Bug Summary

File:root/firefox-clang/third_party/rust/glslopt/glsl-optimizer/src/compiler/glsl/link_varyings.cpp
Warning:line 2777, column 7
Access to field 'ir' results in a dereference of a null pointer (loaded from variable 'consumer')

Annotated Source Code

Press '?' to see keyboard shortcuts

clang -cc1 -cc1 -triple x86_64-unknown-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name link_varyings.cpp -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -fhalf-no-semantic-interposition -mframe-pointer=all -relaxed-aliasing -ffp-contract=off -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fdebug-compilation-dir=/root/firefox-clang/third_party/rust/glslopt -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/root/firefox-clang/third_party/rust/glslopt -resource-dir /usr/lib/llvm-21/lib/clang/21 -include /root/firefox-clang/config/gcc_hidden.h -include /root/firefox-clang/obj-x86_64-pc-linux-gnu/mozilla-config.h -I glsl-optimizer/include -I glsl-optimizer/src/mesa -I glsl-optimizer/src/mapi -I glsl-optimizer/src/compiler -I glsl-optimizer/src/compiler/glsl -I glsl-optimizer/src/gallium/auxiliary -I glsl-optimizer/src/gallium/include -I glsl-optimizer/src -I glsl-optimizer/src/util -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/dist/stl_wrappers -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/dist/system_wrappers -U _FORTIFY_SOURCE -D _FORTIFY_SOURCE=2 -D _GLIBCXX_ASSERTIONS -D DEBUG=1 -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/dist/include -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/dist/include/nspr -I /root/firefox-clang/obj-x86_64-pc-linux-gnu/dist/include/nss -D MOZILLA_CLIENT -D MOZILLA_CONFIG_H -D __STDC_FORMAT_MACROS -D _GNU_SOURCE -D HAVE_ENDIAN_H -D HAVE_PTHREAD -D HAVE_TIMESPEC_GET -D MOZ_INCLUDE_MOZALLOC_H -D mozilla_throw_gcc_h -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/14/../../../../include/x86_64-linux-gnu/c++/14 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/14/../../../../include/c++/14/backward -internal-isystem /usr/lib/llvm-21/lib/clang/21/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/14/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-error=pessimizing-move -Wno-error=large-by-value-copy=128 -Wno-error=implicit-int-float-conversion -Wno-error=thread-safety-analysis -Wno-error=tautological-type-limit-compare -Wno-invalid-offsetof -Wno-range-loop-analysis -Wno-deprecated-anon-enum-enum-conversion -Wno-deprecated-enum-enum-conversion -Wno-deprecated-this-capture -Wno-inline-new-delete -Wno-error=deprecated-declarations -Wno-error=array-bounds -Wno-error=free-nonheap-object -Wno-error=atomic-alignment -Wno-error=deprecated-builtins -Wno-psabi -Wno-error=builtin-macro-redefined -Wno-vla-cxx-extension -Wno-unknown-warning-option -fdeprecated-macro -ferror-limit 19 -fstrict-flex-arrays=1 -stack-protector 2 -fstack-clash-protection -ftrivial-auto-var-init=pattern -fno-rtti -fgnuc-version=4.2.1 -fskip-odr-check-in-gmf -fno-sized-deallocation -fno-aligned-allocation -vectorize-loops -vectorize-slp -analyzer-checker optin.performance.Padding -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2025-06-30-093548-1913035-1 -x c++ glsl-optimizer/src/compiler/glsl/link_varyings.cpp
1/*
2 * Copyright © 2012 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 */
23
24/**
25 * \file link_varyings.cpp
26 *
27 * Linker functions related specifically to linking varyings between shader
28 * stages.
29 */
30
31
32#include "main/errors.h"
33#include "main/mtypes.h"
34#include "glsl_symbol_table.h"
35#include "glsl_parser_extras.h"
36#include "ir_optimization.h"
37#include "linker.h"
38#include "link_varyings.h"
39#include "main/macros.h"
40#include "util/hash_table.h"
41#include "util/u_math.h"
42#include "program.h"
43
44
45/**
46 * Get the varying type stripped of the outermost array if we're processing
47 * a stage whose varyings are arrays indexed by a vertex number (such as
48 * geometry shader inputs).
49 */
50static const glsl_type *
51get_varying_type(const ir_variable *var, gl_shader_stage stage)
52{
53 const glsl_type *type = var->type;
54
55 if (!var->data.patch &&
56 ((var->data.mode == ir_var_shader_out &&
57 stage == MESA_SHADER_TESS_CTRL) ||
58 (var->data.mode == ir_var_shader_in &&
59 (stage == MESA_SHADER_TESS_CTRL || stage == MESA_SHADER_TESS_EVAL ||
60 stage == MESA_SHADER_GEOMETRY)))) {
61 assert(type->is_array())(static_cast <bool> (type->is_array()) ? void (0) : __assert_fail
("type->is_array()", __builtin_FILE (), __builtin_LINE ()
, __extension__ __PRETTY_FUNCTION__));
62 type = type->fields.array;
63 }
64
65 return type;
66}
67
68static void
69create_xfb_varying_names(void *mem_ctx, const glsl_type *t, char **name,
70 size_t name_length, unsigned *count,
71 const char *ifc_member_name,
72 const glsl_type *ifc_member_t, char ***varying_names)
73{
74 if (t->is_interface()) {
75 size_t new_length = name_length;
76
77 assert(ifc_member_name && ifc_member_t)(static_cast <bool> (ifc_member_name && ifc_member_t
) ? void (0) : __assert_fail ("ifc_member_name && ifc_member_t"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
78 ralloc_asprintf_rewrite_tail(name, &new_length, ".%s", ifc_member_name);
79
80 create_xfb_varying_names(mem_ctx, ifc_member_t, name, new_length, count,
81 NULL__null, NULL__null, varying_names);
82 } else if (t->is_struct()) {
83 for (unsigned i = 0; i < t->length; i++) {
84 const char *field = t->fields.structure[i].name;
85 size_t new_length = name_length;
86
87 ralloc_asprintf_rewrite_tail(name, &new_length, ".%s", field);
88
89 create_xfb_varying_names(mem_ctx, t->fields.structure[i].type, name,
90 new_length, count, NULL__null, NULL__null,
91 varying_names);
92 }
93 } else if (t->without_array()->is_struct() ||
94 t->without_array()->is_interface() ||
95 (t->is_array() && t->fields.array->is_array())) {
96 for (unsigned i = 0; i < t->length; i++) {
97 size_t new_length = name_length;
98
99 /* Append the subscript to the current variable name */
100 ralloc_asprintf_rewrite_tail(name, &new_length, "[%u]", i);
101
102 create_xfb_varying_names(mem_ctx, t->fields.array, name, new_length,
103 count, ifc_member_name, ifc_member_t,
104 varying_names);
105 }
106 } else {
107 (*varying_names)[(*count)++] = ralloc_strdup(mem_ctx, *name);
108 }
109}
110
111static bool
112process_xfb_layout_qualifiers(void *mem_ctx, const gl_linked_shader *sh,
113 struct gl_shader_program *prog,
114 unsigned *num_tfeedback_decls,
115 char ***varying_names)
116{
117 bool has_xfb_qualifiers = false;
118
119 /* We still need to enable transform feedback mode even if xfb_stride is
120 * only applied to a global out. Also we don't bother to propagate
121 * xfb_stride to interface block members so this will catch that case also.
122 */
123 for (unsigned j = 0; j < MAX_FEEDBACK_BUFFERS4; j++) {
124 if (prog->TransformFeedback.BufferStride[j]) {
125 has_xfb_qualifiers = true;
126 break;
127 }
128 }
129
130 foreach_in_list(ir_instruction, node, sh->ir)for (ir_instruction *node = (!exec_node_is_tail_sentinel((sh->
ir)->head_sentinel.next) ? (ir_instruction *) ((sh->ir)
->head_sentinel.next) : __null); (node) != __null; (node) =
(!exec_node_is_tail_sentinel((node)->next) ? (ir_instruction
*) ((node)->next) : __null)) {
131 ir_variable *var = node->as_variable();
132 if (!var || var->data.mode != ir_var_shader_out)
133 continue;
134
135 /* From the ARB_enhanced_layouts spec:
136 *
137 * "Any shader making any static use (after preprocessing) of any of
138 * these *xfb_* qualifiers will cause the shader to be in a
139 * transform feedback capturing mode and hence responsible for
140 * describing the transform feedback setup. This mode will capture
141 * any output selected by *xfb_offset*, directly or indirectly, to
142 * a transform feedback buffer."
143 */
144 if (var->data.explicit_xfb_buffer || var->data.explicit_xfb_stride) {
145 has_xfb_qualifiers = true;
146 }
147
148 if (var->data.explicit_xfb_offset) {
149 *num_tfeedback_decls += var->type->varying_count();
150 has_xfb_qualifiers = true;
151 }
152 }
153
154 if (*num_tfeedback_decls == 0)
155 return has_xfb_qualifiers;
156
157 unsigned i = 0;
158 *varying_names = ralloc_array(mem_ctx, char *, *num_tfeedback_decls)((char * *) ralloc_array_size(mem_ctx, sizeof(char *), *num_tfeedback_decls
));
159 foreach_in_list(ir_instruction, node, sh->ir)for (ir_instruction *node = (!exec_node_is_tail_sentinel((sh->
ir)->head_sentinel.next) ? (ir_instruction *) ((sh->ir)
->head_sentinel.next) : __null); (node) != __null; (node) =
(!exec_node_is_tail_sentinel((node)->next) ? (ir_instruction
*) ((node)->next) : __null)) {
160 ir_variable *var = node->as_variable();
161 if (!var || var->data.mode != ir_var_shader_out)
162 continue;
163
164 if (var->data.explicit_xfb_offset) {
165 char *name;
166 const glsl_type *type, *member_type;
167
168 if (var->data.from_named_ifc_block) {
169 type = var->get_interface_type();
170
171 /* Find the member type before it was altered by lowering */
172 const glsl_type *type_wa = type->without_array();
173 member_type =
174 type_wa->fields.structure[type_wa->field_index(var->name)].type;
175 name = ralloc_strdup(NULL__null, type_wa->name);
176 } else {
177 type = var->type;
178 member_type = NULL__null;
179 name = ralloc_strdup(NULL__null, var->name);
180 }
181 create_xfb_varying_names(mem_ctx, type, &name, strlen(name), &i,
182 var->name, member_type, varying_names);
183 ralloc_free(name);
184 }
185 }
186
187 assert(i == *num_tfeedback_decls)(static_cast <bool> (i == *num_tfeedback_decls) ? void (
0) : __assert_fail ("i == *num_tfeedback_decls", __builtin_FILE
(), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__));
188 return has_xfb_qualifiers;
189}
190
191/**
192 * Validate the types and qualifiers of an output from one stage against the
193 * matching input to another stage.
194 */
195static void
196cross_validate_types_and_qualifiers(struct gl_context *ctx,
197 struct gl_shader_program *prog,
198 const ir_variable *input,
199 const ir_variable *output,
200 gl_shader_stage consumer_stage,
201 gl_shader_stage producer_stage)
202{
203 /* Check that the types match between stages.
204 */
205 const glsl_type *type_to_match = input->type;
206
207 /* VS -> GS, VS -> TCS, VS -> TES, TES -> GS */
208 const bool extra_array_level = (producer_stage == MESA_SHADER_VERTEX &&
209 consumer_stage != MESA_SHADER_FRAGMENT) ||
210 consumer_stage == MESA_SHADER_GEOMETRY;
211 if (extra_array_level) {
212 assert(type_to_match->is_array())(static_cast <bool> (type_to_match->is_array()) ? void
(0) : __assert_fail ("type_to_match->is_array()", __builtin_FILE
(), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__));
213 type_to_match = type_to_match->fields.array;
214 }
215
216 if (type_to_match != output->type) {
217 if (output->type->is_struct()) {
218 /* Structures across shader stages can have different name
219 * and considered to match in type if and only if structure
220 * members match in name, type, qualification, and declaration
221 * order. The precision doesn’t need to match.
222 */
223 if (!output->type->record_compare(type_to_match,
224 false, /* match_name */
225 true, /* match_locations */
226 false /* match_precision */)) {
227 linker_error(prog,
228 "%s shader output `%s' declared as struct `%s', "
229 "doesn't match in type with %s shader input "
230 "declared as struct `%s'\n",
231 _mesa_shader_stage_to_string(producer_stage),
232 output->name,
233 output->type->name,
234 _mesa_shader_stage_to_string(consumer_stage),
235 input->type->name);
236 }
237 } else if (!output->type->is_array() || !is_gl_identifier(output->name)) {
238 /* There is a bit of a special case for gl_TexCoord. This
239 * built-in is unsized by default. Applications that variable
240 * access it must redeclare it with a size. There is some
241 * language in the GLSL spec that implies the fragment shader
242 * and vertex shader do not have to agree on this size. Other
243 * driver behave this way, and one or two applications seem to
244 * rely on it.
245 *
246 * Neither declaration needs to be modified here because the array
247 * sizes are fixed later when update_array_sizes is called.
248 *
249 * From page 48 (page 54 of the PDF) of the GLSL 1.10 spec:
250 *
251 * "Unlike user-defined varying variables, the built-in
252 * varying variables don't have a strict one-to-one
253 * correspondence between the vertex language and the
254 * fragment language."
255 */
256 linker_error(prog,
257 "%s shader output `%s' declared as type `%s', "
258 "but %s shader input declared as type `%s'\n",
259 _mesa_shader_stage_to_string(producer_stage),
260 output->name,
261 output->type->name,
262 _mesa_shader_stage_to_string(consumer_stage),
263 input->type->name);
264 return;
265 }
266 }
267
268 /* Check that all of the qualifiers match between stages.
269 */
270
271 /* According to the OpenGL and OpenGLES GLSL specs, the centroid qualifier
272 * should match until OpenGL 4.3 and OpenGLES 3.1. The OpenGLES 3.0
273 * conformance test suite does not verify that the qualifiers must match.
274 * The deqp test suite expects the opposite (OpenGLES 3.1) behavior for
275 * OpenGLES 3.0 drivers, so we relax the checking in all cases.
276 */
277 if (false /* always skip the centroid check */ &&
278 prog->data->Version < (prog->IsES ? 310 : 430) &&
279 input->data.centroid != output->data.centroid) {
280 linker_error(prog,
281 "%s shader output `%s' %s centroid qualifier, "
282 "but %s shader input %s centroid qualifier\n",
283 _mesa_shader_stage_to_string(producer_stage),
284 output->name,
285 (output->data.centroid) ? "has" : "lacks",
286 _mesa_shader_stage_to_string(consumer_stage),
287 (input->data.centroid) ? "has" : "lacks");
288 return;
289 }
290
291 if (input->data.sample != output->data.sample) {
292 linker_error(prog,
293 "%s shader output `%s' %s sample qualifier, "
294 "but %s shader input %s sample qualifier\n",
295 _mesa_shader_stage_to_string(producer_stage),
296 output->name,
297 (output->data.sample) ? "has" : "lacks",
298 _mesa_shader_stage_to_string(consumer_stage),
299 (input->data.sample) ? "has" : "lacks");
300 return;
301 }
302
303 if (input->data.patch != output->data.patch) {
304 linker_error(prog,
305 "%s shader output `%s' %s patch qualifier, "
306 "but %s shader input %s patch qualifier\n",
307 _mesa_shader_stage_to_string(producer_stage),
308 output->name,
309 (output->data.patch) ? "has" : "lacks",
310 _mesa_shader_stage_to_string(consumer_stage),
311 (input->data.patch) ? "has" : "lacks");
312 return;
313 }
314
315 /* The GLSL 4.30 and GLSL ES 3.00 specifications say:
316 *
317 * "As only outputs need be declared with invariant, an output from
318 * one shader stage will still match an input of a subsequent stage
319 * without the input being declared as invariant."
320 *
321 * while GLSL 4.20 says:
322 *
323 * "For variables leaving one shader and coming into another shader,
324 * the invariant keyword has to be used in both shaders, or a link
325 * error will result."
326 *
327 * and GLSL ES 1.00 section 4.6.4 "Invariance and Linking" says:
328 *
329 * "The invariance of varyings that are declared in both the vertex
330 * and fragment shaders must match."
331 */
332 if (input->data.explicit_invariant != output->data.explicit_invariant &&
333 prog->data->Version < (prog->IsES ? 300 : 430)) {
334 linker_error(prog,
335 "%s shader output `%s' %s invariant qualifier, "
336 "but %s shader input %s invariant qualifier\n",
337 _mesa_shader_stage_to_string(producer_stage),
338 output->name,
339 (output->data.explicit_invariant) ? "has" : "lacks",
340 _mesa_shader_stage_to_string(consumer_stage),
341 (input->data.explicit_invariant) ? "has" : "lacks");
342 return;
343 }
344
345 /* GLSL >= 4.40 removes text requiring interpolation qualifiers
346 * to match cross stage, they must only match within the same stage.
347 *
348 * From page 84 (page 90 of the PDF) of the GLSL 4.40 spec:
349 *
350 * "It is a link-time error if, within the same stage, the interpolation
351 * qualifiers of variables of the same name do not match.
352 *
353 * Section 4.3.9 (Interpolation) of the GLSL ES 3.00 spec says:
354 *
355 * "When no interpolation qualifier is present, smooth interpolation
356 * is used."
