Fix indexing

pystencils/gpu/indexing.py

@@ -6,7 +6,7 @@ from typing import Tuple
 import sympy as sp
 from sympy.core.cache import cacheit
 
-from pystencils.astnodes import Block, Conditional
+from pystencils.astnodes import Block, Conditional, LoopOverCoordinate, SympyAssignment
 from pystencils.typing import TypedSymbol, create_type
 from pystencils.integer_functions import div_ceil, div_floor
 from pystencils.sympyextensions import is_integer_sequence, prod
@@ -169,7 +169,8 @@ class BlockIndexing(AbstractIndexing):
 
     def call_parameters(self, arr_shape):
         numeric_iteration_slice = _get_numeric_iteration_slice(self._iteration_space, arr_shape)
-        widths = [len(range(*s.indices(s.stop))) for s in numeric_iteration_slice]
+        widths = [s.stop - s.start for s in numeric_iteration_slice]
+        widths = [w if w > 0 else 1 for w in widths]
 
         extend_bs = (1,) * (3 - len(self._block_size))
         block_size = self._block_size + extend_bs
@@ -192,7 +193,7 @@ class BlockIndexing(AbstractIndexing):
     def guard(self, kernel_content, arr_shape):
         arr_shape = arr_shape[:self._dim]
         numeric_iteration_slice = _get_numeric_iteration_slice(self._iteration_space, arr_shape)
-        end = [s.stop for s in numeric_iteration_slice]
+        end = [s.stop if s.stop != 0 else 1 for s in numeric_iteration_slice]
 
         conditions = [c < e for c, e in zip(self.coordinates, end)]
         for cuda_index, iter_slice in zip(self.cuda_indices, self._iteration_space):

pystencils/gpu/kernelcreation.py

@@ -69,6 +69,8 @@ def create_cuda_kernel(assignments: Union[AssignmentCollection, NodeCollection],
     else:
         iteration_space = normalize_slice(iteration_slice, common_shape)
 
+    iteration_space = tuple([s if isinstance(s, slice) else slice(s, s, 1) for s in iteration_space])
+
     indexing = indexing_creator(iteration_space=iteration_space, data_layout=common_field.layout)
     coord_mapping = indexing.coordinates