Tpetra::Vector: Fix deprecated warning (Issue #104)

@trilinos/tpetra Vector::normWeighted is deprecated.  It calls its
parent class' method MultiVector::normWeighted, which is also
deprecated.  Even though nothing calls Vector::normWeighted any more,
some compilers still emit a deprecated warning when building it, because
it calls a deprecated method.  This breaks builds that turn on warnings
as errors, and also adds useless noise to the build output.

This commit reimplements Vector::normWeighted so that it doesn't call
MultiVector::normWeighted.  This should fix Issue #104.

Build/Test Cases Summary
Enabled Packages: TpetraCore
Disabled Packages: FEI,STK,PyTrilinos,NOX,Teko,Piro
0) MPI_DEBUG => Test case MPI_DEBUG was not run! => Does not affect push readiness! (-1.00 min)
1) SERIAL_RELEASE => Test case SERIAL_RELEASE was not run! => Does not affect push readiness! (-1.00 min)
2) MPI_DEBUG_COMPLEX => passed: passed=85,notpassed=0 (7.06 min)
3) SERIAL_RELEASE => passed: passed=65,notpassed=0 (9.08 min)

packages/tpetra/core/src/Tpetra_Vector_def.hpp

@@ -52,6 +52,7 @@
 
 #include "Tpetra_MultiVector.hpp"
 #include "KokkosCompat_View.hpp"
+#include "Kokkos_Blas1_MV.hpp"
 
 namespace Tpetra {
 
@@ -200,9 +201,56 @@ namespace Tpetra {
   Vector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>::
   normWeighted (const Vector<Scalar, LocalOrdinal, GlobalOrdinal, Node, classic>& weights) const
   {
-    mag_type norm;
-    this->normWeighted (weights, Teuchos::arrayView (&norm, 1));
-    return norm;
+    using Kokkos::ALL;
+    using Kokkos::subview;
+    using Teuchos::Comm;
+    using Teuchos::RCP;
+    using Teuchos::reduceAll;
+    using Teuchos::REDUCE_SUM;
+    typedef Kokkos::Details::ArithTraits<impl_scalar_type> ATS;
+    typedef Kokkos::Details::ArithTraits<mag_type> ATM;
+    typedef Kokkos::View<mag_type, device_type> norm_view_type; // just one
+    const char tfecfFuncName[] = "normWeighted: ";
+
+#ifdef HAVE_TPETRA_DEBUG
+    TEUCHOS_TEST_FOR_EXCEPTION_CLASS_FUNC(
+      ! this->getMap ()->isCompatible (*weights.getMap ()), std::runtime_error,
+      "Vectors do not have compatible Maps:" << std::endl
+      << "this->getMap(): " << std::endl << *this->getMap()
+      << "weights.getMap(): " << std::endl << *weights.getMap() << std::endl);
+#else
+    const size_t lclNumRows = this->getLocalLength ();
+    TEUCHOS_TEST_FOR_EXCEPTION_CLASS_FUNC(
+      lclNumRows != weights.getLocalLength (), std::runtime_error,
+      "Vectors do not have the same local length.");
+#endif // HAVE_TPETRA_DEBUG
+
+    norm_view_type lclNrm ("lclNrm"); // local norm
+    mag_type gblNrm = ATM::zero (); // return value
+
+    auto X_lcl = this->template getLocalView<device_type> ();
+    auto W_lcl = this->template getLocalView<device_type> ();
+    KokkosBlas::nrm2w_squared (lclNrm,
+                               subview (X_lcl, ALL (), 0),
+                               subview (W_lcl, ALL (), 0));
+    const mag_type OneOverN =
+      ATM::one () / static_cast<mag_type> (this->getGlobalLength ());
+    RCP<const Comm<int> > comm = this->getMap ().is_null () ?
+      Teuchos::null : this->getMap ()->getComm ();
+
+    if (! comm.is_null () && this->isDistributed ()) {
+      // Assume that MPI can access device memory.
+      reduceAll<int, mag_type> (*comm, REDUCE_SUM, 1, lclNrm.ptr_on_device (),
+                                &gblNrm);
+      gblNrm = ATM::sqrt (gblNrm * OneOverN);
+    }
+    else {
+      auto lclNrm_h = Kokkos::create_mirror_view (lclNrm);
+      Kokkos::deep_copy (lclNrm_h, lclNrm);
+      gblNrm = ATM::sqrt (ATS::magnitude (lclNrm_h()) * OneOverN);
+    }
+
+    return gblNrm;
   }
 
   template <class Scalar, class LocalOrdinal, class GlobalOrdinal, class Node, const bool classic>