algorithms: inclusive_scan

examples/kokkos/inclusive_scan_team.py

@@ -0,0 +1,58 @@
+import pykokkos as pk
+
+
+@pk.workunit
+def init_data(i: int, view: pk.View1D[int]):
+    view[i] = i + 1
+
+
+# Test inclusive_scan with scratch memory
+@pk.workunit
+def team_scan(team_member: pk.TeamMember, view: pk.View1D[int]):
+    team_size: int = team_member.team_size()
+    offset: int = team_member.league_rank() * team_size
+    localIdx: int = team_member.team_rank()
+    globalIdx: int = offset + localIdx
+    team_rank: int = team_member.team_rank()
+
+    scratch: pk.ScratchView1D[int] = pk.ScratchView1D(
+        team_member.team_scratch(0), team_size
+    )
+
+    scratch[team_rank] = view[globalIdx]
+    team_member.team_barrier()
+
+    pk.inclusive_scan(team_member, scratch)
+    team_member.team_barrier()
+
+    view[globalIdx] = scratch[team_rank]
+
+
+def main():
+    N = 64
+    team_size = 32
+    num_teams = (N + team_size - 1) // team_size
+
+    view: pk.View1D[int] = pk.View([N], int)
+    p_init = pk.RangePolicy(pk.ExecutionSpace.OpenMP, 0, N)
+    pk.parallel_for(p_init, init_data, view=view)
+
+    print(f"Total elements: {N}, Team size: {team_size}, Number of teams: {num_teams}")
+
+    # Use TeamPolicy
+    team_policy = pk.TeamPolicy(pk.ExecutionSpace.OpenMP, num_teams, team_size)
+
+    # for now these functions are useless, since they are not implemented corectly
+    # TODO: implement scratch size setting
+    # scratch_size = pk.ScratchView1D[int].shmem_size(team_size)
+    # team_policy.set_scratch_size(0, pk.PerTeam(scratch_size))
+
+    # Kernel call - just allocate and write to scratch
+    print("Running kernel...")
+    pk.parallel_for(team_policy, team_scan, view=view)
+    print(f"View, splitted by two groups of size = {team_size}")
+    print(view)
+
+
+if __name__ == "__main__":
+    main()

pykokkos/core/translators/static.py

@@ -268,6 +268,7 @@ def generate_includes(self) -> str:
             "Kokkos_Core.hpp",
             "Kokkos_Random.hpp",
             "Kokkos_Sort.hpp",
+            "Kokkos_StdAlgorithms.hpp",
             "fstream",
             "iostream",
             "cmath",
@@ -290,6 +291,7 @@ def generate_cast_includes(self) -> str:
             "Kokkos_Core.hpp",
             "Kokkos_Random.hpp",
             "Kokkos_Sort.hpp",
+            "Kokkos_StdAlgorithms.hpp",
             "fstream",
             "iostream",
             "cmath",

pykokkos/core/translators/symbols_pass.py

@@ -54,7 +54,7 @@ def __init__(self, members: PyKokkosMembers, pk_import: str, path: str):
         self.global_symbols.update(math_functions)
         self.global_symbols.update(allowed_types)
         self.global_symbols.update(view_dtypes)
-        self.global_symbols.update(["self", "range", "math", "List", "abs"])
+        self.global_symbols.update(["self", "range", "math", "List", "abs", "inclusive_scan"])
         self.global_symbols.add(pk_import)
 
         self.global_symbols.update([field.declname for field in members.fields])

pykokkos/core/visitors/workunit_visitor.py

@@ -318,6 +318,51 @@ def visit_Call(self, node: ast.Call) -> cppast.CallExpr:
 
             return real_number_call
 
+        # Kokkos `inclusive_scan`
+        if name == "inclusive_scan":
+            # Check if it's called via pk.inclusive_scan
+            is_pk_call = (
+                isinstance(node.func, ast.Attribute)
+                and isinstance(node.func.value, ast.Name)
+                and node.func.value.id == self.pk_import
+            )
+
+            if not is_pk_call:
+                return super().visit_Call(node)
+
+            # Expected signature: pk.inclusive_scan(team_member, view, length)
+            # or: pk.inclusive_scan(team_member, view) - uses view size
+            if len(args) < 2 or len(args) > 3:
+                self.error(
+                    node,
+                    "pk.inclusive_scan() takes 2 or 3 arguments: team_member, view, [length]",
+                )
+
+            team_member_expr = args[0]
+            view_expr = args[1]
+
+            # Create Kokkos::Experimental::begin() and end() calls
+            begin_function = cppast.DeclRefExpr("Kokkos::Experimental::begin")
+            end_function = cppast.DeclRefExpr("Kokkos::Experimental::end")
+            view_begin = cppast.CallExpr(begin_function, [view_expr])
+
+            if len(args) == 3:
+                # Use provided length: begin + length
+                length_expr = args[2]
+                view_begin_for_end = cppast.CallExpr(begin_function, [view_expr])
+                view_end = cppast.BinaryOperator(
+                    view_begin_for_end, length_expr, cppast.BinaryOperatorKind.Add
+                )
+            else:
+                # Use end() when no length is provided
+                view_end = cppast.CallExpr(end_function, [view_expr])
+
+            # Create Kokkos::Experimental::inclusive_scan call
+            function = cppast.DeclRefExpr("Kokkos::Experimental::inclusive_scan")
+            scan_args = [team_member_expr, view_begin, view_end, view_begin]
+
+            return cppast.CallExpr(function, scan_args)
+
         return super().visit_Call(node)
 
     def is_nested_call(self, node: ast.FunctionDef) -> bool:

pykokkos/interface/__init__.py

@@ -1,4 +1,5 @@
 from .accumulator import Acc
+from .algorithms.inclusive_scan import inclusive_scan
 from .atomic.atomic_fetch_op import (
     atomic_fetch_add, atomic_fetch_and, atomic_fetch_div,
     atomic_fetch_lshift, atomic_fetch_max, atomic_fetch_min,

pykokkos/interface/algorithms/__init__.py

@@ -0,0 +1,3 @@
+from .inclusive_scan import inclusive_scan
+
+__all__ = ["inclusive_scan"]

pykokkos/interface/algorithms/inclusive_scan.py

@@ -0,0 +1,15 @@
+from pykokkos.interface.hierarchical import TeamMember
+from pykokkos.interface.views import ViewType
+
+
+def inclusive_scan(team_member: TeamMember, view: ViewType, size: int = -1):
+    """
+    Perform an inclusive scan on a view using a team member.
+
+    **`team_barrier()` should always be called before accessing scanned data.**
+
+    :param team_member: the team member
+    :param view: the view to scan
+    :param size: (optional) the number of elements to scan
+    """
+    pass