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radeonsi/gfx10: correct VS PrimitiveID implementation for NGG
[mesa.git] / src / gallium / drivers / radeonsi / gfx10_shader_ngg.c
1 /*
2 * Copyright 2017 Advanced Micro Devices, Inc.
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 * on the rights to use, copy, modify, merge, publish, distribute, sub
8 * license, and/or sell copies of the Software, and to permit persons to whom
9 * the 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 NON-INFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
19 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
20 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
21 * USE OR OTHER DEALINGS IN THE SOFTWARE.
22 */
23
24 #include "si_pipe.h"
25 #include "si_shader_internal.h"
26
27 #include "sid.h"
28
29 #include "util/u_memory.h"
30 #include "util/u_prim.h"
31
32 static LLVMValueRef get_wave_id_in_tg(struct si_shader_context *ctx)
33 {
34 return si_unpack_param(ctx, ctx->merged_wave_info, 24, 4);
35 }
36
37 static LLVMValueRef get_tgsize(struct si_shader_context *ctx)
38 {
39 return si_unpack_param(ctx, ctx->merged_wave_info, 28, 4);
40 }
41
42 static LLVMValueRef get_thread_id_in_tg(struct si_shader_context *ctx)
43 {
44 LLVMBuilderRef builder = ctx->ac.builder;
45 LLVMValueRef tmp;
46 tmp = LLVMBuildMul(builder, get_wave_id_in_tg(ctx),
47 LLVMConstInt(ctx->ac.i32, ctx->ac.wave_size, false), "");
48 return LLVMBuildAdd(builder, tmp, ac_get_thread_id(&ctx->ac), "");
49 }
50
51 static LLVMValueRef ngg_get_vtx_cnt(struct si_shader_context *ctx)
52 {
53 return si_unpack_param(ctx, ctx->gs_tg_info, 12, 9);
54 }
55
56 static LLVMValueRef ngg_get_prim_cnt(struct si_shader_context *ctx)
57 {
58 return si_unpack_param(ctx, ctx->gs_tg_info, 22, 9);
59 }
60
61 static LLVMValueRef ngg_get_ordered_id(struct si_shader_context *ctx)
62 {
63 return si_unpack_param(ctx, ctx->gs_tg_info, 0, 12);
64 }
65
66 static LLVMValueRef ngg_get_query_buf(struct si_shader_context *ctx)
67 {
68 LLVMValueRef buf_ptr = ac_get_arg(&ctx->ac, ctx->rw_buffers);
69
70 return ac_build_load_to_sgpr(&ctx->ac, buf_ptr,
71 LLVMConstInt(ctx->i32, GFX10_GS_QUERY_BUF, false));
72 }
73
74 static LLVMValueRef ngg_get_initial_edgeflag(struct si_shader_context *ctx, unsigned index)
75 {
76 if (ctx->type == PIPE_SHADER_VERTEX) {
77 LLVMValueRef tmp;
78 tmp = LLVMBuildLShr(ctx->ac.builder,
79 ac_get_arg(&ctx->ac, ctx->args.gs_invocation_id),
80 LLVMConstInt(ctx->ac.i32, 8 + index, false), "");
81 return LLVMBuildTrunc(ctx->ac.builder, tmp, ctx->ac.i1, "");
82 }
83 return ctx->i1false;
84 }
85
86 /**
87 * Return the number of vertices as a constant in \p num_vertices,
88 * and return a more precise value as LLVMValueRef from the function.
89 */
90 static LLVMValueRef ngg_get_vertices_per_prim(struct si_shader_context *ctx,
91 unsigned *num_vertices)
92 {
93 const struct si_shader_info *info = &ctx->shader->selector->info;
94
95 if (ctx->type == PIPE_SHADER_VERTEX) {
96 if (info->properties[TGSI_PROPERTY_VS_BLIT_SGPRS_AMD]) {
97 /* Blits always use axis-aligned rectangles with 3 vertices. */
98 *num_vertices = 3;
99 return LLVMConstInt(ctx->i32, 3, 0);
100 } else {
101 /* We always build up all three indices for the prim export
102 * independent of the primitive type. The additional garbage
103 * data shouldn't hurt. This number doesn't matter with
104 * NGG passthrough.
105 */
106 *num_vertices = 3;
107
108 /* Extract OUTPRIM field. */
109 LLVMValueRef num = si_unpack_param(ctx, ctx->vs_state_bits, 2, 2);
110 return LLVMBuildAdd(ctx->ac.builder, num, ctx->i32_1, "");
111 }
112 } else {
113 assert(ctx->type == PIPE_SHADER_TESS_EVAL);
114
115 if (info->properties[TGSI_PROPERTY_TES_POINT_MODE])
116 *num_vertices = 1;
117 else if (info->properties[TGSI_PROPERTY_TES_PRIM_MODE] == PIPE_PRIM_LINES)
118 *num_vertices = 2;
119 else
120 *num_vertices = 3;
121
122 return LLVMConstInt(ctx->i32, *num_vertices, false);
123 }
124 }
125
126 static void build_streamout_vertex(struct si_shader_context *ctx,
127 LLVMValueRef *so_buffer, LLVMValueRef *wg_offset_dw,
128 unsigned stream, LLVMValueRef offset_vtx,
129 LLVMValueRef vertexptr)
130 {
131 struct si_shader_info *info = &ctx->shader->selector->info;
132 struct pipe_stream_output_info *so = &ctx->shader->selector->so;
133 LLVMBuilderRef builder = ctx->ac.builder;
134 LLVMValueRef offset[4] = {};
135 LLVMValueRef tmp;
136
137 for (unsigned buffer = 0; buffer < 4; ++buffer) {
138 if (!wg_offset_dw[buffer])
139 continue;
140
141 tmp = LLVMBuildMul(builder, offset_vtx,
142 LLVMConstInt(ctx->i32, so->stride[buffer], false), "");
143 tmp = LLVMBuildAdd(builder, wg_offset_dw[buffer], tmp, "");
144 offset[buffer] = LLVMBuildShl(builder, tmp, LLVMConstInt(ctx->i32, 2, false), "");
145 }
146
147 for (unsigned i = 0; i < so->num_outputs; ++i) {
148 if (so->output[i].stream != stream)
149 continue;
150
151 unsigned reg = so->output[i].register_index;
152 struct si_shader_output_values out;
153 out.semantic_name = info->output_semantic_name[reg];
154 out.semantic_index = info->output_semantic_index[reg];
155
156 for (unsigned comp = 0; comp < 4; comp++) {
157 tmp = ac_build_gep0(&ctx->ac, vertexptr,
158 LLVMConstInt(ctx->i32, 4 * reg + comp, false));
159 out.values[comp] = LLVMBuildLoad(builder, tmp, "");
160 out.vertex_stream[comp] =
161 (info->output_streams[reg] >> (2 * comp)) & 3;
162 }
163
164 si_emit_streamout_output(ctx, so_buffer, offset, &so->output[i], &out);
165 }
166 }
167
168 struct ngg_streamout {
169 LLVMValueRef num_vertices;
170
171 /* per-thread data */
172 LLVMValueRef prim_enable[4]; /* i1 per stream */
173 LLVMValueRef vertices[3]; /* [N x i32] addrspace(LDS)* */
174
175 /* Output */
176 LLVMValueRef emit[4]; /* per-stream emitted primitives (only valid for used streams) */
177 };
178
179 /**
180 * Build streamout logic.
181 *
182 * Implies a barrier.
183 *
184 * Writes number of emitted primitives to gs_ngg_scratch[4:8].
185 *
186 * Clobbers gs_ngg_scratch[8:].
