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 "ac_llvm_cull.h"
25 #include "si_pipe.h"
26 #include "si_shader_internal.h"
27 #include "sid.h"
28 #include "util/u_memory.h"
29 #include "util/u_prim.h"
30
get_wave_id_in_tg(struct si_shader_context * ctx)31 static LLVMValueRef get_wave_id_in_tg(struct si_shader_context *ctx)
32 {
33 return si_unpack_param(ctx, ctx->args.merged_wave_info, 24, 4);
34 }
35
get_tgsize(struct si_shader_context * ctx)36 static LLVMValueRef get_tgsize(struct si_shader_context *ctx)
37 {
38 return si_unpack_param(ctx, ctx->args.merged_wave_info, 28, 4);
39 }
40
get_thread_id_in_tg(struct si_shader_context * ctx)41 static LLVMValueRef get_thread_id_in_tg(struct si_shader_context *ctx)
42 {
43 LLVMBuilderRef builder = ctx->ac.builder;
44 LLVMValueRef tmp;
45 tmp = LLVMBuildMul(builder, get_wave_id_in_tg(ctx),
46 LLVMConstInt(ctx->ac.i32, ctx->ac.wave_size, false), "");
47 return LLVMBuildAdd(builder, tmp, ac_get_thread_id(&ctx->ac), "");
48 }
49
ngg_get_vtx_cnt(struct si_shader_context * ctx)50 static LLVMValueRef ngg_get_vtx_cnt(struct si_shader_context *ctx)
51 {
52 return si_unpack_param(ctx, ctx->args.gs_tg_info, 12, 9);
53 }
54
ngg_get_prim_cnt(struct si_shader_context * ctx)55 static LLVMValueRef ngg_get_prim_cnt(struct si_shader_context *ctx)
56 {
57 return si_unpack_param(ctx, ctx->args.gs_tg_info, 22, 9);
58 }
59
ngg_get_ordered_id(struct si_shader_context * ctx)60 static LLVMValueRef ngg_get_ordered_id(struct si_shader_context *ctx)
61 {
62 return si_unpack_param(ctx, ctx->args.gs_tg_info, 0, 12);
63 }
64
ngg_get_query_buf(struct si_shader_context * ctx)65 static LLVMValueRef ngg_get_query_buf(struct si_shader_context *ctx)
66 {
67 LLVMValueRef buf_ptr = ac_get_arg(&ctx->ac, ctx->internal_bindings);
68
69 return ac_build_load_to_sgpr(&ctx->ac, buf_ptr,
70 LLVMConstInt(ctx->ac.i32, GFX10_GS_QUERY_BUF, false));
71 }
72
73 /**
74 * Return the number of vertices as a constant in \p num_vertices,
75 * and return a more precise value as LLVMValueRef from the function.
76 */
ngg_get_vertices_per_prim(struct si_shader_context * ctx,unsigned * num_vertices)77 static LLVMValueRef ngg_get_vertices_per_prim(struct si_shader_context *ctx, unsigned *num_vertices)
78 {
79 const struct si_shader_info *info = &ctx->shader->selector->info;
80
81 if (ctx->stage == MESA_SHADER_VERTEX) {
82 if (info->base.vs.blit_sgprs_amd) {
83 /* Blits always use axis-aligned rectangles with 3 vertices. */
84 *num_vertices = 3;
85 return LLVMConstInt(ctx->ac.i32, 3, 0);
86 } else if (ctx->shader->key.opt.ngg_culling & SI_NGG_CULL_LINES) {
87 *num_vertices = 2;
88 return LLVMConstInt(ctx->ac.i32, 2, 0);
89 } else {
90 /* We always build up all three indices for the prim export
91 * independent of the primitive type. The additional garbage
92 * data shouldn't hurt. This is used by exports and streamout.
93 */
94 *num_vertices = 3;
95
96 /* Extract OUTPRIM field. */
97 LLVMValueRef num = si_unpack_param(ctx, ctx->vs_state_bits, 2, 2);
98 return LLVMBuildAdd(ctx->ac.builder, num, ctx->ac.i32_1, "");
99 }
100 } else {
101 assert(ctx->stage == MESA_SHADER_TESS_EVAL);
102
103 if (info->base.tess.point_mode)
104 *num_vertices = 1;
105 else if (info->base.tess.primitive_mode == GL_LINES)
106 *num_vertices = 2;
107 else
108 *num_vertices = 3;
109
110 return LLVMConstInt(ctx->ac.i32, *num_vertices, false);
111 }
112 }
113
gfx10_ngg_export_prim_early(struct si_shader * shader)114 bool gfx10_ngg_export_prim_early(struct si_shader *shader)
115 {
116 struct si_shader_selector *sel = shader->selector;
117
118 assert(shader->key.as_ngg && !shader->key.as_es);
119
120 return sel->info.stage != MESA_SHADER_GEOMETRY &&
121 !gfx10_ngg_writes_user_edgeflags(shader);
122 }
123
gfx10_ngg_build_sendmsg_gs_alloc_req(struct si_shader_context * ctx)124 void gfx10_ngg_build_sendmsg_gs_alloc_req(struct si_shader_context *ctx)
125 {
126 /* Newer chips can use PRIMGEN_PASSTHRU_NO_MSG to skip gs_alloc_req for NGG passthrough. */
127 if (gfx10_is_ngg_passthrough(ctx->shader) &&
128 ctx->screen->info.family >= CHIP_DIMGREY_CAVEFISH)
129 return;
130
131 ac_build_sendmsg_gs_alloc_req(&ctx->ac, get_wave_id_in_tg(ctx), ngg_get_vtx_cnt(ctx),
132 ngg_get_prim_cnt(ctx));
133 }
134
gfx10_ngg_build_export_prim(struct si_shader_context * ctx,LLVMValueRef user_edgeflags[3],LLVMValueRef prim_passthrough)135 void gfx10_ngg_build_export_prim(struct si_shader_context *ctx, LLVMValueRef user_edgeflags[3],
136 LLVMValueRef prim_passthrough)
137 {
138 LLVMBuilderRef builder = ctx->ac.builder;
139
140 if (gfx10_is_ngg_passthrough(ctx->shader) || ctx->shader->key.opt.ngg_culling) {
141 ac_build_ifcc(&ctx->ac, si_is_gs_thread(ctx), 6001);
142 {
143 struct ac_ngg_prim prim = {};
144
145 if (prim_passthrough)
146 prim.passthrough = prim_passthrough;
147 else
148 prim.passthrough = ac_get_arg(&ctx->ac, ctx->args.gs_vtx_offset[0]);
149
150 /* This is only used with NGG culling, which returns the NGG
151 * passthrough prim export encoding.
152 */
153 if (gfx10_ngg_writes_user_edgeflags(ctx->shader)) {
154 unsigned all_bits_no_edgeflags = ~SI_NGG_PRIM_EDGE_FLAG_BITS;
155 LLVMValueRef edgeflags = LLVMConstInt(ctx->ac.i32, all_bits_no_edgeflags, 0);
156
157 unsigned num_vertices;
158 ngg_get_vertices_per_prim(ctx, &num_vertices);
159
160 for (unsigned i = 0; i < num_vertices; i++) {
161 unsigned shift = 9 + i * 10;
162 LLVMValueRef edge;
163
164 edge = LLVMBuildLoad(builder, user_edgeflags[i], "");
165 edge = LLVMBuildZExt(builder, edge, ctx->ac.i32, "");
166 edge = LLVMBuildShl(builder, edge, LLVMConstInt(ctx->ac.i32, shift, 0), "");
167 edgeflags = LLVMBuildOr(builder, edgeflags, edge, "");
168 }
169 prim.passthrough = LLVMBuildAnd(builder, prim.passthrough, edgeflags, "");
170 }
171
172 ac_build_export_prim(&ctx->ac, &prim);
173 }
174 ac_build_endif(&ctx->ac, 6001);
175 return;
176 }
177
178 ac_build_ifcc(&ctx->ac, si_is_gs_thread(ctx), 6001);
179 {
180 struct ac_ngg_prim prim = {};
181
182 ngg_get_vertices_per_prim(ctx, &prim.num_vertices);
183
184 prim.isnull = ctx->ac.i1false;
185
186 if (gfx10_edgeflags_have_effect(ctx->shader))
187 prim.edgeflags = ac_pack_edgeflags_for_export(&ctx->ac, &ctx->args);
188 else
189 prim.edgeflags = ctx->ac.i32_0;
190
191 for (unsigned i = 0; i < prim.num_vertices; ++i)
192 prim.index[i] = si_unpack_param(ctx, ctx->args.gs_vtx_offset[i / 2], (i & 1) * 16, 16);
193
194 if (gfx10_ngg_writes_user_edgeflags(ctx->shader)) {
195 LLVMValueRef edgeflags = ctx->ac.i32_0;
196
197 for (unsigned i = 0; i < prim.num_vertices; ++i) {
198 LLVMValueRef edge;
199
200 edge = LLVMBuildLoad(ctx->ac.builder, user_edgeflags[i], "");
201 edge = LLVMBuildZExt(ctx->ac.builder, edge, ctx->ac.i32, "");
202 edge = LLVMBuildShl(ctx->ac.builder, edge, LLVMConstInt(ctx->ac.i32, 9 + i*10, 0), "");
203 edgeflags = LLVMBuildOr(ctx->ac.builder, edgeflags, edge, "");
204 }
205 prim.edgeflags = LLVMBuildAnd(ctx->ac.builder, prim.edgeflags, edgeflags, "");
206 }
207
208 ac_build_export_prim(&ctx->ac, &prim);
209 }
210 ac_build_endif(&ctx->ac, 6001);
211 }
212
build_streamout_vertex(struct si_shader_context * ctx,LLVMValueRef * so_buffer,LLVMValueRef * wg_offset_dw,unsigned stream,LLVMValueRef offset_vtx,LLVMValueRef vertexptr)213 static void build_streamout_vertex(struct si_shader_context *ctx, LLVMValueRef *so_buffer,
214 LLVMValueRef *wg_offset_dw, unsigned stream,
215 LLVMValueRef offset_vtx, LLVMValueRef vertexptr)
216 {
217 struct si_shader_info *info = &ctx->shader->selector->info;
218 struct pipe_stream_output_info *so = &ctx->shader->selector->so;
219 LLVMBuilderRef builder = ctx->ac.builder;
220 LLVMValueRef offset[4] = {};
221 LLVMValueRef tmp;
222
223 for (unsigned buffer = 0; buffer < 4; ++buffer) {
224 if (!wg_offset_dw[buffer])
225 continue;
226
227 tmp = LLVMBuildMul(builder, offset_vtx, LLVMConstInt(ctx->ac.i32, so->stride[buffer], false),
228 "");
229 tmp = LLVMBuildAdd(builder, wg_offset_dw[buffer], tmp, "");
230 offset[buffer] = LLVMBuildShl(builder, tmp, LLVMConstInt(ctx->ac.i32, 2, false), "");
231 }
232
233 for (unsigned i = 0; i < so->num_outputs; ++i) {
234 if (so->output[i].stream != stream)
235 continue;
236
237 unsigned reg = so->output[i].register_index;
238 struct si_shader_output_values out;
239 out.semantic = info->output_semantic[reg];
240
241 for (unsigned comp = 0; comp < 4; comp++) {
242 tmp = ac_build_gep0(&ctx->ac, vertexptr, LLVMConstInt(ctx->ac.i32, 4 * reg + comp, false));
243 out.values[comp] = LLVMBuildLoad(builder, tmp, "");
244 out.vertex_stream[comp] = (info->output_streams[reg] >> (2 * comp)) & 3;
245 }
246
247 si_llvm_streamout_store_output(ctx, so_buffer, offset, &so->output[i], &out);
248 }
249 }
250
251 struct ngg_streamout {
252 LLVMValueRef num_vertices;
253
254 /* per-thread data */
255 LLVMValueRef prim_enable[4]; /* i1 per stream */
256 LLVMValueRef vertices[3]; /* [N x i32] addrspace(LDS)* */
257
258 /* Output */
259 LLVMValueRef emit[4]; /* per-stream emitted primitives (only valid for used streams) */
260 };
261
262 /**
263 * Build streamout logic.
264 *
265 * Implies a barrier.
266 *
267 * Writes number of emitted primitives to gs_ngg_scratch[4:8].
268 *
269 * Clobbers gs_ngg_scratch[8:].
