This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: 64-bit long doubles on i386?
- From: Tim Prince <tprince at computer dot org>
- To: Hilfinger at otisco dot mckusick dot com,"Paul N. Hilfinger" <hilfingr at otisco dot mckusick dot com>, gcc at gcc dot gnu dot org
- Date: Wed, 10 Apr 2002 05:50:17 -0700
- Subject: Re: 64-bit long doubles on i386?
- References: <200204101100.EAA03606@otisco.McKusick.COM>
- Reply-to: tprince at computer dot org
On Wednesday 10 April 2002 04:00, Paul N. Hilfinger wrote:
> What would need to be done to modify GCC so that it uses only <=64-bit
> floating-point formats (so that long double and double have
> essentially the same semantics, the extended precision is not used for
> intermediate results)? I've tried the obvious modifications to i386.h and
> float-i386.h: setting
>
> #define LONG_DOUBLE_TYPE_SIZE 64
> #define MAX_LONG_DOUBLE_TYPE_SIZE 64
> #define INTEL_EXTENDED_IEEE_FORMAT 0
> #define LIBGCC2_LONG_DOUBLE_TYPE_SIZE 64
> #define INTEL_EXTENDED_IEEE_FORMAT 0
>
..............
> Why am I interested? Well, although I've been experimenting with this on
> Linux, the eventual "client" is Interix, where there is sometimes a
> "legacy" problem of compatibility with (ugh) VC.
>
............
Why don't you simply set 53-bit precision mode at run time, as currentVC
does, if you want similar operation?
--
Tim Prince