[Unroll] When completely unrolling the loop, replace conditinal branches with unconditional.

Nothing is expected to change, except we do less redundant work in
clean-up.

Reviewers: hfinkel

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12951

llvm-svn: 248444

lib/Transforms/Utils/LoopUnroll.cpp

@@ -434,8 +434,9 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount,
 
     // For a complete unroll, make the last iteration end with a branch
     // to the exit block.
-    if (CompletelyUnroll && j == 0) {
-      Dest = LoopExit;
+    if (CompletelyUnroll) {
+      if (j == 0)
+        Dest = LoopExit;
       NeedConditional = false;
     }