Move the IsIndirect flag from DIVariable into DIExpression.

[aprantl]

Summary

This has been long overdue, and is generally totally mechanical. It does break IR-Metadata compatibility, but we do that a lot at the moment :-)

In this form I'm taking no prisoners and simple reflow DIDescriptor::FlagLValueReference and FlagRValueReference to close the gap from removing the flag, but I could understand if someone rather wants to leave a hole in the enum.

Note: LLVM+CFE is rolled into one patch.

Commit message:

Move the IsIndirect flag from DIVariable into DIExpression.
This is a much more natural place for this information to be, but there
is also a more technical reason:

The IsIndirect flag is used to mark a variable that is turned
into a reference by virtue of the calling convention; this happends
for example to aggregate return values.
The inliner, for example, may actually need to undo this indirection to
correctly represent the value in its new context. This is impossible to
implement because the DIVariable can't be safely modified. We can however
safely construct a new DIExpression on the fly.

[aprantl]

• msg-25009-212.txt1 KBDownload
• test.ll5 KBDownload

[dblaikie]

(might be easier to review/commit by adding the expression handling then just removing the flag as dead code afterwards, but I'm not sure - it's not bad the way you've got it either)

lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp

237

Do we need MachineLocation::isIndirect anymore?

Hmm, I guess I do vaguely recall this being here before I added the other indirect flag... but I forget what it might be for, etc.

[aprantl]

In D6986#109826, @dblaikie wrote:

(might be easier to review/commit by adding the expression handling then just removing the flag as dead code afterwards, but I'm not sure - it's not bad the way you've got it either)

Oh that would be great, but it's complicated:
After having read http://reviews.llvm.org/D7016, look at this gem from SelectionDAGBuilder:

uint64_t Offset = DI->getOffset();
  // A dbg.value for an alloca is always indirect.
  bool IsIndirect = isa<AllocaInst>(V) || Offset != 0;
  SDDbgValue *SDV;
  if (Val.getNode()) {
    if (!EmitFuncArgumentDbgValue(V, Variable, Expr, Offset, IsIndirect,
                                  Val)) {
      SDV = DAG.getDbgValue(Variable, Expr, Val.getNode(), Val.getResNo(),
                            IsIndirect, Offset, dl, DbgSDNodeOrder);
      DAG.AddDbgValue(SDV, Val.getNode(), false);
    }
  } else

It is rematerializing the OP_deref that this patch removes in the form a of an indirect MachineLocation.

Horrible, right?

We could get rid of the indirect field in MachineLocation, if we were to redefine alloca's to be treated as addresses rather than values in dbg.value/dbg.declare.
Let me give an example. Currently, the following code:

%x = alloca i64
call void @llvm.dbg.declare(metadata %i64* %x, [var=x], [expr=[]])
store i64 42, %x

is lowered into

%x = i64 42
call void @llvm.dbg.value(metadata %i64* %x, [var=x], [expr=[]])

Observe that the alloca, although it is treated like an address in IR, is treated like it was the value as far as the debug info is concerned.
If we want to fix this we'd have to change the frontend to emit

%x = alloca i64
call void @llvm.dbg.declare(metadata %i64* %x, [var=x], [expr=[DW_OP_deref]])
store i64 42, %x

which could then be lowered into the same code as above. After separating out DIExpression from DIVariable this is really easy to do; before it was pretty much impossible.

I think I'd love to do that instead. Should we go break stuff? ;-)

[aprantl]

[I also feel that need to apologize for adding the indirect field to MachineLocation in the first place; but I was much more reluctant to changing the IR semantics back then than I am now.]

[aprantl]

that was committed in r226476.

[aprantl]

that was committed in r226476.

include/llvm/CodeGen/AsmPrinter.h

 
   /// EmitDwarfRegOp - Emit a dwarf register operation.
   /// \param Indirect   whether this is a register-indirect address
-  virtual void EmitDwarfRegOp(ByteStreamer &BS, const MachineLocation &MLoc,
-                              bool Indirect) const;
+  virtual void EmitDwarfRegOp(ByteStreamer &BS,
+                              const MachineLocation &MLoc) const;
 
   //===------------------------------------------------------------------===//
   // Dwarf Lowering Routines

include/llvm/IR/DebugInfo.h

     FlagObjectPointer     = 1 << 10,
     FlagVector            = 1 << 11,
     FlagStaticMember      = 1 << 12,
-    FlagIndirectVariable  = 1 << 13,
-    FlagLValueReference   = 1 << 14,
-    FlagRValueReference   = 1 << 15
+    FlagLValueReference   = 1 << 13,
+    FlagRValueReference   = 1 << 14
   };
 
 protected:

     return (getHeaderFieldAs<unsigned>(3) & FlagObjectPointer) != 0;
   }
 
-  /// \brief Return true if this variable is represented as a pointer.
-  bool isIndirect() const {
-    return (getHeaderFieldAs<unsigned>(3) & FlagIndirectVariable) != 0;
-  }
-
   /// \brief If this variable is inlined then return inline location.
   MDNode *getInlinedAt() const;
 

lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp

 
 /// EmitDwarfRegOp - Emit dwarf register operation.
 void AsmPrinter::EmitDwarfRegOp(ByteStreamer &Streamer,
-                                const MachineLocation &MLoc,
-                                bool Indirect) const {
+                                const MachineLocation &MLoc) const {
   DebugLocDwarfExpression Expr(*this, Streamer);
   const TargetRegisterInfo *TRI = TM.getSubtargetImpl()->getRegisterInfo();
   int Reg = TRI->getDwarfRegNum(MLoc.getReg(), false);
   if (Reg < 0) {
     // We assume that pointers are always in an addressable register.
-    if (Indirect || MLoc.isIndirect())
+    if (MLoc.isIndirect())
       // FIXME: We have no reasonable way of handling errors in here. The
       // caller might be in the middle of a dwarf expression. We should
       // probably assert that Reg >= 0 once debug info generation is more

   }
 
   if (MLoc.isIndirect())
-    Expr.AddRegIndirect(Reg, MLoc.getOffset(), Indirect);
-  else if (Indirect)
-    Expr.AddRegIndirect(Reg, 0, false);
+    Expr.AddRegIndirect(Reg, MLoc.getOffset());
   else
     Expr.AddReg(Reg);
 }

lib/CodeGen/AsmPrinter/DwarfCompileUnit.h

                           MachineLocation Location);
   /// Add an address attribute to a die based on the location provided.
   void addAddress(DIE &Die, dwarf::Attribute Attribute,
-                  const MachineLocation &Location, bool Indirect = false);
+                  const MachineLocation &Location);
 
   /// Start with the address based on the location provided, and generate the
   /// DWARF information necessary to find the actual variable (navigating the

lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp

   else if (DV.isBlockByrefVariable())
     addBlockByrefAddress(DV, Die, dwarf::DW_AT_location, Location);
   else
-    addAddress(Die, dwarf::DW_AT_location, Location,
-               DV.getVariable().isIndirect());
+    addAddress(Die, dwarf::DW_AT_location, Location);
 }
 
 /// Add an address attribute to a die based on the location provided.
 void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
-                                  const MachineLocation &Location,
-                                  bool Indirect) {
+                                  const MachineLocation &Location) {
   DIELoc *Loc = new (DIEValueAllocator) DIELoc();
 
   bool validReg;
-  if (Location.isReg() && !Indirect)
+  if (Location.isReg())
     validReg = addRegisterOpPiece(*Loc, Location.getReg());
   else
     validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());

   if (!validReg)
     return;
 
-  if (!Location.isReg() && Indirect)
-    addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
-
   // Now attach the location information to the DIE.
   addBlock(Die, Attribute, Loc);
 }

   DIExpression Expr = DV.getExpression();
   if (Location.getOffset()) {
     if (DwarfExpr.AddMachineRegIndirect(Location.getReg(),
-                                        Location.getOffset())) {
+                                        Location.getOffset()))
       DwarfExpr.AddExpression(Expr);
-      assert(!DV.getVariable().isIndirect()
-             && "double indirection not handled");
-    }
-  } else {
-    if (DwarfExpr.AddMachineRegExpression(Expr, Location.getReg()))
-      if (DV.getVariable().isIndirect())
-        DwarfExpr.EmitOp(dwarf::DW_OP_deref);
-  }
+  } else
+    DwarfExpr.AddMachineRegExpression(Expr, Location.getReg());
 
   // Now attach the location information to the DIE.
   addBlock(Die, Attribute, Loc);

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

 
 #ifndef NDEBUG
     DIVariable Var = Piece.getVariable();
-    assert(!Var.isIndirect() && "indirect address for piece");
     unsigned VarSize = Var.getSizeInBits(Map);
     assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
            && "piece is larger than or outside of variable");
     assert(PieceSize*SizeOfByte != VarSize
            && "piece covers entire variable");
 #endif
-
     emitDebugLocValue(Streamer, Piece, PieceOffset*SizeOfByte);
   }
 }

     DIExpression Expr = Value.getExpression();
     if (!Expr || (Expr.getNumElements() == 0))
       // Regular entry.
-      Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
+      Asm->EmitDwarfRegOp(Streamer, Loc);
     else {
       // Complex address entry.
       if (Loc.getOffset()) {

