def render_Num(self, node):
node.complexity = 0
node.dtype = brian_dtype_from_value(get_node_value(node))
node.scalar = True
node.stateless = True
return node
def render_BinOp(self, node):
if node.dtype == 'float': # only try to collect float type nodes
if node.op.__class__.__name__ in [
'Mult', 'Div', 'Add', 'Sub'
] and not hasattr(node, 'collected'):
newnode = self.bast_renderer.render_node(collect(node))
newnode.collected = True
return self.render_node(newnode)
left = node.left = self.render_node(node.left)
right = node.right = self.render_node(node.right)
node = super(ArithmeticSimplifier, self).render_BinOp(node)
op = node.op
# Handle multiplication by 0 or 1
if op.__class__.__name__ == 'Mult':
for operand, other in [(left, right), (right, left)]:
if operand.__class__.__name__ in ['Num', 'Constant']:
op_value = get_node_value(operand)
if op_value == 0:
# Do not remove stateful functions
if node.stateless:
return _replace_with_zero(operand, node)
if op_value == 1:
# only simplify this if the type wouldn't be cast by the operation
if dtype_hierarchy[operand.dtype] <= dtype_hierarchy[
other.dtype]:
return other
# Handle division by 1, or 0/x
elif op.__class__.__name__ == 'Div':
if left.__class__.__name__ in [
'Num', 'Constant'
] and get_node_value(left) == 0: # 0/x
if node.stateless:
# Do not remove stateful functions
return _replace_with_zero(left, node)
if right.__class__.__name__ in [
'Num', 'Constant'
] and get_node_value(right) == 1: # x/1
# only simplify this if the type wouldn't be cast by the operation
if dtype_hierarchy[right.dtype] <= dtype_hierarchy[left.dtype]:
return left
elif op.__class__.__name__ == 'FloorDiv':
if left.__class__.__name__ in [
'Num', 'Constant'
] and get_node_value(left) == 0: # 0//x
if node.stateless:
# Do not remove stateful functions
return _replace_with_zero(left, node)
# Only optimise floor division by 1 if both numbers are integers,
# for floating point values, floor division by 1 changes the value,
# and division by 1.0 can change the type for an integer value
if (left.dtype == right.dtype == 'integer'
and right.__class__.__name__ in ['Num', 'Constant']
and get_node_value(right) == 1): # x//1
return left
# Handle addition of 0
elif op.__class__.__name__ == 'Add':
for operand, other in [(left, right), (right, left)]:
if operand.__class__.__name__ in [
'Num', 'Constant'
] and get_node_value(operand) == 0:
# only simplify this if the type wouldn't be cast by the operation
if dtype_hierarchy[operand.dtype] <= dtype_hierarchy[
other.dtype]:
return other
# Handle subtraction of 0
elif op.__class__.__name__ == 'Sub':
if right.__class__.__name__ in ['Num', 'Constant'
] and get_node_value(right) == 0:
# only simplify this if the type wouldn't be cast by the operation
if dtype_hierarchy[right.dtype] <= dtype_hierarchy[left.dtype]:
return left
# simplify e.g. 2*float to 2.0*float to make things more explicit: not strictly necessary
# but might be useful for some codegen targets
if node.dtype == 'float' and op.__class__.__name__ in [
'Mult', 'Add', 'Sub', 'Div'
]:
for subnode in [node.left, node.right]:
if (subnode.__class__.__name__ in ['Num', 'Constant']
and not (get_node_value(subnode) is True
or get_node_value(subnode) is False)):
subnode.dtype = 'float'
subnode.value = prefs.core.default_float_dtype(
get_node_value(subnode))
return node
