Index: llvm/trunk/lib/CodeGen/AsmPrinter/DbgEntityHistoryCalculator.cpp
===================================================================
--- llvm/trunk/lib/CodeGen/AsmPrinter/DbgEntityHistoryCalculator.cpp
+++ llvm/trunk/lib/CodeGen/AsmPrinter/DbgEntityHistoryCalculator.cpp
@@ -352,17 +352,43 @@
       }
     }
 
-    // Make sure locations for register-described variables are valid only
-    // until the end of the basic block (unless it's the last basic block, in
-    // which case let their liveness run off to the end of the function).
+    // Make sure locations for all variables are valid only until the end of
+    // the basic block (unless it's the last basic block, in which case let
+    // their liveness run off to the end of the function).
     if (!MBB.empty() && &MBB != &MF->back()) {
-      for (auto I = RegVars.begin(), E = RegVars.end(); I != E;) {
-        auto CurElem = I++; // CurElem can be erased below.
-        if (TRI->isVirtualRegister(CurElem->first) ||
-            ChangingRegs.test(CurElem->first))
-          clobberRegisterUses(RegVars, CurElem, DbgValues, LiveEntries,
-                              MBB.back());
+      // Iterate over all variables that have open debug values.
+      SmallSet<unsigned, 8> RegsToClobber;
+      for (auto &Pair : LiveEntries) {
+        // Iterate over history entries for all open fragments.
+        SmallVector<EntryIndex, 8> IdxesToRemove;
+        for (EntryIndex Idx : Pair.second) {
+          DbgValueHistoryMap::Entry &Ent = DbgValues.getEntry(Pair.first, Idx);
+          assert(Ent.isDbgValue() && !Ent.isClosed());
+          const MachineInstr *DbgValue = Ent.getInstr();
+
+          // If this is a register or indirect DBG_VALUE, apply some futher
+          // tests to see if we should clobber it. Perform the clobbering
+          // later though, to keep LiveEntries iteration stable.
+          if (DbgValue->getOperand(0).isReg()) {
+            unsigned RegNo = DbgValue->getOperand(0).getReg();
+            if (TRI->isVirtualRegister(RegNo) || ChangingRegs.test(RegNo))
+              RegsToClobber.insert(RegNo);
+          } else {
+            // This is a constant, terminate it at end of the block. Store
+            // eliminated EntryIdx and delete later, for iteration stability.
+            EntryIndex ClobIdx = DbgValues.startClobber(Pair.first, MBB.back());
+            DbgValues.getEntry(Pair.first, Idx).endEntry(ClobIdx);
+            IdxesToRemove.push_back(Idx);
+          }
+        }
+
+        for (EntryIndex Idx : IdxesToRemove)
+          Pair.second.erase(Idx);
       }
+
+      // Implement clobbering of registers at the end of BB.
+      for (unsigned Reg : RegsToClobber)
+        clobberRegisterUses(RegVars, Reg, DbgValues, LiveEntries, MBB.back());
     }
   }
 }
Index: llvm/trunk/lib/CodeGen/LiveDebugValues.cpp
===================================================================
--- llvm/trunk/lib/CodeGen/LiveDebugValues.cpp
+++ llvm/trunk/lib/CodeGen/LiveDebugValues.cpp
@@ -143,7 +143,8 @@
     enum VarLocKind {
       InvalidKind = 0,
       RegisterKind,
-      SpillLocKind
+      SpillLocKind,
+      ImmediateKind
     } Kind = InvalidKind;
 
     /// The value location. Stored separately to avoid repeatedly
@@ -152,6 +153,9 @@
       uint64_t RegNo;
       SpillLoc SpillLocation;
       uint64_t Hash;
+      int64_t Immediate;
+      const ConstantFP *FPImm;
+      const ConstantInt *CImm;
     } Loc;
 
     VarLoc(const MachineInstr &MI, LexicalScopes &LS)
@@ -164,6 +168,15 @@
       if (int RegNo = isDbgValueDescribedByReg(MI)) {
         Kind = RegisterKind;
         Loc.RegNo = RegNo;
+      } else if (MI.getOperand(0).isImm()) {
+        Kind = ImmediateKind;
+        Loc.Immediate = MI.getOperand(0).getImm();
+      } else if (MI.getOperand(0).isFPImm()) {
+        Kind = ImmediateKind;
+        Loc.FPImm = MI.getOperand(0).getFPImm();
+      } else if (MI.getOperand(0).isCImm()) {
+        Kind = ImmediateKind;
+        Loc.CImm = MI.getOperand(0).getCImm();
       }
     }
 
