = 0;
+// CHECK-DAG: ![[FILEVAR12:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar12", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR12]])
+local int *constant FileVar12 = 0;
+// CHECK-DAG: ![[FILEVAR13:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar13", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR13]])
+private int *constant FileVar13 = 0;
+// CHECK-DAG: ![[FILEVAR14:[0-9]+]] = distinct !DIGlobalVariable(name: "FileVar14", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: false, isDefinition: true)
+// CHECK-DAG: !DIGlobalVariableExpression(var: ![[FILEVAR14]])
+int *constant FileVar14 = 0;
+
+kernel void kernel1(
+    // CHECK-DAG: ![[KERNELARG0:[0-9]+]] = !DILocalVariable(name: "KernelArg0", arg: {{[0-9]+}}, scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+    // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(1)** {{.*}}, metadata ![[KERNELARG0]], metadata ![[PRIVATE]]), !dbg !{{[0-9]+}}
+    global int *KernelArg0,
+    // CHECK-DAG: ![[KERNELARG1:[0-9]+]] = !DILocalVariable(name: "KernelArg1", arg: {{[0-9]+}}, scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+    // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(2)** {{.*}}, metadata ![[KERNELARG1]], metadata ![[PRIVATE]]), !dbg !{{[0-9]+}}
+    constant int *KernelArg1,
+    // CHECK-DAG: ![[KERNELARG2:[0-9]+]] = !DILocalVariable(name: "KernelArg2", arg: {{[0-9]+}}, scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+    // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(3)** {{.*}}, metadata ![[KERNELARG2]], metadata ![[PRIVATE]]), !dbg !{{[0-9]+}}
+    local int *KernelArg2) {
+  private int *Tmp0;
+  int *Tmp1;
+
+  // CHECK-DAG: ![[FUNCVAR0:[0-9]+]] = !DILocalVariable(name: "FuncVar0", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(1)** {{.*}}, metadata ![[FUNCVAR0]], metadata ![[PRIVATE]]), !dbg !{{[0-9]+}}
+  global int *FuncVar0 = KernelArg0;
+  // CHECK-DAG: ![[FUNCVAR1:[0-9]+]] = !DILocalVariable(name: "FuncVar1", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(2)** {{.*}}, metadata ![[FUNCVAR1]], metadata ![[PRIVATE]]), !dbg !{{[0-9]+}}
+  constant int *FuncVar1 = KernelArg1;
+  // CHECK-DAG: ![[FUNCVAR2:[0-9]+]] = !DILocalVariable(name: "FuncVar2", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(3)** {{.*}}, metadata ![[FUNCVAR2]], metadata ![[PRIVATE]]), !dbg !{{[0-9]+}}
+  local int *FuncVar2 = KernelArg2;
+  // CHECK-DAG: ![[FUNCVAR3:[0-9]+]] = !DILocalVariable(name: "FuncVar3", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32** {{.*}}, metadata ![[FUNCVAR3]], metadata ![[PRIVATE]]), !dbg !{{[0-9]+}}
+  private int *FuncVar3 = Tmp0;
+  // CHECK-DAG: ![[FUNCVAR4:[0-9]+]] = !DILocalVariable(name: "FuncVar4", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(4)** {{.*}}, metadata ![[FUNCVAR4]], metadata ![[PRIVATE]]), !dbg !{{[0-9]+}}
+  int *FuncVar4 = Tmp1;
+
+  // CHECK-DAG: ![[FUNCVAR5:[0-9]+]] = !DILocalVariable(name: "FuncVar5", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(1)** {{.*}}, metadata ![[FUNCVAR5]], metadata ![[NONE]]), !dbg !{{[0-9]+}}
+  global int *constant FuncVar5 = KernelArg0;
+  // CHECK-DAG: ![[FUNCVAR6:[0-9]+]] = !DILocalVariable(name: "FuncVar6", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(2)** {{.*}}, metadata ![[FUNCVAR6]], metadata ![[NONE]]), !dbg !{{[0-9]+}}
+  constant int *constant FuncVar6 = KernelArg1;
+  // CHECK-DAG: ![[FUNCVAR7:[0-9]+]] = !DILocalVariable(name: "FuncVar7", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(3)** {{.*}}, metadata ![[FUNCVAR7]], metadata ![[NONE]]), !dbg !{{[0-9]+}}
