diff --git a/lib/CodeGen/RegisterScavenging.cpp b/lib/CodeGen/RegisterScavenging.cpp
index d34b701db94..179984f2a99 100644
--- a/lib/CodeGen/RegisterScavenging.cpp
+++ b/lib/CodeGen/RegisterScavenging.cpp
@@ -136,6 +136,9 @@ void RegScavenger::forward() {
     ScavengeRestore = NULL;
   }
 
+  if (MI->isDebugValue())
+    return;
+
   // Find out which registers are early clobbered, killed, defined, and marked
   // def-dead in this instruction.
   BitVector EarlyClobberRegs(NumPhysRegs);
diff --git a/test/CodeGen/ARM/2010-04-15-ScavengerDebugValue.ll b/test/CodeGen/ARM/2010-04-15-ScavengerDebugValue.ll
new file mode 100644
index 00000000000..ed7bca8510d
--- /dev/null
+++ b/test/CodeGen/ARM/2010-04-15-ScavengerDebugValue.ll
@@ -0,0 +1,26 @@
+; RUN: llc < %s
+; PR6847
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:32-f32:32:32-f64:32:32-v64:64:64-v128:128:128-a0:0:64-n32"
+target triple = "armv4t-apple-darwin10"
+
+define hidden arm_apcscc i32 @__addvsi3(i32 %a, i32 %b) nounwind {
+entry:
+  tail call void @llvm.dbg.value(metadata !{i32 %b}, i64 0, metadata !0)
+  %0 = add nsw i32 %b, %a, !dbg !9                ; <i32> [#uses=1]
+  ret i32 %0, !dbg !11
+}
+
+declare void @llvm.dbg.value(metadata, i64, metadata) nounwind readnone
+
+!0 = metadata !{i32 524545, metadata !1, metadata !"b", metadata !2, i32 93, metadata !6} ; [ DW_TAG_arg_variable ]
+!1 = metadata !{i32 524334, i32 0, metadata !2, metadata !"__addvsi3", metadata !"__addvsi3", metadata !"__addvsi3", metadata !2, i32 94, metadata !4, i1 false, i1 true, i32 0, i32 0, null, i1 false} ; [ DW_TAG_subprogram ]
+!2 = metadata !{i32 524329, metadata !"libgcc2.c", metadata !"/Users/bwilson/local/nightly/test-2010-04-14/build/llvmgcc.roots/llvmgcc~obj/src/gcc", metadata !3} ; [ DW_TAG_file_type ]
+!3 = metadata !{i32 524305, i32 0, i32 1, metadata !"libgcc2.c", metadata !"/Users/bwilson/local/nightly/test-2010-04-14/build/llvmgcc.roots/llvmgcc~obj/src/gcc", metadata !"4.2.1 (Based on Apple Inc. build 5658) (LLVM build 00)", i1 true, i1 true, metadata !"", i32 0} ; [ DW_TAG_compile_unit ]
+!4 = metadata !{i32 524309, metadata !2, metadata !"", metadata !2, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !5, i32 0, null} ; [ DW_TAG_subroutine_type ]
+!5 = metadata !{metadata !6, metadata !6, metadata !6}
+!6 = metadata !{i32 524310, metadata !2, metadata !"SItype", metadata !7, i32 152, i64 0, i64 0, i64 0, i32 0, metadata !8} ; [ DW_TAG_typedef ]
+!7 = metadata !{i32 524329, metadata !"libgcc2.h", metadata !"/Users/bwilson/local/nightly/test-2010-04-14/build/llvmgcc.roots/llvmgcc~obj/src/gcc", metadata !3} ; [ DW_TAG_file_type ]
+!8 = metadata !{i32 524324, metadata !2, metadata !"int", metadata !2, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
+!9 = metadata !{i32 95, i32 0, metadata !10, null}
+!10 = metadata !{i32 524299, metadata !1, i32 94, i32 0} ; [ DW_TAG_lexical_block ]
+!11 = metadata !{i32 100, i32 0, metadata !10, null}