270 */
build_streamout(struct si_shader_context * ctx,struct ngg_streamout * nggso)271 static void build_streamout(struct si_shader_context *ctx, struct ngg_streamout *nggso)
272 {
273 struct si_shader_info *info = &ctx->shader->selector->info;
274 struct pipe_stream_output_info *so = &ctx->shader->selector->so;
275 LLVMBuilderRef builder = ctx->ac.builder;
276 LLVMValueRef buf_ptr = ac_get_arg(&ctx->ac, ctx->internal_bindings);
277 LLVMValueRef tid = get_thread_id_in_tg(ctx);
278 LLVMValueRef tmp, tmp2;
279 LLVMValueRef i32_2 = LLVMConstInt(ctx->ac.i32, 2, false);
280 LLVMValueRef i32_4 = LLVMConstInt(ctx->ac.i32, 4, false);
281 LLVMValueRef i32_8 = LLVMConstInt(ctx->ac.i32, 8, false);
282 LLVMValueRef so_buffer[4] = {};
283 unsigned max_num_vertices = 1 + (nggso->vertices[1] ? 1 : 0) + (nggso->vertices[2] ? 1 : 0);
284 LLVMValueRef prim_stride_dw[4] = {};
285 LLVMValueRef prim_stride_dw_vgpr = LLVMGetUndef(ctx->ac.i32);
286 int stream_for_buffer[4] = {-1, -1, -1, -1};
287 unsigned bufmask_for_stream[4] = {};
288 bool isgs = ctx->stage == MESA_SHADER_GEOMETRY;
289 unsigned scratch_emit_base = isgs ? 4 : 0;
290 LLVMValueRef scratch_emit_basev = isgs ? i32_4 : ctx->ac.i32_0;
291 unsigned scratch_offset_base = isgs ? 8 : 4;
292 LLVMValueRef scratch_offset_basev = isgs ? i32_8 : i32_4;
293
294 ac_llvm_add_target_dep_function_attr(ctx->main_fn, "amdgpu-gds-size", 256);
295
296 /* Determine the mapping of streamout buffers to vertex streams. */
297 for (unsigned i = 0; i < so->num_outputs; ++i) {
298 unsigned buf = so->output[i].output_buffer;
299 unsigned stream = so->output[i].stream;
300 assert(stream_for_buffer[buf] < 0 || stream_for_buffer[buf] == stream);
301 stream_for_buffer[buf] = stream;
302 bufmask_for_stream[stream] |= 1 << buf;
303 }
304
305 for (unsigned buffer = 0; buffer < 4; ++buffer) {
306 if (stream_for_buffer[buffer] == -1)
307 continue;
308
309 assert(so->stride[buffer]);
310
311 tmp = LLVMConstInt(ctx->ac.i32, so->stride[buffer], false);
312 prim_stride_dw[buffer] = LLVMBuildMul(builder, tmp, nggso->num_vertices, "");
313 prim_stride_dw_vgpr =
314 ac_build_writelane(&ctx->ac, prim_stride_dw_vgpr, prim_stride_dw[buffer],
315 LLVMConstInt(ctx->ac.i32, buffer, false));
316
317 so_buffer[buffer] = ac_build_load_to_sgpr(
318 &ctx->ac, buf_ptr, LLVMConstInt(ctx->ac.i32, SI_VS_STREAMOUT_BUF0 + buffer, false));
319 }
320
321 tmp = LLVMBuildICmp(builder, LLVMIntEQ, get_wave_id_in_tg(ctx), ctx->ac.i32_0, "");
322 ac_build_ifcc(&ctx->ac, tmp, 5200);
323 {
324 LLVMTypeRef gdsptr = LLVMPointerType(ctx->ac.i32, AC_ADDR_SPACE_GDS);
325 LLVMValueRef gdsbase = LLVMBuildIntToPtr(builder, ctx->ac.i32_0, gdsptr, "");
326
327 /* Advance the streamout offsets in GDS. */
328 LLVMValueRef offsets_vgpr = ac_build_alloca_undef(&ctx->ac, ctx->ac.i32, "");
329 LLVMValueRef generated_by_stream_vgpr = ac_build_alloca_undef(&ctx->ac, ctx->ac.i32, "");
330
331 tmp = LLVMBuildICmp(builder, LLVMIntULT, ac_get_thread_id(&ctx->ac), i32_4, "");
332 ac_build_ifcc(&ctx->ac, tmp, 5210);
333 {
334 if (isgs) {
335 tmp = ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch, tid);
336 tmp = LLVMBuildLoad(builder, tmp, "");
337 } else {
338 tmp = ac_build_writelane(&ctx->ac, ctx->ac.i32_0, ngg_get_prim_cnt(ctx), ctx->ac.i32_0);
339 }
340 LLVMBuildStore(builder, tmp, generated_by_stream_vgpr);
341
342 unsigned swizzle[4];
343 int unused_stream = -1;
344 for (unsigned stream = 0; stream < 4; ++stream) {
345 if (!info->num_stream_output_components[stream]) {
346 unused_stream = stream;
347 break;
348 }
349 }
350 for (unsigned buffer = 0; buffer < 4; ++buffer) {
351 if (stream_for_buffer[buffer] >= 0) {
352 swizzle[buffer] = stream_for_buffer[buffer];
353 } else {
354 assert(unused_stream >= 0);
355 swizzle[buffer] = unused_stream;
356 }
357 }
358
359 tmp = ac_build_quad_swizzle(&ctx->ac, tmp, swizzle[0], swizzle[1], swizzle[2], swizzle[3]);
360 tmp = LLVMBuildMul(builder, tmp, prim_stride_dw_vgpr, "");
361
362 LLVMValueRef args[] = {
363 LLVMBuildIntToPtr(builder, ngg_get_ordered_id(ctx), gdsptr, ""),
364 tmp,
365 ctx->ac.i32_0, // ordering
366 ctx->ac.i32_0, // scope
367 ctx->ac.i1false, // isVolatile
368 LLVMConstInt(ctx->ac.i32, 4 << 24, false), // OA index
369 ctx->ac.i1true, // wave release
370 ctx->ac.i1true, // wave done
371 };
372 tmp = ac_build_intrinsic(&ctx->ac, "llvm.amdgcn.ds.ordered.add", ctx->ac.i32, args,
373 ARRAY_SIZE(args), 0);
374
375 /* Keep offsets in a VGPR for quick retrieval via readlane by
376 * the first wave for bounds checking, and also store in LDS
377 * for retrieval by all waves later. */
378 LLVMBuildStore(builder, tmp, offsets_vgpr);
379
380 tmp2 = LLVMBuildAdd(builder, ac_get_thread_id(&ctx->ac), scratch_offset_basev, "");
381 tmp2 = ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch, tmp2);
382 LLVMBuildStore(builder, tmp, tmp2);
383 }
384 ac_build_endif(&ctx->ac, 5210);
385
386 /* Determine the max emit per buffer. This is done via the SALU, in part
387 * because LLVM can't generate divide-by-multiply if we try to do this
388 * via VALU with one lane per buffer.
389 */
390 LLVMValueRef max_emit[4] = {};
391 for (unsigned buffer = 0; buffer < 4; ++buffer) {
392 if (stream_for_buffer[buffer] == -1)
393 continue;
394
395 LLVMValueRef bufsize_dw = LLVMBuildLShr(
396 builder, LLVMBuildExtractElement(builder, so_buffer[buffer], i32_2, ""), i32_2, "");
397
398 tmp = LLVMBuildLoad(builder, offsets_vgpr, "");
399 LLVMValueRef offset_dw =
400 ac_build_readlane(&ctx->ac, tmp, LLVMConstInt(ctx->ac.i32, buffer, false));
401
402 tmp = LLVMBuildSub(builder, bufsize_dw, offset_dw, "");
403 tmp = LLVMBuildUDiv(builder, tmp, prim_stride_dw[buffer], "");
404
405 tmp2 = LLVMBuildICmp(builder, LLVMIntULT, bufsize_dw, offset_dw, "");
406 max_emit[buffer] = LLVMBuildSelect(builder, tmp2, ctx->ac.i32_0, tmp, "");
407 }
408
409 /* Determine the number of emitted primitives per stream and fixup the
410 * GDS counter if necessary.
411 *
412 * This is complicated by the fact that a single stream can emit to
413 * multiple buffers (but luckily not vice versa).
414 */
415 LLVMValueRef emit_vgpr = ctx->ac.i32_0;
416
417 for (unsigned stream = 0; stream < 4; ++stream) {
418 if (!info->num_stream_output_components[stream])
419 continue;
420
421 tmp = LLVMBuildLoad(builder, generated_by_stream_vgpr, "");
422 LLVMValueRef generated =
423 ac_build_readlane(&ctx->ac, tmp, LLVMConstInt(ctx->ac.i32, stream, false));
424
425 LLVMValueRef emit = generated;
426 for (unsigned buffer = 0; buffer < 4; ++buffer) {
427 if (stream_for_buffer[buffer] == stream)
428 emit = ac_build_umin(&ctx->ac, emit, max_emit[buffer]);
429 }
430
431 emit_vgpr =
432 ac_build_writelane(&ctx->ac, emit_vgpr, emit, LLVMConstInt(ctx->ac.i32, stream, false));
433
434 /* Fixup the offset using a plain GDS atomic if we overflowed. */
435 tmp = LLVMBuildICmp(builder, LLVMIntULT, emit, generated, "");
436 ac_build_ifcc(&ctx->ac, tmp, 5221); /* scalar branch */
437 tmp = LLVMBuildLShr(builder, LLVMConstInt(ctx->ac.i32, bufmask_for_stream[stream], false),
438 ac_get_thread_id(&ctx->ac), "");
439 tmp = LLVMBuildTrunc(builder, tmp, ctx->ac.i1, "");
440 ac_build_ifcc(&ctx->ac, tmp, 5222);
441 {
442 tmp = LLVMBuildSub(builder, generated, emit, "");
443 tmp = LLVMBuildMul(builder, tmp, prim_stride_dw_vgpr, "");
444 tmp2 = LLVMBuildGEP(builder, gdsbase, &tid, 1, "");
445 LLVMBuildAtomicRMW(builder, LLVMAtomicRMWBinOpSub, tmp2, tmp,
446 LLVMAtomicOrderingMonotonic, false);
447 }
448 ac_build_endif(&ctx->ac, 5222);
449 ac_build_endif(&ctx->ac, 5221);
450 }
451
452 tmp = LLVMBuildICmp(builder, LLVMIntULT, ac_get_thread_id(&ctx->ac), i32_4, "");
453 ac_build_ifcc(&ctx->ac, tmp, 5225);
454 {
455 tmp = LLVMBuildAdd(builder, ac_get_thread_id(&ctx->ac), scratch_emit_basev, "");
456 tmp = ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch, tmp);
457 LLVMBuildStore(builder, emit_vgpr, tmp);
458 }
459 ac_build_endif(&ctx->ac, 5225);
460 }
461 ac_build_endif(&ctx->ac, 5200);
462
463 /* Determine the workgroup-relative per-thread / primitive offset into
464 * the streamout buffers */
465 struct ac_wg_scan primemit_scan[4] = {};
466
467 if (isgs) {
468 for (unsigned stream = 0; stream < 4; ++stream) {
469 if (!info->num_stream_output_components[stream])
470 continue;
471
472 primemit_scan[stream].enable_exclusive = true;
473 primemit_scan[stream].op = nir_op_iadd;
474 primemit_scan[stream].src = nggso->prim_enable[stream];
475 primemit_scan[stream].scratch = ac_build_gep0(
476 &ctx->ac, ctx->gs_ngg_scratch, LLVMConstInt(ctx->ac.i32, 12 + 8 * stream, false));
477 primemit_scan[stream].waveidx = get_wave_id_in_tg(ctx);
478 primemit_scan[stream].numwaves = get_tgsize(ctx);
479 if (ctx->stage == MESA_SHADER_GEOMETRY) {
480 /* ngg_subgroup_size is only the input size. GS can always generate up to 256 vertices. */
481 primemit_scan[stream].maxwaves = DIV_ROUND_UP(256, ctx->ac.wave_size);
482 } else {
483 primemit_scan[stream].maxwaves = DIV_ROUND_UP(ctx->screen->ngg_subgroup_size,
484 ctx->ac.wave_size);
485 }
486 ac_build_wg_scan_top(&ctx->ac, &primemit_scan[stream]);
487 }
488 }
489
490 ac_build_s_barrier(&ctx->ac);
491
492 /* Fetch the per-buffer offsets and per-stream emit counts in all waves. */
493 LLVMValueRef wgoffset_dw[4] = {};
494
495 {
496 LLVMValueRef scratch_vgpr;
497
498 tmp = ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch, ac_get_thread_id(&ctx->ac));
499 scratch_vgpr = LLVMBuildLoad(builder, tmp, "");
500
501 for (unsigned buffer = 0; buffer < 4; ++buffer) {
502 if (stream_for_buffer[buffer] >= 0) {
503 wgoffset_dw[buffer] =
504 ac_build_readlane(&ctx->ac, scratch_vgpr,
505 LLVMConstInt(ctx->ac.i32, scratch_offset_base + buffer, false));
506 }
507 }
508
509 for (unsigned stream = 0; stream < 4; ++stream) {
510 if (info->num_stream_output_components[stream]) {
511 nggso->emit[stream] =
512 ac_build_readlane(&ctx->ac, scratch_vgpr,
513 LLVMConstInt(ctx->ac.i32, scratch_emit_base + stream, false));
514 }
515 }
516 }
517
518 /* Write out primitive data */
519 for (unsigned stream = 0; stream < 4; ++stream) {
520 if (!info->num_stream_output_components[stream])
521 continue;
522
523 if (isgs) {
524 ac_build_wg_scan_bottom(&ctx->ac, &primemit_scan[stream]);
525 } else {
526 primemit_scan[stream].result_exclusive = tid;
527 }
528
529 tmp = LLVMBuildICmp(builder, LLVMIntULT, primemit_scan[stream].result_exclusive,
530 nggso->emit[stream], "");
531 tmp = LLVMBuildAnd(builder, tmp, nggso->prim_enable[stream], "");
532 ac_build_ifcc(&ctx->ac, tmp, 5240);
533 {
534 LLVMValueRef offset_vtx =
535 LLVMBuildMul(builder, primemit_scan[stream].result_exclusive, nggso->num_vertices, "");
536
537 for (unsigned i = 0; i < max_num_vertices; ++i) {
538 tmp = LLVMBuildICmp(builder, LLVMIntULT, LLVMConstInt(ctx->ac.i32, i, false),
539 nggso->num_vertices, "");
540 ac_build_ifcc(&ctx->ac, tmp, 5241);
541 build_streamout_vertex(ctx, so_buffer, wgoffset_dw, stream, offset_vtx,
542 nggso->vertices[i]);
543 ac_build_endif(&ctx->ac, 5241);
544 offset_vtx = LLVMBuildAdd(builder, offset_vtx, ctx->ac.i32_1, "");
545 }
546 }
547 ac_build_endif(&ctx->ac, 5240);
548 }
549 }
550
551 /* LDS layout of ES vertex data for NGG culling. */
552 enum
553 {
554 /* Byte 0: Boolean ES thread accepted (unculled) flag, and later the old
555 * ES thread ID. After vertex compaction, compacted ES threads
556 * store the old thread ID here to copy input VGPRs from uncompacted
557 * ES threads.
558 * Byte 1: New ES thread ID, loaded by GS to prepare the prim export value.
559 * Byte 2: TES rel patch ID
560 * Byte 3: Unused
561 */
562 lds_byte0_accept_flag = 0,
563 lds_byte1_new_thread_id,
564 lds_byte2_tes_rel_patch_id,
565 lds_byte3_unused,
566
567 lds_packed_data = 0, /* lds_byteN_... */
568 lds_pos_cull_x_div_w,
569 lds_pos_cull_y_div_w,
570 lds_pos_cull_w,
571
572 lds_pos_x = lds_packed_data + 1,
573 lds_pos_y,
574 lds_pos_z,
575 lds_pos_w,
576 /* If VS: */
577 lds_vertex_id,
578 lds_instance_id, /* optional */
579 /* If TES: */
580 lds_tes_u = lds_vertex_id,
581 lds_tes_v = lds_instance_id,
582 lds_tes_patch_id, /* optional */
583 };
584
si_build_gep_i8_var(struct si_shader_context * ctx,LLVMValueRef ptr,LLVMValueRef index)585 static LLVMValueRef si_build_gep_i8_var(struct si_shader_context *ctx, LLVMValueRef ptr,
586 LLVMValueRef index)
587 {
588 LLVMTypeRef pi8 = LLVMPointerType(ctx->ac.i8, AC_ADDR_SPACE_LDS);
589
590 return LLVMBuildGEP(ctx->ac.builder, LLVMBuildPointerCast(ctx->ac.builder, ptr, pi8, ""), &index,
591 1, "");
592 }
593
si_build_gep_i8(struct si_shader_context * ctx,LLVMValueRef ptr,unsigned byte_index)594 static LLVMValueRef si_build_gep_i8(struct si_shader_context *ctx, LLVMValueRef ptr,
595 unsigned byte_index)
596 {
597 assert(byte_index < 4);
598 return si_build_gep_i8_var(ctx, ptr, LLVMConstInt(ctx->ac.i32, byte_index, 0));
599 }
600
ngg_nogs_vertex_size(struct si_shader * shader)601 static unsigned ngg_nogs_vertex_size(struct si_shader *shader)
602 {
603 unsigned lds_vertex_size = 0;
604
605 /* The edgeflag is always stored in the last element that's also
606 * used for padding to reduce LDS bank conflicts. */
607 if (shader->selector->so.num_outputs)
608 lds_vertex_size = 4 * shader->selector->info.num_outputs + 1;
609 if (gfx10_ngg_writes_user_edgeflags(shader))
610 lds_vertex_size = MAX2(lds_vertex_size, 1);
611
612 /* LDS size for passing data from GS to ES.
613 * GS stores Primitive IDs into LDS at the address corresponding
614 * to the ES thread of the provoking vertex. All ES threads
615 * load and export PrimitiveID for their thread.
