From: Florian Hahn <florian.hahn@arm.com>
Date: Wed, 14 Jun 2017 13:14:38 +0000 (+0000)
Subject: Align definition of DW_OP_plus with DWARF spec [3/3]
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=50963b3b75627a63ddceb22ef2b80b5c16c0a028;p=llvm

Align definition of DW_OP_plus with DWARF spec [3/3]

Summary:
This patch is part of 3 patches that together form a single patch, but must be introduced in stages in order not to break things.

The way that LLVM interprets DW_OP_plus in DIExpression nodes is basically that of the DW_OP_plus_uconst operator since LLVM expects an unsigned constant operand. This unnecessarily restricts the DW_OP_plus operator, preventing it from being used to describe the evaluation of runtime values on the expression stack. These patches try to align the semantics of DW_OP_plus and DW_OP_minus with that of the DWARF definition, which pops two elements off the expression stack, performs the operation and pushes the result back on the stack.

This is done in three stages:
• The first patch (LLVM) adds support for DW_OP_plus_uconst.
• The second patch (Clang) contains changes all its uses from DW_OP_plus to DW_OP_plus_uconst.
• The third patch (LLVM) changes the semantics of DW_OP_plus and DW_OP_minus to be in line with its DWARF meaning. This patch includes the bitcode upgrade from legacy DIExpressions.

Patch by Sander de Smalen.

Reviewers: echristo, pcc, aprantl

Reviewed By: aprantl

Subscribers: fhahn, javed.absar, aprantl, llvm-commits

Differential Revision: https://reviews.llvm.org/D33894

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@305386 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/docs/LangRef.rst b/docs/LangRef.rst
index 24362825d82..ec445489d8b 100644
--- a/docs/LangRef.rst
+++ b/docs/LangRef.rst
@@ -4404,7 +4404,11 @@ referenced LLVM variable relates to the source language variable.
 The current supported vocabulary is limited:
 
 - ``DW_OP_deref`` dereferences the top of the expression stack.
-- ``DW_OP_plus, 93`` adds ``93`` to the working expression.
+- ``DW_OP_plus`` pops the last two entries from the expression stack, adds
+  them together and appends the result to the expression stack.
+- ``DW_OP_minus`` pops the last two entries from the expression stack, subtracts
+  the last entry from the second last entry and appends the result to the
+  expression stack.
 - ``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
@@ -4427,10 +4431,10 @@ combined with a concrete location.
 .. code-block:: llvm
 
     !0 = !DIExpression(DW_OP_deref)
-    !1 = !DIExpression(DW_OP_plus, 3)
     !1 = !DIExpression(DW_OP_plus_uconst, 3)
+    !1 = !DIExpression(DW_OP_constu, 3, DW_OP_plus)
     !2 = !DIExpression(DW_OP_bit_piece, 3, 7)
-    !3 = !DIExpression(DW_OP_deref, DW_OP_plus, 3, DW_OP_LLVM_fragment, 3, 7)
+    !3 = !DIExpression(DW_OP_deref, DW_OP_constu, 3, DW_OP_plus, DW_OP_LLVM_fragment, 3, 7)
     !4 = !DIExpression(DW_OP_constu, 2, DW_OP_swap, DW_OP_xderef)
     !5 = !DIExpression(DW_OP_constu, 42, DW_OP_stack_value)
 
diff --git a/include/llvm/IR/DebugInfoMetadata.h b/include/llvm/IR/DebugInfoMetadata.h
index 2174e1f301e..9374fe4fae7 100644
--- a/include/llvm/IR/DebugInfoMetadata.h
+++ b/include/llvm/IR/DebugInfoMetadata.h
@@ -2117,9 +2117,6 @@ public:
 /// variable, or the location of a single piece of a variable, or (when using
 /// DW_OP_stack_value) is the constant variable value.
 ///
-/// FIXME: Instead of DW_OP_plus taking an argument, this should use DW_OP_const
-/// and have DW_OP_plus consume the topmost elements on the stack.
-///
 /// TODO: Co-allocate the expression elements.
 /// TODO: Separate from MDNode, or otherwise drop Distinct and Temporary
 /// storage types.
diff --git a/lib/Bitcode/Reader/MetadataLoader.cpp b/lib/Bitcode/Reader/MetadataLoader.cpp
index ee2fe2a0cc1..b1504a8034e 100644
--- a/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -407,6 +407,11 @@ void PlaceholderQueue::flush(BitcodeReaderMetadataList &MetadataList) {
 
 } // anonynous namespace
 
+static Error error(const Twine &Message) {
+  return make_error<StringError>(
+      Message, make_error_code(BitcodeError::CorruptedBitcode));
+}
+
 class MetadataLoader::MetadataLoaderImpl {
   BitcodeReaderMetadataList MetadataList;
   BitcodeReaderValueList &ValueList;
@@ -533,6 +538,88 @@ class MetadataLoader::MetadataLoaderImpl {
             }
   }
 
