[Numpy-discussion] UInt64 is not supported on 64-bit architecture?
Todd Miller
jmiller at stsci.edu
Tue Mar 18 11:10:30 CST 2003
Francesc Alted wrote:
>A Dimarts 18 Març 2003 18:24, Todd Miller va escriure:
>
>
>>That's great to hear! Incidentally, you should probably also set LP64
>>to 1. That asserts that a Python integer (a C long) is 64-bits and
>>makes the default array integer type Int64 rather than Int32. I don't
>>know anything about SGI, but you can determine if LP64 is appropriate
>>by looking at sys.maxint: 2-billionish is 32-bit, 9-gazillionish is
>>64-bit.
>>
>>
>
>Well, to say the truth, I've already tested that, but it gave me some weird
>errors with the Numeric compatibility tests included in PyTables. In
>particular, it seems to make a difference between the "l" (long) and "i"
>(int) typecodes, that make the tests to fail (maybe I should investigate
>this more, but I'm short of time lately).
>
That sounds consistent with my understanding of LP64. C longs and
pointers are 64-bit, while C ints remain 32-bit. Hence, for LP64, 'i'
and 'l' should be different. That is not to say numarray has it's act
totally together here; LP64 is rather confusing, as is the fact that a
Python Int is actually a C long.
For now, I'll just apply your patch as-is.
>
>
Regards,
Todd
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