1 /*
2 * Copyright © 2015 Red Hat
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 * SOFTWARE.
22 */
23
24 #include "nir.h"
25 #include "nir_builder.h"
26
27 static bool
check_location(int location)28 check_location(int location)
29 {
30 return location == VARYING_SLOT_COL0 ||
31 location == VARYING_SLOT_COL1 ||
32 location == VARYING_SLOT_BFC0 ||
33 location == VARYING_SLOT_BFC1;
34 }
35
36 static bool
lower_input(nir_shader * shader,nir_variable * var)37 lower_input(nir_shader *shader, nir_variable *var)
38 {
39 if (var->data.interpolation == INTERP_MODE_NONE &&
40 check_location(var->data.location))
41 var->data.interpolation = INTERP_MODE_FLAT;
42 return true;
43 }
44
45 static bool
lower_input_io(nir_builder * b,nir_intrinsic_instr * intr,void * data)46 lower_input_io(nir_builder *b, nir_intrinsic_instr *intr, void *data)
47 {
48 if (intr->intrinsic != nir_intrinsic_load_interpolated_input)
49 return false;;
50 nir_io_semantics sem = nir_intrinsic_io_semantics(intr);
51 if (!check_location(sem.location))
52 return false;
53 nir_def *interp = intr->src[0].ssa;
54 nir_intrinsic_instr *interp_intr = nir_instr_as_intrinsic(interp->parent_instr);
55 if (nir_intrinsic_interp_mode(interp_intr) != INTERP_MODE_NONE)
56 return false;
57 b->cursor = nir_before_instr(&intr->instr);
58 nir_def *load = nir_load_input(b, intr->num_components,
59 intr->def.bit_size, intr->src[1].ssa);
60 nir_intrinsic_instr *new_intr = nir_instr_as_intrinsic(load->parent_instr);
61 nir_intrinsic_copy_const_indices(new_intr, intr);
62 nir_def_replace(&intr->def, load);
63 return true;
64 }
65 bool
nir_lower_flatshade(nir_shader * shader)66 nir_lower_flatshade(nir_shader *shader)
67 {
68 bool progress = false;
69
70 if (shader->info.io_lowered) {
71 progress = nir_shader_intrinsics_pass(shader, lower_input_io,
72 nir_metadata_all, NULL);
73 } else {
74 nir_foreach_shader_in_variable(var, shader) {
75 progress |= lower_input(shader, var);
76 }
77 }
78
79 /* Interpolation doesn't affect any metadata */
80 nir_shader_preserve_all_metadata(shader);
81 return progress;
82 }
83