From 6af5e0bec97c2369c29cfbbaf56046eecd218f7a Mon Sep 17 00:00:00 2001 From: Timothy Arceri Date: Fri, 6 Oct 2017 09:19:35 +1100 Subject: [PATCH] nir: add variant of lower_io_to_scalar to be called earlier This is intended to be called before nir_lower_io() so that we can do some linking optimisations with the results. It can also be used with drivers that don't use nir_lower_io() at all such as RADV. v2: pass mode mask rather than first and last stage integer. Reviewed-by: Eric Anholt --- src/compiler/nir/nir.h | 1 + src/compiler/nir/nir_lower_io_to_scalar.c | 254 ++++++++++++++++++++++ 2 files changed, 255 insertions(+) diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index 5af150310f2..bd6035e1f90 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -2454,6 +2454,7 @@ bool nir_lower_load_const_to_scalar(nir_shader *shader); bool nir_lower_read_invocation_to_scalar(nir_shader *shader); bool nir_lower_phis_to_scalar(nir_shader *shader); void nir_lower_io_to_scalar(nir_shader *shader, nir_variable_mode mask); +void nir_lower_io_to_scalar_early(nir_shader *shader, nir_variable_mode mask); bool nir_lower_samplers(nir_shader *shader, const struct gl_shader_program *shader_program); diff --git a/src/compiler/nir/nir_lower_io_to_scalar.c b/src/compiler/nir/nir_lower_io_to_scalar.c index fffd1d3d2bb..7774c2d2458 100644 --- a/src/compiler/nir/nir_lower_io_to_scalar.c +++ b/src/compiler/nir/nir_lower_io_to_scalar.c @@ -127,3 +127,257 @@ nir_lower_io_to_scalar(nir_shader *shader, nir_variable_mode mask) } } } + +static nir_variable ** +get_channel_variables(struct hash_table *ht, nir_variable *var) +{ + nir_variable **chan_vars; + struct hash_entry *entry = _mesa_hash_table_search(ht, var); + if (!entry) { + chan_vars = (nir_variable **) calloc(4, sizeof(nir_variable *)); + _mesa_hash_table_insert(ht, var, chan_vars); + } else { + chan_vars = (nir_variable **) entry->data; + } + + return chan_vars; +} + +/* + * This function differs from nir_deref_clone() in that it gets its type from + * the parent deref rather than our source deref. This is useful when splitting + * vectors because we want to use the scalar type of the new parent rather than + * then the old vector type. + */ +static nir_deref_array * +clone_deref_array(const nir_deref_array *darr, nir_deref *parent) +{ + nir_deref_array *ndarr = nir_deref_array_create(parent); + + ndarr->deref.type = glsl_get_array_element(parent->type); + if (darr->deref.child) + ndarr->deref.child = + &clone_deref_array(nir_deref_as_array(darr->deref.child), + &ndarr->deref)->deref; + + ndarr->deref_array_type = darr->deref_array_type; + ndarr->base_offset = darr->base_offset; + if (ndarr->deref_array_type == nir_deref_array_type_indirect) + nir_src_copy(&ndarr->indirect, &darr->indirect, parent); + + return ndarr; +} + +static void +lower_load_to_scalar_early(nir_builder *b, nir_intrinsic_instr *intr, + nir_variable *var, struct hash_table *split_inputs, + struct hash_table *split_outputs) +{ + b->cursor = nir_before_instr(&intr->instr); + + assert(intr->dest.is_ssa); + + nir_ssa_def *loads[4]; + + nir_variable **chan_vars; + if (var->data.mode == nir_var_shader_in) { + chan_vars = get_channel_variables(split_inputs, var); + } else { + chan_vars = get_channel_variables(split_outputs, var); + } + + for (unsigned i = 0; i < intr->num_components; i++) { + nir_variable *chan_var = chan_vars[var->data.location_frac + i]; + if (!chan_vars[var->data.location_frac + i]) { + chan_var = nir_variable_clone(var, b->shader); + chan_var->data.location_frac = var->data.location_frac + i; + chan_var->type = glsl_channel_type(chan_var->type); + + chan_vars[var->data.location_frac + i] = chan_var; + + nir_shader_add_variable(b->shader, chan_var); + } + + nir_intrinsic_instr *chan_intr = + nir_intrinsic_instr_create(b->shader, intr->intrinsic); + nir_ssa_dest_init(&chan_intr->instr, &chan_intr->dest, + 1, intr->dest.ssa.bit_size, NULL); + chan_intr->num_components = 1; + chan_intr->variables[0] = nir_deref_var_create(chan_intr, chan_var); + + if (intr->variables[0]->deref.child) { + chan_intr->variables[0]->deref.child = + &clone_deref_array(nir_deref_as_array(intr->variables[0]->deref.child), + &chan_intr->variables[0]->deref)->deref; + } + + if (intr->intrinsic == nir_intrinsic_interp_var_at_offset || + intr->intrinsic == nir_intrinsic_interp_var_at_sample) + nir_src_copy(chan_intr->src, intr->src, &chan_intr->instr); + + nir_builder_instr_insert(b, &chan_intr->instr); + + loads[i] = &chan_intr->dest.ssa; + } + + nir_ssa_def_rewrite_uses(&intr->dest.ssa, + nir_src_for_ssa(nir_vec(b, loads, + intr->num_components))); + + /* Remove the old load intrinsic */ + nir_instr_remove(&intr->instr); +} + +static void +lower_store_output_to_scalar_early(nir_builder *b, nir_intrinsic_instr *intr, + nir_variable *var, + struct hash_table *split_outputs) +{ + b->cursor = nir_before_instr(&intr->instr); + + nir_ssa_def *value = nir_ssa_for_src(b, intr->src[0], intr->num_components); + + nir_variable **chan_vars = get_channel_variables(split_outputs, var); + for (unsigned i = 0; i < intr->num_components; i++) { + if (!