diff --git a/lib/Transforms/Utils/CloneFunction.cpp b/lib/Transforms/Utils/CloneFunction.cpp
index fe2a606cf71..50340d18508 100644
--- a/lib/Transforms/Utils/CloneFunction.cpp
+++ b/lib/Transforms/Utils/CloneFunction.cpp
@@ -17,6 +17,7 @@
 #include "llvm/Constants.h"
 #include "llvm/DerivedTypes.h"
 #include "llvm/Instructions.h"
+#include "llvm/IntrinsicInst.h"
 #include "llvm/GlobalVariable.h"
 #include "llvm/Function.h"
 #include "llvm/Support/CFG.h"
@@ -181,7 +182,7 @@ namespace {
     const char *NameSuffix;
     ClonedCodeInfo *CodeInfo;
     const TargetData *TD;
-
+    Value *DbgFnStart;
   public:
     PruningFunctionCloner(Function *newFunc, const Function *oldFunc,
                           DenseMap<const Value*, Value*> &valueMap,
@@ -190,7 +191,7 @@ namespace {
                           ClonedCodeInfo *codeInfo,
                           const TargetData *td)
     : NewFunc(newFunc), OldFunc(oldFunc), ValueMap(valueMap), Returns(returns),
-      NameSuffix(nameSuffix), CodeInfo(codeInfo), TD(td) {
+      NameSuffix(nameSuffix), CodeInfo(codeInfo), TD(td), DbgFnStart(NULL) {
     }
 
     /// CloneBlock - The specified block is found to be reachable, clone it and
@@ -231,7 +232,17 @@ void PruningFunctionCloner::CloneBlock(const BasicBlock *BB,
       ValueMap[II] = C;
       continue;
     }
-    
+
+    // Do not clone llvm.dbg.func.start and corresponding llvm.dbg.region.end.
+    if (const DbgFuncStartInst *DFSI = dyn_cast<DbgFuncStartInst>(II)) {
+      DbgFnStart = DFSI->getSubprogram();
+      continue;
+    } 
+    if (const DbgRegionEndInst *DREIS = dyn_cast<DbgRegionEndInst>(II)) {
+      if (DREIS->getContext() == DbgFnStart)
+        continue;
+    }
+      
     Instruction *NewInst = II->clone();
     if (II->hasName())
       NewInst->setName(II->getName()+NameSuffix);
diff --git a/test/Transforms/Inline/llvm.dbg.func.start.ll b/test/Transforms/Inline/llvm.dbg.func.start.ll
new file mode 100644
index 00000000000..abcddc33d94
--- /dev/null
+++ b/test/Transforms/Inline/llvm.dbg.func.start.ll
@@ -0,0 +1,86 @@
+; RUN: llvm-as < %s | opt -inline | llvm-dis | grep func.start | count 3
+; RUN: llvm-as < %s | opt -inline | llvm-dis | grep region.end | count 3
+	%llvm.dbg.anchor.type = type { i32, i32 }
+	%llvm.dbg.basictype.type = type { i32, { }*, i8*, { }*, i32, i64, i64, i64, i32, i32 }
+	%llvm.dbg.compile_unit.type = type { i32, { }*, i32, i8*, i8*, i8*, i1, i1, i8* }
+	%llvm.dbg.composite.type = type { i32, { }*, i8*, { }*, i32, i64, i64, i64, i32, { }*, { }* }
+	%llvm.dbg.derivedtype.type = type { i32, { }*, i8*, { }*, i32, i64, i64, i64, i32, { }* }
+	%llvm.dbg.subprogram.type = type { i32, { }*, { }*, i8*, i8*, i8*, { }*, i32, { }*, i1, i1 }
+	%llvm.dbg.variable.type = type { i32, { }*, i8*, { }*, i32, { }* }
+@llvm.dbg.compile_units = linkonce constant %llvm.dbg.anchor.type { i32 458752, i32 17 }, section "llvm.metadata"		; <%llvm.dbg.anchor.type*> [#uses=1]
+@.str = internal constant [4 x i8] c"a.c\00", section "llvm.metadata"		; <[4 x i8]*> [#uses=1]
+@.str1 = internal constant [6 x i8] c"/tmp/\00", section "llvm.metadata"		; <[6 x i8]*> [#uses=1]
+@.str2 = internal constant [55 x i8] c"4.2.1 (Based on Apple Inc. build 5636) (LLVM build 00)\00", section "llvm.metadata"		; <[55 x i8]*> [#uses=1]
+@llvm.dbg.compile_unit = internal constant %llvm.dbg.compile_unit.type { i32 458769, { }* bitcast (%llvm.dbg.anchor.type* @llvm.dbg.compile_units to { }*), i32 1, i8* getelementptr ([4 x i8]* @.str, i32 0, i32 0), i8* getelementptr ([6 x i8]* @.str1, i32 0, i32 0), i8* getelementptr ([55 x i8]* @.str2, i32 0, i32 0), i1 true, i1 false, i8* null }, section "llvm.metadata"		; <%llvm.dbg.compile_unit.type*> [#uses=1]