357 *
358 * So we match variables where one is smooth and the other has no explicit
359 * qualifier.
360 */
361 unsigned input_interpolation = input->data.interpolation;
362 unsigned output_interpolation = output->data.interpolation;
363 if (prog->IsES) {
364 if (input_interpolation == INTERP_MODE_NONE)
365 input_interpolation = INTERP_MODE_SMOOTH;
366 if (output_interpolation == INTERP_MODE_NONE)
367 output_interpolation = INTERP_MODE_SMOOTH;
368 }
369 if (input_interpolation != output_interpolation &&
370 prog->data->Version < 440) {
371 if (!ctx->Const.AllowGLSLCrossStageInterpolationMismatch) {
372 linker_error(prog,
373 "%s shader output `%s' specifies %s "
374 "interpolation qualifier, "
375 "but %s shader input specifies %s "
376 "interpolation qualifier\n",
377 _mesa_shader_stage_to_string(producer_stage),
378 output->name,
379 interpolation_string(output->data.interpolation),
380 _mesa_shader_stage_to_string(consumer_stage),
381 interpolation_string(input->data.interpolation));
382 return;
383 } else {
384 linker_warning(prog,
385 "%s shader output `%s' specifies %s "
386 "interpolation qualifier, "
387 "but %s shader input specifies %s "
388 "interpolation qualifier\n",
389 _mesa_shader_stage_to_string(producer_stage),
390 output->name,
391 interpolation_string(output->data.interpolation),
392 _mesa_shader_stage_to_string(consumer_stage),
393 interpolation_string(input->data.interpolation));
394 }
395 }
396}
397
398/**
399 * Validate front and back color outputs against single color input
400 */
401static void
402cross_validate_front_and_back_color(struct gl_context *ctx,
403 struct gl_shader_program *prog,
404 const ir_variable *input,
405 const ir_variable *front_color,
406 const ir_variable *back_color,
407 gl_shader_stage consumer_stage,
408 gl_shader_stage producer_stage)
409{
410 if (front_color != NULL__null && front_color->data.assigned)
411 cross_validate_types_and_qualifiers(ctx, prog, input, front_color,
412 consumer_stage, producer_stage);
413
414 if (back_color != NULL__null && back_color->data.assigned)
415 cross_validate_types_and_qualifiers(ctx, prog, input, back_color,
416 consumer_stage, producer_stage);
417}
418
419static unsigned
420compute_variable_location_slot(ir_variable *var, gl_shader_stage stage)
421{
422 unsigned location_start = VARYING_SLOT_VAR0;
423
424 switch (stage) {
425 case MESA_SHADER_VERTEX:
426 if (var->data.mode == ir_var_shader_in)
427 location_start = VERT_ATTRIB_GENERIC0;
428 break;
429 case MESA_SHADER_TESS_CTRL:
430 case MESA_SHADER_TESS_EVAL:
431 if (var->data.patch)
432 location_start = VARYING_SLOT_PATCH0((VARYING_SLOT_VAR0 + 32));
433 break;
434 case MESA_SHADER_FRAGMENT:
435 if (var->data.mode == ir_var_shader_out)
436 location_start = FRAG_RESULT_DATA0;
437 break;
438 default:
439 break;
440 }
441
442 return var->data.location - location_start;
443}
444
445struct explicit_location_info {
446 ir_variable *var;
447 bool base_type_is_integer;
448 unsigned base_type_bit_size;
449 unsigned interpolation;
450 bool centroid;
451 bool sample;
452 bool patch;
453};
454
455static bool
456check_location_aliasing(struct explicit_location_info explicit_locations[][4],
457 ir_variable *var,
458 unsigned location,
459 unsigned component,
460 unsigned location_limit,
461 const glsl_type *type,
462 unsigned interpolation,
463 bool centroid,
464 bool sample,
465 bool patch,
466 gl_shader_program *prog,
467 gl_shader_stage stage)
468{
469 unsigned last_comp;
470 unsigned base_type_bit_size;
471 const glsl_type *type_without_array = type->without_array();
472 const bool base_type_is_integer =
473 glsl_base_type_is_integer(type_without_array->base_type);
474 const bool is_struct = type_without_array->is_struct();
475 if (is_struct) {
476 /* structs don't have a defined underlying base type so just treat all
477 * component slots as used and set the bit size to 0. If there is
478 * location aliasing, we'll fail anyway later.
479 */
480 last_comp = 4;
481 base_type_bit_size = 0;
482 } else {
483 unsigned dmul = type_without_array->is_64bit() ? 2 : 1;
484 last_comp = component + type_without_array->vector_elements * dmul;
485 base_type_bit_size =
486 glsl_base_type_get_bit_size(type_without_array->base_type);
487 }
488
489 while (location < location_limit) {
490 unsigned comp = 0;
491 while (comp < 4) {
492 struct explicit_location_info *info =
493 &explicit_locations[location][comp];
494
495 if (info->var) {
496 if (info->var->type->without_array()->is_struct() || is_struct) {
497 /* Structs cannot share location since they are incompatible
498 * with any other underlying numerical type.
499 */
500 linker_error(prog,
501 "%s shader has multiple %sputs sharing the "
502 "same location that don't have the same "
503 "underlying numerical type. Struct variable '%s', "
504 "location %u\n",
505 _mesa_shader_stage_to_string(stage),
506 var->data.mode == ir_var_shader_in ? "in" : "out",
507 is_struct ? var->name : info->var->name,
508 location);
509 return false;
510 } else if (comp >= component && comp < last_comp) {
511 /* Component aliasing is not allowed */
512 linker_error(prog,
513 "%s shader has multiple %sputs explicitly "
514 "assigned to location %d and component %d\n",
515 _mesa_shader_stage_to_string(stage),
516 var->data.mode == ir_var_shader_in ? "in" : "out",
517 location, comp);
518 return false;
519 } else {
520 /* From the OpenGL 4.60.5 spec, section 4.4.1 Input Layout
521 * Qualifiers, Page 67, (Location aliasing):
522 *
523 * " Further, when location aliasing, the aliases sharing the
524 * location must have the same underlying numerical type
525 * and bit width (floating-point or integer, 32-bit versus
526 * 64-bit, etc.) and the same auxiliary storage and
527 * interpolation qualification."
528 */
529
530 /* If the underlying numerical type isn't integer, implicitly
531 * it will be float or else we would have failed by now.
532 */
533 if (info->base_type_is_integer != base_type_is_integer) {
534 linker_error(prog,
535 "%s shader has multiple %sputs sharing the "
536 "same location that don't have the same "
537 "underlying numerical type. Location %u "
538 "component %u.\n",
539 _mesa_shader_stage_to_string(stage),
540 var->data.mode == ir_var_shader_in ?
541 "in" : "out", location, comp);
542 return false;
543 }
544
545 if (info->base_type_bit_size != base_type_bit_size) {
546 linker_error(prog,
547 "%s shader has multiple %sputs sharing the "
548 "same location that don't have the same "
549 "underlying numerical bit size. Location %u "
550 "component %u.\n",
551 _mesa_shader_stage_to_string(stage),
552 var->data.mode == ir_var_shader_in ?
553 "in" : "out", location, comp);
554 return false;
555 }
556
557 if (info->interpolation != interpolation) {
558 linker_error(prog,
559 "%s shader has multiple %sputs sharing the "
560 "same location that don't have the same "
561 "interpolation qualification. Location %u "
562 "component %u.\n",
563 _mesa_shader_stage_to_string(stage),
564 var->data.mode == ir_var_shader_in ?
565 "in" : "out", location, comp);
566 return false;
567 }
568
569 if (info->centroid != centroid ||
570 info->sample != sample ||
571 info->patch != patch) {
572 linker_error(prog,
573 "%s shader has multiple %sputs sharing the "
574 "same location that don't have the same "
575 "auxiliary storage qualification. Location %u "
576 "component %u.\n",
577 _mesa_shader_stage_to_string(stage),
578 var->data.mode == ir_var_shader_in ?
579 "in" : "out", location, comp);
580 return false;
581 }
582 }
583 } else if (comp >= component && comp < last_comp) {
584 info->var = var;
585 info->base_type_is_integer = base_type_is_integer;
586 info->base_type_bit_size = base_type_bit_size;
587 info->interpolation = interpolation;
588 info->centroid = centroid;
589 info->sample = sample;
590 info->patch = patch;
591 }
592
593 comp++;
594
595 /* We need to do some special handling for doubles as dvec3 and
596 * dvec4 consume two consecutive locations. We don't need to
597 * worry about components beginning at anything other than 0 as
598 * the spec does not allow this for dvec3 and dvec4.
599 */
600 if (comp == 4 && last_comp > 4) {
601 last_comp = last_comp - 4;
602 /* Bump location index and reset the component index */
603 location++;
604 comp = 0;
605 component = 0;
606 }
607 }
608
609 location++;
610 }
611
612 return true;
613}
614
615static bool
616validate_explicit_variable_location(struct gl_context *ctx,
617 struct explicit_location_info explicit_locations[][4],
618 ir_variable *var,
619 gl_shader_program *prog,
620 gl_linked_shader *sh)
621{
622 const glsl_type *type = get_varying_type(var, sh->Stage);
623 unsigned num_elements = type->count_attribute_slots(false);
624 unsigned idx = compute_variable_location_slot(var, sh->Stage);
625 unsigned slot_limit = idx + num_elements;
626
627 /* Vertex shader inputs and fragment shader outputs are validated in
628 * assign_attribute_or_color_locations() so we should not attempt to
629 * validate them again here.
630 */
631 unsigned slot_max;
632 if (var->data.mode == ir_var_shader_out) {
633 assert(sh->Stage != MESA_SHADER_FRAGMENT)(static_cast <bool> (sh->Stage != MESA_SHADER_FRAGMENT
) ? void (0) : __assert_fail ("sh->Stage != MESA_SHADER_FRAGMENT"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
634 slot_max =
635 ctx->Const.Program[sh->Stage].MaxOutputComponents / 4;
636 } else {
637 assert(var->data.mode == ir_var_shader_in)(static_cast <bool> (var->data.mode == ir_var_shader_in
) ? void (0) : __assert_fail ("var->data.mode == ir_var_shader_in"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
638 assert(sh->Stage != MESA_SHADER_VERTEX)(static_cast <bool> (sh->Stage != MESA_SHADER_VERTEX
) ? void (0) : __assert_fail ("sh->Stage != MESA_SHADER_VERTEX"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
639 slot_max =
640 ctx->Const.Program[sh->Stage].MaxInputComponents / 4;
641 }
642
643 if (slot_limit > slot_max) {
644 linker_error(prog,
645 "Invalid location %u in %s shader\n",
646 idx, _mesa_shader_stage_to_string(sh->Stage));
647 return false;
648 }
649
650 const glsl_type *type_without_array = type->without_array();
651 if (type_without_array->is_interface()) {
652 for (unsigned i = 0; i < type_without_array->length; i++) {
653 glsl_struct_field *field = &type_without_array->fields.structure[i];
654 unsigned field_location = field->location -
655 (field->patch ? VARYING_SLOT_PATCH0((VARYING_SLOT_VAR0 + 32)) : VARYING_SLOT_VAR0);
656 if (!check_location_aliasing(explicit_locations, var,
657 field_location,
658 0, field_location + 1,
659 field->type,
660 field->interpolation,
661 field->centroid,
662 field->sample,
663 field->patch,
664 prog, sh->Stage)) {
665 return false;
666 }
667 }
668 } else if (!check_location_aliasing(explicit_locations, var,
669 idx, var->data.location_frac,
670 slot_limit, type,
671 var->data.interpolation,
672 var->data.centroid,
673 var->data.sample,
674 var->data.patch,
675 prog, sh->Stage)) {
676 return false;
677 }
678
679 return true;
680}
681
682/**
683 * Validate explicit locations for the inputs to the first stage and the
684 * outputs of the last stage in a program, if those are not the VS and FS
685 * shaders.
686 */
687void
688validate_first_and_last_interface_explicit_locations(struct gl_context *ctx,
689 struct gl_shader_program *prog,
690 gl_shader_stage first_stage,
691 gl_shader_stage last_stage)
692{
693 /* VS inputs and FS outputs are validated in
694 * assign_attribute_or_color_locations()
695 */
696 bool validate_first_stage = first_stage != MESA_SHADER_VERTEX;
697 bool validate_last_stage = last_stage != MESA_SHADER_FRAGMENT;
698 if (!validate_first_stage && !validate_last_stage)
699 return;
700
701 struct explicit_location_info explicit_locations[MAX_VARYING32][4];
702
703 gl_shader_stage stages[2] = { first_stage, last_stage };
704 bool validate_stage[2] = { validate_first_stage, validate_last_stage };
705 ir_variable_mode var_direction[2] = { ir_var_shader_in, ir_var_shader_out };
706
707 for (unsigned i = 0; i < 2; i++) {
708 if (!validate_stage[i])
709 continue;
710
711 gl_shader_stage stage = stages[i];
712
713 gl_linked_shader *sh = prog->_LinkedShaders[stage];
714 assert(sh)(static_cast <bool> (sh) ? void (0) : __assert_fail ("sh"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
715
716 memset(explicit_locations, 0, sizeof(explicit_locations));
717
718 foreach_in_list(ir_instruction, node, sh->ir)for (ir_instruction *node = (!exec_node_is_tail_sentinel((sh->
ir)->head_sentinel.next) ? (ir_instruction *) ((sh->ir)
->head_sentinel.next) : __null); (node) != __null; (node) =
(!exec_node_is_tail_sentinel((node)->next) ? (ir_instruction
*) ((node)->next) : __null)) {
719 ir_variable *const var = node->as_variable();
720
721 if (var == NULL__null ||
722 !var->data.explicit_location ||
723 var->data.location < VARYING_SLOT_VAR0 ||
724 var->data.mode != var_direction[i])
725 continue;
726
727 if (!validate_explicit_variable_location(
728 ctx, explicit_locations, var, prog, sh)) {
729 return;
730 }
731 }
732 }
733}
734
735/**
736 * Validate that outputs from one stage match inputs of another
737 */
738void
739cross_validate_outputs_to_inputs(struct gl_context *ctx,
740 struct gl_shader_program *prog,
741 gl_linked_shader *producer,
742 gl_linked_shader *consumer)
743{
744 glsl_symbol_table parameters;
745 struct explicit_location_info output_explicit_locations[MAX_VARYING32][4] = {};
746 struct explicit_location_info input_explicit_locations[MAX_VARYING32][4] = {};
747
748 /* Find all shader outputs in the "producer" stage.
749 */
750 foreach_in_list(ir_instruction, node, producer->ir)for (ir_instruction *node = (!exec_node_is_tail_sentinel((producer
->ir)->head_sentinel.next) ? (ir_instruction *) ((producer
->ir)->head_sentinel.next) : __null); (node) != __null;
(node) = (!exec_node_is_tail_sentinel((node)->next) ? (ir_instruction
*) ((node)->next) : __null)) {
751 ir_variable *const var = node->as_variable();
752
753 if (var == NULL__null || var->data.mode != ir_var_shader_out)
754 continue;
755
756 if (!var->data.explicit_location
757 || var->data.location < VARYING_SLOT_VAR0)
758 parameters.add_variable(var);
759 else {
760 /* User-defined varyings with explicit locations are handled
761 * differently because they do not need to have matching names.
762 */
763 if (!validate_explicit_variable_location(ctx,
764 output_explicit_locations,
765 var, prog, producer)) {
766 return;
767 }
768 }
769 }
770
771
772 /* Find all shader inputs in the "consumer" stage. Any variables that have
773 * matching outputs already in the symbol table must have the same type and
774 * qualifiers.
775 *
776 * Exception: if the consumer is the geometry shader, then the inputs
777 * should be arrays and the type of the array element should match the type
778 * of the corresponding producer output.
779 */
780 foreach_in_list(ir_instruction, node, consumer->ir)for (ir_instruction *node = (!exec_node_is_tail_sentinel((consumer
->ir)->head_sentinel.next) ? (ir_instruction *) ((consumer
->ir)->head_sentinel.next) : __null); (node) != __null;
(node) = (!exec_node_is_tail_sentinel((node)->next) ? (ir_instruction
*) ((node)->next) : __null)) {
781 ir_variable *const input = node->as_variable();
782
783 if (input == NULL__null || input->data.mode != ir_var_shader_in)
784 continue;
785
786 if (strcmp(input->name, "gl_Color") == 0 && input->data.used) {
787 const ir_variable *const front_color =
788 parameters.get_variable("gl_FrontColor");
789
790 const ir_variable *const back_color =
791 parameters.get_variable("gl_BackColor");
792
793 cross_validate_front_and_back_color(ctx, prog, input,
794 front_color, back_color,
795 consumer->Stage, producer->Stage);
796 } else if (strcmp(input->name, "gl_SecondaryColor") == 0 && input->data.used) {
797 const ir_variable *const front_color =
798 parameters.get_variable("gl_FrontSecondaryColor");
799
800 const ir_variable *const back_color =
801 parameters.get_variable("gl_BackSecondaryColor");
802
803 cross_validate_front_and_back_color(ctx, prog, input,
804 front_color, back_color,
805 consumer->Stage, producer->Stage);
806 } else {
807 /* The rules for connecting inputs and outputs change in the presence
808 * of explicit locations. In this case, we no longer care about the
809 * names of the variables. Instead, we care only about the
810 * explicitly assigned location.
