[Mesa-dev] [PATCH 61/78] i965/nir/vec4: Add skeleton implementation of nir_emit_texture()
Alejandro Piñeiro
apinheiro at igalia.com
Wed Jul 1 01:07:30 PDT 2015
On 01/07/15 01:37, Jason Ekstrand wrote:
> If we can avoid duplication in the texturing code, that would be
> really nice. Could we do this as a refactor of the old code and then
> a much smaller NIR function that calls some shared code?
We worked under the assumption that the IR path would be eventually
removed, so having a nir self-contained version would make that removal
easier.
> That's what
> we did for FS and it worked ok.
Yes, I realized that the fs nir path was reusing code, instead of a new
implementation. But as the fs nir code was doing some nir to ir
structure/enum mappings, I assumed that was a first version of the
texture support, and that it would be modified in the future when ir get
ridded. As mentioned, I went directly to a nir self-contained version,
so when ir get ridded, it would not be needed to modify the nir path,
but just remove the ir one.
> I looked at the layout of your code
> and, after you finish reading instruction inputs, very little of it is
> actually NIR-specific.
Yes, current nir texture support is basically using the nir structures
to get all the info, and then just adapt the old code at vec4_visitor,
so it would be possible to reuse the code. In any case, as it is right
now happening with the fs path, probably it would be needed to do some
mappings between nir to ir structures/enums.
I will work now on a version of the support based on refactor the
existing code, in order to be used by the nir and ir paths.
BR
> --Jason
>
> On Fri, Jun 26, 2015 at 1:07 AM, Eduardo Lima Mitev <elima at igalia.com> wrote:
>> From: Alejandro Piñeiro <apinheiro at igalia.com>
>>
>> This sets up the basic structure and placeholders for the implementation of
>> texture operations, which will be added incrementally in subsequent patches.
>>
>> Apart from helping split the texture support into smaller patches, this patch
>> is useful to get a simplified picture of the steps involved in the emission of
>> texture operations.
>>
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89580
>> ---
>> src/mesa/drivers/dri/i965/brw_vec4_nir.cpp | 120 ++++++++++++++++++++++++++++-
>> 1 file changed, 119 insertions(+), 1 deletion(-)
>>
>> diff --git a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
>> index 08a70b0..c3638a0 100644
>> --- a/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
>> +++ b/src/mesa/drivers/dri/i965/brw_vec4_nir.cpp
>> @@ -1412,7 +1412,125 @@ vec4_visitor::nir_swizzle_result(nir_tex_instr *instr, dst_reg dest,
>> void
>> vec4_visitor::nir_emit_texture(nir_tex_instr *instr)
>> {
>> - /* @TODO: Not yet implemented */
>> + unsigned sampler = instr->sampler_index;
>> + src_reg sampler_reg = src_reg(sampler);
>> +
>> + const glsl_type *dest_type;
>> +
>> + /* Load the texture operation sources */
>> + for (unsigned i = 0; i < instr->num_srcs; i++) {
>> + src_reg src = get_nir_src(instr->src[i].src);
>> +
>> + switch (instr->src[i].src_type) {
>> + case nir_tex_src_comparitor:
>> + /* @TODO: not yet implemented */
>> + break;
>> +
>> + case nir_tex_src_coord:
>> + /* @TODO: not yet implemented */
>> + break;
>> +
>> + case nir_tex_src_ddx:
>> + /* @TODO: not yet implemented */
>> + break;
>> +
>> + case nir_tex_src_ddy:
>> + /* @TODO: not yet implemented */
>> + break;
>> +
>> + case nir_tex_src_lod:
>> + /* @TODO: not yet implemented */
>> + break;
>> +
>> + case nir_tex_src_ms_index:
>> + /* @TODO: not yet implemented */
>> + break;
>> +
>> + case nir_tex_src_offset:
>> + /* @TODO: not yet implemented */
>> + break;
>> +
>> + case nir_tex_src_sampler_offset:
>> + /* @TODO: not yet implemented */
>> + break;
>> +
>> + case nir_tex_src_projector:
>> + unreachable("Should be lowered by do_lower_texture_projection");
>> +
>> + case nir_tex_src_bias:
>> + unreachable("LOD bias is not valid for vertex shaders.\n");
>> +
>> + default:
>> + unreachable("unknown texture source");
>> + }
>> + }
>> +
>> + /* Get the texture operation opcode */
>> + enum opcode opcode = shader_opcode_for_nir_opcode(instr->op);
>> +
>> + /* Build the instruction */
>> + enum glsl_base_type dest_base_type =
>> + brw_glsl_base_type_for_nir_type(instr->dest_type);
>> +
>> + dest_type =
>> + glsl_type::get_instance(dest_base_type, nir_tex_instr_dest_size(instr), 1);
>> +
>> + vec4_instruction *inst = new(mem_ctx)
>> + vec4_instruction(opcode, dst_reg(this, dest_type));
>> +
>> + for (unsigned i = 0; i < 3; i++) {
>> + if (instr->const_offset[i] != 0) {
>> + inst->offset = brw_texture_offset(instr->const_offset, 3);
>> + break;
>> + }
>> + }
>> +
>> + /* The message header is necessary for:
>> + * - Texel offsets
>> + * - Gather channel selection
>> + * - Sampler indices too large to fit in a 4-bit value.
>> + */
>> + inst->header_size =
>> + (inst->offset != 0 ||
>> + instr->op == nir_texop_tg4 ||
>> + is_high_sampler(sampler_reg)) ? 1 : 0;
>> + inst->base_mrf = 2;
>> + inst->mlen = inst->header_size + 1;
>> + inst->dst.writemask = WRITEMASK_XYZW;
>> +
>> + inst->src[1] = sampler_reg;
>> +
>> + /* Calculate the MRF for the first parameter */
>> + int param_base = inst->base_mrf + inst->header_size;
>> +
>> + if (instr->op == nir_texop_txs || instr->op == nir_texop_query_levels) {
>> + /* @TODO: not yet implemented */
>> + } else {
>> + /* @TODO: Load the coordinate */
>> +
>> + /* @TODO: Load the shadow comparitor */
>> +
>> + /* Load the LOD info */
>> + if (instr->op == nir_texop_tex || instr->op == nir_texop_txl) {
>> + /* @TODO: not yet implemented */
>> + } else if (instr->op == nir_texop_txf) {
>> + /* @TODO: not yet implemented */
>> + } else if (instr->op == nir_texop_txf_ms) {
>> + /* @TODO: not yet implemented */
>> + } else if (instr->op == nir_texop_txd) {
>> + /* @TODO: not yet implemented */
>> + } else if (instr->op == nir_texop_tg4) {
>> + /* @TODO: not yet implemented */
>> + }
>> + }
>> +
>> + /* Emit the instruction */
>> + emit(inst);
>> +
>> + /* Move the result to the destination registry, applying swizzle */
>> + dst_reg dest = get_nir_dest(instr->dest, brw_type_for_base_type(dest_type));
>> +
>> + nir_swizzle_result(instr, dest, src_reg(inst->dst), sampler, dest_type);
>> }
>>
>> }
>> --
>> 2.1.4
>>
>> _______________________________________________
>> mesa-dev mailing list
>> mesa-dev at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
--
Alejandro Piñeiro (apinheiro at igalia.com)
More information about the mesa-dev
mailing list