On Tue, 29 Jan 2019 10:15:00 +0200, Matti Picus wrote:
> 2000*2000*2000 overflows a 32 bit signed integer, so it wraps around to a
> negative value.
I was curious about what happens, bit-wise, in this case. We are dealing
with a signed integer, so I presume of the 33 bits in 2000**3, only 32
are kept:
In [60]: len("{0:b}".format(1999**3))
Out [60]: 33
In [61]: "{0:b}".format(1999**3)
Out [61]: '111011100000111110100110001101111'
In [62]: "{0:b}".format(1999**3)[-32:]
Out [62]: '11011100000111110100110001101111'
The first of the 32 bits indicates sign, so converting back to integer
would give:
1 * np.iinfo(np.int32).min + int('1011100000111110100110001101111', 2) ==
-601928593
Best regards,
Stéfan
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