[Intel-gfx] [PATCH xf86-video-intel] Fix build on i686

[Matt Turner]

On Wed, Feb 20, 2019 at 11:25 PM Chris Wilson <chris at chris-wilson.co.uk> wrote:
>
> Quoting Matt Turner (2019-02-21 03:23:51)
> > From: Adam Jackson <ajax at redhat.com>
> >
> > Presumably this only matters for i686 because amd64 implies sse2, but:
> >
> > BUILDSTDERR: In file included from gen4_vertex.c:34:
> > BUILDSTDERR: gen4_vertex.c: In function 'emit_vertex':
> > BUILDSTDERR: sna_render_inline.h:40:26: error: inlining failed in call to always_inline 'vertex_emit_2s': target specific option mismatch
> > BUILDSTDERR:  static force_inline void vertex_emit_2s(struct sna *sna, int16_t x, int16_t y)
> > BUILDSTDERR:                           ^~~~~~~~~~~~~~
> > BUILDSTDERR: gen4_vertex.c:308:25: note: called from here
> > BUILDSTDERR:  #define OUT_VERTEX(x,y) vertex_emit_2s(sna, x,y) /* XXX assert(!too_large(x, y)); */
> > BUILDSTDERR:                          ^~~~~~~~~~~~~~~~~~~~~~~~
> > BUILDSTDERR: gen4_vertex.c:360:2: note: in expansion of macro 'OUT_VERTEX'
> > BUILDSTDERR:   OUT_VERTEX(dstX, dstY);
> > BUILDSTDERR:   ^~~~~~~~~~
> >
> > The bug here appears to be that emit_vertex() is declared 'sse2' but
> > vertex_emit_2s is merely always_inline. gcc8 decides that since you said
> > always_inline you need to have explicitly cloned it for every
> > permutation of targets. Merely saying inline seems to do the job of
> > cloning vertex_emit_2s as much as necessary.
> >
> > So to reiterate: if you say always-inline, it won't, but if you just say
> > maybe inline, it will. Thanks gcc, that's helpful.
>
> Hasn't this bug occurred in gcc at least twice before?
> -Chris

Looks like some problems that are at least similar have been reported
and fixed in the past. For example:

https://patchwork.kernel.org/patch/6266711/

It appears that Fedora has some other always-inline related patches as well:

https://src.fedoraproject.org/rpms/xorg-x11-drv-intel/blob/master/f/0001-Fix-build-on-F28-and-later.patch
https://src.fedoraproject.org/rpms/xorg-x11-drv-intel/blob/master/f/intel-gcc-pr65873.patch

GCC PR65873 (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65873) is
titled "Failure to inline always_inline memcpy"...