+@.str3 = internal constant [4 x i8] c"int\00", section "llvm.metadata"		; <[4 x i8]*> [#uses=1]
+@llvm.dbg.basictype = internal constant %llvm.dbg.basictype.type { i32 458788, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i8* getelementptr ([4 x i8]* @.str3, i32 0, i32 0), { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i32 0, i64 32, i64 32, i64 0, i32 0, i32 5 }, section "llvm.metadata"		; <%llvm.dbg.basictype.type*> [#uses=1]
+@.str4 = internal constant [5 x i8] c"char\00", section "llvm.metadata"		; <[5 x i8]*> [#uses=1]
+@llvm.dbg.basictype5 = internal constant %llvm.dbg.basictype.type { i32 458788, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i8* getelementptr ([5 x i8]* @.str4, i32 0, i32 0), { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i32 0, i64 8, i64 8, i64 0, i32 0, i32 6 }, section "llvm.metadata"		; <%llvm.dbg.basictype.type*> [#uses=1]
+@llvm.dbg.derivedtype = internal constant %llvm.dbg.derivedtype.type { i32 458767, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i8* null, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i32 0, i64 32, i64 32, i64 0, i32 0, { }* bitcast (%llvm.dbg.basictype.type* @llvm.dbg.basictype5 to { }*) }, section "llvm.metadata"		; <%llvm.dbg.derivedtype.type*> [#uses=1]
+@llvm.dbg.array = internal constant [2 x { }*] [ { }* bitcast (%llvm.dbg.basictype.type* @llvm.dbg.basictype to { }*), { }* bitcast (%llvm.dbg.derivedtype.type* @llvm.dbg.derivedtype to { }*) ], section "llvm.metadata"		; <[2 x { }*]*> [#uses=1]
+@llvm.dbg.composite = internal constant %llvm.dbg.composite.type { i32 458773, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i8* null, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i32 0, i64 0, i64 0, i64 0, i32 0, { }* null, { }* bitcast ([2 x { }*]* @llvm.dbg.array to { }*) }, section "llvm.metadata"		; <%llvm.dbg.composite.type*> [#uses=1]
+@llvm.dbg.subprograms = linkonce constant %llvm.dbg.anchor.type { i32 458752, i32 46 }, section "llvm.metadata"		; <%llvm.dbg.anchor.type*> [#uses=1]
+@.str6 = internal constant [4 x i8] c"bar\00", section "llvm.metadata"		; <[4 x i8]*> [#uses=1]
+@llvm.dbg.subprogram = internal constant %llvm.dbg.subprogram.type { i32 458798, { }* bitcast (%llvm.dbg.anchor.type* @llvm.dbg.subprograms to { }*), { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i8* getelementptr ([4 x i8]* @.str6, i32 0, i32 0), i8* getelementptr ([4 x i8]* @.str6, i32 0, i32 0), i8* null, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i32 1, { }* bitcast (%llvm.dbg.composite.type* @llvm.dbg.composite to { }*), i1 false, i1 true }, section "llvm.metadata"		; <%llvm.dbg.subprogram.type*> [#uses=1]
+@.str7 = internal constant [2 x i8] c"c\00", section "llvm.metadata"		; <[2 x i8]*> [#uses=1]
+@llvm.dbg.variable = internal constant %llvm.dbg.variable.type { i32 459009, { }* bitcast (%llvm.dbg.subprogram.type* @llvm.dbg.subprogram to { }*), i8* getelementptr ([2 x i8]* @.str7, i32 0, i32 0), { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i32 1, { }* bitcast (%llvm.dbg.derivedtype.type* @llvm.dbg.derivedtype to { }*) }, section "llvm.metadata"		; <%llvm.dbg.variable.type*> [#uses=1]
+@llvm.dbg.array8 = internal constant [1 x { }*] [ { }* bitcast (%llvm.dbg.basictype.type* @llvm.dbg.basictype to { }*) ], section "llvm.metadata"		; <[1 x { }*]*> [#uses=1]
