Index: llvm/trunk/lib/Analysis/DependenceAnalysis.cpp
===================================================================
--- llvm/trunk/lib/Analysis/DependenceAnalysis.cpp
+++ llvm/trunk/lib/Analysis/DependenceAnalysis.cpp
@@ -2409,6 +2409,8 @@
           Constant = getConstantPart(Product);
         else
           Constant = cast<SCEVConstant>(Coeff);
+        if (!Constant)
+          return false;
         APInt ConstCoeff = Constant->getAPInt();
         RunningGCD = APIntOps::GreatestCommonDivisor(RunningGCD, ConstCoeff.abs());
       }
@@ -2427,6 +2429,8 @@
           Constant = getConstantPart(Product);
         else
           Constant = cast<SCEVConstant>(Coeff);
+        if (!Constant)
+          return false;
         APInt ConstCoeff = Constant->getAPInt();
         RunningGCD = APIntOps::GreatestCommonDivisor(RunningGCD, ConstCoeff.abs());
       }
@@ -2444,6 +2448,8 @@
       // or constant, in which case we give up on this direction.
       continue;
     }
+    if (!Constant)
+      continue;
     APInt ConstCoeff = Constant->getAPInt();
     RunningGCD = APIntOps::GreatestCommonDivisor(RunningGCD, ConstCoeff.abs());
     DEBUG(dbgs() << "\tRunningGCD = " << RunningGCD << "\n");
Index: llvm/trunk/test/Analysis/DependenceAnalysis/MIVCheckConst.ll
===================================================================
--- llvm/trunk/test/Analysis/DependenceAnalysis/MIVCheckConst.ll
+++ llvm/trunk/test/Analysis/DependenceAnalysis/MIVCheckConst.ll
@@ -0,0 +1,73 @@
+; RUN: opt < %s -analyze -basicaa -da
+
+; Test that the dependence analysis pass does seg-fault due to a null pointer
+; dereference. The code in gcdMIVTest requires a null check for the result of
+; getConstantPart.
+
+target datalayout = "e-m:e-p:32:32-i1:32-i64:64-a:0-v32:32-n16:32"
+
+%0 = type { i32 }
+%1 = type { [2 x [512 x %0]], [512 x %0], %2, [144 x i8], %9, %10, %11, %12, %17, [12 x i8], %18, %19, %21, [128 x i8] }
+%2 = type { [64 x i16], [64 x i16], [64 x %0], [64 x %0], [128 x %0], [128 x %0], [256 x %0], [256 x %0], [32 x %0], [32 x %0], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16], %3, %4, %5, [32 x i32], [32 x i32], [32 x i32], [32 x i32], [32 x i32], [32 x i32], %6, %7, [32 x i32], [32 x i32], [32 x i32], [64 x i16], %8, [8 x i64], [4 x i64], [2 x i64], [256 x i8], [256 x i32], [64 x i16], [64 x i16] }
+%3 = type { [64 x i32], [32 x i32], [32 x i32], [32 x i32], [32 x i32], [32 x i32], [32 x i32], [32 x i32], [32 x i32], [32 x i32], [32 x i32], [32 x i32], [32 x i32], [32 x i32], [32 x i32], [64 x i32], [64 x i32], [64 x i32], [64 x i32], [64 x i32], [64 x i32], [64 x i32], [64 x i32], [64 x i32], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [32 x %0], [32 x %0], [128 x i8] }
+%4 = type { [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16] }
+%5 = type { [128 x i8], [256 x i8], [256 x i8] }
+%6 = type { [64 x i32], [128 x i16], [64 x i16], [64 x i16], [64 x i16] }
+%7 = type { [192 x %0], [192 x %0], [384 x %0], [1984 x %0] }
+%8 = type { [128 x i8], [128 x i8], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16], [64 x i16] }
+%9 = type { [32 x %0], [32 x %0], [64 x i32], [64 x i32], [64 x i32], [64 x i32] }
+%10 = type { [1536 x %0], [2048 x %0], [512 x i32], [256 x i32], [32 x %0], [64 x i32], [128 x i8], [512 x i32], [1024 x %0] }
+%11 = type { [512 x i32], [512 x i32], [1024 x %0], [512 x i32], [512 x %0] }
+%12 = type { %13, [2048 x %0], [2048 x %0], [256 x i32], [1024 x i32], %14, [512 x %0], [256 x i32], %15, [4 x [256 x %0]], [4 x [256 x %0]], [256 x i32], [8 x [32 x i32]], [8 x [32 x %0]], [384 x %0], [256 x i32], %16 }
+%13 = type { [2048 x %0] }
+%14 = type { [1024 x %0], [1024 x %0] }
+%15 = type { [256 x %0], [256 x %0] }
+%16 = type { [128 x %0], [128 x %0] }
+%17 = type { [32 x %0], [32 x i32], [32 x i32], [32 x i32], [32 x i32], [2 x [8 x [32 x %0]]], [512 x %0], [512 x %0], [58 x i16] }
+%18 = type { [512 x i8] }
+%19 = type { [2048 x %0], [2560 x i16], %20, [512 x i32], [256 x i32], [512 x i8] }
+%20 = type { [768 x i32] }
+%21 = type { [416 x i32] }
+
+define void @test(%1* %A) #0 align 2 {
+entry:
+  %v1 = load i32, i32* undef, align 4
+  br label %bb13
+
+bb13:
+  %v2 = phi i32 [ undef, %entry ], [ %v39, %bb38 ]
+  br i1 undef, label %bb15, label %bb38
+
+bb15:
+  %v3 = mul nsw i32 %v2, undef
+  br label %bb17
+
+bb17:
+  br i1 undef, label %bb21, label %bb37
+
+bb21:
+  %v22 = add nsw i32 undef, 1
+  %v23 = add i32 %v22, %v3
+  %v24 = mul nsw i32 %v23, %v1
+  %v25 = getelementptr inbounds %1, %1* %A, i32 0, i32 7, i32 1, i32 %v24
+  %v26 = bitcast %0* %v25 to <32 x i32>*
+  %v27 = load <32 x i32>, <32 x i32>* %v26, align 256
+  %v28 = add i32 undef, %v3
+  %v29 = mul nsw i32 %v28, 32
+  %v30 = getelementptr inbounds %1, %1* %A, i32 0, i32 7, i32 14, i32 %v29
+  %v31 = bitcast %0* %v30 to <32 x i32>*
+  %v32 = load <32 x i32>, <32 x i32>* %v31, align 128
+  br i1 undef, label %bb21, label %bb37
+
+bb37:
+  br i1 undef, label %bb17, label %bb38
+
+bb38:
+  %v39 = add nsw i32 %v2, 1
+  br label %bb13
+
+bb40:
+  ret void
+}
+
+attributes #0 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }