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16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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21 * DEALINGS IN THE SOFTWARE.
25 * \file link_varyings.cpp
27 * Linker functions related specifically to linking varyings between shader
32 #include "main/mtypes.h"
33 #include "glsl_symbol_table.h"
34 #include "glsl_parser_extras.h"
35 #include "ir_optimization.h"
37 #include "link_varyings.h"
38 #include "main/macros.h"
39 #include "program/hash_table.h"
44 * Get the varying type stripped of the outermost array if we're processing
45 * a stage whose varyings are arrays indexed by a vertex number (such as
46 * geometry shader inputs).
48 static const glsl_type
*
49 get_varying_type(const ir_variable
*var
, gl_shader_stage stage
)
51 const glsl_type
*type
= var
->type
;
53 if (!var
->data
.patch
&&
54 ((var
->data
.mode
== ir_var_shader_out
&&
55 stage
== MESA_SHADER_TESS_CTRL
) ||
56 (var
->data
.mode
== ir_var_shader_in
&&
57 (stage
== MESA_SHADER_TESS_CTRL
|| stage
== MESA_SHADER_TESS_EVAL
||
58 stage
== MESA_SHADER_GEOMETRY
)))) {
59 assert(type
->is_array());
60 type
= type
->fields
.array
;
67 create_xfb_varying_names(void *mem_ctx
, const glsl_type
*t
, char **name
,
68 size_t name_length
, unsigned *count
,
69 const char *ifc_member_name
,
70 const glsl_type
*ifc_member_t
, char ***varying_names
)
72 if (t
->is_interface()) {
73 size_t new_length
= name_length
;
75 assert(ifc_member_name
&& ifc_member_t
);
76 ralloc_asprintf_rewrite_tail(name
, &new_length
, ".%s", ifc_member_name
);
78 create_xfb_varying_names(mem_ctx
, ifc_member_t
, name
, new_length
, count
,
79 NULL
, NULL
, varying_names
);
80 } else if (t
->is_record()) {
81 for (unsigned i
= 0; i
< t
->length
; i
++) {
82 const char *field
= t
->fields
.structure
[i
].name
;
83 size_t new_length
= name_length
;
85 ralloc_asprintf_rewrite_tail(name
, &new_length
, ".%s", field
);
87 create_xfb_varying_names(mem_ctx
, t
->fields
.structure
[i
].type
, name
,
88 new_length
, count
, NULL
, NULL
,
91 } else if (t
->without_array()->is_record() ||
92 t
->without_array()->is_interface() ||
93 (t
->is_array() && t
->fields
.array
->is_array())) {
94 for (unsigned i
= 0; i
< t
->length
; i
++) {
95 size_t new_length
= name_length
;
97 /* Append the subscript to the current variable name */
98 ralloc_asprintf_rewrite_tail(name
, &new_length
, "[%u]", i
);
100 create_xfb_varying_names(mem_ctx
, t
->fields
.array
, name
, new_length
,
101 count
, ifc_member_name
, ifc_member_t
,
105 (*varying_names
)[(*count
)++] = ralloc_strdup(mem_ctx
, *name
);
110 process_xfb_layout_qualifiers(void *mem_ctx
, const gl_linked_shader
*sh
,
111 unsigned *num_tfeedback_decls
,
112 char ***varying_names
)
114 bool has_xfb_qualifiers
= false;
116 /* We still need to enable transform feedback mode even if xfb_stride is
117 * only applied to a global out. Also we don't bother to propagate
118 * xfb_stride to interface block members so this will catch that case also.
120 for (unsigned j
= 0; j
< MAX_FEEDBACK_BUFFERS
; j
++) {
121 if (sh
->info
.TransformFeedback
.BufferStride
[j
]) {
122 has_xfb_qualifiers
= true;
126 foreach_in_list(ir_instruction
, node
, sh
->ir
) {
127 ir_variable
*var
= node
->as_variable();
128 if (!var
|| var
->data
.mode
!= ir_var_shader_out
)
131 /* From the ARB_enhanced_layouts spec:
133 * "Any shader making any static use (after preprocessing) of any of
134 * these *xfb_* qualifiers will cause the shader to be in a
135 * transform feedback capturing mode and hence responsible for
136 * describing the transform feedback setup. This mode will capture
137 * any output selected by *xfb_offset*, directly or indirectly, to
138 * a transform feedback buffer."
