From c1dc35094e3ffcb4b3a765f0f786b8a2948bc321 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Sat, 31 Oct 2009 20:13:24 +0000
Subject: [PATCH] adjust a couple xforms to work with null bb's in
 BlockAddress.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85680 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/IPO/GlobalOpt.cpp     | 3 +--
 lib/Transforms/Utils/ValueMapper.cpp | 9 +++++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/lib/Transforms/IPO/GlobalOpt.cpp b/lib/Transforms/IPO/GlobalOpt.cpp
index 49e9683a556..94951002b46 100644
--- a/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/lib/Transforms/IPO/GlobalOpt.cpp
@@ -2345,8 +2345,7 @@ static bool EvaluateFunction(Function *F, Constant *&RetVal,
         Value *Val = getVal(Values, IBI->getAddress())->stripPointerCasts();
         if (BlockAddress *BA = dyn_cast<BlockAddress>(Val))
           NewBB = BA->getBasicBlock();
-        else
-          return false;  // Cannot determine.
+        if (NewBB == 0) return false;  // Cannot determine.
       } else if (ReturnInst *RI = dyn_cast<ReturnInst>(CurInst)) {
         if (RI->getNumOperands())
           RetVal = getVal(Values, RI->getOperand(0));
diff --git a/lib/Transforms/Utils/ValueMapper.cpp b/lib/Transforms/Utils/ValueMapper.cpp
index 39331d78169..7929eb9ac2b 100644
--- a/lib/Transforms/Utils/ValueMapper.cpp
+++ b/lib/Transforms/Utils/ValueMapper.cpp
@@ -113,8 +113,13 @@ Value *llvm::MapValue(const Value *V, ValueMapTy &VM) {
   
   if (BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
     Function *F = cast<Function>(MapValue(BA->getFunction(), VM));
-    BasicBlock *BB = cast_or_null<BasicBlock>(MapValue(BA->getBasicBlock(),VM));
-    return VM[V] = BlockAddress::get(F, BB ? BB : BA->getBasicBlock());
+    BasicBlock *BB = 0;
+    if (BA->getBasicBlock()) {
+      BB = cast_or_null<BasicBlock>(MapValue(BA->getBasicBlock(),VM));
+      BB = BB ? BB : BA->getBasicBlock();
+    }
+    
+    return VM[V] = BlockAddress::get(F, BB);
   }
   
   llvm_unreachable("Unknown type of constant!");