[Mesa-dev] [PATCH 3/5] mesa: Fix add_index_to_name logic

[Timothy Arceri]

On Tue, 2016-05-31 at 16:45 -0700, Ian Romanick wrote:
> On 05/31/2016 02:44 PM, Timothy Arceri wrote:
> > 
> > On Tue, 2016-05-31 at 11:52 -0700, Ian Romanick wrote:
> > > 
> > > From: Ian Romanick <ian.d.romanick at intel.com>
> > > 
> > > Our piglit tests for geometry and tessellation shader inputs were
> > > incorrect.  Array shader inputs and output should have '[0]' on
> > > the
> > > end
> > > regardless of stage.  In addtion, transform feedback varyings
> > > should
> > > not.
> > Is there a spec quote for this? It doesn't seem right to me since
> > for
> > arrays of arrays would that mean we should end up with gs inputs
> > like
> > this
> Here are all the rules that I think applies:
> 
>       * For an active variable declared as an array of basic types, a
> single
>         entry will be generated, with its name string formed by
> concatenating
>         the name of the array and the string "[0]".
> 
>       * For an active variable declared as a structure, a separate
> entry will
>         be generated for each active structure member.  The name of
> each entry
>         is formed by concatenating the name of the structure, the "."
>         character, and the name of the structure member.  If a
> structure
>         member to enumerate is itself a structure or array, these
> enumeration
>         rules are applied recursively.
> 
>       * For an active variable declared as an array of an aggregate
> data type
>         (structures or arrays), a separate entry will be generated
> for each
>         active array element, unless noted immediately below.  The
> name of
>         each entry is formed by concatenating the name of the array,
> the "["
>         character, an integer identifying the element number, and the
> "]"
>         character.  These enumeration rules are applied recursively,
> treating
>         each enumerated array element as a separate active variable.
> 
> > 
> > input_name[0][0]
> > input_name[...][0]
> > input_name[num_vertices-1][0]
> Yes, this is correct. We don't do this with or without this patch. I
> don't know of any tests that exercise this.  Alas.

This is true piq is still broken for AoA 
https://bugs.freedesktop.org/show_bug.cgi?id=92822

Everytime I go to fix it my head starts to spin.

I just find it odd that we would need to include the vertex indices
since from 0 to num_vertices-1 they would all return the same
information.

> 
> > 
> > otherwise
> > 
> > in vec4 input1[];
> > and
> > in vec4 input2[][3];
> > 
> > Would both end up as:
> > input1[0]
> > input2[0]
> > 
> > > 
> > > 
> > > Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
> > > Cc: "12.0" <mesa-stable at lists.freedesktop.org>
> > > ---
> > >  src/mesa/main/shader_query.cpp | 23 ++++++++++-------------
> > >  1 file changed, 10 insertions(+), 13 deletions(-)
> > > 
> > > diff --git a/src/mesa/main/shader_query.cpp
> > > b/src/mesa/main/shader_query.cpp
> > > index eec933c..f4b7243 100644
> > > --- a/src/mesa/main/shader_query.cpp
> > > +++ b/src/mesa/main/shader_query.cpp
> > > @@ -696,20 +696,17 @@ _mesa_program_resource_find_index(struct
> > > gl_shader_program *shProg,
> > >  static bool
> > >  add_index_to_name(struct gl_program_resource *res)
> > >  {
> > > -   bool add_index = !((res->Type == GL_PROGRAM_INPUT &&
> > > -                       res->StageReferences & (1 <<
> > > MESA_SHADER_GEOMETRY |
> > > -                                               1 <<
> > > MESA_SHADER_TESS_CTRL |
> > > -                                               1 <<
> > > MESA_SHADER_TESS_EVAL)) ||
> > > -                      (res->Type == GL_PROGRAM_OUTPUT &&
> > > -                       res->StageReferences & 1 <<
> > > MESA_SHADER_TESS_CTRL));
> > > -
> > > -   /* Transform feedback varyings have array index already
> > > appended
> > > -    * in their names.
> > > -    */
> > > -   if (res->Type == GL_TRANSFORM_FEEDBACK_VARYING)
> > > -      add_index = false;
> > > +   if (res->Type != GL_PROGRAM_INPUT && res->Type !=
> > > GL_PROGRAM_OUTPUT)
> > > +      return res->Type != GL_TRANSFORM_FEEDBACK_VARYING;
> > I'm slighlty confused by this. When does this return true? And for
> > transform feedback wont this always end up us false?
> > 
> > So isn't it just 
> > 
> >    if (res->Type == GL_TRANSFORM_FEEDBACK_VARYING)
> >       return false;
> I thought I tried that but it regressed some dEQP tests.  I'll double
> check.
> 
> > 
> > > 
> > > +
> > > +   const gl_shader_variable *const var = RESOURCE_VAR(res);
> > >  
> > > -   return add_index;
> > > +   assert(var->type->is_array());
> > > +
> > > +   if (var->interface_type != NULL && var->interface_type-
> > > > 
> > > > is_array())
> > > +      return var->type->fields.array->is_array();
> > > +
> > So I'm assuming your doing this since after lowering block[3].foo
> > we
> > end up with foo[3]. However something like block[3].foo[2] will end
> > up
> > as foo[3][2] and blocks can also be arrays of arrays so I'm not
> > sure
> > this will work.
> Correct.  I had forgotten about blocks being arrays-of-arrays.  That
> should be easy enough to fix.
> 
> > 
> > > 
> > > +   return true;
> > >  }
> > >  
> > >  /* Get name length of a program resource. This consists of
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