Fixup for DestructuringBindingsForFieldClass

- rename header Field.h is not a unique name in waLBerla context
- add PyStencilsField.h
- bindings were lacking data type

pystencils/astnodes.py

@@ -670,10 +670,10 @@ class DestructuringBindingsForFieldClass(Node):
     """
     CLASS_TO_MEMBER_DICT = {
         FieldPointerSymbol: "data",
-        FieldShapeSymbol: "shape",
-        FieldStrideSymbol: "stride"
+        FieldShapeSymbol: "shape[%i]",
+        FieldStrideSymbol: "stride[%i]"
     }
-    CLASS_NAME_TEMPLATE = jinja2.Template("Field<{{ dtype }}, {{ ndim }}>")
+    CLASS_NAME_TEMPLATE = jinja2.Template("PyStencilsField<{{ dtype }}, {{ ndim }}>")
 
     @property
     def fields_accessed(self) -> Set['ResolvedFieldAccess']:
@@ -682,7 +682,7 @@ class DestructuringBindingsForFieldClass(Node):
 
     def __init__(self, body):
         super(DestructuringBindingsForFieldClass, self).__init__()
-        self.headers = ['<Field.h>']
+        self.headers = ['<PyStencilsField.h>']
         self.body = body
 
     @property

pystencils/backends/cbackend.py

@@ -6,15 +6,14 @@ import sympy as sp
 from sympy.core import S
 from sympy.printing.ccode import C89CodePrinter
 
-from pystencils.astnodes import DestructuringBindingsForFieldClass, KernelFunction, Node
+from pystencils.astnodes import KernelFunction, Node
 from pystencils.cpu.vectorization import vec_all, vec_any
 from pystencils.data_types import (
-    PointerType, VectorType, address_of, cast_func, create_type, get_type_of_expression,
-    reinterpret_cast_func, vector_memory_access)
+    PointerType, VectorType, address_of, cast_func, create_type, get_type_of_expression, reinterpret_cast_func,
+    vector_memory_access)
 from pystencils.fast_approximation import fast_division, fast_inv_sqrt, fast_sqrt
 from pystencils.integer_functions import (
-    bit_shift_left, bit_shift_right, bitwise_and, bitwise_or, bitwise_xor,
-    int_div, int_power_of_2, modulo_ceil)
+    bit_shift_left, bit_shift_right, bitwise_and, bitwise_or, bitwise_xor, int_div, int_power_of_2, modulo_ceil)
 from pystencils.kernelparameters import FieldPointerSymbol
 
 try:
@@ -260,14 +259,15 @@ class CBackend:
             result += "else " + false_block
         return result
 
-    def _print_DestructuringBindingsForFieldClass(self, node: Node):
+    def _print_DestructuringBindingsForFieldClass(self, node):
         # Define all undefined symbols
         undefined_field_symbols = node.symbols_defined
-        destructuring_bindings = ["%s = %s.%s%s;" %
-                                  (u.name,
+        destructuring_bindings = ["%s %s = %s.%s;" %
+                                  (u.dtype,
+                                   u.name,
                                    u.field_name if hasattr(u, 'field_name') else u.field_names[0],
-                                   DestructuringBindingsForFieldClass.CLASS_TO_MEMBER_DICT[u.__class__],
-                                   "" if type(u) == FieldPointerSymbol else ("[%i]" % u.coordinate))
+                                   node.CLASS_TO_MEMBER_DICT[u.__class__] %
+                                   (() if type(u) == FieldPointerSymbol else (u.coordinate,)))
                                   for u in undefined_field_symbols
                                   ]
         destructuring_bindings.sort()  # only for code aesthetics

pystencils/include/PyStencilsField.h

+#pragma once
+
+extern "C++" {
+#ifdef __CUDA_ARCH__
+template <typename DTYPE_T, std::size_t DIMENSION> struct PyStencilsField {
+  DTYPE_T *data;
+  DTYPE_T shape[DIMENSION];
+  DTYPE_T stride[DIMENSION];
+};
+#else
+#include <array>
+
+template <typename DTYPE_T, std::size_t DIMENSION> struct PyStencilsField {
+  DTYPE_T *data;
+  std::array<DTYPE_T, DIMENSION> shape;
+  std::array<DTYPE_T, DIMENSION> stride;
+};
+#endif
+}

pystencils_tests/test_destructuring_field_class.py

 import sympy
+import jinja2
+
 
 import pystencils
 from pystencils.astnodes import DestructuringBindingsForFieldClass
+from pystencils.kernelparameters import  FieldPointerSymbol, FieldShapeSymbol, FieldStrideSymbol
+
 
 
 def test_destructuring_field_class():
@@ -10,15 +14,39 @@ def test_destructuring_field_class():
     normal_assignments = pystencils.AssignmentCollection([pystencils.Assignment(
         z[0, 0], x[0, 0] * sympy.log(x[0, 0] * y[0, 0]))], [])
 
-    ast = pystencils.create_kernel(normal_assignments)
+    ast = pystencils.create_kernel(normal_assignments, target='gpu')
     print(pystencils.show_code(ast))
 
     ast.body = DestructuringBindingsForFieldClass(ast.body)
     print(pystencils.show_code(ast))
+    ast.compile()
+
+
+class DestructuringEmojiClass(DestructuringBindingsForFieldClass):
+    CLASS_TO_MEMBER_DICT = {
+        FieldPointerSymbol: "🥶",
+        FieldShapeSymbol: "😳_%i",
+        FieldStrideSymbol: "🥵_%i"
+    }
+    CLASS_NAME_TEMPLATE = jinja2.Template("🤯<{{ dtype }}, {{ ndim }}>")
+    def __init__(self, node):
+        super().__init__(node)
+        self.headers = []
+        
+    
+def test_destructuring_alternative_field_class():
+    z, x, y = pystencils.fields("z, y, x: [2d]")
 
+    normal_assignments = pystencils.AssignmentCollection([pystencils.Assignment(
+        z[0, 0], x[0, 0] * sympy.log(x[0, 0] * y[0, 0]))], [])
+
+    ast = pystencils.create_kernel(normal_assignments, target='gpu')
+    ast.body = DestructuringEmojiClass(ast.body)
+    print(pystencils.show_code(ast))
 
 def main():
     test_destructuring_field_class()
+    test_destructuring_alternative_field_class()
 
 
 if __name__ == '__main__':