[Mesa-dev] [PATCH 10/12] i965/fs: Reimplement emit_texture() in terms of logical send messages.

[Jason Ekstrand]

On Wed, Jul 22, 2015 at 12:41 AM, Francisco Jerez <currojerez at riseup.net> wrote:
> Jason Ekstrand <jason at jlekstrand.net> writes:
>
>> On Sat, Jul 18, 2015 at 7:34 AM, Francisco Jerez <currojerez at riseup.net> wrote:
>>> ---
>>>  src/mesa/drivers/dri/i965/brw_fs_visitor.cpp | 66 +++++++++++++++++++++-------
>>>  1 file changed, 49 insertions(+), 17 deletions(-)
>>>
>>> diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
>>> index 89fcc49..4011639 100644
>>> --- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
>>> +++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
>>> @@ -861,6 +861,14 @@ fs_visitor::emit_texture(ir_texture_opcode op,
>>>        }
>>>     }
>>>
>>> +   if (op == ir_query_levels) {
>>> +      /* textureQueryLevels() is implemented in terms of TXS so we need to
>>> +       * pass a valid LOD argument.
>>> +       */
>>> +      assert(lod.file == BAD_FILE);
>>> +      lod = fs_reg(0u);
>>
>> Why can't this go as part of the switch below?  It seems kind of odd
>> to split the logic up like this.
>>
> What I had in mind originally was to factor out the switch statement
> below into a separate function -- Later on I noticed that you wanted to
> rework emit_texture() and friends to stop using ir_texture_opcode as
> representation for the texturing operation, so you would likely want to
> get rid of the whole switch-case statement below or replace it with
> something else, so I didn't bother.  What are your current plans for
> emit_texture()?

At this point, we may just roll it into nir_emit_texture or we may
leave it alone.  In any case, we will want to get rid of the
ir_texture_opcode eventually.  Feel free to leave this patch as is.  I
can merge things or whatever as needed whenever we do that refactor.

>>> +   }
>>> +
>>>     if (coordinate.file != BAD_FILE) {
>>>        /* FINISHME: Texture coordinate rescaling doesn't work with non-constant
>>>         * samplers.  This should only be a problem with GL_CLAMP on Gen7.
>>> @@ -873,26 +881,50 @@ fs_visitor::emit_texture(ir_texture_opcode op,
>>>      * samples, so don't worry about them.
>>>      */
>>>     fs_reg dst = vgrf(glsl_type::get_instance(dest_type->base_type, 4, 1));
>>> +   const fs_reg srcs[] = {
>>> +      coordinate, shadow_c, lod, lod2,
>>> +      sample_index, mcs, sampler_reg, offset_value,
>>> +      fs_reg(coord_components), fs_reg(grad_components)
>>> +   };
>>> +   enum opcode opcode;
>>>
>>> -   if (devinfo->gen >= 7) {
>>> -      inst = emit_texture_gen7(op, dst, coordinate, coord_components,
>>> -                               shadow_c, lod, lod2, grad_components,
>>> -                               sample_index, mcs, sampler_reg,
>>> -                               offset_value);
>>> -   } else if (devinfo->gen >= 5) {
>>> -      inst = emit_texture_gen5(op, dst, coordinate, coord_components,
>>> -                               shadow_c, lod, lod2, grad_components,
>>> -                               sample_index, sampler,
>>> -                               offset_value.file != BAD_FILE);
>>> -   } else if (dispatch_width == 16) {
>>> -      inst = emit_texture_gen4_simd16(op, dst, coordinate, coord_components,
>>> -                                      shadow_c, lod, sampler);
>>> -   } else {
>>> -      inst = emit_texture_gen4(op, dst, coordinate, coord_components,
>>> -                               shadow_c, lod, lod2, grad_components,
>>> -                               sampler);
>>> +   switch (op) {
>>> +   case ir_tex:
>>> +      opcode = SHADER_OPCODE_TEX_LOGICAL;
>>> +      break;
>>> +   case ir_txb:
>>> +      opcode = FS_OPCODE_TXB_LOGICAL;
>>> +      break;
>>> +   case ir_txl:
>>> +      opcode = SHADER_OPCODE_TXL_LOGICAL;
>>> +      break;
>>> +   case ir_txd:
>>> +      opcode = SHADER_OPCODE_TXD_LOGICAL;
>>> +      break;
>>> +   case ir_txf:
>>> +      opcode = SHADER_OPCODE_TXF_LOGICAL;
>>> +      break;
>>> +   case ir_txf_ms:
>>> +      opcode = SHADER_OPCODE_TXF_CMS_LOGICAL;
>>> +      break;
>>> +   case ir_txs:
>>> +   case ir_query_levels:
>>> +      opcode = SHADER_OPCODE_TXS_LOGICAL;
>>> +      break;
>>> +   case ir_lod:
>>> +      opcode = SHADER_OPCODE_LOD_LOGICAL;
>>> +      break;
>>> +   case ir_tg4:
>>> +      opcode = (offset_value.file != BAD_FILE && offset_value.file != IMM ?
>>> +                SHADER_OPCODE_TG4_OFFSET_LOGICAL : SHADER_OPCODE_TG4_LOGICAL);
>>> +      break;
>>> +   default:
>>> +      unreachable("not reached");
>>
>> Please choose something more descriptive than "not reached".  How
>> about "invalid texture opcode"
>
> Sure, I'll fix that, thanks.
>
>>
>>>     }
>>>
>>> +   inst = bld.emit(opcode, dst, srcs, ARRAY_SIZE(srcs));
>>> +   inst->regs_written = 4 * dispatch_width / 8;
>>> +
>>>     if (shadow_c.file != BAD_FILE)
>>>        inst->shadow_compare = true;
>>>
>>> --
>>> 2.4.3
>>>