@@ -178,6 +191,9 @@
       Loc.SpillLocation = {SpillBase, SpillOffset};
     }
 
+    // Is the Loc field a constant or constant object?
+    bool isConstant() const { return Kind == ImmediateKind; }
+
     /// If this variable is described by a register, return it,
     /// otherwise return 0.
     unsigned isDescribedByReg() const {
@@ -195,7 +211,8 @@
 #endif
 
     bool operator==(const VarLoc &Other) const {
-      return Var == Other.Var && Loc.Hash == Other.Loc.Hash;
+      return Kind == Other.Kind && Var == Other.Var &&
+             Loc.Hash == Other.Loc.Hash;
     }
 
     /// This operator guarantees that VarLocs are sorted by Variable first.
@@ -408,11 +425,23 @@
   OpenRanges.erase(V);
 
   // Add the VarLoc to OpenRanges from this DBG_VALUE.
-  // TODO: Currently handles DBG_VALUE which has only reg as location.
-  if (isDbgValueDescribedByReg(MI)) {
+  unsigned ID;
+  if (isDbgValueDescribedByReg(MI) || MI.getOperand(0).isImm() ||
+      MI.getOperand(0).isFPImm() || MI.getOperand(0).isCImm()) {
+    // Use normal VarLoc constructor for registers and immediates.
     VarLoc VL(MI, LS);
-    unsigned ID = VarLocIDs.insert(VL);
+    ID = VarLocIDs.insert(VL);
+    OpenRanges.insert(ID, VL.Var);
+  } else if (MI.hasOneMemOperand()) {
+    // It's a stack spill -- fetch spill base and offset.
+    VarLoc::SpillLoc SpillLocation = extractSpillBaseRegAndOffset(MI);
+    VarLoc VL(MI, SpillLocation.SpillBase, SpillLocation.SpillOffset, LS);
+    ID = VarLocIDs.insert(VL);
     OpenRanges.insert(ID, VL.Var);
+  } else {
+    // This must be an undefined location. We should leave OpenRanges closed.
+    assert(MI.getOperand(0).isReg() && MI.getOperand(0).getReg() == 0 &&
+           "Unexpected non-undef DBG_VALUE encountered");
   }
 }
 
@@ -806,12 +835,19 @@
     // a new DBG_VALUE. process() will end this range however appropriate.
     const VarLoc &DiffIt = VarLocIDs[ID];
     const MachineInstr *DMI = &DiffIt.MI;
-    MachineInstr *MI =
-        BuildMI(MBB, MBB.instr_begin(), DMI->getDebugLoc(), DMI->getDesc(),
-                DMI->isIndirectDebugValue(), DMI->getOperand(0).getReg(),
-                DMI->getDebugVariable(), DMI->getDebugExpression());
-    if (DMI->isIndirectDebugValue())
-      MI->getOperand(1).setImm(DMI->getOperand(1).getImm());
+    MachineInstr *MI = nullptr;
+    if (DiffIt.isConstant()) {
+      MachineOperand MO(DMI->getOperand(0));
+      MI = BuildMI(MBB, MBB.instr_begin(), DMI->getDebugLoc(), DMI->getDesc(),
+                   false, MO, DMI->getDebugVariable(),
+                   DMI->getDebugExpression());
+    } else {
+      MI = BuildMI(MBB, MBB.instr_begin(), DMI->getDebugLoc(), DMI->getDesc(),
+                   DMI->isIndirectDebugValue(), DMI->getOperand(0).getReg(),
+                   DMI->getDebugVariable(), DMI->getDebugExpression());
+      if (DMI->isIndirectDebugValue())
+        MI->getOperand(1).setImm(DMI->getOperand(1).getImm());
+    }
     LLVM_DEBUG(dbgs() << "Inserted: "; MI->dump(););
     ILS.set(ID);
     ++NumInserted;
Index: llvm/trunk/test/DebugInfo/COFF/pieces.ll
===================================================================
--- llvm/trunk/test/DebugInfo/COFF/pieces.ll
+++ llvm/trunk/test/DebugInfo/COFF/pieces.ll
@@ -40,9 +40,10 @@
 ; ASM: # %bb.2:                                 # %for.body.preheader
 ; ASM:         xorl    %edi, %edi
 ; ASM:         xorl    %esi, %esi
+; ASM: [[oy_ox_start:\.Ltmp[0-9]+]]:
 ; ASM:         .p2align        4, 0x90
 ; ASM: .LBB0_3:                                # %for.body
-; ASM: [[oy_ox_start:\.Ltmp[0-9]+]]:
+; ASM:        #DEBUG_VALUE: loop_csr:o <- [DW_OP_LLVM_fragment 0 32] 0
 ; ASM:        #DEBUG_VALUE: loop_csr:o <- [DW_OP_LLVM_fragment 0 32] $edi
 ; ASM:        #DEBUG_VALUE: loop_csr:o <- [DW_OP_LLVM_fragment 32 32] $esi
 ; ASM:        .cv_loc 0 1 13 11               # t.c:13:11
@@ -59,13 +60,21 @@
 ; ASM:         #DEBUG_VALUE: loop_csr:o <- [DW_OP_LLVM_fragment 32 32] $esi
 ; ASM:         cmpl    n(%rip), %eax
 ; ASM:         jl      .LBB0_3
+; ASM: [[loopskip_start:\.Ltmp[0-9]+]]:
+; ASM:         #DEBUG_VALUE: loop_csr:o <- [DW_OP_LLVM_fragment 0 32] 0
+; ASM:         xorl    %esi, %esi
+; ASM:         xorl    %edi, %edi
 ; ASM: [[oy_end:\.Ltmp[0-9]+]]:
 ; ASM:         addl    %edi, %esi
 ; ASM:         movl    %esi, %eax
 
