Optimizations: fix indexing of restrict views adding extra operations (…

…#289)

pykokkos/core/optimizations/restrict_views.py

@@ -4,7 +4,7 @@
 from typing import Any, Dict, List, Optional, Set, Tuple, Union
 
 from pykokkos.core import cppast
-from pykokkos.interface import Subview, View, ViewType, Trait
+from pykokkos.interface import Layout, Subview, View, ViewType, Trait
 
 
 def may_share_memory(a, b) -> bool:
@@ -59,7 +59,7 @@ def may_share_memory(a, b) -> bool:
 
     return False
 
-def get_restrict_views(views: Dict[str, ViewType]) -> Tuple[Set[str], str]:
+def get_restrict_views(views: Dict[str, ViewType]) -> Tuple[Dict[str, ViewType], str]:
     """
     Identify views that do not alias each other to apply the restrict
     keyword to
@@ -69,7 +69,7 @@ def get_restrict_views(views: Dict[str, ViewType]) -> Tuple[Set[str], str]:
     """
 
     # Map from base view id() to a list of views that alias that view
-    base_view_ids: Dict[int, Set[str]] = {}
+    base_view_ids: Dict[int, Dict[str, ViewType]] = {}
     # Map from view name to the xp_array it has
     xp_arrays: Dict[str, Any] = {}
 
@@ -98,11 +98,11 @@ def get_restrict_views(views: Dict[str, ViewType]) -> Tuple[Set[str], str]:
 
         view_id: int = id(base_view)
         if view_id in base_view_ids:
-            base_view_ids[view_id].add(view_name)
+            base_view_ids[view_id][view_name] = view
         else:
-            base_view_ids[view_id] = {view_name}
+            base_view_ids[view_id] = {view_name: view}
 
-    restricted_views: Set[str] = set()
+    restricted_views: Dict[str, ViewType] = {}
     for view_id, view_set in base_view_ids.items():
         # if len(view_set) == 1:
         restricted_views.update(view_set)
@@ -127,7 +127,9 @@ def get_restrict_views(views: Dict[str, ViewType]) -> Tuple[Set[str], str]:
                     aliasing_arrays.add(name)
                     aliasing_arrays.add(other_name)
 
-    restricted_views -= aliasing_arrays
+    for arr in aliasing_arrays:
+        restricted_views.pop(arr, None)
+
     restricted_signature: str = hashlib.md5("".join(sorted(restricted_views)).encode()).hexdigest()
 
     return restricted_views, restricted_signature
@@ -219,7 +221,7 @@ def define_restrict_function(functor: cppast.RecordDecl, operation: str, workuni
     return method
 
 
-def index_restrict_view(name: cppast.DeclRefExpr, indices: List[cppast.Expr]) -> cppast.ArraySubscriptExpr:
+def index_restrict_view(name: cppast.DeclRefExpr, indices: List[cppast.Expr], view: ViewType) -> cppast.ArraySubscriptExpr:
     """
     Get the indexing operation of a particular view with a given list
     of indices
@@ -229,12 +231,24 @@ def index_restrict_view(name: cppast.DeclRefExpr, indices: List[cppast.Expr]) ->
     """
 
     restrict_name: cppast.DeclRefExpr = get_restrict_ptr_name(name)
+    full_index: cppast.Expr
+
+    # Subviews could be strided
+    if isinstance(view, Subview) or view.rank() > 2:
+        full_index = cppast.BinaryOperator(indices[0], get_stride_name(name, 0), cppast.BinaryOperatorKind.Mul)
+        for i, index in enumerate(indices[1:]):
+            current_stride: cppast.DeclRefExpr = get_stride_name(name, i + 1) # Add one since we did zero before the loop
+            current_mul = cppast.BinaryOperator(index, current_stride, cppast.BinaryOperatorKind.Mul)
+            full_index = cppast.BinaryOperator(current_mul, full_index, cppast.BinaryOperatorKind.Add)
 
-    full_index: cppast.Expr = cppast.BinaryOperator(indices[0], get_stride_name(name, 0), cppast.BinaryOperatorKind.Mul)
-    for i, index in enumerate(indices[1:]):
-        current_stride: cppast.DeclRefExpr = get_stride_name(name, i + 1) # Add one since we did zero before the loop
-        current_mul = cppast.BinaryOperator(index, current_stride, cppast.BinaryOperatorKind.Mul)
-        full_index = cppast.BinaryOperator(current_mul, full_index, cppast.BinaryOperatorKind.Add)
+    else:
+        if view.rank() == 1:
+            full_index = indices[0]
+        elif view.rank() == 2:
+            if view.layout is Layout.LayoutRight:
+                full_index = cppast.BinaryOperator(cppast.BinaryOperator(indices[0], get_stride_name(name, 0), cppast.BinaryOperatorKind.Mul), indices[1], cppast.BinaryOperatorKind.Add)
+            elif view.layout is Layout.LayoutLeft:
+                full_index = cppast.BinaryOperator(cppast.BinaryOperator(indices[1], get_stride_name(name, 1), cppast.BinaryOperatorKind.Mul), indices[0], cppast.BinaryOperatorKind.Add)
 
     return cppast.ArraySubscriptExpr(restrict_name, [full_index])
 

pykokkos/core/visitors/pykokkos_visitor.py

@@ -270,7 +270,11 @@ def visit_Subscript(self, node: ast.Subscript) -> Union[cppast.ArraySubscriptExp
             unfused_name: str = r.group(1) if r else ref.declname
 
             if "PK_RESTRICT" in os.environ and unfused_name in self.restrict_views or name in self.restrict_views:
-                subscript = index_restrict_view(ref, args)
+                if unfused_name in self.restrict_views:
+                    v = self.restrict_views[unfused_name]
+                else:
+                    v = self.restrict_views[name]
+                subscript = index_restrict_view(ref, args, v)
             else:
                 subscript = cppast.CallExpr(ref, args)