Index: llvm/trunk/lib/Target/XCore/XCoreFrameLowering.cpp
===================================================================
--- llvm/trunk/lib/Target/XCore/XCoreFrameLowering.cpp
+++ llvm/trunk/lib/Target/XCore/XCoreFrameLowering.cpp
@@ -228,7 +228,9 @@
   const XCoreInstrInfo &TII =
     *static_cast<const XCoreInstrInfo*>(MF.getTarget().getInstrInfo());
   XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
-  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
+  // Debug location must be unknown since the first debug location is used
+  // to determine the end of the prologue.
+  DebugLoc dl;
 
   if (MFI->getMaxAlignment() > getStackAlignment())
     report_fatal_error("emitPrologue unsupported alignment: "
@@ -416,7 +418,7 @@
   bool emitFrameMoves = XCoreRegisterInfo::needsFrameMoves(*MF);
 
   DebugLoc DL;
-  if (MI != MBB.end())
+  if (MI != MBB.end() && !MI->isDebugValue())
     DL = MI->getDebugLoc();
 
   for (std::vector<CalleeSavedInfo>::const_iterator it = CSI.begin();
Index: llvm/trunk/lib/Target/XCore/XCoreInstrInfo.cpp
===================================================================
--- llvm/trunk/lib/Target/XCore/XCoreInstrInfo.cpp
+++ llvm/trunk/lib/Target/XCore/XCoreInstrInfo.cpp
@@ -373,7 +373,8 @@
                                          const TargetRegisterInfo *TRI) const
 {
   DebugLoc DL;
-  if (I != MBB.end()) DL = I->getDebugLoc();
+  if (I != MBB.end() && !I->isDebugValue())
+    DL = I->getDebugLoc();
   MachineFunction *MF = MBB.getParent();
   const MachineFrameInfo &MFI = *MF->getFrameInfo();
   MachineMemOperand *MMO =
@@ -395,7 +396,8 @@
                                           const TargetRegisterInfo *TRI) const
 {
   DebugLoc DL;
-  if (I != MBB.end()) DL = I->getDebugLoc();
+  if (I != MBB.end() && !I->isDebugValue())
+    DL = I->getDebugLoc();
   MachineFunction *MF = MBB.getParent();
   const MachineFrameInfo &MFI = *MF->getFrameInfo();
   MachineMemOperand *MMO =
@@ -440,7 +442,8 @@
                                               MachineBasicBlock::iterator MI,
                                               unsigned Reg, uint64_t Value) const {
   DebugLoc dl;
-  if (MI != MBB.end()) dl = MI->getDebugLoc();
+  if (MI != MBB.end() && !MI->isDebugValue())
+    dl = MI->getDebugLoc();
   if (isImmMskBitp(Value)) {
     int N = Log2_32(Value) + 1;
     return BuildMI(MBB, MI, dl, get(XCore::MKMSK_rus), Reg).addImm(N);
Index: llvm/trunk/test/CodeGen/XCore/dwarf_debug.ll
===================================================================
--- llvm/trunk/test/CodeGen/XCore/dwarf_debug.ll
+++ llvm/trunk/test/CodeGen/XCore/dwarf_debug.ll
@@ -0,0 +1,39 @@
+; RUN: llc < %s -march=xcore -O0 | FileCheck %s
+
+; target datalayout = "e-m:e-p:32:32-i1:8:32-i8:8:32-i16:16:32-i64:32-f64:32-a:0:32-n32"
+; target triple = "xcore"
+
+; CHECK-LABEL: f
+; CHECK: entsp 2
+; ...the prologue...
+; CHECK: .loc 1 2 0 prologue_end      # :2:0
+; CHECK: add r0, r0, 1
+; CHECK: retsp 2
+define i32 @f(i32 %a) {
+entry:
+  %a.addr = alloca i32, align 4
+  store i32 %a, i32* %a.addr, align 4
+  call void @llvm.dbg.declare(metadata !{i32* %a.addr}, metadata !11), !dbg !12
+  %0 = load i32* %a.addr, align 4, !dbg !12
+  %add = add nsw i32 %0, 1, !dbg !12
+  ret i32 %add, !dbg !12
+}
+
+declare void @llvm.dbg.declare(metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!9, !10}
+!0 = metadata !{i32 786449, metadata !1, i32 12, metadata !"", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !2, metadata !2, metadata !"", i32 1}
+!1 = metadata !{metadata !"", metadata !""}
+!2 = metadata !{}
+!3 = metadata !{metadata !4}
+!4 = metadata !{i32 786478, metadata !1, metadata !5, metadata !"f", metadata !"f", metadata !"", i32 2, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 (i32)* @f, null, null, metadata !2, i32 2}
+!5 = metadata !{i32 786473, metadata !1}
+!6 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !7, i32 0, null, null, null}
+!7 = metadata !{metadata !8, metadata !8}
+!8 = metadata !{i32 786468, null, null, metadata !"int", i32 0, i64 32, i64 32, i64 0, i32 0, i32 5}
+!9 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
+!10 = metadata !{i32 2, metadata !"Debug Info Version", i32 1}
+!11 = metadata !{i32 786689, metadata !4, metadata !"a", metadata !5, i32 16777218, metadata !8, i32 0, i32 0}
+!12 = metadata !{i32 2, i32 0, metadata !4, null}
+