Index: lib/Analysis/ConstantFolding.cpp
===================================================================
--- lib/Analysis/ConstantFolding.cpp
+++ lib/Analysis/ConstantFolding.cpp
@@ -55,7 +55,8 @@
   // Catch the obvious splat cases.
   if (C->isNullValue() && !DestTy->isX86_MMXTy())
     return Constant::getNullValue(DestTy);
-  if (C->isAllOnesValue() && !DestTy->isX86_MMXTy())
+  if (C->isAllOnesValue() && !DestTy->isX86_MMXTy() &&
+      !DestTy->isPtrOrPtrVectorTy()) // don't get ones for ptr types!
     return Constant::getAllOnesValue(DestTy);
 
   // Handle a vector->integer cast.
@@ -195,9 +196,12 @@
     return ConstantVector::get(Result);
   }
 
-  // Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>)
+  // Handle: bitcast (<2 x i64> <i64 0, i64 1> to <4 x i32>) and
+  //         bitcast (<1 x i128> <i128 -1> to <2 x i8*>)
+  bool IsDstEltTyPtr = DstEltTy->isPointerTy();
   unsigned Ratio = NumDstElt/NumSrcElt;
-  unsigned DstBitSize = DstEltTy->getPrimitiveSizeInBits();
+  unsigned DstBitSize = IsDstEltTyPtr ? TD.getPointerTypeSizeInBits(DstEltTy)
+                                      : DstEltTy->getPrimitiveSizeInBits();
 
   // Loop over each source value, expanding into multiple results.
   for (unsigned i = 0; i != NumSrcElt; ++i) {
@@ -213,6 +217,15 @@
                                   ConstantInt::get(Src->getType(), ShiftAmt));
       ShiftAmt += isLittleEndian ? DstBitSize : -DstBitSize;
 
+      // Truncate the element to an integer with the same pointer size and
+      // convert the element back to a pointer using a inttoptr.
+      if (IsDstEltTyPtr) {
+        IntegerType *DstIntTy = Type::getIntNTy(C->getContext(), DstBitSize);
+        Constant *CE = ConstantExpr::getTrunc(Elt, DstIntTy);
+        Result.push_back(ConstantExpr::getIntToPtr(CE, DstEltTy));
+        continue;
+      }
+
       // Truncate and remember this piece.
       Result.push_back(ConstantExpr::getTrunc(Elt, DstEltTy));
     }
Index: test/Transforms/InstSimplify/vector_ptr_bitcast.ll
===================================================================
--- /dev/null
+++ test/Transforms/InstSimplify/vector_ptr_bitcast.ll
@@ -0,0 +1,17 @@
+; RUN: opt -S -instsimplify < %s | FileCheck %s
+target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128"
+
+%mst = type { i8*, i8* }
+
+@a = private unnamed_addr constant %mst { i8* inttoptr (i64 -1 to i8*),
+                                          i8* inttoptr (i64 -1 to i8*)},
+                                          align 8
+
+define void @fn() {
+  %x = load <2 x i8*>* bitcast (%mst* @a to <2 x i8*>*), align 8
+  %b = extractelement <2 x i8*> %x, i32 0
+  ; CHECK-LABEL: @fn
+  ; CHECK-NEXT: ret void
+  ret void
+}
+