140 if (var
->data
.explicit_xfb_buffer
|| var
->data
.explicit_xfb_stride
) {
141 has_xfb_qualifiers
= true;
144 if (var
->data
.explicit_xfb_offset
) {
145 *num_tfeedback_decls
+= var
->type
->varying_count();
146 has_xfb_qualifiers
= true;
150 if (*num_tfeedback_decls
== 0)
151 return has_xfb_qualifiers
;
154 *varying_names
= ralloc_array(mem_ctx
, char *, *num_tfeedback_decls
);
155 foreach_in_list(ir_instruction
, node
, sh
->ir
) {
156 ir_variable
*var
= node
->as_variable();
157 if (!var
|| var
->data
.mode
!= ir_var_shader_out
)
160 if (var
->data
.explicit_xfb_offset
) {
162 const glsl_type
*type
, *member_type
;
164 if (var
->data
.from_named_ifc_block
) {
165 type
= var
->get_interface_type();
166 /* Find the member type before it was altered by lowering */
168 type
->fields
.structure
[type
->field_index(var
->name
)].type
;
169 name
= ralloc_strdup(NULL
, type
->without_array()->name
);
173 name
= ralloc_strdup(NULL
, var
->name
);
175 create_xfb_varying_names(mem_ctx
, type
, &name
, strlen(name
), &i
,
176 var
->name
, member_type
, varying_names
);
181 assert(i
== *num_tfeedback_decls
);
182 return has_xfb_qualifiers
;
186 anonymous_struct_type_matches(const glsl_type
*output_type
,
187 const glsl_type
*to_match
)
189 while (output_type
->is_array() && to_match
->is_array()) {
190 /* if the lengths at each level don't match fail. */
191 if (output_type
->length
!= to_match
->length
)
193 output_type
= output_type
->fields
.array
;
194 to_match
= to_match
->fields
.array
;
197 if (output_type
->is_array() || to_match
->is_array())
199 return output_type
->is_anonymous() &&
200 to_match
->is_anonymous() &&
201 to_match
->record_compare(output_type
);
205 * Validate the types and qualifiers of an output from one stage against the
206 * matching input to another stage.
209 cross_validate_types_and_qualifiers(struct gl_shader_program
*prog
,
210 const ir_variable
*input
,
211 const ir_variable
*output
,
212 gl_shader_stage consumer_stage
,
213 gl_shader_stage producer_stage
)
215 /* Check that the types match between stages.
217 const glsl_type
*type_to_match
= input
->type
;
219 /* VS -> GS, VS -> TCS, VS -> TES, TES -> GS */
220 const bool extra_array_level
= (producer_stage
== MESA_SHADER_VERTEX
&&
221 consumer_stage
!= MESA_SHADER_FRAGMENT
) ||
222 consumer_stage
== MESA_SHADER_GEOMETRY
;
223 if (extra_array_level
) {
224 assert(type_to_match
->is_array());
225 type_to_match
= type_to_match
->fields
.array
;
228 if (type_to_match
!= output
->type
) {
229 /* There is a bit of a special case for gl_TexCoord. This
230 * built-in is unsized by default. Applications that variable
231 * access it must redeclare it with a size. There is some
232 * language in the GLSL spec that implies the fragment shader
233 * and vertex shader do not have to agree on this size. Other
234 * driver behave this way, and one or two applications seem to
237 * Neither declaration needs to be modified here because the array
238 * sizes are fixed later when update_array_sizes is called.
240 * From page 48 (page 54 of the PDF) of the GLSL 1.10 spec:
242 * "Unlike user-defined varying variables, the built-in
243 * varying variables don't have a strict one-to-one
244 * correspondence between the vertex language and the
245 * fragment language."
