Index: lib/CodeGen/BranchFolding.cpp
===================================================================
--- lib/CodeGen/BranchFolding.cpp
+++ lib/CodeGen/BranchFolding.cpp
@@ -1515,7 +1515,7 @@
   // branch from condition setting instruction.
   MachineBasicBlock::iterator PI = Loc;
   --PI;
-  while (PI != MBB->begin() && Loc->isDebugValue())
+  while (PI != MBB->begin() && PI->isDebugValue())
     --PI;
 
   bool IsDef = false;
Index: test/CodeGen/X86/dbg-changes-codegen-branch-folding.ll
===================================================================
--- test/CodeGen/X86/dbg-changes-codegen-branch-folding.ll
+++ test/CodeGen/X86/dbg-changes-codegen-branch-folding.ll
@@ -0,0 +1,213 @@
+; RUN: llc -march=x86-64 < %s | FileCheck %s
+; RUN: opt -strip-debug < %s | llc -march=x86-64 | FileCheck %s
+; BZ #19051. Minor code-motion difference with -g.
+; Presence of debug info shouldn't affect the codegen. Make sure that
+; we generated the same code sequence with and without debug info. 
+;
+; CHECK:      callq   _Z3fooPcjPKc
+; CHECK:      callq   _Z3fooPcjPKc
+; CHECK:      leaq    (%rsp), %rdi
+; CHECK:      movl    $4, %esi
+; CHECK:      testl   {{%[a-z]+}}, {{%[a-z]+}}
+; CHECK:      je     .LBB0_4
+
+; The following bitcode was generated with:
+;    clang -emit-llvm -S -O2 -g
+; from this source:
+
+; extern void foo(char *dst,unsigned siz,const char *src);
+; extern const char * i2str(int);
+;
+; struct AAA3 {
+;  AAA3(const char *value) { foo(text,sizeof(text),value);}
+;  void operator=(const char *value) { foo(text,sizeof(text),value);}
+;  operator const char*() const { return text;}
+;  char text[4];
+; };
+;
+; void bar (int param1,int param2)  {
+;   const char * temp(0);
+;
+;   if (param2) {
+;     temp = i2str(param2);
+;   }
+;   AAA3 var1("");
+;   AAA3 var2("");
+;
+;   if (param1)
+;     var2 = "+";
+;   else
+;     var2 = "-";
+;   var1 = "";
+; }
+
+
+; ModuleID = 'test.cpp'
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+%struct.AAA3 = type { [4 x i8] }
+
+@.str = private unnamed_addr constant [1 x i8] zeroinitializer, align 1
+@.str1 = private unnamed_addr constant [2 x i8] c"+\00", align 1
+@.str2 = private unnamed_addr constant [2 x i8] c"-\00", align 1
+
+; Function Attrs: uwtable
+define void @_Z3barii(i32 %param1, i32 %param2) #0 {
+entry:
+  %var1 = alloca %struct.AAA3, align 1
+  %var2 = alloca %struct.AAA3, align 1
+  call void @llvm.dbg.value(metadata !{i32 %param1}, i64 0, metadata !33), !dbg !50
+  call void @llvm.dbg.value(metadata !{i32 %param2}, i64 0, metadata !34), !dbg !50
+  call void @llvm.dbg.value(metadata !51, i64 0, metadata !35), !dbg !52
+  %tobool = icmp eq i32 %param2, 0, !dbg !53
+  br i1 %tobool, label %if.end, label %if.then, !dbg !53
+
+if.then:                                          ; preds = %entry
+  %call = call i8* @_Z5i2stri(i32 %param2), !dbg !55
+  call void @llvm.dbg.value(metadata !{i8* %call}, i64 0, metadata !35), !dbg !55
+  br label %if.end, !dbg !57
+
+if.end:                                           ; preds = %entry, %if.then
+  call void @llvm.dbg.declare(metadata !{%struct.AAA3* %var1}, metadata !36), !dbg !58
+  call void @llvm.dbg.value(metadata !{%struct.AAA3* %var1}, i64 0, metadata !59), !dbg !60
+  call void @llvm.dbg.value(metadata !61, i64 0, metadata !62), !dbg !63