+  /// Upgrade the expression from previous versions.
+  Error upgradeDIExpression(uint64_t FromVersion,
+                            MutableArrayRef<uint64_t> &Expr,
+                            SmallVectorImpl<uint64_t> &Buffer) {
+    auto N = Expr.size();
+    switch (FromVersion) {
+    default:
+      return error("Invalid record");
+    case 0:
+      if (N >= 3 && Expr[N - 3] == dwarf::DW_OP_bit_piece)
+        Expr[N - 3] = dwarf::DW_OP_LLVM_fragment;
+      LLVM_FALLTHROUGH;
+    case 1:
+      // Move DW_OP_deref to the end.
+      if (N && Expr[0] == dwarf::DW_OP_deref) {
+        auto End = Expr.end();
+        if (Expr.size() >= 3 &&
+            *std::prev(End, 3) == dwarf::DW_OP_LLVM_fragment)
+          End = std::prev(End, 3);
+        std::move(std::next(Expr.begin()), End, Expr.begin());
+        *std::prev(End) = dwarf::DW_OP_deref;
+      }
+      NeedDeclareExpressionUpgrade = true;
+      LLVM_FALLTHROUGH;
+    case 2: {
+      // Change DW_OP_plus to DW_OP_plus_uconst.
+      // Change DW_OP_minus to DW_OP_uconst, DW_OP_minus
+      auto SubExpr = ArrayRef<uint64_t>(Expr);
+      while (!SubExpr.empty()) {
+        // Skip past other operators with their operands
+        // for this version of the IR, obtained from
+        // from historic DIExpression::ExprOperand::getSize().
+        size_t HistoricSize;
+        switch (SubExpr.front()) {
+        default:
+          HistoricSize = 1;
+          break;
+        case dwarf::DW_OP_constu:
+        case dwarf::DW_OP_minus:
+        case dwarf::DW_OP_plus:
+          HistoricSize = 2;
+          break;
+        case dwarf::DW_OP_LLVM_fragment:
+          HistoricSize = 3;
+          break;
+        }
+
+        // If the expression is malformed, make sure we don't
+        // copy more elements than we should.
+        HistoricSize = std::min(SubExpr.size(), HistoricSize);
+        ArrayRef<uint64_t> Args = SubExpr.slice(1, HistoricSize-1);
+
+        switch (SubExpr.front()) {
+        case dwarf::DW_OP_plus:
+          Buffer.push_back(dwarf::DW_OP_plus_uconst);
+          Buffer.append(Args.begin(), Args.end());
+          break;
+        case dwarf::DW_OP_minus:
+          Buffer.push_back(dwarf::DW_OP_constu);
+          Buffer.append(Args.begin(), Args.end());
+          Buffer.push_back(dwarf::DW_OP_minus);
+          break;
+        default:
+          Buffer.push_back(*SubExpr.begin());
+          Buffer.append(Args.begin(), Args.end());
+          break;
+        }
+
+        // Continue with remaining elements.
+        SubExpr = SubExpr.slice(HistoricSize);
+      }
+      Expr = MutableArrayRef<uint64_t>(Buffer);
+      LLVM_FALLTHROUGH;
+    }
+    case 3:
+      // Up-to-date!
+      break;
+    }
+
+    return Error::success();
+  }
+
   void upgradeDebugInfo() {
     upgradeCUSubprograms();
     upgradeCUVariables();
@@ -590,11 +677,6 @@ public:
   void upgradeDebugIntrinsics(Function &F) { upgradeDeclareExpressions(F); }
 };
 
-static Error error(const Twine &Message) {
-  return make_error<StringError>(
-      Message, make_error_code(BitcodeError::CorruptedBitcode));
-}
-
 Expected<bool>
 MetadataLoader::MetadataLoaderImpl::lazyLoadModuleMetadataBlock() {
   IndexCursor = Stream;
@@ -1551,34 +1633,13 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     IsDistinct = Record[0] & 1;
     uint64_t Version = Record[0] >> 1;
     auto Elts = MutableArrayRef<uint64_t>(Record).slice(1);
-    unsigned N = Elts.size();
-    // Perform various upgrades.
-    switch (Version) {
-    case 0:
-      if (N >= 3 && Elts[N - 3] == dwarf::DW_OP_bit_piece)
-        Elts[N - 3] = dwarf::DW_OP_LLVM_fragment;
-      LLVM_FALLTHROUGH;
-    case 1:
-      // Move DW_OP_deref to the end.
-      if (N && Elts[0] == dwarf::DW_OP_deref) {
-        auto End = Elts.end();
-        if (Elts.size() >= 3 && *std::prev(End, 3) == dwarf::DW_OP_LLVM_fragment)
-          End = std::prev(End, 3);
-        std::move(std::next(Elts.begin()), End, Elts.begin());
-        *std::prev(End) = dwarf::DW_OP_deref;
-      }
-      NeedDeclareExpressionUpgrade = true;
-      LLVM_FALLTHROUGH;
-    case 2:
-      // Up-to-date!
-      break;
-    default:
-      return error("Invalid record");
-    }
+
+    SmallVector<uint64_t, 6> Buffer;
+    if (Error Err = upgradeDIExpression(Version, Elts, Buffer))
+      return Err;
 
     MetadataList.assignValue(
-        GET_OR_DISTINCT(DIExpression, (Context, makeArrayRef(Record).slice(1))),
-        NextMetadataNo);
+        GET_OR_DISTINCT(DIExpression, (Context, Elts)), NextMetadataNo);
     NextMetadataNo++;
     break;
   }
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index d5879fec95c..e679424bf1f 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1663,7 +1663,7 @@ void ModuleBitcodeWriter::writeDIExpression(const DIExpression *N,
                                             SmallVectorImpl<uint64_t> &Record,
                                             unsigned Abbrev) {
   Record.reserve(N->getElements().size() + 1);
-  const uint64_t Version = 2 << 1;
+  const uint64_t Version = 3 << 1;
   Record.push_back((uint64_t)N->isDistinct() | Version);
   Record.append(N->elements_begin(), N->elements_end());
 
diff --git a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
index 04073b3aed6..dc39d1e6cb5 100644
--- a/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -552,7 +552,7 @@ DIE *DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
     int Offset = TFI->getFrameIndexReference(*Asm->MF, Fragment.FI, FrameReg);
     DwarfExpr.addFragmentOffset(Expr);
     SmallVector<uint64_t, 8> Ops;
-    Ops.push_back(dwarf::DW_OP_plus);
+    Ops.push_back(dwarf::DW_OP_plus_uconst);
     Ops.push_back(Offset);
     Ops.append(Expr->elements_begin(), Expr->elements_end());
     DIExpressionCursor Cursor(Ops);
@@ -821,7 +821,7 @@ void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
 
   SmallVector<uint64_t, 8> Ops;
   if (Location.isIndirect() && Location.getOffset()) {
-    Ops.push_back(dwarf::DW_OP_plus);
+    Ops.push_back(dwarf::DW_OP_plus_uconst);
     Ops.push_back(Location.getOffset());
   }
   DIExpressionCursor Cursor(Ops);
@@ -850,7 +850,7 @@ void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
 