247 if (!output
->type
->is_array() || !is_gl_identifier(output
->name
)) {
248 bool anon_matches
= anonymous_struct_type_matches(output
->type
, type_to_match
);
252 "%s shader output `%s' declared as type `%s', "
253 "but %s shader input declared as type `%s'\n",
254 _mesa_shader_stage_to_string(producer_stage
),
257 _mesa_shader_stage_to_string(consumer_stage
),
264 /* Check that all of the qualifiers match between stages.
267 /* According to the OpenGL and OpenGLES GLSL specs, the centroid qualifier
268 * should match until OpenGL 4.3 and OpenGLES 3.1. The OpenGLES 3.0
269 * conformance test suite does not verify that the qualifiers must match.
270 * The deqp test suite expects the opposite (OpenGLES 3.1) behavior for
271 * OpenGLES 3.0 drivers, so we relax the checking in all cases.
273 if (false /* always skip the centroid check */ &&
274 prog
->Version
< (prog
->IsES
? 310 : 430) &&
275 input
->data
.centroid
!= output
->data
.centroid
) {
277 "%s shader output `%s' %s centroid qualifier, "
278 "but %s shader input %s centroid qualifier\n",
279 _mesa_shader_stage_to_string(producer_stage
),
281 (output
->data
.centroid
) ? "has" : "lacks",
282 _mesa_shader_stage_to_string(consumer_stage
),
283 (input
->data
.centroid
) ? "has" : "lacks");
287 if (input
->data
.sample
!= output
->data
.sample
) {
289 "%s shader output `%s' %s sample qualifier, "
290 "but %s shader input %s sample qualifier\n",
291 _mesa_shader_stage_to_string(producer_stage
),
293 (output
->data
.sample
) ? "has" : "lacks",
294 _mesa_shader_stage_to_string(consumer_stage
),
295 (input
->data
.sample
) ? "has" : "lacks");
299 if (input
->data
.patch
!= output
->data
.patch
) {
301 "%s shader output `%s' %s patch qualifier, "
302 "but %s shader input %s patch qualifier\n",
303 _mesa_shader_stage_to_string(producer_stage
),
305 (output
->data
.patch
) ? "has" : "lacks",
306 _mesa_shader_stage_to_string(consumer_stage
),
307 (input
->data
.patch
) ? "has" : "lacks");
311 /* The GLSL 4.30 and GLSL ES 3.00 specifications say:
313 * "As only outputs need be declared with invariant, an output from
314 * one shader stage will still match an input of a subsequent stage
315 * without the input being declared as invariant."
317 * while GLSL 4.20 says:
319 * "For variables leaving one shader and coming into another shader,
320 * the invariant keyword has to be used in both shaders, or a link
321 * error will result."
323 * and GLSL ES 1.00 section 4.6.4 "Invariance and Linking" says:
325 * "The invariance of varyings that are declared in both the vertex
326 * and fragment shaders must match."
328 if (input
->data
.invariant
!= output
->data
.invariant
&&
329 prog
->Version
< (prog
->IsES
? 300 : 430)) {
331 "%s shader output `%s' %s invariant qualifier, "
332 "but %s shader input %s invariant qualifier\n",
333 _mesa_shader_stage_to_string(producer_stage
),
335 (output
->data
.invariant
) ? "has" : "lacks",
336 _mesa_shader_stage_to_string(consumer_stage
),
337 (input
->data
.invariant
) ? "has" : "lacks");
341 /* GLSL >= 4.40 removes text requiring interpolation qualifiers
342 * to match cross stage, they must only match within the same stage.
344 * From page 84 (page 90 of the PDF) of the GLSL 4.40 spec:
346 * "It is a link-time error if, within the same stage, the interpolation
347 * qualifiers of variables of the same name do not match.