616 */
617 if (shader->selector->info.stage == MESA_SHADER_VERTEX && shader->key.mono.u.vs_export_prim_id)
618 lds_vertex_size = MAX2(lds_vertex_size, 1);
619
620 if (shader->key.opt.ngg_culling) {
621 if (shader->selector->info.stage == MESA_SHADER_VERTEX) {
622 STATIC_ASSERT(lds_instance_id + 1 == 7);
623 lds_vertex_size = MAX2(lds_vertex_size, 7);
624 } else {
625 assert(shader->selector->info.stage == MESA_SHADER_TESS_EVAL);
626
627 if (shader->selector->info.uses_primid || shader->key.mono.u.vs_export_prim_id) {
628 STATIC_ASSERT(lds_tes_patch_id + 2 == 9); /* +1 for LDS padding */
629 lds_vertex_size = MAX2(lds_vertex_size, 9);
630 } else {
631 STATIC_ASSERT(lds_tes_v + 1 == 7);
632 lds_vertex_size = MAX2(lds_vertex_size, 7);
633 }
634 }
635 }
636
637 return lds_vertex_size;
638 }
639
640 /**
641 * Returns an `[N x i32] addrspace(LDS)*` pointing at contiguous LDS storage
642 * for the vertex outputs.
643 */
ngg_nogs_vertex_ptr(struct si_shader_context * ctx,LLVMValueRef vtxid)644 static LLVMValueRef ngg_nogs_vertex_ptr(struct si_shader_context *ctx, LLVMValueRef vtxid)
645 {
646 /* The extra dword is used to avoid LDS bank conflicts. */
647 unsigned vertex_size = ngg_nogs_vertex_size(ctx->shader);
648 LLVMTypeRef ai32 = LLVMArrayType(ctx->ac.i32, vertex_size);
649 LLVMTypeRef pai32 = LLVMPointerType(ai32, AC_ADDR_SPACE_LDS);
650 LLVMValueRef tmp = LLVMBuildBitCast(ctx->ac.builder, ctx->esgs_ring, pai32, "");
651 return LLVMBuildGEP(ctx->ac.builder, tmp, &vtxid, 1, "");
652 }
653
si_insert_input_v4i32(struct si_shader_context * ctx,LLVMValueRef ret,struct ac_arg param,unsigned return_index)654 static LLVMValueRef si_insert_input_v4i32(struct si_shader_context *ctx, LLVMValueRef ret,
655 struct ac_arg param, unsigned return_index)
656 {
657 LLVMValueRef v = ac_get_arg(&ctx->ac, param);
658
659 for (unsigned i = 0; i < 4; i++) {
660 ret = LLVMBuildInsertValue(ctx->ac.builder, ret, ac_llvm_extract_elem(&ctx->ac, v, i),
661 return_index + i, "");
662 }
663 return ret;
664 }
665
load_vertex_counts(struct si_shader_context * ctx,LLVMValueRef lds,unsigned max_waves,LLVMValueRef tid,LLVMValueRef * total_count,LLVMValueRef * prefix_sum)666 static void load_vertex_counts(struct si_shader_context *ctx, LLVMValueRef lds,
667 unsigned max_waves, LLVMValueRef tid,
668 LLVMValueRef *total_count,
669 LLVMValueRef *prefix_sum)
670 {
671 LLVMBuilderRef builder = ctx->ac.builder;
672 LLVMValueRef i8vec4_lane = ac_build_alloca_undef(&ctx->ac, ctx->ac.i32, "");
673 unsigned num_i8vec4 = DIV_ROUND_UP(max_waves, 4);
674
675 /* If all threads loaded the vertex counts, it would cause many LDS bank conflicts
676 * and the performance could decrease up to WaveSize times (32x or 64x).
677 *
678 * Therefore, only load the i-th tuple of vertex counts in the i-th thread. Other threads will
679 * get them through readlane. 4 8-bit vertex counts are loaded per thread.
680 */
681 ac_build_ifcc(&ctx->ac, LLVMBuildICmp(builder, LLVMIntULT, tid,
682 LLVMConstInt(ctx->ac.i32, num_i8vec4, 0), ""), 17771);
683 LLVMBuildStore(builder, LLVMBuildLoad(builder, ac_build_gep0(&ctx->ac, lds, tid), ""), i8vec4_lane);
684 ac_build_endif(&ctx->ac, 17771);
685
686 /* Compute the number of ES waves. */
687 LLVMValueRef num_waves = get_tgsize(ctx);
688
689 /* Compute a byte mask where each byte is either 0 or 0xff depending on whether the wave
690 * exists. We need the mask to clear uninitialized bytes in LDS and to compute the prefix sum.
691 *
692 * 8 waves: valid_mask = ~0ull >> (64 - num_waves * 8)
693 * 4 waves: valid_mask = ~0 >> (32 - num_waves * 8)
694 */
695 LLVMValueRef num_waves8 = LLVMBuildShl(builder, num_waves, LLVMConstInt(ctx->ac.i32, 3, 0), "");
696 LLVMValueRef valid_mask;
697
698 if (max_waves > 4) {
699 LLVMValueRef num_waves8_rev = LLVMBuildSub(builder, LLVMConstInt(ctx->ac.i32, 64, 0),
700 num_waves8, "");
701 valid_mask = LLVMBuildLShr(builder, LLVMConstInt(ctx->ac.i64, ~0ull, 0),
702 LLVMBuildZExt(builder, num_waves8_rev, ctx->ac.i64, ""), "");
703 } else {
704 LLVMValueRef num_waves8_rev = LLVMBuildSub(builder, LLVMConstInt(ctx->ac.i32, 32, 0),
705 num_waves8, "");
706 valid_mask = LLVMBuildLShr(builder, LLVMConstInt(ctx->ac.i32, ~0, 0), num_waves8_rev, "");
707 }
708
709 /* Compute a byte mask where bytes below wave_id are 0xff, else they are 0.
710 *
711 * prefix_mask = ~(~0 << (wave_id * 8))
712 */
713 LLVMTypeRef type = max_waves > 4 ? ctx->ac.i64 : ctx->ac.i32;
714 LLVMValueRef wave_id8 = LLVMBuildShl(builder, get_wave_id_in_tg(ctx),
715 LLVMConstInt(ctx->ac.i32, 3, 0), "");
716 LLVMValueRef prefix_mask =
717 LLVMBuildNot(builder, LLVMBuildShl(builder, LLVMConstInt(type, ~0ull, 0),
718 LLVMBuildZExt(builder, wave_id8, type, ""), ""), "");
719
720 /* Compute the total vertex count and the vertex count of previous waves (prefix). */
721 *total_count = ctx->ac.i32_0;
722 *prefix_sum = ctx->ac.i32_0;
723
724 for (unsigned i = 0; i < num_i8vec4; i++) {
725 LLVMValueRef i8vec4;
726
727 i8vec4 = ac_build_readlane_no_opt_barrier(&ctx->ac, LLVMBuildLoad(builder, i8vec4_lane, ""),
728 LLVMConstInt(ctx->ac.i32, i, 0));
729 /* Inactive waves have uninitialized vertex counts. Set them to 0 using this. */
730 i8vec4 = LLVMBuildAnd(builder, i8vec4,
731 ac_unpack_param(&ctx->ac, valid_mask, 32 * i, 32), "");
732 /* Compute the sum of all i8vec4 components and add it to the result. */
733 *total_count = ac_build_intrinsic(&ctx->ac, "llvm.amdgcn.sad.u8", ctx->ac.i32,
734 (LLVMValueRef[]){i8vec4, ctx->ac.i32_0, *total_count},
735 3, AC_FUNC_ATTR_READNONE);
736 ac_set_range_metadata(&ctx->ac, *total_count, 0, 64*4 + 1); /* the result is at most 64*4 */
737
738 /* Compute the sum of the vertex counts of all previous waves. */
739 i8vec4 = LLVMBuildAnd(builder, i8vec4,
740 ac_unpack_param(&ctx->ac, prefix_mask, 32 * i, 32), "");
741 *prefix_sum = ac_build_intrinsic(&ctx->ac, "llvm.amdgcn.sad.u8", ctx->ac.i32,
742 (LLVMValueRef[]){i8vec4, ctx->ac.i32_0, *prefix_sum},
743 3, AC_FUNC_ATTR_READNONE);
744 ac_set_range_metadata(&ctx->ac, *prefix_sum, 0, 64*4 + 1); /* the result is at most 64*4 */
745 }
746 *total_count = ac_build_readlane_no_opt_barrier(&ctx->ac, *total_count, NULL);
747 }
748
749 /**
750 * Given a total thread count, update total and per-wave thread counts in input SGPRs
751 * and return the per-wave thread count.
752 *
753 * \param new_num_threads Total thread count on the input, per-wave thread count on the output.
754 * \param tg_info tg_info SGPR value
755 * \param tg_info_num_bits the bit size of thread count field in tg_info
756 * \param tg_info_shift the bit offset of the thread count field in tg_info
757 * \param wave_info merged_wave_info SGPR value
758 * \param wave_info_num_bits the bit size of thread count field in merged_wave_info
759 * \param wave_info_shift the bit offset of the thread count field in merged_wave_info
760 */
update_thread_counts(struct si_shader_context * ctx,LLVMValueRef * new_num_threads,LLVMValueRef * tg_info,unsigned tg_info_num_bits,unsigned tg_info_shift,LLVMValueRef * wave_info,unsigned wave_info_num_bits,unsigned wave_info_shift)761 static void update_thread_counts(struct si_shader_context *ctx, LLVMValueRef *new_num_threads,
762 LLVMValueRef *tg_info, unsigned tg_info_num_bits,
763 unsigned tg_info_shift, LLVMValueRef *wave_info,
764 unsigned wave_info_num_bits, unsigned wave_info_shift)
765 {
766 LLVMBuilderRef builder = ctx->ac.builder;
767
768 /* Update the total thread count. */
769 unsigned tg_info_mask = ~(u_bit_consecutive(0, tg_info_num_bits) << tg_info_shift);
770 *tg_info = LLVMBuildAnd(builder, *tg_info, LLVMConstInt(ctx->ac.i32, tg_info_mask, 0), "");
771 *tg_info = LLVMBuildOr(
772 builder, *tg_info,
773 LLVMBuildShl(builder, *new_num_threads, LLVMConstInt(ctx->ac.i32, tg_info_shift, 0), ""), "");
774
775 /* Update the per-wave thread count. */
776 LLVMValueRef prev_threads = LLVMBuildMul(builder, get_wave_id_in_tg(ctx),
777 LLVMConstInt(ctx->ac.i32, ctx->ac.wave_size, 0), "");
778 *new_num_threads = LLVMBuildSub(builder, *new_num_threads, prev_threads, "");
779 *new_num_threads = ac_build_imax(&ctx->ac, *new_num_threads, ctx->ac.i32_0);
780 *new_num_threads =
781 ac_build_imin(&ctx->ac, *new_num_threads, LLVMConstInt(ctx->ac.i32, ctx->ac.wave_size, 0));
782 unsigned wave_info_mask = ~(u_bit_consecutive(0, wave_info_num_bits) << wave_info_shift);
783 *wave_info = LLVMBuildAnd(builder, *wave_info, LLVMConstInt(ctx->ac.i32, wave_info_mask, 0), "");
784 *wave_info = LLVMBuildOr(
785 builder, *wave_info,
786 LLVMBuildShl(builder, *new_num_threads, LLVMConstInt(ctx->ac.i32, wave_info_shift, 0), ""),
787 "");
788 }
789
gfx10_build_primitive_accepted(struct ac_llvm_context * ac,LLVMValueRef accepted,void * userdata)790 static void gfx10_build_primitive_accepted(struct ac_llvm_context *ac, LLVMValueRef accepted,
791 void *userdata)
792 {
793 struct si_shader_context *ctx = container_of(ac, struct si_shader_context, ac);
794 LLVMValueRef *params = (LLVMValueRef *)userdata;
795 LLVMValueRef gs_accepted = params[0];
796 LLVMValueRef *gs_vtxptr = (LLVMValueRef *)params[1];
797
798 unsigned num_vertices;
799 ngg_get_vertices_per_prim(ctx, &num_vertices);
800
801 ac_build_ifcc(&ctx->ac, accepted, 0);
802 LLVMBuildStore(ctx->ac.builder, ctx->ac.i32_1, gs_accepted);
803 for (unsigned vtx = 0; vtx < num_vertices; vtx++) {
804 LLVMBuildStore(ctx->ac.builder, ctx->ac.i8_1,
805 si_build_gep_i8(ctx, gs_vtxptr[vtx], lds_byte0_accept_flag));
806 }
807 ac_build_endif(&ctx->ac, 0);
808 }
809
810 /**
811 * Cull primitives for NGG VS or TES, then compact vertices, which happens
812 * before the VS or TES main function. Return values for the main function.
813 * Also return the position, which is passed to the shader as an input,
814 * so that we don't compute it twice.
815 */
gfx10_emit_ngg_culling_epilogue(struct ac_shader_abi * abi)816 void gfx10_emit_ngg_culling_epilogue(struct ac_shader_abi *abi)
817 {
818 struct si_shader_context *ctx = si_shader_context_from_abi(abi);
819 struct si_shader *shader = ctx->shader;
820 struct si_shader_selector *sel = shader->selector;
821 struct si_shader_info *info = &sel->info;
822 LLVMBuilderRef builder = ctx->ac.builder;
823 LLVMValueRef *addrs = abi->outputs;
824 unsigned max_waves = DIV_ROUND_UP(ctx->screen->ngg_subgroup_size, ctx->ac.wave_size);
825
826 assert(shader->key.opt.ngg_culling);
827 assert(shader->key.as_ngg);
828 assert(sel->info.stage == MESA_SHADER_VERTEX ||
829 (sel->info.stage == MESA_SHADER_TESS_EVAL && !shader->key.as_es));
830
831 LLVMValueRef es_vtxptr = ngg_nogs_vertex_ptr(ctx, get_thread_id_in_tg(ctx));
832 unsigned pos_index = 0;
833
834 for (unsigned i = 0; i < info->num_outputs; i++) {
835 LLVMValueRef position[4];
836
837 switch (info->output_semantic[i]) {
838 case VARYING_SLOT_POS:
839 /* If we are going to cull everything (rasterizer_discard), discard
840 * the position. This is useful for analyzing maximum theoretical
841 * performance without VS input loads.
