1 /*
2 * Copyright © 2013 Intel Corporation
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
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24 /**
25 * \file brw_vec4_tcs.cpp
26 *
27 * Tessellaton control shader specific code derived from the vec4_visitor class.
28 */
29
30 #include "brw_nir.h"
31 #include "brw_vec4_tcs.h"
32 #include "brw_fs.h"
33 #include "common/gen_debug.h"
34
35 namespace brw {
36
vec4_tcs_visitor(const struct brw_compiler * compiler,void * log_data,const struct brw_tcs_prog_key * key,struct brw_tcs_prog_data * prog_data,const nir_shader * nir,void * mem_ctx,int shader_time_index,const struct brw_vue_map * input_vue_map)37 vec4_tcs_visitor::vec4_tcs_visitor(const struct brw_compiler *compiler,
38 void *log_data,
39 const struct brw_tcs_prog_key *key,
40 struct brw_tcs_prog_data *prog_data,
41 const nir_shader *nir,
42 void *mem_ctx,
43 int shader_time_index,
44 const struct brw_vue_map *input_vue_map)
45 : vec4_visitor(compiler, log_data, &key->tex, &prog_data->base,
46 nir, mem_ctx, false, shader_time_index),
47 input_vue_map(input_vue_map), key(key)
48 {
49 }
50
51
52 void
setup_payload()53 vec4_tcs_visitor::setup_payload()
54 {
55 int reg = 0;
56
57 /* The payload always contains important data in r0, which contains
58 * the URB handles that are passed on to the URB write at the end
59 * of the thread.
60 */
61 reg++;
62
63 /* r1.0 - r4.7 may contain the input control point URB handles,
64 * which we use to pull vertex data.
65 */
66 reg += 4;
67
68 /* Push constants may start at r5.0 */
69 reg = setup_uniforms(reg);
70
71 this->first_non_payload_grf = reg;
72 }
73
74
75 void
emit_prolog()76 vec4_tcs_visitor::emit_prolog()
77 {
78 invocation_id = src_reg(this, glsl_type::uint_type);
79 emit(TCS_OPCODE_GET_INSTANCE_ID, dst_reg(invocation_id));
80
81 /* HS threads are dispatched with the dispatch mask set to 0xFF.
82 * If there are an odd number of output vertices, then the final
83 * HS instance dispatched will only have its bottom half doing real
84 * work, and so we need to disable the upper half:
85 */
86 if (nir->info.tess.tcs_vertices_out % 2) {
87 emit(CMP(dst_null_d(), invocation_id,
88 brw_imm_ud(nir->info.tess.tcs_vertices_out),
89 BRW_CONDITIONAL_L));
90
91 /* Matching ENDIF is in emit_thread_end() */
92 emit(IF(BRW_PREDICATE_NORMAL));
93 }
94 }
95
96
97 void
emit_thread_end()98 vec4_tcs_visitor::emit_thread_end()
99 {
100 vec4_instruction *inst;
101 current_annotation = "thread end";
102
103 if (nir->info.tess.tcs_vertices_out % 2) {
104 emit(BRW_OPCODE_ENDIF);
105 }
106
107 if (devinfo->gen == 7) {
108 struct brw_tcs_prog_data *tcs_prog_data =
109 (struct brw_tcs_prog_data *) prog_data;
110
111 current_annotation = "release input vertices";
112
113 /* Synchronize all threads, so we know that no one is still
114 * using the input URB handles.
115 */
116 if (tcs_prog_data->instances > 1) {
117 dst_reg header = dst_reg(this, glsl_type::uvec4_type);
118 emit(TCS_OPCODE_CREATE_BARRIER_HEADER, header);
119 emit(SHADER_OPCODE_BARRIER, dst_null_ud(), src_reg(header));
120 }
121
122 /* Make thread 0 (invocations <1, 0>) release pairs of ICP handles.
123 * We want to compare the bottom half of invocation_id with 0, but
124 * use that truth value for the top half as well. Unfortunately,
125 * we don't have stride in the vec4 world, nor UV immediates in
126 * align16, so we need an opcode to get invocation_id<0,4,0>.
127 */
128 set_condmod(BRW_CONDITIONAL_Z,
129 emit(TCS_OPCODE_SRC0_010_IS_ZERO, dst_null_d(),
130 invocation_id));
131 emit(IF(BRW_PREDICATE_NORMAL));
132 for (unsigned i = 0; i < key->input_vertices; i += 2) {
133 /* If we have an odd number of input vertices, the last will be
134 * unpaired. We don't want to use an interleaved URB write in
135 * that case.