187 */
188 static void build_streamout(struct si_shader_context *ctx,
189 struct ngg_streamout *nggso)
190 {
191 struct si_shader_info *info = &ctx->shader->selector->info;
192 struct pipe_stream_output_info *so = &ctx->shader->selector->so;
193 LLVMBuilderRef builder = ctx->ac.builder;
194 LLVMValueRef buf_ptr = ac_get_arg(&ctx->ac, ctx->rw_buffers);
195 LLVMValueRef tid = get_thread_id_in_tg(ctx);
196 LLVMValueRef tmp, tmp2;
197 LLVMValueRef i32_2 = LLVMConstInt(ctx->i32, 2, false);
198 LLVMValueRef i32_4 = LLVMConstInt(ctx->i32, 4, false);
199 LLVMValueRef i32_8 = LLVMConstInt(ctx->i32, 8, false);
200 LLVMValueRef so_buffer[4] = {};
201 unsigned max_num_vertices = 1 + (nggso->vertices[1] ? 1 : 0) +
202 (nggso->vertices[2] ? 1 : 0);
203 LLVMValueRef prim_stride_dw[4] = {};
204 LLVMValueRef prim_stride_dw_vgpr = LLVMGetUndef(ctx->i32);
205 int stream_for_buffer[4] = { -1, -1, -1, -1 };
206 unsigned bufmask_for_stream[4] = {};
207 bool isgs = ctx->type == PIPE_SHADER_GEOMETRY;
208 unsigned scratch_emit_base = isgs ? 4 : 0;
209 LLVMValueRef scratch_emit_basev = isgs ? i32_4 : ctx->i32_0;
210 unsigned scratch_offset_base = isgs ? 8 : 4;
211 LLVMValueRef scratch_offset_basev = isgs ? i32_8 : i32_4;
212
213 ac_llvm_add_target_dep_function_attr(ctx->main_fn, "amdgpu-gds-size", 256);
214
215 /* Determine the mapping of streamout buffers to vertex streams. */
216 for (unsigned i = 0; i < so->num_outputs; ++i) {
217 unsigned buf = so->output[i].output_buffer;
218 unsigned stream = so->output[i].stream;
219 assert(stream_for_buffer[buf] < 0 || stream_for_buffer[buf] == stream);
220 stream_for_buffer[buf] = stream;
221 bufmask_for_stream[stream] |= 1 << buf;
222 }
223
224 for (unsigned buffer = 0; buffer < 4; ++buffer) {
225 if (stream_for_buffer[buffer] == -1)
226 continue;
227
228 assert(so->stride[buffer]);
229
230 tmp = LLVMConstInt(ctx->i32, so->stride[buffer], false);
231 prim_stride_dw[buffer] = LLVMBuildMul(builder, tmp, nggso->num_vertices, "");
232 prim_stride_dw_vgpr = ac_build_writelane(
233 &ctx->ac, prim_stride_dw_vgpr, prim_stride_dw[buffer],
234 LLVMConstInt(ctx->i32, buffer, false));
235
236 so_buffer[buffer] = ac_build_load_to_sgpr(
237 &ctx->ac, buf_ptr,
238 LLVMConstInt(ctx->i32, SI_VS_STREAMOUT_BUF0 + buffer, false));
239 }
240
241 tmp = LLVMBuildICmp(builder, LLVMIntEQ, get_wave_id_in_tg(ctx), ctx->i32_0, "");
242 ac_build_ifcc(&ctx->ac, tmp, 5200);
243 {
244 LLVMTypeRef gdsptr = LLVMPointerType(ctx->i32, AC_ADDR_SPACE_GDS);
245 LLVMValueRef gdsbase = LLVMBuildIntToPtr(builder, ctx->i32_0, gdsptr, "");
246
247 /* Advance the streamout offsets in GDS. */
248 LLVMValueRef offsets_vgpr = ac_build_alloca_undef(&ctx->ac, ctx->i32, "");
249 LLVMValueRef generated_by_stream_vgpr = ac_build_alloca_undef(&ctx->ac, ctx->i32, "");
250
251 tmp = LLVMBuildICmp(builder, LLVMIntULT, ac_get_thread_id(&ctx->ac), i32_4, "");
252 ac_build_ifcc(&ctx->ac, tmp, 5210);
253 {
254 if (isgs) {
255 tmp = ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch, tid);
256 tmp = LLVMBuildLoad(builder, tmp, "");
257 } else {
258 tmp = ac_build_writelane(&ctx->ac, ctx->i32_0,
259 ngg_get_prim_cnt(ctx), ctx->i32_0);
260 }
261 LLVMBuildStore(builder, tmp, generated_by_stream_vgpr);
262
263 unsigned swizzle[4];
264 int unused_stream = -1;
265 for (unsigned stream = 0; stream < 4; ++stream) {
266 if (!info->num_stream_output_components[stream]) {
267 unused_stream = stream;
268 break;
269 }
270 }
271 for (unsigned buffer = 0; buffer < 4; ++buffer) {
272 if (stream_for_buffer[buffer] >= 0) {
273 swizzle[buffer] = stream_for_buffer[buffer];
274 } else {
275 assert(unused_stream >= 0);
276 swizzle[buffer] = unused_stream;
277 }
278 }
279
280 tmp = ac_build_quad_swizzle(&ctx->ac, tmp,
281 swizzle[0], swizzle[1], swizzle[2], swizzle[3]);
282 tmp = LLVMBuildMul(builder, tmp, prim_stride_dw_vgpr, "");
283
284 LLVMValueRef args[] = {
285 LLVMBuildIntToPtr(builder, ngg_get_ordered_id(ctx), gdsptr, ""),
286 tmp,
287 ctx->i32_0, // ordering
288 ctx->i32_0, // scope
289 ctx->ac.i1false, // isVolatile
290 LLVMConstInt(ctx->i32, 4 << 24, false), // OA index
291 ctx->ac.i1true, // wave release
292 ctx->ac.i1true, // wave done
293 };
294 tmp = ac_build_intrinsic(&ctx->ac, "llvm.amdgcn.ds.ordered.add",
295 ctx->i32, args, ARRAY_SIZE(args), 0);
296
297 /* Keep offsets in a VGPR for quick retrieval via readlane by
298 * the first wave for bounds checking, and also store in LDS
299 * for retrieval by all waves later. */
300 LLVMBuildStore(builder, tmp, offsets_vgpr);
301
302 tmp2 = LLVMBuildAdd(builder, ac_get_thread_id(&ctx->ac),
303 scratch_offset_basev, "");
304 tmp2 = ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch, tmp2);
305 LLVMBuildStore(builder, tmp, tmp2);
306 }
307 ac_build_endif(&ctx->ac, 5210);
308
309 /* Determine the max emit per buffer. This is done via the SALU, in part
310 * because LLVM can't generate divide-by-multiply if we try to do this
311 * via VALU with one lane per buffer.
312 */
313 LLVMValueRef max_emit[4] = {};
314 for (unsigned buffer = 0; buffer < 4; ++buffer) {
315 if (stream_for_buffer[buffer] == -1)
316 continue;
317
318 LLVMValueRef bufsize_dw =
319 LLVMBuildLShr(builder,
320 LLVMBuildExtractElement(builder, so_buffer[buffer], i32_2, ""),
321 i32_2, "");
322
323 tmp = LLVMBuildLoad(builder, offsets_vgpr, "");
324 LLVMValueRef offset_dw =
325 ac_build_readlane(&ctx->ac, tmp,
326 LLVMConstInt(ctx->i32, buffer, false));
327
328 tmp = LLVMBuildSub(builder, bufsize_dw, offset_dw, "");
329 tmp = LLVMBuildUDiv(builder, tmp, prim_stride_dw[buffer], "");
330
331 tmp2 = LLVMBuildICmp(builder, LLVMIntULT, bufsize_dw, offset_dw, "");
332 max_emit[buffer] = LLVMBuildSelect(builder, tmp2, ctx->i32_0, tmp, "");
333 }
334
335 /* Determine the number of emitted primitives per stream and fixup the
336 * GDS counter if necessary.
337 *
338 * This is complicated by the fact that a single stream can emit to
339 * multiple buffers (but luckily not vice versa).
