mesa/src/compiler/nir/nir_lower_point_size_mov.c

116 lines
4.5 KiB
C

/*
* Copyright © 2019 Collabora Ltd
*
* 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"
/** nir_lower_point_size_mov.c
*
* This pass lowers glPointSize into gl_PointSize, by adding a uniform
* and a move from that uniform to VARYING_SLOT_PSIZ. This is useful for
* OpenGL ES level hardware that lack constant point-size hardware state.
*/
static bool
lower_impl(nir_function_impl *impl,
const gl_state_index16 *pointsize_state_tokens,
nir_variable *out)
{
nir_shader *shader = impl->function->shader;
nir_builder b;
nir_variable *in, *new_out = NULL;
nir_builder_init(&b, impl);
in = nir_variable_create(shader, nir_var_uniform,
glsl_vec4_type(), "gl_PointSizeClampedMESA");
in->num_state_slots = 1;
in->state_slots = ralloc_array(in, nir_state_slot, 1);
in->state_slots[0].swizzle = BITFIELD_MASK(4);
memcpy(in->state_slots[0].tokens,
pointsize_state_tokens,
sizeof(in->state_slots[0].tokens));
/* the existing output can't be removed in order to avoid breaking xfb.
* drivers must check var->data.explicit_location to find the original output
* and only emit that one for xfb
*/
if (!out || out->data.explicit_location) {
new_out = nir_variable_create(shader, nir_var_shader_out,
glsl_float_type(), "gl_PointSizeMESA");
new_out->data.location = VARYING_SLOT_PSIZ;
}
if (!out) {
b.cursor = nir_before_cf_list(&impl->body);
nir_ssa_def *load = nir_load_var(&b, in);
load = nir_fclamp(&b, nir_channel(&b, load, 0), nir_channel(&b, load, 1), nir_channel(&b, load, 2));
nir_store_var(&b, new_out, load, 0x1);
} else {
bool found = false;
nir_foreach_block_safe(block, impl) {
nir_foreach_instr_safe(instr, block) {
if (instr->type == nir_instr_type_intrinsic) {
nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
if (intr->intrinsic == nir_intrinsic_store_deref) {
nir_variable *var = nir_intrinsic_get_var(intr, 0);
if (var == out) {
b.cursor = nir_after_instr(instr);
nir_ssa_def *load = nir_load_var(&b, in);
load = nir_fclamp(&b, nir_channel(&b, load, 0), nir_channel(&b, load, 1), nir_channel(&b, load, 2));
nir_store_var(&b, new_out ? new_out : out, load, 0x1);
found = true;
}
}
}
}
}
if (!found) {
b.cursor = nir_before_cf_list(&impl->body);
nir_ssa_def *load = nir_load_var(&b, in);
load = nir_fclamp(&b, nir_channel(&b, load, 0), nir_channel(&b, load, 1), nir_channel(&b, load, 2));
nir_store_var(&b, new_out, load, 0x1);
}
}
nir_metadata_preserve(impl, nir_metadata_block_index |
nir_metadata_dominance);
return true;
}
void
nir_lower_point_size_mov(nir_shader *shader,
const gl_state_index16 *pointsize_state_tokens)
{
assert(shader->info.stage != MESA_SHADER_FRAGMENT &&
shader->info.stage != MESA_SHADER_COMPUTE);
nir_variable *out =
nir_find_variable_with_location(shader, nir_var_shader_out,
VARYING_SLOT_PSIZ);
lower_impl(nir_shader_get_entrypoint(shader), pointsize_state_tokens,
out);
}