       } else
         DwarfExpr.AddMachineRegExpression(Expr, Loc.getReg(),
                                           PieceOffsetInBits);
-      if (DV.isIndirect())
-        DwarfExpr.EmitOp(dwarf::DW_OP_deref);
     }
   }
   // else ... ignore constant fp. There is not any good way to

lib/CodeGen/CGDebugInfo.cpp

     Line = getLineNumber(VD->getLocation());
     Column = getColumnNumber(VD->getLocation());
   }
+  SmallVector<int64_t, 9> Expr;
   unsigned Flags = 0;
   if (VD->isImplicit())
     Flags |= llvm::DIDescriptor::FlagArtificial;

   if (llvm::Argument *Arg = dyn_cast<llvm::Argument>(Storage))
     if (Arg->getType()->isPointerTy() && !Arg->hasByValAttr() &&
         !VD->getType()->isPointerType())
-      Flags |= llvm::DIDescriptor::FlagIndirectVariable;
+      Expr.push_back(llvm::dwarf::DW_OP_deref);
 
   llvm::MDNode *Scope = LexicalBlockStack.back();
 

   if (!Name.empty()) {
     if (VD->hasAttr<BlocksAttr>()) {
       CharUnits offset = CharUnits::fromQuantity(32);
-      SmallVector<int64_t, 9> addr;
-      addr.push_back(llvm::dwarf::DW_OP_plus);
+      Expr.push_back(llvm::dwarf::DW_OP_plus);
       // offset of __forwarding field
       offset = CGM.getContext().toCharUnitsFromBits(
           CGM.getTarget().getPointerWidth(0));
-      addr.push_back(offset.getQuantity());
-      addr.push_back(llvm::dwarf::DW_OP_deref);
-      addr.push_back(llvm::dwarf::DW_OP_plus);
+      Expr.push_back(offset.getQuantity());
+      Expr.push_back(llvm::dwarf::DW_OP_deref);
+      Expr.push_back(llvm::dwarf::DW_OP_plus);
       // offset of x field
       offset = CGM.getContext().toCharUnitsFromBits(XOffset);
-      addr.push_back(offset.getQuantity());
+      Expr.push_back(offset.getQuantity());
 
       // Create the descriptor for the variable.
       llvm::DIVariable D = DBuilder.createLocalVariable(

 
       // Insert an llvm.dbg.declare into the current block.
       llvm::Instruction *Call =
-          DBuilder.insertDeclare(Storage, D, DBuilder.createExpression(addr),
+          DBuilder.insertDeclare(Storage, D, DBuilder.createExpression(Expr),
                                  Builder.GetInsertBlock());
       Call->setDebugLoc(llvm::DebugLoc::get(Line, Column, Scope));
       return;
     } else if (isa<VariableArrayType>(VD->getType()))
-      Flags |= llvm::DIDescriptor::FlagIndirectVariable;
+      Expr.push_back(llvm::dwarf::DW_OP_deref);
   } else if (const RecordType *RT = dyn_cast<RecordType>(VD->getType())) {
     // If VD is an anonymous union then Storage represents value for
     // all union fields.

 
         // Insert an llvm.dbg.declare into the current block.
         llvm::Instruction *Call = DBuilder.insertDeclare(
-            Storage, D, DBuilder.createExpression(), Builder.GetInsertBlock());
+            Storage, D, DBuilder.createExpression(Expr),
+            Builder.GetInsertBlock());
         Call->setDebugLoc(llvm::DebugLoc::get(Line, Column, Scope));
       }
       return;

 
   // Insert an llvm.dbg.declare into the current block.
   llvm::Instruction *Call = DBuilder.insertDeclare(
-      Storage, D, DBuilder.createExpression(), Builder.GetInsertBlock());
+      Storage, D, DBuilder.createExpression(Expr), Builder.GetInsertBlock());
   Call->setDebugLoc(llvm::DebugLoc::get(Line, Column, Scope));
 }
 

test/CodeGen/debug-info-vla.c

 
 void testVLAwithSize(int s)
 {
-// CHECK:  !"0x100\00vla\00[[@LINE+1]]\008192", {{.*}}, {{.*}}, {{.*}}} ; [ DW_TAG_auto_variable ] [vla] [line [[@LINE+1]]]
+// CHECK: dbg.declare
+// CHECK: dbg.declare({{.*}}, metadata ![[VAR:.*]], metadata ![[EXPR:.*]])
+// CHECK: ![[VAR]] = {{.*}} ; [ DW_TAG_auto_variable ] [vla] [line [[@LINE+2]]]
+// CHECK: ![[EXPR]] = {{.*}} ; [ DW_TAG_expression ] [DW_OP_deref]
   int vla[s];
   int i;
   for (i = 0; i < s; i++) {

test/CodeGenCXX/debug-info.cpp

   }
 }
 
+// CHECK: define void @_ZN7pr147634funcENS_3fooE
+// CHECK: call void @llvm.dbg.declare({{.*}}, metadata ![[F:.*]], metadata ![[EXPR:.*]])
+
 // MSVC: [[VBASE_B:![0-9]+]] = distinct !{!"0x13\00B\00{{[0-9]+}}\0096\0032\000\000\000", {{.*}}, null, [[VBASE_B_DEF:![0-9]+]], {{.*}}} ; [ DW_TAG_structure_type ] [B] [line 49, size 96, align 32, offset 0] [def] [from ]
 // MSVC: [[VBASE_B_DEF]] = !{[[VBASE_A_IN_B:![0-9]+]],
 //

