[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





More information about the Numpy-discussion mailing list