136 */
137 const bool is_unpaired = i == key->input_vertices - 1;
138
139 dst_reg header(this, glsl_type::uvec4_type);
140 emit(TCS_OPCODE_RELEASE_INPUT, header, brw_imm_ud(i),
141 brw_imm_ud(is_unpaired));
142 }
143 emit(BRW_OPCODE_ENDIF);
144 }
145
146 if (unlikely(INTEL_DEBUG & DEBUG_SHADER_TIME))
147 emit_shader_time_end();
148
149 inst = emit(TCS_OPCODE_THREAD_END);
150 inst->base_mrf = 14;
151 inst->mlen = 2;
152 }
153
154
155 void
emit_input_urb_read(const dst_reg & dst,const src_reg & vertex_index,unsigned base_offset,unsigned first_component,const src_reg & indirect_offset)156 vec4_tcs_visitor::emit_input_urb_read(const dst_reg &dst,
157 const src_reg &vertex_index,
158 unsigned base_offset,
159 unsigned first_component,
160 const src_reg &indirect_offset)
161 {
162 vec4_instruction *inst;
163 dst_reg temp(this, glsl_type::ivec4_type);
164 temp.type = dst.type;
165
166 /* Set up the message header to reference the proper parts of the URB */
167 dst_reg header = dst_reg(this, glsl_type::uvec4_type);
168 inst = emit(TCS_OPCODE_SET_INPUT_URB_OFFSETS, header, vertex_index,
169 indirect_offset);
170 inst->force_writemask_all = true;
171
172 /* Read into a temporary, ignoring writemasking. */
173 inst = emit(VEC4_OPCODE_URB_READ, temp, src_reg(header));
174 inst->offset = base_offset;
175 inst->mlen = 1;
176 inst->base_mrf = -1;
177
178 /* Copy the temporary to the destination to deal with writemasking.
179 *
180 * Also attempt to deal with gl_PointSize being in the .w component.
181 */
182 if (inst->offset == 0 && indirect_offset.file == BAD_FILE) {
183 emit(MOV(dst, swizzle(src_reg(temp), BRW_SWIZZLE_WWWW)));
184 } else {
185 src_reg src = src_reg(temp);
186 src.swizzle = BRW_SWZ_COMP_INPUT(first_component);
187 emit(MOV(dst, src));
188 }
189 }
190
191 void
emit_output_urb_read(const dst_reg & dst,unsigned base_offset,unsigned first_component,const src_reg & indirect_offset)192 vec4_tcs_visitor::emit_output_urb_read(const dst_reg &dst,
193 unsigned base_offset,
194 unsigned first_component,
195 const src_reg &indirect_offset)
196 {
197 vec4_instruction *inst;
198
199 /* Set up the message header to reference the proper parts of the URB */
200 dst_reg header = dst_reg(this, glsl_type::uvec4_type);
201 inst = emit(TCS_OPCODE_SET_OUTPUT_URB_OFFSETS, header,
202 brw_imm_ud(dst.writemask << first_component), indirect_offset);
203 inst->force_writemask_all = true;
204
205 vec4_instruction *read = emit(VEC4_OPCODE_URB_READ, dst, src_reg(header));
206 read->offset = base_offset;
207 read->mlen = 1;
208 read->base_mrf = -1;
209
210 if (first_component) {
211 /* Read into a temporary and copy with a swizzle and writemask. */
212 read->dst = retype(dst_reg(this, glsl_type::ivec4_type), dst.type);
213 emit(MOV(dst, swizzle(src_reg(read->dst),
214 BRW_SWZ_COMP_INPUT(first_component))));
215 }
216 }
217
218 void
emit_urb_write(const src_reg & value,unsigned writemask,unsigned base_offset,const src_reg & indirect_offset)219 vec4_tcs_visitor::emit_urb_write(const src_reg &value,
220 unsigned writemask,
221 unsigned base_offset,
222 const src_reg &indirect_offset)
223 {
224 if (writemask == 0)
225 return;
226
227 src_reg message(this, glsl_type::uvec4_type, 2);
228 vec4_instruction *inst;
229
230 inst = emit(TCS_OPCODE_SET_OUTPUT_URB_OFFSETS, dst_reg(message),
231 brw_imm_ud(writemask), indirect_offset);
232 inst->force_writemask_all = true;
233 inst = emit(MOV(byte_offset(dst_reg(retype(message, value.type)), REG_SIZE),
234 value));
235 inst->force_writemask_all = true;
236
237 inst = emit(TCS_OPCODE_URB_WRITE, dst_null_f(), message);
238 inst->offset = base_offset;
239 inst->mlen = 2;
240 inst->base_mrf = -1;
241 }
242
243 void
nir_emit_intrinsic(nir_intrinsic_instr * instr)244 vec4_tcs_visitor::nir_emit_intrinsic(nir_intrinsic_instr *instr)
