[Mesa-dev] [PATCH 03/11] st/mesa: implement GL_ATI_fragment_shader

[Ilia Mirkin]

On Tue, Dec 15, 2015 at 6:05 PM, Miklós Máté <mtmkls at gmail.com> wrote:
> +   } else if (desc->special == 3) {
> +      src[0] = args[0];
> +      src[1] = args[1];
> +      src[2] = ureg_swizzle(args[2],
> +            TGSI_SWIZZLE_Z, TGSI_SWIZZLE_Z, TGSI_SWIZZLE_Z, TGSI_SWIZZLE_Z);
> +      emit_insn(t, TGSI_OPCODE_DP2A, dst, 1, src, 3);
> +   }

Not strictly your fault, but in practice, no backends actually
implement DP2A. Not sure why -- i915, nv30, and r300 even have
explicit ops for this. You can use DP2 + ADD. Or go around all the
backends an implement it.

  -ilia