mesa/src/compiler/nir/nir_lower_flatshade.c

84 lines
3.0 KiB
C

/*
* Copyright © 2015 Red Hat
*
* 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"
static bool
check_location(int location)
{
return location == VARYING_SLOT_COL0 ||
location == VARYING_SLOT_COL1 ||
location == VARYING_SLOT_BFC0 ||
location == VARYING_SLOT_BFC1;
}
static bool
lower_input(nir_shader *shader, nir_variable *var)
{
if (var->data.interpolation == INTERP_MODE_NONE &&
check_location(var->data.location))
var->data.interpolation = INTERP_MODE_FLAT;
return true;
}
static bool
lower_input_io(nir_builder *b, nir_intrinsic_instr *intr, void *data)
{
if (intr->intrinsic != nir_intrinsic_load_interpolated_input)
return false;;
nir_io_semantics sem = nir_intrinsic_io_semantics(intr);
if (!check_location(sem.location))
return false;
nir_def *interp = intr->src[0].ssa;
nir_intrinsic_instr *interp_intr = nir_instr_as_intrinsic(interp->parent_instr);
if (nir_intrinsic_interp_mode(interp_intr) != INTERP_MODE_NONE)
return false;
b->cursor = nir_before_instr(&intr->instr);
nir_def *load = nir_load_input(b, intr->num_components,
intr->def.bit_size, intr->src[1].ssa);
nir_intrinsic_instr *new_intr = nir_instr_as_intrinsic(load->parent_instr);
nir_intrinsic_copy_const_indices(new_intr, intr);
nir_def_rewrite_uses(&intr->def, load);
nir_instr_remove(&intr->instr);
return true;
}
bool
nir_lower_flatshade(nir_shader *shader)
{
bool progress = false;
if (shader->info.io_lowered) {
progress = nir_shader_intrinsics_pass(shader, lower_input_io,
nir_metadata_all, NULL);
} else {
nir_foreach_shader_in_variable(var, shader) {
progress |= lower_input(shader, var);
}
}
/* Interpolation doesn't affect any metadata */
nir_shader_preserve_all_metadata(shader);
return progress;
}