Alternative Skip Value Check (GridTools#1721)

This alternative check drastically improves performance when using NVCC (due to compiler better recognizing optimization potential).
Further, provides up-to-date performance references and an updated update_references.sh as the Jenkins setup now requires authentication to access the performance results.

include/gridtools/fn/unstructured.hpp

@@ -84,7 +84,7 @@ namespace gridtools::fn {
         template <class Tag, class Ptr, class Strides, class Domain, class Conn, class Offset>
         GT_FUNCTION constexpr auto horizontal_shift(iterator<Tag, Ptr, Strides, Domain> const &it, Conn, Offset) {
             auto const &table = host_device::at_key<Conn>(it.m_domain.m_tables);
-            auto new_index = get<Offset::value>(neighbor_table::neighbors(table, it.m_index));
+            auto new_index = it.m_index == -1 ? -1 : get<Offset::value>(neighbor_table::neighbors(table, it.m_index));
             auto shifted = it;
             shifted.m_index = new_index;
             return shifted;
@@ -101,9 +101,6 @@ namespace gridtools::fn {
         template <class Tag, class Ptr, class Strides, class Domain, class Dim, class Offset, class... Offsets>
         GT_FUNCTION constexpr auto shift(
             iterator<Tag, Ptr, Strides, Domain> const &it, Dim, Offset offset, Offsets... offsets) {
-            if (it.m_index == -1)
-                return it;
-
             if constexpr (has_key<decltype(it.m_domain.m_tables), Dim>()) {
                 return shift(horizontal_shift(it, Dim(), offset), offsets...);
             } else {

jenkins/update_references.sh

@@ -5,16 +5,21 @@ if [[ -z $1 ]]; then
     exit 1
 fi
 
+echo "Login for jenkins-mch.cscs.ch:"
+read -p "user: " user
+read -p "password: " -s password
+echo
+
 refpath=$(dirname "$BASH_SOURCE")/../pyutils/perftest/references
 
 for domain in 128 256; do
     for label in ault dom daint-cn tsa; do
         for env in cray hip nvcc_cray nvcc_cray_cxx20 nvcc_gcc; do
             current="${label%-*}_$env/$domain.json"
-            src="http://jenkins-mch.cscs.ch/view/GridTools/job/GridTools_perftest_PR/$1/env=$env,label=$label/artifact/build/pyutils/perftest/results/$current"
+            src="https://jenkins-mch.cscs.ch/view/GridTools/job/GridTools_perftest_PR/$1/env=$env,label=$label/artifact/build/pyutils/perftest/results/$current"
 
             tmp=$(mktemp)
-            wget -q -O "$tmp" "$src"
+            curl -fs -u "$user:$password" -o "$tmp" "$src"
 
             if [[ $? == 0 ]]; then
                 dst="$refpath/$current"