Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_basic_diamond.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_basic_diamond.mir
@@ -0,0 +1,67 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are propogated through a CFG containing
+  ; a diamond that doesn't move or clobber their locations.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1, %bb.2
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+    JCC_1 %bb.2, 4, implicit killed $eflags
+  bb.1.bb1:
+    successors: %bb.3
+    $eax = MOV32ri 0, debug-location !17
+    JMP_1 %bb.3
+  bb.2.bb2:
+    successors: %bb.3
+    $eax = MOV32ri 0, debug-location !17
+  bb.3.bb3:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_basic_diamond_match_clobber.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_basic_diamond_match_clobber.mir
@@ -0,0 +1,69 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are only propogated into the top blocks of
+  ; a diamond when the location is clobbered and not into the successor block.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NEXT:  $ebx = MOV32ri 0, debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NEXT:  $ebx = MOV32ri 0, debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1, %bb.2
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+    JCC_1 %bb.2, 4, implicit killed $eflags
+  bb.1.bb1:
+    successors: %bb.3
+    $ebx = MOV32ri 0, debug-location !17
+    JMP_1 %bb.3
+  bb.2.bb2:
+    successors: %bb.3
+    $ebx = MOV32ri 0, debug-location !17
+  bb.3.bb3:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_basic_diamond_match_move.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_basic_diamond_match_move.mir
@@ -0,0 +1,69 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are propogated correctly through a
+  ; diamond CFG when the location is moved by another intrinsic.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK:       DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK:       DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK:       DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1, %bb.2
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+    JCC_1 %bb.2, 4, implicit killed $eflags
+  bb.1.bb1:
+    successors: %bb.3
+    $eax = MOV32ri 0, debug-location !17
+    DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+    JMP_1 %bb.3
+  bb.2.bb2:
+    successors: %bb.3
+    $eax = MOV32ri 0, debug-location !17
+    DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  bb.3.bb3:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_basic_diamond_one_clobber.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_basic_diamond_one_clobber.mir
@@ -0,0 +1,67 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are not propogated into a successor block
+  ; of a diamond CFG that clobbers its location.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1, %bb.2
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+    JCC_1 %bb.2, 4, implicit killed $eflags
+  bb.1.bb1:
+    successors: %bb.3
+    $ebx = MOV32ri 0, debug-location !17
+    JMP_1 %bb.3
+  bb.2.bb2:
+    successors: %bb.3
+    $eax = MOV32ri 0, debug-location !17
+  bb.3.bb3:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_basic_diamond_one_move.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_basic_diamond_one_move.mir
@@ -0,0 +1,71 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are not propogated into a successor block
+  ; of a diamond CFG that moves its location.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NEXT:  $eax = MOV32ri 0, debug-location !17
+  ; CHECK:       DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17 
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NOT:   DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1, %bb.2
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+    JCC_1 %bb.2, 4, implicit killed $eflags
+  bb.1.bb1:
+    successors: %bb.3
+    $eax = MOV32ri 0, debug-location !17
+    DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+    JMP_1 %bb.3
+  bb.2.bb2:
+    successors: %bb.3
+    $eax = MOV32ri 0, debug-location !17
+  bb.3.bb3:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_basic_loop.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_basic_loop.mir
@@ -0,0 +1,66 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are propogated throughout a CFG with a
+  ; loop that doesn't move or clobber it's location.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2
+    $eax = MOV32ri 0, debug-location !17
+  bb.2.bb2:
+    successors: %bb.1, %bb.3
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.3.bb3:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_bb_to_bb.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_bb_to_bb.mir
@@ -0,0 +1,65 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are propogated throughout a CFG with a
+  ; loop that doesn't move or clobber it's location.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name:            _Z8bb_to_bb
+body:             |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2
+    $eax = MOV32ri 0, debug-location !17
+  bb.2.bb2:
+    successors: %bb.3
+    $eax = MOV32ri 0, debug-location !17
+  bb.3.bb3:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_bb_to_bb_clobbered.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_bb_to_bb_clobbered.mir
@@ -0,0 +1,65 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are propogated into basic blocks with no
+  ; control flow when it's location is clobbered.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name:            _Z8bb_to_bb
+body:             |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2
+    $ebx = MOV32ri 0, debug-location !17
+  bb.2.bb2:
+    successors: %bb.3
+    $eax = MOV32ri 0, debug-location !17