+; XXX FIXME: the debug value line after loopskip_start should be repeated
+; because both fields of 'o' are zero flowing into this block. However, it
+; appears livedebugvalues doesn't account for fragments.
 
 ; ASM-LABEL: pad_right: # @pad_right
 ; ASM:         movq    %rcx, %rax
+; ASM: [[pad_right_tmp:\.Ltmp[0-9]+]]:
 ; ASM:         #DEBUG_VALUE: pad_right:o <- [DW_OP_LLVM_fragment 32 32] $eax
 ; ASM:         retq
 
@@ -73,6 +82,7 @@
 ; ASM-LABEL: pad_left: # @pad_left
 ; ASM:         .cv_loc 2 1 24 3                # t.c:24:3
 ; ASM:         movq    %rcx, %rax
+; ASM: [[pad_left_tmp:\.Ltmp[0-9]+]]:
 ; ASM:         #DEBUG_VALUE: pad_left:o <- [DW_OP_LLVM_fragment 0 32] $eax
 ; ASM:         retq
 
@@ -104,8 +114,8 @@
 ; ASM:        .asciz  "o"
 ; ASM:        .cv_def_range    [[oy_ox_start]] [[ox_start]], "C\021\030\000\000\000\000\000\000\000"
 ; ASM:        .cv_def_range    [[oy_ox_start]] [[oy_start]], "C\021\027\000\000\000\004\000\000\000"
-; ASM:        .cv_def_range    [[ox_start]] [[oy_end]], "C\021\030\000\000\000\000\000\000\000"
-; ASM:        .cv_def_range    [[oy_start]] [[oy_end]], "C\021\027\000\000\000\004\000\000\000"
+; ASM:        .cv_def_range    [[ox_start]] [[loopskip_start]], "C\021\030\000\000\000\000\000\000\000"
+; ASM:        .cv_def_range    [[oy_start]] [[loopskip_start]], "C\021\027\000\000\000\004\000\000\000"
 
 
 ; OBJ-LABEL: GlobalProcIdSym {
@@ -136,7 +146,7 @@
 ; ASM:        .asciz  "pad_right"             # Function name
 ; ASM:        .short  4414                    # Record kind: S_LOCAL
 ; ASM:        .asciz  "o"
-; ASM:        .cv_def_range    .Ltmp8 .Ltmp8, "C\021\021\000\000\000\004\000\000\000"
+; ASM:        .cv_def_range    [[pad_right_tmp]] [[pad_right_tmp]], "C\021\021\000\000\000\004\000\000\000"
 
 ; OBJ-LABEL: GlobalProcIdSym {
 ; OBJ:         Kind: S_GPROC32_ID (0x1147)
@@ -159,7 +169,7 @@
 ; ASM:        .asciz  "pad_left"              # Function name
 ; ASM:        .short  4414                    # Record kind: S_LOCAL
 ; ASM:        .asciz  "o"
-; ASM:        .cv_def_range    .Ltmp10 .Ltmp10, "C\021\021\000\000\000\000\000\000\000"
+; ASM:        .cv_def_range    [[pad_left_tmp]] [[pad_left_tmp]], "C\021\021\000\000\000\000\000\000\000"
 
 ; OBJ-LABEL: GlobalProcIdSym {
 ; OBJ:         Kind: S_GPROC32_ID (0x1147)
Index: llvm/trunk/test/DebugInfo/MIR/AArch64/implicit-def-dead-scope.mir
===================================================================
--- llvm/trunk/test/DebugInfo/MIR/AArch64/implicit-def-dead-scope.mir
+++ llvm/trunk/test/DebugInfo/MIR/AArch64/implicit-def-dead-scope.mir
@@ -5,8 +5,10 @@
 #  encountering an IMPLICIT_DEF in its own lexical scope.
 