   SmallVector<uint64_t, 8> Ops;
   if (Location.isIndirect() && Location.getOffset()) {
-    Ops.push_back(dwarf::DW_OP_plus);
+    Ops.push_back(dwarf::DW_OP_plus_uconst);
     Ops.push_back(Location.getOffset());
   }
   Ops.append(DIExpr->elements_begin(), DIExpr->elements_end());
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index e3fd21a1fd7..75eb355bfb5 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1511,7 +1511,7 @@ static void emitDebugLocValue(const AsmPrinter &AP, const DIBasicType *BT,
       DwarfExpr.setMemoryLocationKind();
     SmallVector<uint64_t, 8> Ops;
     if (Location.isIndirect() && Location.getOffset()) {
-      Ops.push_back(dwarf::DW_OP_plus);
+      Ops.push_back(dwarf::DW_OP_plus_uconst);
       Ops.push_back(Location.getOffset());
     }
     Ops.append(DIExpr->elements_begin(), DIExpr->elements_end());
diff --git a/lib/CodeGen/AsmPrinter/DwarfExpression.cpp b/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
index 73ce58e3ca5..fe38ee80568 100644
--- a/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
@@ -254,15 +254,19 @@ bool DwarfExpression::addMachineRegExpression(const TargetRegisterInfo &TRI,
     ExprCursor.take();
   }
 
-  // [Reg, Offset, DW_OP_plus] --> [DW_OP_breg, Offset].
-  // [Reg, Offset, DW_OP_minus] --> [DW_OP_breg, -Offset].
+  // [Reg, DW_OP_constu, Offset, DW_OP_plus]  --> [DW_OP_breg, Offset]
+  // [Reg, DW_OP_constu, Offset, DW_OP_minus] --> [DW_OP_breg,-Offset]
   // If Reg is a subregister we need to mask it out before subtracting.
-  if (Op && ((Op->getOp() == dwarf::DW_OP_plus) ||
-             (Op->getOp() == dwarf::DW_OP_minus && !SubRegisterSizeInBits))) {
-    int Offset = Op->getArg(0);
-    SignedOffset = (Op->getOp() == dwarf::DW_OP_plus) ? Offset : -Offset;
-    ExprCursor.take();
+  if (Op && Op->getOp() == dwarf::DW_OP_constu) {
+    auto N = ExprCursor.peekNext();
+    if (N && (N->getOp() == dwarf::DW_OP_plus ||
+             (N->getOp() == dwarf::DW_OP_minus && !SubRegisterSizeInBits))) {
+      int Offset = Op->getArg(0);
+      SignedOffset = (N->getOp() == dwarf::DW_OP_minus) ? -Offset : Offset;
+      ExprCursor.consume(2);
+    }
   }
+
   if (FBReg)
     addFBReg(SignedOffset);
   else
@@ -326,18 +330,14 @@ void DwarfExpression::addExpression(DIExpressionCursor &&ExprCursor,
       LocationKind = Unknown;
       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));
       break;
+    case dwarf::DW_OP_plus:
     case dwarf::DW_OP_minus:
-      assert(LocationKind != Register);
-      // There is no DW_OP_minus_uconst.
-      emitOp(dwarf::DW_OP_constu);
-      emitUnsigned(Op->getArg(0));
-      emitOp(dwarf::DW_OP_minus);
+      emitOp(Op->getOp());
       break;
     case dwarf::DW_OP_deref: {
       assert(LocationKind != Register);
diff --git a/lib/CodeGen/AsmPrinter/DwarfExpression.h b/lib/CodeGen/AsmPrinter/DwarfExpression.h
index de861320006..728f8ad9225 100644
--- a/lib/CodeGen/AsmPrinter/DwarfExpression.h
+++ b/lib/CodeGen/AsmPrinter/DwarfExpression.h
@@ -42,6 +42,9 @@ public:
   DIExpressionCursor(ArrayRef<uint64_t> Expr)
       : Start(Expr.begin()), End(Expr.end()) {}
 
+  DIExpressionCursor(const DIExpressionCursor &C)
+      : Start(C.Start), End(C.End) {}
+
   /// Consume one operation.
   Optional<DIExpression::ExprOperand> take() {
     if (Start == End)
diff --git a/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 7f7d3e650e0..708f5f7536f 100644
--- a/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -475,7 +475,7 @@ void DwarfUnit::addBlockByrefAddress(const DbgVariable &DV, DIE &Die,
 
   SmallVector<uint64_t, 9> Ops;
   if (Location.isIndirect() && Location.getOffset()) {
-    Ops.push_back(dwarf::DW_OP_plus);
+    Ops.push_back(dwarf::DW_OP_plus_uconst);
     Ops.push_back(Location.getOffset());
   }
   // If we started with a pointer to the __Block_byref... struct, then
@@ -487,7 +487,7 @@ void DwarfUnit::addBlockByrefAddress(const DbgVariable &DV, DIE &Die,
   // DW_OP_plus_uconst ForwardingFieldOffset.  Note there's no point in
   // adding the offset if it's 0.
   if (forwardingFieldOffset > 0) {
-    Ops.push_back(dwarf::DW_OP_plus);
+    Ops.push_back(dwarf::DW_OP_plus_uconst);
     Ops.push_back(forwardingFieldOffset);
   }
 
@@ -499,7 +499,7 @@ void DwarfUnit::addBlockByrefAddress(const DbgVariable &DV, DIE &Die,
   // for the variable's field to get to the location of the actual variable:
   // DW_OP_plus_uconst varFieldOffset.  Again, don't add if it's 0.
   if (varFieldOffset > 0) {
-    Ops.push_back(dwarf::DW_OP_plus);
+    Ops.push_back(dwarf::DW_OP_plus_uconst);
     Ops.push_back(varFieldOffset);
   }
 
diff --git a/lib/IR/DebugInfoMetadata.cpp b/lib/IR/DebugInfoMetadata.cpp
index a34f8d9eac1..0bf68b4c53b 100644
--- a/lib/IR/DebugInfoMetadata.cpp
+++ b/lib/IR/DebugInfoMetadata.cpp
@@ -598,9 +598,7 @@ unsigned DIExpression::ExprOperand::getSize() const {
   case dwarf::DW_OP_LLVM_fragment:
     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:
     return 1;
@@ -666,11 +664,12 @@ DIExpression::getFragmentInfo(expr_op_iterator Start, expr_op_iterator End) {
 void DIExpression::appendOffset(SmallVectorImpl<uint64_t> &Ops,
                                 int64_t Offset) {
   if (Offset > 0) {
-    Ops.push_back(dwarf::DW_OP_plus);
+    Ops.push_back(dwarf::DW_OP_plus_uconst);
     Ops.push_back(Offset);
   } else if (Offset < 0) {
-    Ops.push_back(dwarf::DW_OP_minus);
+    Ops.push_back(dwarf::DW_OP_constu);
     Ops.push_back(-Offset);
+    Ops.push_back(dwarf::DW_OP_minus);
   }
 }
 