340 */
341 LLVMValueRef emit_vgpr = ctx->i32_0;
342
343 for (unsigned stream = 0; stream < 4; ++stream) {
344 if (!info->num_stream_output_components[stream])
345 continue;
346
347 tmp = LLVMBuildLoad(builder, generated_by_stream_vgpr, "");
348 LLVMValueRef generated =
349 ac_build_readlane(&ctx->ac, tmp,
350 LLVMConstInt(ctx->i32, stream, false));
351
352 LLVMValueRef emit = generated;
353 for (unsigned buffer = 0; buffer < 4; ++buffer) {
354 if (stream_for_buffer[buffer] == stream)
355 emit = ac_build_umin(&ctx->ac, emit, max_emit[buffer]);
356 }
357
358 emit_vgpr = ac_build_writelane(&ctx->ac, emit_vgpr, emit,
359 LLVMConstInt(ctx->i32, stream, false));
360
361 /* Fixup the offset using a plain GDS atomic if we overflowed. */
362 tmp = LLVMBuildICmp(builder, LLVMIntULT, emit, generated, "");
363 ac_build_ifcc(&ctx->ac, tmp, 5221); /* scalar branch */
364 tmp = LLVMBuildLShr(builder,
365 LLVMConstInt(ctx->i32, bufmask_for_stream[stream], false),
366 ac_get_thread_id(&ctx->ac), "");
367 tmp = LLVMBuildTrunc(builder, tmp, ctx->i1, "");
368 ac_build_ifcc(&ctx->ac, tmp, 5222);
369 {
370 tmp = LLVMBuildSub(builder, generated, emit, "");
371 tmp = LLVMBuildMul(builder, tmp, prim_stride_dw_vgpr, "");
372 tmp2 = LLVMBuildGEP(builder, gdsbase, &tid, 1, "");
373 LLVMBuildAtomicRMW(builder, LLVMAtomicRMWBinOpSub, tmp2, tmp,
374 LLVMAtomicOrderingMonotonic, false);
375 }
376 ac_build_endif(&ctx->ac, 5222);
377 ac_build_endif(&ctx->ac, 5221);
378 }
379
380 tmp = LLVMBuildICmp(builder, LLVMIntULT, ac_get_thread_id(&ctx->ac), i32_4, "");
381 ac_build_ifcc(&ctx->ac, tmp, 5225);
382 {
383 tmp = LLVMBuildAdd(builder, ac_get_thread_id(&ctx->ac),
384 scratch_emit_basev, "");
385 tmp = ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch, tmp);
386 LLVMBuildStore(builder, emit_vgpr, tmp);
387 }
388 ac_build_endif(&ctx->ac, 5225);
389 }
390 ac_build_endif(&ctx->ac, 5200);
391
392 /* Determine the workgroup-relative per-thread / primitive offset into
393 * the streamout buffers */
394 struct ac_wg_scan primemit_scan[4] = {};
395
396 if (isgs) {
397 for (unsigned stream = 0; stream < 4; ++stream) {
398 if (!info->num_stream_output_components[stream])
399 continue;
400
401 primemit_scan[stream].enable_exclusive = true;
402 primemit_scan[stream].op = nir_op_iadd;
403 primemit_scan[stream].src = nggso->prim_enable[stream];
404 primemit_scan[stream].scratch =
405 ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch,
406 LLVMConstInt(ctx->i32, 12 + 8 * stream, false));
407 primemit_scan[stream].waveidx = get_wave_id_in_tg(ctx);
408 primemit_scan[stream].numwaves = get_tgsize(ctx);
409 primemit_scan[stream].maxwaves = 8;
410 ac_build_wg_scan_top(&ctx->ac, &primemit_scan[stream]);
411 }
412 }
413
414 ac_build_s_barrier(&ctx->ac);
415
416 /* Fetch the per-buffer offsets and per-stream emit counts in all waves. */
417 LLVMValueRef wgoffset_dw[4] = {};
418
419 {
420 LLVMValueRef scratch_vgpr;
421
422 tmp = ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch, ac_get_thread_id(&ctx->ac));
423 scratch_vgpr = LLVMBuildLoad(builder, tmp, "");
424
425 for (unsigned buffer = 0; buffer < 4; ++buffer) {
426 if (stream_for_buffer[buffer] >= 0) {
427 wgoffset_dw[buffer] = ac_build_readlane(
428 &ctx->ac, scratch_vgpr,
429 LLVMConstInt(ctx->i32, scratch_offset_base + buffer, false));
430 }
431 }
432
433 for (unsigned stream = 0; stream < 4; ++stream) {
434 if (info->num_stream_output_components[stream]) {
435 nggso->emit[stream] = ac_build_readlane(
436 &ctx->ac, scratch_vgpr,
437 LLVMConstInt(ctx->i32, scratch_emit_base + stream, false));
438 }
439 }
440 }
441
442 /* Write out primitive data */
443 for (unsigned stream = 0; stream < 4; ++stream) {
444 if (!info->num_stream_output_components[stream])
445 continue;
446
447 if (isgs) {
448 ac_build_wg_scan_bottom(&ctx->ac, &primemit_scan[stream]);
449 } else {
450 primemit_scan[stream].result_exclusive = tid;
451 }
452
453 tmp = LLVMBuildICmp(builder, LLVMIntULT,
454 primemit_scan[stream].result_exclusive,
455 nggso->emit[stream], "");
456 tmp = LLVMBuildAnd(builder, tmp, nggso->prim_enable[stream], "");
457 ac_build_ifcc(&ctx->ac, tmp, 5240);
458 {
459 LLVMValueRef offset_vtx =
460 LLVMBuildMul(builder, primemit_scan[stream].result_exclusive,
461 nggso->num_vertices, "");
462
463 for (unsigned i = 0; i < max_num_vertices; ++i) {
464 tmp = LLVMBuildICmp(builder, LLVMIntULT,
465 LLVMConstInt(ctx->i32, i, false),
466 nggso->num_vertices, "");
467 ac_build_ifcc(&ctx->ac, tmp, 5241);
468 build_streamout_vertex(ctx, so_buffer, wgoffset_dw,
469 stream, offset_vtx, nggso->vertices[i]);
470 ac_build_endif(&ctx->ac, 5241);
471 offset_vtx = LLVMBuildAdd(builder, offset_vtx, ctx->i32_1, "");
472 }
473 }
474 ac_build_endif(&ctx->ac, 5240);
475 }
476 }
477
478 static unsigned ngg_nogs_vertex_size(struct si_shader *shader)
479 {
480 unsigned lds_vertex_size = 0;
481
482 /* The edgeflag is always stored in the last element that's also
483 * used for padding to reduce LDS bank conflicts. */
484 if (shader->selector->so.num_outputs)
485 lds_vertex_size = 4 * shader->selector->info.num_outputs + 1;
486 if (shader->selector->info.writes_edgeflag)
487 lds_vertex_size = MAX2(lds_vertex_size, 1);
488
489 /* LDS size for passing data from GS to ES.
490 * GS stores Primitive IDs into LDS at the address corresponding
491 * to the ES thread of the provoking vertex. All ES threads
492 * load and export PrimitiveID for their thread.
493 */
494 if (shader->selector->type == PIPE_SHADER_VERTEX &&
495 shader->key.mono.u.vs_export_prim_id)
496 lds_vertex_size = MAX2(lds_vertex_size, 1);
497
498 return lds_vertex_size;
499 }
500
501 /**
502 * Returns an `[N x i32] addrspace(LDS)*` pointing at contiguous LDS storage
503 * for the vertex outputs.
504 */
505 static LLVMValueRef ngg_nogs_vertex_ptr(struct si_shader_context *ctx,
506 LLVMValueRef vtxid)
507 {
508 /* The extra dword is used to avoid LDS bank conflicts. */
509 unsigned vertex_size = ngg_nogs_vertex_size(ctx->shader);
510 LLVMTypeRef ai32 = LLVMArrayType(ctx->i32, vertex_size);
511 LLVMTypeRef pai32 = LLVMPointerType(ai32, AC_ADDR_SPACE_LDS);
512 LLVMValueRef tmp = LLVMBuildBitCast(ctx->ac.builder, ctx->esgs_ring, pai32, "");
513 return LLVMBuildGEP(ctx->ac.builder, tmp, &vtxid, 1, "");
514 }
515
516 /**
517 * Emit the epilogue of an API VS or TES shader compiled as ESGS shader.
518 */
519 void gfx10_emit_ngg_epilogue(struct ac_shader_abi *abi,
520 unsigned max_outputs,
521 LLVMValueRef *addrs)
522 {
523 struct si_shader_context *ctx = si_shader_context_from_abi(abi);
524 struct si_shader_selector *sel = ctx->shader->selector;
525 struct si_shader_info *info = &sel->info;
526 struct si_shader_output_values outputs[PIPE_MAX_SHADER_OUTPUTS];
527 LLVMBuilderRef builder = ctx->ac.builder;
528 LLVMValueRef tmp, tmp2;
529
530 assert(!ctx->shader->is_gs_copy_shader);
531 assert(info->num_outputs <= max_outputs);
532
533 LLVMValueRef vertex_ptr = NULL;
534
535 if (sel->so.num_outputs || sel->info.writes_edgeflag)
536 vertex_ptr = ngg_nogs_vertex_ptr(ctx, get_thread_id_in_tg(ctx));
537
538 for (unsigned i = 0; i < info->num_outputs; i++) {
539 outputs[i].semantic_name = info->output_semantic_name[i];
540 outputs[i].semantic_index = info->output_semantic_index[i];
541
542 for (unsigned j = 0; j < 4; j++) {
543 outputs[i].vertex_stream[j] =
544 (info->output_streams[i] >> (2 * j)) & 3;
545
546 /* TODO: we may store more outputs than streamout needs,
547 * but streamout performance isn't that important.