811 */
812 ir_variable *output = NULL__null;
813 if (input->data.explicit_location
814 && input->data.location >= VARYING_SLOT_VAR0) {
815
816 const glsl_type *type = get_varying_type(input, consumer->Stage);
817 unsigned num_elements = type->count_attribute_slots(false);
818 unsigned idx =
819 compute_variable_location_slot(input, consumer->Stage);
820 unsigned slot_limit = idx + num_elements;
821
822 if (!validate_explicit_variable_location(ctx,
823 input_explicit_locations,
824 input, prog, consumer)) {
825 return;
826 }
827
828 while (idx < slot_limit) {
829 if (idx >= MAX_VARYING32) {
830 linker_error(prog,
831 "Invalid location %u in %s shader\n", idx,
832 _mesa_shader_stage_to_string(consumer->Stage));
833 return;
834 }
835
836 output = output_explicit_locations[idx][input->data.location_frac].var;
837
838 if (output == NULL__null) {
839 /* A linker failure should only happen when there is no
840 * output declaration and there is Static Use of the
841 * declared input.
842 */
843 if (input->data.used) {
844 linker_error(prog,
845 "%s shader input `%s' with explicit location "
846 "has no matching output\n",
847 _mesa_shader_stage_to_string(consumer->Stage),
848 input->name);
849 break;
850 }
851 } else if (input->data.location != output->data.location) {
852 linker_error(prog,
853 "%s shader input `%s' with explicit location "
854 "has no matching output\n",
855 _mesa_shader_stage_to_string(consumer->Stage),
856 input->name);
857 break;
858 }
859 idx++;
860 }
861 } else {
862 output = parameters.get_variable(input->name);
863 }
864
865 if (output != NULL__null) {
866 /* Interface blocks have their own validation elsewhere so don't
867 * try validating them here.
868 */
869 if (!(input->get_interface_type() &&
870 output->get_interface_type()))
871 cross_validate_types_and_qualifiers(ctx, prog, input, output,
872 consumer->Stage,
873 producer->Stage);
874 } else {
875 /* Check for input vars with unmatched output vars in prev stage
876 * taking into account that interface blocks could have a matching
877 * output but with different name, so we ignore them.
878 */
879 assert(!input->data.assigned)(static_cast <bool> (!input->data.assigned) ? void (
0) : __assert_fail ("!input->data.assigned", __builtin_FILE
(), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__));
880 if (input->data.used && !input->get_interface_type() &&
881 !input->data.explicit_location)
882 linker_error(prog,
883 "%s shader input `%s' "
884 "has no matching output in the previous stage\n",
885 _mesa_shader_stage_to_string(consumer->Stage),
886 input->name);
887 }
888 }
889 }
890}
891
892/**
893 * Demote shader inputs and outputs that are not used in other stages, and
894 * remove them via dead code elimination.
895 */
896static void
897remove_unused_shader_inputs_and_outputs(bool is_separate_shader_object,
898 gl_linked_shader *sh,
899 enum ir_variable_mode mode)
900{
901 if (is_separate_shader_object)
902 return;
903
904 foreach_in_list(ir_instruction, node, sh->ir)for (ir_instruction *node = (!exec_node_is_tail_sentinel((sh->
ir)->head_sentinel.next) ? (ir_instruction *) ((sh->ir)
->head_sentinel.next) : __null); (node) != __null; (node) =
(!exec_node_is_tail_sentinel((node)->next) ? (ir_instruction
*) ((node)->next) : __null)) {
905 ir_variable *const var = node->as_variable();
906
907 if (var == NULL__null || var->data.mode != int(mode))
908 continue;
909
910 /* A shader 'in' or 'out' variable is only really an input or output if
911 * its value is used by other shader stages. This will cause the
912 * variable to have a location assigned.
913 */
914 if (var->data.is_unmatched_generic_inout && !var->data.is_xfb_only) {
915 assert(var->data.mode != ir_var_temporary)(static_cast <bool> (var->data.mode != ir_var_temporary
) ? void (0) : __assert_fail ("var->data.mode != ir_var_temporary"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
916
917 /* Assign zeros to demoted inputs to allow more optimizations. */
918 if (var->data.mode == ir_var_shader_in && !var->constant_value)
919 var->constant_value = ir_constant::zero(var, var->type);
920
921 var->data.mode = ir_var_auto;
922 }
923 }
924
925 /* Eliminate code that is now dead due to unused inputs/outputs being
926 * demoted.
927 */
928 while (do_dead_code(sh->ir, false))
929 ;
930
931}
932
933/**
934 * Initialize this object based on a string that was passed to
935 * glTransformFeedbackVaryings.
936 *
937 * If the input is mal-formed, this call still succeeds, but it sets
938 * this->var_name to a mal-formed input, so tfeedback_decl::find_output_var()
939 * will fail to find any matching variable.
940 */
941void
942tfeedback_decl::init(struct gl_context *ctx, const void *mem_ctx,
943 const char *input)
944{
945 /* We don't have to be pedantic about what is a valid GLSL variable name,
946 * because any variable with an invalid name can't exist in the IR anyway.
947 */
948
949 this->location = -1;
950 this->orig_name = input;
951 this->lowered_builtin_array_variable = none;
952 this->skip_components = 0;
953 this->next_buffer_separator = false;
954 this->matched_candidate = NULL__null;
955 this->stream_id = 0;
956 this->buffer = 0;
957 this->offset = 0;
958
959 if (ctx->Extensions.ARB_transform_feedback3) {
960 /* Parse gl_NextBuffer. */
961 if (strcmp(input, "gl_NextBuffer") == 0) {
962 this->next_buffer_separator = true;
963 return;
964 }
965
966 /* Parse gl_SkipComponents. */
967 if (strcmp(input, "gl_SkipComponents1") == 0)
968 this->skip_components = 1;
969 else if (strcmp(input, "gl_SkipComponents2") == 0)
970 this->skip_components = 2;
971 else if (strcmp(input, "gl_SkipComponents3") == 0)
972 this->skip_components = 3;
973 else if (strcmp(input, "gl_SkipComponents4") == 0)
974 this->skip_components = 4;
975
976 if (this->skip_components)
977 return;
978 }
979
980 /* Parse a declaration. */
981 const char *base_name_end;
982 long subscript = parse_program_resource_name(input, &base_name_end);
983 this->var_name = ralloc_strndup(mem_ctx, input, base_name_end - input);
984 if (this->var_name == NULL__null) {
985 _mesa_error_no_memory(__func____func__);
986 return;
987 }
988
989 if (subscript >= 0) {
990 this->array_subscript = subscript;
991 this->is_subscripted = true;
992 } else {
993 this->is_subscripted = false;
994 }
995
996 /* For drivers that lower gl_ClipDistance to gl_ClipDistanceMESA, this
997 * class must behave specially to account for the fact that gl_ClipDistance
998 * is converted from a float[8] to a vec4[2].
999 */
1000 if (ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerCombinedClipCullDistance &&
1001 strcmp(this->var_name, "gl_ClipDistance") == 0) {
1002 this->lowered_builtin_array_variable = clip_distance;
1003 }
1004 if (ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].LowerCombinedClipCullDistance &&
1005 strcmp(this->var_name, "gl_CullDistance") == 0) {
1006 this->lowered_builtin_array_variable = cull_distance;
1007 }
1008
1009 if (ctx->Const.LowerTessLevel &&
1010 (strcmp(this->var_name, "gl_TessLevelOuter") == 0))
1011 this->lowered_builtin_array_variable = tess_level_outer;
1012 if (ctx->Const.LowerTessLevel &&
1013 (strcmp(this->var_name, "gl_TessLevelInner") == 0))
1014 this->lowered_builtin_array_variable = tess_level_inner;
1015}
1016
1017
1018/**
1019 * Determine whether two tfeedback_decl objects refer to the same variable and
1020 * array index (if applicable).
1021 */
1022bool
1023tfeedback_decl::is_same(const tfeedback_decl &x, const tfeedback_decl &y)
1024{
1025 assert(x.is_varying() && y.is_varying())(static_cast <bool> (x.is_varying() && y.is_varying
()) ? void (0) : __assert_fail ("x.is_varying() && y.is_varying()"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
1026
1027 if (strcmp(x.var_name, y.var_name) != 0)
1028 return false;
1029 if (x.is_subscripted != y.is_subscripted)
1030 return false;
1031 if (x.is_subscripted && x.array_subscript != y.array_subscript)
1032 return false;
1033 return true;
1034}
1035
1036
1037/**
1038 * Assign a location and stream ID for this tfeedback_decl object based on the
1039 * transform feedback candidate found by find_candidate.
1040 *
1041 * If an error occurs, the error is reported through linker_error() and false
1042 * is returned.
1043 */
1044bool
1045tfeedback_decl::assign_location(struct gl_context *ctx,
1046 struct gl_shader_program *prog)
1047{
1048 assert(this->is_varying())(static_cast <bool> (this->is_varying()) ? void (0) :
__assert_fail ("this->is_varying()", __builtin_FILE (), __builtin_LINE
(), __extension__ __PRETTY_FUNCTION__));
1049
1050 unsigned fine_location
1051 = this->matched_candidate->toplevel_var->data.location * 4
1052 + this->matched_candidate->toplevel_var->data.location_frac
1053 + this->matched_candidate->offset;
1054 const unsigned dmul =
1055 this->matched_candidate->type->without_array()->is_64bit() ? 2 : 1;
1056
1057 if (this->matched_candidate->type->is_array()) {
1058 /* Array variable */
1059 const unsigned matrix_cols =
1060 this->matched_candidate->type->fields.array->matrix_columns;
1061 const unsigned vector_elements =
1062 this->matched_candidate->type->fields.array->vector_elements;
1063 unsigned actual_array_size;
1064 switch (this->lowered_builtin_array_variable) {
1065 case clip_distance:
1066 actual_array_size = prog->last_vert_prog ?
1067 prog->last_vert_prog->info.clip_distance_array_size : 0;
1068 break;
1069 case cull_distance:
1070 actual_array_size = prog->last_vert_prog ?
1071 prog->last_vert_prog->info.cull_distance_array_size : 0;
1072 break;
1073 case tess_level_outer:
1074 actual_array_size = 4;
1075 break;
1076 case tess_level_inner:
1077 actual_array_size = 2;
1078 break;
1079 case none:
1080 default:
1081 actual_array_size = this->matched_candidate->type->array_size();
1082 break;
1083 }
1084
1085 if (this->is_subscripted) {
1086 /* Check array bounds. */
1087 if (this->array_subscript >= actual_array_size) {
1088 linker_error(prog, "Transform feedback varying %s has index "
1089 "%i, but the array size is %u.",
1090 this->orig_name, this->array_subscript,
1091 actual_array_size);
1092 return false;
1093 }
1094 unsigned array_elem_size = this->lowered_builtin_array_variable ?
1095 1 : vector_elements * matrix_cols * dmul;
1096 fine_location += array_elem_size * this->array_subscript;
1097 this->size = 1;
1098 } else {
1099 this->size = actual_array_size;
1100 }
1101 this->vector_elements = vector_elements;
1102 this->matrix_columns = matrix_cols;
1103 if (this->lowered_builtin_array_variable)
1104 this->type = GL_FLOAT0x1406;
1105 else
1106 this->type = this->matched_candidate->type->fields.array->gl_type;
1107 } else {
1108 /* Regular variable (scalar, vector, or matrix) */
1109 if (this->is_subscripted) {
1110 linker_error(prog, "Transform feedback varying %s requested, "
1111 "but %s is not an array.",
1112 this->orig_name, this->var_name);
1113 return false;
1114 }
1115 this->size = 1;
1116 this->vector_elements = this->matched_candidate->type->vector_elements;
1117 this->matrix_columns = this->matched_candidate->type->matrix_columns;
1118 this->type = this->matched_candidate->type->gl_type;
1119 }
1120 this->location = fine_location / 4;
1121 this->location_frac = fine_location % 4;
1122
1123 /* From GL_EXT_transform_feedback:
1124 * A program will fail to link if:
1125 *
1126 * * the total number of components to capture in any varying
1127 * variable in <varyings> is greater than the constant
1128 * MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS_EXT and the
1129 * buffer mode is SEPARATE_ATTRIBS_EXT;
1130 */
1131 if (prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS0x8C8D &&
1132 this->num_components() >
1133 ctx->Const.MaxTransformFeedbackSeparateComponents) {
1134 linker_error(prog, "Transform feedback varying %s exceeds "
1135 "MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS.",
1136 this->orig_name);
1137 return false;
1138 }
1139
1140 /* Only transform feedback varyings can be assigned to non-zero streams,
1141 * so assign the stream id here.
1142 */
1143 this->stream_id = this->matched_candidate->toplevel_var->data.stream;
1144
1145 unsigned array_offset = this->array_subscript * 4 * dmul;
1146 unsigned struct_offset = this->matched_candidate->offset * 4 * dmul;
1147 this->buffer = this->matched_candidate->toplevel_var->data.xfb_buffer;
1148 this->offset = this->matched_candidate->toplevel_var->data.offset +
1149 array_offset + struct_offset;
1150
1151 return true;
1152}
1153
1154
1155unsigned
1156tfeedback_decl::get_num_outputs() const
1157{
1158 if (!this->is_varying()) {
1159 return 0;
1160 }
1161 return (this->num_components() + this->location_frac + 3)/4;
1162}
1163
1164
1165/**
1166 * Update gl_transform_feedback_info to reflect this tfeedback_decl.
1167 *
1168 * If an error occurs, the error is reported through linker_error() and false
1169 * is returned.
1170 */
1171bool
1172tfeedback_decl::store(struct gl_context *ctx, struct gl_shader_program *prog,
1173 struct gl_transform_feedback_info *info,
1174 unsigned buffer, unsigned buffer_index,
1175 const unsigned max_outputs,
1176 BITSET_WORDunsigned int *used_components[MAX_FEEDBACK_BUFFERS4],
1177 bool *explicit_stride, bool has_xfb_qualifiers,
1178 const void* mem_ctx) const
1179{
1180 unsigned xfb_offset = 0;
1181 unsigned size = this->size;
1182 /* Handle gl_SkipComponents. */
1183 if (this->skip_components) {
1184 info->Buffers[buffer].Stride += this->skip_components;
1185 size = this->skip_components;
1186 goto store_varying;
1187 }
1188
1189 if (this->next_buffer_separator) {
1190 size = 0;
1191 goto store_varying;
1192 }
1193
1194 if (has_xfb_qualifiers) {
1195 xfb_offset = this->offset / 4;
1196 } else {
1197 xfb_offset = info->Buffers[buffer].Stride;
1198 }
1199 info->Varyings[info->NumVarying].Offset = xfb_offset * 4;
1200
1201 {
1202 unsigned location = this->location;
1203 unsigned location_frac = this->location_frac;
1204 unsigned num_components = this->num_components();
1205
1206 /* From GL_EXT_transform_feedback:
1207 *
1208 * " A program will fail to link if:
1209 *
1210 * * the total number of components to capture is greater than the
1211 * constant MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS_EXT
1212 * and the buffer mode is INTERLEAVED_ATTRIBS_EXT."
1213 *
1214 * From GL_ARB_enhanced_layouts:
1215 *
1216 * " The resulting stride (implicit or explicit) must be less than or
1217 * equal to the implementation-dependent constant
1218 * gl_MaxTransformFeedbackInterleavedComponents."
1219 */
1220 if ((prog->TransformFeedback.BufferMode == GL_INTERLEAVED_ATTRIBS0x8C8C ||
1221 has_xfb_qualifiers) &&
1222 xfb_offset + num_components >
1223 ctx->Const.MaxTransformFeedbackInterleavedComponents) {
1224 linker_error(prog,
1225 "The MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS "
1226 "limit has been exceeded.");
1227 return false;
1228 }
1229
1230 /* From the OpenGL 4.60.5 spec, section 4.4.2. Output Layout Qualifiers,
1231 * Page 76, (Transform Feedback Layout Qualifiers):
1232 *
1233 * " No aliasing in output buffers is allowed: It is a compile-time or
1234 * link-time error to specify variables with overlapping transform
1235 * feedback offsets."