@@ -679,17 +678,23 @@ bool DIExpression::extractIfOffset(int64_t &Offset) const {
     Offset = 0;
     return true;
   }
-  if (getNumElements() != 2)
-    return false;
-  if (Elements[0] == dwarf::DW_OP_plus ||
-      Elements[0] == dwarf::DW_OP_plus_uconst) {
+
+  if (getNumElements() == 2 && Elements[0] == dwarf::DW_OP_plus_uconst) {
     Offset = Elements[1];
     return true;
   }
-  if (Elements[0] == dwarf::DW_OP_minus) {
-    Offset = -Elements[1];
-    return true;
+
+  if (getNumElements() == 3 && Elements[0] == dwarf::DW_OP_constu) {
+    if (Elements[2] == dwarf::DW_OP_plus) {
+      Offset = Elements[1];
+      return true;
+    }
+    if (Elements[2] == dwarf::DW_OP_minus) {
+      Offset = -Elements[1];
+      return true;
+    }
   }
+
   return false;
 }
 
diff --git a/lib/IR/Metadata.cpp b/lib/IR/Metadata.cpp
index 0b1bc9a8c27..92e5798dcf2 100644
--- a/lib/IR/Metadata.cpp
+++ b/lib/IR/Metadata.cpp
@@ -1470,7 +1470,7 @@ void GlobalObject::copyMetadata(const GlobalObject *Other, unsigned Offset) {
       if (E)
         OrigElements = E->getElements();
       std::vector<uint64_t> Elements(OrigElements.size() + 2);
-      Elements[0] = dwarf::DW_OP_plus;
+      Elements[0] = dwarf::DW_OP_plus_uconst;
       Elements[1] = Offset;
       std::copy(OrigElements.begin(), OrigElements.end(), Elements.begin() + 2);
       E = DIExpression::get(getContext(), Elements);
diff --git a/test/Assembler/diexpression.ll b/test/Assembler/diexpression.ll
index 7d2d45b8bd0..39f4be70145 100644
--- a/test/Assembler/diexpression.ll
+++ b/test/Assembler/diexpression.ll
@@ -6,15 +6,15 @@
 
 ; CHECK:      !0 = !DIExpression()
 ; CHECK-NEXT: !1 = !DIExpression(DW_OP_deref)
-; CHECK-NEXT: !2 = !DIExpression(DW_OP_plus, 3)
+; CHECK-NEXT: !2 = !DIExpression(DW_OP_constu, 3, DW_OP_plus)
 ; 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: !4 = !DIExpression(DW_OP_deref, DW_OP_plus_uconst, 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)
+!2 = !DIExpression(DW_OP_constu, 3, DW_OP_plus)
 !3 = !DIExpression(DW_OP_LLVM_fragment, 3, 7)
-!4 = !DIExpression(DW_OP_deref, DW_OP_plus, 3, DW_OP_LLVM_fragment, 3, 7)
+!4 = !DIExpression(DW_OP_deref, DW_OP_plus_uconst, 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)
diff --git a/test/Bitcode/DIExpression-deref.ll b/test/Bitcode/DIExpression-deref.ll
index 3a161b8ee4d..a03d6016523 100644
--- a/test/Bitcode/DIExpression-deref.ll
+++ b/test/Bitcode/DIExpression-deref.ll
@@ -11,11 +11,11 @@
 !5 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
 ; DW_OP_deref should be moved to the back of the expression.
 ;
-; CHECK: !DIExpression(DW_OP_plus, 0, DW_OP_deref, DW_OP_LLVM_fragment, 8, 32)
+; CHECK: !DIExpression(DW_OP_plus_uconst, 0, DW_OP_deref, DW_OP_LLVM_fragment, 8, 32)
 !6 = !DIExpression(DW_OP_deref, DW_OP_plus, 0, DW_OP_LLVM_fragment, 8, 32)
-; CHECK: !DIExpression(DW_OP_plus, 0, DW_OP_deref)
+; CHECK: !DIExpression(DW_OP_plus_uconst, 0, DW_OP_deref)
 !7 = !DIExpression(DW_OP_deref, DW_OP_plus, 0)
-; CHECK: !DIExpression(DW_OP_plus, 1, DW_OP_deref)
+; CHECK: !DIExpression(DW_OP_plus_uconst, 1, DW_OP_deref)
 !8 = !DIExpression(DW_OP_plus, 1, DW_OP_deref)
 ; CHECK: !DIExpression(DW_OP_deref)
 !9 = !DIExpression(DW_OP_deref)
diff --git a/test/Bitcode/DIExpression-minus-upgrade.ll b/test/Bitcode/DIExpression-minus-upgrade.ll
new file mode 100644
index 00000000000..1f26eba6f98
--- /dev/null
+++ b/test/Bitcode/DIExpression-minus-upgrade.ll
@@ -0,0 +1,16 @@
+; RUN: llvm-dis -o - %s.bc | FileCheck %s
+
+!llvm.dbg.cu = !{!1}
+!llvm.module.flags = !{!8, !9}
+
+!0 = distinct !DIGlobalVariable(name: "g", scope: !1, file: !2, line: 1, type: !5, isLocal: false, isDefinition: true)
+!1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2, producer: "clang (llvm/trunk 304286)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !3, globals: !4)
+!2 = !DIFile(filename: "a.c", directory: "/")
+!3 = !{}
+!4 = !{!7}
+!5 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+; CHECK: !DIExpression(DW_OP_constu, 42, DW_OP_minus)
+!6 = !DIExpression(DW_OP_minus, 42)
+!7 = !DIGlobalVariableExpression(var: !0, expr: !6)
+!8 = !{i32 2, !"Dwarf Version", i32 4}
+!9 = !{i32 2, !"Debug Info Version", i32 3}
diff --git a/test/Bitcode/DIExpression-minus-upgrade.ll.bc b/test/Bitcode/DIExpression-minus-upgrade.ll.bc
new file mode 100644
index 00000000000..354ba6454c3
Binary files /dev/null and b/test/Bitcode/DIExpression-minus-upgrade.ll.bc differ
diff --git a/test/Bitcode/DIGlobalVariableExpression.ll b/test/Bitcode/DIGlobalVariableExpression.ll
index f6796bbdb7a..31c3fda1b00 100644
--- a/test/Bitcode/DIGlobalVariableExpression.ll
+++ b/test/Bitcode/DIGlobalVariableExpression.ll
@@ -14,7 +14,7 @@
 ; CHECK: ![[HVAR:[0-9]+]] = distinct !DIGlobalVariable(name: "h",
 ; CHECK: ![[IMPORTS]] = !{![[CIMPORT:[0-9]+]]}
 ; CHECK: ![[CIMPORT]] = !DIImportedEntity({{.*}}entity: ![[HVAR]]
-; CHECK: ![[GEXPR]] = !DIExpression(DW_OP_plus, 1)
+; CHECK: ![[GEXPR]] = !DIExpression(DW_OP_plus_uconst, 1)
 ; CHECK: ![[H]] = {{.*}}!DIGlobalVariableExpression(var: ![[HVAR]])
 
