Add CudaBackend, CudaSympyPrinter

Add CudaBackend, CudaSympyPrinter to extract CUDA-specific code from CBackend, CustomSympyPrinter

Cuda built-ins are added to CudaSympyPrinter.known_functions to use them as sympy.Function

pystencils_tests/test_cuda_known_functions.py

+# -*- coding: utf-8 -*-
+#
+# Copyright © 2019 Stephan Seitz <stephan.seitz@fau.de>
+#
+# Distributed under terms of the GPLv3 license.
+
+"""
+
+"""
+import sympy
+
+import pystencils
+from pystencils.astnodes import get_dummy_symbol
+from pystencils.backends.cuda_backend import CudaSympyPrinter
+from pystencils.data_types import address_of
+
+
+def test_cuda_known_functions():
+    printer = CudaSympyPrinter()
+    print(printer.known_functions)
+
+    x, y = pystencils.fields('x,y: float32 [2d]')
+
+    assignments = pystencils.AssignmentCollection({
+        get_dummy_symbol(): sympy.Function('atomicAdd')(address_of(y.center()), 2),
+        y.center():  sympy.Function('rsqrtf')(x[0, 0])
+    })
+
+    ast = pystencils.create_kernel(assignments, 'gpu')
+    print(pystencils.show_code(ast))
+    kernel = ast.compile()
+    assert(kernel is not None)
+
+
+def test_cuda_but_not_c():
+    x, y = pystencils.fields('x,y: float32 [2d]')
+
+    assignments = pystencils.AssignmentCollection({
+        get_dummy_symbol(): sympy.Function('atomicAdd')(address_of(y.center()), 2),
+        y.center():  sympy.Function('rsqrtf')(x[0, 0])
+    })
+
+    ast = pystencils.create_kernel(assignments, 'cpu')
+    code = str(pystencils.show_code(ast))
+    assert "Not supported" in code
+
+
+def test_cuda_unknown():
+    x, y = pystencils.fields('x,y: float32 [2d]')
+
+    assignments = pystencils.AssignmentCollection({
+        get_dummy_symbol(): sympy.Function('wtf')(address_of(y.center()), 2),
+    })
+
+    ast = pystencils.create_kernel(assignments, 'gpu')
+    code = str(pystencils.show_code(ast))
+    print(code)
+    assert "Not supported" in code
+
+
+def main():
+    test_cuda_known_functions()
+    test_cuda_but_not_c()
+    test_cuda_unknown()
+
+
+if __name__ == '__main__':
+    main()