1236 */
1237 const unsigned max_components =
1238 ctx->Const.MaxTransformFeedbackInterleavedComponents;
1239 const unsigned first_component = xfb_offset;
1240 const unsigned last_component = xfb_offset + num_components - 1;
1241 const unsigned start_word = BITSET_BITWORD(first_component)((first_component) / (sizeof (unsigned int) * 8));
1242 const unsigned end_word = BITSET_BITWORD(last_component)((last_component) / (sizeof (unsigned int) * 8));
1243 BITSET_WORDunsigned int *used;
1244 assert(last_component < max_components)(static_cast <bool> (last_component < max_components
) ? void (0) : __assert_fail ("last_component < max_components"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
1245
1246 if (!used_components[buffer]) {
1247 used_components[buffer] =
1248 rzalloc_array(mem_ctx, BITSET_WORD, BITSET_WORDS(max_components))((unsigned int *) rzalloc_array_size(mem_ctx, sizeof(unsigned
int), (((max_components) + (sizeof (unsigned int) * 8) - 1) /
(sizeof (unsigned int) * 8))));
1249 }
1250 used = used_components[buffer];
1251
1252 for (unsigned word = start_word; word <= end_word; word++) {
1253 unsigned start_range = 0;
1254 unsigned end_range = BITSET_WORDBITS(sizeof (unsigned int) * 8) - 1;
1255
1256 if (word == start_word)
1257 start_range = first_component % BITSET_WORDBITS(sizeof (unsigned int) * 8);
1258
1259 if (word == end_word)
1260 end_range = last_component % BITSET_WORDBITS(sizeof (unsigned int) * 8);
1261
1262 if (used[word] & BITSET_RANGE(start_range, end_range)((((((end_range) + 1) % (sizeof (unsigned int) * 8) == 0) ? ~
0 : (1u << (((end_range) + 1) % (sizeof (unsigned int) *
8))) - 1)) & ~((1u << ((start_range) % (sizeof (unsigned
int) * 8))) - 1))) {
1263 linker_error(prog,
1264 "variable '%s', xfb_offset (%d) is causing aliasing.",
1265 this->orig_name, xfb_offset * 4);
1266 return false;
1267 }
1268 used[word] |= BITSET_RANGE(start_range, end_range)((((((end_range) + 1) % (sizeof (unsigned int) * 8) == 0) ? ~
0 : (1u << (((end_range) + 1) % (sizeof (unsigned int) *
8))) - 1)) & ~((1u << ((start_range) % (sizeof (unsigned
int) * 8))) - 1));
1269 }
1270
1271 while (num_components > 0) {
1272 unsigned output_size = MIN2(num_components, 4 - location_frac)( (num_components)<(4 - location_frac) ? (num_components) :
(4 - location_frac) );
1273 assert((info->NumOutputs == 0 && max_outputs == 0) ||(static_cast <bool> ((info->NumOutputs == 0 &&
max_outputs == 0) || info->NumOutputs < max_outputs) ?
void (0) : __assert_fail ("(info->NumOutputs == 0 && max_outputs == 0) || info->NumOutputs < max_outputs"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
))
1274 info->NumOutputs < max_outputs)(static_cast <bool> ((info->NumOutputs == 0 &&
max_outputs == 0) || info->NumOutputs < max_outputs) ?
void (0) : __assert_fail ("(info->NumOutputs == 0 && max_outputs == 0) || info->NumOutputs < max_outputs"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
1275
1276 /* From the ARB_enhanced_layouts spec:
1277 *
1278 * "If such a block member or variable is not written during a shader
1279 * invocation, the buffer contents at the assigned offset will be
1280 * undefined. Even if there are no static writes to a variable or
1281 * member that is assigned a transform feedback offset, the space is
1282 * still allocated in the buffer and still affects the stride."
1283 */
1284 if (this->is_varying_written()) {
1285 info->Outputs[info->NumOutputs].ComponentOffset = location_frac;
1286 info->Outputs[info->NumOutputs].OutputRegister = location;
1287 info->Outputs[info->NumOutputs].NumComponents = output_size;
1288 info->Outputs[info->NumOutputs].StreamId = stream_id;
1289 info->Outputs[info->NumOutputs].OutputBuffer = buffer;
1290 info->Outputs[info->NumOutputs].DstOffset = xfb_offset;
1291 ++info->NumOutputs;
1292 }
1293 info->Buffers[buffer].Stream = this->stream_id;
1294 xfb_offset += output_size;
1295
1296 num_components -= output_size;
1297 location++;
1298 location_frac = 0;
1299 }
1300 }
1301
1302 if (explicit_stride && explicit_stride[buffer]) {
1303 if (this->is_64bit() && info->Buffers[buffer].Stride % 2) {
1304 linker_error(prog, "invalid qualifier xfb_stride=%d must be a "
1305 "multiple of 8 as its applied to a type that is or "
1306 "contains a double.",
1307 info->Buffers[buffer].Stride * 4);
1308 return false;
1309 }
1310
1311 if (xfb_offset > info->Buffers[buffer].Stride) {
1312 linker_error(prog, "xfb_offset (%d) overflows xfb_stride (%d) for "
1313 "buffer (%d)", xfb_offset * 4,
1314 info->Buffers[buffer].Stride * 4, buffer);
1315 return false;
1316 }
1317 } else {
1318 info->Buffers[buffer].Stride = xfb_offset;
1319 }
1320
1321 store_varying:
1322 info->Varyings[info->NumVarying].Name = ralloc_strdup(prog,
1323 this->orig_name);
1324 info->Varyings[info->NumVarying].Type = this->type;
1325 info->Varyings[info->NumVarying].Size = size;
1326 info->Varyings[info->NumVarying].BufferIndex = buffer_index;
1327 info->NumVarying++;
1328 info->Buffers[buffer].NumVaryings++;
1329
1330 return true;
1331}
1332
1333
1334const tfeedback_candidate *
1335tfeedback_decl::find_candidate(gl_shader_program *prog,
1336 hash_table *tfeedback_candidates)
1337{
1338 const char *name = this->var_name;
1339 switch (this->lowered_builtin_array_variable) {
1340 case none:
1341 name = this->var_name;
1342 break;
1343 case clip_distance:
1344 name = "gl_ClipDistanceMESA";
1345 break;
1346 case cull_distance:
1347 name = "gl_CullDistanceMESA";
1348 break;
1349 case tess_level_outer:
1350 name = "gl_TessLevelOuterMESA";
1351 break;
1352 case tess_level_inner:
1353 name = "gl_TessLevelInnerMESA";
1354 break;
1355 }
1356 hash_entry *entry = _mesa_hash_table_search(tfeedback_candidates, name);
1357
1358 this->matched_candidate = entry ?
1359 (const tfeedback_candidate *) entry->data : NULL__null;
1360
1361 if (!this->matched_candidate) {
1362 /* From GL_EXT_transform_feedback:
1363 * A program will fail to link if:
1364 *
1365 * * any variable name specified in the <varyings> array is not
1366 * declared as an output in the geometry shader (if present) or
1367 * the vertex shader (if no geometry shader is present);
1368 */
1369 linker_error(prog, "Transform feedback varying %s undeclared.",
1370 this->orig_name);
1371 }
1372
1373 return this->matched_candidate;
1374}
1375
1376/**
1377 * Force a candidate over the previously matched one. It happens when a new
1378 * varying needs to be created to match the xfb declaration, for example,
1379 * to fullfil an alignment criteria.
1380 */
1381void
1382tfeedback_decl::set_lowered_candidate(const tfeedback_candidate *candidate)
1383{
1384 this->matched_candidate = candidate;
1385
1386 /* The subscript part is no longer relevant */
1387 this->is_subscripted = false;
1388 this->array_subscript = 0;
1389}
1390
1391
1392/**
1393 * Parse all the transform feedback declarations that were passed to
1394 * glTransformFeedbackVaryings() and store them in tfeedback_decl objects.
1395 *
1396 * If an error occurs, the error is reported through linker_error() and false
1397 * is returned.
1398 */
1399static bool
1400parse_tfeedback_decls(struct gl_context *ctx, struct gl_shader_program *prog,
1401 const void *mem_ctx, unsigned num_names,
1402 char **varying_names, tfeedback_decl *decls)
1403{
1404 for (unsigned i = 0; i < num_names; ++i) {
1405 decls[i].init(ctx, mem_ctx, varying_names[i]);
1406
1407 if (!decls[i].is_varying())
1408 continue;
1409
1410 /* From GL_EXT_transform_feedback:
1411 * A program will fail to link if:
1412 *
1413 * * any two entries in the <varyings> array specify the same varying
1414 * variable;
1415 *
1416 * We interpret this to mean "any two entries in the <varyings> array
1417 * specify the same varying variable and array index", since transform
1418 * feedback of arrays would be useless otherwise.
1419 */
1420 for (unsigned j = 0; j < i; ++j) {
1421 if (decls[j].is_varying()) {
1422 if (tfeedback_decl::is_same(decls[i], decls[j])) {
1423 linker_error(prog, "Transform feedback varying %s specified "
1424 "more than once.", varying_names[i]);
1425 return false;
1426 }
1427 }
1428 }
1429 }
1430 return true;
1431}
1432
1433
1434static int
1435cmp_xfb_offset(const void * x_generic, const void * y_generic)
1436{
1437 tfeedback_decl *x = (tfeedback_decl *) x_generic;
1438 tfeedback_decl *y = (tfeedback_decl *) y_generic;
1439
1440 if (x->get_buffer() != y->get_buffer())
1441 return x->get_buffer() - y->get_buffer();
1442 return x->get_offset() - y->get_offset();
1443}
1444
1445/**
1446 * Store transform feedback location assignments into
1447 * prog->sh.LinkedTransformFeedback based on the data stored in
1448 * tfeedback_decls.
1449 *
1450 * If an error occurs, the error is reported through linker_error() and false
1451 * is returned.
1452 */
1453static bool
1454store_tfeedback_info(struct gl_context *ctx, struct gl_shader_program *prog,
1455 unsigned num_tfeedback_decls,
1456 tfeedback_decl *tfeedback_decls, bool has_xfb_qualifiers,
1457 const void *mem_ctx)
1458{
1459 if (!prog->last_vert_prog)
1460 return true;
1461
1462 /* Make sure MaxTransformFeedbackBuffers is less than 32 so the bitmask for
1463 * tracking the number of buffers doesn't overflow.
1464 */
1465 assert(ctx->Const.MaxTransformFeedbackBuffers < 32)(static_cast <bool> (ctx->Const.MaxTransformFeedbackBuffers
< 32) ? void (0) : __assert_fail ("ctx->Const.MaxTransformFeedbackBuffers < 32"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
1466
1467 bool separate_attribs_mode =
1468 prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS0x8C8D;
1469
1470 struct gl_program *xfb_prog = prog->last_vert_prog;
1471 xfb_prog->sh.LinkedTransformFeedback =
1472 rzalloc(xfb_prog, struct gl_transform_feedback_info)((struct gl_transform_feedback_info *) rzalloc_size(xfb_prog,
sizeof(struct gl_transform_feedback_info)));
1473
1474 /* The xfb_offset qualifier does not have to be used in increasing order
1475 * however some drivers expect to receive the list of transform feedback
1476 * declarations in order so sort it now for convenience.
1477 */
1478 if (has_xfb_qualifiers) {
1479 qsort(tfeedback_decls, num_tfeedback_decls, sizeof(*tfeedback_decls),
1480 cmp_xfb_offset);
1481 }
1482
1483 xfb_prog->sh.LinkedTransformFeedback->Varyings =
1484 rzalloc_array(xfb_prog, struct gl_transform_feedback_varying_info,((struct gl_transform_feedback_varying_info *) rzalloc_array_size
(xfb_prog, sizeof(struct gl_transform_feedback_varying_info),
num_tfeedback_decls))
1485 num_tfeedback_decls)((struct gl_transform_feedback_varying_info *) rzalloc_array_size
(xfb_prog, sizeof(struct gl_transform_feedback_varying_info),
num_tfeedback_decls));
1486
1487 unsigned num_outputs = 0;
1488 for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
1489 if (tfeedback_decls[i].is_varying_written())
1490 num_outputs += tfeedback_decls[i].get_num_outputs();
1491 }
1492
1493 xfb_prog->sh.LinkedTransformFeedback->Outputs =
1494 rzalloc_array(xfb_prog, struct gl_transform_feedback_output,((struct gl_transform_feedback_output *) rzalloc_array_size(xfb_prog
, sizeof(struct gl_transform_feedback_output), num_outputs))
1495 num_outputs)((struct gl_transform_feedback_output *) rzalloc_array_size(xfb_prog
, sizeof(struct gl_transform_feedback_output), num_outputs));
1496
1497 unsigned num_buffers = 0;
1498 unsigned buffers = 0;
1499 BITSET_WORDunsigned int *used_components[MAX_FEEDBACK_BUFFERS4] = {};
1500
1501 if (!has_xfb_qualifiers && separate_attribs_mode) {
1502 /* GL_SEPARATE_ATTRIBS */
1503 for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
1504 if (!tfeedback_decls[i].store(ctx, prog,
1505 xfb_prog->sh.LinkedTransformFeedback,
1506 num_buffers, num_buffers, num_outputs,
1507 used_components, NULL__null,
1508 has_xfb_qualifiers, mem_ctx))
1509 return false;
1510
1511 buffers |= 1 << num_buffers;
1512 num_buffers++;
1513 }
1514 }
1515 else {
1516 /* GL_INVERLEAVED_ATTRIBS */
1517 int buffer_stream_id = -1;
1518 unsigned buffer =
1519 num_tfeedback_decls ? tfeedback_decls[0].get_buffer() : 0;
1520 bool explicit_stride[MAX_FEEDBACK_BUFFERS4] = { false };
1521
1522 /* Apply any xfb_stride global qualifiers */
1523 if (has_xfb_qualifiers) {
1524 for (unsigned j = 0; j < MAX_FEEDBACK_BUFFERS4; j++) {
1525 if (prog->TransformFeedback.BufferStride[j]) {
1526 explicit_stride[j] = true;
1527 xfb_prog->sh.LinkedTransformFeedback->Buffers[j].Stride =
1528 prog->TransformFeedback.BufferStride[j] / 4;
1529 }
1530 }
1531 }
1532
1533 for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
1534 if (has_xfb_qualifiers &&
1535 buffer != tfeedback_decls[i].get_buffer()) {
1536 /* we have moved to the next buffer so reset stream id */
1537 buffer_stream_id = -1;
1538 num_buffers++;
1539 }
1540
1541 if (tfeedback_decls[i].is_next_buffer_separator()) {
1542 if (!tfeedback_decls[i].store(ctx, prog,
1543 xfb_prog->sh.LinkedTransformFeedback,
1544 buffer, num_buffers, num_outputs,
1545 used_components, explicit_stride,
1546 has_xfb_qualifiers, mem_ctx))
1547 return false;
1548 num_buffers++;
1549 buffer_stream_id = -1;
1550 continue;
1551 }
1552
1553 if (has_xfb_qualifiers) {
1554 buffer = tfeedback_decls[i].get_buffer();
1555 } else {
1556 buffer = num_buffers;
1557 }
1558
1559 if (tfeedback_decls[i].is_varying()) {
1560 if (buffer_stream_id == -1) {
1561 /* First varying writing to this buffer: remember its stream */
1562 buffer_stream_id = (int) tfeedback_decls[i].get_stream_id();
1563
1564 /* Only mark a buffer as active when there is a varying
1565 * attached to it. This behaviour is based on a revised version
1566 * of section 13.2.2 of the GL 4.6 spec.
1567 */
1568 buffers |= 1 << buffer;
1569 } else if (buffer_stream_id !=
1570 (int) tfeedback_decls[i].get_stream_id()) {
1571 /* Varying writes to the same buffer from a different stream */
1572 linker_error(prog,
1573 "Transform feedback can't capture varyings belonging "
1574 "to different vertex streams in a single buffer. "
1575 "Varying %s writes to buffer from stream %u, other "
1576 "varyings in the same buffer write from stream %u.",
1577 tfeedback_decls[i].name(),
1578 tfeedback_decls[i].get_stream_id(),
1579 buffer_stream_id);
1580 return false;
1581 }
1582 }
1583
1584 if (!tfeedback_decls[i].store(ctx, prog,
1585 xfb_prog->sh.LinkedTransformFeedback,
1586 buffer, num_buffers, num_outputs,
1587 used_components, explicit_stride,
1588 has_xfb_qualifiers, mem_ctx))
1589 return false;
1590 }
1591 }
1592
1593 assert(xfb_prog->sh.LinkedTransformFeedback->NumOutputs == num_outputs)(static_cast <bool> (xfb_prog->sh.LinkedTransformFeedback
->NumOutputs == num_outputs) ? void (0) : __assert_fail ("xfb_prog->sh.LinkedTransformFeedback->NumOutputs == num_outputs"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
1594
1595 xfb_prog->sh.LinkedTransformFeedback->ActiveBuffers = buffers;
1596 return true;
1597}
1598
1599namespace {
1600
1601/**
1602 * Data structure recording the relationship between outputs of one shader
1603 * stage (the "producer") and inputs of another (the "consumer").
1604 */
1605class varying_matches
1606{
1607public:
1608 varying_matches(bool disable_varying_packing,
1609 bool disable_xfb_packing,
1610 bool xfb_enabled,
1611 bool enhanced_layouts_enabled,
1612 gl_shader_stage producer_stage,
1613 gl_shader_stage consumer_stage);
1614 ~varying_matches();
1615 void record(ir_variable *producer_var, ir_variable *consumer_var);
1616 unsigned assign_locations(struct gl_shader_program *prog,
1617 uint8_t components[],
1618 uint64_t reserved_slots);
1619 void store_locations() const;
1620
1621private:
1622 bool is_varying_packing_safe(const glsl_type *type,
1623 const ir_variable *var) const;
1624
1625 /**
1626 * If true, this driver disables varying packing, so all varyings need to
1627 * be aligned on slot boundaries, and take up a number of slots equal to
1628 * their number of matrix columns times their array size.
1629 *
1630 * Packing may also be disabled because our current packing method is not
1631 * safe in SSO or versions of OpenGL where interpolation qualifiers are not
1632 * guaranteed to match across stages.
1633 */
1634 const bool disable_varying_packing;
1635
1636 /**
1637 * If true, this driver disables packing for varyings used by transform
1638 * feedback.
