InstCombine: Harden code to work with vectors of pointers and simplify it a bit.

Found by running instcombine on a fabricated test case for the constant folder.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174430 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp
index 653f97a..230dc28 100644
--- a/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -1395,17 +1395,13 @@
   // If the destination integer type is not the intptr_t type for this target,
   // do a ptrtoint to intptr_t then do a trunc or zext.  This allows the cast
   // to be exposed to other transforms.
-  if (TD) {
-    if (CI.getType()->getScalarSizeInBits() < TD->getPointerSizeInBits()) {
-      Value *P = Builder->CreatePtrToInt(CI.getOperand(0),
-                                         TD->getIntPtrType(CI.getContext()));
-      return new TruncInst(P, CI.getType());
-    }
-    if (CI.getType()->getScalarSizeInBits() > TD->getPointerSizeInBits()) {
-      Value *P = Builder->CreatePtrToInt(CI.getOperand(0),
-                                         TD->getIntPtrType(CI.getContext()));
-      return new ZExtInst(P, CI.getType());
-    }
+  if (TD && CI.getType()->getScalarSizeInBits() != TD->getPointerSizeInBits()) {
+    Type *Ty = TD->getIntPtrType(CI.getContext());
+    if (CI.getType()->isVectorTy()) // Handle vectors of pointers.
+      Ty = VectorType::get(Ty, CI.getType()->getVectorNumElements());
+
+    Value *P = Builder->CreatePtrToInt(CI.getOperand(0), Ty);
+    return CastInst::CreateIntegerCast(P, CI.getType(), /*isSigned=*/false);
   }
 
   return commonPointerCastTransforms(CI);