1 /*
2 * Copyright © 2015 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24 #include "brw_context.h"
25 #include "compiler/brw_nir.h"
26 #include "brw_program.h"
27 #include "compiler/glsl/gl_nir.h"
28 #include "compiler/glsl/gl_nir_linker.h"
29 #include "compiler/glsl/ir.h"
30 #include "compiler/glsl/ir_optimization.h"
31 #include "compiler/glsl/program.h"
32 #include "compiler/nir/nir_serialize.h"
33 #include "program/program.h"
34 #include "main/glspirv.h"
35 #include "main/mtypes.h"
36 #include "main/shaderapi.h"
37 #include "main/shaderobj.h"
38 #include "main/uniforms.h"
39
40 /**
41 * Performs a compile of the shader stages even when we don't know
42 * what non-orthogonal state will be set, in the hope that it reflects
43 * the eventual NOS used, and thus allows us to produce link failures.
44 */
45 static bool
brw_shader_precompile(struct gl_context * ctx,struct gl_shader_program * sh_prog)46 brw_shader_precompile(struct gl_context *ctx,
47 struct gl_shader_program *sh_prog)
48 {
49 struct gl_linked_shader *vs = sh_prog->_LinkedShaders[MESA_SHADER_VERTEX];
50 struct gl_linked_shader *tcs = sh_prog->_LinkedShaders[MESA_SHADER_TESS_CTRL];
51 struct gl_linked_shader *tes = sh_prog->_LinkedShaders[MESA_SHADER_TESS_EVAL];
52 struct gl_linked_shader *gs = sh_prog->_LinkedShaders[MESA_SHADER_GEOMETRY];
53 struct gl_linked_shader *fs = sh_prog->_LinkedShaders[MESA_SHADER_FRAGMENT];
54 struct gl_linked_shader *cs = sh_prog->_LinkedShaders[MESA_SHADER_COMPUTE];
55
56 if (fs && !brw_fs_precompile(ctx, fs->Program))
57 return false;
58
59 if (gs && !brw_gs_precompile(ctx, gs->Program))
60 return false;
61
62 if (tes && !brw_tes_precompile(ctx, sh_prog, tes->Program))
63 return false;
64
65 if (tcs && !brw_tcs_precompile(ctx, sh_prog, tcs->Program))
66 return false;
67
68 if (vs && !brw_vs_precompile(ctx, vs->Program))
69 return false;
70
71 if (cs && !brw_cs_precompile(ctx, cs->Program))
72 return false;
73
74 return true;
75 }
76
77 static void
brw_lower_packing_builtins(struct brw_context * brw,exec_list * ir)78 brw_lower_packing_builtins(struct brw_context *brw,
79 exec_list *ir)
80 {
81 const struct gen_device_info *devinfo = &brw->screen->devinfo;
82
83 /* Gens < 7 don't have instructions to convert to or from half-precision,
84 * and Gens < 6 don't expose that functionality.
85 */
86 if (devinfo->gen != 6)
87 return;
88
89 lower_packing_builtins(ir, LOWER_PACK_HALF_2x16 | LOWER_UNPACK_HALF_2x16);
90 }
91
92 static void
process_glsl_ir(struct brw_context * brw,struct gl_shader_program * shader_prog,struct gl_linked_shader * shader)93 process_glsl_ir(struct brw_context *brw,
94 struct gl_shader_program *shader_prog,
95 struct gl_linked_shader *shader)
96 {
97 const struct gen_device_info *devinfo = &brw->screen->devinfo;
98 struct gl_context *ctx = &brw->ctx;
99
100 /* Temporary memory context for any new IR. */
101 void *mem_ctx = ralloc_context(NULL);
102
103 ralloc_adopt(mem_ctx, shader->ir);
104
105 lower_blend_equation_advanced(
106 shader, ctx->Extensions.KHR_blend_equation_advanced_coherent);
107
108 /* lower_packing_builtins() inserts arithmetic instructions, so it
109 * must precede lower_instructions().