1639 */
1640 const bool disable_xfb_packing;
1641
1642 /**
1643 * If true, this driver has transform feedback enabled. The transform
1644 * feedback code usually requires at least some packing be done even
1645 * when varying packing is disabled, fortunately where transform feedback
1646 * requires packing it's safe to override the disabled setting. See
1647 * is_varying_packing_safe().
1648 */
1649 const bool xfb_enabled;
1650
1651 const bool enhanced_layouts_enabled;
1652
1653 /**
1654 * Enum representing the order in which varyings are packed within a
1655 * packing class.
1656 *
1657 * Currently we pack vec4's first, then vec2's, then scalar values, then
1658 * vec3's. This order ensures that the only vectors that are at risk of
1659 * having to be "double parked" (split between two adjacent varying slots)
1660 * are the vec3's.
1661 */
1662 enum packing_order_enum {
1663 PACKING_ORDER_VEC4,
1664 PACKING_ORDER_VEC2,
1665 PACKING_ORDER_SCALAR,
1666 PACKING_ORDER_VEC3,
1667 };
1668
1669 static unsigned compute_packing_class(const ir_variable *var);
1670 static packing_order_enum compute_packing_order(const ir_variable *var);
1671 static int match_comparator(const void *x_generic, const void *y_generic);
1672 static int xfb_comparator(const void *x_generic, const void *y_generic);
1673 static int not_xfb_comparator(const void *x_generic, const void *y_generic);
1674
1675 /**
1676 * Structure recording the relationship between a single producer output
1677 * and a single consumer input.
1678 */
1679 struct match {
1680 /**
1681 * Packing class for this varying, computed by compute_packing_class().
1682 */
1683 unsigned packing_class;
1684
1685 /**
1686 * Packing order for this varying, computed by compute_packing_order().
1687 */
1688 packing_order_enum packing_order;
1689 unsigned num_components;
1690
1691 /**
1692 * The output variable in the producer stage.
1693 */
1694 ir_variable *producer_var;
1695
1696 /**
1697 * The input variable in the consumer stage.
1698 */
1699 ir_variable *consumer_var;
1700
1701 /**
1702 * The location which has been assigned for this varying. This is
1703 * expressed in multiples of a float, with the first generic varying
1704 * (i.e. the one referred to by VARYING_SLOT_VAR0) represented by the
1705 * value 0.
1706 */
1707 unsigned generic_location;
1708 } *matches;
1709
1710 /**
1711 * The number of elements in the \c matches array that are currently in
1712 * use.
1713 */
1714 unsigned num_matches;
1715
1716 /**
1717 * The number of elements that were set aside for the \c matches array when
1718 * it was allocated.
1719 */
1720 unsigned matches_capacity;
1721
1722 gl_shader_stage producer_stage;
1723 gl_shader_stage consumer_stage;
1724};
1725
1726} /* anonymous namespace */
1727
1728varying_matches::varying_matches(bool disable_varying_packing,
1729 bool disable_xfb_packing,
1730 bool xfb_enabled,
1731 bool enhanced_layouts_enabled,
1732 gl_shader_stage producer_stage,
1733 gl_shader_stage consumer_stage)
1734 : disable_varying_packing(disable_varying_packing),
1735 disable_xfb_packing(disable_xfb_packing),
1736 xfb_enabled(xfb_enabled),
1737 enhanced_layouts_enabled(enhanced_layouts_enabled),
1738 producer_stage(producer_stage),
1739 consumer_stage(consumer_stage)
1740{
1741 /* Note: this initial capacity is rather arbitrarily chosen to be large
1742 * enough for many cases without wasting an unreasonable amount of space.
1743 * varying_matches::record() will resize the array if there are more than
1744 * this number of varyings.
1745 */
1746 this->matches_capacity = 8;
1747 this->matches = (match *)
1748 malloc(sizeof(*this->matches) * this->matches_capacity);
1749 this->num_matches = 0;
1750}
1751
1752
1753varying_matches::~varying_matches()
1754{
1755 free(this->matches);
1756}
1757
1758
1759/**
1760 * Packing is always safe on individual arrays, structures, and matrices. It
1761 * is also safe if the varying is only used for transform feedback.
1762 */
1763bool
1764varying_matches::is_varying_packing_safe(const glsl_type *type,
1765 const ir_variable *var) const
1766{
1767 if (consumer_stage == MESA_SHADER_TESS_EVAL ||
1768 consumer_stage == MESA_SHADER_TESS_CTRL ||
1769 producer_stage == MESA_SHADER_TESS_CTRL)
1770 return false;
1771
1772 return xfb_enabled && (type->is_array() || type->is_struct() ||
1773 type->is_matrix() || var->data.is_xfb_only);
1774}
1775
1776
1777/**
1778 * Record the given producer/consumer variable pair in the list of variables
1779 * that should later be assigned locations.
1780 *
1781 * It is permissible for \c consumer_var to be NULL (this happens if a
1782 * variable is output by the producer and consumed by transform feedback, but
1783 * not consumed by the consumer).
1784 *
1785 * If \c producer_var has already been paired up with a consumer_var, or
1786 * producer_var is part of fixed pipeline functionality (and hence already has
1787 * a location assigned), this function has no effect.
1788 *
1789 * Note: as a side effect this function may change the interpolation type of
1790 * \c producer_var, but only when the change couldn't possibly affect
1791 * rendering.
1792 */
1793void
1794varying_matches::record(ir_variable *producer_var, ir_variable *consumer_var)
1795{
1796 assert(producer_var != NULL || consumer_var != NULL)(static_cast <bool> (producer_var != __null || consumer_var
!= __null) ? void (0) : __assert_fail ("producer_var != NULL || consumer_var != NULL"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
1797
1798 if ((producer_var && (!producer_var->data.is_unmatched_generic_inout ||
1799 producer_var->data.explicit_location)) ||
1800 (consumer_var && (!consumer_var->data.is_unmatched_generic_inout ||
1801 consumer_var->data.explicit_location))) {
1802 /* Either a location already exists for this variable (since it is part
1803 * of fixed functionality), or it has already been recorded as part of a
1804 * previous match.
1805 */
1806 return;
1807 }
1808
1809 bool needs_flat_qualifier = consumer_var == NULL__null &&
1810 (producer_var->type->contains_integer() ||
1811 producer_var->type->contains_double());
1812
1813 if (!disable_varying_packing &&
1814 (!disable_xfb_packing || producer_var == NULL__null || !producer_var->data.is_xfb) &&
1815 (needs_flat_qualifier ||
1816 (consumer_stage != MESA_SHADER_NONE && consumer_stage != MESA_SHADER_FRAGMENT))) {
1817 /* Since this varying is not being consumed by the fragment shader, its
1818 * interpolation type varying cannot possibly affect rendering.
1819 * Also, this variable is non-flat and is (or contains) an integer
1820 * or a double.
1821 * If the consumer stage is unknown, don't modify the interpolation
1822 * type as it could affect rendering later with separate shaders.
1823 *
1824 * lower_packed_varyings requires all integer varyings to flat,
1825 * regardless of where they appear. We can trivially satisfy that
1826 * requirement by changing the interpolation type to flat here.
1827 */
1828 if (producer_var) {
1829 producer_var->data.centroid = false;
1830 producer_var->data.sample = false;
1831 producer_var->data.interpolation = INTERP_MODE_FLAT;
1832 }
1833
1834 if (consumer_var) {
1835 consumer_var->data.centroid = false;
1836 consumer_var->data.sample = false;
1837 consumer_var->data.interpolation = INTERP_MODE_FLAT;
1838 }
1839 }
1840
1841 if (this->num_matches == this->matches_capacity) {
1842 this->matches_capacity *= 2;
1843 this->matches = (match *)
1844 realloc(this->matches,
1845 sizeof(*this->matches) * this->matches_capacity);
1846 }
1847
1848 /* We must use the consumer to compute the packing class because in GL4.4+
1849 * there is no guarantee interpolation qualifiers will match across stages.
1850 *
1851 * From Section 4.5 (Interpolation Qualifiers) of the GLSL 4.30 spec:
1852 *
1853 * "The type and presence of interpolation qualifiers of variables with
1854 * the same name declared in all linked shaders for the same cross-stage
1855 * interface must match, otherwise the link command will fail.
1856 *
1857 * When comparing an output from one stage to an input of a subsequent
1858 * stage, the input and output don't match if their interpolation
1859 * qualifiers (or lack thereof) are not the same."
1860 *
1861 * This text was also in at least revison 7 of the 4.40 spec but is no
1862 * longer in revision 9 and not in the 4.50 spec.
1863 */
1864 const ir_variable *const var = (consumer_var != NULL__null)
1865 ? consumer_var : producer_var;
1866 const gl_shader_stage stage = (consumer_var != NULL__null)
1867 ? consumer_stage : producer_stage;
1868 const glsl_type *type = get_varying_type(var, stage);
1869
1870 if (producer_var && consumer_var &&
1871 consumer_var->data.must_be_shader_input) {
1872 producer_var->data.must_be_shader_input = 1;
1873 }
1874
1875 this->matches[this->num_matches].packing_class
1876 = this->compute_packing_class(var);
1877 this->matches[this->num_matches].packing_order
1878 = this->compute_packing_order(var);
1879 if ((this->disable_varying_packing && !is_varying_packing_safe(type, var)) ||
1880 (this->disable_xfb_packing && var->data.is_xfb) ||
1881 var->data.must_be_shader_input) {
1882 unsigned slots = type->count_attribute_slots(false);
1883 this->matches[this->num_matches].num_components = slots * 4;
1884 } else {
1885 this->matches[this->num_matches].num_components
1886 = type->component_slots();
1887 }
1888
1889 this->matches[this->num_matches].producer_var = producer_var;
1890 this->matches[this->num_matches].consumer_var = consumer_var;
1891 this->num_matches++;
1892 if (producer_var)
1893 producer_var->data.is_unmatched_generic_inout = 0;
1894 if (consumer_var)
1895 consumer_var->data.is_unmatched_generic_inout = 0;
1896}
1897
1898
1899/**
1900 * Choose locations for all of the variable matches that were previously
1901 * passed to varying_matches::record().
1902 * \param components returns array[slot] of number of components used
1903 * per slot (1, 2, 3 or 4)
1904 * \param reserved_slots bitmask indicating which varying slots are already
1905 * allocated
1906 * \return number of slots (4-element vectors) allocated
1907 */
1908unsigned
1909varying_matches::assign_locations(struct gl_shader_program *prog,
1910 uint8_t components[],
1911 uint64_t reserved_slots)
1912{
1913 /* If packing has been disabled then we cannot safely sort the varyings by
1914 * class as it may mean we are using a version of OpenGL where
1915 * interpolation qualifiers are not guaranteed to be matching across
1916 * shaders, sorting in this case could result in mismatching shader
1917 * interfaces.
1918 * When packing is disabled the sort orders varyings used by transform
1919 * feedback first, but also depends on *undefined behaviour* of qsort to
1920 * reverse the order of the varyings. See: xfb_comparator().
1921 *
1922 * If packing is only disabled for xfb varyings (mutually exclusive with
1923 * disable_varying_packing), we then group varyings depending on if they
1924 * are captured for transform feedback. The same *undefined behaviour* is
1925 * taken advantage of.
1926 */
1927 if (this->disable_varying_packing) {
1928 /* Only sort varyings that are only used by transform feedback. */
1929 qsort(this->matches, this->num_matches, sizeof(*this->matches),
1930 &varying_matches::xfb_comparator);
1931 } else if (this->disable_xfb_packing) {
1932 /* Only sort varyings that are NOT used by transform feedback. */
1933 qsort(this->matches, this->num_matches, sizeof(*this->matches),
1934 &varying_matches::not_xfb_comparator);
1935 } else {
1936 /* Sort varying matches into an order that makes them easy to pack. */
1937 qsort(this->matches, this->num_matches, sizeof(*this->matches),
1938 &varying_matches::match_comparator);
1939 }
1940
1941 unsigned generic_location = 0;
1942 unsigned generic_patch_location = MAX_VARYING32*4;
1943 bool previous_var_xfb = false;
1944 bool previous_var_xfb_only = false;
1945 unsigned previous_packing_class = ~0u;
1946
1947 /* For tranform feedback separate mode, we know the number of attributes
1948 * is <= the number of buffers. So packing isn't critical. In fact,
1949 * packing vec3 attributes can cause trouble because splitting a vec3
1950 * effectively creates an additional transform feedback output. The
1951 * extra TFB output may exceed device driver limits.
1952 */
1953 const bool dont_pack_vec3 =
1954 (prog->TransformFeedback.BufferMode == GL_SEPARATE_ATTRIBS0x8C8D &&
1955 prog->TransformFeedback.NumVarying > 0);
1956
1957 for (unsigned i = 0; i < this->num_matches; i++) {
1958 unsigned *location = &generic_location;
1959 const ir_variable *var;
1960 const glsl_type *type;
1961 bool is_vertex_input = false;
1962
1963 if (matches[i].consumer_var) {
1964 var = matches[i].consumer_var;
1965 type = get_varying_type(var, consumer_stage);
1966 if (consumer_stage == MESA_SHADER_VERTEX)
1967 is_vertex_input = true;
1968 } else {
1969 var = matches[i].producer_var;
1970 type = get_varying_type(var, producer_stage);
1971 }
1972
1973 if (var->data.patch)
1974 location = &generic_patch_location;
1975
1976 /* Advance to the next slot if this varying has a different packing
1977 * class than the previous one, and we're not already on a slot
1978 * boundary.
1979 *
1980 * Also advance if varying packing is disabled for transform feedback,
1981 * and previous or current varying is used for transform feedback.
1982 *
1983 * Also advance to the next slot if packing is disabled. This makes sure
1984 * we don't assign varyings the same locations which is possible
1985 * because we still pack individual arrays, records and matrices even
1986 * when packing is disabled. Note we don't advance to the next slot if
1987 * we can pack varyings together that are only used for transform
1988 * feedback.
1989 */
1990 if (var->data.must_be_shader_input ||
1991 (this->disable_xfb_packing &&
1992 (previous_var_xfb || var->data.is_xfb)) ||
1993 (this->disable_varying_packing &&
1994 !(previous_var_xfb_only && var->data.is_xfb_only)) ||
1995 (previous_packing_class != this->matches[i].packing_class) ||
1996 (this->matches[i].packing_order == PACKING_ORDER_VEC3 &&
1997 dont_pack_vec3)) {
1998 *location = ALIGN(*location, 4);
1999 }
2000
2001 previous_var_xfb = var->data.is_xfb;
2002 previous_var_xfb_only = var->data.is_xfb_only;
2003 previous_packing_class = this->matches[i].packing_class;
2004
2005 /* The number of components taken up by this variable. For vertex shader
2006 * inputs, we use the number of slots * 4, as they have different
2007 * counting rules.
2008 */
2009 unsigned num_components = is_vertex_input ?
2010 type->count_attribute_slots(is_vertex_input) * 4 :
2011 this->matches[i].num_components;
2012
2013 /* The last slot for this variable, inclusive. */
2014 unsigned slot_end = *location + num_components - 1;
2015
2016 /* FIXME: We could be smarter in the below code and loop back over
2017 * trying to fill any locations that we skipped because we couldn't pack
2018 * the varying between an explicit location. For now just let the user
2019 * hit the linking error if we run out of room and suggest they use
2020 * explicit locations.
2021 */
2022 while (slot_end < MAX_VARYING32 * 4u) {
2023 const unsigned slots = (slot_end / 4u) - (*location / 4u) + 1;
2024 const uint64_t slot_mask = ((1ull << slots) - 1) << (*location / 4u);
2025
2026 assert(slots > 0)(static_cast <bool> (slots > 0) ? void (0) : __assert_fail
("slots > 0", __builtin_FILE (), __builtin_LINE (), __extension__
__PRETTY_FUNCTION__));
2027
2028 if ((reserved_slots & slot_mask) == 0) {
2029 break;
2030 }
2031
2032 *location = ALIGN(*location + 1, 4);
2033 slot_end = *location + num_components - 1;
2034 }
2035
2036 if (!var->data.patch && slot_end >= MAX_VARYING32 * 4u) {
2037 linker_error(prog, "insufficient contiguous locations available for "
2038 "%s it is possible an array or struct could not be "
2039 "packed between varyings with explicit locations. Try "
2040 "using an explicit location for arrays and structs.",
2041 var->name);
2042 }
2043
2044 if (slot_end < MAX_VARYINGS_INCL_PATCH((((VARYING_SLOT_VAR0 + 32)) + 32) - VARYING_SLOT_VAR0) * 4u) {
2045 for (unsigned j = *location / 4u; j < slot_end / 4u; j++)
2046 components[j] = 4;
2047 components[slot_end / 4u] = (slot_end & 3) + 1;
2048 }
2049
2050 this->matches[i].generic_location = *location;
2051
2052 *location = slot_end + 1;
2053 }
2054
2055 return (generic_location + 3) / 4;
2056}
2057
2058
2059/**
2060 * Update the producer and consumer shaders to reflect the locations
2061 * assignments that were made by varying_matches::assign_locations().
2062 */
2063void
2064varying_matches::store_locations() const
2065{
2066 /* Check is location needs to be packed with lower_packed_varyings() or if
2067 * we can just use ARB_enhanced_layouts packing.
