[Mesa-dev] [PATCH 4/6] i965/fs: implement ir_query_levels

[Kenneth Graunke]

On 10/04/2013 09:17 PM, Chris Forbes wrote:
> Signed-off-by: Chris Forbes <chrisf at ijw.co.nz>
> ---
>  src/mesa/drivers/dri/i965/brw_fs_visitor.cpp | 20 +++++++++++++++++++-
>  1 file changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
> index a8ad659..6141009 100644
> --- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
> @@ -1149,6 +1149,11 @@ fs_visitor::emit_texture_gen5(ir_texture *ir, fs_reg dst, fs_reg coordinate,
>        mlen += reg_width;
>        inst = emit(SHADER_OPCODE_TXS, dst);
>        break;
> +   case ir_query_levels:
> +      emit(MOV(fs_reg(MRF, base_mrf + mlen, BRW_REGISTER_TYPE_UD), fs_reg(0u)));
> +      mlen += reg_width;
> +      inst = emit(SHADER_OPCODE_TXS, dst);
> +      break;
>     case ir_txf:
>        mlen = header_present + 4 * reg_width;
>        emit(MOV(fs_reg(MRF, base_mrf + mlen - reg_width, BRW_REGISTER_TYPE_UD), lod));
> @@ -1259,6 +1264,10 @@ fs_visitor::emit_texture_gen7(ir_texture *ir, fs_reg dst, fs_reg coordinate,
>        emit(MOV(fs_reg(MRF, base_mrf + mlen, BRW_REGISTER_TYPE_UD), lod));
>        mlen += reg_width;
>        break;
> +   case ir_query_levels:
> +      emit(MOV(fs_reg(MRF, base_mrf + mlen, BRW_REGISTER_TYPE_UD), fs_reg(0)));
> +      mlen += reg_width;
> +      break;
>     case ir_txf:
>        /* It appears that the ld instruction used for txf does its
>         * address bounds check before adding in the offset.  To work
> @@ -1314,7 +1323,7 @@ fs_visitor::emit_texture_gen7(ir_texture *ir, fs_reg dst, fs_reg coordinate,
>     }
>  
>     /* Set up the coordinate (except for cases where it was done above) */
> -   if (ir->op != ir_txd && ir->op != ir_txs && ir->op != ir_txf && ir->op != ir_txf_ms) {
> +   if (ir->op != ir_txd && ir->op != ir_txs && ir->op != ir_txf && ir->op != ir_txf_ms && ir->op != ir_query_levels) {

This is getting a bit ridiculous.  It should probably just be:

if (ir->coordinate && ir->op != ir_txd) {
   ...
}

With that change, patch 4 is:
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>

>        for (int i = 0; i < ir->coordinate->type->vector_elements; i++) {
>  	 emit(MOV(fs_reg(MRF, base_mrf + mlen), coordinate));
>  	 coordinate.reg_offset++;
> @@ -1332,6 +1341,7 @@ fs_visitor::emit_texture_gen7(ir_texture *ir, fs_reg dst, fs_reg coordinate,
>     case ir_txf: inst = emit(SHADER_OPCODE_TXF, dst); break;
>     case ir_txf_ms: inst = emit(SHADER_OPCODE_TXF_MS, dst); break;
>     case ir_txs: inst = emit(SHADER_OPCODE_TXS, dst); break;
> +   case ir_query_levels: inst = emit(SHADER_OPCODE_TXS, dst); break;
>     case ir_lod: inst = emit(SHADER_OPCODE_LOD, dst); break;
>     case ir_tg4: inst = emit(SHADER_OPCODE_TG4, dst); break;
>     }
> @@ -1507,6 +1517,7 @@ fs_visitor::visit(ir_texture *ir)
>     case ir_tex:
>     case ir_lod:
>     case ir_tg4:
> +   case ir_query_levels:
>        break;
>     case ir_txb:
>        ir->lod_info.bias->accept(this);
> @@ -1606,6 +1617,13 @@ fs_visitor::gather_channel(ir_texture *ir, int sampler)
>  void
>  fs_visitor::swizzle_result(ir_texture *ir, fs_reg orig_val, int sampler)
>  {
> +   if (ir->op == ir_query_levels) {
> +      /* # levels is in .w */
> +      orig_val.reg_offset += 3;
> +      this->result = orig_val;
> +      return;
> +   }
> +
>     this->result = orig_val;
>  
>     /* txs,lod don't actually sample the texture, so swizzling the result
>