842 */
843 if (shader->key.opt.ngg_culling & SI_NGG_CULL_FRONT_FACE &&
844 shader->key.opt.ngg_culling & SI_NGG_CULL_BACK_FACE) {
845 for (unsigned j = 0; j < 4; j++)
846 LLVMBuildStore(builder, LLVMGetUndef(ctx->ac.f32), addrs[4 * i + j]);
847 break;
848 }
849
850 pos_index = i;
851 for (unsigned j = 0; j < 4; j++) {
852 position[j] = LLVMBuildLoad(ctx->ac.builder, addrs[4 * i + j], "");
853 }
854
855 /* Store Position.W into LDS. */
856 LLVMBuildStore(
857 builder, ac_to_integer(&ctx->ac, position[3]),
858 ac_build_gep0(&ctx->ac, es_vtxptr, LLVMConstInt(ctx->ac.i32, lds_pos_cull_w, 0)));
859
860 /* Store Position.XY / W into LDS. */
861 for (unsigned chan = 0; chan < 2; chan++) {
862 LLVMValueRef val = ac_build_fdiv(&ctx->ac, position[chan], position[3]);
863 LLVMBuildStore(
864 builder, ac_to_integer(&ctx->ac, val),
865 ac_build_gep0(&ctx->ac, es_vtxptr, LLVMConstInt(ctx->ac.i32, lds_pos_cull_x_div_w + chan, 0)));
866 }
867 break;
868 }
869 }
870
871 /* Initialize the packed data. */
872 LLVMBuildStore(
873 builder, ctx->ac.i32_0,
874 ac_build_gep0(&ctx->ac, es_vtxptr, LLVMConstInt(ctx->ac.i32, lds_packed_data, 0)));
875 ac_build_endif(&ctx->ac, ctx->merged_wrap_if_label);
876 ac_build_s_barrier(&ctx->ac);
877
878 LLVMValueRef tid = ac_get_thread_id(&ctx->ac);
879
880 unsigned num_vertices;
881 ngg_get_vertices_per_prim(ctx, &num_vertices);
882
883 /* The hardware requires that there are no holes between unculled vertices,
884 * which means we have to pack ES threads, i.e. reduce the ES thread count
885 * and move ES input VGPRs to lower threads. The upside is that varyings
886 * are only fetched and computed for unculled vertices.
887 *
888 * Vertex compaction:
889 *
890 * Part 1: Store the surviving vertex count for each wave in LDS.
891 * - The GS culling code notifies ES threads which vertices were accepted.
892 * - Barrier
893 * - ES threads will compute the vertex count and store it in LDS.
894 * - Barrier
895 * - Each wave loads the vertex counts from LDS.
896 *
897 * Part 2: Compact ES threads:
898 * - Compute the prefix sum for each surviving vertex. This is the new thread ID
899 * of the vertex.
900 * - Write input VGPRs and vertex positions for each surviving vertex into the LDS
901 * address of the new thread ID.
902 * - Now kill all waves that have inactive threads.
903 * - Barrier
904 * - Update vertex indices and null flag in the GS input VGPRs.
905 *
906 * Part 3: Update inputs GPRs
907 * - For all waves, update per-wave thread counts in input SGPRs.
908 * - In ES threads, update the ES input VGPRs (VertexID, InstanceID, TES inputs).
909 */
910
911 LLVMValueRef vtxindex[3];
912 for (unsigned i = 0; i < num_vertices; ++i)
913 vtxindex[i] = si_unpack_param(ctx, ctx->args.gs_vtx_offset[i / 2], (i & 1) * 16, 16);
914
915 LLVMValueRef gs_vtxptr[3];
916 for (unsigned i = 0; i < num_vertices; i++)
917 gs_vtxptr[i] = ngg_nogs_vertex_ptr(ctx, vtxindex[i]);
918
919 es_vtxptr = ngg_nogs_vertex_ptr(ctx, get_thread_id_in_tg(ctx));
920
921 /* Adding these optimization barriers improves the generated code as follows. Crazy right?
922 *
923 * - s_mov_b32 s4, 0xffff
924 * - v_lshrrev_b32_e32 v10, 16, v0
925 * - v_and_b32_e32 v12, s4, v0
926 * - v_and_b32_e32 v11, s4, v1
927 * s_bfe_u32 s4, s3, 0x80008
928 * - s_mov_b64 s[8:9], 0
929 * - v_mul_u32_u24_e32 v0, 28, v10
930 * - v_mul_u32_u24_e32 v9, 28, v12
931 * - v_mul_u32_u24_e32 v1, 28, v11
932 * + v_mov_b32_e32 v11, 28
933 * v_cmp_gt_u32_e32 vcc, s4, v2
934 * + s_mov_b64 s[8:9], 0
935 * s_waitcnt lgkmcnt(0)
936 * s_barrier
937 * + v_mul_u32_u24_sdwa v10, v0, v11 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0 src1_sel:DWORD
938 * + v_mul_u32_u24_sdwa v23, v0, v11 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1 src1_sel:DWORD
939 * + v_mul_u32_u24_sdwa v0, v1, v11 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0 src1_sel:DWORD
940 * s_and_saveexec_b64 s[44:45], vcc
941 * s_cbranch_execz BB2_8
942 * - v_mul_u32_u24_e32 v16, 28, v12
943 * - v_mul_u32_u24_e32 v17, 28, v11
944 * - v_mul_u32_u24_e32 v18, 28, v10
945 */
946 for (unsigned i = 0; i < num_vertices; i++)
947 ac_build_optimization_barrier(&ctx->ac, &gs_vtxptr[i], false);
948
949 LLVMValueRef gs_accepted = ac_build_alloca(&ctx->ac, ctx->ac.i32, "");
950
951 /* Do culling in GS threads. */
952 ac_build_ifcc(&ctx->ac, si_is_gs_thread(ctx), 16002);
953 {
954 /* Load positions. */
955 LLVMValueRef pos[3][4] = {};
956 for (unsigned vtx = 0; vtx < num_vertices; vtx++) {
957 for (unsigned chan = 0; chan < 4; chan++) {
958 unsigned index;
959 if (chan == 0 || chan == 1)
960 index = lds_pos_cull_x_div_w + chan;
961 else if (chan == 3)
962 index = lds_pos_cull_w;
963 else
964 continue;
965
966 LLVMValueRef addr =
967 ac_build_gep0(&ctx->ac, gs_vtxptr[vtx], LLVMConstInt(ctx->ac.i32, index, 0));
968 pos[vtx][chan] = LLVMBuildLoad(builder, addr, "");
969 pos[vtx][chan] = ac_to_float(&ctx->ac, pos[vtx][chan]);
970 }
971 }
972
973 /* Load the viewport state for small prim culling. */
974 LLVMValueRef vp = ac_build_load_invariant(
975 &ctx->ac, ac_get_arg(&ctx->ac, ctx->small_prim_cull_info), ctx->ac.i32_0);
976 vp = LLVMBuildBitCast(builder, vp, ctx->ac.v4f32, "");
977 LLVMValueRef vp_scale[2], vp_translate[2];
978 vp_scale[0] = ac_llvm_extract_elem(&ctx->ac, vp, 0);
979 vp_scale[1] = ac_llvm_extract_elem(&ctx->ac, vp, 1);
980 vp_translate[0] = ac_llvm_extract_elem(&ctx->ac, vp, 2);
981 vp_translate[1] = ac_llvm_extract_elem(&ctx->ac, vp, 3);
982
983 /* Get the small prim filter precision. */
984 LLVMValueRef small_prim_precision = si_unpack_param(ctx, ctx->vs_state_bits, 7, 4);
985 small_prim_precision =
986 LLVMBuildOr(builder, small_prim_precision, LLVMConstInt(ctx->ac.i32, 0x70, 0), "");
987 small_prim_precision =
988 LLVMBuildShl(builder, small_prim_precision, LLVMConstInt(ctx->ac.i32, 23, 0), "");
989 small_prim_precision = LLVMBuildBitCast(builder, small_prim_precision, ctx->ac.f32, "");
990
991 /* Execute culling code. */
992 struct ac_cull_options options = {};
993 options.cull_view_xy = true;
994 options.cull_w = true;
995
996 if (shader->key.opt.ngg_culling & SI_NGG_CULL_LINES) {
997 options.num_vertices = 2;
998
999 assert(!(shader->key.opt.ngg_culling & SI_NGG_CULL_BACK_FACE));
1000 assert(!(shader->key.opt.ngg_culling & SI_NGG_CULL_FRONT_FACE));
1001 } else {
1002 options.num_vertices = 3;
1003 options.cull_front = shader->key.opt.ngg_culling & SI_NGG_CULL_FRONT_FACE;
1004 options.cull_back = shader->key.opt.ngg_culling & SI_NGG_CULL_BACK_FACE;
1005 options.cull_small_prims = true; /* this would only be false with conservative rasterization */
1006 options.cull_zero_area = options.cull_front || options.cull_back;
1007 }
1008
1009 /* Tell ES threads whether their vertex survived. */
1010 LLVMValueRef params[] = {
1011 gs_accepted,
1012 (void*)gs_vtxptr,
1013 };
1014 ac_cull_primitive(&ctx->ac, pos, ctx->ac.i1true, vp_scale, vp_translate,
1015 small_prim_precision, &options,
1016 gfx10_build_primitive_accepted, params);
1017 }
1018 ac_build_endif(&ctx->ac, 16002);
1019 ac_build_s_barrier(&ctx->ac);
1020
1021 gs_accepted = LLVMBuildLoad(builder, gs_accepted, "");
1022
1023 LLVMValueRef vertex_accepted = ac_build_alloca(&ctx->ac, ctx->ac.i1, "");
1024 LLVMValueRef vertex_mask = ac_build_alloca(&ctx->ac, ctx->ac.iN_wavemask, "");
1025
1026 /* Convert the per-vertex accept flag to a vertex thread mask, store it in registers. */
1027 ac_build_ifcc(&ctx->ac, si_is_es_thread(ctx), 16007);
1028 {
1029 LLVMValueRef accepted =
1030 LLVMBuildLoad(builder, si_build_gep_i8(ctx, es_vtxptr, lds_byte0_accept_flag), "");
1031 accepted = LLVMBuildICmp(builder, LLVMIntNE, accepted, ctx->ac.i8_0, "");
1032 LLVMValueRef mask = ac_get_i1_sgpr_mask(&ctx->ac, accepted);
1033
1034 LLVMBuildStore(builder, accepted, vertex_accepted);
1035 LLVMBuildStore(builder, mask, vertex_mask);
1036 }
1037 ac_build_endif(&ctx->ac, 16007);
1038
1039 /* Store the per-wave vertex count to LDS. Non-ES waves store 0. */
1040 vertex_mask = LLVMBuildLoad(builder, vertex_mask, "");
1041 ac_build_ifcc(&ctx->ac, LLVMBuildICmp(builder, LLVMIntEQ, tid, ctx->ac.i32_0, ""), 16008);
1042 {
1043 LLVMValueRef vertex_count = ac_build_bit_count(&ctx->ac, vertex_mask);
1044 LLVMBuildStore(builder, LLVMBuildTrunc(builder, vertex_count, ctx->ac.i8, ""),
1045 si_build_gep_i8_var(ctx, ctx->gs_ngg_scratch, get_wave_id_in_tg(ctx)));
1046 }
1047 ac_build_endif(&ctx->ac, 16008);
1048
1049 ac_build_s_barrier(&ctx->ac);
1050
1051 /* Load the vertex masks and compute the new ES thread count. */
1052 LLVMValueRef new_num_es_threads, prefix_sum, kill_wave;
1053 load_vertex_counts(ctx, ctx->gs_ngg_scratch, max_waves, tid, &new_num_es_threads,
1054 &prefix_sum);
1055
1056 bool uses_instance_id = ctx->stage == MESA_SHADER_VERTEX &&
1057 (sel->info.uses_instanceid ||
1058 shader->key.part.vs.prolog.instance_divisor_is_one ||
1059 shader->key.part.vs.prolog.instance_divisor_is_fetched);
1060 bool uses_tes_prim_id = ctx->stage == MESA_SHADER_TESS_EVAL &&
1061 (sel->info.uses_primid || shader->key.mono.u.vs_export_prim_id);
1062
1063 /* ES threads compute their prefix sum, which is the new ES thread ID.
1064 * Then they write the vertex position and input VGPRs into the LDS address
1065 * of the new thread ID. It will be used to load input VGPRs by compacted
1066 * threads.
1067 */
1068 vertex_accepted = LLVMBuildLoad(builder, vertex_accepted, "");
1069 ac_build_ifcc(&ctx->ac, vertex_accepted, 16009);
1070 {
1071 /* Add the number of bits set in vertex_mask up to the current thread ID - 1
1072 * to get the prefix sum.
1073 */
1074 prefix_sum = LLVMBuildAdd(builder, prefix_sum, ac_build_mbcnt(&ctx->ac, vertex_mask), "");
1075
1076 LLVMValueRef new_id = prefix_sum;
1077 LLVMValueRef new_vtx = ngg_nogs_vertex_ptr(ctx, new_id);
1078
1079 LLVMBuildStore(builder, LLVMBuildTrunc(builder, new_id, ctx->ac.i8, ""),
1080 si_build_gep_i8(ctx, es_vtxptr, lds_byte1_new_thread_id));
1081
1082 /* Store Position.XYZW into LDS. */
1083 for (unsigned chan = 0; chan < 4; chan++) {
1084 LLVMBuildStore(
1085 builder, ac_to_integer(&ctx->ac, LLVMBuildLoad(builder, addrs[4 * pos_index + chan], "")),
1086 ac_build_gep0(&ctx->ac, new_vtx, LLVMConstInt(ctx->ac.i32, lds_pos_x + chan, 0)));
1087 }
1088
1089 /* Store VertexID and InstanceID into LDS. ES threads will have to load them
1090 * from LDS after vertex compaction and use them instead of their own
1091 * system values.
1092 */
1093 if (ctx->stage == MESA_SHADER_VERTEX) {
1094 LLVMBuildStore(
1095 builder, ctx->abi.vertex_id,
1096 ac_build_gep0(&ctx->ac, new_vtx, LLVMConstInt(ctx->ac.i32, lds_vertex_id, 0)));
1097 if (uses_instance_id) {
1098 LLVMBuildStore(
1099 builder, ctx->abi.instance_id,
1100 ac_build_gep0(&ctx->ac, new_vtx, LLVMConstInt(ctx->ac.i32, lds_instance_id, 0)));
1101 }
1102 } else {
1103 assert(ctx->stage == MESA_SHADER_TESS_EVAL);
1104 LLVMBuildStore(builder, ac_to_integer(&ctx->ac, ac_get_arg(&ctx->ac, ctx->args.tes_u)),
1105 ac_build_gep0(&ctx->ac, new_vtx, LLVMConstInt(ctx->ac.i32, lds_tes_u, 0)));
1106 LLVMBuildStore(builder, ac_to_integer(&ctx->ac, ac_get_arg(&ctx->ac, ctx->args.tes_v)),
1107 ac_build_gep0(&ctx->ac, new_vtx, LLVMConstInt(ctx->ac.i32, lds_tes_v, 0)));
1108 LLVMBuildStore(builder, LLVMBuildTrunc(builder, ac_get_arg(&ctx->ac, ctx->args.tes_rel_patch_id), ctx->ac.i8, ""),
1109 si_build_gep_i8(ctx, new_vtx, lds_byte2_tes_rel_patch_id));
1110 if (uses_tes_prim_id) {
1111 LLVMBuildStore(
1112 builder, ac_get_arg(&ctx->ac, ctx->args.tes_patch_id),
1113 ac_build_gep0(&ctx->ac, new_vtx, LLVMConstInt(ctx->ac.i32, lds_tes_patch_id, 0)));
1114 }
1115 }
1116 }
1117 ac_build_endif(&ctx->ac, 16009);
1118
1119 /* If all vertices are culled, set the primitive count to 0, so that all waves are culled here. */
1120 LLVMValueRef num_primitives = ngg_get_prim_cnt(ctx);
1121 num_primitives = LLVMBuildSelect(builder,
1122 LLVMBuildICmp(builder, LLVMIntEQ, new_num_es_threads,
1123 ctx->ac.i32_0, ""),
1124 ctx->ac.i32_0, num_primitives, "");
1125 /* Kill waves that have inactive threads. */
1126 kill_wave = LLVMBuildICmp(builder, LLVMIntULE,
1127 ac_build_imax(&ctx->ac, new_num_es_threads, num_primitives),
1128 LLVMBuildMul(builder, get_wave_id_in_tg(ctx),
1129 LLVMConstInt(ctx->ac.i32, ctx->ac.wave_size, 0), ""),
1130 "");
1131 ac_build_ifcc(&ctx->ac, kill_wave, 19202);
1132 {
1133 /* If we are killing wave 0, send that there are no primitives
1134 * in this threadgroup.