 }
 
 // For some reason function arguments ended up down here
-// CHECK: = !{!"0x101\00f\00{{.*}}\008192", [[FUNC]], {{![0-9]+}}, !"[[FOO]]"} ; [ DW_TAG_arg_variable ] [f]
+// CHECK: ![[F]] = !{!"0x101\00f\00{{.*}}\000", [[FUNC]], {{![0-9]+}}, !"[[FOO]]"} ; [ DW_TAG_arg_variable ] [f]
+// CHECK: ![[EXPR]] = {{.*}} ; [ DW_TAG_expression ] [DW_OP_deref]
 
 // CHECK: ; [ DW_TAG_auto_variable ] [c]
 

test/DebugInfo/AArch64/struct_by_value.ll

 ; Function Attrs: nounwind ssp
 define i32 @return_five_int(%struct.five* %f) #0 {
 entry:
-  call void @llvm.dbg.declare(metadata %struct.five* %f, metadata !17, metadata !{!"0x102"}), !dbg !18
+  call void @llvm.dbg.declare(metadata %struct.five* %f, metadata !17, metadata !{!"0x102\006"}), !dbg !18
   %a = getelementptr inbounds %struct.five* %f, i32 0, i32 0, !dbg !19
   %0 = load i32* %a, align 4, !dbg !19
   ret i32 %0, !dbg !19

 !14 = !{!"0xd\00d\006\0032\0032\0096\000", !1, !9, !8} ; [ DW_TAG_member ] [d] [line 6, size 32, align 32, offset 96] [from int]
 !15 = !{!"0xd\00e\007\0032\0032\00128\000", !1, !9, !8} ; [ DW_TAG_member ] [e] [line 7, size 32, align 32, offset 128] [from int]
 !16 = !{i32 2, !"Dwarf Version", i32 2}
-!17 = !{!"0x101\00f\0016777229\008192", !4, !5, !9} ; [ DW_TAG_arg_variable ] [f] [line 13]
+!17 = !{!"0x101\00f\0016777229\000", !4, !5, !9} ; [ DW_TAG_arg_variable ] [f] [line 13]
 !18 = !MDLocation(line: 13, scope: !4)
 !19 = !MDLocation(line: 16, scope: !4)
 !20 = !{i32 1, !"Debug Info Version", i32 2}

test/DebugInfo/ARM/lowerbdgdeclare_vla.ll

   %conv = fptosi float %r to i32, !dbg !23
   tail call void @llvm.dbg.declare(metadata i32 %conv, metadata !12, metadata !{!"0x102"}), !dbg !23
   %vla = alloca float, i32 %conv, align 4, !dbg !24
-  tail call void @llvm.dbg.declare(metadata float* %vla, metadata !14, metadata !{!"0x102"}), !dbg !24
+  tail call void @llvm.dbg.declare(metadata float* %vla, metadata !14, metadata !{!"0x102\006"}), !dbg !24
 ; The VLA alloca should be described by a dbg.declare:
 ; CHECK: call void @llvm.dbg.declare(metadata float* %vla, metadata ![[VLA:.*]], metadata {{.*}})
 ; The VLA alloca and following store into the array should not be lowered to like this:

 !11 = !{!"0x101\00r\0016777217\000", !4, !6, !9} ; [ DW_TAG_arg_variable ] [r] [line 1]
 !12 = !{!"0x100\00count\003\000", !4, !6, !13} ; [ DW_TAG_auto_variable ] [count] [line 3]
 !13 = !{!"0x24\00int\000\0032\0032\000\000\005", null, null} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
-!14 = !{!"0x100\00vla\004\008192", !4, !6, !15} ; [ DW_TAG_auto_variable ] [vla] [line 4]
+!14 = !{!"0x100\00vla\004\000", !4, !6, !15} ; [ DW_TAG_auto_variable ] [vla] [line 4]
 !15 = !{!"0x1\00\000\000\0032\000\000", null, null, !9, !16, i32 0, null, null, null} ; [ DW_TAG_array_type ] [line 0, size 0, align 32, offset 0] [from float]
 !16 = !{!17}
 !17 = !{!"0x21\000\00-1"}       ; [ DW_TAG_subrange_type ] [unbounded]

test/DebugInfo/ARM/selectiondag-deadcode.ll

   ; and SelectionDAGISel crashes.  It should definitely not
   ; crash. Drop the dbg_value instead.
   ; CHECK-NOT: "matrix"
-  tail call void @llvm.dbg.declare(metadata %class.Matrix3.0.6.10* %agg.result, metadata !45, metadata !{!"0x102"})
+  tail call void @llvm.dbg.declare(metadata %class.Matrix3.0.6.10* %agg.result, metadata !45, metadata !{!"0x102\006"})
   %2 = getelementptr inbounds %class.Matrix3.0.6.10* %agg.result, i32 0, i32 0, i32 8
   ret void
 }

