diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index 3f124c00406..acbc911d6ac 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -1655,6 +1655,8 @@ SimpleRegisterCoalescing::TurnCopyIntoImpDef(MachineBasicBlock::iterator &I,
   LiveInterval &SrcInt = li_->getInterval(SrcReg);
   if (!SrcInt.empty())
     return false;
+  if (!li_->hasInterval(DstReg))
+    return false;
   LiveInterval &DstInt = li_->getInterval(DstReg);
   LiveInterval::iterator DstLR = DstInt.FindLiveRangeContaining(CopyIdx);
   DstInt.removeValNo(DstLR->valno);
diff --git a/test/CodeGen/X86/2008-04-08-CoalescerCrash.ll b/test/CodeGen/X86/2008-04-08-CoalescerCrash.ll
new file mode 100644
index 00000000000..f5de113b9ea
--- /dev/null
+++ b/test/CodeGen/X86/2008-04-08-CoalescerCrash.ll
@@ -0,0 +1,19 @@
+; RUN: llvm-as < %s | llc -march=x86 -mattr=+mmx
+
+define i32 @t2() nounwind  {
+entry:
+	tail call void asm sideeffect "# top of block", "~{dirflag},~{fpsr},~{flags},~{di},~{si},~{dx},~{cx},~{ax}"( ) nounwind 
+	tail call void asm sideeffect ".file \224443946.c\22", "~{dirflag},~{fpsr},~{flags}"( ) nounwind 
+	tail call void asm sideeffect ".line 8", "~{dirflag},~{fpsr},~{flags}"( ) nounwind 
+	%tmp1 = tail call <2 x i32> asm sideeffect "movd $1, $0", "=={mm4},{bp},~{dirflag},~{fpsr},~{flags},~{memory}"( i32 undef ) nounwind 		; <<2 x i32>> [#uses=1]
+	tail call void asm sideeffect ".file \224443946.c\22", "~{dirflag},~{fpsr},~{flags}"( ) nounwind 
+	tail call void asm sideeffect ".line 9", "~{dirflag},~{fpsr},~{flags}"( ) nounwind 
+	%tmp3 = tail call i32 asm sideeffect "movd $1, $0", "=={bp},{mm3},~{dirflag},~{fpsr},~{flags},~{memory}"( <2 x i32> undef ) nounwind 		; <i32> [#uses=1]
+	tail call void asm sideeffect ".file \224443946.c\22", "~{dirflag},~{fpsr},~{flags}"( ) nounwind 
+	tail call void asm sideeffect ".line 10", "~{dirflag},~{fpsr},~{flags}"( ) nounwind 
+	tail call void asm sideeffect "movntq $0, 0($1,$2)", "{mm0},{di},{bp},~{dirflag},~{fpsr},~{flags},~{memory}"( <2 x i32> undef, i32 undef, i32 %tmp3 ) nounwind 
+	tail call void asm sideeffect ".file \224443946.c\22", "~{dirflag},~{fpsr},~{flags}"( ) nounwind 
+	tail call void asm sideeffect ".line 11", "~{dirflag},~{fpsr},~{flags}"( ) nounwind 
+	%tmp8 = tail call i32 asm sideeffect "movd $1, $0", "=={bp},{mm4},~{dirflag},~{fpsr},~{flags},~{memory}"( <2 x i32> %tmp1 ) nounwind 		; <i32> [#uses=0]
+	ret i32 undef
+}