Fix Regression/Transforms/LoopUnswitch/2006-02-22-UnswitchCrash.ll, which

caused SPASS to fail building last night.

We can't trivially unswitch a loop if the exit block has phi nodes in it,
because we don't know which predecessor to use.

llvm-svn: 26320

llvm/lib/Transforms/Scalar/LoopUnswitch.cpp

@@ -325,7 +325,9 @@ static bool IsTrivialUnswitchCondition(Loop *L, Value *Cond, Constant **Val = 0,
       }
   }
 
-  if (!LoopExitBB)
+  // If we didn't find a single unique LoopExit block, or if the loop exit block
+  // contains phi nodes, this isn't trivial.
+  if (!LoopExitBB || isa<PHINode>(LoopExitBB->begin()))
     return false;   // Can't handle this.
   
   if (LoopExit) *LoopExit = LoopExitBB;