245 {
246 switch (instr->intrinsic) {
247 case nir_intrinsic_load_invocation_id:
248 emit(MOV(get_nir_dest(instr->dest, BRW_REGISTER_TYPE_UD),
249 invocation_id));
250 break;
251 case nir_intrinsic_load_primitive_id:
252 emit(TCS_OPCODE_GET_PRIMITIVE_ID,
253 get_nir_dest(instr->dest, BRW_REGISTER_TYPE_UD));
254 break;
255 case nir_intrinsic_load_patch_vertices_in:
256 emit(MOV(get_nir_dest(instr->dest, BRW_REGISTER_TYPE_D),
257 brw_imm_d(key->input_vertices)));
258 break;
259 case nir_intrinsic_load_per_vertex_input: {
260 src_reg indirect_offset = get_indirect_offset(instr);
261 unsigned imm_offset = instr->const_index[0];
262
263 nir_const_value *vertex_const = nir_src_as_const_value(instr->src[0]);
264 src_reg vertex_index =
265 vertex_const ? src_reg(brw_imm_ud(vertex_const->u32[0]))
266 : get_nir_src(instr->src[0], BRW_REGISTER_TYPE_UD, 1);
267
268 unsigned first_component = nir_intrinsic_component(instr);
269 if (nir_dest_bit_size(instr->dest) == 64) {
270 /* We need to emit up to two 32-bit URB reads, then shuffle
271 * the result into a temporary, then move to the destination
272 * honoring the writemask
273 *
274 * We don't need to divide first_component by 2 because
275 * emit_input_urb_read takes a 32-bit type.
276 */
277 dst_reg tmp = dst_reg(this, glsl_type::dvec4_type);
278 dst_reg tmp_d = retype(tmp, BRW_REGISTER_TYPE_D);
279 emit_input_urb_read(tmp_d, vertex_index, imm_offset,
280 first_component, indirect_offset);
281 if (instr->num_components > 2) {
282 emit_input_urb_read(byte_offset(tmp_d, REG_SIZE), vertex_index,
283 imm_offset + 1, 0, indirect_offset);
284 }
285
286 src_reg tmp_src = retype(src_reg(tmp_d), BRW_REGISTER_TYPE_DF);
287 dst_reg shuffled = dst_reg(this, glsl_type::dvec4_type);
288 shuffle_64bit_data(shuffled, tmp_src, false);
289
290 dst_reg dst = get_nir_dest(instr->dest, BRW_REGISTER_TYPE_DF);
291 dst.writemask = brw_writemask_for_size(instr->num_components);
292 emit(MOV(dst, src_reg(shuffled)));
293 } else {
294 dst_reg dst = get_nir_dest(instr->dest, BRW_REGISTER_TYPE_D);
295 dst.writemask = brw_writemask_for_size(instr->num_components);
296 emit_input_urb_read(dst, vertex_index, imm_offset,
297 first_component, indirect_offset);
298 }
299 break;
300 }
301 case nir_intrinsic_load_input:
302 unreachable("nir_lower_io should use load_per_vertex_input intrinsics");
303 break;
304 case nir_intrinsic_load_output:
305 case nir_intrinsic_load_per_vertex_output: {
306 src_reg indirect_offset = get_indirect_offset(instr);
307 unsigned imm_offset = instr->const_index[0];
308
309 dst_reg dst = get_nir_dest(instr->dest, BRW_REGISTER_TYPE_D);
310 dst.writemask = brw_writemask_for_size(instr->num_components);
311
312 emit_output_urb_read(dst, imm_offset, nir_intrinsic_component(instr),
313 indirect_offset);
314 break;
315 }
316 case nir_intrinsic_store_output:
317 case nir_intrinsic_store_per_vertex_output: {
318 src_reg value = get_nir_src(instr->src[0]);
319 unsigned mask = instr->const_index[1];
320 unsigned swiz = BRW_SWIZZLE_XYZW;
321
322 src_reg indirect_offset = get_indirect_offset(instr);
323 unsigned imm_offset = instr->const_index[0];
324
325 unsigned first_component = nir_intrinsic_component(instr);
326 if (first_component) {
327 if (nir_src_bit_size(instr->src[0]) == 64)
328 first_component /= 2;
329 assert(swiz == BRW_SWIZZLE_XYZW);
330 swiz = BRW_SWZ_COMP_OUTPUT(first_component);
331 mask = mask << first_component;
332 }
333
334 if (nir_src_bit_size(instr->src[0]) == 64) {
335 /* For 64-bit data we need to shuffle the data before we write and
336 * emit two messages. Also, since each channel is twice as large we
337 * need to fix the writemask in each 32-bit message to account for it.
