From fcda998ab2f44aa1f8015b3e8084de3a442d7a9e Mon Sep 17 00:00:00 2001
From: Devang Patel <dpatel@apple.com>
Date: Tue, 18 Sep 2007 01:54:42 +0000
Subject: Fix PR1657

llvm-svn: 42075
---
 llvm/lib/Transforms/Scalar/LICM.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

(limited to 'llvm/lib/Transforms')

diff --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp
index ac927da07e3..6c5976ad3a9 100644
--- a/llvm/lib/Transforms/Scalar/LICM.cpp
+++ b/llvm/lib/Transforms/Scalar/LICM.cpp
@@ -791,6 +791,14 @@ void LICM::FindPromotableValuesInLoop(
           break;
         }
 
+      // If GEP base is NULL then the calculated address  used by Store or
+      // Load instruction is invalid. Do not promote this value because
+      // it may expose load and store instruction that are covered by
+      // condition which may not yet folded.
+      if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V))
+        if (isa<ConstantPointerNull>(GEP->getOperand(0)))
+          PointerOk = false;
+
       if (PointerOk) {
         const Type *Ty = cast<PointerType>(V->getType())->getElementType();
         AllocaInst *AI = new AllocaInst(Ty, 0, V->getName()+".tmp", FnStart);
-- 
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