From ef562471cebd643288a19fca1ece8c52e70ceff0 Mon Sep 17 00:00:00 2001
From: Owen Anderson <resistor@mac.com>
Date: Mon, 18 Feb 2008 10:11:00 +0000
Subject: [PATCH] Since we're not checking for the more general AllocationInst
 first, we need to explicitly check that Object is an Argument before casting
 it to one.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47268 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/BasicAliasAnalysis.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 5124376a98a..fa5c5b894c8 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -272,7 +272,7 @@ BasicAliasAnalysis::getModRefInfo(CallSite CS, Value *P, unsigned Size) {
       // If this is a tail call and P points to a stack location, we know that
       // the tail call cannot access or modify the local stack.
       if (isa<AllocaInst>(Object) ||
-          cast<Argument>(Object)->hasByValAttr())
+          (isa<Argument>(Object) && cast<Argument>(Object)->hasByValAttr()))
         if (CallInst *CI = dyn_cast<CallInst>(CS.getInstruction()))
           if (CI->isTailCall())
             return NoModRef;