diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 2020415..8c2dc3e 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -9131,6 +9131,10 @@
           CI.setOperand(0, Intrinsic::getDeclaration(M, MemCpyID));
           Changed = true;
         }
+
+      // memmove(x,x,size) -> noop.
+      if (MMI->getSource() == MMI->getDest())
+        return EraseInstFromFunction(CI);
     }
 
     // If we can determine a pointer alignment that is bigger than currently
diff --git a/test/Transforms/InstCombine/memmove.ll b/test/Transforms/InstCombine/memmove.ll
index 2cb346f..09ec67d 100644
--- a/test/Transforms/InstCombine/memmove.ll
+++ b/test/Transforms/InstCombine/memmove.ll
@@ -34,3 +34,9 @@
 	ret i32 0
 }
 
+; PR2370
+define void @test4(i8* %a) {
+        tail call void @llvm.memmove.i32( i8* %a, i8* %a, i32 100, i32 1 )
+        ret void
+}
+