+  %arraydecay.i = getelementptr inbounds %struct.AAA3* %var1, i64 0, i32 0, i64 0, !dbg !64
+  call void @_Z3fooPcjPKc(i8* %arraydecay.i, i32 4, i8* getelementptr inbounds ([1 x i8]* @.str, i64 0, i64 0)), !dbg !64
+  call void @llvm.dbg.declare(metadata !{%struct.AAA3* %var2}, metadata !37), !dbg !66
+  call void @llvm.dbg.value(metadata !{%struct.AAA3* %var2}, i64 0, metadata !67), !dbg !68
+  call void @llvm.dbg.value(metadata !61, i64 0, metadata !69), !dbg !70
+  %arraydecay.i5 = getelementptr inbounds %struct.AAA3* %var2, i64 0, i32 0, i64 0, !dbg !71
+  call void @_Z3fooPcjPKc(i8* %arraydecay.i5, i32 4, i8* getelementptr inbounds ([1 x i8]* @.str, i64 0, i64 0)), !dbg !71
+  %tobool1 = icmp eq i32 %param1, 0, !dbg !72
+  br i1 %tobool1, label %if.else, label %if.then2, !dbg !72
+
+if.then2:                                         ; preds = %if.end
+  call void @llvm.dbg.value(metadata !{%struct.AAA3* %var2}, i64 0, metadata !74), !dbg !76
+  call void @llvm.dbg.value(metadata !77, i64 0, metadata !78), !dbg !79
+  call void @_Z3fooPcjPKc(i8* %arraydecay.i5, i32 4, i8* getelementptr inbounds ([2 x i8]* @.str1, i64 0, i64 0)), !dbg !79
+  br label %if.end3, !dbg !75
+
+if.else:                                          ; preds = %if.end
+  call void @llvm.dbg.value(metadata !{%struct.AAA3* %var2}, i64 0, metadata !80), !dbg !82
+  call void @llvm.dbg.value(metadata !83, i64 0, metadata !84), !dbg !85
+  call void @_Z3fooPcjPKc(i8* %arraydecay.i5, i32 4, i8* getelementptr inbounds ([2 x i8]* @.str2, i64 0, i64 0)), !dbg !85
+  br label %if.end3
+
+if.end3:                                          ; preds = %if.else, %if.then2
+  call void @llvm.dbg.value(metadata !{%struct.AAA3* %var1}, i64 0, metadata !86), !dbg !88
+  call void @llvm.dbg.value(metadata !61, i64 0, metadata !89), !dbg !90
+  call void @_Z3fooPcjPKc(i8* %arraydecay.i, i32 4, i8* getelementptr inbounds ([1 x i8]* @.str, i64 0, i64 0)), !dbg !90
+  ret void, !dbg !91
+}
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.declare(metadata, metadata) #1
+
+declare i8* @_Z5i2stri(i32) #2
+
+declare void @_Z3fooPcjPKc(i8*, i32, i8*) #2
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.value(metadata, i64, metadata) #1
+
+attributes #0 = { uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone }
+attributes #2 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!47, !48}
+!llvm.ident = !{!49}
+
+!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.5.0 (trunk 202934)", i1 true, metadata !"", i32 0, metadata !2, metadata !3, metadata !26, metadata !2, metadata !2, metadata !"", i32 1} ; [ DW_TAG_compile_unit ] [/home/kromanova/test.cpp] [DW_LANG_C_plus_plus]
+!1 = metadata !{metadata !"test.cpp", metadata !"/home/kromanova"}
+!2 = metadata !{}
+!3 = metadata !{metadata !4}
+!4 = metadata !{i32 786451, metadata !1, null, metadata !"AAA3", i32 8, i64 32, i64 8, i32 0, i32 0, null, metadata !5, i32 0, null, null, metadata !"_ZTS4AAA3"} ; [ DW_TAG_structure_type ] [AAA3] [line 8, size 32, align 8, offset 0] [def] [from ]
+!5 = metadata !{metadata !6, metadata !11, metadata !18, metadata !20}
+!6 = metadata !{i32 786445, metadata !1, metadata !"_ZTS4AAA3", metadata !"text", i32 12, i64 32, i64 8, i64 0, i32 0, metadata !7} ; [ DW_TAG_member ] [text] [line 12, size 32, align 8, offset 0] [from ]