 !39 = !{!"0x2e\00GetMatrix\00GetMatrix\00_Z9GetMatrixv\0032\000\001\000\006\00256\001\0032", !5, !40, !41, null, void (%class.Matrix3.0.6.10*)* @_Z9GetMatrixv, null, null, null} ; [ DW_TAG_subprogram ] [line 32] [def] [GetMatrix]
 !40 = !{!"0x29", !5}         ; [ DW_TAG_file_type ] [/Volumes/Data/radar/15094721/test.ii]
 !41 = !{!"0x15\00\000\000\000\000\000\000", i32 0, null, null, null, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
-!45 = !{!"0x100\00matrix\0035\008192", !39, !40, !4} ; [ DW_TAG_auto_variable ] [matrix] [line 35]
+!45 = !{!"0x100\00matrix\0035\000", !39, !40, !4} ; [ DW_TAG_auto_variable ] [matrix] [line 35]

test/DebugInfo/X86/dbg_value_direct.ll

 
 ; <label>:28                                      ; preds = %22, %entry
   store i32 %0, i32* %3, align 4
-  call void @llvm.dbg.declare(metadata %struct.A* %agg.result, metadata !24, metadata !{!"0x102"}), !dbg !25
+  call void @llvm.dbg.declare(metadata %struct.A* %agg.result, metadata !24, metadata !{!"0x102\006"}), !dbg !25
   call void @_ZN1AC1Ev(%struct.A* %agg.result), !dbg !25
   store i64 1172321806, i64* %4, !dbg !26
   %29 = inttoptr i64 %10 to i32*, !dbg !26

 !21 = !{!"0x24\00int\000\0032\0032\000\000\005", null, null} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
 !22 = !{i32 2, !"Dwarf Version", i32 3}
 !23 = !{!"0x101\00\0016777222\000", !4, !5, !21} ; [ DW_TAG_arg_variable ] [line 6]
-!24 = !{!"0x100\00a\007\008192", !4, !5, !8} ; [ DW_TAG_auto_variable ] [a] [line 7]
+!24 = !{!"0x100\00a\007\000", !4, !5, !8} ; [ DW_TAG_auto_variable ] [a] [line 7]
 !25 = !MDLocation(line: 7, scope: !4)
 !26 = !MDLocation(line: 8, scope: !4)
 !27 = !{i32 1, !"Debug Info Version", i32 2}

test/DebugInfo/X86/debug-loc-offset.ll

 define void @_Z3baz1A(%struct.A* %a) #2 {
 entry:
   %z = alloca i32, align 4
-  call void @llvm.dbg.declare(metadata %struct.A* %a, metadata !24, metadata !{!"0x102"}), !dbg !25
+  call void @llvm.dbg.declare(metadata %struct.A* %a, metadata !24, metadata !{!"0x102\006"}), !dbg !25
   call void @llvm.dbg.declare(metadata i32* %z, metadata !26, metadata !{!"0x102"}), !dbg !27
   store i32 2, i32* %z, align 4, !dbg !27
   %var = getelementptr inbounds %struct.A* %a, i32 0, i32 1, !dbg !28

 !21 = !{!"0x101\00b\0016777217\000", !4, !5, !8} ; [ DW_TAG_arg_variable ] [b] [line 1]
 !22 = !MDLocation(line: 1, scope: !4)
 !23 = !MDLocation(line: 2, scope: !4)
-!24 = !{!"0x101\00a\0016777222\008192", !14, !15, !"_ZTS1A"} ; [ DW_TAG_arg_variable ] [a] [line 6]
+!24 = !{!"0x101\00a\0016777222\000", !14, !15, !"_ZTS1A"} ; [ DW_TAG_arg_variable ] [a] [line 6]
 !25 = !MDLocation(line: 6, scope: !14)
 !26 = !{!"0x100\00z\007\000", !14, !15, !8} ; [ DW_TAG_auto_variable ] [z] [line 7]
 !27 = !MDLocation(line: 7, scope: !14)

test/DebugInfo/X86/op_deref.ll

 !11 = !MDLocation(line: 1, column: 26, scope: !5)
 !12 = !MDLocation(line: 3, column: 13, scope: !13)
 !13 = !{!"0xb\002\001\000", !28, !5} ; [ DW_TAG_lexical_block ]
-!14 = !{!"0x100\00vla\003\008192", !13, !6, !15} ; [ DW_TAG_auto_variable ]
+!14 = !{!"0x100\00vla\003\000", !13, !6, !15} ; [ DW_TAG_auto_variable ]
 !15 = !{!"0x1\00\000\000\0032\000\000", null, null, !9, !16, i32 0, null, null, null} ; [ DW_TAG_array_type ] [line 0, size 0, align 32, offset 0] [from int]
 !16 = !{!17}
 !17 = !{!"0x21\000\00-1"}        ; [ DW_TAG_subrange_type ]