338 */
339 value = swizzle(retype(value, BRW_REGISTER_TYPE_DF), swiz);
340 dst_reg shuffled = dst_reg(this, glsl_type::dvec4_type);
341 shuffle_64bit_data(shuffled, value, true);
342 src_reg shuffled_float = src_reg(retype(shuffled, BRW_REGISTER_TYPE_F));
343
344 for (int n = 0; n < 2; n++) {
345 unsigned fixed_mask = 0;
346 if (mask & WRITEMASK_X)
347 fixed_mask |= WRITEMASK_XY;
348 if (mask & WRITEMASK_Y)
349 fixed_mask |= WRITEMASK_ZW;
350 emit_urb_write(shuffled_float, fixed_mask,
351 imm_offset, indirect_offset);
352
353 shuffled_float = byte_offset(shuffled_float, REG_SIZE);
354 mask >>= 2;
355 imm_offset++;
356 }
357 } else {
358 emit_urb_write(swizzle(value, swiz), mask,
359 imm_offset, indirect_offset);
360 }
361 break;
362 }
363
364 case nir_intrinsic_barrier: {
365 dst_reg header = dst_reg(this, glsl_type::uvec4_type);
366 emit(TCS_OPCODE_CREATE_BARRIER_HEADER, header);
367 emit(SHADER_OPCODE_BARRIER, dst_null_ud(), src_reg(header));
368 break;
369 }
370
371 default:
372 vec4_visitor::nir_emit_intrinsic(instr);
373 }
374 }
375
376
377 extern "C" const unsigned *
brw_compile_tcs(const struct brw_compiler * compiler,void * log_data,void * mem_ctx,const struct brw_tcs_prog_key * key,struct brw_tcs_prog_data * prog_data,const nir_shader * src_shader,int shader_time_index,char ** error_str)378 brw_compile_tcs(const struct brw_compiler *compiler,
379 void *log_data,
380 void *mem_ctx,
381 const struct brw_tcs_prog_key *key,
382 struct brw_tcs_prog_data *prog_data,
383 const nir_shader *src_shader,
384 int shader_time_index,
385 char **error_str)
386 {
387 const struct gen_device_info *devinfo = compiler->devinfo;
388 struct brw_vue_prog_data *vue_prog_data = &prog_data->base;
389 const bool is_scalar = compiler->scalar_stage[MESA_SHADER_TESS_CTRL];
390 const unsigned *assembly;
391
392 nir_shader *nir = nir_shader_clone(mem_ctx, src_shader);
393 nir->info.outputs_written = key->outputs_written;
394 nir->info.patch_outputs_written = key->patch_outputs_written;
395
396 struct brw_vue_map input_vue_map;
397 brw_compute_vue_map(devinfo, &input_vue_map, nir->info.inputs_read,
398 nir->info.separate_shader);
399 brw_compute_tess_vue_map(&vue_prog_data->vue_map,
400 nir->info.outputs_written,
401 nir->info.patch_outputs_written);
402
403 nir = brw_nir_apply_sampler_key(nir, compiler, &key->tex, is_scalar);
404 brw_nir_lower_vue_inputs(nir, &input_vue_map);
405 brw_nir_lower_tcs_outputs(nir, &vue_prog_data->vue_map,
406 key->tes_primitive_mode);
407 if (key->quads_workaround)
408 brw_nir_apply_tcs_quads_workaround(nir);
409
410 nir = brw_postprocess_nir(nir, compiler, is_scalar);
411
412 if (is_scalar)
413 prog_data->instances = DIV_ROUND_UP(nir->info.tess.tcs_vertices_out, 8);
414 else
415 prog_data->instances = DIV_ROUND_UP(nir->info.tess.tcs_vertices_out, 2);
416
417 /* Compute URB entry size. The maximum allowed URB entry size is 32k.
