[Mesa-dev] About tests for extensions that are later integrated in the core specs

[Matt Turner]

On Fri, Mar 4, 2016 at 6:50 AM, Andres Gomez <agomez at igalia.com> wrote:
> Hi,
>
> as complementary work to the one done to "Add FP64 support to the i965
> shader backends" at:
> https://bugs.freedesktop.org/show_bug.cgi?id=92760
>
> We've been working to add piglit tests that would check the new features
> added by this addition. Because of this, we have created several
> generators.
>
> Checking other generators that also apply to fp64, we have seen that
> those generate "duplicated" tests for:
>       * glsl-4.00
>       * arb_gpu_shader_fp64
>
> Probably, this makes sense but we are also seeing that individual tests
> that are coded for the extension at:
>       * tests/spec/arb_gpu_shader_fp64
>
> Do not have a counterpart at:
>       * tests/spec/glsl-4.00
>
> So, the question would be, when doing tests for an extension:
>       * Should we make the generators create "duplicated" tests for the
>         extension and for the glsl version that takes the features of
>         the extension into the core? Our guess is, "yes".

Right, since it's usually trivial to make the generator scripts
produce tests for multiple APIs, we do it.

>       * Should we duplicate also the individual tests in the same way?
>         Our guess is, again, "yes", but we do not know if this would be
>         too overkill.

We don't usually duplicate non-generated tests. There's usually not
any chance of a feature working in one API but not the other.

One case where we do sometimes duplicate non-generated tests for
equivalent functionality is Desktop GL vs ES, partly because the
equivalent functionality is often provided by different extensions
between the APIs.

So to answer your main question, I would generate tests for both
glsl-4.00 and arb_gpu_shader_fp64, but only manually write tests for
arb_gpu_shader_fp64.