 !27 = !MDLocation(line: 8, column: 1, scope: !13)
 !28 = !{!"bar.c", !"/Users/echristo/tmp"}
 !29 = !{i32 1, !"Debug Info Version", i32 2}
-!30 = !{!"0x102\006"} ; [ DW_TAG_expression ] [DW_OP_deref]
+!30 = !{!"0x102\006\006"} ; [ DW_TAG_expression ] [DW_OP_deref]

test/DebugInfo/X86/parameters.ll

 ; Function Attrs: uwtable
 define void @_ZN7pr147634funcENS_3fooE(%"struct.pr14763::foo"* noalias sret %agg.result, %"struct.pr14763::foo"* %f) #0 {
 entry:
-  call void @llvm.dbg.declare(metadata %"struct.pr14763::foo"* %f, metadata !22, metadata !{!"0x102"}), !dbg !24
+  call void @llvm.dbg.declare(metadata %"struct.pr14763::foo"* %f, metadata !22, metadata !{!"0x102\006"}), !dbg !24
   call void @_ZN7pr147633fooC1ERKS0_(%"struct.pr14763::foo"* %agg.result, %"struct.pr14763::foo"* %f), !dbg !25
   ret void, !dbg !25
 }

   %frombool = zext i1 %b to i8
   store i8 %frombool, i8* %b.addr, align 1
   call void @llvm.dbg.declare(metadata i8* %b.addr, metadata !26, metadata !{!"0x102"}), !dbg !27
-  call void @llvm.dbg.declare(metadata %"struct.pr14763::foo"* %g, metadata !28, metadata !{!"0x102"}), !dbg !27
+  call void @llvm.dbg.declare(metadata %"struct.pr14763::foo"* %g, metadata !28, metadata !{!"0x102\006"}), !dbg !27
   %0 = load i8* %b.addr, align 1, !dbg !29
   %tobool = trunc i8 %0 to i1, !dbg !29
   br i1 %tobool, label %if.then, label %if.end, !dbg !29

 !19 = !{null, !20, !8}
 !20 = !{!"0x24\00bool\000\008\008\000\000\002", null, null} ; [ DW_TAG_base_type ] [bool] [line 0, size 8, align 8, offset 0, enc DW_ATE_boolean]
 !21 = !{i32 2, !"Dwarf Version", i32 3}
-!22 = !{!"0x101\00f\0016777222\008192", !4, !23, !8} ; [ DW_TAG_arg_variable ] [f] [line 6]
+!22 = !{!"0x101\00f\0016777222\000", !4, !23, !8} ; [ DW_TAG_arg_variable ] [f] [line 6]
 !23 = !{!"0x29", !1}         ; [ DW_TAG_file_type ] [/tmp/pass.cpp]
 !24 = !MDLocation(line: 6, scope: !4)
 !25 = !MDLocation(line: 7, scope: !4)
 !26 = !{!"0x101\00b\0016777228\000", !17, !23, !20} ; [ DW_TAG_arg_variable ] [b] [line 12]
 !27 = !MDLocation(line: 12, scope: !17)
-!28 = !{!"0x101\00g\0033554444\008192", !17, !23, !8} ; [ DW_TAG_arg_variable ] [g] [line 12]
+!28 = !{!"0x101\00g\0033554444\000", !17, !23, !8} ; [ DW_TAG_arg_variable ] [g] [line 12]
 !29 = !MDLocation(line: 13, scope: !30)
 !30 = !{!"0xb\0013\000\000", !1, !17} ; [ DW_TAG_lexical_block ] [/tmp/pass.cpp]
 !31 = !MDLocation(line: 14, scope: !30)

test/DebugInfo/X86/pr19307.ll

   call void @llvm.dbg.declare(metadata i64** %offset.addr, metadata !45, metadata !{!"0x102"}), !dbg !46
   store i64* %limit, i64** %limit.addr, align 8
   call void @llvm.dbg.declare(metadata i64** %limit.addr, metadata !47, metadata !{!"0x102"}), !dbg !46
-  call void @llvm.dbg.declare(metadata %"class.std::basic_string"* %range, metadata !48, metadata !{!"0x102"}), !dbg !49
+  call void @llvm.dbg.declare(metadata %"class.std::basic_string"* %range, metadata !48, metadata !{!"0x102\006"}), !dbg !49
   %call = call i32 @_ZNKSs7compareEmmPKc(%"class.std::basic_string"* %range, i64 0, i64 6, i8* getelementptr inbounds ([7 x i8]* @.str, i32 0, i32 0)), !dbg !50
   %cmp = icmp ne i32 %call, 0, !dbg !50
   br i1 %cmp, label %if.then, label %lor.lhs.false, !dbg !50