2068 */
2069 bool pack_loc[MAX_VARYINGS_INCL_PATCH((((VARYING_SLOT_VAR0 + 32)) + 32) - VARYING_SLOT_VAR0)] = { 0 };
2070 const glsl_type *loc_type[MAX_VARYINGS_INCL_PATCH((((VARYING_SLOT_VAR0 + 32)) + 32) - VARYING_SLOT_VAR0)][4] = { {NULL__null, NULL__null} };
2071
2072 for (unsigned i = 0; i < this->num_matches; i++) {
2073 ir_variable *producer_var = this->matches[i].producer_var;
2074 ir_variable *consumer_var = this->matches[i].consumer_var;
2075 unsigned generic_location = this->matches[i].generic_location;
2076 unsigned slot = generic_location / 4;
2077 unsigned offset = generic_location % 4;
2078
2079 if (producer_var) {
2080 producer_var->data.location = VARYING_SLOT_VAR0 + slot;
2081 producer_var->data.location_frac = offset;
2082 }
2083
2084 if (consumer_var) {
2085 assert(consumer_var->data.location == -1)(static_cast <bool> (consumer_var->data.location == -
1) ? void (0) : __assert_fail ("consumer_var->data.location == -1"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
2086 consumer_var->data.location = VARYING_SLOT_VAR0 + slot;
2087 consumer_var->data.location_frac = offset;
2088 }
2089
2090 /* Find locations suitable for native packing via
2091 * ARB_enhanced_layouts.
2092 */
2093 if (producer_var && consumer_var) {
2094 if (enhanced_layouts_enabled) {
2095 const glsl_type *type =
2096 get_varying_type(producer_var, producer_stage);
2097 if (type->is_array() || type->is_matrix() || type->is_struct() ||
2098 type->is_64bit()) {
2099 unsigned comp_slots = type->component_slots() + offset;
2100 unsigned slots = comp_slots / 4;
2101 if (comp_slots % 4)
2102 slots += 1;
2103
2104 for (unsigned j = 0; j < slots; j++) {
2105 pack_loc[slot + j] = true;
2106 }
2107 } else if (offset + type->vector_elements > 4) {
2108 pack_loc[slot] = true;
2109 pack_loc[slot + 1] = true;
2110 } else {
2111 loc_type[slot][offset] = type;
2112 }
2113 }
2114 }
2115 }
2116
2117 /* Attempt to use ARB_enhanced_layouts for more efficient packing if
2118 * suitable.
2119 */
2120 if (enhanced_layouts_enabled) {
2121 for (unsigned i = 0; i < this->num_matches; i++) {
2122 ir_variable *producer_var = this->matches[i].producer_var;
2123 ir_variable *consumer_var = this->matches[i].consumer_var;
2124 unsigned generic_location = this->matches[i].generic_location;
2125 unsigned slot = generic_location / 4;
2126
2127 if (pack_loc[slot] || !producer_var || !consumer_var)
2128 continue;
2129
2130 const glsl_type *type =
2131 get_varying_type(producer_var, producer_stage);
2132 bool type_match = true;
2133 for (unsigned j = 0; j < 4; j++) {
2134 if (loc_type[slot][j]) {
2135 if (type->base_type != loc_type[slot][j]->base_type)
2136 type_match = false;
2137 }
2138 }
2139
2140 if (type_match) {
2141 producer_var->data.explicit_location = 1;
2142 consumer_var->data.explicit_location = 1;
2143 producer_var->data.explicit_component = 1;
2144 consumer_var->data.explicit_component = 1;
2145 }
2146 }
2147 }
2148}
2149
2150
2151/**
2152 * Compute the "packing class" of the given varying. This is an unsigned
2153 * integer with the property that two variables in the same packing class can
2154 * be safely backed into the same vec4.
2155 */
2156unsigned
2157varying_matches::compute_packing_class(const ir_variable *var)
2158{
2159 /* Without help from the back-end, there is no way to pack together
2160 * variables with different interpolation types, because
2161 * lower_packed_varyings must choose exactly one interpolation type for
2162 * each packed varying it creates.
2163 *
2164 * However, we can safely pack together floats, ints, and uints, because:
2165 *
2166 * - varyings of base type "int" and "uint" must use the "flat"
2167 * interpolation type, which can only occur in GLSL 1.30 and above.
2168 *
2169 * - On platforms that support GLSL 1.30 and above, lower_packed_varyings
2170 * can store flat floats as ints without losing any information (using
2171 * the ir_unop_bitcast_* opcodes).
2172 *
2173 * Therefore, the packing class depends only on the interpolation type.
2174 */
2175 const unsigned interp = var->is_interpolation_flat()
2176 ? unsigned(INTERP_MODE_FLAT) : var->data.interpolation;
2177
2178 assert(interp < (1 << 3))(static_cast <bool> (interp < (1 << 3)) ? void
(0) : __assert_fail ("interp < (1 << 3)", __builtin_FILE
(), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__));
2179
2180 const unsigned packing_class = (interp << 0) |
2181 (var->data.centroid << 3) |
2182 (var->data.sample << 4) |
2183 (var->data.patch << 5) |
2184 (var->data.must_be_shader_input << 6);
2185
2186 return packing_class;
2187}
2188
2189
2190/**
2191 * Compute the "packing order" of the given varying. This is a sort key we
2192 * use to determine when to attempt to pack the given varying relative to
2193 * other varyings in the same packing class.
2194 */
2195varying_matches::packing_order_enum
2196varying_matches::compute_packing_order(const ir_variable *var)
2197{
2198 const glsl_type *element_type = var->type;
2199
2200 while (element_type->is_array()) {
2201 element_type = element_type->fields.array;
2202 }
2203
2204 switch (element_type->component_slots() % 4) {
2205 case 1: return PACKING_ORDER_SCALAR;
2206 case 2: return PACKING_ORDER_VEC2;
2207 case 3: return PACKING_ORDER_VEC3;
2208 case 0: return PACKING_ORDER_VEC4;
2209 default:
2210 assert(!"Unexpected value of vector_elements")(static_cast <bool> (!"Unexpected value of vector_elements"
) ? void (0) : __assert_fail ("!\"Unexpected value of vector_elements\""
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
2211 return PACKING_ORDER_VEC4;
2212 }
2213}
2214
2215
2216/**
2217 * Comparison function passed to qsort() to sort varyings by packing_class and
2218 * then by packing_order.
2219 */
2220int
2221varying_matches::match_comparator(const void *x_generic, const void *y_generic)
2222{
2223 const match *x = (const match *) x_generic;
2224 const match *y = (const match *) y_generic;
2225
2226 if (x->packing_class != y->packing_class)
2227 return x->packing_class - y->packing_class;
2228 return x->packing_order - y->packing_order;
2229}
2230
2231
2232/**
2233 * Comparison function passed to qsort() to sort varyings used only by
2234 * transform feedback when packing of other varyings is disabled.
2235 */
2236int
2237varying_matches::xfb_comparator(const void *x_generic, const void *y_generic)
2238{
2239 const match *x = (const match *) x_generic;
2240
2241 if (x->producer_var != NULL__null && x->producer_var->data.is_xfb_only)
2242 return match_comparator(x_generic, y_generic);
2243
2244 /* FIXME: When the comparator returns 0 it means the elements being
2245 * compared are equivalent. However the qsort documentation says:
2246 *
2247 * "The order of equivalent elements is undefined."
2248 *
2249 * In practice the sort ends up reversing the order of the varyings which
2250 * means locations are also assigned in this reversed order and happens to
2251 * be what we want. This is also whats happening in
2252 * varying_matches::match_comparator().
2253 */
2254 return 0;
2255}
2256
2257
2258/**
2259 * Comparison function passed to qsort() to sort varyings NOT used by
2260 * transform feedback when packing of xfb varyings is disabled.
2261 */
2262int
2263varying_matches::not_xfb_comparator(const void *x_generic, const void *y_generic)
2264{
2265 const match *x = (const match *) x_generic;
2266
2267 if (x->producer_var != NULL__null && !x->producer_var->data.is_xfb)
2268 return match_comparator(x_generic, y_generic);
2269
2270 /* FIXME: When the comparator returns 0 it means the elements being
2271 * compared are equivalent. However the qsort documentation says:
2272 *
2273 * "The order of equivalent elements is undefined."
2274 *
2275 * In practice the sort ends up reversing the order of the varyings which
2276 * means locations are also assigned in this reversed order and happens to
2277 * be what we want. This is also whats happening in
2278 * varying_matches::match_comparator().
2279 */
2280 return 0;
2281}
2282
2283
2284/**
2285 * Is the given variable a varying variable to be counted against the
2286 * limit in ctx->Const.MaxVarying?
2287 * This includes variables such as texcoords, colors and generic
2288 * varyings, but excludes variables such as gl_FrontFacing and gl_FragCoord.
2289 */
2290static bool
2291var_counts_against_varying_limit(gl_shader_stage stage, const ir_variable *var)
2292{
2293 /* Only fragment shaders will take a varying variable as an input */
2294 if (stage == MESA_SHADER_FRAGMENT &&
2295 var->data.mode == ir_var_shader_in) {
2296 switch (var->data.location) {
2297 case VARYING_SLOT_POS:
2298 case VARYING_SLOT_FACE:
2299 case VARYING_SLOT_PNTC:
2300 return false;
2301 default:
2302 return true;
2303 }
2304 }
2305 return false;
2306}
2307
2308
2309/**
2310 * Visitor class that generates tfeedback_candidate structs describing all
2311 * possible targets of transform feedback.
2312 *
2313 * tfeedback_candidate structs are stored in the hash table
2314 * tfeedback_candidates, which is passed to the constructor. This hash table
2315 * maps varying names to instances of the tfeedback_candidate struct.
2316 */
2317class tfeedback_candidate_generator : public program_resource_visitor
2318{
2319public:
2320 tfeedback_candidate_generator(void *mem_ctx,
2321 hash_table *tfeedback_candidates,
2322 gl_shader_stage stage)
2323 : mem_ctx(mem_ctx),
2324 tfeedback_candidates(tfeedback_candidates),
2325 stage(stage),
2326 toplevel_var(NULL__null),
2327 varying_floats(0)
2328 {
2329 }
2330
2331 void process(ir_variable *var)
2332 {
2333 /* All named varying interface blocks should be flattened by now */
2334 assert(!var->is_interface_instance())(static_cast <bool> (!var->is_interface_instance()) ?
void (0) : __assert_fail ("!var->is_interface_instance()"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
2335 assert(var->data.mode == ir_var_shader_out)(static_cast <bool> (var->data.mode == ir_var_shader_out
) ? void (0) : __assert_fail ("var->data.mode == ir_var_shader_out"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
2336
2337 this->toplevel_var = var;
2338 this->varying_floats = 0;
2339 const glsl_type *t =
2340 var->data.from_named_ifc_block ? var->get_interface_type() : var->type;
2341 if (!var->data.patch && stage == MESA_SHADER_TESS_CTRL) {
2342 assert(t->is_array())(static_cast <bool> (t->is_array()) ? void (0) : __assert_fail
("t->is_array()", __builtin_FILE (), __builtin_LINE (), __extension__
__PRETTY_FUNCTION__));
2343 t = t->fields.array;
2344 }
2345 program_resource_visitor::process(var, t, false);
2346 }
2347
2348private:
2349 virtual void visit_field(const glsl_type *type, const char *name,
2350 bool /* row_major */,
2351 const glsl_type * /* record_type */,
2352 const enum glsl_interface_packing,
2353 bool /* last_field */)
2354 {
2355 assert(!type->without_array()->is_struct())(static_cast <bool> (!type->without_array()->is_struct
()) ? void (0) : __assert_fail ("!type->without_array()->is_struct()"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
2356 assert(!type->without_array()->is_interface())(static_cast <bool> (!type->without_array()->is_interface
()) ? void (0) : __assert_fail ("!type->without_array()->is_interface()"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
2357
2358 tfeedback_candidate *candidate
2359 = rzalloc(this->mem_ctx, tfeedback_candidate)((tfeedback_candidate *) rzalloc_size(this->mem_ctx, sizeof
(tfeedback_candidate)));
2360 candidate->toplevel_var = this->toplevel_var;
2361 candidate->type = type;
2362 candidate->offset = this->varying_floats;
2363 _mesa_hash_table_insert(this->tfeedback_candidates,
2364 ralloc_strdup(this->mem_ctx, name),
2365 candidate);
2366 this->varying_floats += type->component_slots();
2367 }
2368
2369 /**
2370 * Memory context used to allocate hash table keys and values.
2371 */
2372 void * const mem_ctx;
2373
2374 /**
2375 * Hash table in which tfeedback_candidate objects should be stored.
2376 */
2377 hash_table * const tfeedback_candidates;
2378
2379 gl_shader_stage stage;
2380
2381 /**
2382 * Pointer to the toplevel variable that is being traversed.
2383 */
2384 ir_variable *toplevel_var;
2385
2386 /**
2387 * Total number of varying floats that have been visited so far. This is
2388 * used to determine the offset to each varying within the toplevel
2389 * variable.
2390 */
2391 unsigned varying_floats;
2392};
2393
2394
2395namespace linker {
2396
2397void
2398populate_consumer_input_sets(void *mem_ctx, exec_list *ir,
2399 hash_table *consumer_inputs,
2400 hash_table *consumer_interface_inputs,
2401 ir_variable *consumer_inputs_with_locations[VARYING_SLOT_TESS_MAX(((VARYING_SLOT_VAR0 + 32)) + 32)])
2402{
2403 memset(consumer_inputs_with_locations,
2404 0,
2405 sizeof(consumer_inputs_with_locations[0]) * VARYING_SLOT_TESS_MAX(((VARYING_SLOT_VAR0 + 32)) + 32));
2406
2407 foreach_in_list(ir_instruction, node, ir)for (ir_instruction *node = (!exec_node_is_tail_sentinel((ir)
->head_sentinel.next) ? (ir_instruction *) ((ir)->head_sentinel
.next) : __null); (node) != __null; (node) = (!exec_node_is_tail_sentinel
((node)->next) ? (ir_instruction *) ((node)->next) : __null
)) {
2408 ir_variable *const input_var = node->as_variable();
2409
2410 if (input_var != NULL__null && input_var->data.mode == ir_var_shader_in) {
2411 /* All interface blocks should have been lowered by this point */
2412 assert(!input_var->type->is_interface())(static_cast <bool> (!input_var->type->is_interface
()) ? void (0) : __assert_fail ("!input_var->type->is_interface()"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
2413
2414 if (input_var->data.explicit_location) {
2415 /* assign_varying_locations only cares about finding the
2416 * ir_variable at the start of a contiguous location block.
2417 *
2418 * - For !producer, consumer_inputs_with_locations isn't used.
2419 *
2420 * - For !consumer, consumer_inputs_with_locations is empty.
2421 *
2422 * For consumer && producer, if you were trying to set some
2423 * ir_variable to the middle of a location block on the other side
2424 * of producer/consumer, cross_validate_outputs_to_inputs() should
2425 * be link-erroring due to either type mismatch or location
2426 * overlaps. If the variables do match up, then they've got a
2427 * matching data.location and you only looked at
2428 * consumer_inputs_with_locations[var->data.location], not any
2429 * following entries for the array/structure.
2430 */
2431 consumer_inputs_with_locations[input_var->data.location] =
2432 input_var;
2433 } else if (input_var->get_interface_type() != NULL__null) {
2434 char *const iface_field_name =
2435 ralloc_asprintf(mem_ctx, "%s.%s",
2436 input_var->get_interface_type()->without_array()->name,
2437 input_var->name);
2438 _mesa_hash_table_insert(consumer_interface_inputs,
2439 iface_field_name, input_var);
2440 } else {
2441 _mesa_hash_table_insert(consumer_inputs,
2442 ralloc_strdup(mem_ctx, input_var->name),
2443 input_var);
2444 }
2445 }
2446 }
2447}
2448
2449/**
2450 * Find a variable from the consumer that "matches" the specified variable
2451 *
2452 * This function only finds inputs with names that match. There is no
2453 * validation (here) that the types, etc. are compatible.