548 */
549 if (sel->so.num_outputs) {
550 tmp = ac_build_gep0(&ctx->ac, vertex_ptr,
551 LLVMConstInt(ctx->i32, 4 * i + j, false));
552 tmp2 = LLVMBuildLoad(builder, addrs[4 * i + j], "");
553 tmp2 = ac_to_integer(&ctx->ac, tmp2);
554 LLVMBuildStore(builder, tmp2, tmp);
555 }
556 }
557
558 /* Store the edgeflag at the end (if streamout is enabled) */
559 if (info->output_semantic_name[i] == TGSI_SEMANTIC_EDGEFLAG &&
560 sel->info.writes_edgeflag) {
561 LLVMValueRef edgeflag = LLVMBuildLoad(builder, addrs[4 * i], "");
562 /* The output is a float, but the hw expects a 1-bit integer. */
563 edgeflag = LLVMBuildFPToUI(ctx->ac.builder, edgeflag, ctx->i32, "");
564 edgeflag = ac_build_umin(&ctx->ac, edgeflag, ctx->i32_1);
565
566 tmp = LLVMConstInt(ctx->i32, ngg_nogs_vertex_size(ctx->shader) - 1, 0);
567 tmp = ac_build_gep0(&ctx->ac, vertex_ptr, tmp);
568 LLVMBuildStore(builder, edgeflag, tmp);
569 }
570 }
571
572 ac_build_endif(&ctx->ac, ctx->merged_wrap_if_label);
573
574 LLVMValueRef is_gs_thread = si_is_gs_thread(ctx);
575 LLVMValueRef is_es_thread = si_is_es_thread(ctx);
576 LLVMValueRef vtxindex[] = {
577 si_unpack_param(ctx, ctx->gs_vtx01_offset, 0, 16),
578 si_unpack_param(ctx, ctx->gs_vtx01_offset, 16, 16),
579 si_unpack_param(ctx, ctx->gs_vtx23_offset, 0, 16),
580 };
581
582 /* Determine the number of vertices per primitive. */
583 unsigned num_vertices;
584 LLVMValueRef num_vertices_val = ngg_get_vertices_per_prim(ctx, &num_vertices);
585
586 /* Streamout */
587 LLVMValueRef emitted_prims = NULL;
588
589 if (sel->so.num_outputs) {
590 struct ngg_streamout nggso = {};
591
592 nggso.num_vertices = num_vertices_val;
593 nggso.prim_enable[0] = is_gs_thread;
594
595 for (unsigned i = 0; i < num_vertices; ++i)
596 nggso.vertices[i] = ngg_nogs_vertex_ptr(ctx, vtxindex[i]);
597
598 build_streamout(ctx, &nggso);
599 emitted_prims = nggso.emit[0];
600 }
601
602 LLVMValueRef user_edgeflags[3] = {};
603
604 if (sel->info.writes_edgeflag) {
605 /* Streamout already inserted the barrier, so don't insert it again. */
606 if (!sel->so.num_outputs)
607 ac_build_s_barrier(&ctx->ac);
608
609 ac_build_ifcc(&ctx->ac, is_gs_thread, 5400);
610 /* Load edge flags from ES threads and store them into VGPRs in GS threads. */
611 for (unsigned i = 0; i < num_vertices; i++) {
612 tmp = ngg_nogs_vertex_ptr(ctx, vtxindex[i]);
613 tmp2 = LLVMConstInt(ctx->i32, ngg_nogs_vertex_size(ctx->shader) - 1, 0);
614 tmp = ac_build_gep0(&ctx->ac, tmp, tmp2);
615 tmp = LLVMBuildLoad(builder, tmp, "");
616 tmp = LLVMBuildTrunc(builder, tmp, ctx->i1, "");
617
618 user_edgeflags[i] = ac_build_alloca_undef(&ctx->ac, ctx->i1, "");
619 LLVMBuildStore(builder, tmp, user_edgeflags[i]);
620 }
621 ac_build_endif(&ctx->ac, 5400);
622 }
623
624 /* Copy Primitive IDs from GS threads to the LDS address corresponding
625 * to the ES thread of the provoking vertex.
626 */
627 if (ctx->type == PIPE_SHADER_VERTEX &&
628 ctx->shader->key.mono.u.vs_export_prim_id) {
629 /* Streamout and edge flags use LDS. Make it idle, so that we can reuse it. */
630 if (sel->so.num_outputs || sel->info.writes_edgeflag)
631 ac_build_s_barrier(&ctx->ac);
632
633 ac_build_ifcc(&ctx->ac, is_gs_thread, 5400);
634 /* Extract the PROVOKING_VTX_INDEX field. */
635 LLVMValueRef provoking_vtx_in_prim =
636 si_unpack_param(ctx, ctx->vs_state_bits, 4, 2);
637
638 /* provoking_vtx_index = vtxindex[provoking_vtx_in_prim]; */
639 LLVMValueRef indices = ac_build_gather_values(&ctx->ac, vtxindex, 3);
640 LLVMValueRef provoking_vtx_index =
641 LLVMBuildExtractElement(builder, indices, provoking_vtx_in_prim, "");
642 LLVMValueRef vertex_ptr = ngg_nogs_vertex_ptr(ctx, provoking_vtx_index);
643
644 LLVMBuildStore(builder, ac_get_arg(&ctx->ac, ctx->args.gs_prim_id),
645 ac_build_gep0(&ctx->ac, vertex_ptr, ctx->i32_0));
646 ac_build_endif(&ctx->ac, 5400);
647 }
648
649 ac_build_sendmsg_gs_alloc_req(&ctx->ac, get_wave_id_in_tg(ctx),
650 ngg_get_vtx_cnt(ctx), ngg_get_prim_cnt(ctx));
651
652 /* Update query buffer */
653 if (ctx->screen->use_ngg_streamout &&
654 !info->properties[TGSI_PROPERTY_VS_BLIT_SGPRS_AMD]) {
655 tmp = si_unpack_param(ctx, ctx->vs_state_bits, 6, 1);
656 tmp = LLVMBuildTrunc(builder, tmp, ctx->i1, "");
657 ac_build_ifcc(&ctx->ac, tmp, 5029); /* if (STREAMOUT_QUERY_ENABLED) */
658 tmp = LLVMBuildICmp(builder, LLVMIntEQ, get_wave_id_in_tg(ctx), ctx->ac.i32_0, "");
659 ac_build_ifcc(&ctx->ac, tmp, 5030);
660 tmp = LLVMBuildICmp(builder, LLVMIntULE, ac_get_thread_id(&ctx->ac),
661 sel->so.num_outputs ? ctx->ac.i32_1 : ctx->ac.i32_0, "");
662 ac_build_ifcc(&ctx->ac, tmp, 5031);
663 {
664 LLVMValueRef args[] = {
665 ngg_get_prim_cnt(ctx),
666 ngg_get_query_buf(ctx),
667 LLVMConstInt(ctx->i32, 16, false), /* offset of stream[0].generated_primitives */
668 ctx->i32_0, /* soffset */
669 ctx->i32_0, /* cachepolicy */
670 };
671
672 if (sel->so.num_outputs) {
673 args[0] = ac_build_writelane(&ctx->ac, args[0], emitted_prims, ctx->i32_1);
674 args[2] = ac_build_writelane(&ctx->ac, args[2],
675 LLVMConstInt(ctx->i32, 24, false), ctx->i32_1);
676 }
677
678 /* TODO: should this be 64-bit atomics? */
679 ac_build_intrinsic(&ctx->ac, "llvm.amdgcn.raw.buffer.atomic.add.i32",
680 ctx->i32, args, 5, 0);
681 }
682 ac_build_endif(&ctx->ac, 5031);
683 ac_build_endif(&ctx->ac, 5030);
684 ac_build_endif(&ctx->ac, 5029);
685 }
686
687 /* Build the primitive export. */
688 ac_build_ifcc(&ctx->ac, is_gs_thread, 6001);
689 {
690 struct ac_ngg_prim prim = {};
691
692 if (gfx10_is_ngg_passthrough(ctx->shader)) {
693 prim.passthrough = ac_get_arg(&ctx->ac, ctx->gs_vtx01_offset);
694 } else {
695 prim.num_vertices = num_vertices;
696 prim.isnull = ctx->ac.i1false;
697 memcpy(prim.index, vtxindex, sizeof(vtxindex[0]) * 3);
698
699 for (unsigned i = 0; i < num_vertices; ++i) {
700 prim.edgeflag[i] = ngg_get_initial_edgeflag(ctx, i);
701
702 if (sel->info.writes_edgeflag) {
703 tmp2 = LLVMBuildLoad(builder, user_edgeflags[i], "");
704 prim.edgeflag[i] = LLVMBuildAnd(builder, prim.edgeflag[i],
705 tmp2, "");
706 }
707 }
708 }
709
710 ac_build_export_prim(&ctx->ac, &prim);
711 }
712 ac_build_endif(&ctx->ac, 6001);
713
714 /* Export per-vertex data (positions and parameters). */
715 ac_build_ifcc(&ctx->ac, is_es_thread, 6002);
716 {
717 unsigned i;
718
719 /* Unconditionally (re-)load the values for proper SSA form. */
720 for (i = 0; i < info->num_outputs; i++) {
721 for (unsigned j = 0; j < 4; j++) {
722 outputs[i].values[j] =
723 LLVMBuildLoad(builder,
724 addrs[4 * i + j],
725 "");
726 }
727 }
728
729 if (ctx->shader->key.mono.u.vs_export_prim_id) {
730 outputs[i].semantic_name = TGSI_SEMANTIC_PRIMID;
731 outputs[i].semantic_index = 0;
732
733 if (ctx->type == PIPE_SHADER_VERTEX) {
734 /* Wait for GS stores to finish. */
735 ac_build_s_barrier(&ctx->ac);
736
737 tmp = ngg_nogs_vertex_ptr(ctx, get_thread_id_in_tg(ctx));
738 tmp = ac_build_gep0(&ctx->ac, tmp, ctx->i32_0);
739 outputs[i].values[0] = LLVMBuildLoad(builder, tmp, "");
740 } else {
741 assert(ctx->type == PIPE_SHADER_TESS_EVAL);
742 outputs[i].values[0] = si_get_primitive_id(ctx, 0);
743 }
744
745 outputs[i].values[0] = ac_to_float(&ctx->ac, outputs[i].values[0]);
746 for (unsigned j = 1; j < 4; j++)
747 outputs[i].values[j] = LLVMGetUndef(ctx->f32);
748
749 memset(outputs[i].vertex_stream, 0,
750 sizeof(outputs[i].vertex_stream));
751 i++;
752 }
753
754 si_llvm_export_vs(ctx, outputs, i);
755 }
756 ac_build_endif(&ctx->ac, 6002);
757 }
758
759 static LLVMValueRef
760 ngg_gs_get_vertex_storage(struct si_shader_context *ctx)
761 {
762 const struct si_shader_selector *sel = ctx->shader->selector;
763 const struct si_shader_info *info = &sel->info;
764
765 LLVMTypeRef elements[2] = {
766 LLVMArrayType(ctx->ac.i32, 4 * info->num_outputs),
767 LLVMArrayType(ctx->ac.i8, 4),
768 };
769 LLVMTypeRef type = LLVMStructTypeInContext(ctx->ac.context, elements, 2, false);
770 type = LLVMPointerType(LLVMArrayType(type, 0), AC_ADDR_SPACE_LDS);
771 return LLVMBuildBitCast(ctx->ac.builder, ctx->gs_ngg_emit, type, "");
772 }
773
774 /**
775 * Return a pointer to the LDS storage reserved for the N'th vertex, where N
776 * is in emit order; that is:
777 * - during the epilogue, N is the threadidx (relative to the entire threadgroup)
778 * - during vertex emit, i.e. while the API GS shader invocation is running,
779 * N = threadidx * gs_max_out_vertices + emitidx
780 *
781 * Goals of the LDS memory layout:
782 * 1. Eliminate bank conflicts on write for geometry shaders that have all emits
783 * in uniform control flow
784 * 2. Eliminate bank conflicts on read for export if, additionally, there is no
785 * culling
786 * 3. Agnostic to the number of waves (since we don't know it before compiling)
787 * 4. Allow coalescing of LDS instructions (ds_write_b128 etc.)
