[v2 1/3] wined3d: Implement return instruction.

[Józef Kucia]

On Tue, Nov 22, 2016 at 2:00 AM, Matteo Bruni <matteo.mystral at gmail.com> wrote:
>> Would it make sense to always generate a shader epilogue for shader
>> model <= 3, and handle the RET instruction in a special way for shader
>> model >= 4?
>
> Notice that the RET instruction is also used for returning from
> subroutines. Now, I don't know that anyone has ever used subroutines
> in d3d shaders (especially for SM <= 3) but probably the correct thing
> to do is to only generate an additional shader epilogue for RETs
> called from the main function. That means keeping track of whether we
> are in the main shader or in a subroutine (maybe by extending /
> renaming struct wined3d_shader_loop_state) and only generating the
> epilogue for RETs called from the main shader.

Yeah, but generating a shader epilogue always in
shader_glsl_generate_pshader() and shader_glsl_generate_vshader(),
i.e. the current behavior should work fine for shader model <= 3. We
will probably need to revisit this code when implementing tessellation
shaders or SM4 subroutines.