Check whether a pointer is non-null (isKnownNonNull) in isKnownNonZero.

This handles the case where we have an inbounds GEP with alloca as the pointer.
This fixes the regression in PR12750 and rdar://13286434.
Note that we can also fix this by handling some GEP cases in isKnownNonNull.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177321 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index 45b75df..45dcc5e3 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -953,6 +953,8 @@
 
   // Check for pointer simplifications.
   if (V->getType()->isPointerTy()) {
+    if (isKnownNonNull(V))
+      return true; 
     if (GEPOperator *GEP = dyn_cast<GEPOperator>(V))
       if (isGEPKnownNonNull(GEP, TD, Depth))
         return true;