Merge pull request #1896 from IntelPython/accumulator-maint-tweak

[MAINT] Save repeated expression in accumulation functor operator to a variable

Author: oleksandr-pavlyk

dpctl/tensor/libtensor/include/kernels/accumulators.hpp

@@ -227,23 +227,22 @@ inclusive_scan_base_step(sycl::queue &exec_q,
 
 #pragma unroll
             for (nwiT m_wi = 0; m_wi < n_wi; ++m_wi) {
+                const size_t i_m_wi = i + m_wi;
                 if constexpr (!include_initial) {
                     local_iscan[m_wi] =
-                        (i + m_wi < acc_nelems)
-                            ? transformer(
-                                  input[inp_iter_offset +
-                                        inp_indexer(s0 + s1 * (i + m_wi))])
+                        (i_m_wi < acc_nelems)
+                            ? transformer(input[inp_iter_offset +
+                                                inp_indexer(s0 + s1 * i_m_wi)])
                             : identity;
                 }
                 else {
                     // shift input to the left by a single element relative to
                     // output
                     local_iscan[m_wi] =
-                        (i + m_wi < acc_nelems && i + m_wi > 0)
+                        (i_m_wi < acc_nelems && i_m_wi > 0)
                             ? transformer(
                                   input[inp_iter_offset +
-                                        inp_indexer((s0 + s1 * (i + m_wi)) -
-                                                    1)])
+                                        inp_indexer((s0 + s1 * i_m_wi) - 1)])
                             : identity;
                 }
             }
@@ -280,9 +279,9 @@ inclusive_scan_base_step(sycl::queue &exec_q,
                 local_iscan[m_wi] = scan_op(local_iscan[m_wi], addand);
             }
 
-            for (nwiT m_wi = 0; (m_wi < n_wi) && (i + m_wi < acc_nelems);
-                 ++m_wi)
-            {
+            const nwiT m_max =
+                std::min<nwiT>(n_wi, std::max(i, acc_nelems) - i);
+            for (nwiT m_wi = 0; m_wi < m_max; ++m_wi) {
                 output[out_iter_offset + out_indexer(i + m_wi)] =
                     local_iscan[m_wi];
             }