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Re: -malign-double


> 
> Jan could you please add this back into 3.1.1 too?  Technically, it is a
> regression.
It has been done by Geoff already.
Thanks..

Honza
> 
> Kelley Cook
> 
> 
> 
> 
> 
> Jan Hubicka <jh@suse.cz> on 05/15/2002 04:37:20 AM
> 
> To:    Kelley Cook <kelley.r.cook@gm.com>
> cc:    Jan Hubicka <jh@suse.cz>, gcc@gcc.gnu.org, David Ronis
>        <ronis@ronispc.chem.mcgill.ca>, gcc-patches@gcc.gnu.org
> Subject:    Re: -malign-double
> 
> 
> > >Sorry to be a pest, but nobody answered this the last time I asked:
> > >
> > >I've just noticed that the 3.1 documentation for the -malign-double
> > >flag no longer contain the warning about structures; i.e., it used to
> > >read:
> > >
> > >
> > >-malign-double'
> > >`-mno-align-double'
> > > Control whether GCC aligns `double', `long double', and `long
> > > long' variables on a two word boundary or a one word boundary.
> > > Aligning `double' variables on a two word boundary will produce
> > > code that runs somewhat faster on a `Pentium' at the expense of
> > > more memory.
> > >
> > > *Warning:* if you use the `-malign-double' switch, structures
> > > containing the above types will be aligned differently than the
> > > published application binary interface specifications for the 386.
> > >
> > >I'd been burned badly by not paying attention to this in the past.
> > >
> > >What is the current situation?
> > >
> > >David
> >
> > It disappeared during the checkin of this patch
> >
> >
> http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/Attic/invoke.texi.diff?r1=1.252&r2=1.253
> 
> >
> > But the corresponding patch posted to gcc-patches
> >
> > http://gcc.gnu.org/ml/gcc-patches/2000-12/msg00719.html
> >
> > doesn't mention this.
> I am installing the attached patch to the mainline as obvious.
> 
> Wed May 15 10:33:54 CEST 2002  Jan Hubicka  <jh@suse.cz>
> 
>  * invoke.texi (-malign-double): Re-add lost warning.
> 
> Index: doc/invoke.texi
> ===================================================================
> RCS file: /cvs/gcc/egcs/gcc/doc/invoke.texi,v
> retrieving revision 1.100
> diff -c -3 -p -r1.100 invoke.texi
> *** doc/invoke.texi     8 Jan 2002 19:59:50 -0000     1.100
> --- doc/invoke.texi     15 May 2002 08:33:43 -0000
> *************** boundary.  Aligning @code{double} variab
> *** 7596,7601 ****
> --- 7596,7605 ----
>   produce code that runs somewhat faster on a @samp{Pentium} at the
>   expense of more memory.
> 
> + @strong{Warning:} if you use the @samp{-malign-double} switch,
> + structures containing the above types will be aligned differently than
> + the published application binary interface specifications for the 386.
> +
>   @item -m128bit-long-double
>   @opindex m128bit-long-double
>   Control the size of @code{long double} type. i386 application binary
>   interface
> 
> 
> 


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