 @g = common global i32 0, align 4, !dbg !0
diff --git a/test/CodeGen/ARM/debug-info-blocks.ll b/test/CodeGen/ARM/debug-info-blocks.ll
index 1e9d890e933..6019a9410b0 100644
--- a/test/CodeGen/ARM/debug-info-blocks.ll
+++ b/test/CodeGen/ARM/debug-info-blocks.ll
@@ -273,6 +273,6 @@ define hidden void @foobar_func_block_invoke_0(i8* %.block_descriptor, %0* %load
 !160 = !DIFile(filename: "header.h", directory: "/Volumes/Sandbox/llvm")
 !161 = !{!"header2.h", !"/Volumes/Sandbox/llvm"}
 !162 = !{i32 1, !"Debug Info Version", i32 3}
-!163 = !DIExpression(DW_OP_plus, 20, DW_OP_deref, DW_OP_plus, 4, DW_OP_deref, DW_OP_plus, 24)
-!164 = !DIExpression(DW_OP_deref, DW_OP_plus, 24)
-!165 = !DIExpression(DW_OP_deref, DW_OP_plus, 28)
+!163 = !DIExpression(DW_OP_plus_uconst, 20, DW_OP_deref, DW_OP_plus_uconst, 4, DW_OP_deref, DW_OP_plus_uconst, 24)
+!164 = !DIExpression(DW_OP_deref, DW_OP_plus_uconst, 24)
+!165 = !DIExpression(DW_OP_deref, DW_OP_plus_uconst, 28)
diff --git a/test/CodeGen/X86/lea-opt-with-debug.mir b/test/CodeGen/X86/lea-opt-with-debug.mir
index 0a477706df1..03a745888b5 100644
--- a/test/CodeGen/X86/lea-opt-with-debug.mir
+++ b/test/CodeGen/X86/lea-opt-with-debug.mir
@@ -49,7 +49,7 @@
   !5 = !{i32 2, !"Dwarf Version", i32 4}
   !6 = !{i32 2, !"Debug Info Version", i32 3}
   !7 = !{i32 1, !"PIC Level", i32 2}
-  !8 = !DIExpression(DW_OP_plus, 8, DW_OP_stack_value)
+  !8 = !DIExpression(DW_OP_plus_uconst, 8, DW_OP_stack_value)
   !9 = distinct !DISubprogram(name: "fn1", scope: !1, file: !1, line: 7, type: !10, isLocal: false, isDefinition: true, scopeLine: 7, isOptimized: true, unit: !0, variables: !11)
   !10 = !DISubroutineType(types: !3)
   !11 = !{!12}
diff --git a/test/DebugInfo/Generic/block-asan.ll b/test/DebugInfo/Generic/block-asan.ll
index f1f8b35df27..73df59bf3d5 100644
--- a/test/DebugInfo/Generic/block-asan.ll
+++ b/test/DebugInfo/Generic/block-asan.ll
@@ -13,7 +13,7 @@
 
 ; Check that the location of the ASAN instrumented __block variable is
 ; correct.
-; CHECK: !DIExpression(DW_OP_plus, 8, DW_OP_deref, DW_OP_plus, 24)
+; CHECK: !DIExpression(DW_OP_plus_uconst, 8, DW_OP_deref, DW_OP_plus_uconst, 24)
 
