1 /*
2 * Copyright © 2016 Broadcom
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
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24 #include "nir.h"
25 #include "nir_builder.h"
26
27 /** @file nir_lower_io_to_scalar.c
28 *
29 * Replaces nir_load_input/nir_store_output operations with num_components !=
30 * 1 with individual per-channel operations.
31 */
32
33 static void
lower_load_input_to_scalar(nir_builder * b,nir_intrinsic_instr * intr)34 lower_load_input_to_scalar(nir_builder *b, nir_intrinsic_instr *intr)
35 {
36 b->cursor = nir_before_instr(&intr->instr);
37
38 assert(intr->dest.is_ssa);
39
40 nir_ssa_def *loads[4];
41
42 for (unsigned i = 0; i < intr->num_components; i++) {
43 nir_intrinsic_instr *chan_intr =
44 nir_intrinsic_instr_create(b->shader, intr->intrinsic);
45 nir_ssa_dest_init(&chan_intr->instr, &chan_intr->dest,
46 1, intr->dest.ssa.bit_size, NULL);
47 chan_intr->num_components = 1;
48
49 nir_intrinsic_set_base(chan_intr, nir_intrinsic_base(intr));
50 nir_intrinsic_set_component(chan_intr, nir_intrinsic_component(intr) + i);
51 /* offset */
52 nir_src_copy(&chan_intr->src[0], &intr->src[0], chan_intr);
53
54 nir_builder_instr_insert(b, &chan_intr->instr);
55
56 loads[i] = &chan_intr->dest.ssa;
57 }
58
59 nir_ssa_def_rewrite_uses(&intr->dest.ssa,
60 nir_src_for_ssa(nir_vec(b, loads,
61 intr->num_components)));
62 nir_instr_remove(&intr->instr);
63 }
64
65 static void
lower_store_output_to_scalar(nir_builder * b,nir_intrinsic_instr * intr)66 lower_store_output_to_scalar(nir_builder *b, nir_intrinsic_instr *intr)
67 {
68 b->cursor = nir_before_instr(&intr->instr);
69
70 nir_ssa_def *value = nir_ssa_for_src(b, intr->src[0], intr->num_components);
71
72 for (unsigned i = 0; i < intr->num_components; i++) {
73 if (!(nir_intrinsic_write_mask(intr) & (1 << i)))
74 continue;
75
76 nir_intrinsic_instr *chan_intr =
77 nir_intrinsic_instr_create(b->shader, intr->intrinsic);
78 chan_intr->num_components = 1;
79
80 nir_intrinsic_set_base(chan_intr, nir_intrinsic_base(intr));
81 nir_intrinsic_set_write_mask(chan_intr, 0x1);
82 nir_intrinsic_set_component(chan_intr, nir_intrinsic_component(intr) + i);
83
84 /* value */
85 chan_intr->src[0] = nir_src_for_ssa(nir_channel(b, value, i));
86 /* offset */
87 nir_src_copy(&chan_intr->src[1], &intr->src[1], chan_intr);
88
89 nir_builder_instr_insert(b, &chan_intr->instr);
90 }
91
92 nir_instr_remove(&intr->instr);
93 }
94
95 void
nir_lower_io_to_scalar(nir_shader * shader,nir_variable_mode mask)96 nir_lower_io_to_scalar(nir_shader *shader, nir_variable_mode mask)
97 {
98 nir_foreach_function(function, shader) {
99 if (function->impl) {
100 nir_builder b;
101 nir_builder_init(&b, function->impl);
102
103 nir_foreach_block(block, function->impl) {
104 nir_foreach_instr_safe(instr, block) {
105 if (instr->type != nir_instr_type_intrinsic)
106 continue;
107
108 nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
109
110 if (intr->num_components == 1)
111 continue;
112
113 switch (intr->intrinsic) {
114 case nir_intrinsic_load_input:
115 if (mask & nir_var_shader_in)
116 lower_load_input_to_scalar(&b, intr);
117 break;
118 case nir_intrinsic_store_output:
119 if (mask & nir_var_shader_out)
120 lower_store_output_to_scalar(&b, intr);
121 break;
122 default:
123 break;
124 }
125 }
126 }
127 }
128 }
129 }
130
131 static nir_variable **
get_channel_variables(struct hash_table * ht,nir_variable * var)132 get_channel_variables(struct hash_table *ht, nir_variable *var)
133 {
134 nir_variable **chan_vars;
135 struct hash_entry *entry = _mesa_hash_table_search(ht, var);
136 if (!entry) {
137 chan_vars = (nir_variable **) calloc(4, sizeof(nir_variable *));
138 _mesa_hash_table_insert(ht, var, chan_vars);
139 } else {
140 chan_vars = (nir_variable **) entry->data;
141 }
142
143 return chan_vars;
144 }
145
146 /*
147 * This function differs from nir_deref_clone() in that it gets its type from
148 * the parent deref rather than our source deref. This is useful when splitting
149 * vectors because we want to use the scalar type of the new parent rather than
150 * then the old vector type.
