[Python-Dev] int/float freelists vs pymalloc

Christian Heimes lists at cheimes.de
Fri Feb 8 19:54:41 CET 2008


Andrew MacIntyre wrote:
> However, my tests do show that something is funny with the current
> freelist implementation for floats on at least 2 platforms, and that
> doing without that sort of optimisation for float objects would likely
> not be a hardship with PyMalloc.

float objects are slightly larger than int objects. On a 32bit OS both
have ob_type pointer of size 4, a ref counter of size 4. But an int
object has a value of type long with 4 bytes and a float stores its
value in a double with size 8.

I assume that the difference in size leads to a different allocation timing.

Christian





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