Re: [PATCH v4 10/11] tests/tcg/s390x: Tests for Vector Enhancements Facility 2

[David Miller]

vrr is almost a perfect match (it is for this, larger than imm4 would
need to be split).

.long : this would be uglier.
use enough to be filled with nops after ?
or use a 32b and 16b instead if it's in .text it should make no difference.


On Fri, Apr 1, 2022 at 2:42 AM Christian Borntraeger
<borntraeger@linux.ibm.com> wrote:
>
>
>
> Am 01.04.22 um 04:15 schrieb David Miller:
> > Hi,
> >
> > There is some issue with instruction sub/alt encodings not matching,
> > but I worked around it easily.
> >
> > I'm dropping the updated patch for the tests in here.
> > I know I should resend the entire patch series as a higher version
> > really, and will do so.
> > I'm hoping someone can tell me if it's ok to use .insn vrr  in place
> > of vri(-d) as it doesn't match vri.
> > [https://sourceware.org/binutils/docs-2.37/as/s390-Formats.html]
> >
> > .insn doesn't deal with sub encodings and there is no good alternative
> > that I know of.
> >
> > example:
> >
> >      /* vri-d as vrr */
> >      asm volatile(".insn vrr, 0xE70000000086, %[v1], %[v2], %[v3], 0, %[I], 
> > 0\n"
> >                  : [v1] "=v" (v1->v)
> >                  : [v2]  "v" (v2->v)
> >                  , [v3]  "v" (v3->v)
> >                  , [I]   "i" (I & 7));
> >
> > Patch is attached
>
> Yes, vri sucks and does not work with vrsd. Maybe just use .long which is 
> probably
> better than using a "wrong" format.
> Opinions?