2454 */
2455ir_variable *
2456get_matching_input(void *mem_ctx,
2457 const ir_variable *output_var,
2458 hash_table *consumer_inputs,
2459 hash_table *consumer_interface_inputs,
2460 ir_variable *consumer_inputs_with_locations[VARYING_SLOT_TESS_MAX(((VARYING_SLOT_VAR0 + 32)) + 32)])
2461{
2462 ir_variable *input_var;
2463
2464 if (output_var->data.explicit_location) {
2465 input_var = consumer_inputs_with_locations[output_var->data.location];
2466 } else if (output_var->get_interface_type() != NULL__null) {
2467 char *const iface_field_name =
2468 ralloc_asprintf(mem_ctx, "%s.%s",
2469 output_var->get_interface_type()->without_array()->name,
2470 output_var->name);
2471 hash_entry *entry = _mesa_hash_table_search(consumer_interface_inputs, iface_field_name);
2472 input_var = entry ? (ir_variable *) entry->data : NULL__null;
2473 } else {
2474 hash_entry *entry = _mesa_hash_table_search(consumer_inputs, output_var->name);
2475 input_var = entry ? (ir_variable *) entry->data : NULL__null;
2476 }
2477
2478 return (input_var == NULL__null || input_var->data.mode != ir_var_shader_in)
2479 ? NULL__null : input_var;
2480}
2481
2482}
2483
2484static int
2485io_variable_cmp(const void *_a, const void *_b)
2486{
2487 const ir_variable *const a = *(const ir_variable **) _a;
2488 const ir_variable *const b = *(const ir_variable **) _b;
2489
2490 if (a->data.explicit_location && b->data.explicit_location)
2491 return b->data.location - a->data.location;
2492
2493 if (a->data.explicit_location && !b->data.explicit_location)
2494 return 1;
2495
2496 if (!a->data.explicit_location && b->data.explicit_location)
2497 return -1;
2498
2499 return -strcmp(a->name, b->name);
2500}
2501
2502/**
2503 * Sort the shader IO variables into canonical order
2504 */
2505static void
2506canonicalize_shader_io(exec_list *ir, enum ir_variable_mode io_mode)
2507{
2508 ir_variable *var_table[MAX_PROGRAM_OUTPUTS64 * 4];
2509 unsigned num_variables = 0;
2510
2511 foreach_in_list(ir_instruction, node, ir)for (ir_instruction *node = (!exec_node_is_tail_sentinel((ir)
->head_sentinel.next) ? (ir_instruction *) ((ir)->head_sentinel
.next) : __null); (node) != __null; (node) = (!exec_node_is_tail_sentinel
((node)->next) ? (ir_instruction *) ((node)->next) : __null
)) {
2512 ir_variable *const var = node->as_variable();
2513
2514 if (var == NULL__null || var->data.mode != io_mode)
2515 continue;
2516
2517 /* If we have already encountered more I/O variables that could
2518 * successfully link, bail.
2519 */
2520 if (num_variables == ARRAY_SIZE(var_table)(sizeof(var_table) / sizeof((var_table)[0])))
2521 return;
2522
2523 var_table[num_variables++] = var;
2524 }
2525
2526 if (num_variables == 0)
2527 return;
2528
2529 /* Sort the list in reverse order (io_variable_cmp handles this). Later
2530 * we're going to push the variables on to the IR list as a stack, so we
2531 * want the last variable (in canonical order) to be first in the list.
2532 */
2533 qsort(var_table, num_variables, sizeof(var_table[0]), io_variable_cmp);
2534
2535 /* Remove the variable from it's current location in the IR, and put it at
2536 * the front.
2537 */
2538 for (unsigned i = 0; i < num_variables; i++) {
2539 var_table[i]->remove();
2540 ir->push_head(var_table[i]);
2541 }
2542}
2543
2544/**
2545 * Generate a bitfield map of the explicit locations for shader varyings.
2546 *
2547 * Note: For Tessellation shaders we are sitting right on the limits of the
2548 * 64 bit map. Per-vertex and per-patch both have separate location domains
2549 * with a max of MAX_VARYING.
2550 */
2551static uint64_t
2552reserved_varying_slot(struct gl_linked_shader *stage,
2553 ir_variable_mode io_mode)
2554{
2555 assert(io_mode == ir_var_shader_in || io_mode == ir_var_shader_out)(static_cast <bool> (io_mode == ir_var_shader_in || io_mode
== ir_var_shader_out) ? void (0) : __assert_fail ("io_mode == ir_var_shader_in || io_mode == ir_var_shader_out"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
2556 /* Avoid an overflow of the returned value */
2557 assert(MAX_VARYINGS_INCL_PATCH <= 64)(static_cast <bool> (((((VARYING_SLOT_VAR0 + 32)) + 32)
- VARYING_SLOT_VAR0) <= 64) ? void (0) : __assert_fail ("MAX_VARYINGS_INCL_PATCH <= 64"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
2558
2559 uint64_t slots = 0;
2560 int var_slot;
2561
2562 if (!stage)
2563 return slots;
2564
2565 foreach_in_list(ir_instruction, node, stage->ir)for (ir_instruction *node = (!exec_node_is_tail_sentinel((stage
->ir)->head_sentinel.next) ? (ir_instruction *) ((stage
->ir)->head_sentinel.next) : __null); (node) != __null;
(node) = (!exec_node_is_tail_sentinel((node)->next) ? (ir_instruction
*) ((node)->next) : __null)) {
2566 ir_variable *const var = node->as_variable();
2567
2568 if (var == NULL__null || var->data.mode != io_mode ||
2569 !var->data.explicit_location ||
2570 var->data.location < VARYING_SLOT_VAR0)
2571 continue;
2572
2573 var_slot = var->data.location - VARYING_SLOT_VAR0;
2574
2575 unsigned num_elements = get_varying_type(var, stage->Stage)
2576 ->count_attribute_slots(io_mode == ir_var_shader_in &&
2577 stage->Stage == MESA_SHADER_VERTEX);
2578 for (unsigned i = 0; i < num_elements; i++) {
2579 if (var_slot >= 0 && var_slot < MAX_VARYINGS_INCL_PATCH((((VARYING_SLOT_VAR0 + 32)) + 32) - VARYING_SLOT_VAR0))
2580 slots |= UINT64_C(1)1UL << var_slot;
2581 var_slot += 1;
2582 }
2583 }
2584
2585 return slots;
2586}
2587
2588
2589/**
2590 * Assign locations for all variables that are produced in one pipeline stage
2591 * (the "producer") and consumed in the next stage (the "consumer").
2592 *
2593 * Variables produced by the producer may also be consumed by transform
2594 * feedback.
2595 *
2596 * \param num_tfeedback_decls is the number of declarations indicating
2597 * variables that may be consumed by transform feedback.
2598 *
2599 * \param tfeedback_decls is a pointer to an array of tfeedback_decl objects
2600 * representing the result of parsing the strings passed to
2601 * glTransformFeedbackVaryings(). assign_location() will be called for
2602 * each of these objects that matches one of the outputs of the
2603 * producer.
2604 *
2605 * When num_tfeedback_decls is nonzero, it is permissible for the consumer to
2606 * be NULL. In this case, varying locations are assigned solely based on the
2607 * requirements of transform feedback.
2608 */
2609static bool
2610assign_varying_locations(struct gl_context *ctx,
2611 void *mem_ctx,
2612 struct gl_shader_program *prog,
2613 gl_linked_shader *producer,
2614 gl_linked_shader *consumer,
2615 unsigned num_tfeedback_decls,
2616 tfeedback_decl *tfeedback_decls,
2617 const uint64_t reserved_slots)
2618{
2619 /* Tessellation shaders treat inputs and outputs as shared memory and can
2620 * access inputs and outputs of other invocations.
2621 * Therefore, they can't be lowered to temps easily (and definitely not
2622 * efficiently).
2623 */
2624 bool unpackable_tess =
2625 (consumer && consumer->Stage == MESA_SHADER_TESS_EVAL) ||
1
Assuming 'consumer' is null
→
2626 (consumer
1.1
'consumer' is null
 && consumer->Stage == MESA_SHADER_TESS_CTRL) ||
2627 (producer && producer->Stage == MESA_SHADER_TESS_CTRL);
2
←
Assuming 'producer' is null
→
2628
2629 /* Transform feedback code assumes varying arrays are packed, so if the
2630 * driver has disabled varying packing, make sure to at least enable
2631 * packing required by transform feedback. See below for exception.
2632 */
2633 bool xfb_enabled =
2634 ctx->Extensions.EXT_transform_feedback && !unpackable_tess;
3
←
Assuming field 'EXT_transform_feedback' is 0
→
2635
2636 /* Some drivers actually requires packing to be explicitly disabled
2637 * for varyings used by transform feedback.
2638 */
2639 bool disable_xfb_packing =
2640 ctx->Const.DisableTransformFeedbackPacking;
2641
2642 /* Disable packing on outward facing interfaces for SSO because in ES we
2643 * need to retain the unpacked varying information for draw time
2644 * validation.
2645 *
2646 * Packing is still enabled on individual arrays, structs, and matrices as
2647 * these are required by the transform feedback code and it is still safe
2648 * to do so. We also enable packing when a varying is only used for
2649 * transform feedback and its not a SSO.
2650 */
2651 bool disable_varying_packing =
2652 ctx->Const.DisableVaryingPacking || unpackable_tess;
4
←
Assuming field 'DisableVaryingPacking' is not equal to 0
→
2653 if (prog->SeparateShader && (producer == NULL__null || consumer == NULL__null))
5
←
Assuming field 'SeparateShader' is 0
→
2654 disable_varying_packing = true;
2655
2656 varying_matches matches(disable_varying_packing,
6
←
'?' condition is false
→
2657 disable_xfb_packing,
2658 xfb_enabled,
2659 ctx->Extensions.ARB_enhanced_layouts,
2660 producer
5.1
'producer' is null
 ? producer->Stage : MESA_SHADER_NONE,
2661 consumer
6.1
'consumer' is null
 ? consumer->Stage : MESA_SHADER_NONE);
7
←
'?' condition is false
→
2662 void *hash_table_ctx = ralloc_context(NULL__null);
2663 hash_table *tfeedback_candidates =
2664 _mesa_hash_table_create(hash_table_ctx, _mesa_hash_string,
2665 _mesa_key_string_equal);
2666 hash_table *consumer_inputs =
2667 _mesa_hash_table_create(hash_table_ctx, _mesa_hash_string,
2668 _mesa_key_string_equal);
2669 hash_table *consumer_interface_inputs =
2670 _mesa_hash_table_create(hash_table_ctx, _mesa_hash_string,
2671 _mesa_key_string_equal);
2672 ir_variable *consumer_inputs_with_locations[VARYING_SLOT_TESS_MAX(((VARYING_SLOT_VAR0 + 32)) + 32)] = {
2673 NULL__null,
2674 };
2675
2676 unsigned consumer_vertices = 0;
2677 if (consumer
7.1
'consumer' is null
 && consumer->Stage == MESA_SHADER_GEOMETRY)
2678 consumer_vertices = prog->Geom.VerticesIn;
2679
2680 /* Operate in a total of four passes.
2681 *
2682 * 1. Sort inputs / outputs into a canonical order. This is necessary so
2683 * that inputs / outputs of separable shaders will be assigned
2684 * predictable locations regardless of the order in which declarations
2685 * appeared in the shader source.
2686 *
2687 * 2. Assign locations for any matching inputs and outputs.
2688 *
2689 * 3. Mark output variables in the producer that do not have locations as
2690 * not being outputs. This lets the optimizer eliminate them.
2691 *
2692 * 4. Mark input variables in the consumer that do not have locations as
2693 * not being inputs. This lets the optimizer eliminate them.
2694 */
2695 if (consumer
7.2
'consumer' is null
)
8
←
Taking false branch
→
2696 canonicalize_shader_io(consumer->ir, ir_var_shader_in);
2697
2698 if (producer
8.1
'producer' is null
)
9
←
Taking false branch
→
2699 canonicalize_shader_io(producer->ir, ir_var_shader_out);
2700
2701 if (consumer
9.1
'consumer' is null
)
10
←
Taking false branch
→
2702 linker::populate_consumer_input_sets(mem_ctx, consumer->ir,
2703 consumer_inputs,
2704 consumer_interface_inputs,
2705 consumer_inputs_with_locations);
2706
2707 if (producer
10.1
'producer' is null
) {
2708 foreach_in_list(ir_instruction, node, producer->ir)for (ir_instruction *node = (!exec_node_is_tail_sentinel((producer
->ir)->head_sentinel.next) ? (ir_instruction *) ((producer
->ir)->head_sentinel.next) : __null); (node) != __null;
(node) = (!exec_node_is_tail_sentinel((node)->next) ? (ir_instruction
*) ((node)->next) : __null)) {
2709 ir_variable *const output_var = node->as_variable();
2710
2711 if (output_var == NULL__null || output_var->data.mode != ir_var_shader_out)
2712 continue;
2713
2714 /* Only geometry shaders can use non-zero streams */
2715 assert(output_var->data.stream == 0 ||(static_cast <bool> (output_var->data.stream == 0 ||
(output_var->data.stream < 4 && producer->Stage
== MESA_SHADER_GEOMETRY)) ? void (0) : __assert_fail ("output_var->data.stream == 0 || (output_var->data.stream < MAX_VERTEX_STREAMS && producer->Stage == MESA_SHADER_GEOMETRY)"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
))
2716 (output_var->data.stream < MAX_VERTEX_STREAMS &&(static_cast <bool> (output_var->data.stream == 0 ||
(output_var->data.stream < 4 && producer->Stage
== MESA_SHADER_GEOMETRY)) ? void (0) : __assert_fail ("output_var->data.stream == 0 || (output_var->data.stream < MAX_VERTEX_STREAMS && producer->Stage == MESA_SHADER_GEOMETRY)"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
))
2717 producer->Stage == MESA_SHADER_GEOMETRY))(static_cast <bool> (output_var->data.stream == 0 ||
(output_var->data.stream < 4 && producer->Stage
== MESA_SHADER_GEOMETRY)) ? void (0) : __assert_fail ("output_var->data.stream == 0 || (output_var->data.stream < MAX_VERTEX_STREAMS && producer->Stage == MESA_SHADER_GEOMETRY)"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
2718
2719 if (num_tfeedback_decls > 0) {
2720 tfeedback_candidate_generator g(mem_ctx, tfeedback_candidates, producer->Stage);
2721 /* From OpenGL 4.6 (Core Profile) spec, section 11.1.2.1
2722 * ("Vertex Shader Variables / Output Variables")
2723 *
2724 * "Each program object can specify a set of output variables from
2725 * one shader to be recorded in transform feedback mode (see
2726 * section 13.3). The variables that can be recorded are those
2727 * emitted by the first active shader, in order, from the
2728 * following list:
2729 *
2730 * * geometry shader
2731 * * tessellation evaluation shader
2732 * * tessellation control shader
2733 * * vertex shader"
2734 *
2735 * But on OpenGL ES 3.2, section 11.1.2.1 ("Vertex Shader
2736 * Variables / Output Variables") tessellation control shader is
2737 * not included in the stages list.
2738 */
2739 if (!prog->IsES || producer->Stage != MESA_SHADER_TESS_CTRL) {
2740 g.process(output_var);
2741 }
2742 }
2743
2744 ir_variable *const input_var =
2745 linker::get_matching_input(mem_ctx, output_var, consumer_inputs,
2746 consumer_interface_inputs,
2747 consumer_inputs_with_locations);
2748
2749 /* If a matching input variable was found, add this output (and the
2750 * input) to the set. If this is a separable program and there is no
2751 * consumer stage, add the output.
2752 *
2753 * Always add TCS outputs. They are shared by all invocations
2754 * within a patch and can be used as shared memory.
2755 */
2756 if (input_var || (prog->SeparateShader && consumer == NULL__null) ||
2757 producer->Stage == MESA_SHADER_TESS_CTRL) {
2758 matches.record(output_var, input_var);
2759 }
2760
2761 /* Only stream 0 outputs can be consumed in the next stage */
2762 if (input_var && output_var->data.stream != 0) {
2763 linker_error(prog, "output %s is assigned to stream=%d but "
2764 "is linked to an input, which requires stream=0",
2765 output_var->name, output_var->data.stream);
2766 ralloc_free(hash_table_ctx);
2767 return false;
2768 }
2769 }
2770 } else {
2771 /* If there's no producer stage, then this must be a separable program.
2772 * For example, we may have a program that has just a fragment shader.
2773 * Later this program will be used with some arbitrary vertex (or
2774 * geometry) shader program. This means that locations must be assigned
2775 * for all the inputs.
2776 */
2777 foreach_in_list(ir_instruction, node, consumer->ir)for (ir_instruction *node = (!exec_node_is_tail_sentinel((consumer
->ir)->head_sentinel.next) ? (ir_instruction *) ((consumer
->ir)->head_sentinel.next) : __null); (node) != __null;
(node) = (!exec_node_is_tail_sentinel((node)->next) ? (ir_instruction
*) ((node)->next) : __null)) {
11
←
Taking false branch
→
12
←
Access to field 'ir' results in a dereference of a null pointer (loaded from variable 'consumer')
2778 ir_variable *const input_var = node->as_variable();
2779 if (input_var && input_var->data.mode == ir_var_shader_in) {
2780 matches.record(NULL__null, input_var);
2781 }
2782 }
2783 }
2784
2785 for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
2786 if (!tfeedback_decls[i].is_varying())
2787 continue;
2788
2789 const tfeedback_candidate *matched_candidate
2790 = tfeedback_decls[i].find_candidate(prog, tfeedback_candidates);
2791
2792 if (matched_candidate == NULL__null) {
2793 ralloc_free(hash_table_ctx);
2794 return false;
2795 }
2796
2797 /* There are two situations where a new output varying is needed:
2798 *
2799 * - If varying packing is disabled for xfb and the current declaration
2800 * is not aligned within the top level varying (e.g. vec3_arr[1]).
2801 *
2802 * - If a builtin variable needs to be copied to a new variable
2803 * before its content is modified by another lowering pass (e.g.
2804 * \c gl_Position is transformed by \c nir_lower_viewport_transform).
