Merge branch 'address_of-function' into 'master'

Address of SymPy-Function `address_of`

See merge request !1

pystencils/backends/cbackend.py

@@ -5,7 +5,11 @@ from typing import Set
 from sympy.printing.ccode import C89CodePrinter
 
 from pystencils.cpu.vectorization import vec_any, vec_all
-from pystencils.fast_approximation import fast_division, fast_sqrt, fast_inv_sqrt
+from pystencils.data_types import (PointerType, VectorType, address_of,
+                                   cast_func, create_type, reinterpret_cast_func,
+                                   get_type_of_expression,
+                                   vector_memory_access)
+from pystencils.fast_approximation import fast_division, fast_inv_sqrt, fast_sqrt
 
 try:
     from sympy.printing.ccode import C99CodePrinter as CCodePrinter
@@ -15,8 +19,6 @@ except ImportError:
 from pystencils.integer_functions import bitwise_xor, bit_shift_right, bit_shift_left, bitwise_and, \
     bitwise_or, modulo_ceil, int_div, int_power_of_2
 from pystencils.astnodes import Node, KernelFunction
-from pystencils.data_types import create_type, PointerType, get_type_of_expression, VectorType, cast_func, \
-    vector_memory_access, reinterpret_cast_func
 
 __all__ = ['generate_c', 'CustomCodeNode', 'PrintNode', 'get_headers', 'CustomSympyPrinter']
 
@@ -276,6 +278,9 @@ class CustomSympyPrinter(CCodePrinter):
         if isinstance(expr, reinterpret_cast_func):
             arg, data_type = expr.args
             return "*((%s)(& %s))" % (PointerType(data_type, restrict=False), self._print(arg))
+        elif isinstance(expr, address_of):
+            assert len(expr.args) == 1, "address_of must only have one argument"
+            return "&(%s)" % self._print(expr.args[0])
         elif isinstance(expr, cast_func):
             arg, data_type = expr.args
             if isinstance(arg, sp.Number):

pystencils/data_types.py

@@ -14,6 +14,33 @@ from pystencils.utils import all_equal
 from sympy.logic.boolalg import Boolean
 
 
+# noinspection PyPep8Naming
+class address_of(sp.Function):
+    is_Atom = True
+
+    def __new__(cls, arg):
+        obj = sp.Function.__new__(cls, arg)
+        return obj
+
+    @property
+    def canonical(self):
+        if hasattr(self.args[0], 'canonical'):
+            return self.args[0].canonical
+        else:
+            raise NotImplementedError()
+
+    @property
+    def is_commutative(self):
+        return self.args[0].is_commutative
+
+    @property
+    def dtype(self):
+        if hasattr(self.args[0], 'dtype'):
+            return PointerType(self.args[0].dtype, restrict=True)
+        else:
+            return PointerType('void', restrict=True)
+
+
 # noinspection PyPep8Naming
 class cast_func(sp.Function):
     is_Atom = True

pystencils_tests/test_address_of.py

+
+"""
+Test of pystencils.data_types.address_of
+"""
+
+from pystencils.data_types import address_of, cast_func, PointerType
+import pystencils
+from pystencils.simp.simplifications import sympy_cse
+import sympy
+
+
+def test_address_of():
+    x, y = pystencils.fields('x,y: int64[2d]')
+    s = pystencils.TypedSymbol('s', PointerType('int64'))
+
+    assignments = pystencils.AssignmentCollection({
+        s: address_of(x[0, 0]),
+        y[0, 0]: cast_func(s, 'int64')
+    }, {})
+
+    ast = pystencils.create_kernel(assignments)
+    code = pystencils.show_code(ast)
+    print(code)
+
+    assignments = pystencils.AssignmentCollection({
+        y[0, 0]: cast_func(address_of(x[0, 0]), 'int64')
+    }, {})
+
+    ast = pystencils.create_kernel(assignments)
+    code = pystencils.show_code(ast)
+    print(code)
+
+
+def test_address_of_with_cse():
+    x, y = pystencils.fields('x,y: int64[2d]')
+    s = pystencils.TypedSymbol('s', PointerType('int64'))
+
+    assignments = pystencils.AssignmentCollection({
+        y[0, 0]: cast_func(address_of(x[0, 0]), 'int64'),
+        x[0, 0]: cast_func(address_of(x[0, 0]), 'int64') + 1
+    }, {})
+
+    ast = pystencils.create_kernel(assignments)
+    code = pystencils.show_code(ast)
+    assignments_cse = sympy_cse(assignments)
+
+    ast = pystencils.create_kernel(assignments_cse)
+    code = pystencils.show_code(ast)
+    print(code)
+
+
+def main():
+    test_address_of()
+    test_address_of_with_cse()
+
+
+if __name__ == '__main__':
+    main()