[Numpy-discussion] Solaris Sparc build broken

David Cournapeau david@ar.media.kyoto-u.ac...
Fri Nov 6 01:10:58 CST 2009


Charles R Harris wrote:
>
>
> On Thu, Nov 5, 2009 at 10:35 PM, David Cournapeau
> <david@ar.media.kyoto-u.ac.jp <mailto:david@ar.media.kyoto-u.ac.jp>>
> wrote:
>
>     Charles R Harris wrote:
>     > So you are going to leave us all hanging here in curiosity? What is
>     > your solution?
>
>     I had to sleep :)
>
>     The solution is based on parsing the generated binary code -
>     that's how
>     MPFR is doing it, so it has been tested in the wild. The code to
>     compile
>     is something like:
>
>     /* "before" is 16 bytes to ensure there's no padding between it
>     and "x".
>      *    We're not expecting any "long double" bigger than 16 bytes
>     or with
>      *       alignment requirements stricter than 16 bytes.  */
>     typedef long double test_type;
>
>     struct {
>            char         before[16];
>            test_type    x;
>            char         after[8];
>     } foo = {
>            { '\0', '\0', '\0', '\0', '\0', '\0', '\0', '\0',
>              '\001', '\043', '\105', '\147', '\211', '\253', '\315',
>     '\357' },
>            -123456789.0,
>            { '\376', '\334', '\272', '\230', '\166', '\124', '\062',
>     '\020' }
>     };
>
>     They compile it, parse with awk from the dump od -f.
>
>
> So the before/after bits are tags that mark the beginning/end of the
> type for the parse? Any particular reason not to use a string?
As for why not using my name, I am not that megalomaniac, at least not
yet :)

od prints a dump in octal form, so a string is not much more readable. I
am not sure why they use od instead of another dump format - but there
is value if keeping the same format as them for testing, all other
things being equal.

Anyway, the detection code is checked in in svn now, I just need to fix
universal build issue, but this should not be difficult,

David


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