1 /*
2 * Copyright © 2016 Red Hat.
3 * Copyright © 2016 Bas Nieuwenhuizen
4 * Copyright © 2023 Valve Corporation
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the next
14 * paragraph) shall be included in all copies or substantial portions of the
15 * Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
23 * IN THE SOFTWARE.
24 */
25
26 #include "nir.h"
27 #include "nir_builder.h"
28 #include "radv_nir.h"
29
30 static nir_variable *
find_layer_out_var(nir_shader * nir)31 find_layer_out_var(nir_shader *nir)
32 {
33 nir_variable *var = nir_find_variable_with_location(nir, nir_var_shader_out, VARYING_SLOT_LAYER);
34 if (var != NULL)
35 return var;
36
37 var = nir_variable_create(nir, nir_var_shader_out, glsl_int_type(), "layer id");
38 var->data.location = VARYING_SLOT_LAYER;
39 var->data.interpolation = INTERP_MODE_NONE;
40
41 return var;
42 }
43
44 bool
radv_nir_export_multiview(nir_shader * nir)45 radv_nir_export_multiview(nir_shader *nir)
46 {
47 nir_function_impl *impl = nir_shader_get_entrypoint(nir);
48 bool progress = false;
49
50 nir_builder b = nir_builder_create(impl);
51
52 /* This pass is not suitable for mesh shaders, because it can't know the mapping between API mesh
53 * shader invocations and output primitives. Needs to be handled in ac_nir_lower_ngg.
54 */
55 assert(nir->info.stage == MESA_SHADER_VERTEX || nir->info.stage == MESA_SHADER_TESS_EVAL ||
56 nir->info.stage == MESA_SHADER_GEOMETRY);
57
58 /* Iterate in reverse order since there should be only one deref store to POS after
59 * lower_io_to_temporaries for vertex shaders and inject the layer there. For geometry shaders,
60 * the layer is injected right before every emit_vertex_with_counter.
61 */
62 nir_variable *layer = NULL;
63 nir_foreach_block_reverse (block, impl) {
64 nir_foreach_instr_reverse (instr, block) {
65 if (instr->type != nir_instr_type_intrinsic)
66 continue;
67
68 if (nir->info.stage == MESA_SHADER_GEOMETRY) {
69 nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
70 if (intr->intrinsic != nir_intrinsic_emit_vertex_with_counter)
71 continue;
72
73 b.cursor = nir_before_instr(instr);
74 } else {
75 nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
76 if (intr->intrinsic != nir_intrinsic_store_deref)
77 continue;
78
79 nir_variable *var = nir_intrinsic_get_var(intr, 0);
80 if (var->data.mode != nir_var_shader_out || var->data.location != VARYING_SLOT_POS)
81 continue;
82
83 b.cursor = nir_after_instr(instr);
84 }
85
86 if (!layer)
87 layer = find_layer_out_var(nir);
88
89 nir_store_var(&b, layer, nir_load_view_index(&b), 1);
90
91 /* Update outputs_written to reflect that the pass added a new output. */
92 nir->info.outputs_written |= BITFIELD64_BIT(VARYING_SLOT_LAYER);
93
94 progress = true;
95 if (nir->info.stage == MESA_SHADER_VERTEX)
96 break;
97 }
98 if (nir->info.stage == MESA_SHADER_VERTEX && progress)
99 break;
100 }
101
102 if (progress)
103 nir_metadata_preserve(impl, nir_metadata_block_index | nir_metadata_dominance);
104 else
105 nir_metadata_preserve(impl, nir_metadata_all);
106
107 return progress;
108 }
109