350 if (input
->data
.interpolation
!= output
->data
.interpolation
&&
351 prog
->Version
< 440) {
353 "%s shader output `%s' specifies %s "
354 "interpolation qualifier, "
355 "but %s shader input specifies %s "
356 "interpolation qualifier\n",
357 _mesa_shader_stage_to_string(producer_stage
),
359 interpolation_string(output
->data
.interpolation
),
360 _mesa_shader_stage_to_string(consumer_stage
),
361 interpolation_string(input
->data
.interpolation
));
367 * Validate front and back color outputs against single color input
370 cross_validate_front_and_back_color(struct gl_shader_program
*prog
,
371 const ir_variable
*input
,
372 const ir_variable
*front_color
,
373 const ir_variable
*back_color
,
374 gl_shader_stage consumer_stage
,
375 gl_shader_stage producer_stage
)
377 if (front_color
!= NULL
&& front_color
->data
.assigned
)
378 cross_validate_types_and_qualifiers(prog
, input
, front_color
,
379 consumer_stage
, producer_stage
);
381 if (back_color
!= NULL
&& back_color
->data
.assigned
)
382 cross_validate_types_and_qualifiers(prog
, input
, back_color
,
383 consumer_stage
, producer_stage
);
387 * Validate that outputs from one stage match inputs of another
390 cross_validate_outputs_to_inputs(struct gl_shader_program
*prog
,
391 gl_linked_shader
*producer
,
392 gl_linked_shader
*consumer
)
394 glsl_symbol_table parameters
;
395 ir_variable
*explicit_locations
[MAX_VARYINGS_INCL_PATCH
][4] =
398 /* Find all shader outputs in the "producer" stage.
400 foreach_in_list(ir_instruction
, node
, producer
->ir
) {
401 ir_variable
*const var
= node
->as_variable();
403 if (var
== NULL
|| var
->data
.mode
!= ir_var_shader_out
)
406 if (!var
->data
.explicit_location
407 || var
->data
.location
< VARYING_SLOT_VAR0
)
408 parameters
.add_variable(var
);
410 /* User-defined varyings with explicit locations are handled
411 * differently because they do not need to have matching names.
413 const glsl_type
*type
= get_varying_type(var
, producer
->Stage
);
414 unsigned num_elements
= type
->count_attribute_slots(false);
415 unsigned idx
= var
->data
.location
- VARYING_SLOT_VAR0
;
416 unsigned slot_limit
= idx
+ num_elements
;
419 if (type
->without_array()->is_record()) {
420 /* The component qualifier can't be used on structs so just treat
421 * all component slots as used.
425 unsigned dmul
= type
->without_array()->is_64bit() ? 2 : 1;
426 last_comp
= var
->data
.location_frac
+
427 type
->without_array()->vector_elements
* dmul
;
430 while (idx
< slot_limit
) {
431 unsigned i
= var
->data
.location_frac
;
432 while (i
< last_comp
) {
433 if (explicit_locations
[idx
][i
] != NULL
) {
435 "%s shader has multiple outputs explicitly "
436 "assigned to location %d and component %d\n",
437 _mesa_shader_stage_to_string(producer
->Stage
),
438 idx
, var
->data
.location_frac
);
442 /* Make sure all component at this location have the same type.
444 for (unsigned j
= 0; j
< 4; j
++) {
445 if (explicit_locations
[idx
][j
] &&
446 (explicit_locations
[idx
][j
]->type
->without_array()
447 ->base_type
!= type
->without_array()->base_type
)) {
449 "Varyings sharing the same location must "
450 "have the same underlying numerical type. "
451 "Location %u component %u\n", idx
,
452 var
->data
.location_frac
);
457 explicit_locations
[idx
][i
] = var
;
460 /* We need to do some special handling for doubles as dvec3 and
461 * dvec4 consume two consecutive locations. We don't need to
462 * worry about components beginning at anything other than 0 as
463 * the spec does not allow this for dvec3 and dvec4.
465 if (i
== 4 && last_comp
> 4) {
466 last_comp
= last_comp
- 4;
467 /* Bump location index and reset the component index */
478 /* Find all shader inputs in the "consumer" stage. Any variables that have
479 * matching outputs already in the symbol table must have the same type and
482 * Exception: if the consumer is the geometry shader, then the inputs
483 * should be arrays and the type of the array element should match the type
484 * of the corresponding producer output.
