Do not consider debug intrinsics in the size computations for loop unrolling.

Patch contributed by Michael McCracken!

llvm-svn: 18108

llvm/lib/Transforms/Scalar/LoopUnroll.cpp

@@ -28,6 +28,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/STLExtras.h"
+#include "llvm/IntrinsicInst.h"
 #include <cstdio>
 #include <set>
 #include <algorithm>
@@ -86,6 +87,8 @@ static unsigned ApproximateLoopSize(const Loop *L) {
         // Ignore PHI nodes in the header.
       } else if (I->hasOneUse() && I->use_back() == Term) {
         // Ignore instructions only used by the loop terminator.
+      } else if (DbgInfoIntrinsic *DbgI = dyn_cast<DbgInfoIntrinsic>(I)) {
+	// Ignore debug instructions 
       } else {
         ++Size;
       }