 !45 = !{!"0x101\00offset\0016777219\000", !13, !14, !17} ; [ DW_TAG_arg_variable ] [offset] [line 3]
 !46 = !MDLocation(line: 3, scope: !13)
 !47 = !{!"0x101\00limit\0033554435\000", !13, !14, !17} ; [ DW_TAG_arg_variable ] [limit] [line 3]
-!48 = !{!"0x101\00range\0050331652\008192", !13, !14, !19} ; [ DW_TAG_arg_variable ] [range] [line 4]
+!48 = !{!"0x101\00range\0050331652\000", !13, !14, !19} ; [ DW_TAG_arg_variable ] [range] [line 4]
 !49 = !MDLocation(line: 4, scope: !13)
 !50 = !MDLocation(line: 5, scope: !51)
 !51 = !{!"0xb\005\000\000", !1, !13} ; [ DW_TAG_lexical_block ] [/llvm_cmake_gcc/pr19307.cc]

test/DebugInfo/X86/reference-argument.ll

   %this.addr = alloca %class.A*, align 8
   store %class.A* %this, %class.A** %this.addr, align 8
   call void @llvm.dbg.declare(metadata %class.A** %this.addr, metadata !59, metadata !{!"0x102"}), !dbg !61
-  call void @llvm.dbg.declare(metadata %class.SVal* %v, metadata !62, metadata !{!"0x102"}), !dbg !61
+  call void @llvm.dbg.declare(metadata %class.SVal* %v, metadata !62, metadata !{!"0x102\006"}), !dbg !61
   %this1 = load %class.A** %this.addr
   call void @_Z3barR4SVal(%class.SVal* %v), !dbg !61
   ret void, !dbg !61

 !59 = !{!"0x101\00this\0016777238\001088", !35, !5, !60} ; [ DW_TAG_arg_variable ] [this] [line 22]
 !60 = !{!"0xf\00\000\0064\0064\000\000", null, null, !39} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [from A]
 !61 = !MDLocation(line: 22, scope: !35)
-!62 = !{!"0x101\00v\0033554454\008192", !35, !5, !9} ; [ DW_TAG_arg_variable ] [v] [line 22]
+!62 = !{!"0x101\00v\0033554454\000", !35, !5, !9} ; [ DW_TAG_arg_variable ] [v] [line 22]
 !63 = !{!"0x101\00this\0016777230\001088", !33, !5, !64} ; [ DW_TAG_arg_variable ] [this] [line 14]
 !64 = !{!"0xf\00\000\0064\0064\000\000", null, null, !9} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [from SVal]
 !65 = !MDLocation(line: 14, scope: !33)

test/DebugInfo/X86/sret.ll

   call void @llvm.dbg.declare(metadata %class.B** %this.addr, metadata !89, metadata !{!"0x102"}), !dbg !91
   %this1 = load %class.B** %this.addr
   store i1 false, i1* %nrvo, !dbg !92
-  call void @llvm.dbg.declare(metadata %class.A* %agg.result, metadata !93, metadata !{!"0x102"}), !dbg !92
+  call void @llvm.dbg.declare(metadata %class.A* %agg.result, metadata !93, metadata !{!"0x102\006"}), !dbg !92
   call void @_ZN1AC1Ei(%class.A* %agg.result, i32 12), !dbg !92
   store i1 true, i1* %nrvo, !dbg !94
   store i32 1, i32* %cleanup.dest.slot

 !90 = !{!"0xf\00\000\0064\0064\000\000", null, null, !"_ZTS1B"} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [from _ZTS1B]
 !91 = !MDLocation(line: 0, scope: !53)
 !92 = !MDLocation(line: 49, scope: !53)
-!93 = !{!"0x100\00a\0049\008192", !53, !7, !4} ; [ DW_TAG_auto_variable ] [a] [line 49]
+!93 = !{!"0x100\00a\0049\000", !53, !7, !4} ; [ DW_TAG_auto_variable ] [a] [line 49]
 !94 = !MDLocation(line: 50, scope: !53)
 !95 = !MDLocation(line: 51, scope: !53)
 !96 = !MDLocation(line: 51, scope: !97)

test/DebugInfo/X86/vla.ll

   %2 = call i8* @llvm.stacksave(), !dbg !17
   store i8* %2, i8** %saved_stack, !dbg !17
   %vla = alloca i32, i64 %1, align 16, !dbg !17
-  call void @llvm.dbg.declare(metadata i32* %vla, metadata !18, metadata !{!"0x102"}), !dbg !17
+  call void @llvm.dbg.declare(metadata i32* %vla, metadata !18, metadata !{!"0x102\006"}), !dbg !17
   %arrayidx = getelementptr inbounds i32* %vla, i64 0, !dbg !22
   store i32 42, i32* %arrayidx, align 4, !dbg !22
   %3 = load i32* %n.addr, align 4, !dbg !23

