GDC release 0.23

[Sean Kelly]

Anders F Björklund wrote:
>>> GDC now supports 64-bit targets! A new x86_64 Linux binary is
>>> available and the MacOS X binary supports x86_64 and ppc64.
>>
>> Excellent news! I'll try it on ppc64 Linux too (Fedora Core)
> 
> Except for some strange (temporary?) build error with soft-float,
> it built just fine for powerpc64-unknown-linux-gnu (with FC5/PPC*)

That reminds me.  Is it really a good idea to map the GCC/PPC "long 
double" to "real" in D?  I know this has come up before:

http://www.digitalmars.com/d/archives/digitalmars/D/20790.html

and the data type seems like an aberration.  Here is some more info:

http://lists.apple.com/archives/Darwin-development/2001/Jan/msg00499.html

And from the ELF ABI:

     This "Extended precision" differs from the IEEE 754 Standard
     in the following ways:

     * The software support is restricted to round-to-nearest
       mode. Programs that use extended precision must ensure
       that this rounding mode is in effect when
       extended-precision calculations are performed.
     * Does not fully support the IEEE special numbers NaN and
       INF. These values are encoded in the high-order double
       value only. The low-order value is not significant.
     * Does not support the IEEE status flags for overflow,
       underflow, and other conditions. These flag have no
       meaning in this format.

I can't claim to have the maths background of some folks here, but this 
suggests to me that this 128-bit representation isn't truly IEEE-754 
compliant and therefore probably shouldn't be a default data type in D?


Sean