110 */
111 brw_lower_packing_builtins(brw, shader->ir);
112 do_mat_op_to_vec(shader->ir);
113
114 unsigned instructions_to_lower = (DIV_TO_MUL_RCP |
115 SUB_TO_ADD_NEG |
116 EXP_TO_EXP2 |
117 LOG_TO_LOG2 |
118 DFREXP_DLDEXP_TO_ARITH);
119 if (devinfo->gen < 7) {
120 instructions_to_lower |= BIT_COUNT_TO_MATH |
121 EXTRACT_TO_SHIFTS |
122 INSERT_TO_SHIFTS |
123 REVERSE_TO_SHIFTS;
124 }
125
126 lower_instructions(shader->ir, instructions_to_lower);
127
128 /* Pre-gen6 HW can only nest if-statements 16 deep. Beyond this,
129 * if-statements need to be flattened.
130 */
131 if (devinfo->gen < 6)
132 lower_if_to_cond_assign(shader->Stage, shader->ir, 16);
133
134 do_lower_texture_projection(shader->ir);
135 do_vec_index_to_cond_assign(shader->ir);
136 lower_vector_insert(shader->ir, true);
137 lower_offset_arrays(shader->ir);
138 lower_quadop_vector(shader->ir, false);
139
140 validate_ir_tree(shader->ir);
141
142 /* Now that we've finished altering the linked IR, reparent any live IR back
143 * to the permanent memory context, and free the temporary one (discarding any
144 * junk we optimized away).
145 */
146 reparent_ir(shader->ir, shader->ir);
147 ralloc_free(mem_ctx);
148
149 if (ctx->_Shader->Flags & GLSL_DUMP) {
150 fprintf(stderr, "\n");
151 if (shader->ir) {
152 fprintf(stderr, "GLSL IR for linked %s program %d:\n",
153 _mesa_shader_stage_to_string(shader->Stage),
154 shader_prog->Name);
155 _mesa_print_ir(stderr, shader->ir, NULL);
156 } else {
157 fprintf(stderr, "No GLSL IR for linked %s program %d (shader may be "
158 "from cache)\n", _mesa_shader_stage_to_string(shader->Stage),
159 shader_prog->Name);
160 }
161 fprintf(stderr, "\n");
162 }
163 }
164
165 static void
unify_interfaces(struct shader_info ** infos)166 unify_interfaces(struct shader_info **infos)
167 {
168 struct shader_info *prev_info = NULL;
169
170 for (unsigned i = MESA_SHADER_VERTEX; i < MESA_SHADER_FRAGMENT; i++) {
171 if (!infos[i])
172 continue;
173
174 if (prev_info) {
175 prev_info->outputs_written |= infos[i]->inputs_read &
176 ~(VARYING_BIT_TESS_LEVEL_INNER | VARYING_BIT_TESS_LEVEL_OUTER);
177 infos[i]->inputs_read |= prev_info->outputs_written &
178 ~(VARYING_BIT_TESS_LEVEL_INNER | VARYING_BIT_TESS_LEVEL_OUTER);
179
180 prev_info->patch_outputs_written |= infos[i]->patch_inputs_read;
181 infos[i]->patch_inputs_read |= prev_info->patch_outputs_written;
182 }
183 prev_info = infos[i];
184 }
185 }
186
187 static void
update_xfb_info(struct gl_transform_feedback_info * xfb_info,struct shader_info * info)188 update_xfb_info(struct gl_transform_feedback_info *xfb_info,
189 struct shader_info *info)
190 {
191 if (!xfb_info)
192 return;
193
194 for (unsigned i = 0; i < xfb_info->NumOutputs; i++) {
195 struct gl_transform_feedback_output *output = &xfb_info->Outputs[i];
196
197 /* The VUE header contains three scalar fields packed together:
198 * - gl_PointSize is stored in VARYING_SLOT_PSIZ.w
199 * - gl_Layer is stored in VARYING_SLOT_PSIZ.y
200 * - gl_ViewportIndex is stored in VARYING_SLOT_PSIZ.z
201 */
202 switch (output->OutputRegister) {
203 case VARYING_SLOT_LAYER:
204 assert(output->NumComponents == 1);
205 output->OutputRegister = VARYING_SLOT_PSIZ;