1135 */
1136 ac_build_sendmsg_gs_alloc_req(&ctx->ac, get_wave_id_in_tg(ctx), ctx->ac.i32_0, ctx->ac.i32_0);
1137 ac_build_s_endpgm(&ctx->ac);
1138 }
1139 ac_build_endif(&ctx->ac, 19202);
1140 ac_build_s_barrier(&ctx->ac);
1141
1142 /* Send the final vertex and primitive counts. */
1143 ac_build_sendmsg_gs_alloc_req(&ctx->ac, get_wave_id_in_tg(ctx), new_num_es_threads,
1144 ngg_get_prim_cnt(ctx));
1145
1146 /* Update thread counts in SGPRs. */
1147 LLVMValueRef new_gs_tg_info = ac_get_arg(&ctx->ac, ctx->args.gs_tg_info);
1148 LLVMValueRef new_merged_wave_info = ac_get_arg(&ctx->ac, ctx->args.merged_wave_info);
1149
1150 /* This also converts the thread count from the total count to the per-wave count. */
1151 update_thread_counts(ctx, &new_num_es_threads, &new_gs_tg_info, 9, 12, &new_merged_wave_info, 8,
1152 0);
1153
1154 /* Update vertex indices in VGPR0 (same format as NGG passthrough).
1155 *
1156 * Set the null flag at the beginning (culled), and then
1157 * overwrite it for accepted primitives.
1158 */
1159 LLVMValueRef new_vgpr0 =
1160 ac_build_alloca_init(&ctx->ac, LLVMConstInt(ctx->ac.i32, 1u << 31, 0), "");
1161
1162 /* Get vertex indices after vertex compaction. */
1163 ac_build_ifcc(&ctx->ac, LLVMBuildTrunc(builder, gs_accepted, ctx->ac.i1, ""), 16011);
1164 {
1165 struct ac_ngg_prim prim = {};
1166 prim.num_vertices = num_vertices;
1167 prim.isnull = ctx->ac.i1false;
1168
1169 if (gfx10_edgeflags_have_effect(shader))
1170 prim.edgeflags = ac_pack_edgeflags_for_export(&ctx->ac, &ctx->args);
1171 else
1172 prim.edgeflags = ctx->ac.i32_0;
1173
1174 for (unsigned vtx = 0; vtx < num_vertices; vtx++) {
1175 prim.index[vtx] = LLVMBuildLoad(
1176 builder, si_build_gep_i8(ctx, gs_vtxptr[vtx], lds_byte1_new_thread_id), "");
1177 prim.index[vtx] = LLVMBuildZExt(builder, prim.index[vtx], ctx->ac.i32, "");
1178 }
1179
1180 /* Set the new GS input VGPR. */
1181 LLVMBuildStore(builder, ac_pack_prim_export(&ctx->ac, &prim), new_vgpr0);
1182 }
1183 ac_build_endif(&ctx->ac, 16011);
1184
1185 if (gfx10_ngg_export_prim_early(shader))
1186 gfx10_ngg_build_export_prim(ctx, NULL, LLVMBuildLoad(builder, new_vgpr0, ""));
1187
1188 /* Prepare LDS addresses of the new ES input VGPRs. */
1189 LLVMValueRef input_vgpr_addresses[4] = {
1190 ac_build_gep0(&ctx->ac, es_vtxptr, LLVMConstInt(ctx->ac.i32, lds_vertex_id, 0)),
1191 ac_build_gep0(&ctx->ac, es_vtxptr, LLVMConstInt(ctx->ac.i32, lds_instance_id, 0)),
1192 };
1193 if (ctx->stage == MESA_SHADER_TESS_EVAL) {
1194 input_vgpr_addresses[2] = si_build_gep_i8(ctx, es_vtxptr, lds_byte2_tes_rel_patch_id);
1195 if (uses_tes_prim_id) {
1196 input_vgpr_addresses[3] = ac_build_gep0(&ctx->ac, es_vtxptr,
1197 LLVMConstInt(ctx->ac.i32, lds_tes_patch_id, 0));
1198 }
1199 }
1200
1201 /* Return values for the main function. */
1202 LLVMValueRef ret = ctx->return_value;
1203 LLVMValueRef val;
1204
1205 ret = LLVMBuildInsertValue(ctx->ac.builder, ret, new_gs_tg_info, 2, "");
1206 ret = LLVMBuildInsertValue(ctx->ac.builder, ret, new_merged_wave_info, 3, "");
1207 if (ctx->stage == MESA_SHADER_TESS_EVAL)
1208 ret = si_insert_input_ret(ctx, ret, ctx->args.tess_offchip_offset, 4);
1209
1210 ret = si_insert_input_ptr(ctx, ret, ctx->internal_bindings, 8 + SI_SGPR_INTERNAL_BINDINGS);
1211 ret = si_insert_input_ptr(ctx, ret, ctx->bindless_samplers_and_images,
1212 8 + SI_SGPR_BINDLESS_SAMPLERS_AND_IMAGES);
1213 ret = si_insert_input_ptr(ctx, ret, ctx->const_and_shader_buffers,
1214 8 + SI_SGPR_CONST_AND_SHADER_BUFFERS);
1215 ret = si_insert_input_ptr(ctx, ret, ctx->samplers_and_images, 8 + SI_SGPR_SAMPLERS_AND_IMAGES);
1216 ret = si_insert_input_ptr(ctx, ret, ctx->vs_state_bits, 8 + SI_SGPR_VS_STATE_BITS);
1217
1218 if (ctx->stage == MESA_SHADER_VERTEX) {
1219 ret = si_insert_input_ptr(ctx, ret, ctx->args.base_vertex, 8 + SI_SGPR_BASE_VERTEX);
1220 ret = si_insert_input_ptr(ctx, ret, ctx->args.draw_id, 8 + SI_SGPR_DRAWID);
1221 ret = si_insert_input_ptr(ctx, ret, ctx->args.start_instance, 8 + SI_SGPR_START_INSTANCE);
1222 ret = si_insert_input_ptr(ctx, ret, ctx->args.vertex_buffers, 8 + SI_VS_NUM_USER_SGPR);
1223
1224 for (unsigned i = 0; i < shader->selector->num_vbos_in_user_sgprs; i++) {
1225 ret = si_insert_input_v4i32(ctx, ret, ctx->vb_descriptors[i],
1226 8 + SI_SGPR_VS_VB_DESCRIPTOR_FIRST + i * 4);
1227 }
1228 } else {
1229 assert(ctx->stage == MESA_SHADER_TESS_EVAL);
1230 ret = si_insert_input_ptr(ctx, ret, ctx->tcs_offchip_layout, 8 + SI_SGPR_TES_OFFCHIP_LAYOUT);
1231 ret = si_insert_input_ptr(ctx, ret, ctx->tes_offchip_addr, 8 + SI_SGPR_TES_OFFCHIP_ADDR);
1232 }
1233
1234 unsigned vgpr;
1235 if (ctx->stage == MESA_SHADER_VERTEX) {
1236 if (shader->selector->num_vbos_in_user_sgprs) {
1237 vgpr = 8 + SI_SGPR_VS_VB_DESCRIPTOR_FIRST + shader->selector->num_vbos_in_user_sgprs * 4;
1238 } else {
1239 vgpr = 8 + GFX9_VSGS_NUM_USER_SGPR + 1;
1240 }
1241 } else {
1242 vgpr = 8 + GFX9_TESGS_NUM_USER_SGPR;
1243 }
1244
1245 val = LLVMBuildLoad(builder, new_vgpr0, "");
1246 ret = LLVMBuildInsertValue(builder, ret, ac_to_float(&ctx->ac, val), vgpr++, "");
1247 vgpr++; /* gs_vtx_offset[1] = offsets of vertices 2-3 */
1248
1249 ret = si_insert_input_ret_float(ctx, ret, ctx->args.gs_prim_id, vgpr++);
1250 ret = si_insert_input_ret_float(ctx, ret, ctx->args.gs_invocation_id, vgpr++);
1251 vgpr++; /* gs_vtx_offset[2] = offsets of vertices 4-5 */
1252
1253 /* Set the input VPGRs to the corresponding LDS addresses where the VGPR values are
1254 * stored. The VS prolog will load them.
1255 */
1256 if (ctx->stage == MESA_SHADER_VERTEX) {
1257 val = LLVMBuildPtrToInt(builder, input_vgpr_addresses[0], ctx->ac.i32, "");
1258 ret = LLVMBuildInsertValue(builder, ret, ac_to_float(&ctx->ac, val), vgpr++,
1259 ""); /* VGPR5 - VertexID */
1260 vgpr += 2;
1261 if (uses_instance_id) {
1262 val = LLVMBuildPtrToInt(builder, input_vgpr_addresses[1], ctx->ac.i32, "");
1263 ret = LLVMBuildInsertValue(builder, ret, ac_to_float(&ctx->ac, val), vgpr++,
1264 ""); /* VGPR8 - InstanceID */
1265 } else {
1266 vgpr++;
1267 }
1268 } else {
1269 assert(ctx->stage == MESA_SHADER_TESS_EVAL);
1270 unsigned num_vgprs = uses_tes_prim_id ? 4 : 3;
1271 for (unsigned i = 0; i < num_vgprs; i++) {
1272 val = LLVMBuildPtrToInt(builder, input_vgpr_addresses[i], ctx->ac.i32, "");
1273 ret = LLVMBuildInsertValue(builder, ret, ac_to_float(&ctx->ac, val), vgpr++, "");
1274 }
1275 if (num_vgprs == 3)
1276 vgpr++;
1277 }
1278
1279 /* These two also use LDS. */
1280 if (gfx10_ngg_writes_user_edgeflags(shader) ||
1281 (ctx->stage == MESA_SHADER_VERTEX && shader->key.mono.u.vs_export_prim_id))
1282 ac_build_s_barrier(&ctx->ac);
1283
1284 ctx->return_value = ret;
1285 }
1286
1287 /**
1288 * Emit the epilogue of an API VS or TES shader compiled as ESGS shader.
1289 */
gfx10_emit_ngg_epilogue(struct ac_shader_abi * abi)1290 void gfx10_emit_ngg_epilogue(struct ac_shader_abi *abi)
1291 {
1292 struct si_shader_context *ctx = si_shader_context_from_abi(abi);
1293 struct si_shader_selector *sel = ctx->shader->selector;
1294 struct si_shader_info *info = &sel->info;
1295 struct si_shader_output_values outputs[PIPE_MAX_SHADER_OUTPUTS];
1296 LLVMBuilderRef builder = ctx->ac.builder;
1297 LLVMValueRef *addrs = abi->outputs;
1298 LLVMValueRef tmp, tmp2;
1299
1300 assert(!ctx->shader->is_gs_copy_shader);
1301 assert(info->num_outputs <= AC_LLVM_MAX_OUTPUTS);
1302
1303 LLVMValueRef vertex_ptr = NULL;
1304
1305 if (sel->so.num_outputs || gfx10_ngg_writes_user_edgeflags(ctx->shader))
1306 vertex_ptr = ngg_nogs_vertex_ptr(ctx, get_thread_id_in_tg(ctx));
1307
1308 for (unsigned i = 0; i < info->num_outputs; i++) {
1309 outputs[i].semantic = info->output_semantic[i];
1310
1311 for (unsigned j = 0; j < 4; j++) {
1312 outputs[i].vertex_stream[j] = (info->output_streams[i] >> (2 * j)) & 3;
1313
1314 /* TODO: we may store more outputs than streamout needs,
1315 * but streamout performance isn't that important.
1316 */
1317 if (sel->so.num_outputs) {
1318 tmp = ac_build_gep0(&ctx->ac, vertex_ptr, LLVMConstInt(ctx->ac.i32, 4 * i + j, false));
1319 tmp2 = LLVMBuildLoad(builder, addrs[4 * i + j], "");
1320 tmp2 = ac_to_integer(&ctx->ac, tmp2);
1321 LLVMBuildStore(builder, tmp2, tmp);
1322 }
1323 }
1324
1325 /* Store the edgeflag at the end (if streamout is enabled) */
1326 if (info->output_semantic[i] == VARYING_SLOT_EDGE && gfx10_ngg_writes_user_edgeflags(ctx->shader)) {
1327 LLVMValueRef edgeflag = LLVMBuildLoad(builder, addrs[4 * i], "");
1328 /* The output is a float, but the hw expects a 1-bit integer. */
1329 edgeflag = LLVMBuildFPToUI(ctx->ac.builder, edgeflag, ctx->ac.i32, "");
1330 edgeflag = ac_build_umin(&ctx->ac, edgeflag, ctx->ac.i32_1);
1331
1332 tmp = LLVMConstInt(ctx->ac.i32, ngg_nogs_vertex_size(ctx->shader) - 1, 0);
1333 tmp = ac_build_gep0(&ctx->ac, vertex_ptr, tmp);
1334 LLVMBuildStore(builder, edgeflag, tmp);
1335 }
1336 }
1337
1338 bool unterminated_es_if_block =
1339 !sel->so.num_outputs && !gfx10_ngg_writes_user_edgeflags(ctx->shader) &&
1340 !ctx->screen->use_ngg_streamout && /* no query buffer */
1341 (ctx->stage != MESA_SHADER_VERTEX || !ctx->shader->key.mono.u.vs_export_prim_id);
1342
1343 if (!unterminated_es_if_block)
1344 ac_build_endif(&ctx->ac, ctx->merged_wrap_if_label);
1345
1346 LLVMValueRef is_gs_thread = si_is_gs_thread(ctx);
1347 LLVMValueRef is_es_thread = si_is_es_thread(ctx);
1348 LLVMValueRef vtxindex[3];
1349
1350 if (ctx->shader->key.opt.ngg_culling || gfx10_is_ngg_passthrough(ctx->shader)) {
1351 for (unsigned i = 0; i < 3; ++i)
1352 vtxindex[i] = si_unpack_param(ctx, ctx->args.gs_vtx_offset[0], 10 * i, 9);
1353 } else {
1354 for (unsigned i = 0; i < 3; ++i)
1355 vtxindex[i] = si_unpack_param(ctx, ctx->args.gs_vtx_offset[i / 2], (i & 1) * 16, 16);
1356 }
1357
1358 /* Determine the number of vertices per primitive. */
1359 unsigned num_vertices;
1360 LLVMValueRef num_vertices_val = ngg_get_vertices_per_prim(ctx, &num_vertices);
1361
1362 /* Streamout */
1363 LLVMValueRef emitted_prims = NULL;
1364
1365 if (sel->so.num_outputs) {
1366 assert(!unterminated_es_if_block);
1367
1368 struct ngg_streamout nggso = {};
1369 nggso.num_vertices = num_vertices_val;
1370 nggso.prim_enable[0] = is_gs_thread;
1371
1372 for (unsigned i = 0; i < num_vertices; ++i)
1373 nggso.vertices[i] = ngg_nogs_vertex_ptr(ctx, vtxindex[i]);
1374
1375 build_streamout(ctx, &nggso);
1376 emitted_prims = nggso.emit[0];
1377 }
1378
1379 LLVMValueRef user_edgeflags[3] = {};
1380
1381 if (gfx10_ngg_writes_user_edgeflags(ctx->shader)) {
1382 assert(!unterminated_es_if_block);
1383
1384 /* Streamout already inserted the barrier, so don't insert it again. */
1385 if (!sel->so.num_outputs)
1386 ac_build_s_barrier(&ctx->ac);
1387
1388 ac_build_ifcc(&ctx->ac, is_gs_thread, 5400);
1389 /* Load edge flags from ES threads and store them into VGPRs in GS threads. */
1390 for (unsigned i = 0; i < num_vertices; i++) {
1391 tmp = ngg_nogs_vertex_ptr(ctx, vtxindex[i]);
1392 tmp2 = LLVMConstInt(ctx->ac.i32, ngg_nogs_vertex_size(ctx->shader) - 1, 0);
1393 tmp = ac_build_gep0(&ctx->ac, tmp, tmp2);
1394 tmp = LLVMBuildLoad(builder, tmp, "");
1395 tmp = LLVMBuildTrunc(builder, tmp, ctx->ac.i1, "");
1396
1397 user_edgeflags[i] = ac_build_alloca_init(&ctx->ac, tmp, "");
1398 }
1399 ac_build_endif(&ctx->ac, 5400);
1400 }
1401
1402 /* Copy Primitive IDs from GS threads to the LDS address corresponding
1403 * to the ES thread of the provoking vertex.
