We know it's always a SCEVConstant if it gets here, so just cast it and
inline the only use of isNegative. Fixes warning reported by Mike Stump.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61600 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index 375ad5e..b73eeab 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -2905,11 +2905,6 @@
   return false;
 }
 
-static bool isNegative(SCEVHandle X) {
-  if (SCEVConstant *C = dyn_cast<SCEVConstant>(X))
-    return C->getValue()->getValue().isNegative();
-}
-
 /// potentialInfiniteLoop - Test whether the loop might jump over the exit value
 /// due to wrapping around 2^n.
 bool ScalarEvolutionsImpl::potentialInfiniteLoop(SCEV *Stride, SCEV *RHS,
@@ -2967,7 +2962,8 @@
     // the stride is negative, we're not counting how many times 'less-than' is
     // true as we approach it, we're counting how far away we are from wrapping
     // around the backside.
-    if (isSigned && isNegative(Stride))
+    if (isSigned &&
+        cast<SCEVConstant>(Stride)->getValue()->getValue().isNegative())
       return UnknownValue;
 
     // We know the LHS is of the form {n,+,s} and the RHS is some loop-invariant