206 output->ComponentOffset = 1;
207 break;
208 case VARYING_SLOT_VIEWPORT:
209 assert(output->NumComponents == 1);
210 output->OutputRegister = VARYING_SLOT_PSIZ;
211 output->ComponentOffset = 2;
212 break;
213 case VARYING_SLOT_PSIZ:
214 assert(output->NumComponents == 1);
215 output->ComponentOffset = 3;
216 break;
217 }
218
219 info->outputs_written |= 1ull << output->OutputRegister;
220 }
221 }
222
223 extern "C" GLboolean
brw_link_shader(struct gl_context * ctx,struct gl_shader_program * shProg)224 brw_link_shader(struct gl_context *ctx, struct gl_shader_program *shProg)
225 {
226 struct brw_context *brw = brw_context(ctx);
227 const struct brw_compiler *compiler = brw->screen->compiler;
228 unsigned int stage;
229 struct shader_info *infos[MESA_SHADER_STAGES] = { 0, };
230
231 if (shProg->data->LinkStatus == LINKING_SKIPPED)
232 return GL_TRUE;
233
234 for (stage = 0; stage < ARRAY_SIZE(shProg->_LinkedShaders); stage++) {
235 struct gl_linked_shader *shader = shProg->_LinkedShaders[stage];
236 if (!shader)
237 continue;
238
239 struct gl_program *prog = shader->Program;
240 prog->Parameters = _mesa_new_parameter_list();
241
242 if (!shader->spirv_data)
243 process_glsl_ir(brw, shProg, shader);
244
245 _mesa_copy_linked_program_data(shProg, shader);
246
247 prog->ShadowSamplers = shader->shadow_samplers;
248
249 bool debug_enabled =
250 (INTEL_DEBUG & intel_debug_flag_for_shader_stage(shader->Stage));
251
252 if (debug_enabled && shader->ir) {
253 fprintf(stderr, "GLSL IR for native %s shader %d:\n",
254 _mesa_shader_stage_to_string(shader->Stage), shProg->Name);
255 _mesa_print_ir(stderr, shader->ir, NULL);
256 fprintf(stderr, "\n\n");
257 }
258
259 prog->nir = brw_create_nir(brw, shProg, prog, (gl_shader_stage) stage,
260 compiler->scalar_stage[stage]);
261 }
262
263 /* TODO: Verify if its feasible to split up the NIR linking work into a
264 * per-stage part (that fill out information we need for the passes) and a
265 * actual linking part, so that we could fold back brw_nir_lower_resources
266 * back into brw_create_nir.
267 */
268
269 /* SPIR-V programs use a NIR linker */
270 if (shProg->data->spirv) {
271 static const gl_nir_linker_options opts = {
272 .fill_parameters = false,
273 };
274 if (!gl_nir_link_spirv(ctx, shProg, &opts))
275 return GL_FALSE;
276 }
277
278 for (stage = 0; stage < ARRAY_SIZE(shProg->_LinkedShaders); stage++) {
279 struct gl_linked_shader *shader = shProg->_LinkedShaders[stage];
280 if (!shader)
281 continue;
282
283 struct gl_program *prog = shader->Program;
284
285 brw_nir_lower_resources(prog->nir, shProg, prog, &brw->screen->devinfo);
286
287 NIR_PASS_V(prog->nir, brw_nir_lower_gl_images, prog);
288 }
289
290 /* Determine first and last stage. */
291 unsigned first = MESA_SHADER_STAGES;
292 unsigned last = 0;
293 for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
294 if (!shProg->_LinkedShaders[i])
295 continue;
296 if (first == MESA_SHADER_STAGES)
297 first = i;
298 last = i;
299 }
300
301 /* Linking the stages in the opposite order (from fragment to vertex)
302 * ensures that inter-shader outputs written to in an earlier stage
303 * are eliminated if they are (transitively) not used in a later
304 * stage.
