diff --git a/lib/Transforms/Scalar/CodeGenPrepare.cpp b/lib/Transforms/Scalar/CodeGenPrepare.cpp
index 78568639539..305d70f27b0 100644
--- a/lib/Transforms/Scalar/CodeGenPrepare.cpp
+++ b/lib/Transforms/Scalar/CodeGenPrepare.cpp
@@ -226,7 +226,8 @@ bool CodeGenPrepare::EliminateFallThrough(Function &F) {
     // edge, just collapse it.
     BasicBlock *SinglePred = BB->getSinglePredecessor();
 
-    if (!SinglePred || SinglePred == BB) continue;
+    // Don't merge if BB's address is taken.
+    if (!SinglePred || SinglePred == BB || BB->hasAddressTaken()) continue;
 
     BranchInst *Term = dyn_cast<BranchInst>(SinglePred->getTerminator());
     if (Term && !Term->isConditional()) {
@@ -788,7 +789,7 @@ bool CodeGenPrepare::DupRetToEnableTailCallOpts(ReturnInst *RI) {
   }
 
   // If we eliminated all predecessors of the block, delete the block now.
-  if (Changed && pred_begin(BB) == pred_end(BB))
+  if (Changed && !BB->hasAddressTaken() && pred_begin(BB) == pred_end(BB))
     BB->eraseFromParent();
 
   return Changed;
diff --git a/test/CodeGen/X86/2012-09-28-CGPBug.ll b/test/CodeGen/X86/2012-09-28-CGPBug.ll
new file mode 100644
index 00000000000..32d7d012dd1
--- /dev/null
+++ b/test/CodeGen/X86/2012-09-28-CGPBug.ll
@@ -0,0 +1,53 @@
+; RUN: llc -mtriple=i386-apple-macosx < %s | FileCheck %s
+; rdar://12396696
+
+@JT = global [4 x i32] [i32 sub (i32 ptrtoint (i8* blockaddress(@h, %18) to i32), i32 ptrtoint (i8* blockaddress(@h, %11) to i32)), i32 sub (i32 ptrtoint (i8* blockaddress(@h, %17) to i32), i32 ptrtoint (i8* blockaddress(@h, %11) to i32)), i32 sub (i32 ptrtoint (i8* blockaddress(@h, %22) to i32), i32 ptrtoint (i8* blockaddress(@h, %18) to i32)), i32 sub (i32 ptrtoint (i8* blockaddress(@h, %22) to i32), i32 ptrtoint (i8* blockaddress(@h, %17) to i32))]
+@gGlobalLock = external global i8*
+@.str40 = external global [35 x i8]
+
+; CHECK: _JT:
+; CHECK-NOT: .long Ltmp{{[0-9]+}}-1
+; CHECK-NOT: .long 1-Ltmp{{[0-9]+}}
+; CHECK: .long Ltmp{{[0-9]+}}-Ltmp{{[0-9]+}}
+; CHECK: .long Ltmp{{[0-9]+}}-Ltmp{{[0-9]+}}
+; CHECK: .long Ltmp{{[0-9]+}}-Ltmp{{[0-9]+}}
+; CHECK: .long Ltmp{{[0-9]+}}-Ltmp{{[0-9]+}}
+
+define void @h(i8*) nounwind ssp {
+  %2 = alloca i8*
+  store i8* %0, i8** %2
+  %3 = load i8** %2
+  %4 = bitcast i8* %3 to { i32, i32 }*
+  %5 = getelementptr { i32, i32 }* %4, i32 0, i32 0
+  %6 = load i32* %5
+  %7 = srem i32 %6, 2
+  %8 = icmp slt i32 %6, 2
+  %9 = select i1 %8, i32 %6, i32 %7
+  %10 = icmp eq i32 %9, 0
+  br label %11
+
+; <label>:11                                      ; preds = %1
+  %12 = zext i1 %10 to i32
+  %13 = getelementptr [4 x i32]* @JT, i32 0, i32 %12
+  %14 = load i32* %13
+  %15 = add i32 %14, ptrtoint (i8* blockaddress(@h, %11) to i32)
+  %16 = inttoptr i32 %15 to i8*
+  indirectbr i8* %16, [label %17, label %18]
+
+; <label>:17                                      ; preds = %11
+  tail call void (i8*, ...)* @g(i8* getelementptr inbounds ([35 x i8]* @.str40, i32 0, i32 0))
+  br label %22
+
+; <label>:18                                      ; preds = %11
+  %19 = call i32 @f(i32 -1037694186) nounwind
+  %20 = inttoptr i32 %19 to i32 (i8**)*
+  %21 = tail call i32 %20(i8** @gGlobalLock)
+  br label %22
+
+; <label>:22                                      ; preds = %18, %17
+  ret void
+}
+
+declare i32 @f(i32)
+
+declare void @g(i8*, ...)