Message189504
A trivial optimization can be made in ``pow(a, b, c)``
if ``b`` is even and ``c - a < a``
```
In [1]: c = (1 << 1000000) + 1
In [2]: a = c - 1234567
In [3]: b = 2
In [4]: %timeit pow(a, b, c)
1 loops, best of 3: 3.03 s per loop
In [5]: %timeit pow(c - a if c - a < (a >> 10) else a, b, c)
1000 loops, best of 3: 287 us per loop
```
This optimization is probably done in GMP, since using gmpy.mpz
[5] is a bit slower than [4]. |
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Date |
User |
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2013-05-18 10:07:19 | pernici | set | recipients:
+ pernici |
2013-05-18 10:07:19 | pernici | set | messageid: <1368871639.93.0.89718215484.issue18005@psf.upfronthosting.co.za> |
2013-05-18 10:07:19 | pernici | link | issue18005 messages |
2013-05-18 10:07:19 | pernici | create | |
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