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On Jun 24, 2013, at 4:07 AM, Victor Stinner <victor.stinner@gmail.com> wrote:

Out of curiosity, do you know (remember) how was the number 62 chosen?

Is it a compromise between memory usage and performances? 62 is

surprising because it is not a power of two :-)

Is it to just have 64 (2+62) pointers in the structure?�

Yes, the goal was to have the struct size be an exact multiple

of the cache line length (always a power-of-two, typically 64 bytes).

What was different then is that deques weren't indexable.

When indexing was added, the size of 62 became an�

unfavorable�choice because it made the division and�modulo�

calculation�in deque\_index() slower than�for a power of two.