(nir_intrinsic_write_mask(intr) & (1 << i))) + continue; + + nir_variable *chan_var = chan_vars[var->data.location_frac + i]; + if (!chan_vars[var->data.location_frac + i]) { + chan_var = nir_variable_clone(var, b->shader); + chan_var->data.location_frac = var->data.location_frac + i; + chan_var->type = glsl_channel_type(chan_var->type); + + chan_vars[var->data.location_frac + i] = chan_var; + + nir_shader_add_variable(b->shader, chan_var); + } + + nir_intrinsic_instr *chan_intr = + nir_intrinsic_instr_create(b->shader, intr->intrinsic); + chan_intr->num_components = 1; + + nir_intrinsic_set_write_mask(chan_intr, 0x1); + + chan_intr->variables[0] = nir_deref_var_create(chan_intr, chan_var); + chan_intr->src[0] = nir_src_for_ssa(nir_channel(b, value, i)); + + if (intr->variables[0]->deref.child) { + chan_intr->variables[0]->deref.child = + &clone_deref_array(nir_deref_as_array(intr->variables[0]->deref.child), + &chan_intr->variables[0]->deref)->deref; + } + + nir_builder_instr_insert(b, &chan_intr->instr); + } + + /* Remove the old store intrinsic */ + nir_instr_remove(&intr->instr); +} + +/* + * This function is intended to be called earlier than nir_lower_io_to_scalar() + * i.e. before nir_lower_io() is called. + */ +void +nir_lower_io_to_scalar_early(nir_shader *shader, nir_variable_mode mask) +{ + struct hash_table *split_inputs = + _mesa_hash_table_create(NULL, _mesa_hash_pointer, + _mesa_key_pointer_equal); + struct hash_table *split_outputs = + _mesa_hash_table_create(NULL, _mesa_hash_pointer, + _mesa_key_pointer_equal); + + nir_foreach_function(function, shader) { + if (function->impl) { + nir_builder b; + nir_builder_init(&b, function->impl); + + nir_foreach_block(block, function->impl) { + nir_foreach_instr_safe(instr, block) { + if (instr->type != nir_instr_type_intrinsic) + continue; + + nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); + + if (intr->num_components == 1) + continue; + + if (intr->intrinsic != nir_intrinsic_load_var && + intr->intrinsic != nir_intrinsic_store_var && + intr->intrinsic != nir_intrinsic_interp_var_at_centroid && + intr->intrinsic != nir_intrinsic_interp_var_at_sample && + intr->intrinsic != nir_intrinsic_interp_var_at_offset) + continue; + + nir_variable *var = intr->variables[0]->var; + nir_variable_mode mode = var->data.mode; + + /* TODO: add patch support */ + if (var->data.patch) + continue; + + /* TODO: add doubles support */ + if (glsl_type_is_64bit(glsl_without_array(var->type))) + continue; + + if (var->data.location < VARYING_SLOT_VAR0 && + var->data.location >= 0) + continue; + + /* Don't bother splitting if we can't opt away any unused + * components. + */ + if (var->data.always_active_io) + continue; + + /* Skip types we cannot split */ + if (glsl_type_is_matrix(glsl_without_array(var->type)) || + glsl_type_is_struct(glsl_without_array(var->type))) + continue; + + switch (intr->intrinsic) { + case nir_intrinsic_interp_var_at_centroid: + case nir_intrinsic_interp_var_at_sample: + case nir_intrinsic_interp_var_at_offset: + case nir_intrinsic_load_var: + if ((mask & nir_var_shader_in && mode == nir_var_shader_in) || + (mask & nir_var_shader_out && mode == nir_var_shader_out)) + lower_load_to_scalar_early(&b, intr, var, split_inputs, + split_outputs); + break; + case nir_intrinsic_store_var: + if (mask & nir_var_shader_out && + mode == nir_var_shader_out) + lower_store_output_to_scalar_early(&b, intr, var, + split_outputs); + break; + default: + break; + } + } + } + } + } + + /* Remove old input from the shaders inputs list */ + struct hash_entry *entry; + hash_table_foreach(split_inputs, entry) { + nir_variable *var = (nir_variable *) entry->key; + exec_node_remove(&var->node); + + free(entry->data); + } + + /* Remove old output from the shaders outputs list */ + hash_table_foreach(split_outputs, entry) { + nir_variable *var = (nir_variable *) entry->key; + exec_node_remove(&var->node); + + free(entry->data); + } + + _mesa_hash_table_destroy(split_inputs, NULL); + _mesa_hash_table_destroy(split_outputs, NULL); +} -- 2.30.2