 # CHECK: .debug_info contents:
-# CHECK: DW_TAG_formal_parameter
-# CHECK:   DW_AT_const_value [DW_FORM_udata]   (0)
+# CHECK:       DW_TAG_formal_parameter
+# CHECK:       DW_AT_location [DW_FORM_sec_offset]
+# CHECK-NEXT:                 DW_OP_lit0, DW_OP_stack_value
+# CHECK-NEXT:  DW_AT_abstract_origin {{.*}} "name"
 --- |
   ; ModuleID = 't.ll'
   source_filename = "t.ll"
@@ -103,7 +105,7 @@
   !15 = distinct !DICompositeType(tag: DW_TAG_class_type, name: "v", file: !5, line: 97, size: 64, elements: !2, identifier: "_ZTS1v")
   !16 = !DISubroutineType(types: !2)
   !17 = !DISubprogram(name: "bv", linkageName: "_ZN1v2bvEv", scope: !15, file: !5, line: 98, type: !16, isLocal: false, isDefinition: false, scopeLine: 98, flags: DIFlagPrototyped, isOptimized: true)
-  !18 = !DILocalVariable(arg: 2, scope: !19, file: !5, line: 22, type: !21)
+  !18 = !DILocalVariable(name: "name", arg: 2, scope: !19, file: !5, line: 22, type: !21)
   !19 = distinct !DISubprogram(name: "m", linkageName: "_ZN1jILi6EN1a1fEE1mEj", scope: !11, file: !5, line: 22, type: !16, isLocal: false, isDefinition: true, scopeLine: 22, flags: DIFlagPrototyped, isOptimized: true, unit: !0, declaration: !20, retainedNodes: !2)
   !20 = !DISubprogram(name: "m", linkageName: "_ZN1jILi6EN1a1fEE1mEj", scope: !11, file: !5, line: 22, type: !16, isLocal: false, isDefinition: false, scopeLine: 22, flags: DIFlagPublic | DIFlagPrototyped, isOptimized: true)
   !21 = !DIDerivedType(tag: DW_TAG_typedef, name: "h", file: !5, line: 10, baseType: !22)
Index: llvm/trunk/test/DebugInfo/X86/fission-ranges.ll
===================================================================
--- llvm/trunk/test/DebugInfo/X86/fission-ranges.ll
+++ llvm/trunk/test/DebugInfo/X86/fission-ranges.ll
@@ -15,6 +15,7 @@
 ; CHECK-NEXT: DW_AT_GNU_addr_base [DW_FORM_sec_offset]                   (0x00000000)
 
 ; CHECK: .debug_info.dwo contents:
+; CHECK: DW_AT_location [DW_FORM_sec_offset]   ([[P:0x[0-9a-z]*]]
 ; CHECK: DW_AT_location [DW_FORM_sec_offset]   ([[A:0x[0-9a-z]*]]
 ; CHECK: DW_AT_location [DW_FORM_sec_offset]   ([[E:0x[0-9a-z]*]]
 ; CHECK: DW_AT_location [DW_FORM_sec_offset]   ([[B:0x[0-9a-z]*]]
@@ -27,24 +28,31 @@
 ; Don't assume these locations are entirely correct - feel free to update them
 ; if they've changed due to a bugfix, change in register allocation, etc.
 
+; CHECK:      [[P]]:
+; CHECK-NEXT:   Addr idx 1 (w/ length 204): DW_OP_consts +1, DW_OP_stack_value
 ; CHECK:      [[A]]:
 ; CHECK-NEXT:   Addr idx 2 (w/ length 169): DW_OP_consts +0, DW_OP_stack_value
-; CHECK-NEXT:   Addr idx 3 (w/ length 25): DW_OP_reg0 RAX
+; CHECK-NEXT:   Addr idx 3 (w/ length 15): DW_OP_reg0 RAX
+; CHECK-NEXT:   Addr idx 4 (w/ length 6): DW_OP_breg7 RSP-8
+; CHECK-NEXT:   Addr idx 5 (w/ length 4): DW_OP_reg0 RAX
 ; CHECK:      [[E]]:
-; CHECK-NEXT:   Addr idx 4 (w/ length 19): DW_OP_reg0 RAX
+; CHECK-NEXT:   Addr idx 6 (w/ length 9): DW_OP_reg0 RAX
+; CHECK-NEXT:   Addr idx 7 (w/ length 98): DW_OP_breg7 RSP-44
 ; CHECK:      [[B]]:
-; CHECK-NEXT:   Addr idx 5 (w/ length 17): DW_OP_reg0 RAX
+; CHECK-NEXT:   Addr idx 8 (w/ length 15): DW_OP_reg0 RAX
+; CHECK-NEXT:   Addr idx 9 (w/ length 66): DW_OP_breg7 RSP-32
 ; CHECK:      [[D]]:
-; CHECK-NEXT:   Addr idx 6 (w/ length 17): DW_OP_reg0 RAX
+; CHECK-NEXT:   Addr idx 10 (w/ length 15): DW_OP_reg0 RAX
+; CHECK-NEXT:   Addr idx 11 (w/ length 42): DW_OP_breg7 RSP-20
 