486 foreach_in_list(ir_instruction
, node
, consumer
->ir
) {
487 ir_variable
*const input
= node
->as_variable();
489 if (input
== NULL
|| input
->data
.mode
!= ir_var_shader_in
)
492 if (strcmp(input
->name
, "gl_Color") == 0 && input
->data
.used
) {
493 const ir_variable
*const front_color
=
494 parameters
.get_variable("gl_FrontColor");
496 const ir_variable
*const back_color
=
497 parameters
.get_variable("gl_BackColor");
499 cross_validate_front_and_back_color(prog
, input
,
500 front_color
, back_color
,
501 consumer
->Stage
, producer
->Stage
);
502 } else if (strcmp(input
->name
, "gl_SecondaryColor") == 0 && input
->data
.used
) {
503 const ir_variable
*const front_color
=
504 parameters
.get_variable("gl_FrontSecondaryColor");
506 const ir_variable
*const back_color
=
507 parameters
.get_variable("gl_BackSecondaryColor");
509 cross_validate_front_and_back_color(prog
, input
,
510 front_color
, back_color
,
511 consumer
->Stage
, producer
->Stage
);
513 /* The rules for connecting inputs and outputs change in the presence
514 * of explicit locations. In this case, we no longer care about the
515 * names of the variables. Instead, we care only about the
516 * explicitly assigned location.
518 ir_variable
*output
= NULL
;
519 if (input
->data
.explicit_location
520 && input
->data
.location
>= VARYING_SLOT_VAR0
) {
522 const glsl_type
*type
= get_varying_type(input
, consumer
->Stage
);
523 unsigned num_elements
= type
->count_attribute_slots(false);
524 unsigned idx
= input
->data
.location
- VARYING_SLOT_VAR0
;
525 unsigned slot_limit
= idx
+ num_elements
;
527 while (idx
< slot_limit
) {
528 output
= explicit_locations
[idx
][input
->data
.location_frac
];
530 if (output
== NULL
||
531 input
->data
.location
!= output
->data
.location
) {
533 "%s shader input `%s' with explicit location "
534 "has no matching output\n",
535 _mesa_shader_stage_to_string(consumer
->Stage
),
542 output
= parameters
.get_variable(input
->name
);
545 if (output
!= NULL
) {
546 /* Interface blocks have their own validation elsewhere so don't
547 * try validating them here.
549 if (!(input
->get_interface_type() &&
550 output
->get_interface_type()))
551 cross_validate_types_and_qualifiers(prog
, input
, output
,
555 /* Check for input vars with unmatched output vars in prev stage
556 * taking into account that interface blocks could have a matching
557 * output but with different name, so we ignore them.
559 assert(!input
->data
.assigned
);
560 if (input
->data
.used
&& !input
->get_interface_type() &&
561 !input
->data
.explicit_location
&& !prog
->SeparateShader
)
563 "%s shader input `%s' "
564 "has no matching output in the previous stage\n",
565 _mesa_shader_stage_to_string(consumer
->Stage
),
573 * Demote shader inputs and outputs that are not used in other stages, and
574 * remove them via dead code elimination.
577 remove_unused_shader_inputs_and_outputs(bool is_separate_shader_object
,
578 gl_linked_shader
*sh
,
579 enum ir_variable_mode mode
)
581 if (is_separate_shader_object
)
584 foreach_in_list(ir_instruction
, node
, sh
->ir
) {
585 ir_variable
*const var
= node
->as_variable();
587 if (var
== NULL
|| var
->data
.mode
!= int(mode
))
590 /* A shader 'in' or 'out' variable is only really an input or output if
591 * its value is used by other shader stages. This will cause the
592 * variable to have a location assigned.
594 if (var
->data
.is_unmatched_generic_inout
&& !var
->data
.is_xfb_only
) {
595 assert(var
->data
.mode
!= ir_var_temporary
);
596 var
->data
.mode
= ir_var_auto
;
600 /* Eliminate code that is now dead due to unused inputs/outputs being
603 while (do_dead_code(sh
->ir
, false))
609 * Initialize this object based on a string that was passed to
610 * glTransformFeedbackVaryings.
