Re: PATCH: Add -n option to i386 assembler

["H. J. Lu" <hjl at lucon dot org>]

On Tue, Jun 10, 2003 at 11:06:05AM +0930, Alan Modra wrote:
> On Mon, Jun 09, 2003 at 10:09:59AM -0700, H. J. Lu wrote:
> > +* A new command line option for the i386 assembler, -n,  will turn off
> > +  code alignment optimization.
> 
> "turn off code alignment optimization" doesn't really say what this
> switch does.  I suggest:
> 
> * Added -n switch for x86 assembler.  By default, x86 GAS replaces
>   multiple nop instructions used for alignment within code sections with
>   multi-byte nop instructions such as leal 0(%esi,1),%esi.  This switch
>   disables the optimization.
> 
> > +extern int optimize_align_code;
> > +
> >  #define md_do_align(n, fill, len, max, around)				\
> >  if ((n) && !need_pass_2							\
> > -    && (!(fill) || ((char)*(fill) == (char)0x90 && (len) == 1))		\
> > +    && (!(fill)								\
> > +	|| (optimize_align_code						\
> > +	    && (char)*(fill) == (char)0x90				\
> > +	    && (len) == 1))						\
> >      && subseg_text_p (now_seg))						\
> >    {									\
> >      frag_align_code ((n), (max));					\
> 
> Looks wrong to me.  Surely optimize_align_code should affect the
> !(fill) case too?  You should also fix the formatting.
> 
> > --- gas/doc/c-i386.texi.nop	2001-03-09 11:17:14.000000000 -0800
> > +++ gas/doc/c-i386.texi	2003-06-09 09:55:10.000000000 -0700
> > @@ -61,6 +61,10 @@ These options are only available with th
> >  require that the necessary BFD support has been included (on a 32-bit
> >  platform you have to add --enable-64-bit-bfd to configure enable 64-bit
> >  usage and use x86-64 as target platform).
> > +
> > +@item -n
> > +When this option is used, code alignment optimization will be turned
> > +off.
> >  @end table
> >  
> >  @node i386-Syntax
> 
> Use the expanded description here too.
> 

Here is the new one.

Thanks.


H.J.

Attachment: gas-i386-nop.patch
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