 ; Make sure we don't produce any relocations in any .dwo section (though in particular, debug_info.dwo)
 ; HDR-NOT: .rela.{{.*}}.dwo
 
 ; Make sure we have enough stuff in the debug_addr to cover the address indexes
-; (6 is the last index in debug_loc.dwo, making 7 entries of 8 bytes each, 7 * 8
-; == 56 base 10 == 38 base 16)
+; (11 is the last index in debug_loc.dwo, making 12 entries of 8 bytes each,
+; 12 * 8 == 96 base 10 == 60 base 16)
 
-; HDR: .debug_addr 00000038
+; HDR: .debug_addr 00000060
 ; HDR-NOT: .rela.{{.*}}.dwo
 
 ; Check for the existence of a DWARF v5-style range list table in the .debug_rnglists
Index: llvm/trunk/test/DebugInfo/X86/live-debug-values-constprop.mir
===================================================================
--- llvm/trunk/test/DebugInfo/X86/live-debug-values-constprop.mir
+++ llvm/trunk/test/DebugInfo/X86/live-debug-values-constprop.mir
@@ -0,0 +1,347 @@
+# RUN: llc %s -o - -run-pass=livedebugvalues -mtriple=x86_64-unknown-unknown | FileCheck %s --check-prefix=CHECK
+# RUN: llc %s -o - -start-before=livedebugvalues -filetype=obj -mtriple=x86_64-unknown-unknown | llvm-dwarfdump - | FileCheck %s --check-prefix=RANGES
+# Check that livedebugvalues does the right thing when register and constant
+# DBG_VALUEs interact, and that their ranges are correctly terminated by the
+# debug printing backend.
+--- |
+  ; All these IR functions are duds, see the MIR below.
+  source_filename = "<stdin>"
+  target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+  
+  define i32 @foo(i32* %bees, i32* %output) !dbg !4 {
+  entry:
+    br i1 undef, label %bb1, label %bb1
+  bb1:
+    br label %bb3
+  bb2:
+    br label %bb3
+  bb3:
+    ret i32 0
+  }
+
+  define i32 @bar(i32* %bees, i32* %output) !dbg !40 {
+  entry:
+    br i1 undef, label %bb1, label %bb1
+  bb1:
+    br label %bb3
+  bb2:
+    br label %bb3
+  bb3:
+    ret i32 0
+  }
+
+  define i32 @baz(i32* %bees, i32* %output) !dbg !80 {
+  entry:
+    br i1 undef, label %bb1, label %bb1
+  bb1:
+    br label %bb3
+  bb2:
+    br label %bb3
+  bb3:
+    ret i32 0
+  }
+
+  define i32 @qux(i32* %bees, i32* %output) !dbg !120 {
+  entry:
+    br i1 undef, label %bb1, label %bb1
+  bb1:
+    br label %bb3
+  bb2:
+    br label %bb3
+  bb3:
+    ret i32 0
+  }
+
+  ; Function Attrs: nounwind readnone speculatable
+  declare void @llvm.dbg.value(metadata, metadata, metadata)
+  
+  ; Function Attrs: nounwind readnone speculatable
+  declare void @llvm.dbg.declare(metadata, metadata, metadata)
+  
+  ; Function Attrs: nounwind
+  declare void @llvm.stackprotector(i8*, i8**)
+  
+  !llvm.module.flags = !{!0, !100}
+  !llvm.dbg.cu = !{!1}
+  
+  !100 = !{i32 2, !"Dwarf Version", i32 4}
+  !0 = !{i32 2, !"Debug Info Version", i32 3}
+  !1 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !2, producer: "beards", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug)
+  !2 = !DIFile(filename: "bees.cpp", directory: ".")
+  !3 = !DILocalVariable(name: "flannel", scope: !4, file: !2, line: 1, type: !16)