 !15 = !{!"0x101\00n\0016777217\000", !4, !5, !8} ; [ DW_TAG_arg_variable ] [n] [line 1]
 !16 = !MDLocation(line: 1, scope: !4)
 !17 = !MDLocation(line: 2, scope: !4)
-!18 = !{!"0x100\00a\002\008192", !4, !5, !19} ; [ DW_TAG_auto_variable ] [a] [line 2]
+!18 = !{!"0x100\00a\002\000", !4, !5, !19} ; [ DW_TAG_auto_variable ] [a] [line 2]
 !19 = !{!"0x1\00\000\000\0032\000\000", null, null, !8, !20, i32 0, null, null, null} ; [ DW_TAG_array_type ] [line 0, size 0, align 32, offset 0] [from int]
 !20 = !{!21}
 !21 = !{!"0x21\000\00-1"}       ; [ DW_TAG_subrange_type ] [unbounded]

test/DebugInfo/debug-info-qualifiers.ll

 !4 = !{!"0x2\00A\002\008\008\000\000\000", !5, null, null, !6, null, null, !"_ZTS1A"} ; [ DW_TAG_class_type ] [A] [line 2, size 8, align 8, offset 0] [def] [from ]
 !5 = !{!"debug-info-qualifiers.cpp", !""}
 !6 = !{!7, !13}
-!7 = !{!"0x2e\00l\00l\00_ZNKR1A1lEv\005\000\000\000\006\0016640\000\005", !5, !"_ZTS1A", !8, null, null, null, i32 0, !12} ; [ DW_TAG_subprogram ] [line 5] [reference] [l]
-!8 = !{!"0x15\00\000\000\000\000\0016384\000", i32 0, null, null, !9, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [reference] [from ]
+!7 = !{!"0x2e\00l\00l\00_ZNKR1A1lEv\005\000\000\000\006\008448\000\005", !5, !"_ZTS1A", !8, null, null, null, i32 0, !12} ; [ DW_TAG_subprogram ] [line 5] [reference] [l]
+!8 = !{!"0x15\00\000\000\000\000\008192\000", i32 0, null, null, !9, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [reference] [from ]
 !9 = !{null, !10}
 !10 = !{!"0xf\00\000\0064\0064\000\001088", null, null, !11} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [artificial] [from ]
 !11 = !{!"0x26\00\000\000\000\000\000", null, null, !"_ZTS1A"} ; [ DW_TAG_const_type ] [line 0, size 0, align 0, offset 0] [from _ZTS1A]
 !12 = !{i32 786468}
-!13 = !{!"0x2e\00r\00r\00_ZNKO1A1rEv\007\000\000\000\006\0033024\000\007", !5, !"_ZTS1A", !14, null, null, null, i32 0, !15} ; [ DW_TAG_subprogram ] [line 7] [rvalue reference] [r]
-!14 = !{!"0x15\00\000\000\000\000\0032768\000", i32 0, null, null, !9, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [rvalue reference] [from ]
+!13 = !{!"0x2e\00r\00r\00_ZNKO1A1rEv\007\000\000\000\006\0017408\000\007", !5, !"_ZTS1A", !14, null, null, null, i32 0, !15} ; [ DW_TAG_subprogram ] [line 7] [rvalue reference] [r]
+!14 = !{!"0x15\00\000\000\000\000\0016384\000", i32 0, null, null, !9, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [rvalue reference] [from ]
 !15 = !{i32 786468}
 !16 = !{!17}
 !17 = !{!"0x2e\00g\00g\00_Z1gv\0010\000\001\000\006\00256\000\0010", !5, !18, !19, null, void ()* @_Z1gv, null, null, !2} ; [ DW_TAG_subprogram ] [line 10] [def] [g]

 !25 = !MDLocation(line: 11, scope: !17)
 !26 = !{!"0x100\00pl\0016\000", !17, !18, !27} ; [ DW_TAG_auto_variable ] [pl] [line 16]
 !27 = !{!"0x1f\00\000\000\000\000\000", null, null, !28, !"_ZTS1A"} ; [ DW_TAG_ptr_to_member_type ] [line 0, size 0, align 0, offset 0] [from ]
-!28 = !{!"0x15\00\000\000\000\000\0016384\000", i32 0, null, null, !29, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [reference] [from ]
+!28 = !{!"0x15\00\000\000\000\000\008192\000", i32 0, null, null, !29, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [reference] [from ]
 !29 = !{null, !30}
 !30 = !{!"0xf\00\000\0064\0064\000\001088", null, null, !"_ZTS1A"} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [artificial] [from _ZTS1A]
 !31 = !MDLocation(line: 16, scope: !17)
 !32 = !{!"0x100\00pr\0021\000", !17, !18, !33} ; [ DW_TAG_auto_variable ] [pr] [line 21]
 !33 = !{!"0x1f\00\000\000\000\000\000", null, null, !34, !"_ZTS1A"} ; [ DW_TAG_ptr_to_member_type ] [line 0, size 0, align 0, offset 0] [from ]
-!34 = !{!"0x15\00\000\000\000\000\0032768\000", i32 0, null, null, !29, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [rvalue reference] [from ]
+!34 = !{!"0x15\00\000\000\000\000\0016384\000", i32 0, null, null, !29, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [rvalue reference] [from ]
 !35 = !MDLocation(line: 21, scope: !17)
 !36 = !MDLocation(line: 22, scope: !17)