[Patches] [ python-Patches-517521 ] Optimization for PyObject_Get/SetAttr

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Patches item #517521, was opened at 2002-02-15 01:19
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Category: Core (C code)
Group: Python 2.2.x
Status: Open
Resolution: None
Priority: 5
Submitted By: Greg Chapman (glchapman)
Assigned to: Nobody/Anonymous (nobody)
Summary: Optimization for PyObject_Get/SetAttr

Initial Comment:
The attached patch is based on the assumption that the 
vast majority of calls to PyObject_GetAttr and 
PyObject_SetAttr use a PyString (rather than a 
PyUnicode) as the name parameter.  Because these 
routines perform a PyUnicode_Check first, every call 
(with a PyString as name) requires a call to 
PyType_IsSubType.  By reorganizing so that 
PyString_Check is called first, the call to 
PyType_IsSubType is avoided in the common case.  The 
same reorganization is done for 
PyObject_GenericGet/SetAttr.



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>Comment By: Andrew I MacIntyre (aimacintyre)
Date: 2002-03-15 18:18

Message:
Logged In: YES 
user_id=250749

I've tried this patch and it appears to have no ill affects 
on a FreeBSD 4.4 system, though I haven't exhaustively 
checked it.

My testing (using pystone.py and PyBench 1.0) shows only 
about 2% gain, which in isolation is hardly worth the 
bother (though a number of 2% gains can cumulatively be 
attactive).

I don't know at this point whether PEP 263 (if accepted) 
would have any affect on the change implemented by the 
patch; if so, it may not be worth pursuing.


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Comment By: Andrew I MacIntyre (aimacintyre)
Date: 2002-03-15 18:16

Message:
Logged In: YES 
user_id=250749

I've tried this patch and it appears to have no ill affects 
on a FreeBSD 4.4 system, though I haven't exhaustively 
checked it.

My testing (using pystone.py and PyBench 1.0) shows only 
about 2% gain, which in isolation is hardly worth the 
bother (though a number of 2% gains can cumulatively be 
attactive).

I don't know at this point whether PEP 263 (if accepted) 
would have any affect on the change implemented by the 
patch; if so, it may not be worth pursuing.


----------------------------------------------------------------------

You can respond by visiting: 
http://sourceforge.net/tracker/?func=detail&atid=305470&aid=517521&group_id=5470