Re: [PATCH] FreeBSD arm support, EABI.

[Andreas Tobler <andreast-list at fgznet dot ch>]

Hi Richard,

On 07.11.14 14:45, Richard Earnshaw wrote:
> On 02/11/14 22:11, Andreas Tobler wrote:
> > Hello all,
> >
> > this is a patch which brings support for arm*-*-freebsd* to trunk.
> > The architectures supported are arm-*-*freebsd*, armv6-*-freebsd* and
> > armv6hf-*-freebsd*.
> > armv6 stands for ARM_ARCH == 6, arm stands for ARM_ARCH < 6.
> >
> > There is kernel development for armv8 aka. aarch64 ongoing but this is
> > not covered here. This patch only covers 32-bit arm in a basic manner.
> >
> > The patch is built and tested against armv6, armv6hf and arm. The former
> > two tests (lots of) were done on a WANDBOARD-QUAD, the latter on a
> > MARVELL board with 256MB Ram and 200MHz cpu.... (around 72h+ for a build
> > and test.....)
> >
> > Results for armv6hf are on the list. Only one entry but locally I ran
> > several dozens runs...
> >
> > Once if this patch is accepted a few test suite additions will follow.
> > (arm*-*-*eabi* -> arm_eabi)
> >
> > The patch itself is also prepared for arm*eb*-*-freebsd*, but I could
> > not test since I lack the HW.

[snip]

> This mostly looks OK, but a couple of nits.

Thank you for the review.

> > Index: gcc/config/arm/arm.c
> > ===================================================================
> > --- gcc/config/arm/arm.c	(revision 217020)
> > +++ gcc/config/arm/arm.c	(working copy)
> > @@ -2202,7 +2202,11 @@
> >   {
> >     /* For Linux, we have access to kernel support for atomic operations.  */
> >     if (arm_abi == ARM_ABI_AAPCS_LINUX)
> > +#ifndef __FreeBSD__
> >       init_sync_libfuncs (2 * UNITS_PER_WORD);
> > +#else
> > +    init_sync_libfuncs (UNITS_PER_WORD);
> > +#endif
>
> This would be better handled by some refactoring, so that we can
> eliminate the conditionalized code in the main function.  Define
> something like MAX_SYNC_LIBFUNC_SIZE and then override it in the
> FreeBSD-specific header.

Done.

> > @@ -3036,6 +3040,9 @@
> >         warning (0, "target CPU does not support unaligned accesses");
> >         unaligned_access = 0;
> >       }
> > +#ifdef __FreeBSD__
> > +      unaligned_access = 0;
> > +#endif
>
> This really should be fixed in the OS; you're not really supporting the
> architecture properly if you don't allow this on v6 or later.  In the
> mean time, the code should be moved to SUBTARGET_OVERRIDE_OPTIONS.

Agreed, for now as you suggested included it in the 
SUBTARGET_OVERRIDE_OPTIONS of config/arm/freebsd.h

> > Index: gcc/config/arm/freebsd.h
> > ===================================================================
> > --- gcc/config/arm/freebsd.h	(revision 0)
> > +++ gcc/config/arm/freebsd.h	(working copy)
>
> > +
> > +/*  Use the AAPCS type for wchar_t, override the one from config/freebsd.h.  */
> > +#undef  WCHAR_TYPE
> > +#define WCHAR_TYPE (TARGET_AAPCS_BASED ? "unsigned int" : "long int")
>
> I don't think you should really be targeting anything that is not AAPCS
> based; so this should surely collapse to 'unsigned int'.

Done.

Attached the revised version with adapted Changelog (thanks Gerald).
Bootstraped and tested (results sent).

Ok for trunk?

Thanks again for your time.
Andreas

toplevel:

2014-11-08  Andreas Tobler  <andreast@gcc.gnu.org>

        * configure.ac: Don't add ${libgcj} for arm*-*-freebsd*.
        * configure: Regenerate.

gcc:
2014-11-08  Andreas Tobler  <andreast@gcc.gnu.org>

        * config.gcc (arm*-*-freebsd*): New configuration.
        * config/arm/freebsd.h: New file.
        * config.host: Add extra components for arm*-*-freebsd*.
        * config/arm/arm.h: Introduce MAX_SYNC_LIBFUNC_SIZE.
        * config/arm/arm.c (arm_init_libfuncs): Use MAX_SYNC_LIBFUNC_SIZE.


libgcc:
2014-11-08  Andreas Tobler  <andreast@gcc.gnu.org>

        * config.host (arm*-*-freebsd*): Add new configuration for
        arm*-*-freebsd*.
        * config/arm/freebsd-atomic.c: New file.
        * config/arm/t-freebsd: Likewise.
        * config/arm/unwind-arm.h: Add __FreeBSD__ to the list of
        'PC-relative indirect' OS's.


libstdc++-v3:
2014-11-08  Andreas Tobler  <andreast@gcc.gnu.org>

        * configure.host: Add arm*-*-freebsd* port_specific_symbol_files.

Attachment: gcc5_fbsd_arm_20141109-1.diff
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