+!7 = metadata !{i32 786433, null, null, metadata !"", i32 0, i64 32, i64 8, i32 0, i32 0, metadata !8, metadata !9, i32 0, null, null, null} ; [ DW_TAG_array_type ] [line 0, size 32, align 8, offset 0] [from char]
+!8 = metadata !{i32 786468, null, null, metadata !"char", i32 0, i64 8, i64 8, i64 0, i32 0, i32 6} ; [ DW_TAG_base_type ] [char] [line 0, size 8, align 8, offset 0, enc DW_ATE_signed_char]
+!9 = metadata !{metadata !10}
+!10 = metadata !{i32 786465, i64 0, i64 4}        ; [ DW_TAG_subrange_type ] [0, 3]
+!11 = metadata !{i32 786478, metadata !1, metadata !"_ZTS4AAA3", metadata !"AAA3", metadata !"AAA3", metadata !"", i32 9, metadata !12, i1 false, i1 false, i32 0, i32 0, null, i32 256, i1 true, null, null, i32 0, metadata !17, i32 9} ; [ DW_TAG_subprogram ] [line 9] [AAA3]
+!12 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !13, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!13 = metadata !{null, metadata !14, metadata !15}
+!14 = metadata !{i32 786447, null, null, metadata !"", i32 0, i64 64, i64 64, i64 0, i32 1088, metadata !"_ZTS4AAA3"} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [artificial] [from _ZTS4AAA3]
+!15 = metadata !{i32 786447, null, null, metadata !"", i32 0, i64 64, i64 64, i64 0, i32 0, metadata !16} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [from ]
+!16 = metadata !{i32 786470, null, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, metadata !8} ; [ DW_TAG_const_type ] [line 0, size 0, align 0, offset 0] [from char]
+!17 = metadata !{i32 786468}
+!18 = metadata !{i32 786478, metadata !1, metadata !"_ZTS4AAA3", metadata !"operator=", metadata !"operator=", metadata !"_ZN4AAA3aSEPKc", i32 10, metadata !12, i1 false, i1 false, i32 0, i32 0, null, i32 256, i1 true, null, null, i32 0, metadata !19, i32 10} ; [ DW_TAG_subprogram ] [line 10] [operator=]
+!19 = metadata !{i32 786468}
+!20 = metadata !{i32 786478, metadata !1, metadata !"_ZTS4AAA3", metadata !"operator const char *", metadata !"operator const char *", metadata !"_ZNK4AAA3cvPKcEv", i32 11, metadata !21, i1 false, i1 false, i32 0, i32 0, null, i32 256, i1 true, null, null, i32 0, metadata !25, i32 11} ; [ DW_TAG_subprogram ] [line 11] [operator const char *]
+!21 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !22, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!22 = metadata !{metadata !15, metadata !23}
+!23 = metadata !{i32 786447, null, null, metadata !"", i32 0, i64 64, i64 64, i64 0, i32 1088, metadata !24} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [artificial] [from ]
+!24 = metadata !{i32 786470, null, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, metadata !"_ZTS4AAA3"} ; [ DW_TAG_const_type ] [line 0, size 0, align 0, offset 0] [from _ZTS4AAA3]
+!25 = metadata !{i32 786468}
+!26 = metadata !{metadata !27, metadata !38, metadata !43}
+!27 = metadata !{i32 786478, metadata !1, metadata !28, metadata !"bar", metadata !"bar", metadata !"_Z3barii", i32 15, metadata !29, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, void (i32, i32)* @_Z3barii, null, null, metadata !32, i32 15} ; [ DW_TAG_subprogram ] [line 15] [def] [bar]
+!28 = metadata !{i32 786473, metadata !1}         ; [ DW_TAG_file_type ] [/home/kromanova/test.cpp]
+!29 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !30, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!30 = metadata !{null, metadata !31, metadata !31}
