This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: What is wrong with Bugzilla? [Was: Re: GCC and Floating-Point]
Vincent Lefevre <vincent+gcc@vinc17.org> writes:
> On 2005-05-31 22:11:36 +0200, Andreas Schwab wrote:
>> Vincent Lefevre <vincent+gcc@vinc17.org> writes:
>> > On 2005-05-31 21:16:19 +0200, Andreas Schwab wrote:
>> >> Vincent Lefevre <vincent+gcc@vinc17.org> writes:
>> >> > The "long double" type is required, but it is not required to be
>> >> > extended precision.
>> >>
>> >> But it can be.
>> >
>> > So what?
>>
>> You can take advantage of it if it exists (which you can find out about
>> portably). But not if your compiler has crippled it.
>
> You're wrong. If it is written in a portable way, the program will
> still work if the processor rounds in double precision.
You are mistaken.
#include <assert.h>
#include <float.h>
long double one = 1.0;
long double one_plus_eps;
int
main (void)
{
long double one_plus_eps;
one_plus_eps = one + LDBL_EPSILON;
assert (one != one_plus_eps);
return 0;
}
Andreas.
--
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."