788 * 5. Avoid wasting memory.
789 *
790 * We use an AoS layout due to point 4 (this also helps point 3). In an AoS
791 * layout, elimination of bank conflicts requires that each vertex occupy an
792 * odd number of dwords. We use the additional dword to store the output stream
793 * index as well as a flag to indicate whether this vertex ends a primitive
794 * for rasterization.
795 *
796 * Swizzling is required to satisfy points 1 and 2 simultaneously.
797 *
798 * Vertices are stored in export order (gsthread * gs_max_out_vertices + emitidx).
799 * Indices are swizzled in groups of 32, which ensures point 1 without
800 * disturbing point 2.
801 *
802 * \return an LDS pointer to type {[N x i32], [4 x i8]}
803 */
804 static LLVMValueRef
805 ngg_gs_vertex_ptr(struct si_shader_context *ctx, LLVMValueRef vertexidx)
806 {
807 struct si_shader_selector *sel = ctx->shader->selector;
808 LLVMBuilderRef builder = ctx->ac.builder;
809 LLVMValueRef storage = ngg_gs_get_vertex_storage(ctx);
810
811 /* gs_max_out_vertices = 2^(write_stride_2exp) * some odd number */
812 unsigned write_stride_2exp = ffs(sel->gs_max_out_vertices) - 1;
813 if (write_stride_2exp) {
814 LLVMValueRef row =
815 LLVMBuildLShr(builder, vertexidx,
816 LLVMConstInt(ctx->ac.i32, 5, false), "");
817 LLVMValueRef swizzle =
818 LLVMBuildAnd(builder, row,
819 LLVMConstInt(ctx->ac.i32, (1u << write_stride_2exp) - 1,
820 false), "");
821 vertexidx = LLVMBuildXor(builder, vertexidx, swizzle, "");
822 }
823
824 return ac_build_gep0(&ctx->ac, storage, vertexidx);
825 }
826
827 static LLVMValueRef
828 ngg_gs_emit_vertex_ptr(struct si_shader_context *ctx, LLVMValueRef gsthread,
829 LLVMValueRef emitidx)
830 {
831 struct si_shader_selector *sel = ctx->shader->selector;
832 LLVMBuilderRef builder = ctx->ac.builder;
833 LLVMValueRef tmp;
834
835 tmp = LLVMConstInt(ctx->ac.i32, sel->gs_max_out_vertices, false);
836 tmp = LLVMBuildMul(builder, tmp, gsthread, "");
837 const LLVMValueRef vertexidx = LLVMBuildAdd(builder, tmp, emitidx, "");
838 return ngg_gs_vertex_ptr(ctx, vertexidx);
839 }
840
841 static LLVMValueRef
842 ngg_gs_get_emit_output_ptr(struct si_shader_context *ctx, LLVMValueRef vertexptr,
843 unsigned out_idx)
844 {
845 LLVMValueRef gep_idx[3] = {
846 ctx->ac.i32_0, /* implied C-style array */
847 ctx->ac.i32_0, /* first struct entry */
848 LLVMConstInt(ctx->ac.i32, out_idx, false),
849 };
850 return LLVMBuildGEP(ctx->ac.builder, vertexptr, gep_idx, 3, "");
851 }
852
853 static LLVMValueRef
854 ngg_gs_get_emit_primflag_ptr(struct si_shader_context *ctx, LLVMValueRef vertexptr,
855 unsigned stream)
856 {
857 LLVMValueRef gep_idx[3] = {
858 ctx->ac.i32_0, /* implied C-style array */
859 ctx->ac.i32_1, /* second struct entry */
860 LLVMConstInt(ctx->ac.i32, stream, false),
861 };
862 return LLVMBuildGEP(ctx->ac.builder, vertexptr, gep_idx, 3, "");
863 }
864
865 void gfx10_ngg_gs_emit_vertex(struct si_shader_context *ctx,
866 unsigned stream,
867 LLVMValueRef *addrs)
868 {
869 const struct si_shader_selector *sel = ctx->shader->selector;
870 const struct si_shader_info *info = &sel->info;
871 LLVMBuilderRef builder = ctx->ac.builder;
872 LLVMValueRef tmp;
873 const LLVMValueRef vertexidx =
874 LLVMBuildLoad(builder, ctx->gs_next_vertex[stream], "");
875
876 /* If this thread has already emitted the declared maximum number of
877 * vertices, skip the write: excessive vertex emissions are not
878 * supposed to have any effect.
879 */
880 const LLVMValueRef can_emit =
881 LLVMBuildICmp(builder, LLVMIntULT, vertexidx,
882 LLVMConstInt(ctx->i32, sel->gs_max_out_vertices, false), "");
883
884 tmp = LLVMBuildAdd(builder, vertexidx, ctx->ac.i32_1, "");
885 tmp = LLVMBuildSelect(builder, can_emit, tmp, vertexidx, "");
886 LLVMBuildStore(builder, tmp, ctx->gs_next_vertex[stream]);
887
888 ac_build_ifcc(&ctx->ac, can_emit, 9001);
889
890 const LLVMValueRef vertexptr =
891 ngg_gs_emit_vertex_ptr(ctx, get_thread_id_in_tg(ctx), vertexidx);
892 unsigned out_idx = 0;
893 for (unsigned i = 0; i < info->num_outputs; i++) {
894 for (unsigned chan = 0; chan < 4; chan++, out_idx++) {
895 if (!(info->output_usagemask[i] & (1 << chan)) ||
896 ((info->output_streams[i] >> (2 * chan)) & 3) != stream)
897 continue;
898
899 LLVMValueRef out_val = LLVMBuildLoad(builder, addrs[4 * i + chan], "");
900 out_val = ac_to_integer(&ctx->ac, out_val);
901 LLVMBuildStore(builder, out_val,
902 ngg_gs_get_emit_output_ptr(ctx, vertexptr, out_idx));
903 }
904 }
905 assert(out_idx * 4 == sel->gsvs_vertex_size);
906
907 /* Determine and store whether this vertex completed a primitive. */
908 const LLVMValueRef curverts = LLVMBuildLoad(builder, ctx->gs_curprim_verts[stream], "");
909
910 tmp = LLVMConstInt(ctx->ac.i32, u_vertices_per_prim(sel->gs_output_prim) - 1, false);
911 const LLVMValueRef iscompleteprim =
912 LLVMBuildICmp(builder, LLVMIntUGE, curverts, tmp, "");
913
914 /* Since the geometry shader emits triangle strips, we need to
915 * track which primitive is odd and swap vertex indices to get
916 * the correct vertex order.
917 */
918 LLVMValueRef is_odd = ctx->i1false;
919 if (stream == 0 && u_vertices_per_prim(sel->gs_output_prim) == 3) {
920 tmp = LLVMBuildAnd(builder, curverts, ctx->i32_1, "");
921 is_odd = LLVMBuildICmp(builder, LLVMIntEQ, tmp, ctx->i32_1, "");
922 }
923
924 tmp = LLVMBuildAdd(builder, curverts, ctx->ac.i32_1, "");
925 LLVMBuildStore(builder, tmp, ctx->gs_curprim_verts[stream]);
926
927 /* The per-vertex primitive flag encoding:
928 * bit 0: whether this vertex finishes a primitive
929 * bit 1: whether the primitive is odd (if we are emitting triangle strips)
930 */
931 tmp = LLVMBuildZExt(builder, iscompleteprim, ctx->ac.i8, "");
932 tmp = LLVMBuildOr(builder, tmp,
933 LLVMBuildShl(builder,
934 LLVMBuildZExt(builder, is_odd, ctx->ac.i8, ""),
935 ctx->ac.i8_1, ""), "");
936 LLVMBuildStore(builder, tmp, ngg_gs_get_emit_primflag_ptr(ctx, vertexptr, stream));
937
938 tmp = LLVMBuildLoad(builder, ctx->gs_generated_prims[stream], "");
939 tmp = LLVMBuildAdd(builder, tmp, LLVMBuildZExt(builder, iscompleteprim, ctx->ac.i32, ""), "");
940 LLVMBuildStore(builder, tmp, ctx->gs_generated_prims[stream]);
941
942 ac_build_endif(&ctx->ac, 9001);
943 }
944
945 void gfx10_ngg_gs_emit_prologue(struct si_shader_context *ctx)
946 {
947 /* Zero out the part of LDS scratch that is used to accumulate the
948 * per-stream generated primitive count.
949 */
950 LLVMBuilderRef builder = ctx->ac.builder;
951 LLVMValueRef scratchptr = ctx->gs_ngg_scratch;
952 LLVMValueRef tid = get_thread_id_in_tg(ctx);
953 LLVMValueRef tmp;
954
955 tmp = LLVMBuildICmp(builder, LLVMIntULT, tid, LLVMConstInt(ctx->i32, 4, false), "");
956 ac_build_ifcc(&ctx->ac, tmp, 5090);
957 {
958 LLVMValueRef ptr = ac_build_gep0(&ctx->ac, scratchptr, tid);
959 LLVMBuildStore(builder, ctx->i32_0, ptr);
960 }
961 ac_build_endif(&ctx->ac, 5090);
962
963 ac_build_s_barrier(&ctx->ac);
964 }
965
966 void gfx10_ngg_gs_emit_epilogue(struct si_shader_context *ctx)
967 {
968 const struct si_shader_selector *sel = ctx->shader->selector;
969 const struct si_shader_info *info = &sel->info;
970 const unsigned verts_per_prim = u_vertices_per_prim(sel->gs_output_prim);
971 LLVMBuilderRef builder = ctx->ac.builder;
972 LLVMValueRef i8_0 = LLVMConstInt(ctx->ac.i8, 0, false);
973 LLVMValueRef tmp, tmp2;
974
975 /* Zero out remaining (non-emitted) primitive flags.
976 *
977 * Note: Alternatively, we could pass the relevant gs_next_vertex to
978 * the emit threads via LDS. This is likely worse in the expected
979 * typical case where each GS thread emits the full set of
980 * vertices.
981 */
982 for (unsigned stream = 0; stream < 4; ++stream) {
983 if (!info->num_stream_output_components[stream])
984 continue;
985
986 const LLVMValueRef gsthread = get_thread_id_in_tg(ctx);
987
988 ac_build_bgnloop(&ctx->ac, 5100);
989
990 const LLVMValueRef vertexidx =
991 LLVMBuildLoad(builder, ctx->gs_next_vertex[stream], "");
992 tmp = LLVMBuildICmp(builder, LLVMIntUGE, vertexidx,
993 LLVMConstInt(ctx->ac.i32, sel->gs_max_out_vertices, false), "");
994 ac_build_ifcc(&ctx->ac, tmp, 5101);
995 ac_build_break(&ctx->ac);
996 ac_build_endif(&ctx->ac, 5101);
997
998 tmp = LLVMBuildAdd(builder, vertexidx, ctx->ac.i32_1, "");
999 LLVMBuildStore(builder, tmp, ctx->gs_next_vertex[stream]);
1000
1001 tmp = ngg_gs_emit_vertex_ptr(ctx, gsthread, vertexidx);
1002 LLVMBuildStore(builder, i8_0, ngg_gs_get_emit_primflag_ptr(ctx, tmp, stream));
1003
1004 ac_build_endloop(&ctx->ac, 5100);
1005 }
1006
1007 /* Accumulate generated primitives counts across the entire threadgroup. */
1008 for (unsigned stream = 0; stream < 4; ++stream) {
1009 if (!info->num_stream_output_components[stream])
1010 continue;
1011
1012 LLVMValueRef numprims =
1013 LLVMBuildLoad(builder, ctx->gs_generated_prims[stream], "");
1014 numprims = ac_build_reduce(&ctx->ac, numprims, nir_op_iadd, ctx->ac.wave_size);
1015
1016 tmp = LLVMBuildICmp(builder, LLVMIntEQ, ac_get_thread_id(&ctx->ac), ctx->i32_0, "");
1017 ac_build_ifcc(&ctx->ac, tmp, 5105);
1018 {
1019 LLVMBuildAtomicRMW(builder, LLVMAtomicRMWBinOpAdd,
1020 ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch,
1021 LLVMConstInt(ctx->i32, stream, false)),
1022 numprims, LLVMAtomicOrderingMonotonic, false);
1023 }
1024 ac_build_endif(&ctx->ac, 5105);
1025 }
1026
1027 ac_build_endif(&ctx->ac, ctx->merged_wrap_if_label);
1028
1029 ac_build_s_barrier(&ctx->ac);
1030
1031 const LLVMValueRef tid = get_thread_id_in_tg(ctx);
1032 LLVMValueRef num_emit_threads = ngg_get_prim_cnt(ctx);
1033
1034 /* Streamout */
1035 if (sel->so.num_outputs) {
1036 struct ngg_streamout nggso = {};
1037
1038 nggso.num_vertices = LLVMConstInt(ctx->i32, verts_per_prim, false);
1039
1040 LLVMValueRef vertexptr = ngg_gs_vertex_ptr(ctx, tid);
1041 for (unsigned stream = 0; stream < 4; ++stream) {
1042 if (!info->num_stream_output_components[stream])
1043 continue;
1044
1045 tmp = LLVMBuildLoad(builder, ngg_gs_get_emit_primflag_ptr(ctx, vertexptr, stream), "");
1046 tmp = LLVMBuildTrunc(builder, tmp, ctx->i1, "");
1047 tmp2 = LLVMBuildICmp(builder, LLVMIntULT, tid, num_emit_threads, "");
1048 nggso.prim_enable[stream] = LLVMBuildAnd(builder, tmp, tmp2, "");
1049 }
1050
1051 for (unsigned i = 0; i < verts_per_prim; ++i) {
1052 tmp = LLVMBuildSub(builder, tid,
1053 LLVMConstInt(ctx->i32, verts_per_prim - i - 1, false), "");
1054 tmp = ngg_gs_vertex_ptr(ctx, tmp);
1055 nggso.vertices[i] = ac_build_gep0(&ctx->ac, tmp, ctx->i32_0);
1056 }
1057
1058 build_streamout(ctx, &nggso);
1059 }
1060
1061 /* Write shader query data. */
1062 if (ctx->screen->use_ngg_streamout) {
1063 tmp = si_unpack_param(ctx, ctx->vs_state_bits, 6, 1);
1064 tmp = LLVMBuildTrunc(builder, tmp, ctx->i1, "");
1065 ac_build_ifcc(&ctx->ac, tmp, 5109); /* if (STREAMOUT_QUERY_ENABLED) */
1066 unsigned num_query_comps = sel->so.num_outputs ? 8 : 4;
1067 tmp = LLVMBuildICmp(builder, LLVMIntULT, tid,
1068 LLVMConstInt(ctx->i32, num_query_comps, false), "");
1069 ac_build_ifcc(&ctx->ac, tmp, 5110);
1070 {
1071 LLVMValueRef offset;
1072 tmp = tid;
1073 if (sel->so.num_outputs)
1074 tmp = LLVMBuildAnd(builder, tmp, LLVMConstInt(ctx->i32, 3, false), "");
1075 offset = LLVMBuildNUWMul(builder, tmp, LLVMConstInt(ctx->i32, 32, false), "");
1076 if (sel->so.num_outputs) {
1077 tmp = LLVMBuildLShr(builder, tid, LLVMConstInt(ctx->i32, 2, false), "");
1078 tmp = LLVMBuildNUWMul(builder, tmp, LLVMConstInt(ctx->i32, 8, false), "");
1079 offset = LLVMBuildAdd(builder, offset, tmp, "");
1080 }
1081
1082 tmp = LLVMBuildLoad(builder, ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch, tid), "");
1083 LLVMValueRef args[] = {
1084 tmp,
1085 ngg_get_query_buf(ctx),
1086 offset,
1087 LLVMConstInt(ctx->i32, 16, false), /* soffset */
1088 ctx->i32_0, /* cachepolicy */
1089 };
1090 ac_build_intrinsic(&ctx->ac, "llvm.amdgcn.raw.buffer.atomic.add.i32",
1091 ctx->i32, args, 5, 0);
1092 }
1093 ac_build_endif(&ctx->ac, 5110);
1094 ac_build_endif(&ctx->ac, 5109);
1095 }
1096
1097 /* Determine vertex liveness. */
1098 LLVMValueRef vertliveptr = ac_build_alloca(&ctx->ac, ctx->ac.i1, "vertexlive");
1099
1100 tmp = LLVMBuildICmp(builder, LLVMIntULT, tid, num_emit_threads, "");
1101 ac_build_ifcc(&ctx->ac, tmp, 5120);
1102 {
1103 for (unsigned i = 0; i < verts_per_prim; ++i) {
1104 const LLVMValueRef primidx =
1105 LLVMBuildAdd(builder, tid,
1106 LLVMConstInt(ctx->ac.i32, i, false), "");
1107
1108 if (i > 0) {
1109 tmp = LLVMBuildICmp(builder, LLVMIntULT, primidx, num_emit_threads, "");
1110 ac_build_ifcc(&ctx->ac, tmp, 5121 + i);
1111 }
1112
1113 /* Load primitive liveness */
1114 tmp = ngg_gs_vertex_ptr(ctx, primidx);
1115 tmp = LLVMBuildLoad(builder, ngg_gs_get_emit_primflag_ptr(ctx, tmp, 0), "");
1116 const LLVMValueRef primlive =
1117 LLVMBuildTrunc(builder, tmp, ctx->ac.i1, "");
1118
1119 tmp = LLVMBuildLoad(builder, vertliveptr, "");
1120 tmp = LLVMBuildOr(builder, tmp, primlive, ""),
1121 LLVMBuildStore(builder, tmp, vertliveptr);
1122
1123 if (i > 0)
1124 ac_build_endif(&ctx->ac, 5121 + i);
1125 }
1126 }
1127 ac_build_endif(&ctx->ac, 5120);
1128
1129 /* Inclusive scan addition across the current wave. */
1130 LLVMValueRef vertlive = LLVMBuildLoad(builder, vertliveptr, "");
1131 struct ac_wg_scan vertlive_scan = {};
1132 vertlive_scan.op = nir_op_iadd;
1133 vertlive_scan.enable_reduce = true;
1134 vertlive_scan.enable_exclusive = true;
1135 vertlive_scan.src = vertlive;
1136 vertlive_scan.scratch = ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch, ctx->i32_0);
1137 vertlive_scan.waveidx = get_wave_id_in_tg(ctx);
1138 vertlive_scan.numwaves = get_tgsize(ctx);
1139 vertlive_scan.maxwaves = 8;
1140
1141 ac_build_wg_scan(&ctx->ac, &vertlive_scan);
1142
1143 /* Skip all exports (including index exports) when possible. At least on
1144 * early gfx10 revisions this is also to avoid hangs.
