diff --git a/pystencils/astnodes.py b/pystencils/astnodes.py
index 393396aa2d073c77e8df6ff627860164c9cfe526..b24138286c024d0e7b546488289e552620a6d125 100644
--- a/pystencils/astnodes.py
+++ b/pystencils/astnodes.py
@@ -509,6 +509,13 @@ class SympyAssignment(Node):
self.lhs = fast_subs(self.lhs, subs_dict)
self.rhs = fast_subs(self.rhs, subs_dict)
+ def optimize(self, optimizations):
+ try:
+ from sympy.codegen.rewriting import optimize
+ self.rhs = optimize(self.rhs, optimizations)
+ except Exception:
+ pass
+
@property
def args(self):
return [self._lhs_symbol, self.rhs]
diff --git a/pystencils/data_types.py b/pystencils/data_types.py
index 86ce1747d2b83cea80d1974121dbe79959c0ba8c..faa8867188b36ae3c3f355b09b2dc41d99a98086 100644
--- a/pystencils/data_types.py
+++ b/pystencils/data_types.py
@@ -82,6 +82,37 @@ class cast_func(sp.Function):
def dtype(self):
return self.args[1]
+ @property
+ def is_integer(self):
+ if hasattr(self.dtype, 'numpy_dtype'):
+ return np.issubdtype(self.dtype.numpy_dtype, np.integer) or super().is_integer
+ else:
+ return super().is_integer
+
+ @property
+ def is_negative(self):
+ if hasattr(self.dtype, 'numpy_dtype'):
+ if np.issubdtype(self.dtype.numpy_dtype, np.unsignedinteger):
+ return False
+
+ return super().is_negative
+
+ @property
+ def is_nonnegative(self):
+ if self.is_negative is False:
+ return True
+ else:
+ return super().is_nonnegative
+
+ @property
+ def is_real(self):
+ if hasattr(self.dtype, 'numpy_dtype'):
+ return np.issubdtype(self.dtype.numpy_dtype, np.integer) or \
+ np.issubdtype(self.dtype.numpy_dtype, np.floating) or \
+ super().is_real
+ else:
+ return super().is_real
+
# noinspection PyPep8Naming
class boolean_cast_func(cast_func, Boolean):
diff --git a/pystencils/integer_functions.py b/pystencils/integer_functions.py
index b54bbaab216676b62244c6ab907e36af2f762959..fa5a4d739433658e1dff26389396eb296c6e4099 100644
--- a/pystencils/integer_functions.py
+++ b/pystencils/integer_functions.py
@@ -25,6 +25,10 @@ class IntegerFunctionTwoArgsMixIn(sp.Function):
raise ValueError("Integer functions can only be constructed with typed expressions")
return super().__new__(cls, *args)
+ @property
+ def is_integer(self):
+ return True
+
# noinspection PyPep8Naming
class bitwise_xor(IntegerFunctionTwoArgsMixIn):
diff --git a/pystencils/math_optimizations.py b/pystencils/math_optimizations.py
new file mode 100644
index 0000000000000000000000000000000000000000..ad0114782e15977fb329baacfb6ad4b6bac1e33b
--- /dev/null
+++ b/pystencils/math_optimizations.py
@@ -0,0 +1,46 @@
+"""
+Default Sympy optimizations applied in pystencils kernels using :func:`sympy.codegen.rewriting.optimize`.
+
+See :func:`sympy.codegen.rewriting.optimize`.
+"""
+
+
+import itertools
+
+from pystencils import Assignment
+from pystencils.astnodes import SympyAssignment
+
+try:
+ from sympy.codegen.rewriting import optims_c99, optimize
+ from sympy.codegen.rewriting import ReplaceOptim
+ HAS_REWRITING = True
+
+ # Evaluates all constant terms
+ evaluate_constant_terms = ReplaceOptim(
+ lambda e: hasattr(e, 'is_constant') and e.is_constant and not e.is_integer,
+ lambda p: p.evalf()
+ )
+
+ optims_pystencils_cpu = [evaluate_constant_terms] + list(optims_c99)
+ optims_pystencils_gpu = [evaluate_constant_terms] + list(optims_c99)
+except ImportError:
+ from warnings import warn
+ warn("Could not import ReplaceOptim, optims_c99, optimize from sympy.codegen.rewriting."
