Commit 54cd7130 authored by Stefan Behnel's avatar Stefan Behnel

optimise calls to int() and float() for casting purposes

parent b6b440e6
......@@ -754,6 +754,8 @@ class OptimizeBuiltinCalls(Visitor.EnvTransform):
return self._dispatch_to_handler(
node, node.function, arg_tuple)
### cleanup to avoid redundant coercions to/from Python types
def visit_PyTypeTestNode(self, node):
"""Flatten redundant type checks after tree changes.
"""
......@@ -763,6 +765,55 @@ class OptimizeBuiltinCalls(Visitor.EnvTransform):
return node
return node.arg
def visit_CoerceFromPyTypeNode(self, node):
"""Drop redundant conversion nodes after tree changes.
Also, optimise away calls to Python's builtin int() and
float() if the result is going to be coerced back into a C
type anyway.
"""
self.visitchildren(node)
arg = node.arg
if not arg.type.is_pyobject:
# no Python conversion left at all, just do a C coercion instead
if node.type == arg.type:
return arg
else:
return arg.coerce_to(node.type, self.env_stack[-1])
if not isinstance(arg, ExprNodes.SimpleCallNode):
return node
if not (node.type.is_int or node.type.is_float):
return node
function = arg.function
if not isinstance(function, ExprNodes.NameNode) \
or not function.type.is_builtin_type \
or not isinstance(arg.arg_tuple, ExprNodes.TupleNode):
return node
args = arg.arg_tuple.args
if len(args) != 1:
return node
func_arg = args[0]
if isinstance(func_arg, ExprNodes.CoerceToPyTypeNode):
func_arg = func_arg.arg
elif func_arg.type.is_pyobject:
# play safe: Python conversion might work on all sorts of things
return node
if function.name == 'int':
if func_arg.type.is_int or node.type.is_int:
if func_arg.type == node.type:
return func_arg
elif node.type.assignable_from(func_arg.type) or func_arg.type.is_float:
return ExprNodes.CastNode(func_arg, node.type)
elif function.name == 'float':
if func_arg.type.is_float or node.type.is_float:
if func_arg.type == node.type:
return func_arg
elif node.type.assignable_from(func_arg.type) or func_arg.type.is_float:
return ExprNodes.CastNode(func_arg, node.type)
return node
### dispatch to specific optimisers
def _find_handler(self, match_name, has_kwargs):
call_type = has_kwargs and 'general' or 'simple'
handler = getattr(self, '_handle_%s_%s' % (call_type, match_name), None)
......
cimport cython
@cython.test_assert_path_exists("//SingleAssignmentNode/CastNode")
@cython.test_fail_if_path_exists("//SimpleCallNode")
def double_to_short_int(double x):
"""
>>> double_to_short_int(4.1)
4
>>> double_to_short_int(4)
4
"""
cdef short r = int(x)
return r
@cython.test_assert_path_exists("//SingleAssignmentNode/CastNode")
@cython.test_fail_if_path_exists("//SimpleCallNode")
def double_to_pyssizet_int(double x):
"""
>>> double_to_pyssizet_int(4.1)
4
>>> double_to_pyssizet_int(4)
4
"""
cdef Py_ssize_t r = int(x)
return r
@cython.test_assert_path_exists("//SingleAssignmentNode/CastNode")
@cython.test_fail_if_path_exists("//SimpleCallNode")
def double_to_pyssizet_float(double x):
"""
>>> double_to_pyssizet_int(4.1)
4
>>> double_to_pyssizet_int(4)
4
"""
cdef Py_ssize_t r = float(x)
return r
@cython.test_assert_path_exists("//SingleAssignmentNode/CastNode")
@cython.test_fail_if_path_exists("//SimpleCallNode")
def int_to_short_int(int x):
"""
>>> int_to_short_int(4)
4
"""
cdef short r = int(x)
return r
@cython.test_assert_path_exists("//SingleAssignmentNode/CastNode")
@cython.test_fail_if_path_exists("//SimpleCallNode")
def short_to_float_float(short x):
"""
>>> short_to_float_float(4)
4.0
"""
cdef float r = float(x)
return r
@cython.test_assert_path_exists("//SingleAssignmentNode/CastNode")
@cython.test_fail_if_path_exists("//SimpleCallNode")
def short_to_double_float(short x):
"""
>>> short_to_double_float(4)
4.0
"""
cdef double r = float(x)
return r
@cython.test_assert_path_exists("//SingleAssignmentNode/CastNode")
@cython.test_fail_if_path_exists("//SimpleCallNode")
def short_to_double_int(short x):
"""
>>> short_to_double_int(4)
4.0
"""
cdef double r = int(x)
return r
@cython.test_fail_if_path_exists("//SimpleCallNode",
"//SingleAssignmentNode/CastNode")
def float_to_float_float(float x):
"""
>>> 4.05 < float_to_float_float(4.1) < 4.15
True
>>> float_to_float_float(4)
4.0
"""
cdef float r = float(x)
return r
@cython.test_fail_if_path_exists("//SimpleCallNode",
"//SingleAssignmentNode/CastNode")
def double_to_double_float(double x):
"""
>>> 4.05 < double_to_double_float(4.1) < 4.15
True
>>> double_to_double_float(4)
4.0
"""
cdef double r = float(x)
return r
# tests that cannot be optimised
@cython.test_fail_if_path_exists("//SingleAssignmentNode/CastNode")
@cython.test_assert_path_exists("//SimpleCallNode")
def double_to_py_int(double x):
"""
>>> double_to_py_int(4.1)
4
>>> double_to_py_int(4)
4
"""
return int(x)
@cython.test_fail_if_path_exists("//SingleAssignmentNode/CastNode")
@cython.test_assert_path_exists("//SimpleCallNode")
def double_to_double_int(double x):
"""
>>> double_to_double_int(4.1)
4.0
>>> double_to_double_int(4)
4.0
"""
cdef double r = int(x)
return r
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