+  bb.3.bb3:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_bb_to_bb_move_to_clobber.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_bb_to_bb_move_to_clobber.mir
@@ -0,0 +1,71 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are correctly propogated into blocks with
+  ; no control flow when a location is moved and then clobbered.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NEXT:  $eax = MOV32ri 0, debug-location !17
+  ; CHECK:       DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK:       DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NOT:   DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name:            _Z8bb_to_bb
+body:             |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2
+    $eax = MOV32ri 0, debug-location !17
+    DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+    $ebx = MOV32ri 0, debug-location !17
+  bb.2.bb2:
+    successors: %bb.3
+    $eax = MOV32ri 0, debug-location !17
+  bb.3.bb3:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_break.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_break.mir
@@ -0,0 +1,72 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are correctly propogated into a loop with
+  ; break.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    br label %bb4, !dbg !17
+  bb4:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2
+    $eax = MOV32ri 0, debug-location !17
+  bb.2.bb2:
+    successors: %bb.3, %bb.4
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.4, 4, implicit killed $eflags
+  bb.3.bb3:
+    successors: %bb.1, %bb.4
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.4.bb4:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_break_clobbered.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_break_clobbered.mir
@@ -0,0 +1,72 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are correctly propogated when dealing
+  ; with a loop that clobbers its location and has two exit points (a break).
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    br label %bb4, !dbg !17
+  bb4:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2
+    $eax = MOV32ri 0, debug-location !17
+  bb.2.bb2:
+    successors: %bb.3, %bb.4
+    $ebx = MOV32ri 0, debug-location !17
+    JCC_1 %bb.4, 4, implicit killed $eflags
+  bb.3.bb3:
+    successors: %bb.1, %bb.4
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.4.bb4:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_clobbered.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_clobbered.mir
@@ -0,0 +1,69 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are not propogated into a loop that
+  ; clobbers it's location.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\test")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  bb.1.bb1:
+    successors: %bb.2
+    $eax = MOV32ri 0, debug-location !17
+
+  bb.2.bb2:
+    successors: %bb.1, %bb.3
+    $ebx = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+
+  bb.3.bb3:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_diamond.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_diamond.mir
@@ -0,0 +1,82 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are propogated into a loop with
+  ; diamond pattern and beyond.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.4.bb4:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.5.bb5:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    br label %bb3, !dbg !17
+  bb4:
+    br label %bb3, !dbg !17
+  bb5:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2, %bb.3
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.3, 4, implicit killed $eflags
+  bb.2.bb2:
+    successors: %bb.4
+    $eax = MOV32ri 0, debug-location !17
+    JMP_1 %bb.4
+  bb.3.bb3:
+    successors: %bb.4
+    $eax = MOV32ri 0, debug-location !17
+  bb.4.bb4:
+    successors: %bb.1, %bb.5
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.5.bb5:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_diamond_clobber.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_diamond_clobber.mir
@@ -0,0 +1,82 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are not propogated into a loop with 
+  ; diamond pattern that clobbers it's location.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.4.bb4:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.5.bb5:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    br label %bb3, !dbg !17
+  bb4:
+    br label %bb3, !dbg !17
+  bb5:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2, %bb.3
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.3, 4, implicit killed $eflags
+  bb.2.bb2:
+    successors: %bb.4
+    $eax = MOV32ri 0, debug-location !17
+    JMP_1 %bb.4
+  bb.3.bb3:
+    successors: %bb.4
+    $ebx = MOV32ri 0, debug-location !17
+  bb.4.bb4:
+    successors: %bb.1, %bb.5
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.5.bb5:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_diamond_move.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_diamond_move.mir
@@ -0,0 +1,88 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are propogated into a loop with 
+  ; diamond pattern but not beyond.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK:       DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK:       DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK:       DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.4.bb4:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK:       DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.5.bb5:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK:       DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    br label %bb3, !dbg !17
+  bb4:
+    br label %bb3, !dbg !17
+  bb5:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2, %bb.3