1404 */
1405 if (ctx->stage == MESA_SHADER_VERTEX && ctx->shader->key.mono.u.vs_export_prim_id) {
1406 assert(!unterminated_es_if_block);
1407
1408 /* Streamout and edge flags use LDS. Make it idle, so that we can reuse it. */
1409 if (sel->so.num_outputs || gfx10_ngg_writes_user_edgeflags(ctx->shader))
1410 ac_build_s_barrier(&ctx->ac);
1411
1412 ac_build_ifcc(&ctx->ac, is_gs_thread, 5400);
1413 /* Extract the PROVOKING_VTX_INDEX field. */
1414 LLVMValueRef provoking_vtx_in_prim = si_unpack_param(ctx, ctx->vs_state_bits, 4, 2);
1415
1416 /* provoking_vtx_index = vtxindex[provoking_vtx_in_prim]; */
1417 LLVMValueRef indices = ac_build_gather_values(&ctx->ac, vtxindex, 3);
1418 LLVMValueRef provoking_vtx_index =
1419 LLVMBuildExtractElement(builder, indices, provoking_vtx_in_prim, "");
1420 LLVMValueRef vertex_ptr = ngg_nogs_vertex_ptr(ctx, provoking_vtx_index);
1421
1422 LLVMBuildStore(builder, ac_get_arg(&ctx->ac, ctx->args.gs_prim_id),
1423 ac_build_gep0(&ctx->ac, vertex_ptr, ctx->ac.i32_0));
1424 ac_build_endif(&ctx->ac, 5400);
1425 }
1426
1427 /* Update query buffer */
1428 if (ctx->screen->use_ngg_streamout && !info->base.vs.blit_sgprs_amd) {
1429 assert(!unterminated_es_if_block);
1430
1431 tmp = si_unpack_param(ctx, ctx->vs_state_bits, 6, 1);
1432 tmp = LLVMBuildTrunc(builder, tmp, ctx->ac.i1, "");
1433 ac_build_ifcc(&ctx->ac, tmp, 5029); /* if (STREAMOUT_QUERY_ENABLED) */
1434 tmp = LLVMBuildICmp(builder, LLVMIntEQ, get_wave_id_in_tg(ctx), ctx->ac.i32_0, "");
1435 ac_build_ifcc(&ctx->ac, tmp, 5030);
1436 tmp = LLVMBuildICmp(builder, LLVMIntULE, ac_get_thread_id(&ctx->ac),
1437 sel->so.num_outputs ? ctx->ac.i32_1 : ctx->ac.i32_0, "");
1438 ac_build_ifcc(&ctx->ac, tmp, 5031);
1439 {
1440 LLVMValueRef args[] = {
1441 ngg_get_prim_cnt(ctx),
1442 ngg_get_query_buf(ctx),
1443 LLVMConstInt(ctx->ac.i32, 16, false), /* offset of stream[0].generated_primitives */
1444 ctx->ac.i32_0, /* soffset */
1445 ctx->ac.i32_0, /* cachepolicy */
1446 };
1447
1448 if (sel->so.num_outputs) {
1449 args[0] = ac_build_writelane(&ctx->ac, args[0], emitted_prims, ctx->ac.i32_1);
1450 args[2] = ac_build_writelane(&ctx->ac, args[2], LLVMConstInt(ctx->ac.i32, 24, false),
1451 ctx->ac.i32_1);
1452 }
1453
1454 /* TODO: should this be 64-bit atomics? */
1455 ac_build_intrinsic(&ctx->ac, "llvm.amdgcn.raw.buffer.atomic.add.i32", ctx->ac.i32, args, 5,
1456 0);
1457 }
1458 ac_build_endif(&ctx->ac, 5031);
1459 ac_build_endif(&ctx->ac, 5030);
1460 ac_build_endif(&ctx->ac, 5029);
1461 }
1462
1463 /* Build the primitive export. */
1464 if (!gfx10_ngg_export_prim_early(ctx->shader)) {
1465 assert(!unterminated_es_if_block);
1466 gfx10_ngg_build_export_prim(ctx, user_edgeflags, NULL);
1467 }
1468
1469 /* Export per-vertex data (positions and parameters). */
1470 if (!unterminated_es_if_block)
1471 ac_build_ifcc(&ctx->ac, is_es_thread, 6002);
1472 {
1473 unsigned i;
1474
1475 /* Unconditionally (re-)load the values for proper SSA form. */
1476 for (i = 0; i < info->num_outputs; i++) {
1477 /* If the NGG cull shader part computed the position, don't
1478 * use the position from the current shader part. Instead,
1479 * load it from LDS.
1480 */
1481 if (info->output_semantic[i] == VARYING_SLOT_POS &&
1482 ctx->shader->key.opt.ngg_culling) {
1483 vertex_ptr = ngg_nogs_vertex_ptr(ctx, get_thread_id_in_tg(ctx));
1484
1485 for (unsigned j = 0; j < 4; j++) {
1486 tmp = LLVMConstInt(ctx->ac.i32, lds_pos_x + j, 0);
1487 tmp = ac_build_gep0(&ctx->ac, vertex_ptr, tmp);
1488 tmp = LLVMBuildLoad(builder, tmp, "");
1489 outputs[i].values[j] = ac_to_float(&ctx->ac, tmp);
1490 }
1491 } else {
1492 for (unsigned j = 0; j < 4; j++) {
1493 outputs[i].values[j] = LLVMBuildLoad(builder, addrs[4 * i + j], "");
1494 }
1495 }
1496 }
1497
1498 if (ctx->shader->key.mono.u.vs_export_prim_id) {
1499 outputs[i].semantic = VARYING_SLOT_PRIMITIVE_ID;
1500
1501 if (ctx->stage == MESA_SHADER_VERTEX) {
1502 /* Wait for GS stores to finish. */
1503 ac_build_s_barrier(&ctx->ac);
1504
1505 tmp = ngg_nogs_vertex_ptr(ctx, get_thread_id_in_tg(ctx));
1506 tmp = ac_build_gep0(&ctx->ac, tmp, ctx->ac.i32_0);
1507 outputs[i].values[0] = LLVMBuildLoad(builder, tmp, "");
1508 } else {
1509 assert(ctx->stage == MESA_SHADER_TESS_EVAL);
1510 outputs[i].values[0] = si_get_primitive_id(ctx, 0);
1511 }
1512
1513 outputs[i].values[0] = ac_to_float(&ctx->ac, outputs[i].values[0]);
1514 for (unsigned j = 1; j < 4; j++)
1515 outputs[i].values[j] = LLVMGetUndef(ctx->ac.f32);
1516
1517 memset(outputs[i].vertex_stream, 0, sizeof(outputs[i].vertex_stream));
1518 i++;
1519 }
1520
1521 si_llvm_build_vs_exports(ctx, outputs, i);
1522 }
1523 ac_build_endif(&ctx->ac, 6002);
1524 }
1525
ngg_gs_get_vertex_storage(struct si_shader_context * ctx)1526 static LLVMValueRef ngg_gs_get_vertex_storage(struct si_shader_context *ctx)
1527 {
1528 const struct si_shader_selector *sel = ctx->shader->selector;
1529 const struct si_shader_info *info = &sel->info;
1530
1531 LLVMTypeRef elements[2] = {
1532 LLVMArrayType(ctx->ac.i32, 4 * info->num_outputs),
1533 LLVMArrayType(ctx->ac.i8, 4),
1534 };
1535 LLVMTypeRef type = LLVMStructTypeInContext(ctx->ac.context, elements, 2, false);
1536 type = LLVMPointerType(LLVMArrayType(type, 0), AC_ADDR_SPACE_LDS);
1537 return LLVMBuildBitCast(ctx->ac.builder, ctx->gs_ngg_emit, type, "");
1538 }
1539
1540 /**
1541 * Return a pointer to the LDS storage reserved for the N'th vertex, where N
1542 * is in emit order; that is:
1543 * - during the epilogue, N is the threadidx (relative to the entire threadgroup)
1544 * - during vertex emit, i.e. while the API GS shader invocation is running,
1545 * N = threadidx * gs.vertices_out + emitidx
1546 *
1547 * Goals of the LDS memory layout:
1548 * 1. Eliminate bank conflicts on write for geometry shaders that have all emits
1549 * in uniform control flow
1550 * 2. Eliminate bank conflicts on read for export if, additionally, there is no
1551 * culling
1552 * 3. Agnostic to the number of waves (since we don't know it before compiling)
1553 * 4. Allow coalescing of LDS instructions (ds_write_b128 etc.)
1554 * 5. Avoid wasting memory.
1555 *
1556 * We use an AoS layout due to point 4 (this also helps point 3). In an AoS
1557 * layout, elimination of bank conflicts requires that each vertex occupy an
1558 * odd number of dwords. We use the additional dword to store the output stream
1559 * index as well as a flag to indicate whether this vertex ends a primitive
1560 * for rasterization.
1561 *
1562 * Swizzling is required to satisfy points 1 and 2 simultaneously.
1563 *
1564 * Vertices are stored in export order (gsthread * gs.vertices_out + emitidx).
1565 * Indices are swizzled in groups of 32, which ensures point 1 without
1566 * disturbing point 2.
1567 *
1568 * \return an LDS pointer to type {[N x i32], [4 x i8]}
1569 */
ngg_gs_vertex_ptr(struct si_shader_context * ctx,LLVMValueRef vertexidx)1570 static LLVMValueRef ngg_gs_vertex_ptr(struct si_shader_context *ctx, LLVMValueRef vertexidx)
1571 {
1572 struct si_shader_selector *sel = ctx->shader->selector;
1573 LLVMBuilderRef builder = ctx->ac.builder;
1574 LLVMValueRef storage = ngg_gs_get_vertex_storage(ctx);
1575
1576 /* gs.vertices_out = 2^(write_stride_2exp) * some odd number */
1577 unsigned write_stride_2exp = ffs(sel->info.base.gs.vertices_out) - 1;
1578 if (write_stride_2exp) {
1579 LLVMValueRef row = LLVMBuildLShr(builder, vertexidx, LLVMConstInt(ctx->ac.i32, 5, false), "");
1580 LLVMValueRef swizzle = LLVMBuildAnd(
1581 builder, row, LLVMConstInt(ctx->ac.i32, (1u << write_stride_2exp) - 1, false), "");
1582 vertexidx = LLVMBuildXor(builder, vertexidx, swizzle, "");
1583 }
1584
1585 return ac_build_gep0(&ctx->ac, storage, vertexidx);
1586 }
1587
ngg_gs_emit_vertex_ptr(struct si_shader_context * ctx,LLVMValueRef gsthread,LLVMValueRef emitidx)1588 static LLVMValueRef ngg_gs_emit_vertex_ptr(struct si_shader_context *ctx, LLVMValueRef gsthread,
1589 LLVMValueRef emitidx)
1590 {
1591 struct si_shader_selector *sel = ctx->shader->selector;
1592 LLVMBuilderRef builder = ctx->ac.builder;
1593 LLVMValueRef tmp;
1594
1595 tmp = LLVMConstInt(ctx->ac.i32, sel->info.base.gs.vertices_out, false);
1596 tmp = LLVMBuildMul(builder, tmp, gsthread, "");
1597 const LLVMValueRef vertexidx = LLVMBuildAdd(builder, tmp, emitidx, "");
1598 return ngg_gs_vertex_ptr(ctx, vertexidx);
1599 }
1600
ngg_gs_get_emit_output_ptr(struct si_shader_context * ctx,LLVMValueRef vertexptr,unsigned out_idx)1601 static LLVMValueRef ngg_gs_get_emit_output_ptr(struct si_shader_context *ctx,
1602 LLVMValueRef vertexptr, unsigned out_idx)
1603 {
1604 LLVMValueRef gep_idx[3] = {
1605 ctx->ac.i32_0, /* implied C-style array */
1606 ctx->ac.i32_0, /* first struct entry */
1607 LLVMConstInt(ctx->ac.i32, out_idx, false),
1608 };
1609 return LLVMBuildGEP(ctx->ac.builder, vertexptr, gep_idx, 3, "");
1610 }
1611
ngg_gs_get_emit_primflag_ptr(struct si_shader_context * ctx,LLVMValueRef vertexptr,unsigned stream)1612 static LLVMValueRef ngg_gs_get_emit_primflag_ptr(struct si_shader_context *ctx,
1613 LLVMValueRef vertexptr, unsigned stream)
1614 {
1615 LLVMValueRef gep_idx[3] = {
1616 ctx->ac.i32_0, /* implied C-style array */
1617 ctx->ac.i32_1, /* second struct entry */
1618 LLVMConstInt(ctx->ac.i32, stream, false),
1619 };
1620 return LLVMBuildGEP(ctx->ac.builder, vertexptr, gep_idx, 3, "");
1621 }
1622
gfx10_ngg_gs_emit_vertex(struct si_shader_context * ctx,unsigned stream,LLVMValueRef * addrs)1623 void gfx10_ngg_gs_emit_vertex(struct si_shader_context *ctx, unsigned stream, LLVMValueRef *addrs)
1624 {
1625 const struct si_shader_selector *sel = ctx->shader->selector;
1626 const struct si_shader_info *info = &sel->info;
1627 LLVMBuilderRef builder = ctx->ac.builder;
1628 LLVMValueRef tmp;
1629 const LLVMValueRef vertexidx = LLVMBuildLoad(builder, ctx->gs_next_vertex[stream], "");
1630
1631 /* If this thread has already emitted the declared maximum number of
1632 * vertices, skip the write: excessive vertex emissions are not
1633 * supposed to have any effect.