+  !4 = distinct !DISubprogram(name: "nope", scope: !2, file: !2, line: 1, spFlags: DISPFlagDefinition, unit: !1, retainedNodes: !13, type: !14, isDefinition: true)
+  !5 = !DILocation(line: 0, scope: !4)
+  !6 = !DILocation(line: 1, scope: !4)
+  !7 = !DILocation(line: 2, scope: !4)
+  !8 = !DILocation(line: 4, scope: !4)
+  !9 = !DILocation(line: 5, scope: !4)
+  !10 = !DILocation(line: 6, scope: !4)
+  !11 = !DILocation(line: 7, scope: !4)
+  !12 = !DILocation(line: 8, scope: !4)
+  !13 = !{!3}
+  !14 = !DISubroutineType(types: !15)
+  !15 = !{!16}
+  !16 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
+  !40 = distinct !DISubprogram(name: "bar", scope: !2, file: !2, line: 1, spFlags: DISPFlagDefinition, unit: !1, retainedNodes: !13, type: !14, isDefinition: true)
+  !41 = !DILocalVariable(name: "towel", scope: !40, file: !2, line: 1, type: !16)
+  !42 = !DILocation(line: 40, scope: !40)
+  !80 = distinct !DISubprogram(name: "baz", scope: !2, file: !2, line: 1, spFlags: DISPFlagDefinition, unit: !1, retainedNodes: !13, type: !14, isDefinition: true)
+  !81 = !DILocalVariable(name: "socks", scope: !80, file: !2, line: 1, type: !16)
+  !82 = !DILocation(line: 40, scope: !80)
+  !120 = distinct !DISubprogram(name: "qux", scope: !2, file: !2, line: 1, spFlags: DISPFlagDefinition, unit: !1, retainedNodes: !13, type: !14, isDefinition: true)
+  !121 = !DILocalVariable(name: "shoes", scope: !120, file: !2, line: 1, type: !16)
+  !122 = !DILocation(line: 40, scope: !120)
+
+...
+---
+name:            foo
+alignment:       4
+tracksRegLiveness: true
+registers:       []
+liveins:         
+  - { reg: '$rdi', virtual-reg: '' }
+body:             |
+
+  ; Two DBG_VALUEs for eax merge into bb3, check that livedebugvalues propagates
+  ; the location.
+  ; CHECK-LABEL: name: foo
+  ; CHECK-LABEL: bb.1.bb1
+  ; CHECK:       $eax = MOV32rr
+  ; CHECK-NEXT:  DBG_VALUE $eax
+  ; CHECK-NEXT:  JMP_1 %bb.3
+  ; CHECK-LABEL: bb.2.bb2
+  ; CHECK:       $eax = ADD32ri8
+  ; CHECK-NEXT:  DBG_VALUE $eax
+  ; CHECK-NEXT:  JMP_1 %bb.3
+  ; CHECK-LABEL: bb.3.bb3
+  ; CHECK:       DBG_VALUE $eax
+  ; Test for there being a location-list gap between bb1 and bb2, as the
+  ; variable does not have a location over the ADD32ri. The range should also
+  ; extend over the final bb.
+  ; RANGES-LABEL: DW_TAG_subprogram
+  ; RANGES:       DW_AT_high_pc (0x[[NOPEHIGHPC:[0-9a-f]+]])
+  ; RANGES-LABEL: DW_AT_name ("nope")
+  ; RANGES:       DW_AT_location (0x{{[0-9a-f]+}}
+  ; RANGES-NEXT:   [0x{{[0-9a-f]+}}, 0x[[NOPEADDR:[0-9a-f]+]]): DW_OP_reg0 RAX
+  ; RANGES-NEXT:   [
+  ; RANGES-NOT:    0x[[NOPEADDR]]
+  ; RANGES-SAME:   , 0x[[NOPEHIGHPC]]): DW_OP_reg0 RAX
+
+  bb.0.entry:
+    successors: %bb.1, %bb.2
+    liveins: $rdi
+  
+    $ecx = XOR32rr undef $ecx, undef $ecx, implicit-def $eflags
+    JCC_1 %bb.1, 2, implicit killed $eflags
+    JMP_1 %bb.2
+  
+  bb.1.bb1 (align 4):
+    successors: %bb.3
+    liveins: $ecx, $rdi
+  
+    $eax = MOV32rr killed $ecx, implicit-def $rax
+    DBG_VALUE $eax, $noreg, !3, !DIExpression(), debug-location !8
+    JMP_1 %bb.3
+  
+  bb.2.bb2:
+    successors: %bb.3
+    liveins: $rax
+  