151 */
152 static nir_deref_array *
clone_deref_array(const nir_deref_array * darr,nir_deref * parent)153 clone_deref_array(const nir_deref_array *darr, nir_deref *parent)
154 {
155 nir_deref_array *ndarr = nir_deref_array_create(parent);
156
157 ndarr->deref.type = glsl_get_array_element(parent->type);
158 if (darr->deref.child)
159 ndarr->deref.child =
160 &clone_deref_array(nir_deref_as_array(darr->deref.child),
161 &ndarr->deref)->deref;
162
163 ndarr->deref_array_type = darr->deref_array_type;
164 ndarr->base_offset = darr->base_offset;
165 if (ndarr->deref_array_type == nir_deref_array_type_indirect)
166 nir_src_copy(&ndarr->indirect, &darr->indirect, parent);
167
168 return ndarr;
169 }
170
171 static void
lower_load_to_scalar_early(nir_builder * b,nir_intrinsic_instr * intr,nir_variable * var,struct hash_table * split_inputs,struct hash_table * split_outputs)172 lower_load_to_scalar_early(nir_builder *b, nir_intrinsic_instr *intr,
173 nir_variable *var, struct hash_table *split_inputs,
174 struct hash_table *split_outputs)
175 {
176 b->cursor = nir_before_instr(&intr->instr);
177
178 assert(intr->dest.is_ssa);
179
180 nir_ssa_def *loads[4];
181
182 nir_variable **chan_vars;
183 if (var->data.mode == nir_var_shader_in) {
184 chan_vars = get_channel_variables(split_inputs, var);
185 } else {
186 chan_vars = get_channel_variables(split_outputs, var);
187 }
188
189 for (unsigned i = 0; i < intr->num_components; i++) {
190 nir_variable *chan_var = chan_vars[var->data.location_frac + i];
191 if (!chan_vars[var->data.location_frac + i]) {
192 chan_var = nir_variable_clone(var, b->shader);
193 chan_var->data.location_frac = var->data.location_frac + i;
194 chan_var->type = glsl_channel_type(chan_var->type);
195
196 chan_vars[var->data.location_frac + i] = chan_var;
197
198 nir_shader_add_variable(b->shader, chan_var);
199 }
200
201 nir_intrinsic_instr *chan_intr =
202 nir_intrinsic_instr_create(b->shader, intr->intrinsic);
203 nir_ssa_dest_init(&chan_intr->instr, &chan_intr->dest,
204 1, intr->dest.ssa.bit_size, NULL);
205 chan_intr->num_components = 1;
206 chan_intr->variables[0] = nir_deref_var_create(chan_intr, chan_var);
207
208 if (intr->variables[0]->deref.child) {
209 chan_intr->variables[0]->deref.child =
210 &clone_deref_array(nir_deref_as_array(intr->variables[0]->deref.child),
211 &chan_intr->variables[0]->deref)->deref;
212 }
213
214 if (intr->intrinsic == nir_intrinsic_interp_var_at_offset ||
215 intr->intrinsic == nir_intrinsic_interp_var_at_sample)
216 nir_src_copy(chan_intr->src, intr->src, &chan_intr->instr);
217
218 nir_builder_instr_insert(b, &chan_intr->instr);
219
220 loads[i] = &chan_intr->dest.ssa;
221 }
222
223 nir_ssa_def_rewrite_uses(&intr->dest.ssa,
224 nir_src_for_ssa(nir_vec(b, loads,
225 intr->num_components)));
226
227 /* Remove the old load intrinsic */
228 nir_instr_remove(&intr->instr);
229 }
230
231 static void
lower_store_output_to_scalar_early(nir_builder * b,nir_intrinsic_instr * intr,nir_variable * var,struct hash_table * split_outputs)232 lower_store_output_to_scalar_early(nir_builder *b, nir_intrinsic_instr *intr,
233 nir_variable *var,
234 struct hash_table *split_outputs)
235 {
236 b->cursor = nir_before_instr(&intr->instr);
237
238 nir_ssa_def *value = nir_ssa_for_src(b, intr->src[0], intr->num_components);
239
240 nir_variable **chan_vars = get_channel_variables(split_outputs, var);
241 for (unsigned i = 0; i < intr->num_components; i++) {
242 if (!(nir_intrinsic_write_mask(intr) & (1 << i)))
243 continue;
244
245 nir_variable *chan_var = chan_vars[var->data.location_frac + i];
246 if (!chan_vars[var->data.location_frac + i]) {
247 chan_var = nir_variable_clone(var, b->shader);
248 chan_var->data.location_frac = var->data.location_frac + i;
249 chan_var->type = glsl_channel_type(chan_var->type);
250
251 chan_vars[var->data.location_frac + i] = chan_var;
252
253 nir_shader_add_variable(b->shader, chan_var);
254 }
255
256 nir_intrinsic_instr *chan_intr =
257 nir_intrinsic_instr_create(b->shader, intr->intrinsic);
258 chan_intr->num_components = 1;
259
260 nir_intrinsic_set_write_mask(chan_intr, 0x1);
261
262 chan_intr->variables[0] = nir_deref_var_create(chan_intr, chan_var);
263 chan_intr->src[0] = nir_src_for_ssa(nir_channel(b, value, i));
264
265 if (intr->variables[0]->deref.child) {
266 chan_intr->variables[0]->deref.child =
267 &clone_deref_array(nir_deref_as_array(intr->variables[0]->deref.child),
268 &chan_intr->variables[0]->deref)->deref;
269 }
270
271 nir_builder_instr_insert(b, &chan_intr->instr);
272 }
273
274 /* Remove the old store intrinsic */
275 nir_instr_remove(&intr->instr);
276 }
277
278 /*
279 * This function is intended to be called earlier than nir_lower_io_to_scalar()
280 * i.e. before nir_lower_io() is called.