1634 */
1635 const LLVMValueRef can_emit =
1636 LLVMBuildICmp(builder, LLVMIntULT, vertexidx,
1637 LLVMConstInt(ctx->ac.i32, sel->info.base.gs.vertices_out, false), "");
1638
1639 tmp = LLVMBuildAdd(builder, vertexidx, ctx->ac.i32_1, "");
1640 tmp = LLVMBuildSelect(builder, can_emit, tmp, vertexidx, "");
1641 LLVMBuildStore(builder, tmp, ctx->gs_next_vertex[stream]);
1642
1643 ac_build_ifcc(&ctx->ac, can_emit, 9001);
1644
1645 const LLVMValueRef vertexptr = ngg_gs_emit_vertex_ptr(ctx, get_thread_id_in_tg(ctx), vertexidx);
1646 unsigned out_idx = 0;
1647 for (unsigned i = 0; i < info->num_outputs; i++) {
1648 for (unsigned chan = 0; chan < 4; chan++, out_idx++) {
1649 if (!(info->output_usagemask[i] & (1 << chan)) ||
1650 ((info->output_streams[i] >> (2 * chan)) & 3) != stream)
1651 continue;
1652
1653 LLVMValueRef out_val = LLVMBuildLoad(builder, addrs[4 * i + chan], "");
1654 out_val = ac_to_integer(&ctx->ac, out_val);
1655 LLVMBuildStore(builder, out_val, ngg_gs_get_emit_output_ptr(ctx, vertexptr, out_idx));
1656 }
1657 }
1658 assert(out_idx * 4 == sel->gsvs_vertex_size);
1659
1660 /* Determine and store whether this vertex completed a primitive. */
1661 const LLVMValueRef curverts = LLVMBuildLoad(builder, ctx->gs_curprim_verts[stream], "");
1662
1663 tmp = LLVMConstInt(ctx->ac.i32, u_vertices_per_prim(sel->info.base.gs.output_primitive) - 1, false);
1664 const LLVMValueRef iscompleteprim = LLVMBuildICmp(builder, LLVMIntUGE, curverts, tmp, "");
1665
1666 /* Since the geometry shader emits triangle strips, we need to
1667 * track which primitive is odd and swap vertex indices to get
1668 * the correct vertex order.
1669 */
1670 LLVMValueRef is_odd = ctx->ac.i1false;
1671 if (stream == 0 && u_vertices_per_prim(sel->info.base.gs.output_primitive) == 3) {
1672 tmp = LLVMBuildAnd(builder, curverts, ctx->ac.i32_1, "");
1673 is_odd = LLVMBuildICmp(builder, LLVMIntEQ, tmp, ctx->ac.i32_1, "");
1674 }
1675
1676 tmp = LLVMBuildAdd(builder, curverts, ctx->ac.i32_1, "");
1677 LLVMBuildStore(builder, tmp, ctx->gs_curprim_verts[stream]);
1678
1679 /* The per-vertex primitive flag encoding:
1680 * bit 0: whether this vertex finishes a primitive
1681 * bit 1: whether the primitive is odd (if we are emitting triangle strips)
1682 */
1683 tmp = LLVMBuildZExt(builder, iscompleteprim, ctx->ac.i8, "");
1684 tmp = LLVMBuildOr(
1685 builder, tmp,
1686 LLVMBuildShl(builder, LLVMBuildZExt(builder, is_odd, ctx->ac.i8, ""), ctx->ac.i8_1, ""), "");
1687 LLVMBuildStore(builder, tmp, ngg_gs_get_emit_primflag_ptr(ctx, vertexptr, stream));
1688
1689 tmp = LLVMBuildLoad(builder, ctx->gs_generated_prims[stream], "");
1690 tmp = LLVMBuildAdd(builder, tmp, LLVMBuildZExt(builder, iscompleteprim, ctx->ac.i32, ""), "");
1691 LLVMBuildStore(builder, tmp, ctx->gs_generated_prims[stream]);
1692
1693 ac_build_endif(&ctx->ac, 9001);
1694 }
1695
gfx10_ngg_gs_emit_prologue(struct si_shader_context * ctx)1696 void gfx10_ngg_gs_emit_prologue(struct si_shader_context *ctx)
1697 {
1698 /* Zero out the part of LDS scratch that is used to accumulate the
1699 * per-stream generated primitive count.
1700 */
1701 LLVMBuilderRef builder = ctx->ac.builder;
1702 LLVMValueRef scratchptr = ctx->gs_ngg_scratch;
1703 LLVMValueRef tid = get_thread_id_in_tg(ctx);
1704 LLVMValueRef tmp;
1705
1706 tmp = LLVMBuildICmp(builder, LLVMIntULT, tid, LLVMConstInt(ctx->ac.i32, 4, false), "");
1707 ac_build_ifcc(&ctx->ac, tmp, 5090);
1708 {
1709 LLVMValueRef ptr = ac_build_gep0(&ctx->ac, scratchptr, tid);
1710 LLVMBuildStore(builder, ctx->ac.i32_0, ptr);
1711 }
1712 ac_build_endif(&ctx->ac, 5090);
1713
1714 ac_build_s_barrier(&ctx->ac);
1715 }
1716
gfx10_ngg_gs_emit_epilogue(struct si_shader_context * ctx)1717 void gfx10_ngg_gs_emit_epilogue(struct si_shader_context *ctx)
1718 {
1719 const struct si_shader_selector *sel = ctx->shader->selector;
1720 const struct si_shader_info *info = &sel->info;
1721 const unsigned verts_per_prim = u_vertices_per_prim(sel->info.base.gs.output_primitive);
1722 LLVMBuilderRef builder = ctx->ac.builder;
1723 LLVMValueRef i8_0 = LLVMConstInt(ctx->ac.i8, 0, false);
1724 LLVMValueRef tmp, tmp2;
1725
1726 /* Zero out remaining (non-emitted) primitive flags.
1727 *
1728 * Note: Alternatively, we could pass the relevant gs_next_vertex to
1729 * the emit threads via LDS. This is likely worse in the expected
1730 * typical case where each GS thread emits the full set of
1731 * vertices.
1732 */
1733 for (unsigned stream = 0; stream < 4; ++stream) {
1734 if (!info->num_stream_output_components[stream])
1735 continue;
1736
1737 const LLVMValueRef gsthread = get_thread_id_in_tg(ctx);
1738
1739 ac_build_bgnloop(&ctx->ac, 5100);
1740
1741 const LLVMValueRef vertexidx = LLVMBuildLoad(builder, ctx->gs_next_vertex[stream], "");
1742 tmp = LLVMBuildICmp(builder, LLVMIntUGE, vertexidx,
1743 LLVMConstInt(ctx->ac.i32, sel->info.base.gs.vertices_out, false), "");
1744 ac_build_ifcc(&ctx->ac, tmp, 5101);
1745 ac_build_break(&ctx->ac);
1746 ac_build_endif(&ctx->ac, 5101);
1747
1748 tmp = LLVMBuildAdd(builder, vertexidx, ctx->ac.i32_1, "");
1749 LLVMBuildStore(builder, tmp, ctx->gs_next_vertex[stream]);
1750
1751 tmp = ngg_gs_emit_vertex_ptr(ctx, gsthread, vertexidx);
1752 LLVMBuildStore(builder, i8_0, ngg_gs_get_emit_primflag_ptr(ctx, tmp, stream));
1753
1754 ac_build_endloop(&ctx->ac, 5100);
1755 }
1756
1757 /* Accumulate generated primitives counts across the entire threadgroup. */
1758 for (unsigned stream = 0; stream < 4; ++stream) {
1759 if (!info->num_stream_output_components[stream])
1760 continue;
1761
1762 LLVMValueRef numprims = LLVMBuildLoad(builder, ctx->gs_generated_prims[stream], "");
1763 numprims = ac_build_reduce(&ctx->ac, numprims, nir_op_iadd, ctx->ac.wave_size);
1764
1765 tmp = LLVMBuildICmp(builder, LLVMIntEQ, ac_get_thread_id(&ctx->ac), ctx->ac.i32_0, "");
1766 ac_build_ifcc(&ctx->ac, tmp, 5105);
1767 {
1768 LLVMBuildAtomicRMW(
1769 builder, LLVMAtomicRMWBinOpAdd,
1770 ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch, LLVMConstInt(ctx->ac.i32, stream, false)),
1771 numprims, LLVMAtomicOrderingMonotonic, false);
1772 }
1773 ac_build_endif(&ctx->ac, 5105);
1774 }
1775
1776 ac_build_endif(&ctx->ac, ctx->merged_wrap_if_label);
1777
1778 ac_build_s_barrier(&ctx->ac);
1779
1780 const LLVMValueRef tid = get_thread_id_in_tg(ctx);
1781 LLVMValueRef num_emit_threads = ngg_get_prim_cnt(ctx);
1782
1783 /* Streamout */
1784 if (sel->so.num_outputs) {
1785 struct ngg_streamout nggso = {};
1786
1787 nggso.num_vertices = LLVMConstInt(ctx->ac.i32, verts_per_prim, false);
1788
1789 LLVMValueRef vertexptr = ngg_gs_vertex_ptr(ctx, tid);
1790 for (unsigned stream = 0; stream < 4; ++stream) {
1791 if (!info->num_stream_output_components[stream])
1792 continue;
1793
1794 tmp = LLVMBuildLoad(builder, ngg_gs_get_emit_primflag_ptr(ctx, vertexptr, stream), "");
1795 tmp = LLVMBuildTrunc(builder, tmp, ctx->ac.i1, "");
1796 tmp2 = LLVMBuildICmp(builder, LLVMIntULT, tid, num_emit_threads, "");
1797 nggso.prim_enable[stream] = LLVMBuildAnd(builder, tmp, tmp2, "");
1798 }
1799
1800 for (unsigned i = 0; i < verts_per_prim; ++i) {
1801 tmp = LLVMBuildSub(builder, tid, LLVMConstInt(ctx->ac.i32, verts_per_prim - i - 1, false),
1802 "");
1803 tmp = ngg_gs_vertex_ptr(ctx, tmp);
1804 nggso.vertices[i] = ac_build_gep0(&ctx->ac, tmp, ctx->ac.i32_0);
1805 }
1806
1807 build_streamout(ctx, &nggso);
1808 }
1809
1810 /* Write shader query data. */
1811 if (ctx->screen->use_ngg_streamout) {
1812 tmp = si_unpack_param(ctx, ctx->vs_state_bits, 6, 1);
1813 tmp = LLVMBuildTrunc(builder, tmp, ctx->ac.i1, "");
1814 ac_build_ifcc(&ctx->ac, tmp, 5109); /* if (STREAMOUT_QUERY_ENABLED) */
1815 unsigned num_query_comps = sel->so.num_outputs ? 8 : 4;
1816 tmp = LLVMBuildICmp(builder, LLVMIntULT, tid,
1817 LLVMConstInt(ctx->ac.i32, num_query_comps, false), "");
1818 ac_build_ifcc(&ctx->ac, tmp, 5110);
1819 {
1820 LLVMValueRef offset;
1821 tmp = tid;
1822 if (sel->so.num_outputs)
1823 tmp = LLVMBuildAnd(builder, tmp, LLVMConstInt(ctx->ac.i32, 3, false), "");
1824 offset = LLVMBuildNUWMul(builder, tmp, LLVMConstInt(ctx->ac.i32, 32, false), "");
1825 if (sel->so.num_outputs) {
1826 tmp = LLVMBuildLShr(builder, tid, LLVMConstInt(ctx->ac.i32, 2, false), "");
1827 tmp = LLVMBuildNUWMul(builder, tmp, LLVMConstInt(ctx->ac.i32, 8, false), "");
1828 offset = LLVMBuildAdd(builder, offset, tmp, "");
1829 }
1830
1831 tmp = LLVMBuildLoad(builder, ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch, tid), "");
1832 LLVMValueRef args[] = {
1833 tmp, ngg_get_query_buf(ctx),
1834 offset, LLVMConstInt(ctx->ac.i32, 16, false), /* soffset */
1835 ctx->ac.i32_0, /* cachepolicy */
1836 };
1837 ac_build_intrinsic(&ctx->ac, "llvm.amdgcn.raw.buffer.atomic.add.i32", ctx->ac.i32, args, 5,
1838 0);
1839 }
1840 ac_build_endif(&ctx->ac, 5110);
1841 ac_build_endif(&ctx->ac, 5109);
1842 }
1843
1844 /* Determine vertex liveness. */
1845 LLVMValueRef vertliveptr = ac_build_alloca(&ctx->ac, ctx->ac.i1, "vertexlive");
1846
1847 tmp = LLVMBuildICmp(builder, LLVMIntULT, tid, num_emit_threads, "");
1848 ac_build_ifcc(&ctx->ac, tmp, 5120);
1849 {
1850 for (unsigned i = 0; i < verts_per_prim; ++i) {
1851 const LLVMValueRef primidx =
1852 LLVMBuildAdd(builder, tid, LLVMConstInt(ctx->ac.i32, i, false), "");
1853
1854 if (i > 0) {
1855 tmp = LLVMBuildICmp(builder, LLVMIntULT, primidx, num_emit_threads, "");
1856 ac_build_ifcc(&ctx->ac, tmp, 5121 + i);
1857 }
1858
1859 /* Load primitive liveness */
1860 tmp = ngg_gs_vertex_ptr(ctx, primidx);
1861 tmp = LLVMBuildLoad(builder, ngg_gs_get_emit_primflag_ptr(ctx, tmp, 0), "");
1862 const LLVMValueRef primlive = LLVMBuildTrunc(builder, tmp, ctx->ac.i1, "");
1863
1864 tmp = LLVMBuildLoad(builder, vertliveptr, "");
1865 tmp = LLVMBuildOr(builder, tmp, primlive, ""), LLVMBuildStore(builder, tmp, vertliveptr);
1866
1867 if (i > 0)
1868 ac_build_endif(&ctx->ac, 5121 + i);
1869 }
1870 }
1871 ac_build_endif(&ctx->ac, 5120);
1872
1873 /* Inclusive scan addition across the current wave. */
1874 LLVMValueRef vertlive = LLVMBuildLoad(builder, vertliveptr, "");
1875 struct ac_wg_scan vertlive_scan = {};
1876 vertlive_scan.op = nir_op_iadd;
1877 vertlive_scan.enable_reduce = true;
1878 vertlive_scan.enable_exclusive = true;
1879 vertlive_scan.src = vertlive;
1880 vertlive_scan.scratch = ac_build_gep0(&ctx->ac, ctx->gs_ngg_scratch, ctx->ac.i32_0);
1881 vertlive_scan.waveidx = get_wave_id_in_tg(ctx);
1882 vertlive_scan.numwaves = get_tgsize(ctx);
1883 vertlive_scan.maxwaves = DIV_ROUND_UP(256, ctx->ac.wave_size);
1884
1885 ac_build_wg_scan(&ctx->ac, &vertlive_scan);
1886
1887 /* Skip all exports (including index exports) when possible. */
1888 LLVMValueRef have_exports =
1889 LLVMBuildICmp(builder, LLVMIntNE, vertlive_scan.result_reduce, ctx->ac.i32_0, "");
1890 num_emit_threads = LLVMBuildSelect(builder, have_exports, num_emit_threads, ctx->ac.i32_0, "");
1891
1892 /* Allocate export space. Send this message as early as possible, to
1893 * hide the latency of the SQ <-> SPI roundtrip.