+!31 = metadata !{i32 786468, null, null, metadata !"int", i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed]
+!32 = metadata !{metadata !33, metadata !34, metadata !35, metadata !36, metadata !37}
+!33 = metadata !{i32 786689, metadata !27, metadata !"param1", metadata !28, i32 16777231, metadata !31, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [param1] [line 15]
+!34 = metadata !{i32 786689, metadata !27, metadata !"param2", metadata !28, i32 33554447, metadata !31, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [param2] [line 15]
+!35 = metadata !{i32 786688, metadata !27, metadata !"temp", metadata !28, i32 16, metadata !15, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [temp] [line 16]
+!36 = metadata !{i32 786688, metadata !27, metadata !"var1", metadata !28, i32 21, metadata !4, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [var1] [line 21]
+!37 = metadata !{i32 786688, metadata !27, metadata !"var2", metadata !28, i32 22, metadata !4, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [var2] [line 22]
+!38 = metadata !{i32 786478, metadata !1, metadata !"_ZTS4AAA3", metadata !"operator=", metadata !"operator=", metadata !"_ZN4AAA3aSEPKc", i32 10, metadata !12, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, null, null, metadata !18, metadata !39, i32 10} ; [ DW_TAG_subprogram ] [line 10] [def] [operator=]
+!39 = metadata !{metadata !40, metadata !42}
+!40 = metadata !{i32 786689, metadata !38, metadata !"this", null, i32 16777216, metadata !41, i32 1088, i32 0} ; [ DW_TAG_arg_variable ] [this] [line 0]
+!41 = metadata !{i32 786447, null, null, metadata !"", i32 0, i64 64, i64 64, i64 0, i32 0, metadata !"_ZTS4AAA3"} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [from _ZTS4AAA3]
+!42 = metadata !{i32 786689, metadata !38, metadata !"value", metadata !28, i32 33554442, metadata !15, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [value] [line 10]
+!43 = metadata !{i32 786478, metadata !1, metadata !"_ZTS4AAA3", metadata !"AAA3", metadata !"AAA3", metadata !"_ZN4AAA3C2EPKc", i32 9, metadata !12, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 true, null, null, metadata !11, metadata !44, i32 9} ; [ DW_TAG_subprogram ] [line 9] [def] [AAA3]
+!44 = metadata !{metadata !45, metadata !46}
+!45 = metadata !{i32 786689, metadata !43, metadata !"this", null, i32 16777216, metadata !41, i32 1088, i32 0} ; [ DW_TAG_arg_variable ] [this] [line 0]
+!46 = metadata !{i32 786689, metadata !43, metadata !"value", metadata !28, i32 33554441, metadata !15, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [value] [line 9]
+!47 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
+!48 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
+!49 = metadata !{metadata !"clang version 3.5.0 (trunk 202934)"}
+!50 = metadata !{i32 15, i32 0, metadata !27, null}
+!51 = metadata !{i8* null}
+!52 = metadata !{i32 16, i32 0, metadata !27, null}
+!53 = metadata !{i32 18, i32 0, metadata !54, null}
+!54 = metadata !{i32 786443, metadata !1, metadata !27, i32 18, i32 0, i32 0, i32 0} ; [ DW_TAG_lexical_block ] [/home/kromanova/test.cpp]
+!55 = metadata !{i32 19, i32 0, metadata !56, null}
+!56 = metadata !{i32 786443, metadata !1, metadata !54, i32 18, i32 0, i32 0, i32 1} ; [ DW_TAG_lexical_block ] [/home/kromanova/test.cpp]
