[Mesa-dev] [PATCH v3 29/48] intel/cs: Rework the way thread local ID is handled
Iago Toral
itoral at igalia.com
Fri Oct 27 09:11:14 UTC 2017
On Wed, 2017-10-25 at 16:26 -0700, Jason Ekstrand wrote:
> Previously, brw_nir_lower_intrinsics added the param and then emitted
> a
> load_uniform intrinsic to load it directly. This commit switches
> things
> over to use a specific NIR intrinsic for the thread id. The one
> thing I
> don't like about this approach is that we have to copy
> thread_local_id
> over to the new visitor in import_uniforms.
It is not clear to me why you are doing this... why do you like this
better?
> ---
> src/compiler/nir/nir_intrinsics.h | 3 ++
> src/intel/compiler/brw_fs.cpp | 4 +-
> src/intel/compiler/brw_fs.h | 1 +
> src/intel/compiler/brw_fs_nir.cpp | 14 +++++++
> src/intel/compiler/brw_nir.h | 3 +-
> src/intel/compiler/brw_nir_lower_cs_intrinsics.c | 53 +++++---------
> ----------
> 6 files changed, 32 insertions(+), 46 deletions(-)
>
> diff --git a/src/compiler/nir/nir_intrinsics.h
> b/src/compiler/nir/nir_intrinsics.h
> index cefd18b..47022dd 100644
> --- a/src/compiler/nir/nir_intrinsics.h
> +++ b/src/compiler/nir/nir_intrinsics.h
> @@ -364,6 +364,9 @@ SYSTEM_VALUE(blend_const_color_a_float, 1, 0, xx,
> xx, xx)
> SYSTEM_VALUE(blend_const_color_rgba8888_unorm, 1, 0, xx, xx, xx)
> SYSTEM_VALUE(blend_const_color_aaaa8888_unorm, 1, 0, xx, xx, xx)
>
> +/* Intel specific system values */
> +SYSTEM_VALUE(intel_thread_local_id, 1, 0, xx, xx, xx)
> +
> /**
> * Barycentric coordinate intrinsics.
> *
> diff --git a/src/intel/compiler/brw_fs.cpp
> b/src/intel/compiler/brw_fs.cpp
> index 2acd838..c0d4c05 100644
> --- a/src/intel/compiler/brw_fs.cpp
> +++ b/src/intel/compiler/brw_fs.cpp
> @@ -996,6 +996,7 @@ fs_visitor::import_uniforms(fs_visitor *v)
> this->push_constant_loc = v->push_constant_loc;
> this->pull_constant_loc = v->pull_constant_loc;
> this->uniforms = v->uniforms;
> + this->thread_local_id = v->thread_local_id;
> }
>
> void
> @@ -6781,8 +6782,7 @@ brw_compile_cs(const struct brw_compiler
> *compiler, void *log_data,
> {
> nir_shader *shader = nir_shader_clone(mem_ctx, src_shader);
> shader = brw_nir_apply_sampler_key(shader, compiler, &key->tex,
> true);
> -
> - brw_nir_lower_cs_intrinsics(shader, prog_data);
> + brw_nir_lower_cs_intrinsics(shader);
> shader = brw_postprocess_nir(shader, compiler, true);
>
> prog_data->local_size[0] = shader->info.cs.local_size[0];
> diff --git a/src/intel/compiler/brw_fs.h
> b/src/intel/compiler/brw_fs.h
> index da32593..f51a4d8 100644
> --- a/src/intel/compiler/brw_fs.h
> +++ b/src/intel/compiler/brw_fs.h
> @@ -315,6 +315,7 @@ public:
> */
> int *push_constant_loc;
>
> + fs_reg thread_local_id;
> fs_reg frag_depth;
> fs_reg frag_stencil;
> fs_reg sample_mask;
> diff --git a/src/intel/compiler/brw_fs_nir.cpp
> b/src/intel/compiler/brw_fs_nir.cpp
> index 05efee3..fdc6fc6 100644
> --- a/src/intel/compiler/brw_fs_nir.cpp
> +++ b/src/intel/compiler/brw_fs_nir.cpp
> @@ -88,6 +88,16 @@ fs_visitor::nir_setup_uniforms()
> }
>
> uniforms = nir->num_uniforms / 4;
> +
> + if (stage == MESA_SHADER_COMPUTE) {
> + /* Add a uniform for the thread local id. It must be the last
> uniform
> + * on the list.