+  local int *constant FuncVar7 = KernelArg2;
+  // CHECK-DAG: ![[FUNCVAR8:[0-9]+]] = !DILocalVariable(name: "FuncVar8", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32** {{.*}}, metadata ![[FUNCVAR8]], metadata ![[NONE]]), !dbg !{{[0-9]+}}
+  private int *constant FuncVar8 = Tmp0;
+  // CHECK-DAG: ![[FUNCVAR9:[0-9]+]] = !DILocalVariable(name: "FuncVar9", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(4)** {{.*}}, metadata ![[FUNCVAR9]], metadata ![[NONE]]), !dbg !{{[0-9]+}}
+  int *constant FuncVar9 = Tmp1;
+
+  // CHECK-DAG: ![[FUNCVAR10:[0-9]+]] = distinct !DIGlobalVariable(name: "FuncVar10", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: true, isDefinition: true)
+  // CHECK-DAG: !DIGlobalVariableExpression(var: ![[FUNCVAR10]], expr: ![[LOCAL]])
+  global int *local FuncVar10; FuncVar10 = KernelArg0;
+  // CHECK-DAG: ![[FUNCVAR11:[0-9]+]] = distinct !DIGlobalVariable(name: "FuncVar11", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: true, isDefinition: true)
+  // CHECK-DAG: !DIGlobalVariableExpression(var: ![[FUNCVAR11]], expr: ![[LOCAL]])
+  constant int *local FuncVar11; FuncVar11 = KernelArg1;
+  // CHECK-DAG: ![[FUNCVAR12:[0-9]+]] = distinct !DIGlobalVariable(name: "FuncVar12", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: true, isDefinition: true)
+  // CHECK-DAG: !DIGlobalVariableExpression(var: ![[FUNCVAR12]], expr: ![[LOCAL]])
+  local int *local FuncVar12; FuncVar12 = KernelArg2;
+  // CHECK-DAG: ![[FUNCVAR13:[0-9]+]] = distinct !DIGlobalVariable(name: "FuncVar13", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: true, isDefinition: true)
+  // CHECK-DAG: !DIGlobalVariableExpression(var: ![[FUNCVAR13]], expr: ![[LOCAL]])
+  private int *local FuncVar13; FuncVar13 = Tmp0;
+  // CHECK-DAG: ![[FUNCVAR14:[0-9]+]] = distinct !DIGlobalVariable(name: "FuncVar14", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}}, isLocal: true, isDefinition: true)
+  // CHECK-DAG: !DIGlobalVariableExpression(var: ![[FUNCVAR14]], expr: ![[LOCAL]])
+  int *local FuncVar14; FuncVar14 = Tmp1;
+
+  // CHECK-DAG: ![[FUNCVAR15:[0-9]+]] = !DILocalVariable(name: "FuncVar15", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(1)** {{.*}}, metadata ![[FUNCVAR15]], metadata ![[PRIVATE]]), !dbg !{{[0-9]+}}
+  global int *private FuncVar15 = KernelArg0;
+  // CHECK-DAG: ![[FUNCVAR16:[0-9]+]] = !DILocalVariable(name: "FuncVar16", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(2)** {{.*}}, metadata ![[FUNCVAR16]], metadata ![[PRIVATE]]), !dbg !{{[0-9]+}}
+  constant int *private FuncVar16 = KernelArg1;
+  // CHECK-DAG: ![[FUNCVAR17:[0-9]+]] = !DILocalVariable(name: "FuncVar17", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(3)** {{.*}}, metadata ![[FUNCVAR17]], metadata ![[PRIVATE]]), !dbg !{{[0-9]+}}
+  local int *private FuncVar17 = KernelArg2;
+  // CHECK-DAG: ![[FUNCVAR18:[0-9]+]] = !DILocalVariable(name: "FuncVar18", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32** {{.*}}, metadata ![[FUNCVAR18]], metadata ![[PRIVATE]]), !dbg !{{[0-9]+}}
+  private int *private FuncVar18 = Tmp0;
+  // CHECK-DAG: ![[FUNCVAR19:[0-9]+]] = !DILocalVariable(name: "FuncVar19", scope: !{{[0-9]+}}, file: !{{[0-9]+}}, line: {{[0-9]+}}, type: !{{[0-9]+}})
+  // CHECK-DAG: call void @llvm.dbg.declare(metadata i32 addrspace(4)** {{.*}}, metadata ![[FUNCVAR19]], metadata ![[PRIVATE]]), !dbg !{{[0-9]+}}
+  int *private FuncVar19 = Tmp1;
+}