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
 
@@ -79,7 +79,7 @@ attributes #3 = { nounwind }
 !19 = !DIBasicType(tag: DW_TAG_base_type, name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
 !20 = !DIDerivedType(tag: DW_TAG_member, name: "__size", size: 32, align: 32, offset: 160, file: !1, scope: !5, baseType: !19)
 !21 = !DIDerivedType(tag: DW_TAG_member, name: "x", size: 32, align: 32, offset: 192, file: !1, scope: !5, baseType: !19)
-!22 = !DIExpression(DW_OP_plus, 8, DW_OP_deref, DW_OP_plus, 24)
+!22 = !DIExpression(DW_OP_plus_uconst, 8, DW_OP_deref, DW_OP_plus_uconst, 24)
 !23 = !DILocation(line: 4, column: 15, scope: !4)
 !24 = !DILocation(line: 4, column: 3, scope: !4)
 !25 = !DILocation(line: 5, column: 3, scope: !4)
diff --git a/test/DebugInfo/MIR/ARM/split-superreg-complex.mir b/test/DebugInfo/MIR/ARM/split-superreg-complex.mir
index 2e8d9977a64..0ebde3c1eb3 100644
--- a/test/DebugInfo/MIR/ARM/split-superreg-complex.mir
+++ b/test/DebugInfo/MIR/ARM/split-superreg-complex.mir
@@ -57,7 +57,7 @@
   !17 = !{!18}
   !18 = !DISubrange(count: 4)
   !19 = !DILocation(line: 4, column: 13, scope: !9)
-  !20 = !DIExpression(DW_OP_plus, 1, DW_OP_minus, 1)
+  !20 = !DIExpression(DW_OP_plus_uconst, 1, DW_OP_constu, 1, DW_OP_minus)
   !21 = !DILocation(line: 4, column: 7, scope: !9)
   !22 = !DILocation(line: 5, column: 9, scope: !9)
   !23 = !DILocation(line: 5, column: 18, scope: !9)
diff --git a/test/DebugInfo/X86/block-capture.ll b/test/DebugInfo/X86/block-capture.ll
index 168040507ee..14927eef59d 100644
--- a/test/DebugInfo/X86/block-capture.ll
+++ b/test/DebugInfo/X86/block-capture.ll
@@ -123,7 +123,7 @@ attributes #3 = { nounwind }
 !66 = !DILocation(line: 2, column: 20, scope: !8)
 !67 = !DILocation(line: 2, column: 21, scope: !8)
 !68 = !DILocalVariable(name: "block", line: 2, scope: !8, file: !5, type: !25)
-!69 = !DIExpression(DW_OP_deref, DW_OP_plus, 32)
+!69 = !DIExpression(DW_OP_deref, DW_OP_plus_uconst, 32)
 !70 = !DILocation(line: 2, column: 9, scope: !8)
 !71 = !DILocation(line: 2, column: 23, scope: !72)
 !72 = distinct !DILexicalBlock(line: 2, column: 21, file: !1, scope: !8)
diff --git a/test/DebugInfo/X86/debug-info-block-captured-self.ll b/test/DebugInfo/X86/debug-info-block-captured-self.ll
index 1085eaef0d4..e1620af5025 100644
--- a/test/DebugInfo/X86/debug-info-block-captured-self.ll
+++ b/test/DebugInfo/X86/debug-info-block-captured-self.ll
@@ -107,5 +107,5 @@ define internal void @"__24-[Main initWithContext:]_block_invoke_2"(i8* %.block_
 !106 = !DILocation(line: 40, scope: !42)
 !107 = !DIFile(filename: "llvm/tools/clang/test/CodeGenObjC/debug-info-block-captured-self.m", directory: "")
 !108 = !{i32 1, !"Debug Info Version", i32 3}
-!109 = !DIExpression(DW_OP_plus, 32, DW_OP_deref)
-!110 = !DIExpression(DW_OP_plus, 32, DW_OP_deref)
+!109 = !DIExpression(DW_OP_plus_uconst, 32, DW_OP_deref)
+!110 = !DIExpression(DW_OP_plus_uconst, 32, DW_OP_deref)
diff --git a/test/DebugInfo/X86/debug-info-blocks.ll b/test/DebugInfo/X86/debug-info-blocks.ll
index 859eef804bb..b79ad89be27 100644
--- a/test/DebugInfo/X86/debug-info-blocks.ll
+++ b/test/DebugInfo/X86/debug-info-blocks.ll
@@ -380,4 +380,4 @@ attributes #3 = { nounwind }
 !108 = !DILocation(line: 61, scope: !36)
 !109 = !DILocation(line: 62, scope: !36)
 !110 = !{i32 1, !"Debug Info Version", i32 3}
-!111 = !DIExpression(DW_OP_deref, DW_OP_plus, 32)
+!111 = !DIExpression(DW_OP_deref, DW_OP_plus_uconst, 32)
diff --git a/test/DebugInfo/X86/dw_op_minus.ll b/test/DebugInfo/X86/dw_op_minus.ll
index 8e65b489c27..30bf5837800 100644
--- a/test/DebugInfo/X86/dw_op_minus.ll
+++ b/test/DebugInfo/X86/dw_op_minus.ll
@@ -10,7 +10,7 @@
 ;   Capture(buf);
 ; }
 ; }
-; The interesting part is !DIExpression(DW_OP_minus, 400)
+; The interesting part is !DIExpression(DW_OP_constu, 400, DW_OP_minus)
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
@@ -56,7 +56,7 @@ declare void @Capture(i32*)
 !14 = !{i32 2, !"Debug Info Version", i32 3}
 !15 = !{!"clang version 3.8.0 (trunk 248518) (llvm/trunk 248512)"}
 !16 = !DILocation(line: 5, column: 3, scope: !4)
-!17 = !DIExpression(DW_OP_minus, 400)
+!17 = !DIExpression(DW_OP_constu, 400, DW_OP_minus)
 !18 = !DILocation(line: 5, column: 7, scope: !4)
 !19 = !DILocation(line: 6, column: 11, scope: !4)
 !20 = !DILocation(line: 6, column: 3, scope: !4)
diff --git a/test/DebugInfo/X86/dw_op_minus_direct.ll b/test/DebugInfo/X86/dw_op_minus_direct.ll
index 8d346be532e..69f4b2c3ef6 100644
--- a/test/DebugInfo/X86/dw_op_minus_direct.ll
+++ b/test/DebugInfo/X86/dw_op_minus_direct.ll
@@ -51,7 +51,7 @@ attributes #1 = { nounwind readnone }
 !10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
 !11 = !{!12}
 !12 = !DILocalVariable(name: "i", arg: 1, scope: !7, file: !1, line: 1, type: !10)
-!13 = !DIExpression(DW_OP_minus, 1, DW_OP_stack_value)
+!13 = !DIExpression(DW_OP_constu, 1, DW_OP_minus, DW_OP_stack_value)
 !14 = !DILocation(line: 1, column: 13, scope: !7)
 !15 = !DILocation(line: 2, column: 11, scope: !7)
 !16 = !DILocation(line: 2, column: 3, scope: !7)
diff --git a/test/DebugInfo/X86/safestack-byval.ll b/test/DebugInfo/X86/safestack-byval.ll
index 42e94698818..8742c90bc29 100644
--- a/test/DebugInfo/X86/safestack-byval.ll
+++ b/test/DebugInfo/X86/safestack-byval.ll
@@ -14,7 +14,7 @@
 ; }
 
