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];
  }