[Python-checkins] r46499 - in python/trunk: Include/pyport.h Include/unicodeobject.h Objects/stringobject.c

Sun May 28 21:50:44 CEST 2006

Martin v. Löwis wrote:
>> needforspeed: added Py_MEMCPY macro (currently tuned for Visual C only),
>> and use it for string copy operations. this gives a 20% speedup on some
>> string benchmarks.
>> Shouldn't this better use
>> #pragma intrinsic(memcpy)

in theory, yes. but in practice, things look a bit different, at least 
on this machine (using visual studio .net 2003 enterprise):
 43.2 intrinsic memcpy
 43.4 memcpy
 39.1 Py_MEMCPY as in trunk
 39.2 Py_MEMCPY + intrinsic memcpy
(using one of the stringbench replace benchmarks, best of 3 runs on a 
T2300 dual core)
sure looks like memcpy is always intrinsic.
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