 ; CHECK: ![[ZZZ:.*]] = !DILocalVariable(name: "zzz",
-; CHECK: ![[ZZZ_EXPR:.*]] = !DIExpression(DW_OP_deref, DW_OP_minus, 400)
+; CHECK: ![[ZZZ_EXPR:.*]] = !DIExpression(DW_OP_deref, DW_OP_constu, 400, DW_OP_minus)
 ; CHECK: DBG_VALUE {{.*}} ![[ZZZ]], ![[ZZZ_EXPR]]
 
 %struct.S = type { [100 x i32] }
@@ -79,7 +79,7 @@ attributes #2 = { argmemonly nounwind }
 !20 = !{i32 2, !"Debug Info Version", i32 3}
 !21 = !{!"clang version 3.8.0 (trunk 254107) (llvm/trunk 254109)"}
 !22 = !DILocation(line: 8, column: 9, scope: !12)
-!23 = !DIExpression(DW_OP_deref, DW_OP_minus, 400)
+!23 = !DIExpression(DW_OP_deref, DW_OP_constu, 400, DW_OP_minus)
 !24 = !DILocation(line: 8, column: 28, scope: !12)
 !25 = !DIExpression()
 !26 = !DILocation(line: 9, column: 10, scope: !12)
diff --git a/test/DebugInfo/X86/stack-value-dwarf2.ll b/test/DebugInfo/X86/stack-value-dwarf2.ll
index 61595f7861f..b653784ec66 100644
--- a/test/DebugInfo/X86/stack-value-dwarf2.ll
+++ b/test/DebugInfo/X86/stack-value-dwarf2.ll
@@ -93,4 +93,4 @@ attributes #1 = { nounwind readnone }
 !15 = !DISubprogram(name: "<(lambda at test.ii:87:58)>", scope: !0, file: !1, line: 27, type: !6, isLocal: false, isDefinition: false, scopeLine: 27, flags: DIFlagPublic | DIFlagPrototyped, isOptimized: true, templateParams: !2)
 !16 = distinct !DILocation(line: 99, column: 21, scope: !17)
 !17 = !DILexicalBlockFile(scope: !5, file: !1, discriminator: 2)
-!18 = !DIExpression(DW_OP_plus, 4, DW_OP_stack_value, DW_OP_LLVM_fragment, 64, 32)
+!18 = !DIExpression(DW_OP_plus_uconst, 4, DW_OP_stack_value, DW_OP_LLVM_fragment, 64, 32)
diff --git a/test/DebugInfo/X86/unattached-global.ll b/test/DebugInfo/X86/unattached-global.ll
index 5d4be7377ef..5e9af695c8d 100644
--- a/test/DebugInfo/X86/unattached-global.ll
+++ b/test/DebugInfo/X86/unattached-global.ll
@@ -12,7 +12,7 @@ target triple = "x86_64-unknown-linux-gnu"
 !1 = !{!2}
 !2 = !DIGlobalVariableExpression(var: !3, expr: !4)
 !3 = distinct !DIGlobalVariable(name: "a", scope: null, isLocal: false, isDefinition: true, type: !6)
-!4 = !DIExpression(DW_OP_plus, 4)
+!4 = !DIExpression(DW_OP_plus_uconst, 4)
 !5 = !DIFile(filename: "<stdin>", directory: "/")
 !6 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
 
diff --git a/test/Transforms/GlobalMerge/debug-info.ll b/test/Transforms/GlobalMerge/debug-info.ll
index 97e0bb2148e..8d60f366243 100644
--- a/test/Transforms/GlobalMerge/debug-info.ll
+++ b/test/Transforms/GlobalMerge/debug-info.ll
@@ -17,7 +17,7 @@ define void @use1() {
 ; CHECK: [[AVAR]] = !DIGlobalVariable(name: "a", scope: null, isLocal: false, isDefinition: true)
 ; CHECK: [[B]] = !DIGlobalVariableExpression(var: [[BVAR:![0-9]+]], expr: [[EXPR:![0-9]+]])
 ; CHECK: [[BVAR]] = !DIGlobalVariable(name: "b", scope: null, isLocal: false, isDefinition: true)
-; CHECK: [[EXPR]] = !DIExpression(DW_OP_plus, 4)
+; CHECK: [[EXPR]] = !DIExpression(DW_OP_plus_uconst, 4)
 
 !llvm.module.flags = !{!4, !5}
 
diff --git a/test/Transforms/InstCombine/debuginfo-dce.ll b/test/Transforms/InstCombine/debuginfo-dce.ll
index 086743e8082..50b8f1c6068 100644
--- a/test/Transforms/InstCombine/debuginfo-dce.ll
+++ b/test/Transforms/InstCombine/debuginfo-dce.ll
@@ -93,12 +93,12 @@ entry:
   ret void, !dbg !32
 }
 
-; CHECK: ![[LOAD_EXPR]] = !DIExpression(DW_OP_deref, DW_OP_plus, 0)
-; CHECK: ![[BITCAST_EXPR]] = !DIExpression(DW_OP_plus, 0)
-; CHECK: ![[GEP0_EXPR]] = !DIExpression(DW_OP_minus, 8, DW_OP_plus, 0, DW_OP_stack_value)
-; CHECK: ![[GEP1_EXPR]] = !DIExpression(DW_OP_minus, 8, DW_OP_stack_value,
+; CHECK: ![[LOAD_EXPR]] = !DIExpression(DW_OP_deref, DW_OP_plus_uconst, 0)
+; CHECK: ![[BITCAST_EXPR]] = !DIExpression(DW_OP_plus_uconst, 0)
+; CHECK: ![[GEP0_EXPR]] = !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_plus_uconst, 0, DW_OP_stack_value)
+; CHECK: ![[GEP1_EXPR]] = !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_stack_value,
 ; CHECK-SAME:                           DW_OP_LLVM_fragment, 0, 32)
-; CHECK: ![[GEP2_EXPR]] = !DIExpression(DW_OP_minus, 8, DW_OP_stack_value)
+; CHECK: ![[GEP2_EXPR]] = !DIExpression(DW_OP_constu, 8, DW_OP_minus, DW_OP_stack_value)
 