612 * If the input is mal-formed, this call still succeeds, but it sets
613 * this->var_name to a mal-formed input, so tfeedback_decl::find_output_var()
614 * will fail to find any matching variable.
617 tfeedback_decl::init(struct gl_context
*ctx
, const void *mem_ctx
,
620 /* We don't have to be pedantic about what is a valid GLSL variable name,
621 * because any variable with an invalid name can't exist in the IR anyway.
625 this->orig_name
= input
;
626 this->lowered_builtin_array_variable
= none
;
627 this->skip_components
= 0;
628 this->next_buffer_separator
= false;
629 this->matched_candidate
= NULL
;
634 if (ctx
->Extensions
.ARB_transform_feedback3
) {
635 /* Parse gl_NextBuffer. */
636 if (strcmp(input
, "gl_NextBuffer") == 0) {
637 this->next_buffer_separator
= true;
641 /* Parse gl_SkipComponents. */
642 if (strcmp(input
, "gl_SkipComponents1") == 0)
643 this->skip_components
= 1;
644 else if (strcmp(input
, "gl_SkipComponents2") == 0)
645 this->skip_components
= 2;
646 else if (strcmp(input
, "gl_SkipComponents3") == 0)
647 this->skip_components
= 3;
648 else if (strcmp(input
, "gl_SkipComponents4") == 0)
649 this->skip_components
= 4;
651 if (this->skip_components
)
655 /* Parse a declaration. */
656 const char *base_name_end
;
657 long subscript
= parse_program_resource_name(input
, &base_name_end
);
658 this->var_name
= ralloc_strndup(mem_ctx
, input
, base_name_end
- input
);
659 if (this->var_name
== NULL
) {
660 _mesa_error_no_memory(__func__
);
664 if (subscript
>= 0) {
665 this->array_subscript
= subscript
;
666 this->is_subscripted
= true;
668 this->is_subscripted
= false;
671 /* For drivers that lower gl_ClipDistance to gl_ClipDistanceMESA, this
672 * class must behave specially to account for the fact that gl_ClipDistance
673 * is converted from a float[8] to a vec4[2].
675 if (ctx
->Const
.ShaderCompilerOptions
[MESA_SHADER_VERTEX
].LowerCombinedClipCullDistance
&&
676 strcmp(this->var_name
, "gl_ClipDistance") == 0) {
677 this->lowered_builtin_array_variable
= clip_distance
;
679 if (ctx
->Const
.ShaderCompilerOptions
[MESA_SHADER_VERTEX
].LowerCombinedClipCullDistance
&&
680 strcmp(this->var_name
, "gl_CullDistance") == 0) {
681 this->lowered_builtin_array_variable
= cull_distance
;
684 if (ctx
->Const
.LowerTessLevel
&&
685 (strcmp(this->var_name
, "gl_TessLevelOuter") == 0))
686 this->lowered_builtin_array_variable
= tess_level_outer
;
687 if (ctx
->Const
.LowerTessLevel
&&
688 (strcmp(this->var_name
, "gl_TessLevelInner") == 0))
689 this->lowered_builtin_array_variable
= tess_level_inner
;
694 * Determine whether two tfeedback_decl objects refer to the same variable and
695 * array index (if applicable).
698 tfeedback_decl::is_same(const tfeedback_decl
&x
, const tfeedback_decl
&y
)
700 assert(x
.is_varying() && y
.is_varying());
702 if (strcmp(x
.var_name
, y
.var_name
) != 0)
704 if (x
.is_subscripted
!= y
.is_subscripted
)
706 if (x
.is_subscripted
&& x
.array_subscript
!= y
.array_subscript
)
713 * Assign a location and stream ID for this tfeedback_decl object based on the
714 * transform feedback candidate found by find_candidate.
