[SYCLomatic] Add equal_range implementation in helper function(#861)

Signed-off-by: Dan Hoeflinger <[email protected]>

Author: danhoeflinger

clang/runtime/dpct-rt/include/dpl_extras/algorithm.h.inc

@@ -2020,6 +2020,52 @@ inline void reduce_argmin(_ExecutionPolicy &&policy, Iter1 input, Iter2 output,
 }
 // DPCT_LABEL_END
 
+// DPCT_LABEL_BEGIN|equal_range|dpct
+// DPCT_DEPENDENCY_BEGIN
+// DplExtrasIterators|make_constant_iterator
+// DPCT_DEPENDENCY_END
+// DPCT_CODE
+template <typename _ExecutionPolicy, typename Iter1,
+          typename ValueLessComparable, typename StrictWeakOrdering>
+inline ::std::pair<Iter1, Iter1>
+equal_range(_ExecutionPolicy &&policy, Iter1 start, Iter1 end,
+            const ValueLessComparable &value, StrictWeakOrdering comp) {
+
+  auto size = ::std::distance(start, end);
+  auto zip_start =
+      oneapi::dpl::make_zip_iterator(start, dpct::make_counting_iterator(0));
+  auto constant_value_iter = dpct::make_constant_iterator(value);
+  auto reduction = [=](const auto &a, const auto &b) {
+    return oneapi::dpl::__internal::tuple<uint64_t, uint64_t>(
+        ::std::min(::std::get<0>(a), ::std::get<0>(b)),
+        ::std::max(::std::get<1>(::std::forward<decltype(a)>(a)),
+                   ::std::get<1>(::std::forward<decltype(b)>(b))));
+  };
+  auto trans = [=](const auto &a, const auto &b) {
+    return ::oneapi::dpl::__internal::tuple<uint64_t, uint64_t>(
+        comp(::std::get<0>(a), b) ? size : ::std::get<1>(a),
+        comp(b, ::std::get<0>(a)) ? 0 : ::std::get<1>(a) + 1);
+  };
+
+  auto result = oneapi::dpl::transform_reduce(
+      ::std::forward<_ExecutionPolicy>(policy), zip_start, zip_start + size,
+      constant_value_iter,
+      oneapi::dpl::__internal::tuple<uint64_t, uint64_t>(size, 0), reduction,
+      trans);
+  return ::std::make_pair(start + ::std::get<0>(result),
+                          start + ::std::get<1>(result));
+}
+
+template <typename _ExecutionPolicy, typename Iter1,
+          typename ValueLessComparable>
+inline ::std::pair<Iter1, Iter1> equal_range(_ExecutionPolicy &&policy,
+                                             Iter1 start, Iter1 end,
+                                             const ValueLessComparable &value) {
+  return equal_range(::std::forward<_ExecutionPolicy>(policy), start, end,
+                     value, internal::__less());
+}
+// DPCT_LABEL_END
+
 } // end namespace dpct
 
 #endif

clang/test/dpct/helper_files_ref/include/dpl_extras/algorithm.h

@@ -1675,6 +1675,46 @@ inline void reduce_argmin(_ExecutionPolicy &&policy, Iter1 input, Iter2 output,
   ::std::copy(::std::forward<_ExecutionPolicy>(policy), ret, ret + 1, output);
 }
 
+template <typename _ExecutionPolicy, typename Iter1,
+          typename ValueLessComparable, typename StrictWeakOrdering>
+inline ::std::pair<Iter1, Iter1>
+equal_range(_ExecutionPolicy &&policy, Iter1 start, Iter1 end,
+            const ValueLessComparable &value, StrictWeakOrdering comp) {
+
+  auto size = ::std::distance(start, end);
+  auto zip_start =
+      oneapi::dpl::make_zip_iterator(start, dpct::make_counting_iterator(0));
+  auto constant_value_iter = dpct::make_constant_iterator(value);
+  auto reduction = [=](const auto &a, const auto &b) {
+    return oneapi::dpl::__internal::tuple<uint64_t, uint64_t>(
+        ::std::min(::std::get<0>(a), ::std::get<0>(b)),
+        ::std::max(::std::get<1>(::std::forward<decltype(a)>(a)),
+                   ::std::get<1>(::std::forward<decltype(b)>(b))));
+  };
+  auto trans = [=](const auto &a, const auto &b) {
+    return ::oneapi::dpl::__internal::tuple<uint64_t, uint64_t>(
+        comp(::std::get<0>(a), b) ? size : ::std::get<1>(a),
+        comp(b, ::std::get<0>(a)) ? 0 : ::std::get<1>(a) + 1);
+  };
+
+  auto result = oneapi::dpl::transform_reduce(
+      ::std::forward<_ExecutionPolicy>(policy), zip_start, zip_start + size,
+      constant_value_iter,
+      oneapi::dpl::__internal::tuple<uint64_t, uint64_t>(size, 0), reduction,
+      trans);
+  return ::std::make_pair(start + ::std::get<0>(result),
+                          start + ::std::get<1>(result));
+}
+
+template <typename _ExecutionPolicy, typename Iter1,
+          typename ValueLessComparable>
+inline ::std::pair<Iter1, Iter1> equal_range(_ExecutionPolicy &&policy,
+                                             Iter1 start, Iter1 end,
+                                             const ValueLessComparable &value) {
+  return equal_range(::std::forward<_ExecutionPolicy>(policy), start, end,
+                     value, internal::__less());
+}
+
 } // end namespace dpct
 
 #endif