[Mesa-dev] [PATCH 4/4] mesa: fix validate for secondary interpolator

[Ian Romanick]

On 11/20/2017 04:07 PM, Miklós Máté wrote:
> This patch fixes multiple problems:
> - the interpolator check was duplicated
> - both had arg instead of argRep
> - I split it into color and alpha for better readability and error msg
> - the DOT4 check only applies to color instruction according to the spec

For the sake of reviewers and the next person to look at this code, a
spec quotation or two in the code would be really helpful.

> - made the DOT4 check fatal, and improved the error msg
> 
> Piglit: spec/ati_fragment_shader/error08-secondary
> 
> Signed-off-by: Miklós Máté <mtmkls at gmail.com>
> ---
>  src/mesa/main/atifragshader.c | 23 ++++++++++++-----------
>  1 file changed, 12 insertions(+), 11 deletions(-)
> 
> diff --git a/src/mesa/main/atifragshader.c b/src/mesa/main/atifragshader.c
> index 313ba0c66d..1bca8267b8 100644
> --- a/src/mesa/main/atifragshader.c
> +++ b/src/mesa/main/atifragshader.c
> @@ -171,15 +171,15 @@ static int check_arith_arg(struct ati_fragment_shader *curProg,
>        _mesa_error(ctx, GL_INVALID_ENUM, "C/AFragmentOpATI(arg)");
>        return 0;
>     }
> -   if ((arg == GL_SECONDARY_INTERPOLATOR_ATI) && (((optype == 0) && (argRep == GL_ALPHA)) ||
> -      ((optype == 1) && ((arg == GL_ALPHA) || (argRep == GL_NONE))))) {
> -      _mesa_error(ctx, GL_INVALID_OPERATION, "C/AFragmentOpATI(sec_interp)");
> -      return 0;
> -   }
> -   if ((arg == GL_SECONDARY_INTERPOLATOR_ATI) && (((optype == 0) && (argRep == GL_ALPHA)) ||
> -      ((optype == 1) && ((arg == GL_ALPHA) || (argRep == GL_NONE))))) {
> -      _mesa_error(ctx, GL_INVALID_OPERATION, "C/AFragmentOpATI(sec_interp)");
> -      return 0;

Adding this comment here makes it clear that the code is correct.

   /* The ATI_fragment_shader spec says:
    *
    *        The error INVALID_OPERATION is generated by
    *        ColorFragmentOp[1..3]ATI if <argN> is SECONDARY_INTERPOLATOR_ATI
    *        and <argNRep> is ALPHA, or by AlphaFragmentOp[1..3]ATI if <argN>
    *        is SECONDARY_INTERPOLATOR_ATI and <argNRep> is ALPHA or NONE, ...
    */

> +   if (arg == GL_SECONDARY_INTERPOLATOR_ATI) {
> +      if ((optype == ATI_FRAGMENT_SHADER_COLOR_OP) && (argRep == GL_ALPHA)) {

Like before, drop the unnecessary ().

> +         _mesa_error(ctx, GL_INVALID_OPERATION, "CFragmentOpATI(sec_interp)");
> +         return 0;
> +      } else if ((optype == ATI_FRAGMENT_SHADER_ALPHA_OP) &&
> +            ((argRep == GL_ALPHA) || (argRep == GL_NONE))) {

Remove extra () and line up with the opening (.

> +         _mesa_error(ctx, GL_INVALID_OPERATION, "AFragmentOpATI(sec_interp)");
> +         return 0;
> +      }
>     }
>     if ((curProg->cur_pass == 1) &&
>        ((arg == GL_PRIMARY_COLOR_ARB) || (arg == GL_SECONDARY_INTERPOLATOR_ATI))) {
> @@ -642,10 +642,11 @@ _mesa_FragmentOpXATI(GLint optype, GLuint arg_count, GLenum op, GLuint dst,
>  	 return;
>        }
>     }

Same here regarding the comment.

   /* The ATI_fragment_shader spec says:
    *
    *        The error INVALID_OPERATION is generated by... ColorFragmentOp2ATI
    *        if <op> is DOT4_ATI and <argN> is SECONDARY_INTERPOLATOR_ATI and
    *        <argNRep> is ALPHA or NONE.
    */

> -   if ((op == GL_DOT4_ATI) &&
> +   if ((optype == ATI_FRAGMENT_SHADER_COLOR_OP) && (op == GL_DOT4_ATI) &&
>        (((arg1 == GL_SECONDARY_INTERPOLATOR_ATI) && ((arg1Rep == GL_ALPHA) || (arg1Rep == GL_NONE))) ||
>        (((arg2 == GL_SECONDARY_INTERPOLATOR_ATI) && ((arg2Rep == GL_ALPHA) || (arg2Rep == GL_NONE)))))) {
> -      _mesa_error(ctx, GL_INVALID_OPERATION, "C/AFragmentOpATI(sec_interp)");
> +      _mesa_error(ctx, GL_INVALID_OPERATION, "C/AFragmentOpATI(sec_interpDOT4)");
> +      return;
>     }
>  
>     if (!check_arith_arg(curProg, optype, arg1, arg1Rep)) {
>