 ; Function Attrs: nounwind readnone
 declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #1
@@ -130,7 +130,7 @@ attributes #1 = { nounwind readnone }
 !17 = !{!18}
 !18 = !DILocalVariable(name: "entry", scope: !14, file: !1, line: 6, type: !4)
 !19 = !DILocation(line: 6, column: 17, scope: !14)
-!20 = !DIExpression(DW_OP_plus, 0)
+!20 = !DIExpression(DW_OP_plus_uconst, 0)
 !21 = !DILocation(line: 11, column: 1, scope: !14)
 !22 = distinct !DISubprogram(name: "scan", scope: !1, file: !1, line: 4, type: !15, isLocal: false, isDefinition: true, scopeLine: 5, flags: DIFlagPrototyped, isOptimized: true, unit: !0, variables: !17)
 !23 = !DILocation(line: 6, column: 17, scope: !22)
diff --git a/test/Transforms/SafeStack/X86/debug-loc.ll b/test/Transforms/SafeStack/X86/debug-loc.ll
index 88cda693b29..d6b217142bf 100644
--- a/test/Transforms/SafeStack/X86/debug-loc.ll
+++ b/test/Transforms/SafeStack/X86/debug-loc.ll
@@ -37,10 +37,10 @@ entry:
 
 ; CHECK-DAG: ![[VAR_ARG]] = !DILocalVariable(name: "zzz"
 ; 100 aligned up to 8
-; CHECK-DAG: ![[EXPR_ARG]] = !DIExpression(DW_OP_minus, 104)
+; CHECK-DAG: ![[EXPR_ARG]] = !DIExpression(DW_OP_constu, 104, DW_OP_minus
 
 ; CHECK-DAG: ![[VAR_LOCAL]] = !DILocalVariable(name: "xxx"
-; CHECK-DAG: ![[EXPR_LOCAL]] = !DIExpression(DW_OP_minus, 208)
+; CHECK-DAG: ![[EXPR_LOCAL]] = !DIExpression(DW_OP_constu, 208, DW_OP_minus
 
 ; Function Attrs: nounwind readnone
 declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
diff --git a/test/Transforms/SafeStack/X86/debug-loc2.ll b/test/Transforms/SafeStack/X86/debug-loc2.ll
index 8059a722fd4..731516c3c65 100644
--- a/test/Transforms/SafeStack/X86/debug-loc2.ll
+++ b/test/Transforms/SafeStack/X86/debug-loc2.ll
@@ -84,8 +84,8 @@ attributes #4 = { nounwind }
 !13 = !DILocation(line: 5, column: 3, scope: !6)
 !14 = !DILocation(line: 6, column: 3, scope: !6)
 
-; CHECK-DAG: ![[X1_EXPR]] = !DIExpression(DW_OP_deref, DW_OP_minus, 4)
-; CHECK-DAG: ![[X2_EXPR]] = !DIExpression(DW_OP_deref, DW_OP_minus, 8)
+; CHECK-DAG: ![[X1_EXPR]] = !DIExpression(DW_OP_deref, DW_OP_constu, 4, DW_OP_minus)
+; CHECK-DAG: ![[X2_EXPR]] = !DIExpression(DW_OP_deref, DW_OP_constu, 8, DW_OP_minus)
 !15 = !DIExpression(DW_OP_deref)
 !16 = !DILocation(line: 5, column: 7, scope: !6)
 !17 = !DILocation(line: 8, column: 3, scope: !6)
@@ -95,4 +95,4 @@ attributes #4 = { nounwind }
 !21 = !DILocation(line: 10, column: 1, scope: !22)
 !22 = !DILexicalBlockFile(scope: !6, file: !1, discriminator: 1)
 !23 = !DIExpression()
-!24 = !DIExpression(DW_OP_minus, 42)
+!24 = !DIExpression(DW_OP_constu, 42, DW_OP_minus)
diff --git a/unittests/IR/MetadataTest.cpp b/unittests/IR/MetadataTest.cpp
index a09a4239ec4..cb38b30f43e 100644
--- a/unittests/IR/MetadataTest.cpp
+++ b/unittests/IR/MetadataTest.cpp
@@ -2042,23 +2042,23 @@ TEST_F(DIExpressionTest, isValid) {
   EXPECT_TRUE(DIExpression::get(Context, None));
 
   // Valid constructions.
-  EXPECT_VALID(dwarf::DW_OP_plus, 6);
   EXPECT_VALID(dwarf::DW_OP_plus_uconst, 6);
+  EXPECT_VALID(dwarf::DW_OP_constu, 6, dwarf::DW_OP_plus);
   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);
-  EXPECT_VALID(dwarf::DW_OP_deref, dwarf::DW_OP_plus, 6);
+  EXPECT_VALID(dwarf::DW_OP_plus_uconst, 6, dwarf::DW_OP_deref);
+  EXPECT_VALID(dwarf::DW_OP_deref, dwarf::DW_OP_plus_uconst, 6);
   EXPECT_VALID(dwarf::DW_OP_deref, dwarf::DW_OP_LLVM_fragment, 3, 7);
-  EXPECT_VALID(dwarf::DW_OP_deref, dwarf::DW_OP_plus, 6,
+  EXPECT_VALID(dwarf::DW_OP_deref, dwarf::DW_OP_plus_uconst, 6,
                dwarf::DW_OP_LLVM_fragment, 3, 7);
 
   // Invalid constructions.
   EXPECT_INVALID(~0u);
-  EXPECT_INVALID(dwarf::DW_OP_plus);
+  EXPECT_INVALID(dwarf::DW_OP_plus, 0);
   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);
+  EXPECT_INVALID(dwarf::DW_OP_LLVM_fragment, 3, 7, dwarf::DW_OP_plus_uconst, 3);
   EXPECT_INVALID(dwarf::DW_OP_LLVM_fragment, 3, 7, dwarf::DW_OP_deref);
 
 #undef EXPECT_VALID