diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 6aeaec2..d13a333 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -753,9 +753,8 @@
           //
           if (const ArrayType *AT = dyn_cast<ArrayType>(BasePtr1Ty))
             GEP1Ops[i] = ConstantInt::get(Type::Int64Ty,AT->getNumElements()-1);
-          else if (const VectorType *PT = dyn_cast<VectorType>(BasePtr1Ty))
-            GEP1Ops[i] = ConstantInt::get(Type::Int64Ty,PT->getNumElements()-1);
-
+          else if (const VectorType *VT = dyn_cast<VectorType>(BasePtr1Ty))
+            GEP1Ops[i] = ConstantInt::get(Type::Int64Ty,VT->getNumElements()-1);
         }
       }
 
@@ -765,8 +764,8 @@
           if (const ArrayType *AT = dyn_cast<ArrayType>(BasePtr1Ty)) {
             if (Op2C->getZExtValue() >= AT->getNumElements())
               return MayAlias;  // Be conservative with out-of-range accesses
-          } else if (const VectorType *PT = dyn_cast<VectorType>(BasePtr1Ty)) {
-            if (Op2C->getZExtValue() >= PT->getNumElements())
+          } else if (const VectorType *VT = dyn_cast<VectorType>(BasePtr1Ty)) {
+            if (Op2C->getZExtValue() >= VT->getNumElements())
               return MayAlias;  // Be conservative with out-of-range accesses
           }
         } else {  // Conservatively assume the minimum value for this index
@@ -795,8 +794,13 @@
       getTargetData().getIndexedOffset(GEPPointerTy, GEP1Ops, NumGEP1Ops);
     int64_t Offset2 = 
       getTargetData().getIndexedOffset(GEPPointerTy, GEP2Ops, NumGEP2Ops);
-    assert(Offset1<Offset2 && "There is at least one different constant here!");
-
+    assert(Offset1 != Offset2 &&
+           "There is at least one different constant here!");
+    
+    // Make sure we compare the absolute difference.
+    if (Offset1 > Offset2)
+      std::swap(Offset1, Offset2);
+    
     if ((uint64_t)(Offset2-Offset1) >= SizeMax) {
       //cerr << "Determined that these two GEP's don't alias ["
       //     << SizeMax << " bytes]: \n" << *GEP1 << *GEP2;
diff --git a/test/Analysis/BasicAA/2007-11-05-SizeCrash.ll b/test/Analysis/BasicAA/2007-11-05-SizeCrash.ll
new file mode 100644
index 0000000..5a938cf
--- /dev/null
+++ b/test/Analysis/BasicAA/2007-11-05-SizeCrash.ll
@@ -0,0 +1,34 @@
+; RUN: llvm-as < %s | opt -gvn -disable-output
+; PR1774
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128"
+target triple = "x86_64-unknown-linux-gnu"
+        %struct.device = type { [20 x i8] }
+        %struct.pci_device_id = type { i32, i32, i32, i32, i32, i32, i64 }
+        %struct.usb_bus = type { %struct.device* }
+        %struct.usb_hcd = type { %struct.usb_bus, i64, [0 x i64] }
+@uhci_pci_ids = external constant [1 x %struct.pci_device_id]           ; <[1 x %struct.pci_device_id]*> [#uses=1]
+
+@__mod_pci_device_table = alias [1 x %struct.pci_device_id]* @uhci_pci_ids     
+        ; <[1 x %struct.pci_device_id]*> [#uses=0]
+
+define i32 @uhci_suspend(%struct.usb_hcd* %hcd) {
+entry:
+        %tmp17 = getelementptr %struct.usb_hcd* %hcd, i32 0, i32 2, i64 1      
+        ; <i64*> [#uses=1]
+        %tmp1718 = bitcast i64* %tmp17 to i32*          ; <i32*> [#uses=1]
+        %tmp19 = load i32* %tmp1718, align 4            ; <i32> [#uses=0]
+        br i1 false, label %cond_true34, label %done_okay
+
+cond_true34:            ; preds = %entry
+        %tmp631 = getelementptr %struct.usb_hcd* %hcd, i32 0, i32 2, i64
+2305843009213693950            ; <i64*> [#uses=1]
+        %tmp70 = bitcast i64* %tmp631 to %struct.device**               ;
+
+        %tmp71 = load %struct.device** %tmp70, align 8          ;
+
+        ret i32 undef
+
+done_okay:              ; preds = %entry
+        ret i32 undef
+}