1145 */
1146 LLVMValueRef have_exports =
1147 LLVMBuildICmp(builder, LLVMIntNE, vertlive_scan.result_reduce, ctx->ac.i32_0, "");
1148 num_emit_threads =
1149 LLVMBuildSelect(builder, have_exports, num_emit_threads, ctx->ac.i32_0, "");
1150
1151 /* Allocate export space. Send this message as early as possible, to
1152 * hide the latency of the SQ <-> SPI roundtrip.
1153 *
1154 * Note: We could consider compacting primitives for export as well.
1155 * PA processes 1 non-null prim / clock, but it fetches 4 DW of
1156 * prim data per clock and skips null primitives at no additional
1157 * cost. So compacting primitives can only be beneficial when
1158 * there are 4 or more contiguous null primitives in the export
1159 * (in the common case of single-dword prim exports).
1160 */
1161 ac_build_sendmsg_gs_alloc_req(&ctx->ac, get_wave_id_in_tg(ctx),
1162 vertlive_scan.result_reduce, num_emit_threads);
1163
1164 /* Setup the reverse vertex compaction permutation. We re-use stream 1
1165 * of the primitive liveness flags, relying on the fact that each
1166 * threadgroup can have at most 256 threads. */
1167 ac_build_ifcc(&ctx->ac, vertlive, 5130);
1168 {
1169 tmp = ngg_gs_vertex_ptr(ctx, vertlive_scan.result_exclusive);
1170 tmp2 = LLVMBuildTrunc(builder, tid, ctx->ac.i8, "");
1171 LLVMBuildStore(builder, tmp2, ngg_gs_get_emit_primflag_ptr(ctx, tmp, 1));
1172 }
1173 ac_build_endif(&ctx->ac, 5130);
1174
1175 ac_build_s_barrier(&ctx->ac);
1176
1177 /* Export primitive data */
1178 tmp = LLVMBuildICmp(builder, LLVMIntULT, tid, num_emit_threads, "");
1179 ac_build_ifcc(&ctx->ac, tmp, 5140);
1180 {
1181 LLVMValueRef flags;
1182 struct ac_ngg_prim prim = {};
1183 prim.num_vertices = verts_per_prim;
1184
1185 tmp = ngg_gs_vertex_ptr(ctx, tid);
1186 flags = LLVMBuildLoad(builder, ngg_gs_get_emit_primflag_ptr(ctx, tmp, 0), "");
1187 prim.isnull = LLVMBuildNot(builder, LLVMBuildTrunc(builder, flags, ctx->i1, ""), "");
1188
1189 for (unsigned i = 0; i < verts_per_prim; ++i) {
1190 prim.index[i] = LLVMBuildSub(builder, vertlive_scan.result_exclusive,
1191 LLVMConstInt(ctx->ac.i32, verts_per_prim - i - 1, false), "");
1192 prim.edgeflag[i] = ctx->ac.i1false;
1193 }
1194
1195 /* Geometry shaders output triangle strips, but NGG expects triangles.
1196 * We need to change the vertex order for odd triangles to get correct
1197 * front/back facing by swapping 2 vertex indices, but we also have to
1198 * keep the provoking vertex in the same place.
1199 *
1200 * If the first vertex is provoking, swap index 1 and 2.
1201 * If the last vertex is provoking, swap index 0 and 1.
1202 */
1203 if (verts_per_prim == 3) {
1204 LLVMValueRef is_odd = LLVMBuildLShr(builder, flags, ctx->ac.i8_1, "");
1205 is_odd = LLVMBuildTrunc(builder, is_odd, ctx->i1, "");
1206 LLVMValueRef flatshade_first =
1207 LLVMBuildICmp(builder, LLVMIntEQ,
1208 si_unpack_param(ctx, ctx->vs_state_bits, 4, 2),
1209 ctx->i32_0, "");
1210
1211 struct ac_ngg_prim in = prim;
1212 prim.index[0] = LLVMBuildSelect(builder, flatshade_first,
1213 in.index[0],
1214 LLVMBuildSelect(builder, is_odd,
1215 in.index[1], in.index[0], ""), "");
1216 prim.index[1] = LLVMBuildSelect(builder, flatshade_first,
1217 LLVMBuildSelect(builder, is_odd,
1218 in.index[2], in.index[1], ""),
1219 LLVMBuildSelect(builder, is_odd,
1220 in.index[0], in.index[1], ""), "");
1221 prim.index[2] = LLVMBuildSelect(builder, flatshade_first,
1222 LLVMBuildSelect(builder, is_odd,
1223 in.index[1], in.index[2], ""),
1224 in.index[2], "");
1225 }
1226
1227 ac_build_export_prim(&ctx->ac, &prim);
1228 }
1229 ac_build_endif(&ctx->ac, 5140);
1230
1231 /* Export position and parameter data */
1232 tmp = LLVMBuildICmp(builder, LLVMIntULT, tid, vertlive_scan.result_reduce, "");
1233 ac_build_ifcc(&ctx->ac, tmp, 5145);
1234 {
1235 struct si_shader_output_values outputs[PIPE_MAX_SHADER_OUTPUTS];
1236
1237 tmp = ngg_gs_vertex_ptr(ctx, tid);
1238 tmp = LLVMBuildLoad(builder, ngg_gs_get_emit_primflag_ptr(ctx, tmp, 1), "");
1239 tmp = LLVMBuildZExt(builder, tmp, ctx->ac.i32, "");
1240 const LLVMValueRef vertexptr = ngg_gs_vertex_ptr(ctx, tmp);
1241
1242 unsigned out_idx = 0;
1243 for (unsigned i = 0; i < info->num_outputs; i++) {
1244 outputs[i].semantic_name = info->output_semantic_name[i];
1245 outputs[i].semantic_index = info->output_semantic_index[i];
1246
1247 for (unsigned j = 0; j < 4; j++, out_idx++) {
1248 tmp = ngg_gs_get_emit_output_ptr(ctx, vertexptr, out_idx);
1249 tmp = LLVMBuildLoad(builder, tmp, "");
1250 outputs[i].values[j] = ac_to_float(&ctx->ac, tmp);
1251 outputs[i].vertex_stream[j] =
1252 (info->output_streams[i] >> (2 * j)) & 3;
1253 }
1254 }
1255
1256 si_llvm_export_vs(ctx, outputs, info->num_outputs);
1257 }
1258 ac_build_endif(&ctx->ac, 5145);
1259 }
1260
1261 static void clamp_gsprims_to_esverts(unsigned *max_gsprims, unsigned max_esverts,
1262 unsigned min_verts_per_prim, bool use_adjacency)
1263 {
1264 unsigned max_reuse = max_esverts - min_verts_per_prim;
1265 if (use_adjacency)
1266 max_reuse /= 2;
1267 *max_gsprims = MIN2(*max_gsprims, 1 + max_reuse);
1268 }
1269
1270 /**
1271 * Determine subgroup information like maximum number of vertices and prims.