+ "Please update your sympy installation!")
+ optims_c99 = []
+ optims_pystencils_cpu = []
+ optims_pystencils_gpu = []
+ HAS_REWRITING = False
+
+
+def optimize_assignments(assignments, optimizations):
+
+ if HAS_REWRITING:
+ assignments = [Assignment(a.lhs, optimize(a.rhs, optimizations))
+ if hasattr(a, 'lhs')
+ else a for a in assignments]
+ assignments_nodes = [a.atoms(SympyAssignment) for a in assignments]
+ for a in itertools.chain.from_iterable(assignments_nodes):
+ a.optimize(optimizations)
+
+ return assignments
diff --git a/pystencils/simp/assignment_collection.py b/pystencils/simp/assignment_collection.py
index fa437a5d0fbe49ed04cabeaaf3e22d335b939819..1e9a4c47e64e5a5683076a6fa912bd7298aa6c69 100644
--- a/pystencils/simp/assignment_collection.py
+++ b/pystencils/simp/assignment_collection.py
@@ -347,7 +347,7 @@ class AssignmentCollection:
return result
def __iter__(self):
- return self.main_assignments.__iter__()
+ return self.all_assignments.__iter__()
@property
def main_assignments_dict(self):
diff --git a/pystencils_tests/test_sympy_optimizations.py b/pystencils_tests/test_sympy_optimizations.py
new file mode 100644
index 0000000000000000000000000000000000000000..745b936ea7d0e3ce5da6c684dee42c56c09dd835
--- /dev/null
+++ b/pystencils_tests/test_sympy_optimizations.py
@@ -0,0 +1,60 @@
+import pytest
+import sympy as sp
+
+import pystencils
+from pystencils.math_optimizations import HAS_REWRITING, optimize_assignments, optims_pystencils_cpu
+
+
+@pytest.mark.skipif(not HAS_REWRITING, reason="need sympy.codegen.rewriting")
+def test_sympy_optimizations():
+ for target in ('cpu', 'gpu'):
+ x, y, z = pystencils.fields('x, y, z: float32[2d]')
+
+ # Triggers Sympy's expm1 optimization
+ assignments = pystencils.AssignmentCollection({
+ x[0, 0]: sp.exp(y[0, 0]) - 1
+ })
+
+ assignments = optimize_assignments(assignments, optims_pystencils_cpu)
+
+ ast = pystencils.create_kernel(assignments, target=target)
+ code = str(pystencils.show_code(ast))
+ assert 'expm1(' in code
+
+
+@pytest.mark.skipif(not HAS_REWRITING, reason="need sympy.codegen.rewriting")
+def test_evaluate_constant_terms():
+ for target in ('cpu', 'gpu'):
+ x, y, z = pystencils.fields('x, y, z: float32[2d]')
+
+ # Triggers Sympy's expm1 optimization
+ assignments = pystencils.AssignmentCollection({
+ x[0, 0]: -sp.cos(1) + y[0, 0]
+ })
+
+ assignments = optimize_assignments(assignments, optims_pystencils_cpu)
+
+ ast = pystencils.create_kernel(assignments, target=target)
+ code = str(pystencils.show_code(ast))
+ assert 'cos(' not in code
+ print(code)
+
+
+@pytest.mark.skipif(not HAS_REWRITING, reason="need sympy.codegen.rewriting")
+def test_do_not_evaluate_constant_terms():
+ optimizations = pystencils.math_optimizations.optims_pystencils_cpu
+ optimizations.remove(pystencils.math_optimizations.evaluate_constant_terms)
+
+ for target in ('cpu', 'gpu'):
+ x, y, z = pystencils.fields('x, y, z: float32[2d]')
+
+ assignments = pystencils.AssignmentCollection({
+ x[0, 0]: -sp.cos(1) + y[0, 0]
+ })
+
+ optimize_assignments(assignments, optimizations)
+
+ ast = pystencils.create_kernel(assignments, target=target)
+ code = str(pystencils.show_code(ast))
+ assert 'cos(' in code
+ print(code)