[Python-Dev] Optimization targets - refcount (original) (raw)

Greg Ewing greg at cosc.canterbury.ac.nz
Sun Apr 18 05:23:15 EDT 2004

"Phillip J. Eby" <pje at telecommunity.com>:

I'm not sure, however, that this would be common enough to be helpful. It seems to me PyINCREF should effectively translate to only a single machine instruction or two.

On a RISC architecture, probably 3 instructions -- load, increment, store.

It's the memory accesses that will be the most expensive part of this. But then, if increfing Py_None is really that common, its refcount will likely be in cache.

I doubt whether it really is very common, though, compared to increfs of all other objects.

Greg Ewing, Computer Science Dept, +--------------------------------------+ University of Canterbury, | A citizen of NewZealandCorp, a | Christchurch, New Zealand | wholly-owned subsidiary of USA Inc. | greg at cosc.canterbury.ac.nz +--------------------------------------+

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