+    $eax = MOV32ri 0, debug-location !17
+    DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+    JCC_1 %bb.3, 4, implicit killed $eflags
+  bb.2.bb2:
+    successors: %bb.4
+    $ebx = MOV32ri 0, debug-location !17
+    JMP_1 %bb.4
+  bb.3.bb3:
+    successors: %bb.4
+    $ebx = MOV32ri 0, debug-location !17
+  bb.4.bb4:
+    successors: %bb.1, %bb.5
+    $ebx = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.5.bb5:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_early_clobber.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_early_clobber.mir
@@ -0,0 +1,66 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are not propogated into a loop that
+  ; clobbers it's location.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2
+    $ebx = MOV32ri 0, debug-location !17
+  bb.2.bb2:
+    successors: %bb.1, %bb.3
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.3.bb3:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_two_backedge.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_two_backedge.mir
@@ -0,0 +1,74 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are propogated into a loop that has two
+  ; backedges and beyond.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.4.bb4:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    br label %bb4, !dbg !17
+  bb4:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2
+    $eax = MOV32ri 0, debug-location !17
+  bb.2.bb2:
+    successors: %bb.1, %bb.3
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.3.bb3:
+    successors: %bb.1, %bb.4
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.4.bb4:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_two_backedge_clobbered.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_two_backedge_clobbered.mir
@@ -0,0 +1,74 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are not propogated into loops that clobber
+  ; their locations and have two backedges.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.4.bb4:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    br label %bb4, !dbg !17
+  bb4:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2
+    $eax = MOV32ri 0, debug-location !17
+  bb.2.bb2:
+    successors: %bb.1, %bb.3
+    $ebx = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.3.bb3:
+    successors: %bb.1, %bb.4
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.4.bb4:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_within_loop.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_within_loop.mir
@@ -0,0 +1,81 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are propogated into loops within loops.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.4.bb4:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.5.bb5:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    br label %bb3, !dbg !17
+  bb4:
+    br label %bb3, !dbg !17
+  bb5:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2, %bb.4
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.4, 4, implicit killed $eflags
+  bb.2.bb2:
+    successors: %bb.3
+    $eax = MOV32ri 0, debug-location !17
+  bb.3.bb3:
+    successors: %bb.2, %bb.4
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.2, 4, implicit killed $eflags
+  bb.4.bb4:
+    successors: %bb.1, %bb.5
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.5.bb5:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_within_loop_clobbered.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_within_loop_clobbered.mir
@@ -0,0 +1,82 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are not propogated into loops with inner
+  ; loops that clobber their locations.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.4.bb4:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.5.bb5:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    br label %bb3, !dbg !17
+  bb4:
+    br label %bb3, !dbg !17
+  bb5:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2, %bb.4
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.4, 4, implicit killed $eflags
+  bb.2.bb2:
+    successors: %bb.3
+    $eax = MOV32ri 0, debug-location !17
+  bb.3.bb3:
+    successors: %bb.2, %bb.4
+    $ebx = MOV32ri 0, debug-location !17
+    JCC_1 %bb.2, 4, implicit killed $eflags
+  bb.4.bb4:
+    successors: %bb.1, %bb.5
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.5.bb5:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_within_loop_moved.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_within_loop_moved.mir
@@ -0,0 +1,89 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are not propogated into loops with inner
+  ; loops that move their locations.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NOT:   DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NOT:   DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NOT:   DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK:       DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.4.bb4:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NOT:   DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.5.bb5:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NOT:   DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    br label %bb3, !dbg !17
+  bb4:
+    br label %bb3, !dbg !17
+  bb5:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2, %bb.4
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.4, 4, implicit killed $eflags
+  bb.2.bb2:
+    successors: %bb.3
+    $eax = MOV32ri 0, debug-location !17
+  bb.3.bb3:
+    successors: %bb.2, %bb.4
+    $eax = MOV32ri 0, debug-location !17
+    DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+    JCC_1 %bb.2, 4, implicit killed $eflags
+  bb.4.bb4:
+    successors: %bb.1, %bb.5
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.5.bb5:
+    RETQ $eax, debug-location !17
+...