281 */
282 void
nir_lower_io_to_scalar_early(nir_shader * shader,nir_variable_mode mask)283 nir_lower_io_to_scalar_early(nir_shader *shader, nir_variable_mode mask)
284 {
285 struct hash_table *split_inputs =
286 _mesa_hash_table_create(NULL, _mesa_hash_pointer,
287 _mesa_key_pointer_equal);
288 struct hash_table *split_outputs =
289 _mesa_hash_table_create(NULL, _mesa_hash_pointer,
290 _mesa_key_pointer_equal);
291
292 nir_foreach_function(function, shader) {
293 if (function->impl) {
294 nir_builder b;
295 nir_builder_init(&b, function->impl);
296
297 nir_foreach_block(block, function->impl) {
298 nir_foreach_instr_safe(instr, block) {
299 if (instr->type != nir_instr_type_intrinsic)
300 continue;
301
302 nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
303
304 if (intr->num_components == 1)
305 continue;
306
307 if (intr->intrinsic != nir_intrinsic_load_var &&
308 intr->intrinsic != nir_intrinsic_store_var &&
309 intr->intrinsic != nir_intrinsic_interp_var_at_centroid &&
310 intr->intrinsic != nir_intrinsic_interp_var_at_sample &&
311 intr->intrinsic != nir_intrinsic_interp_var_at_offset)
312 continue;
313
314 nir_variable *var = intr->variables[0]->var;
315 nir_variable_mode mode = var->data.mode;
316
317 /* TODO: add patch support */
318 if (var->data.patch)
319 continue;
320
321 /* TODO: add doubles support */
322 if (glsl_type_is_64bit(glsl_without_array(var->type)))
323 continue;
324
325 if (var->data.location < VARYING_SLOT_VAR0 &&
326 var->data.location >= 0)
327 continue;
328
329 /* Don't bother splitting if we can't opt away any unused
330 * components.
331 */
332 if (var->data.always_active_io)
333 continue;
334
335 /* Skip types we cannot split */
336 if (glsl_type_is_matrix(glsl_without_array(var->type)) ||
337 glsl_type_is_struct(glsl_without_array(var->type)))
338 continue;
339
340 switch (intr->intrinsic) {
341 case nir_intrinsic_interp_var_at_centroid:
342 case nir_intrinsic_interp_var_at_sample:
343 case nir_intrinsic_interp_var_at_offset:
344 case nir_intrinsic_load_var:
345 if ((mask & nir_var_shader_in && mode == nir_var_shader_in) ||
346 (mask & nir_var_shader_out && mode == nir_var_shader_out))
347 lower_load_to_scalar_early(&b, intr, var, split_inputs,
348 split_outputs);
349 break;
350 case nir_intrinsic_store_var:
351 if (mask & nir_var_shader_out &&
352 mode == nir_var_shader_out)
353 lower_store_output_to_scalar_early(&b, intr, var,
354 split_outputs);
355 break;
356 default:
357 break;
358 }
359 }
360 }
361 }
362 }
363
364 /* Remove old input from the shaders inputs list */
365 struct hash_entry *entry;
366 hash_table_foreach(split_inputs, entry) {
367 nir_variable *var = (nir_variable *) entry->key;
368 exec_node_remove(&var->node);
369
370 free(entry->data);
371 }
372
373 /* Remove old output from the shaders outputs list */
374 hash_table_foreach(split_outputs, entry) {
375 nir_variable *var = (nir_variable *) entry->key;
376 exec_node_remove(&var->node);
377
378 free(entry->data);
379 }
380
381 _mesa_hash_table_destroy(split_inputs, NULL);
382 _mesa_hash_table_destroy(split_outputs, NULL);
383 }
384