716 * If an error occurs, the error is reported through linker_error() and false
720 tfeedback_decl::assign_location(struct gl_context
*ctx
,
721 struct gl_shader_program
*prog
)
723 assert(this->is_varying());
725 unsigned fine_location
726 = this->matched_candidate
->toplevel_var
->data
.location
* 4
727 + this->matched_candidate
->toplevel_var
->data
.location_frac
728 + this->matched_candidate
->offset
;
729 const unsigned dmul
=
730 this->matched_candidate
->type
->without_array()->is_64bit() ? 2 : 1;
732 if (this->matched_candidate
->type
->is_array()) {
734 const unsigned matrix_cols
=
735 this->matched_candidate
->type
->fields
.array
->matrix_columns
;
736 const unsigned vector_elements
=
737 this->matched_candidate
->type
->fields
.array
->vector_elements
;
738 unsigned actual_array_size
;
739 switch (this->lowered_builtin_array_variable
) {
741 actual_array_size
= prog
->LastClipDistanceArraySize
;
744 actual_array_size
= prog
->LastCullDistanceArraySize
;
746 case tess_level_outer
:
747 actual_array_size
= 4;
749 case tess_level_inner
:
750 actual_array_size
= 2;
754 actual_array_size
= this->matched_candidate
->type
->array_size();
758 if (this->is_subscripted
) {
759 /* Check array bounds. */
760 if (this->array_subscript
>= actual_array_size
) {
761 linker_error(prog
, "Transform feedback varying %s has index "
762 "%i, but the array size is %u.",
763 this->orig_name
, this->array_subscript
,
767 unsigned array_elem_size
= this->lowered_builtin_array_variable
?
768 1 : vector_elements
* matrix_cols
* dmul
;
769 fine_location
+= array_elem_size
* this->array_subscript
;
772 this->size
= actual_array_size
;
774 this->vector_elements
= vector_elements
;
775 this->matrix_columns
= matrix_cols
;
776 if (this->lowered_builtin_array_variable
)
777 this->type
= GL_FLOAT
;
779 this->type
= this->matched_candidate
->type
->fields
.array
->gl_type
;
781 /* Regular variable (scalar, vector, or matrix) */
782 if (this->is_subscripted
) {
783 linker_error(prog
, "Transform feedback varying %s requested, "
784 "but %s is not an array.",
785 this->orig_name
, this->var_name
);
789 this->vector_elements
= this->matched_candidate
->type
->vector_elements
;
790 this->matrix_columns
= this->matched_candidate
->type
->matrix_columns
;
791 this->type
= this->matched_candidate
->type
->gl_type
;
793 this->location
= fine_location
/ 4;
794 this->location_frac
= fine_location
% 4;
796 /* From GL_EXT_transform_feedback:
797 * A program will fail to link if:
799 * * the total number of components to capture in any varying
800 * variable in <varyings> is greater than the constant
801 * MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS_EXT and the
802 * buffer mode is SEPARATE_ATTRIBS_EXT;
804 if (prog
->TransformFeedback
.BufferMode
== GL_SEPARATE_ATTRIBS
&&
805 this->num_components() >
806 ctx
->Const
.MaxTransformFeedbackSeparateComponents
) {
807 linker_error(prog
, "Transform feedback varying %s exceeds "
808 "MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS.",
813 /* Only transform feedback varyings can be assigned to non-zero streams,
814 * so assign the stream id here.
816 this->stream_id
= this->matched_candidate
->toplevel_var
->data
.stream
;
818 unsigned array_offset
= this->array_subscript
* 4 * dmul
;
819 unsigned struct_offset
= this->matched_candidate
->offset
* 4 * dmul
;
820 this->buffer
= this->matched_candidate
->toplevel_var
->data
.xfb_buffer
;
821 this->offset
= this->matched_candidate
->toplevel_var
->data
.offset
+
822 array_offset
+ struct_offset
;
829 tfeedback_decl::get_num_outputs() const
831 if (!this->is_varying()) {
834 return (this->num_components() + this->location_frac
+ 3)/4;
839 * Update gl_transform_feedback_info to reflect this tfeedback_decl.
