phobos unittests not passing with dmd built by clang

[Martin Nowak]

On Tue, 31 Jan 2012 18:13:29 +0100, Trass3r <un at known.com> wrote:

>> Can anyone confirm this?
>> If yes, bug in clang, dmd or phobos?
>
> Note that the dmd testsuite passes for me.

Clang behaves differently, but it's probably not a bug.

----
#include <stdio.h>
#include <math.h>

int main()
{
     long double foo = NAN;
     double a = foo;
     double b = NAN;
     double c = fabs(NAN);
     printf("%Lf %d\n", foo, (int)signbit(foo));
     printf("%f %d\n", a, (int)signbit(a));
     printf("%f %d\n", b, (int)signbit(b));
     printf("%f %d\n", c, (int)signbit(c));
}
----

double a = foo; // seems like "FSTP m64fp" doesn't preserve the sign bit

We need to fix the code in PortInitializer::PortInitializer() which relies  
on
sign preserving of NaN size conversions.