305 *
306 * TODO: Look into Shadow of Mordor regressions on HSW and enable this for
307 * all platforms. See: https://bugs.freedesktop.org/show_bug.cgi?id=103537
308 */
309 if (first != last && brw->screen->devinfo.gen >= 8) {
310 int next = last;
311 for (int i = next - 1; i >= 0; i--) {
312 if (shProg->_LinkedShaders[i] == NULL)
313 continue;
314
315 brw_nir_link_shaders(compiler,
316 shProg->_LinkedShaders[i]->Program->nir,
317 shProg->_LinkedShaders[next]->Program->nir);
318 next = i;
319 }
320 }
321
322 for (stage = 0; stage < ARRAY_SIZE(shProg->_LinkedShaders); stage++) {
323 struct gl_linked_shader *shader = shProg->_LinkedShaders[stage];
324 if (!shader)
325 continue;
326
327 struct gl_program *prog = shader->Program;
328
329 _mesa_update_shader_textures_used(shProg, prog);
330
331 brw_shader_gather_info(prog->nir, prog);
332
333 NIR_PASS_V(prog->nir, gl_nir_lower_atomics, shProg, false);
334 NIR_PASS_V(prog->nir, nir_lower_atomics_to_ssbo);
335
336 nir_sweep(prog->nir);
337
338 infos[stage] = &prog->nir->info;
339
340 update_xfb_info(prog->sh.LinkedTransformFeedback, infos[stage]);
341
342 /* Make a pass over the IR to add state references for any built-in
343 * uniforms that are used. This has to be done now (during linking).
344 * Code generation doesn't happen until the first time this shader is
345 * used for rendering. Waiting until then to generate the parameters is
346 * too late. At that point, the values for the built-in uniforms won't
347 * get sent to the shader.
348 */
349 nir_foreach_uniform_variable(var, prog->nir) {
350 const nir_state_slot *const slots = var->state_slots;
351 for (unsigned int i = 0; i < var->num_state_slots; i++) {
352 assert(slots != NULL);
353 _mesa_add_state_reference(prog->Parameters, slots[i].tokens);
354 }
355 }
356 }
357
358 /* The linker tries to dead code eliminate unused varying components,
359 * and make sure interfaces match. But it isn't able to do so in all
360 * cases. So, explicitly make the interfaces match by OR'ing together
361 * the inputs_read/outputs_written bitfields of adjacent stages.
362 */
363 if (!shProg->SeparateShader)
364 unify_interfaces(infos);
365
366 if ((ctx->_Shader->Flags & GLSL_DUMP) && shProg->Name != 0) {
367 for (unsigned i = 0; i < shProg->NumShaders; i++) {
368 const struct gl_shader *sh = shProg->Shaders[i];
369 if (!sh)
370 continue;
371
372 fprintf(stderr, "GLSL %s shader %d source for linked program %d:\n",
373 _mesa_shader_stage_to_string(sh->Stage),
374 i, shProg->Name);
375 fprintf(stderr, "%s", sh->Source);
376 fprintf(stderr, "\n");
377 }
378 }
379
380 if (brw->precompile && !brw_shader_precompile(ctx, shProg))
381 return GL_FALSE;
382
383 /* SPIR-V programs build its resource list from linked NIR shaders. */
384 if (!shProg->data->spirv)
385 build_program_resource_list(ctx, shProg, false);
386 else
387 nir_build_program_resource_list(ctx, shProg, true);
388
389 for (stage = 0; stage < ARRAY_SIZE(shProg->_LinkedShaders); stage++) {
390 struct gl_linked_shader *shader = shProg->_LinkedShaders[stage];
391 if (!shader)
392 continue;
393
394 /* The GLSL IR won't be needed anymore. */
395 ralloc_free(shader->ir);
396 shader->ir = NULL;
397 }
398
399 return GL_TRUE;
400 }
401