Index: llvm/trunk/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp
===================================================================
--- llvm/trunk/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp
+++ llvm/trunk/lib/Transforms/Scalar/SeparateConstOffsetFromGEP.cpp
@@ -824,8 +824,8 @@
   // If we created a GEP with constant index, and the base is loop invariant,
   // then we swap the first one with it, so LICM can move constant GEP out
   // later.
-  GetElementPtrInst *FirstGEP = dyn_cast<GetElementPtrInst>(FirstResult);
-  GetElementPtrInst *SecondGEP = dyn_cast<GetElementPtrInst>(ResultPtr);
+  GetElementPtrInst *FirstGEP = dyn_cast_or_null<GetElementPtrInst>(FirstResult);
+  GetElementPtrInst *SecondGEP = dyn_cast_or_null<GetElementPtrInst>(ResultPtr);
   if (isSwapCandidate && isLegalToSwapOperand(FirstGEP, SecondGEP, L))
     swapGEPOperand(FirstGEP, SecondGEP);
 
Index: llvm/trunk/test/CodeGen/AArch64/gep-nullptr.ll
===================================================================
--- llvm/trunk/test/CodeGen/AArch64/gep-nullptr.ll
+++ llvm/trunk/test/CodeGen/AArch64/gep-nullptr.ll
@@ -0,0 +1,23 @@
+; RUN: llc -O3 -aarch64-gep-opt=true   < %s |FileCheck %s
+target datalayout = "e-m:e-i64:64-i128:128-n8:16:32:64-S128"
+target triple = "aarch64--linux-gnu"
+
+%structA = type { i8, i8, i8, i8, i8, i8, [4 x i8], i8, i8, [2 x i32], [2 x %unionMV], [4 x [2 x %unionMV]], [4 x [2 x %unionMV]], [4 x i8], i8*, i8*, i32, i8* }
+%unionMV = type { i32 }
+
+; Function Attrs: nounwind
+define void @test(%structA* %mi_block) {
+entry:
+  br i1 undef, label %for.body13.us, label %if.else
+
+; Just make sure we don't get a compiler ICE due to dereferncing a nullptr.
+; CHECK-LABEL: test
+for.body13.us:                                    ; preds = %entry
+  %indvars.iv.next40 = or i64 0, 1
+  %packed4.i.us.1 = getelementptr inbounds %structA, %structA* %mi_block, i64 0, i32 11, i64 0, i64 %indvars.iv.next40, i32 0
+  unreachable
+
+if.else:                                          ; preds = %entry
+  ret void
+}
+