+    $eax = ADD32ri8 $eax, 3, implicit-def dead $eflags, implicit killed $rax, implicit-def $rax
+    DBG_VALUE $eax, $noreg, !3, !DIExpression(), debug-location !8
+    JMP_1 %bb.3
+
+  bb.3.bb3:
+    liveins: $rax
+    RETQ $eax, debug-location !9
+
+...
+---
+name:            bar
+alignment:       4
+tracksRegLiveness: true
+registers:       []
+liveins:         
+  - { reg: '$rdi', virtual-reg: '' }
+body:             |
+  ; Two DBG_VALUEs, one for eax, the other for zero, merge into bb3. Check that
+  ; livedebugvalues does not propagate anything.
+  ; the location.
+  ; CHECK-LABEL: name: bar
+  ; CHECK-LABEL: bb.1.bb1
+  ; CHECK:       $eax = MOV32rr
+  ; CHECK-NEXT:  DBG_VALUE 0
+  ; CHECK-NEXT:  JMP_1 %bb.3
+  ; CHECK-LABEL: bb.2.bb2
+  ; CHECK:       $eax = ADD32ri8
+  ; CHECK-NEXT:  DBG_VALUE $eax
+  ; CHECK-NEXT:  JMP_1 %bb.3
+  ; CHECK-LABEL: bb.3.bb3
+  ; CHECK-NOT:   DBG_VALUE
+  ; Test for there being a location-list gap between bb1 and bb2, the variable
+  ; should not have a location over the ADD32ri. The range of the last entry
+  ; should not cover the last block.
+  ; RANGES-LABEL: DW_TAG_subprogram
+  ; RANGES:       DW_AT_high_pc (0x[[BARHIGHPC:[0-9a-f]+]])
+  ; RANGES-LABEL: DW_AT_name ("bar")
+  ; RANGES:       DW_AT_location (0x{{[0-9a-f]+}}
+  ; RANGES-NEXT:   [0x{{[0-9a-f]+}}, 0x[[BARADDR:[0-9a-f]+]]): DW_OP_consts +0, DW_OP_stack_value
+  ; RANGES-NEXT:   [
+  ; RANGES-NOT:    0x[[BARADDR]]
+  ; RANGES-NOT:    0x[[BARHIGHPC]]
+  ; RANGES-SAME:   ): DW_OP_reg0 RAX
+
+  bb.0.entry:
+    successors: %bb.1, %bb.2
+    liveins: $rdi
+  
+    $ecx = XOR32rr undef $ecx, undef $ecx, implicit-def $eflags
+    JCC_1 %bb.1, 2, implicit killed $eflags
+    JMP_1 %bb.2
+  
+  bb.1.bb1 (align 4):
+    successors: %bb.3
+    liveins: $ecx, $rdi
+  
+    $eax = MOV32rr killed $ecx, implicit-def $rax
+    DBG_VALUE 0, $noreg, !41, !DIExpression(), debug-location !42
+    JMP_1 %bb.3
+  
+  bb.2.bb2:
+    successors: %bb.3
+    liveins: $rax
+  
+    $eax = ADD32ri8 $eax, 3, implicit-def dead $eflags, implicit killed $rax, implicit-def $rax
+    DBG_VALUE $eax, $noreg, !41, !DIExpression(), debug-location !42
+    JMP_1 %bb.3
+
+  bb.3.bb3:
+    liveins: $rax
+    RETQ $eax, debug-location !42
+
+...
+---
+name:            baz
+alignment:       4
+tracksRegLiveness: true
+registers:       []
+liveins:         
+  - { reg: '$rdi', virtual-reg: '' }
+body:             |
+  ; Two DBG_VALUEs, one for zero, the other for eax, merge into bb3. Check that
+  ; livedebugvalues does not propagate anything.
+  ; the location.
+  ; CHECK-LABEL: name: baz
+  ; CHECK-LABEL: bb.1.bb1
+  ; CHECK:       $eax = MOV32rr
+  ; CHECK-NEXT:  DBG_VALUE $eax
+  ; CHECK-NEXT:  JMP_1 %bb.3
+  ; CHECK-LABEL: bb.2.bb2
+  ; CHECK:       $eax = ADD32ri8
+  ; CHECK-NEXT:  DBG_VALUE 0
+  ; CHECK-NEXT:  JMP_1 %bb.3
+  ; CHECK-LABEL: bb.3.bb3
+  ; CHECK-NOT:   DBG_VALUE
+  ; Test for there being a location-list gap between bb1 and bb2, the variable
+  ; should not have a location over the ADD32ri. The range of the last item
+  ; should not cover the last block.
