[Mesa-dev] [PATCH] glsl: Do not allow scalar types in vector relational functions

[Boyan Ding]

2016-11-05 3:23 GMT+08:00 Matt Turner <mattst88 at gmail.com>:
> On Sun, Oct 30, 2016 at 11:45 PM, Boyan Ding <boyan.j.ding at gmail.com> wrote:
>> According to OpenGL Shading Language 4.50 spec, Section 8.7 "Vector
>> Relational Functions", functions of this type do not operate on scalar
>> types, so remove scalar types from signature definitions to make the
>> behavior consistent with glslangValidator and other drivers.
>
> Yep. Looks like it's always been this way.
>
> The patch is
>
> Reviewed-by: Matt Turner <mattst88 at gmail.com>
>
> Since this seems to be untested by any suite, could you provide some
> piglit parser tests that confirm that lessThanEqual(scalar, scalar),
> et al doesn't work?
>

Thanks for the review, patch has been sent to piglit and tests pass
with this patch. Please help me push this one if you think it is
appropriate.

> Rant: what a stupid mess to require <= for scalars but lessThanEqual
> for vectors.

Yeah, I happened to find this when doing my homework. I was quite
shocked that one of my shaders, in which I somehow used
greaterThanEqual on floats to get a boolean, didn't compile on nvidia
driver until I saw the spec.

Regards,
Boyan Ding

>
> Somewhere on my todo list is a GLSL extension that fixes things like this...