+@llvm.dbg.composite9 = internal constant %llvm.dbg.composite.type { i32 458773, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i8* null, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i32 0, i64 0, i64 0, i64 0, i32 0, { }* null, { }* bitcast ([1 x { }*]* @llvm.dbg.array8 to { }*) }, section "llvm.metadata"		; <%llvm.dbg.composite.type*> [#uses=1]
+@.str10 = internal constant [5 x i8] c"main\00", section "llvm.metadata"		; <[5 x i8]*> [#uses=1]
+@llvm.dbg.subprogram11 = internal constant %llvm.dbg.subprogram.type { i32 458798, { }* bitcast (%llvm.dbg.anchor.type* @llvm.dbg.subprograms to { }*), { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i8* getelementptr ([5 x i8]* @.str10, i32 0, i32 0), i8* getelementptr ([5 x i8]* @.str10, i32 0, i32 0), i8* null, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*), i32 2, { }* bitcast (%llvm.dbg.composite.type* @llvm.dbg.composite9 to { }*), i1 false, i1 true }, section "llvm.metadata"		; <%llvm.dbg.subprogram.type*> [#uses=1]
+@"\01LC" = internal constant [3 x i8] c"hi\00"		; <[3 x i8]*> [#uses=1]
+
+define i32 @bar(i8* %c) nounwind {
+entry:
+	%c_addr = alloca i8*		; <i8**> [#uses=3]
+	%retval = alloca i32		; <i32*> [#uses=2]
+	%0 = alloca i32		; <i32*> [#uses=2]
+	%"alloca point" = bitcast i32 0 to i32		; <i32> [#uses=0]
+	call void @llvm.dbg.func.start({ }* bitcast (%llvm.dbg.subprogram.type* @llvm.dbg.subprogram to { }*))
+	%1 = bitcast i8** %c_addr to { }*		; <{ }*> [#uses=1]
+	call void @llvm.dbg.declare({ }* %1, { }* bitcast (%llvm.dbg.variable.type* @llvm.dbg.variable to { }*))
+	store i8* %c, i8** %c_addr
+	call void @llvm.dbg.stoppoint(i32 1, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*))
+	%2 = load i8** %c_addr, align 4		; <i8*> [#uses=1]
+	%3 = load i8* %2, align 1		; <i8> [#uses=1]
+	%4 = sext i8 %3 to i32		; <i32> [#uses=1]
+	%5 = add i32 %4, 42		; <i32> [#uses=1]
+	store i32 %5, i32* %0, align 4
+	%6 = load i32* %0, align 4		; <i32> [#uses=1]
+	store i32 %6, i32* %retval, align 4
+	br label %return
+
+return:		; preds = %entry
+	%retval1 = load i32* %retval		; <i32> [#uses=1]
+	call void @llvm.dbg.stoppoint(i32 1, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*))
+	call void @llvm.dbg.region.end({ }* bitcast (%llvm.dbg.subprogram.type* @llvm.dbg.subprogram to { }*))
+	ret i32 %retval1
+}
+
+declare void @llvm.dbg.func.start({ }*) nounwind
+
+declare void @llvm.dbg.declare({ }*, { }*) nounwind
+
+declare void @llvm.dbg.stoppoint(i32, i32, { }*) nounwind
+
+declare void @llvm.dbg.region.end({ }*) nounwind
+
+define i32 @main() nounwind {
+entry:
+	%retval = alloca i32		; <i32*> [#uses=2]
+	%0 = alloca i32		; <i32*> [#uses=2]
+	%"alloca point" = bitcast i32 0 to i32		; <i32> [#uses=0]
+	call void @llvm.dbg.func.start({ }* bitcast (%llvm.dbg.subprogram.type* @llvm.dbg.subprogram11 to { }*))
+	call void @llvm.dbg.stoppoint(i32 2, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*))
+	%1 = call i32 @bar(i8* getelementptr ([3 x i8]* @"\01LC", i32 0, i32 0)) nounwind		; <i32> [#uses=1]
+	store i32 %1, i32* %0, align 4
+	%2 = load i32* %0, align 4		; <i32> [#uses=1]
+	store i32 %2, i32* %retval, align 4
+	br label %return
+
+return:		; preds = %entry
+	%retval1 = load i32* %retval		; <i32> [#uses=1]
+	call void @llvm.dbg.stoppoint(i32 2, i32 0, { }* bitcast (%llvm.dbg.compile_unit.type* @llvm.dbg.compile_unit to { }*))
+	call void @llvm.dbg.region.end({ }* bitcast (%llvm.dbg.subprogram.type* @llvm.dbg.subprogram11 to { }*))
+	ret i32 %retval1
+}