1 /*
2 * Copyright © 2016 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 /* Lowers the additional tex_src_plane src, generated by nir_lower_tex
25 * for planar YUV textures, into separate samplers, matching the logic
26 * that mesa/st uses to insert additional sampler view/state (since both
27 * sides need to agree).
28 *
29 * This should run after nir_lower_samplers.
30 */
31
32 #include "util/u_string.h"
33 #include "compiler/nir/nir.h"
34 #include "compiler/nir/nir_builder.h"
35 #include "st_nir.h"
36
37 typedef struct {
38 struct nir_shader *shader;
39
40 unsigned lower_2plane;
41 unsigned lower_3plane;
42
43 /* Maps a primary sampler (used for Y) to the U or UV sampler. In
44 * case of 3-plane YUV format, the V plane is next sampler after U.
45 */
46 unsigned char sampler_map[PIPE_MAX_SAMPLERS][2];
47 } lower_tex_src_state;
48
49 static nir_variable *
find_sampler(lower_tex_src_state * state,unsigned samp)50 find_sampler(lower_tex_src_state *state, unsigned samp)
51 {
52 /* NOTE: arrays of samplerExternalOES do not appear to be allowed: */
53 nir_foreach_uniform_variable(var, state->shader)
54 if (var->data.binding == samp)
55 return var;
56 return NULL;
57 }
58
59 static void
add_sampler(lower_tex_src_state * state,unsigned orig_binding,unsigned new_binding,const char * ext)60 add_sampler(lower_tex_src_state *state, unsigned orig_binding,
61 unsigned new_binding, const char *ext)
62 {
63 const struct glsl_type *samplerExternalOES =
64 glsl_sampler_type(GLSL_SAMPLER_DIM_EXTERNAL, false, false, GLSL_TYPE_FLOAT);
65 nir_variable *new_sampler, *orig_sampler =
66 find_sampler(state, orig_binding);
67 char *name;
68
69 UNUSED int r = asprintf(&name, "%s:%s", orig_sampler->name, ext);
70 new_sampler = nir_variable_create(state->shader, nir_var_uniform,
71 samplerExternalOES, name);
72 free(name);
73
74 new_sampler->data.binding = new_binding;
75 }
76
77 static void
assign_extra_samplers(lower_tex_src_state * state,unsigned free_slots)78 assign_extra_samplers(lower_tex_src_state *state, unsigned free_slots)
79 {
80 unsigned mask = state->lower_2plane | state->lower_3plane;
81
82 while (mask) {
83 unsigned extra, y_samp = u_bit_scan(&mask);
84
85 if (state->lower_3plane & (1 << y_samp)) {
86 /* two additional planes (U and V): */
87 extra = u_bit_scan(&free_slots);
88 state->sampler_map[y_samp][0] = extra;
89
90 add_sampler(state, y_samp, extra, "u");
91
92 extra = u_bit_scan(&free_slots);
93 state->sampler_map[y_samp][1] = extra;
94
95 add_sampler(state, y_samp, extra, "v");
96 } else {
97 /* single additional UV plane: */
98 extra = u_bit_scan(&free_slots);
99 state->sampler_map[y_samp][0] = extra;
100
101 add_sampler(state, y_samp, extra, "uv");
102 }
103 }
104 }
105
106 static void
lower_tex_src_plane_block(nir_builder * b,lower_tex_src_state * state,nir_block * block)107 lower_tex_src_plane_block(nir_builder *b, lower_tex_src_state *state, nir_block *block)
108 {
109 nir_foreach_instr(instr, block) {
110 if (instr->type != nir_instr_type_tex)
111 continue;
112
113 nir_tex_instr *tex = nir_instr_as_tex(instr);
114 int plane_index = nir_tex_instr_src_index(tex, nir_tex_src_plane);
115
116 if (plane_index < 0)
117 continue;
118
119 nir_const_value *plane = nir_src_as_const_value(tex->src[plane_index].src);
120 assume(plane);
121
122 if (plane[0].i32 > 0) {
123 unsigned y_samp = tex->texture_index;
124 int tex_index = nir_tex_instr_src_index(tex, nir_tex_src_texture_deref);
125 if (tex_index >= 0) {
126 nir_deref_instr *deref = nir_src_as_deref(tex->src[tex_index].src);
127 y_samp = nir_deref_instr_get_variable(deref)->data.binding;
128 }
129
130 assume(((state->lower_3plane & (1 << y_samp)) && plane[0].i32 < 3) ||
131 (plane[0].i32 < 2));
132
133 unsigned u_v_samp = state->sampler_map[y_samp][plane[0].i32 - 1];
134 BITSET_SET(state->shader->info.textures_used, u_v_samp);
135 BITSET_SET(state->shader->info.samplers_used, u_v_samp);
136
137 /* For drivers using PIPE_CAP_NIR_SAMPLERS_AS_DEREF, we need
138 * to reference the correct sampler nir variable.
139 */
140 int samp_index = nir_tex_instr_src_index(tex, nir_tex_src_sampler_deref);
141 if (tex_index >= 0 && samp_index >= 0) {
142 b->cursor = nir_before_instr(&tex->instr);
143
144 nir_variable* samp = find_sampler(state, u_v_samp);
145 assert(samp);
146
147 nir_deref_instr *tex_deref_instr = nir_build_deref_var(b, samp);
148 nir_ssa_def *tex_deref = &tex_deref_instr->dest.ssa;
149
150 nir_instr_rewrite_src(&tex->instr,
151 &tex->src[tex_index].src,
152 nir_src_for_ssa(tex_deref));
153 nir_instr_rewrite_src(&tex->instr,
154 &tex->src[samp_index].src,
155 nir_src_for_ssa(tex_deref));
156 } else {
157 /* For others we need to update texture_index */
158 assume(tex->texture_index == tex->sampler_index);
159 tex->texture_index = tex->sampler_index = u_v_samp;
160 }
161 }
162
163 nir_tex_instr_remove_src(tex, plane_index);
164 }
165 }
166
167 static void
lower_tex_src_plane_impl(lower_tex_src_state * state,nir_function_impl * impl)168 lower_tex_src_plane_impl(lower_tex_src_state *state, nir_function_impl *impl)
169 {
170 nir_builder b;
171 nir_builder_init(&b, impl);
172
173 nir_foreach_block(block, impl) {
174 lower_tex_src_plane_block(&b, state, block);
175 }
176
177 nir_metadata_preserve(impl, nir_metadata_block_index |
178 nir_metadata_dominance);
179 }
180
181 void
st_nir_lower_tex_src_plane(struct nir_shader * shader,unsigned free_slots,unsigned lower_2plane,unsigned lower_3plane)182 st_nir_lower_tex_src_plane(struct nir_shader *shader, unsigned free_slots,
183 unsigned lower_2plane, unsigned lower_3plane)
184 {
185 lower_tex_src_state state = {0};
186
187 state.shader = shader;
188 state.lower_2plane = lower_2plane;
189 state.lower_3plane = lower_3plane;
190
191 assign_extra_samplers(&state, free_slots);
192
193 nir_foreach_function(function, shader) {
194 if (function->impl)
195 lower_tex_src_plane_impl(&state, function->impl);
196 }
197 }
198