Issue 27845: Optimize update_keyword_args() function (original) (raw)

Issue27845

Created on 2016-08-23 21:44 by vstinner, last changed 2022-04-11 14:58 by admin. This issue is now closed.

Messages (3)
msg273518 - (view)	Author: STINNER Victor (vstinner) *	Date: 2016-08-23 21:44
In the review of my issue #27830 "Add _PyObject_FastCallKeywords(): pass keyword arguments as (key, value) pairs", Antoine Pitrou wrote about _PyStack_AsDict(): "It's a pity that you're doing two dict lookups per keyword argument. Another strategy would be to check that `PyDict_Size() == nk` at the end, and if not, try to find the duplicate keyword." https://bugs.python.org/review/27830/diff/18203/Objects/abstract.c#newcode2326_Objects/abstract.c:2326 In fact, I simply copied code from update_keyword_args(), helper function used by do_call() and ext_do_call() in Python/ceval.c. This function is quite old, the last major change was made in 2001: --- changeset: 15711:2481b5fe86d6 branch: legacy-trunk user: Jeremy Hylton <jeremy@alum.mit.edu> date: Wed Jan 03 23:52:36 2001 +0000 files: Python/ceval.c description: Revised implementation of CALL_FUNCTION and friends. More revision still needed. (...) --- But this change just moved code. It looks like the real code was in fact added by this change made in 2000: --- changeset: 12082:603db0d0aed1 branch: legacy-trunk user: Jeremy Hylton <jeremy@alum.mit.edu> date: Tue Mar 28 23:49:17 2000 +0000 files: Grammar/Grammar Include/opcode.h Lib/dis.py Misc/ACKS Python/ceval.c Python/compile.c Python/graminit.c description: slightly modified version of Greg Ewing's extended call syntax patch executive summary: Instead of typing 'apply(f, args, kwargs)' you can type 'f(*arg, **kwargs)'. Some file-by-file details follow. (...) ---
msg273681 - (view)	Author: STINNER Victor (vstinner) *	Date: 2016-08-25 21:45
See also the issue #27358: "BUILD_MAP_UNPACK_WITH_CALL is slow.
msg276023 - (view)	Author: STINNER Victor (vstinner) *	Date: 2016-09-12 11:42
_PyStack_AsDict() doesn't check anymore if keys are unique. BUILD_MAP_UNPACK and BUILD_MAP_UNPACK_WITH_CALL opcodes now use PyDict_Update() to combine mappings and _PyDictView_Intersect() to check if keys are unique. I don't know if there is still something to optimize. The opcode changed the method to C and Python functions (FASTCALL) changed a lot recently ;-) I suggest to close the issue.