Index: docs/LangRef.rst
===================================================================
--- docs/LangRef.rst
+++ docs/LangRef.rst
@@ -4405,6 +4405,7 @@
 
 - ``DW_OP_deref`` dereferences the top of the expression stack.
 - ``DW_OP_plus, 93`` adds ``93`` to the working expression.
+- ``DW_OP_plus_uconst, 93`` adds ``93`` to the working expression.
 - ``DW_OP_LLVM_fragment, 16, 8`` specifies the offset and size (``16`` and ``8``
   here, respectively) of the variable fragment from the working expression. Note
   that contrary to DW_OP_bit_piece, the offset is describing the the location
@@ -4427,6 +4428,7 @@
 
     !0 = !DIExpression(DW_OP_deref)
     !1 = !DIExpression(DW_OP_plus, 3)
+    !1 = !DIExpression(DW_OP_plus_uconst, 3)
     !2 = !DIExpression(DW_OP_bit_piece, 3, 7)
     !3 = !DIExpression(DW_OP_deref, DW_OP_plus, 3, DW_OP_LLVM_fragment, 3, 7)
     !4 = !DIExpression(DW_OP_constu, 2, DW_OP_swap, DW_OP_xderef)
Index: lib/CodeGen/AsmPrinter/DwarfExpression.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/DwarfExpression.cpp
+++ lib/CodeGen/AsmPrinter/DwarfExpression.cpp
@@ -248,6 +248,12 @@
   assert(Reg.Size == 0 && "subregister has same size as superregister");
 
   // Pattern-match combinations for which more efficient representations exist.
+  // [Reg, DW_OP_plus_uconst, Offset] --> [DW_OP_breg, Offset].
+  if (Op && (Op->getOp() == dwarf::DW_OP_plus_uconst)) {
+    SignedOffset = Op->getArg(0);
+    ExprCursor.take();
+  }
+
   // [Reg, Offset, DW_OP_plus] --> [DW_OP_breg, Offset].
   // [Reg, Offset, DW_OP_minus] --> [DW_OP_breg, -Offset].
   // If Reg is a subregister we need to mask it out before subtracting.
@@ -321,6 +327,7 @@
       return;
     }
     case dwarf::DW_OP_plus:
+    case dwarf::DW_OP_plus_uconst:
       assert(LocationKind != Register);
       emitOp(dwarf::DW_OP_plus_uconst);
       emitUnsigned(Op->getArg(0));
Index: lib/IR/DebugInfoMetadata.cpp
===================================================================
--- lib/IR/DebugInfoMetadata.cpp
+++ lib/IR/DebugInfoMetadata.cpp
@@ -599,6 +599,7 @@
     return 3;
   case dwarf::DW_OP_constu:
   case dwarf::DW_OP_plus:
+  case dwarf::DW_OP_plus_uconst:
   case dwarf::DW_OP_minus:
     return 2;
   default:
@@ -641,6 +642,7 @@
       break;
     }
     case dwarf::DW_OP_constu:
+    case dwarf::DW_OP_plus_uconst:
     case dwarf::DW_OP_plus:
     case dwarf::DW_OP_minus:
     case dwarf::DW_OP_deref:
@@ -679,7 +681,8 @@
   }
   if (getNumElements() != 2)
     return false;
-  if (Elements[0] == dwarf::DW_OP_plus) {
+  if (Elements[0] == dwarf::DW_OP_plus ||
+      Elements[0] == dwarf::DW_OP_plus_uconst) {
     Offset = Elements[1];
     return true;
   }
Index: test/Assembler/diexpression.ll
===================================================================
--- test/Assembler/diexpression.ll
+++ test/Assembler/diexpression.ll
@@ -1,8 +1,8 @@
 ; RUN: llvm-as < %s | llvm-dis | llvm-as | llvm-dis | FileCheck %s
 ; RUN: verify-uselistorder %s
 
-; CHECK: !named = !{!0, !1, !2, !3, !4, !5}
-!named = !{!0, !1, !2, !3, !4, !5}
+; CHECK: !named = !{!0, !1, !2, !3, !4, !5, !6}
+!named = !{!0, !1, !2, !3, !4, !5, !6}
 
 ; CHECK:      !0 = !DIExpression()
 ; CHECK-NEXT: !1 = !DIExpression(DW_OP_deref)
@@ -10,9 +10,11 @@
 ; CHECK-NEXT: !3 = !DIExpression(DW_OP_LLVM_fragment, 3, 7)
 ; CHECK-NEXT: !4 = !DIExpression(DW_OP_deref, DW_OP_plus, 3, DW_OP_LLVM_fragment, 3, 7)
 ; CHECK-NEXT: !5 = !DIExpression(DW_OP_constu, 2, DW_OP_swap, DW_OP_xderef)
+; CHECK-NEXT: !6 = !DIExpression(DW_OP_plus_uconst, 3)
 !0 = !DIExpression()
 !1 = !DIExpression(DW_OP_deref)
 !2 = !DIExpression(DW_OP_plus, 3)
 !3 = !DIExpression(DW_OP_LLVM_fragment, 3, 7)
 !4 = !DIExpression(DW_OP_deref, DW_OP_plus, 3, DW_OP_LLVM_fragment, 3, 7)
 !5 = !DIExpression(DW_OP_constu, 2, DW_OP_swap, DW_OP_xderef)
+!6 = !DIExpression(DW_OP_plus_uconst, 3)
Index: unittests/IR/MetadataTest.cpp
===================================================================
--- unittests/IR/MetadataTest.cpp
+++ unittests/IR/MetadataTest.cpp
@@ -2043,6 +2043,7 @@
 
   // Valid constructions.
   EXPECT_VALID(dwarf::DW_OP_plus, 6);
+  EXPECT_VALID(dwarf::DW_OP_plus_uconst, 6);
   EXPECT_VALID(dwarf::DW_OP_deref);
   EXPECT_VALID(dwarf::DW_OP_LLVM_fragment, 3, 7);
   EXPECT_VALID(dwarf::DW_OP_plus, 6, dwarf::DW_OP_deref);
@@ -2054,6 +2055,7 @@
   // Invalid constructions.
   EXPECT_INVALID(~0u);
   EXPECT_INVALID(dwarf::DW_OP_plus);
+  EXPECT_INVALID(dwarf::DW_OP_plus_uconst);
   EXPECT_INVALID(dwarf::DW_OP_LLVM_fragment);
   EXPECT_INVALID(dwarf::DW_OP_LLVM_fragment, 3);
   EXPECT_INVALID(dwarf::DW_OP_LLVM_fragment, 3, 7, dwarf::DW_OP_plus, 3);