> + */
> + assert(uniforms == prog_data->nr_params);
> + uint32_t *param = brw_stage_prog_data_add_params(prog_data,
> 1);
> + *param = BRW_PARAM_BUILTIN_THREAD_LOCAL_ID;
> + thread_local_id = fs_reg(UNIFORM, uniforms++,
> BRW_REGISTER_TYPE_UD);
> + }
> }
>
> static bool
> @@ -3409,6 +3419,10 @@ fs_visitor::nir_emit_cs_intrinsic(const
> fs_builder &bld,
> cs_prog_data->uses_barrier = true;
> break;
>
> + case nir_intrinsic_load_intel_thread_local_id:
> + bld.MOV(retype(dest, BRW_REGISTER_TYPE_UD), thread_local_id);
> + break;
> +
> case nir_intrinsic_load_local_invocation_id:
> case nir_intrinsic_load_work_group_id: {
> gl_system_value sv = nir_system_value_from_intrinsic(instr-
> >intrinsic);
> diff --git a/src/intel/compiler/brw_nir.h
> b/src/intel/compiler/brw_nir.h
> index 1493b74..3e40712 100644
> --- a/src/intel/compiler/brw_nir.h
> +++ b/src/intel/compiler/brw_nir.h
> @@ -95,8 +95,7 @@ void brw_nir_analyze_boolean_resolves(nir_shader
> *nir);
> nir_shader *brw_preprocess_nir(const struct brw_compiler *compiler,
> nir_shader *nir);
>
> -bool brw_nir_lower_cs_intrinsics(nir_shader *nir,
> - struct brw_cs_prog_data
> *prog_data);
> +bool brw_nir_lower_cs_intrinsics(nir_shader *nir);
> void brw_nir_lower_vs_inputs(nir_shader *nir,
> bool use_legacy_snorm_formula,
> const uint8_t *vs_attrib_wa_flags);
> diff --git a/src/intel/compiler/brw_nir_lower_cs_intrinsics.c
> b/src/intel/compiler/brw_nir_lower_cs_intrinsics.c
> index d277276..07d2dcc 100644
> --- a/src/intel/compiler/brw_nir_lower_cs_intrinsics.c
> +++ b/src/intel/compiler/brw_nir_lower_cs_intrinsics.c
> @@ -26,47 +26,12 @@
>
> struct lower_intrinsics_state {
> nir_shader *nir;
> - struct brw_cs_prog_data *prog_data;
> nir_function_impl *impl;
> bool progress;
> nir_builder builder;
> - int thread_local_id_index;
> + unsigned local_workgroup_size;
> };
>
> -static nir_ssa_def *
> -read_thread_local_id(struct lower_intrinsics_state *state)
> -{
> - struct brw_cs_prog_data *prog_data = state->prog_data;
> - nir_builder *b = &state->builder;
> - nir_shader *nir = state->nir;
> - const unsigned *sizes = nir->info.cs.local_size;
> - const unsigned group_size = sizes[0] * sizes[1] * sizes[2];
> -
> - /* Some programs have local_size dimensions so small that the
> thread local
> - * ID will always be 0.
> - */
> - if (group_size <= 8)
> - return nir_imm_int(b, 0);
> -
> - if (state->thread_local_id_index == -1) {
> - state->thread_local_id_index = prog_data->base.nr_params;
> - uint32_t *param = brw_stage_prog_data_add_params(&prog_data-
> >base, 1);
> - *param = BRW_PARAM_BUILTIN_THREAD_LOCAL_ID;
> - nir->num_uniforms += 4;
> - }
> - unsigned id_index = state->thread_local_id_index;
> -
> - nir_intrinsic_instr *load =
> - nir_intrinsic_instr_create(nir, nir_intrinsic_load_uniform);
> - load->num_components = 1;
> - load->src[0] = nir_src_for_ssa(nir_imm_int(b, 0));
> - nir_ssa_dest_init(&load->instr, &load->dest, 1, 32, NULL);
> - nir_intrinsic_set_base(load, id_index * sizeof(uint32_t));
> - nir_intrinsic_set_range(load, sizeof(uint32_t));
> - nir_builder_instr_insert(b, &load->instr);
> - return &load->dest.ssa;
> -}
> -
> static bool
> lower_cs_intrinsics_convert_block(struct lower_intrinsics_state
> *state,
> nir_block *block)
> @@ -91,7 +56,12 @@ lower_cs_intrinsics_convert_block(struct
> lower_intrinsics_state *state,
> * gl_LocalInvocationIndex =
> * cs_thread_local_id + subgroup_invocation;
> */
> - nir_ssa_def *thread_local_id = read_thread_local_id(state);
> + nir_ssa_def *thread_local_id;
> + if (state->local_workgroup_size <= 8)
> + thread_local_id = nir_imm_int(b, 0);
> + else
> + thread_local_id = nir_load_intel_thread_local_id(b);
> +
> nir_ssa_def *channel = nir_load_subgroup_invocation(b);
> sysval = nir_iadd(b, channel, thread_local_id);
> break;
> @@ -157,8 +127,7 @@ lower_cs_intrinsics_convert_impl(struct
> lower_intrinsics_state *state)
> }
>
> bool
> -brw_nir_lower_cs_intrinsics(nir_shader *nir,
> - struct brw_cs_prog_data *prog_data)
> +brw_nir_lower_cs_intrinsics(nir_shader *nir)
> {
> assert(nir->info.stage == MESA_SHADER_COMPUTE);
>
> @@ -166,9 +135,9 @@ brw_nir_lower_cs_intrinsics(nir_shader *nir,
> struct lower_intrinsics_state state;
> memset(&state, 0, sizeof(state));
> state.nir = nir;
> - state.prog_data = prog_data;
> -
> - state.thread_local_id_index = -1;
> + state.local_workgroup_size = nir->info.cs.local_size[0] *
> + nir->info.cs.local_size[1] *
> + nir->info.cs.local_size[2];
>
> do {
> state.progress = false;
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