RE: [PATCH][GCC][Testsuite][ARM][AArch64] Enable Dot Product for generic tests for ARM and AArch64 [Patch (7/8)]

[Tamar Christina <Tamar dot Christina at arm dot com>]

> -----Original Message-----
> From: Richard Earnshaw (lists) [mailto:Richard.Earnshaw@arm.com]
> Sent: 12 October 2017 14:21
> To: Tamar Christina; James Greenhalgh
> Cc: gcc-patches@gcc.gnu.org; nd; Marcus Shawcroft
> Subject: Re: [PATCH][GCC][Testsuite][ARM][AArch64] Enable Dot Product
> for generic tests for ARM and AArch64 [Patch (7/8)]
> 
> On 06/10/17 13:45, Tamar Christina wrote:
> > Hi All,
> >
> > this is a respin with the changes suggested. Note that this patch is no 8/8 in
> the series.
> >
> > Regtested on arm-none-eabi, armeb-none-eabi, aarch64-none-elf and
> > aarch64_be-none-elf with no issues found.
> >
> > Ok for trunk?
> >
> > gcc/testsuite
> > 2017-10-06  Tamar Christina  <tamar.christina@arm.com>
> >
> >         * gcc.dg/vect/vect-reduc-dot-s8a.c
> >         (dg-additional-options, dg-require-effective-target): Add +dotprod.
> >         * gcc.dg/vect/vect-reduc-dot-u8a.c
> >         (dg-additional-options, dg-require-effective-target): Add +dotprod.
> > ________________________________________
> > From: Tamar Christina
> > Sent: Monday, September 4, 2017 12:35:39 PM
> > To: James Greenhalgh
> > Cc: gcc-patches@gcc.gnu.org; nd; Richard Earnshaw; Marcus Shawcroft
> > Subject: RE: [PATCH][GCC][Testsuite][ARM][AArch64] Enable Dot Product
> > for generic tests for ARM and AArch64 [Patch (7/8)]
> >
> >> I'm surprised that this worked!
> >>
> >> It looks like you unconditionally add the -march=armv8.2-a+dotprod
> >> options, which should cause you to generate instructions which will
> >> not execute on targets which don't support this instruction. As far
> >> as I can see, this is an execute test, so that should cause undefined
> >> instruction exceptions on an Armv8-A target at the very least.
> >
> > It's not, there is no dg-do specified, which means it defaults to "compile"
> > This is a straight compilation tests that checks to see if the target
> > can do the reduction. There may be a main, but it's never executed,
> > which is why I don't have a hardware check against it.
> >
> > The unconditional armv8.2+dotprod is for this reason. It doesn't matter
> what hardware.
> >
> >>
> >> So, not OK in its current form.
> >>
> >> Thanks,
> >> James
> >>
> >>>
> >>> Ok for trunk?
> >>>
> >>> gcc/testsuite
> >>> 2017-09-01  Tamar Christina  <tamar.christina@arm.com>
> >>>
> >>>     * gcc.dg/vect/vect-reduc-dot-s8a.c
> >>>     (dg-additional-options, dg-require-effective-target): Add +dotprod.
> >>>     * gcc.dg/vect/vect-reduc-dot-u8a.c
> >>>     (dg-additional-options, dg-require-effective-target): Add +dotprod.
> >>>
> >>> --
> >
> 
> iff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-s8a.c
> b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-s8a.c
> index
> dc4f52019d5435edbbc811b73dee0f98ff44c1b1..acb6862f8274fb954f69bd45e8
> edeedcdca4cbf7
> 100644
> --- a/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-s8a.c
> +++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-dot-s8a.c
> @@ -1,4 +1,7 @@
>  /* { dg-require-effective-target vect_int } */
> +/* { dg-require-effective-target arm_v8_2a_dotprod_neon_hw { target {
> aarch64*-*-* || arm*-*-* } } } */
> 
> Why do you need hardware with dot-product if these are compile-only
> tests?  (presumably that's what the _hw at the end of the require means).

James was right in that vect.exp overrides the default from compile to run for these tests,
So they are execution tests.

> 
> R.