/*
* Copyright © 2016 Broadcom
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include "nir.h"
#include "nir_builder.h"
/** @file nir_lower_io_to_scalar.c
*
* Replaces nir_load_input/nir_store_output operations with num_components !=
* 1 with individual per-channel operations.
*/
static void
lower_load_input_to_scalar(nir_builder *b, nir_intrinsic_instr *intr)
{
b->cursor = nir_before_instr(&intr->instr);
assert(intr->dest.is_ssa);
nir_ssa_def *loads[4];
for (unsigned i = 0; i < intr->num_components; i++) {
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;
nir_intrinsic_set_base(chan_intr, nir_intrinsic_base(intr));
nir_intrinsic_set_component(chan_intr, nir_intrinsic_component(intr) + i);
/* offset */
nir_src_copy(&chan_intr->src[0], &intr->src[0], chan_intr);
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)));
nir_instr_remove(&intr->instr);
}
static void
lower_store_output_to_scalar(nir_builder *b, nir_intrinsic_instr *intr)
{
b->cursor = nir_before_instr(&intr->instr);
nir_ssa_def *value = nir_ssa_for_src(b, intr->src[0], intr->num_components);
for (unsigned i = 0; i < intr->num_components; i++) {
if (!(nir_intrinsic_write_mask(intr) & (1 << i)))
continue;
nir_intrinsic_instr *chan_intr =
nir_intrinsic_instr_create(b->shader, intr->intrinsic);
chan_intr->num_components = 1;
nir_intrinsic_set_base(chan_intr, nir_intrinsic_base(intr));
nir_intrinsic_set_write_mask(chan_intr, 0x1);
nir_intrinsic_set_component(chan_intr, nir_intrinsic_component(intr) + i);
/* value */
chan_intr->src[0] = nir_src_for_ssa(nir_channel(b, value, i));
/* offset */
nir_src_copy(&chan_intr->src[1], &intr->src[1], chan_intr);
nir_builder_instr_insert(b, &chan_intr->instr);
}
nir_instr_remove(&intr->instr);
}
void
nir_lower_io_to_scalar(nir_shader *shader, nir_variable_mode mask)
{
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;
switch (intr->intrinsic) {
case nir_intrinsic_load_input:
if (mask & nir_var_shader_in)
lower_load_input_to_scalar(&b, intr);
break;
case nir_intrinsic_store_output:
if (mask & nir_var_shader_out)
lower_store_output_to_scalar(&b, intr);
break;
default:
break;
}
}
}
}
}
}
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);
}