Hi, Raymond Hettinger wrote a micro benchmark script for comparing the performance of basic attribute and item access patterns across Python versions and build configurations, so I tested the initially committed version with Cython.
https://github.com/python/cpython/blob/master/Tools/scripts/var_access_benchmark.py Results are below, comparing Cython (master) to CPython 3.8 (master), and also disabling all C-time optimisations via the "CYTHON_*" macros (no-opt). Some things to note: - Most operations in Cython are around 30-50% faster. - C-level things like local variables are not measurable in Cython. - Setting class variables is very slow in both CPython and Cython, probably for the same (unknown) reason, maybe the method cache or so. https://bugs.python.org/issue36012 - The dict version check for Python globals is worth it. Disabling it in Cython with "-DCYTHON_USE_DICT_VERSIONS=0" slows down the lookup by 5x (2.2ns -> 10ns). - Disabling PyList optimisations with "-DCYTHON_USE_PYLIST_INTERNALS=0" slows down the "list_append_pop" benchmark by 5x (21ns -> 102ns). - The list append/pop optimisations seem to slow down non-lists unproportionally, for deques by 3x compared to CPython. That seems worth improving. Stefan CPython 3.8 (63fa1cfece) ======================== Variable and attribute read access: 5.4 ns read_local 6.0 ns read_nonlocal 15.7 ns read_global 23.5 ns read_builtin 23.1 ns read_classvar_from_class 20.4 ns read_classvar_from_instance 31.5 ns read_instancevar 25.4 ns read_instancevar_slots 23.8 ns read_namedtuple 34.5 ns read_boundmethod Variable and attribute write access: 6.2 ns write_local 6.7 ns write_nonlocal 19.1 ns write_global 113.2 ns write_classvar 44.6 ns write_instancevar 33.0 ns write_instancevar_slots Data structure read access: 23.5 ns read_list 24.0 ns read_deque 25.6 ns read_dict Data structure write access: 26.0 ns write_list 27.1 ns write_deque 32.0 ns write_dict Stack (or queue) operations: 61.6 ns list_append_pop 53.9 ns deque_append_pop Timing loop overhead: 0.4 ns loop_overhead Cython 3.0a0 (f1eaa9c1f) ======================== Variable and attribute read access: 0.2 ns read_local 0.2 ns read_nonlocal 2.2 ns read_global 0.2 ns read_builtin 13.8 ns read_classvar_from_class 11.1 ns read_classvar_from_instance 21.3 ns read_instancevar 15.5 ns read_instancevar_slots 13.6 ns read_namedtuple 21.5 ns read_boundmethod Variable and attribute write access: 0.2 ns write_local 0.1 ns write_nonlocal 13.0 ns write_global 92.9 ns write_classvar 29.6 ns write_instancevar 16.1 ns write_instancevar_slots Data structure read access: 4.0 ns read_list 4.3 ns read_deque 16.5 ns read_dict Data structure write access: 4.3 ns write_list 6.4 ns write_deque 21.4 ns write_dict Stack (or queue) operations: 20.7 ns list_append_pop 155.4 ns deque_append_pop Timing loop overhead: 0.1 ns loop_overhead Cython 3.0a0 (no-opt) ===================== Variable and attribute read access: 0.2 ns read_local 0.2 ns read_nonlocal 15.6 ns read_global 0.2 ns read_builtin 16.1 ns read_classvar_from_class 12.1 ns read_classvar_from_instance 21.9 ns read_instancevar 16.3 ns read_instancevar_slots 14.5 ns read_namedtuple 23.8 ns read_boundmethod Variable and attribute write access: 0.2 ns write_local 0.2 ns write_nonlocal 14.2 ns write_global 99.4 ns write_classvar 35.0 ns write_instancevar 22.4 ns write_instancevar_slots Data structure read access: 5.7 ns read_list 6.1 ns read_deque 21.1 ns read_dict Data structure write access: 8.4 ns write_list 8.4 ns write_deque 24.0 ns write_dict Stack (or queue) operations: 66.4 ns list_append_pop 75.1 ns deque_append_pop Timing loop overhead: 0.2 ns loop_overhead _______________________________________________ cython-devel mailing list cython-devel@python.org https://mail.python.org/mailman/listinfo/cython-devel