+!57 = metadata !{i32 20, i32 0, metadata !56, null}
+!58 = metadata !{i32 21, i32 0, metadata !27, null}
+!59 = metadata !{i32 786689, metadata !43, metadata !"this", null, i32 16777216, metadata !41, i32 1088, metadata !58} ; [ DW_TAG_arg_variable ] [this] [line 0]
+!60 = metadata !{i32 0, i32 0, metadata !43, metadata !58}
+!61 = metadata !{i8* getelementptr inbounds ([1 x i8]* @.str, i64 0, i64 0)}
+!62 = metadata !{i32 786689, metadata !43, metadata !"value", metadata !28, i32 33554441, metadata !15, i32 0, metadata !58} ; [ DW_TAG_arg_variable ] [value] [line 9]
+!63 = metadata !{i32 9, i32 0, metadata !43, metadata !58}
+!64 = metadata !{i32 9, i32 0, metadata !65, metadata !58}
+!65 = metadata !{i32 786443, metadata !1, metadata !43, i32 9, i32 0, i32 0, i32 3} ; [ DW_TAG_lexical_block ] [/home/kromanova/test.cpp]
+!66 = metadata !{i32 22, i32 0, metadata !27, null}
+!67 = metadata !{i32 786689, metadata !43, metadata !"this", null, i32 16777216, metadata !41, i32 1088, metadata !66} ; [ DW_TAG_arg_variable ] [this] [line 0]
+!68 = metadata !{i32 0, i32 0, metadata !43, metadata !66}
+!69 = metadata !{i32 786689, metadata !43, metadata !"value", metadata !28, i32 33554441, metadata !15, i32 0, metadata !66} ; [ DW_TAG_arg_variable ] [value] [line 9]
+!70 = metadata !{i32 9, i32 0, metadata !43, metadata !66}
+!71 = metadata !{i32 9, i32 0, metadata !65, metadata !66}
+!72 = metadata !{i32 24, i32 0, metadata !73, null}
+!73 = metadata !{i32 786443, metadata !1, metadata !27, i32 24, i32 0, i32 0, i32 2} ; [ DW_TAG_lexical_block ] [/home/kromanova/test.cpp]
+!74 = metadata !{i32 786689, metadata !38, metadata !"this", null, i32 16777216, metadata !41, i32 1088, metadata !75} ; [ DW_TAG_arg_variable ] [this] [line 0]
+!75 = metadata !{i32 25, i32 0, metadata !73, null}
+!76 = metadata !{i32 0, i32 0, metadata !38, metadata !75}
+!77 = metadata !{i8* getelementptr inbounds ([2 x i8]* @.str1, i64 0, i64 0)}
+!78 = metadata !{i32 786689, metadata !38, metadata !"value", metadata !28, i32 33554442, metadata !15, i32 0, metadata !75} ; [ DW_TAG_arg_variable ] [value] [line 10]
+!79 = metadata !{i32 10, i32 0, metadata !38, metadata !75}
+!80 = metadata !{i32 786689, metadata !38, metadata !"this", null, i32 16777216, metadata !41, i32 1088, metadata !81} ; [ DW_TAG_arg_variable ] [this] [line 0]
+!81 = metadata !{i32 27, i32 0, metadata !73, null}
+!82 = metadata !{i32 0, i32 0, metadata !38, metadata !81}
+!83 = metadata !{i8* getelementptr inbounds ([2 x i8]* @.str2, i64 0, i64 0)}
+!84 = metadata !{i32 786689, metadata !38, metadata !"value", metadata !28, i32 33554442, metadata !15, i32 0, metadata !81} ; [ DW_TAG_arg_variable ] [value] [line 10]
+!85 = metadata !{i32 10, i32 0, metadata !38, metadata !81}
+!86 = metadata !{i32 786689, metadata !38, metadata !"this", null, i32 16777216, metadata !41, i32 1088, metadata !87} ; [ DW_TAG_arg_variable ] [this] [line 0]
+!87 = metadata !{i32 28, i32 0, metadata !27, null}
+!88 = metadata !{i32 0, i32 0, metadata !38, metadata !87}
+!89 = metadata !{i32 786689, metadata !38, metadata !"value", metadata !28, i32 33554442, metadata !15, i32 0, metadata !87} ; [ DW_TAG_arg_variable ] [value] [line 10]
+!90 = metadata !{i32 10, i32 0, metadata !38, metadata !87}
+!91 = metadata !{i32 29, i32 0, metadata !27, null}