1894 */
1895 ac_build_sendmsg_gs_alloc_req(&ctx->ac, get_wave_id_in_tg(ctx), vertlive_scan.result_reduce,
1896 num_emit_threads);
1897
1898 /* Setup the reverse vertex compaction permutation. We re-use stream 1
1899 * of the primitive liveness flags, relying on the fact that each
1900 * threadgroup can have at most 256 threads. */
1901 ac_build_ifcc(&ctx->ac, vertlive, 5130);
1902 {
1903 tmp = ngg_gs_vertex_ptr(ctx, vertlive_scan.result_exclusive);
1904 tmp2 = LLVMBuildTrunc(builder, tid, ctx->ac.i8, "");
1905 LLVMBuildStore(builder, tmp2, ngg_gs_get_emit_primflag_ptr(ctx, tmp, 1));
1906 }
1907 ac_build_endif(&ctx->ac, 5130);
1908
1909 ac_build_s_barrier(&ctx->ac);
1910
1911 /* Export primitive data */
1912 tmp = LLVMBuildICmp(builder, LLVMIntULT, tid, num_emit_threads, "");
1913 ac_build_ifcc(&ctx->ac, tmp, 5140);
1914 {
1915 LLVMValueRef flags;
1916 struct ac_ngg_prim prim = {};
1917 prim.num_vertices = verts_per_prim;
1918
1919 tmp = ngg_gs_vertex_ptr(ctx, tid);
1920 flags = LLVMBuildLoad(builder, ngg_gs_get_emit_primflag_ptr(ctx, tmp, 0), "");
1921 prim.isnull = LLVMBuildNot(builder, LLVMBuildTrunc(builder, flags, ctx->ac.i1, ""), "");
1922 prim.edgeflags = ctx->ac.i32_0;
1923
1924 for (unsigned i = 0; i < verts_per_prim; ++i) {
1925 prim.index[i] = LLVMBuildSub(builder, vertlive_scan.result_exclusive,
1926 LLVMConstInt(ctx->ac.i32, verts_per_prim - i - 1, false), "");
1927 }
1928
1929 /* Geometry shaders output triangle strips, but NGG expects triangles. */
1930 if (verts_per_prim == 3) {
1931 LLVMValueRef is_odd = LLVMBuildLShr(builder, flags, ctx->ac.i8_1, "");
1932 is_odd = LLVMBuildTrunc(builder, is_odd, ctx->ac.i1, "");
1933 LLVMValueRef flatshade_first = LLVMBuildICmp(
1934 builder, LLVMIntEQ, si_unpack_param(ctx, ctx->vs_state_bits, 4, 2), ctx->ac.i32_0, "");
1935
1936 ac_build_triangle_strip_indices_to_triangle(&ctx->ac, is_odd, flatshade_first, prim.index);
1937 }
1938
1939 ac_build_export_prim(&ctx->ac, &prim);
1940 }
1941 ac_build_endif(&ctx->ac, 5140);
1942
1943 /* Export position and parameter data */
1944 tmp = LLVMBuildICmp(builder, LLVMIntULT, tid, vertlive_scan.result_reduce, "");
1945 ac_build_ifcc(&ctx->ac, tmp, 5145);
1946 {
1947 struct si_shader_output_values outputs[PIPE_MAX_SHADER_OUTPUTS];
1948
1949 tmp = ngg_gs_vertex_ptr(ctx, tid);
1950 tmp = LLVMBuildLoad(builder, ngg_gs_get_emit_primflag_ptr(ctx, tmp, 1), "");
1951 tmp = LLVMBuildZExt(builder, tmp, ctx->ac.i32, "");
1952 const LLVMValueRef vertexptr = ngg_gs_vertex_ptr(ctx, tmp);
1953
1954 unsigned out_idx = 0;
1955 for (unsigned i = 0; i < info->num_outputs; i++) {
1956 outputs[i].semantic = info->output_semantic[i];
1957
1958 for (unsigned j = 0; j < 4; j++, out_idx++) {
1959 tmp = ngg_gs_get_emit_output_ptr(ctx, vertexptr, out_idx);
1960 tmp = LLVMBuildLoad(builder, tmp, "");
1961 outputs[i].values[j] = ac_to_float(&ctx->ac, tmp);
1962 outputs[i].vertex_stream[j] = (info->output_streams[i] >> (2 * j)) & 3;
1963 }
1964 }
1965
1966 si_llvm_build_vs_exports(ctx, outputs, info->num_outputs);
1967 }
1968 ac_build_endif(&ctx->ac, 5145);
1969 }
1970
clamp_gsprims_to_esverts(unsigned * max_gsprims,unsigned max_esverts,unsigned min_verts_per_prim,bool use_adjacency)1971 static void clamp_gsprims_to_esverts(unsigned *max_gsprims, unsigned max_esverts,
1972 unsigned min_verts_per_prim, bool use_adjacency)
1973 {
1974 unsigned max_reuse = max_esverts - min_verts_per_prim;
1975 if (use_adjacency)
1976 max_reuse /= 2;
1977 *max_gsprims = MIN2(*max_gsprims, 1 + max_reuse);
1978 }
1979
gfx10_ngg_get_scratch_dw_size(struct si_shader * shader)1980 unsigned gfx10_ngg_get_scratch_dw_size(struct si_shader *shader)
1981 {
1982 const struct si_shader_selector *sel = shader->selector;
1983
1984 if (sel->info.stage == MESA_SHADER_GEOMETRY && sel->so.num_outputs)
1985 return 44;
1986
1987 return 8;
1988 }
1989
1990 /**
1991 * Determine subgroup information like maximum number of vertices and prims.
1992 *
1993 * This happens before the shader is uploaded, since LDS relocations during
1994 * upload depend on the subgroup size.
1995 */
gfx10_ngg_calculate_subgroup_info(struct si_shader * shader)1996 bool gfx10_ngg_calculate_subgroup_info(struct si_shader *shader)
1997 {
1998 const struct si_shader_selector *gs_sel = shader->selector;
1999 const struct si_shader_selector *es_sel =
2000 shader->previous_stage_sel ? shader->previous_stage_sel : gs_sel;
2001 const gl_shader_stage gs_stage = gs_sel->info.stage;
2002 const unsigned gs_num_invocations = MAX2(gs_sel->info.base.gs.invocations, 1);
2003 const unsigned input_prim = si_get_input_prim(gs_sel, &shader->key);
2004 const bool use_adjacency =
2005 input_prim >= PIPE_PRIM_LINES_ADJACENCY && input_prim <= PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY;
2006 const unsigned max_verts_per_prim = u_vertices_per_prim(input_prim);
2007 const unsigned min_verts_per_prim = gs_stage == MESA_SHADER_GEOMETRY ? max_verts_per_prim : 1;
2008
2009 /* All these are in dwords: */
2010 /* GE can only use 8K dwords (32KB) of LDS per workgroup.
2011 */
2012 const unsigned max_lds_size = 8 * 1024 - gfx10_ngg_get_scratch_dw_size(shader);
2013 const unsigned target_lds_size = max_lds_size;
2014 unsigned esvert_lds_size = 0;
2015 unsigned gsprim_lds_size = 0;
2016
2017 /* All these are per subgroup: */
2018 const unsigned min_esverts = gs_sel->screen->info.chip_class >= GFX10_3 ? 29 : 24;
2019 bool max_vert_out_per_gs_instance = false;
2020 unsigned max_gsprims_base = gs_sel->screen->ngg_subgroup_size; /* default prim group size clamp */
2021 unsigned max_esverts_base = gs_sel->screen->ngg_subgroup_size;
2022
2023 if (gs_stage == MESA_SHADER_GEOMETRY) {
2024 bool force_multi_cycling = false;
2025 unsigned max_out_verts_per_gsprim = gs_sel->info.base.gs.vertices_out * gs_num_invocations;
2026
2027 retry_select_mode:
2028 if (max_out_verts_per_gsprim <= 256 && !force_multi_cycling) {
2029 if (max_out_verts_per_gsprim) {
2030 max_gsprims_base = MIN2(max_gsprims_base, 256 / max_out_verts_per_gsprim);
2031 }
2032 } else {
2033 /* Use special multi-cycling mode in which each GS
2034 * instance gets its own subgroup. Does not work with
2035 * tessellation. */
2036 max_vert_out_per_gs_instance = true;
2037 max_gsprims_base = 1;
2038 max_out_verts_per_gsprim = gs_sel->info.base.gs.vertices_out;
2039 }
2040
2041 esvert_lds_size = es_sel->esgs_itemsize / 4;
2042 gsprim_lds_size = (gs_sel->gsvs_vertex_size / 4 + 1) * max_out_verts_per_gsprim;
2043
2044 if (gsprim_lds_size > target_lds_size && !force_multi_cycling) {
2045 if (gs_sel->tess_turns_off_ngg || es_sel->info.stage != MESA_SHADER_TESS_EVAL) {
2046 force_multi_cycling = true;
2047 goto retry_select_mode;
2048 }
2049 }
2050 } else {
2051 /* VS and TES. */
2052 /* LDS size for passing data from ES to GS. */
2053 esvert_lds_size = ngg_nogs_vertex_size(shader);
2054 }
2055
2056 unsigned max_gsprims = max_gsprims_base;
2057 unsigned max_esverts = max_esverts_base;
2058
2059 if (esvert_lds_size)
2060 max_esverts = MIN2(max_esverts, target_lds_size / esvert_lds_size);
2061 if (gsprim_lds_size)
2062 max_gsprims = MIN2(max_gsprims, target_lds_size / gsprim_lds_size);
2063
2064 max_esverts = MIN2(max_esverts, max_gsprims * max_verts_per_prim);
2065 clamp_gsprims_to_esverts(&max_gsprims, max_esverts, min_verts_per_prim, use_adjacency);
2066 assert(max_esverts >= max_verts_per_prim && max_gsprims >= 1);
2067
2068 if (esvert_lds_size || gsprim_lds_size) {
2069 /* Now that we have a rough proportionality between esverts
2070 * and gsprims based on the primitive type, scale both of them
2071 * down simultaneously based on required LDS space.
2072 *
2073 * We could be smarter about this if we knew how much vertex
2074 * reuse to expect.
2075 */
2076 unsigned lds_total = max_esverts * esvert_lds_size + max_gsprims * gsprim_lds_size;
2077 if (lds_total > target_lds_size) {
2078 max_esverts = max_esverts * target_lds_size / lds_total;
2079 max_gsprims = max_gsprims * target_lds_size / lds_total;
2080
2081 max_esverts = MIN2(max_esverts, max_gsprims * max_verts_per_prim);
2082 clamp_gsprims_to_esverts(&max_gsprims, max_esverts, min_verts_per_prim, use_adjacency);
2083 assert(max_esverts >= max_verts_per_prim && max_gsprims >= 1);
2084 }
2085 }
2086
2087 /* Round up towards full wave sizes for better ALU utilization. */
2088 if (!max_vert_out_per_gs_instance) {
2089 const unsigned wavesize = si_get_shader_wave_size(shader);
2090 unsigned orig_max_esverts;
2091 unsigned orig_max_gsprims;
2092 do {
2093 orig_max_esverts = max_esverts;
2094 orig_max_gsprims = max_gsprims;
2095
2096 max_esverts = align(max_esverts, wavesize);
2097 max_esverts = MIN2(max_esverts, max_esverts_base);
2098 if (esvert_lds_size)
2099 max_esverts =
2100 MIN2(max_esverts, (max_lds_size - max_gsprims * gsprim_lds_size) / esvert_lds_size);
2101 max_esverts = MIN2(max_esverts, max_gsprims * max_verts_per_prim);
2102
2103 /* Hardware restriction: minimum value of max_esverts */
2104 if (gs_sel->screen->info.chip_class == GFX10)
2105 max_esverts = MAX2(max_esverts, min_esverts - 1 + max_verts_per_prim);
2106 else
2107 max_esverts = MAX2(max_esverts, min_esverts);
2108
2109 max_gsprims = align(max_gsprims, wavesize);
2110 max_gsprims = MIN2(max_gsprims, max_gsprims_base);
2111 if (gsprim_lds_size) {
2112 /* Don't count unusable vertices to the LDS size. Those are vertices above
2113 * the maximum number of vertices that can occur in the workgroup,
2114 * which is e.g. max_gsprims * 3 for triangles.
2115 */
2116 unsigned usable_esverts = MIN2(max_esverts, max_gsprims * max_verts_per_prim);
2117 max_gsprims =
2118 MIN2(max_gsprims, (max_lds_size - usable_esverts * esvert_lds_size) / gsprim_lds_size);
2119 }
2120 clamp_gsprims_to_esverts(&max_gsprims, max_esverts, min_verts_per_prim, use_adjacency);
2121 assert(max_esverts >= max_verts_per_prim && max_gsprims >= 1);
2122 } while (orig_max_esverts != max_esverts || orig_max_gsprims != max_gsprims);
2123
2124 /* Verify the restriction. */
2125 if (gs_sel->screen->info.chip_class == GFX10)
2126 assert(max_esverts >= min_esverts - 1 + max_verts_per_prim);
2127 else
2128 assert(max_esverts >= min_esverts);
2129 } else {
2130 /* Hardware restriction: minimum value of max_esverts */
2131 if (gs_sel->screen->info.chip_class == GFX10)
2132 max_esverts = MAX2(max_esverts, min_esverts - 1 + max_verts_per_prim);
2133 else
2134 max_esverts = MAX2(max_esverts, min_esverts);
2135 }
2136
2137 unsigned max_out_vertices =
2138 max_vert_out_per_gs_instance
2139 ? gs_sel->info.base.gs.vertices_out
2140 : gs_stage == MESA_SHADER_GEOMETRY
2141 ? max_gsprims * gs_num_invocations * gs_sel->info.base.gs.vertices_out
2142 : max_esverts;
2143 assert(max_out_vertices <= 256);
2144
2145 unsigned prim_amp_factor = 1;
2146 if (gs_stage == MESA_SHADER_GEOMETRY) {
2147 /* Number of output primitives per GS input primitive after
2148 * GS instancing. */
2149 prim_amp_factor = gs_sel->info.base.gs.vertices_out;
2150 }
2151
2152 shader->ngg.hw_max_esverts = max_esverts;
2153 shader->ngg.max_gsprims = max_gsprims;
2154 shader->ngg.max_out_verts = max_out_vertices;
2155 shader->ngg.prim_amp_factor = prim_amp_factor;
2156 shader->ngg.max_vert_out_per_gs_instance = max_vert_out_per_gs_instance;
2157
2158 /* Don't count unusable vertices. */
2159 shader->gs_info.esgs_ring_size = MIN2(max_esverts, max_gsprims * max_verts_per_prim) *
2160 esvert_lds_size;
2161 shader->ngg.ngg_emit_size = max_gsprims * gsprim_lds_size;
2162
2163 assert(shader->ngg.hw_max_esverts >= min_esverts); /* HW limitation */
2164
2165 /* If asserts are disabled, we use the same conditions to return false */
2166 return max_esverts >= max_verts_per_prim && max_gsprims >= 1 &&
2167 max_out_vertices <= 256 &&
2168 shader->ngg.hw_max_esverts >= min_esverts;
2169 }
2170