+  ; RANGES-LABEL: DW_TAG_subprogram
+  ; RANGES:       DW_AT_high_pc (0x[[BAZHIGHPC:[0-9a-f]+]])
+  ; RANGES-LABEL: DW_AT_name ("baz")
+  ; RANGES:       DW_AT_location (0x{{[0-9a-f]+}}
+  ; RANGES-NEXT:   [0x{{[0-9a-f]+}}, 0x[[BAZADDR:[0-9a-f]+]]): DW_OP_reg0 RAX
+  ; RANGES-NEXT:   [
+  ; RANGES-NOT:    0x[[BAZADDR]]
+  ; RANGES-NOT:    0x[[BAZHIGHPC]]
+  ; RANGES-SAME:   ): DW_OP_consts +0, DW_OP_stack_value
+
+  bb.0.entry:
+    successors: %bb.1, %bb.2
+    liveins: $rdi
+  
+    $ecx = XOR32rr undef $ecx, undef $ecx, implicit-def $eflags
+    JCC_1 %bb.1, 2, implicit killed $eflags
+    JMP_1 %bb.2
+  
+  bb.1.bb1 (align 4):
+    successors: %bb.3
+    liveins: $ecx, $rdi
+  
+    $eax = MOV32rr killed $ecx, implicit-def $rax
+    DBG_VALUE $eax, $noreg, !81, !DIExpression(), debug-location !82
+    JMP_1 %bb.3
+  
+  bb.2.bb2:
+    successors: %bb.3
+    liveins: $rax
+  
+    $eax = ADD32ri8 $eax, 3, implicit-def dead $eflags, implicit killed $rax, implicit-def $rax
+    DBG_VALUE 0, $noreg, !81, !DIExpression(), debug-location !82
+    JMP_1 %bb.3
+
+  bb.3.bb3:
+    liveins: $rax
+    RETQ $eax, debug-location !82
+
+...
+---
+name:            qux
+alignment:       4
+tracksRegLiveness: true
+registers:       []
+liveins:         
+  - { reg: '$rdi', virtual-reg: '' }
+body:             |
+  ; Two DBG_VALUEs for zero merging into bb3, Check that livedebugvalues does
+  ; propagate the zero into the merging block.
+  ; CHECK-LABEL: name: qux
+  ; CHECK-LABEL: bb.1.bb1
+  ; CHECK:       $eax = MOV32rr
+  ; CHECK-NEXT:  DBG_VALUE 0
+  ; CHECK-NEXT:  JMP_1 %bb.3
+  ; CHECK-LABEL: bb.2.bb2
+  ; CHECK:       $eax = ADD32ri8
+  ; CHECK-NEXT:  DBG_VALUE 0
+  ; CHECK-NEXT:  JMP_1 %bb.3
+  ; CHECK-LABEL: bb.3.bb3
+  ; CHECK:       DBG_VALUE 0
+  ; Test for there being a location-list gap between bb1 and bb2, the variable
+  ; should not have a location over the ADD32ri. The final entry should cover
+  ; the final block.
+  ; RANGES-LABEL: DW_TAG_subprogram
+  ; RANGES:       DW_AT_high_pc (0x[[QUXHIGHPC:[0-9a-f]+]])
+  ; RANGES-LABEL: DW_AT_name ("qux")
+  ; RANGES:       DW_AT_location (0x{{[0-9a-f]+}}
+  ; RANGES-NEXT:   [0x{{[0-9a-f]+}}, 0x[[QUXADDR:[0-9a-f]+]]): DW_OP_consts +0, DW_OP_stack_value
+  ; RANGES-NOT:    0x[[QUXADDR]]
+  ; RANGES-NEXT:   [0x{{[0-9a-f]+}}, 0x[[QUXHIGHPC]]): DW_OP_consts +0, DW_OP_stack_value
+
+  bb.0.entry:
+    successors: %bb.1, %bb.2
+    liveins: $rdi
+  
+    $ecx = XOR32rr undef $ecx, undef $ecx, implicit-def $eflags
+    JCC_1 %bb.1, 2, implicit killed $eflags
+    JMP_1 %bb.2
+  
+  bb.1.bb1 (align 4):
+    successors: %bb.3
+    liveins: $ecx, $rdi
+  
+    $eax = MOV32rr killed $ecx, implicit-def $rax
+    DBG_VALUE 0, $noreg, !121, !DIExpression(), debug-location !122
+    JMP_1 %bb.3
+  
+  bb.2.bb2:
+    successors: %bb.3
+    liveins: $rax
+  
+    $eax = ADD32ri8 $eax, 3, implicit-def dead $eflags, implicit killed $rax, implicit-def $rax
+    DBG_VALUE 0, $noreg, !121, !DIExpression(), debug-location !122
+    JMP_1 %bb.3
+
+  bb.3.bb3:
+    liveins: $rax
+    RETQ $eax, debug-location !122
+
+...