2805 */
2806 const unsigned dmul =
2807 matched_candidate->type->without_array()->is_64bit() ? 2 : 1;
2808 const bool lowered =
2809 (disable_xfb_packing &&
2810 !tfeedback_decls[i].is_aligned(dmul, matched_candidate->offset)) ||
2811 (matched_candidate->toplevel_var->data.explicit_location &&
2812 matched_candidate->toplevel_var->data.location < VARYING_SLOT_VAR0 &&
2813 (ctx->Const.ShaderCompilerOptions[producer->Stage].LowerBuiltinVariablesXfb &
2814 BITFIELD_BIT(matched_candidate->toplevel_var->data.location)(1u << (matched_candidate->toplevel_var->data.location
))));
2815
2816 if (lowered) {
2817 ir_variable *new_var;
2818 tfeedback_candidate *new_candidate = NULL__null;
2819
2820 new_var = lower_xfb_varying(mem_ctx, producer, tfeedback_decls[i].name());
2821 if (new_var == NULL__null) {
2822 ralloc_free(hash_table_ctx);
2823 return false;
2824 }
2825
2826 /* Create new candidate and replace matched_candidate */
2827 new_candidate = rzalloc(mem_ctx, tfeedback_candidate)((tfeedback_candidate *) rzalloc_size(mem_ctx, sizeof(tfeedback_candidate
)));
2828 new_candidate->toplevel_var = new_var;
2829 new_candidate->toplevel_var->data.is_unmatched_generic_inout = 1;
2830 new_candidate->type = new_var->type;
2831 new_candidate->offset = 0;
2832 _mesa_hash_table_insert(tfeedback_candidates,
2833 ralloc_strdup(mem_ctx, new_var->name),
2834 new_candidate);
2835
2836 tfeedback_decls[i].set_lowered_candidate(new_candidate);
2837 matched_candidate = new_candidate;
2838 }
2839
2840 /* Mark as xfb varying */
2841 matched_candidate->toplevel_var->data.is_xfb = 1;
2842
2843 /* Mark xfb varyings as always active */
2844 matched_candidate->toplevel_var->data.always_active_io = 1;
2845
2846 /* Mark any corresponding inputs as always active also. We must do this
2847 * because we have a NIR pass that lowers vectors to scalars and another
2848 * that removes unused varyings.
2849 * We don't split varyings marked as always active because there is no
2850 * point in doing so. This means we need to mark both sides of the
2851 * interface as always active otherwise we will have a mismatch and
2852 * start removing things we shouldn't.
2853 */
2854 ir_variable *const input_var =
2855 linker::get_matching_input(mem_ctx, matched_candidate->toplevel_var,
2856 consumer_inputs,
2857 consumer_interface_inputs,
2858 consumer_inputs_with_locations);
2859 if (input_var) {
2860 input_var->data.is_xfb = 1;
2861 input_var->data.always_active_io = 1;
2862 }
2863
2864 if (matched_candidate->toplevel_var->data.is_unmatched_generic_inout) {
2865 matched_candidate->toplevel_var->data.is_xfb_only = 1;
2866 matches.record(matched_candidate->toplevel_var, NULL__null);
2867 }
2868 }
2869
2870 uint8_t components[MAX_VARYINGS_INCL_PATCH((((VARYING_SLOT_VAR0 + 32)) + 32) - VARYING_SLOT_VAR0)] = {0};
2871 const unsigned slots_used = matches.assign_locations(
2872 prog, components, reserved_slots);
2873 matches.store_locations();
2874
2875 for (unsigned i = 0; i < num_tfeedback_decls; ++i) {
2876 if (tfeedback_decls[i].is_varying()) {
2877 if (!tfeedback_decls[i].assign_location(ctx, prog)) {
2878 ralloc_free(hash_table_ctx);
2879 return false;
2880 }
2881 }
2882 }
2883 ralloc_free(hash_table_ctx);
2884
2885 if (consumer && producer) {
2886 foreach_in_list(ir_instruction, node, consumer->ir)for (ir_instruction *node = (!exec_node_is_tail_sentinel((consumer
->ir)->head_sentinel.next) ? (ir_instruction *) ((consumer
->ir)->head_sentinel.next) : __null); (node) != __null;
(node) = (!exec_node_is_tail_sentinel((node)->next) ? (ir_instruction
*) ((node)->next) : __null)) {
2887 ir_variable *const var = node->as_variable();
2888
2889 if (var && var->data.mode == ir_var_shader_in &&
2890 var->data.is_unmatched_generic_inout) {
2891 if (!prog->IsES && prog->data->Version <= 120) {
2892 /* On page 25 (page 31 of the PDF) of the GLSL 1.20 spec:
2893 *
2894 * Only those varying variables used (i.e. read) in
2895 * the fragment shader executable must be written to
2896 * by the vertex shader executable; declaring
2897 * superfluous varying variables in a vertex shader is
2898 * permissible.
2899 *
2900 * We interpret this text as meaning that the VS must
2901 * write the variable for the FS to read it. See
2902 * "glsl1-varying read but not written" in piglit.
2903 */
2904 linker_error(prog, "%s shader varying %s not written "
2905 "by %s shader\n.",
2906 _mesa_shader_stage_to_string(consumer->Stage),
2907 var->name,
2908 _mesa_shader_stage_to_string(producer->Stage));
2909 } else {
2910 linker_warning(prog, "%s shader varying %s not written "
2911 "by %s shader\n.",
2912 _mesa_shader_stage_to_string(consumer->Stage),
2913 var->name,
2914 _mesa_shader_stage_to_string(producer->Stage));
2915 }
2916 }
2917 }
2918
2919 /* Now that validation is done its safe to remove unused varyings. As
2920 * we have both a producer and consumer its safe to remove unused
2921 * varyings even if the program is a SSO because the stages are being
2922 * linked together i.e. we have a multi-stage SSO.
2923 */
2924 remove_unused_shader_inputs_and_outputs(false, producer,
2925 ir_var_shader_out);
2926 remove_unused_shader_inputs_and_outputs(false, consumer,
2927 ir_var_shader_in);
2928 }
2929
2930 if (producer) {
2931 lower_packed_varyings(mem_ctx, slots_used, components, ir_var_shader_out,
2932 0, producer, disable_varying_packing,
2933 disable_xfb_packing, xfb_enabled);
2934 }
2935
2936 if (consumer) {
2937 lower_packed_varyings(mem_ctx, slots_used, components, ir_var_shader_in,
2938 consumer_vertices, consumer, disable_varying_packing,
2939 disable_xfb_packing, xfb_enabled);
2940 }
2941
2942 return true;
2943}
2944
2945static bool
2946check_against_output_limit(struct gl_context *ctx,
2947 struct gl_shader_program *prog,
2948 gl_linked_shader *producer,
2949 unsigned num_explicit_locations)
2950{
2951 unsigned output_vectors = num_explicit_locations;
2952
2953 foreach_in_list(ir_instruction, node, producer->ir)for (ir_instruction *node = (!exec_node_is_tail_sentinel((producer
->ir)->head_sentinel.next) ? (ir_instruction *) ((producer
->ir)->head_sentinel.next) : __null); (node) != __null;
(node) = (!exec_node_is_tail_sentinel((node)->next) ? (ir_instruction
*) ((node)->next) : __null)) {
2954 ir_variable *const var = node->as_variable();
2955
2956 if (var && !var->data.explicit_location &&
2957 var->data.mode == ir_var_shader_out &&
2958 var_counts_against_varying_limit(producer->Stage, var)) {
2959 /* outputs for fragment shader can't be doubles */
2960 output_vectors += var->type->count_attribute_slots(false);
2961 }
2962 }
2963
2964 assert(producer->Stage != MESA_SHADER_FRAGMENT)(static_cast <bool> (producer->Stage != MESA_SHADER_FRAGMENT
) ? void (0) : __assert_fail ("producer->Stage != MESA_SHADER_FRAGMENT"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
2965 unsigned max_output_components =
2966 ctx->Const.Program[producer->Stage].MaxOutputComponents;
2967
2968 const unsigned output_components = output_vectors * 4;
2969 if (output_components > max_output_components) {
2970 if (ctx->API == API_OPENGLES2 || prog->IsES)
2971 linker_error(prog, "%s shader uses too many output vectors "
2972 "(%u > %u)\n",
2973 _mesa_shader_stage_to_string(producer->Stage),
2974 output_vectors,
2975 max_output_components / 4);
2976 else
2977 linker_error(prog, "%s shader uses too many output components "
2978 "(%u > %u)\n",
2979 _mesa_shader_stage_to_string(producer->Stage),
2980 output_components,
2981 max_output_components);
2982
2983 return false;
2984 }
2985
2986 return true;
2987}
2988
2989static bool
2990check_against_input_limit(struct gl_context *ctx,
2991 struct gl_shader_program *prog,
2992 gl_linked_shader *consumer,
2993 unsigned num_explicit_locations)
2994{
2995 unsigned input_vectors = num_explicit_locations;
2996
2997 foreach_in_list(ir_instruction, node, consumer->ir)for (ir_instruction *node = (!exec_node_is_tail_sentinel((consumer
->ir)->head_sentinel.next) ? (ir_instruction *) ((consumer
->ir)->head_sentinel.next) : __null); (node) != __null;
(node) = (!exec_node_is_tail_sentinel((node)->next) ? (ir_instruction
*) ((node)->next) : __null)) {
2998 ir_variable *const var = node->as_variable();
2999
3000 if (var && !var->data.explicit_location &&
3001 var->data.mode == ir_var_shader_in &&
3002 var_counts_against_varying_limit(consumer->Stage, var)) {
3003 /* vertex inputs aren't varying counted */
3004 input_vectors += var->type->count_attribute_slots(false);
3005 }
3006 }
3007
3008 assert(consumer->Stage != MESA_SHADER_VERTEX)(static_cast <bool> (consumer->Stage != MESA_SHADER_VERTEX
) ? void (0) : __assert_fail ("consumer->Stage != MESA_SHADER_VERTEX"
, __builtin_FILE (), __builtin_LINE (), __extension__ __PRETTY_FUNCTION__
));
3009 unsigned max_input_components =
3010 ctx->Const.Program[consumer->Stage].MaxInputComponents;
3011
3012 const unsigned input_components = input_vectors * 4;
3013 if (input_components > max_input_components) {
3014 if (ctx->API == API_OPENGLES2 || prog->IsES)
3015 linker_error(prog, "%s shader uses too many input vectors "
3016 "(%u > %u)\n",
3017 _mesa_shader_stage_to_string(consumer->Stage),
3018 input_vectors,
3019 max_input_components / 4);
3020 else
3021 linker_error(prog, "%s shader uses too many input components "
3022 "(%u > %u)\n",
3023 _mesa_shader_stage_to_string(consumer->Stage),
3024 input_components,
3025 max_input_components);
3026
3027 return false;
3028 }
3029
3030 return true;
3031}
3032
3033bool
3034link_varyings(struct gl_shader_program *prog, unsigned first, unsigned last,
3035 struct gl_context *ctx, void *mem_ctx)
3036{
3037 bool has_xfb_qualifiers = false;
3038 unsigned num_tfeedback_decls = 0;
3039 char **varying_names = NULL__null;
3040 tfeedback_decl *tfeedback_decls = NULL__null;
3041
3042 /* From the ARB_enhanced_layouts spec:
3043 *
3044 * "If the shader used to record output variables for transform feedback
3045 * varyings uses the "xfb_buffer", "xfb_offset", or "xfb_stride" layout
3046 * qualifiers, the values specified by TransformFeedbackVaryings are
3047 * ignored, and the set of variables captured for transform feedback is
3048 * instead derived from the specified layout qualifiers."
3049 */
3050 for (int i = MESA_SHADER_FRAGMENT - 1; i >= 0; i--) {
3051 /* Find last stage before fragment shader */
3052 if (prog->_LinkedShaders[i]) {
3053 has_xfb_qualifiers =
3054 process_xfb_layout_qualifiers(mem_ctx, prog->_LinkedShaders[i],
3055 prog, &num_tfeedback_decls,
3056 &varying_names);
3057 break;
3058 }
3059 }
3060
3061 if (!has_xfb_qualifiers) {
3062 num_tfeedback_decls = prog->TransformFeedback.NumVarying;
3063 varying_names = prog->TransformFeedback.VaryingNames;
3064 }
3065
3066 if (num_tfeedback_decls != 0) {
3067 /* From GL_EXT_transform_feedback:
3068 * A program will fail to link if:
3069 *
3070 * * the <count> specified by TransformFeedbackVaryingsEXT is
3071 * non-zero, but the program object has no vertex or geometry
3072 * shader;
3073 */
3074 if (first >= MESA_SHADER_FRAGMENT) {
3075 linker_error(prog, "Transform feedback varyings specified, but "
3076 "no vertex, tessellation, or geometry shader is "
3077 "present.\n");
3078 return false;
3079 }
3080
3081 tfeedback_decls = rzalloc_array(mem_ctx, tfeedback_decl,((tfeedback_decl *) rzalloc_array_size(mem_ctx, sizeof(tfeedback_decl
), num_tfeedback_decls))
3082 num_tfeedback_decls)((tfeedback_decl *) rzalloc_array_size(mem_ctx, sizeof(tfeedback_decl
), num_tfeedback_decls));
3083 if (!parse_tfeedback_decls(ctx, prog, mem_ctx, num_tfeedback_decls,
3084 varying_names, tfeedback_decls))
3085 return false;
3086 }
3087
3088 /* If there is no fragment shader we need to set transform feedback.
3089 *
3090 * For SSO we also need to assign output locations. We assign them here
3091 * because we need to do it for both single stage programs and multi stage
3092 * programs.
3093 */
3094 if (last < MESA_SHADER_FRAGMENT &&
3095 (num_tfeedback_decls != 0 || prog->SeparateShader)) {
3096 const uint64_t reserved_out_slots =
3097 reserved_varying_slot(prog->_LinkedShaders[last], ir_var_shader_out);
3098 if (!assign_varying_locations(ctx, mem_ctx, prog,
3099 prog->_LinkedShaders[last], NULL__null,
3100 num_tfeedback_decls, tfeedback_decls,
3101 reserved_out_slots))
3102 return false;
3103 }
3104
3105 if (last <= MESA_SHADER_FRAGMENT) {
3106 /* Remove unused varyings from the first/last stage unless SSO */
3107 remove_unused_shader_inputs_and_outputs(prog->SeparateShader,
3108 prog->_LinkedShaders[first],
3109 ir_var_shader_in);
3110 remove_unused_shader_inputs_and_outputs(prog->SeparateShader,
3111 prog->_LinkedShaders[last],
3112 ir_var_shader_out);
3113
3114 /* If the program is made up of only a single stage */
3115 if (first == last) {
3116 gl_linked_shader *const sh = prog->_LinkedShaders[last];
3117
3118 do_dead_builtin_varyings(ctx, NULL__null, sh, 0, NULL__null);
3119 do_dead_builtin_varyings(ctx, sh, NULL__null, num_tfeedback_decls,
3120 tfeedback_decls);
3121
3122 if (prog->SeparateShader) {
3123 const uint64_t reserved_slots =
3124 reserved_varying_slot(sh, ir_var_shader_in);
3125
3126 /* Assign input locations for SSO, output locations are already
3127 * assigned.
3128 */
3129 if (!assign_varying_locations(ctx, mem_ctx, prog,
3130 NULL__null /* producer */,
3131 sh /* consumer */,
3132 0 /* num_tfeedback_decls */,
3133 NULL__null /* tfeedback_decls */,
3134 reserved_slots))
3135 return false;
3136 }
3137 } else {
3138 /* Linking the stages in the opposite order (from fragment to vertex)
3139 * ensures that inter-shader outputs written to in an earlier stage
3140 * are eliminated if they are (transitively) not used in a later
3141 * stage.
3142 */
3143 int next = last;
3144 for (int i = next - 1; i >= 0; i--) {
3145 if (prog->_LinkedShaders[i] == NULL__null && i != 0)
3146 continue;
3147
3148 gl_linked_shader *const sh_i = prog->_LinkedShaders[i];
3149 gl_linked_shader *const sh_next = prog->_LinkedShaders[next];
3150
3151 const uint64_t reserved_out_slots =
3152 reserved_varying_slot(sh_i, ir_var_shader_out);
3153 const uint64_t reserved_in_slots =
3154 reserved_varying_slot(sh_next, ir_var_shader_in);
3155
3156 do_dead_builtin_varyings(ctx, sh_i, sh_next,
3157 next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0,
3158 tfeedback_decls);
3159
3160 if (!assign_varying_locations(ctx, mem_ctx, prog, sh_i, sh_next,
3161 next == MESA_SHADER_FRAGMENT ? num_tfeedback_decls : 0,
3162 tfeedback_decls,
3163 reserved_out_slots | reserved_in_slots))
3164 return false;
3165
3166 /* This must be done after all dead varyings are eliminated. */
3167 if (sh_i != NULL__null) {
3168 unsigned slots_used = util_bitcount64(reserved_out_slots);
3169 if (!check_against_output_limit(ctx, prog, sh_i, slots_used)) {
3170 return false;
3171 }
3172 }
3173
3174 unsigned slots_used = util_bitcount64(reserved_in_slots);
3175 if (!check_against_input_limit(ctx, prog, sh_next, slots_used))
3176 return false;
3177
3178 next = i;
3179 }
3180 }
3181 }
3182
3183 if (!store_tfeedback_info(ctx, prog, num_tfeedback_decls, tfeedback_decls,
3184 has_xfb_qualifiers, mem_ctx))
3185 return false;
3186
3187 return true;
3188}