1272 *
1273 * This happens before the shader is uploaded, since LDS relocations during
1274 * upload depend on the subgroup size.
1275 */
1276 void gfx10_ngg_calculate_subgroup_info(struct si_shader *shader)
1277 {
1278 const struct si_shader_selector *gs_sel = shader->selector;
1279 const struct si_shader_selector *es_sel =
1280 shader->previous_stage_sel ? shader->previous_stage_sel : gs_sel;
1281 const enum pipe_shader_type gs_type = gs_sel->type;
1282 const unsigned gs_num_invocations = MAX2(gs_sel->gs_num_invocations, 1);
1283 const unsigned input_prim = si_get_input_prim(gs_sel);
1284 const bool use_adjacency = input_prim >= PIPE_PRIM_LINES_ADJACENCY &&
1285 input_prim <= PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY;
1286 const unsigned max_verts_per_prim = u_vertices_per_prim(input_prim);
1287 const unsigned min_verts_per_prim =
1288 gs_type == PIPE_SHADER_GEOMETRY ? max_verts_per_prim : 1;
1289
1290 /* All these are in dwords: */
1291 /* We can't allow using the whole LDS, because GS waves compete with
1292 * other shader stages for LDS space.
1293 *
1294 * TODO: We should really take the shader's internal LDS use into
1295 * account. The linker will fail if the size is greater than
1296 * 8K dwords.
1297 */
1298 const unsigned max_lds_size = 8 * 1024 - 768;
1299 const unsigned target_lds_size = max_lds_size;
1300 unsigned esvert_lds_size = 0;
1301 unsigned gsprim_lds_size = 0;
1302
1303 /* All these are per subgroup: */
1304 bool max_vert_out_per_gs_instance = false;
1305 unsigned max_esverts_base = 128;
1306 unsigned max_gsprims_base = 128; /* default prim group size clamp */
1307
1308 /* Hardware has the following non-natural restrictions on the value
1309 * of GE_CNTL.VERT_GRP_SIZE based on based on the primitive type of
1310 * the draw:
1311 * - at most 252 for any line input primitive type
1312 * - at most 251 for any quad input primitive type
1313 * - at most 251 for triangle strips with adjacency (this happens to
1314 * be the natural limit for triangle *lists* with adjacency)
1315 */
1316 max_esverts_base = MIN2(max_esverts_base, 251 + max_verts_per_prim - 1);
1317
1318 if (gs_type == PIPE_SHADER_GEOMETRY) {
1319 unsigned max_out_verts_per_gsprim =
1320 gs_sel->gs_max_out_vertices * gs_num_invocations;
1321
1322 if (max_out_verts_per_gsprim <= 256) {
1323 if (max_out_verts_per_gsprim) {
1324 max_gsprims_base = MIN2(max_gsprims_base,
1325 256 / max_out_verts_per_gsprim);
1326 }
1327 } else {
1328 /* Use special multi-cycling mode in which each GS
1329 * instance gets its own subgroup. Does not work with
1330 * tessellation. */
1331 max_vert_out_per_gs_instance = true;
1332 max_gsprims_base = 1;
1333 max_out_verts_per_gsprim = gs_sel->gs_max_out_vertices;
1334 }
1335
1336 esvert_lds_size = es_sel->esgs_itemsize / 4;
1337 gsprim_lds_size = (gs_sel->gsvs_vertex_size / 4 + 1) * max_out_verts_per_gsprim;
1338 } else {
1339 /* VS and TES. */
1340 /* LDS size for passing data from ES to GS. */
1341 esvert_lds_size = ngg_nogs_vertex_size(shader);
1342 }
1343
1344 unsigned max_gsprims = max_gsprims_base;
1345 unsigned max_esverts = max_esverts_base;
1346
1347 if (esvert_lds_size)
1348 max_esverts = MIN2(max_esverts, target_lds_size / esvert_lds_size);
1349 if (gsprim_lds_size)
1350 max_gsprims = MIN2(max_gsprims, target_lds_size / gsprim_lds_size);
1351
1352 max_esverts = MIN2(max_esverts, max_gsprims * max_verts_per_prim);
1353 clamp_gsprims_to_esverts(&max_gsprims, max_esverts, min_verts_per_prim, use_adjacency);
1354 assert(max_esverts >= max_verts_per_prim && max_gsprims >= 1);
1355
1356 if (esvert_lds_size || gsprim_lds_size) {
1357 /* Now that we have a rough proportionality between esverts
1358 * and gsprims based on the primitive type, scale both of them
1359 * down simultaneously based on required LDS space.
1360 *
1361 * We could be smarter about this if we knew how much vertex
1362 * reuse to expect.
1363 */
1364 unsigned lds_total = max_esverts * esvert_lds_size +
1365 max_gsprims * gsprim_lds_size;
1366 if (lds_total > target_lds_size) {
1367 max_esverts = max_esverts * target_lds_size / lds_total;
1368 max_gsprims = max_gsprims * target_lds_size / lds_total;
1369
1370 max_esverts = MIN2(max_esverts, max_gsprims * max_verts_per_prim);
1371 clamp_gsprims_to_esverts(&max_gsprims, max_esverts,
1372 min_verts_per_prim, use_adjacency);
1373 assert(max_esverts >= max_verts_per_prim && max_gsprims >= 1);
1374 }
1375 }
1376
1377 /* Round up towards full wave sizes for better ALU utilization. */
1378 if (!max_vert_out_per_gs_instance) {
1379 const unsigned wavesize = gs_sel->screen->ge_wave_size;
1380 unsigned orig_max_esverts;
1381 unsigned orig_max_gsprims;
1382 do {
1383 orig_max_esverts = max_esverts;
1384 orig_max_gsprims = max_gsprims;
1385
1386 max_esverts = align(max_esverts, wavesize);
1387 max_esverts = MIN2(max_esverts, max_esverts_base);
1388 if (esvert_lds_size)
1389 max_esverts = MIN2(max_esverts,
1390 (max_lds_size - max_gsprims * gsprim_lds_size) /
1391 esvert_lds_size);
1392 max_esverts = MIN2(max_esverts, max_gsprims * max_verts_per_prim);
1393
1394 max_gsprims = align(max_gsprims, wavesize);
1395 max_gsprims = MIN2(max_gsprims, max_gsprims_base);
1396 if (gsprim_lds_size)
1397 max_gsprims = MIN2(max_gsprims,
1398 (max_lds_size - max_esverts * esvert_lds_size) /
1399 gsprim_lds_size);
1400 clamp_gsprims_to_esverts(&max_gsprims, max_esverts,
1401 min_verts_per_prim, use_adjacency);
1402 assert(max_esverts >= max_verts_per_prim && max_gsprims >= 1);
1403 } while (orig_max_esverts != max_esverts || orig_max_gsprims != max_gsprims);
1404 }
1405
1406 /* Hardware restriction: minimum value of max_esverts */
1407 max_esverts = MAX2(max_esverts, 23 + max_verts_per_prim);
1408
1409 unsigned max_out_vertices =
1410 max_vert_out_per_gs_instance ? gs_sel->gs_max_out_vertices :
1411 gs_type == PIPE_SHADER_GEOMETRY ?
1412 max_gsprims * gs_num_invocations * gs_sel->gs_max_out_vertices :
1413 max_esverts;
1414 assert(max_out_vertices <= 256);
1415
1416 unsigned prim_amp_factor = 1;
1417 if (gs_type == PIPE_SHADER_GEOMETRY) {
1418 /* Number of output primitives per GS input primitive after
1419 * GS instancing. */
1420 prim_amp_factor = gs_sel->gs_max_out_vertices;
1421 }
1422
1423 /* The GE only checks against the maximum number of ES verts after
1424 * allocating a full GS primitive. So we need to ensure that whenever
1425 * this check passes, there is enough space for a full primitive without
1426 * vertex reuse.
1427 */
1428 shader->ngg.hw_max_esverts = max_esverts - max_verts_per_prim + 1;
1429 shader->ngg.max_gsprims = max_gsprims;
1430 shader->ngg.max_out_verts = max_out_vertices;
1431 shader->ngg.prim_amp_factor = prim_amp_factor;
1432 shader->ngg.max_vert_out_per_gs_instance = max_vert_out_per_gs_instance;
1433
1434 shader->gs_info.esgs_ring_size = 4 * max_esverts * esvert_lds_size;
1435 shader->ngg.ngg_emit_size = max_gsprims * gsprim_lds_size;
1436
1437 assert(shader->ngg.hw_max_esverts >= 24); /* HW limitation */
1438 }