418 * That divides up as follows:
419 *
420 * 32 bytes for the patch header (tessellation factors)
421 * 480 bytes for per-patch varyings (a varying component is 4 bytes and
422 * gl_MaxTessPatchComponents = 120)
423 * 16384 bytes for per-vertex varyings (a varying component is 4 bytes,
424 * gl_MaxPatchVertices = 32 and
425 * gl_MaxTessControlOutputComponents = 128)
426 *
427 * 15808 bytes left for varying packing overhead
428 */
429 const int num_per_patch_slots = vue_prog_data->vue_map.num_per_patch_slots;
430 const int num_per_vertex_slots = vue_prog_data->vue_map.num_per_vertex_slots;
431 unsigned output_size_bytes = 0;
432 /* Note that the patch header is counted in num_per_patch_slots. */
433 output_size_bytes += num_per_patch_slots * 16;
434 output_size_bytes += nir->info.tess.tcs_vertices_out *
435 num_per_vertex_slots * 16;
436
437 assert(output_size_bytes >= 1);
438 if (output_size_bytes > GEN7_MAX_HS_URB_ENTRY_SIZE_BYTES)
439 return NULL;
440
441 /* URB entry sizes are stored as a multiple of 64 bytes. */
442 vue_prog_data->urb_entry_size = ALIGN(output_size_bytes, 64) / 64;
443
444 /* On Cannonlake software shall not program an allocation size that
445 * specifies a size that is a multiple of 3 64B (512-bit) cachelines.
446 */
447 if (devinfo->gen == 10 &&
448 vue_prog_data->urb_entry_size % 3 == 0)
449 vue_prog_data->urb_entry_size++;
450
451 /* HS does not use the usual payload pushing from URB to GRFs,
452 * because we don't have enough registers for a full-size payload, and
453 * the hardware is broken on Haswell anyway.
454 */
455 vue_prog_data->urb_read_length = 0;
456
457 if (unlikely(INTEL_DEBUG & DEBUG_TCS)) {
458 fprintf(stderr, "TCS Input ");
459 brw_print_vue_map(stderr, &input_vue_map);
460 fprintf(stderr, "TCS Output ");
461 brw_print_vue_map(stderr, &vue_prog_data->vue_map);
462 }
463
464 if (is_scalar) {
465 fs_visitor v(compiler, log_data, mem_ctx, (void *) key,
466 &prog_data->base.base, NULL, nir, 8,
467 shader_time_index, &input_vue_map);
468 if (!v.run_tcs_single_patch()) {
469 if (error_str)
470 *error_str = ralloc_strdup(mem_ctx, v.fail_msg);
471 return NULL;
472 }
473
474 prog_data->base.base.dispatch_grf_start_reg = v.payload.num_regs;
475 prog_data->base.dispatch_mode = DISPATCH_MODE_SIMD8;
476
477 fs_generator g(compiler, log_data, mem_ctx, (void *) key,
478 &prog_data->base.base, v.promoted_constants, false,
479 MESA_SHADER_TESS_CTRL);
480 if (unlikely(INTEL_DEBUG & DEBUG_TCS)) {
481 g.enable_debug(ralloc_asprintf(mem_ctx,
482 "%s tessellation control shader %s",
483 nir->info.label ? nir->info.label
484 : "unnamed",
485 nir->info.name));
486 }
487
488 g.generate_code(v.cfg, 8);
489
490 assembly = g.get_assembly(&prog_data->base.base.program_size);
491 } else {
492 vec4_tcs_visitor v(compiler, log_data, key, prog_data,
493 nir, mem_ctx, shader_time_index, &input_vue_map);
494 if (!v.run()) {
495 if (error_str)
496 *error_str = ralloc_strdup(mem_ctx, v.fail_msg);
497 return NULL;
498 }
499
500 if (unlikely(INTEL_DEBUG & DEBUG_TCS))
501 v.dump_instructions();
502
503
504 assembly = brw_vec4_generate_assembly(compiler, log_data, mem_ctx, nir,
505 &prog_data->base, v.cfg,
506 &prog_data->base.base.program_size);
507 }
508
509 return assembly;
510 }
511
512
513 } /* namespace brw */
514