Re: RFA: correct size of long double on PPC Linux

[Kevin Buettner <kevinb@redhat.com>]

On 26 Mar 2004 10:45:13 -0500
Jim Blandy <jimb@redhat.com> wrote:

> Daniel Jacobowitz <drow@false.org> writes:
> 
> > On Thu, Mar 25, 2004 at 10:23:58PM -0700, Kevin Buettner wrote:
> > > On 24 Mar 2004 13:10:33 -0500
> > > Jim Blandy <jimb@redhat.com> wrote:
> > > 
> > > > 2004-03-24  Jim Blandy  <jimb@redhat.com>
> > > > 
> > > > 	* ppc-linux-tdep.c (ppc_linux_init_abi): Long doubles are eight
> > > > 	bytes long on PPC Linux.
> > > 
> > > Can you provide the ABI reference for this?
> > > 
> > > According to the documentation that I have (which is the System V ABI
> > > PowerPC Processor Supplement), the size of a long double is 16 bytes.
> > 
> > Yes - this is one of the known warts in the PPC GNU/Linux ABI.  People
> > have been talking for years about fixing it to match the SysV ABI.  GCC
> > only recently got 128-bit long double support on PPC, so it may be
> > changing soon; but for all existing PPC GNU/Linux systems I know of,
> > eight bytes is correct.
> 
> I went to the Linux Standards Base, and it said that programs that use
> 'long double' on PPC Linux are non-conformant.  So I figured the best
> I could do was to make GDB match GCC.

Okay, this patch is approved then, so long as you add a suitable comment
about PPC Linux deviating from the System V ABI on this matter.

Thanks!

Kevin