Re: [PATCH] Revert "cross-canadian: Handle powerpc linux verses linux-gnuspe"

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Fri, 2014-01-31 at 17:53 +0000, alexandru.sardan@freescale.com wrote:
> Hi Richard,
> 
> I've tested your patch for both altivec and spe and it works fine.

Would you be able to put together a proper patch with the explanation
and so on so we can get it merged and resolve this issue?

Cheers,

Richard

> Regards,
> Alex
> 
> > -----Original Message-----
> > From: Richard Purdie [mailto:richard.purdie@linuxfoundation.org]
> > Sent: Wednesday, January 29, 2014 1:39 PM
> > To: Phil Blundell
> > Cc: Sardan Alexandru Cezar-B41700; Udma Catalin-Dan-B32721; openembedded-
> > core@lists.openembedded.org
> > Subject: Re: [OE-core] [PATCH] Revert "cross-canadian: Handle powerpc
> > linux verses linux-gnuspe"
> > 
> > On Fri, 2014-01-24 at 20:56 +0000, Phil Blundell wrote:
> > > On Thu, 2014-01-23 at 18:22 +0000, alexandru.sardan@freescale.com
> > wrote:
> > > > [Alex Sardan] No. The more generic target powerpc-none-linux will not
> > > > generate SPE code and the powerpc-none-linux-gnuspe target that
> > generates
> > > > SPE will not be able to generate Altivec.
> > >
> > > Why not?  As far as I can tell from the gcc configury, the target
> > string
> > > only affects the defaults (i.e. powerpc-*-linux gets -mno-spe
> > > -mno-altivec, powerpc-*-linuxaltivec gets -maltivec -mno-spec, and
> > > powerpc-*-linuxspe gets -mno-altivec -mspe).  There doesn't seem to be
> > > any real impact beyond this that would make the compiler binary
> > > fundamentally incapable of generating either type of instruction if you
> > > pass the appropriate options on the command line.
> > 
> > I had a closer look at this. The config.gcc case statements for powerpc
> > only appear to let you include rs6000/linuxaltivec.h or
> > rs6000/linuxspe.h, there doesn't appear to be a target you can pass in
> > to get both.
> > 
> > Looking at the code in those files, I don't see any reason why you can't
> > actually include support for both however. As such, I just hacked a
> > build with:
> > 
> > tm_file="${tm_file} rs6000/linuxaltivec.h"
> > tm_file="${tm_file} rs6000/linuxspe.h rs6000/e500.h"
> > 
> > and it certainly seems to build ok and compile things (this was just for
> > qemuppc). I didn't try building altivec or spe specific things but
> > looking at the code, I can't see any reason it wouldn't work at least in
> > theory.
> > 
> > I'd suggest the easiest way to resolve this may be to patch gcc to
> > include support for all the modes.
> > 
> > Cheers,
> > 
> > Richard
> > 
> > 
> 
>