Re: What about big integers in Ada 2005?

[Brian May <bam@snoopy.apana.org.au>]

>>>>> "Martin" == Martin Krischik <krischik@users.sourceforge.net> writes:

    Martin> You are mistaken here. i.E GNAT supports 64 integers for
    Martin> 32 bit CPUs. It's all up to the particular compiler. In
    Martin> theory you could create an Ada compiler which supports
    Martin> intergers up to the memory limit - it would still conform
    Martin> to the standart.

Question (from writing a communications protocol with a high level
programming language that turned out to a an extremely poor
choice[1]):

Does GNAT support both "unsigned" and "signed" 64 bit numbers on 32
bit CPUs?

The reason I ask is because the protocol specs say some numbers might
be 64 bit, and sometimes they are signed, and other times that might
be unsigned. I am just curious if how well Ada could cope with this.

Notes:

[1] PHP. As far as I can tell it only supports signed 32 bit numbers
on 32 bit platforms[1].

[2] Fortunately, 32 bit numbers are probably OK for my client. This is
kind of ugly though, as I have to store the numbers in a mysql
database (signed/unsigned up to 64 bit[3]). My current approach is to
turn it into a positive number and store it in an unsigned 64 bit
field, with another field to indicate that the number is
negative. Unfortunately, the negative number 8000 0000 (hex) can't be
represented as a positive number in a signed 32 bit integer :-(.  So I
transform the number into 7FFF FFFF (hex) instead. This results in it
being out by one.

[3] Yes, even though the current code doesn't support 64bit, I have
designed the database to support it properly.
-- 
Brian May <bam@snoopy.apana.org.au>