Irix6 long doubles implemented wrong? (27_io/ostream_inserter_arith)

Alexandre Oliva aoliva@redhat.com
Mon Jan 13 05:17:00 GMT 2003


On Jan  8, 2003, Richard Henderson <rth@redhat.com> wrote:

> On Wed, Jan 08, 2003 at 03:17:49PM -0200, Alexandre Oliva wrote:
>> I've no idea of what LIA-1 is, but it does have as many denormal bits
>> as normal bits, it's just that the minimum exponent for a denormal is
>> higher than that of a plain doubles, since denormals start with the
>> higher double still being normal.

> Huh?  No it doesn't.  The minimum normalized double-double is
> { DBL_MIN_FLT, 0 }.

Nevermind, I was thinking having a denormal in the lower double would
make the whole thing denormal, but in this case the lower double
definitely isn't denormal.

Anyway, without this hunk, we get an incorrect DENORM_MIN, and tests
fail.  DENORM_MIN isn't as low as MIN_FLT / 2**106, and that's the
problem.  This was the cleanest way I found to introduce the
possibility of having fewer denorm bits than mantissa bits, which is
exactly the case of this FP format.

Any better suggestions on how to accomplish this?  I think claiming we
don't have denormals is not the right answer either.

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                 aoliva@{redhat.com, gcc.gnu.org}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist                Professional serial bug killer



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