Index: llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_within_loop_outer_moved.mir
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/MIR/X86/livedebugvalues_loop_within_loop_outer_moved.mir
@@ -0,0 +1,90 @@
+--- |
+  ; RUN: llc %s -run-pass=livedebugvalues -o - | FileCheck %s
+
+  ; Check that debug value intrinsics are not propogated into loops with inner
+  ; loops that move their locations.
+
+  ; CHECK-LABEL: bb.0.entry:
+  ; CHECK:       DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NOT:   DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.1.bb1:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NOT:   DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.2.bb2:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NOT:   DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.3.bb3:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-NOT:   DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.4.bb4:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK:       DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK-LABEL: bb.5.bb5:
+  ; CHECK-NOT:   DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  ; CHECK:       DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+
+
+  define i32 @_Z8bb_to_bb() local_unnamed_addr !dbg !12 {
+  entry:
+    br label %bb1, !dbg !17
+  bb1:
+    br label %bb2, !dbg !17
+  bb2:
+    br label %bb3, !dbg !17
+  bb3:
+    br label %bb3, !dbg !17
+  bb4:
+    br label %bb3, !dbg !17
+  bb5:
+    ret i32 0, !dbg !17
+  }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!7, !8, !9, !10}
+  !llvm.ident = !{!11}
+  !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 8.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !3, debugInfoForProfiling: true, nameTableKind: None)
+  !1 = !DIFile(filename: "main.cpp", directory: "F:\")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DIGlobalVariableExpression(var: !5, expr: !DIExpression())
+  !5 = distinct !DIGlobalVariable(name: "start", scope: !0, file: !1, line: 4, type: !6, isLocal: false, isDefinition: true)
+  !6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !7 = !{i32 2, !"Dwarf Version", i32 4}
+  !8 = !{i32 2, !"Debug Info Version", i32 3}
+  !9 = !{i32 1, !"wchar_size", i32 2}
+  !10 = !{i32 7, !"PIC Level", i32 2}
+  !11 = !{!"clang version 8.0.0"}
+  !12 = distinct !DISubprogram(name: "bb_to_bb", linkageName: "bb_to_bb", scope: !1, file: !1, line: 6, type: !13, scopeLine: 6, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !15)
+  !13 = !DISubroutineType(types: !14)
+  !14 = !{!6, !6}
+  !15 = !{!16}
+  !16 = !DILocalVariable(name: "myVar", scope: !12, file: !1, line: 7, type: !6)
+  !17 = !DILocation(line: 10, scope: !12)
+
+...
+---
+name: _Z8bb_to_bb
+body:  |
+  bb.0.entry:
+    successors: %bb.1
+    $ebx = MOV32ri 0, debug-location !17
+    DBG_VALUE $ebx, $noreg, !16, !DIExpression(), debug-location !17
+  bb.1.bb1:
+    successors: %bb.2, %bb.4
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.4, 4, implicit killed $eflags
+  bb.2.bb2:
+    successors: %bb.3
+    $eax = MOV32ri 0, debug-location !17
+  bb.3.bb3:
+    successors: %bb.2, %bb.4
+    $eax = MOV32ri 0, debug-location !17
+    JCC_1 %bb.2, 4, implicit killed $eflags
+  bb.4.bb4:
+    successors: %bb.1, %bb.5
+    $eax = MOV32ri 0, debug-location !17
+    DBG_VALUE $eax, $noreg, !16, !DIExpression(), debug-location !17
+    JCC_1 %bb.1, 4, implicit killed $eflags
+  bb.5.bb5:
+    RETQ $eax, debug-location !17
+...