841 * If an error occurs, the error is reported through linker_error() and false
845 tfeedback_decl::store(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
846 struct gl_transform_feedback_info
*info
,
847 unsigned buffer
, unsigned buffer_index
,
848 const unsigned max_outputs
, bool *explicit_stride
,
849 bool has_xfb_qualifiers
) const
851 unsigned xfb_offset
= 0;
852 unsigned size
= this->size
;
853 /* Handle gl_SkipComponents. */
854 if (this->skip_components
) {
855 info
->Buffers
[buffer
].Stride
+= this->skip_components
;
856 size
= this->skip_components
;
860 if (this->next_buffer_separator
) {
865 if (has_xfb_qualifiers
) {
866 xfb_offset
= this->offset
/ 4;
868 xfb_offset
= info
->Buffers
[buffer
].Stride
;
870 info
->Varyings
[info
->NumVarying
].Offset
= xfb_offset
* 4;
873 unsigned location
= this->location
;
874 unsigned location_frac
= this->location_frac
;
875 unsigned num_components
= this->num_components();
876 while (num_components
> 0) {
877 unsigned output_size
= MIN2(num_components
, 4 - location_frac
);
878 assert((info
->NumOutputs
== 0 && max_outputs
== 0) ||
879 info
->NumOutputs
< max_outputs
);
881 /* From the ARB_enhanced_layouts spec:
883 * "If such a block member or variable is not written during a shader
884 * invocation, the buffer contents at the assigned offset will be
885 * undefined. Even if there are no static writes to a variable or
886 * member that is assigned a transform feedback offset, the space is
887 * still allocated in the buffer and still affects the stride."
889 if (this->is_varying_written()) {
890 info
->Outputs
[info
->NumOutputs
].ComponentOffset
= location_frac
;
891 info
->Outputs
[info
->NumOutputs
].OutputRegister
= location
;
892 info
->Outputs
[info
->NumOutputs
].NumComponents
= output_size
;
893 info
->Outputs
[info
->NumOutputs
].StreamId
= stream_id
;
894 info
->Outputs
[info
->NumOutputs
].OutputBuffer
= buffer
;
895 info
->Outputs
[info
->NumOutputs
].DstOffset
= xfb_offset
;
898 info
->Buffers
[buffer
].Stream
= this->stream_id
;
899 xfb_offset
+= output_size
;
901 num_components
-= output_size
;
907 if (explicit_stride
&& explicit_stride
[buffer
]) {
908 if (this->is_64bit() && info
->Buffers
[buffer
].Stride
% 2) {
909 linker_error(prog
, "invalid qualifier xfb_stride=%d must be a "
910 "multiple of 8 as its applied to a type that is or "
911 "contains a double.",
912 info
->Buffers
[buffer
].Stride
* 4);
916 if ((this->offset
/ 4) / info
->Buffers
[buffer
].Stride
!=
917 (xfb_offset
- 1) / info
->Buffers
[buffer
].Stride
) {
918 linker_error(prog
, "xfb_offset (%d) overflows xfb_stride (%d) for "
919 "buffer (%d)", xfb_offset
* 4,
920 info
->Buffers
[buffer
].Stride
* 4, buffer
);
924 info
->Buffers
[buffer
].Stride
= xfb_offset
;
927 /* From GL_EXT_transform_feedback:
928 * A program will fail to link if:
930 * * the total number of components to capture is greater than
931 * the constant MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS_EXT
932 * and the buffer mode is INTERLEAVED_ATTRIBS_EXT.
934 * From GL_ARB_enhanced_layouts:
936 * "The resulting stride (implicit or explicit) must be less than or
937 * equal to the implementation-dependent constant
938 * gl_MaxTransformFeedbackInterleavedComponents."
940 if ((prog
->TransformFeedback
.BufferMode
== GL_INTERLEAVED_ATTRIBS
||
941 has_xfb_qualifiers
) &&
942 info
->Buffers
[buffer
].Stride
>
943 ctx
->Const
.MaxTransformFeedbackInterleavedComponents
) {
944 linker_error(prog
, "The MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS "
945 "limit has been exceeded.");
950 info
->Varyings
[info
->NumVarying
].Name
= ralloc_strdup(prog
,
952 info
->Varyings
[info
->NumVarying
].Type
= this->type
;
953 info
->Varyings
[info
->NumVarying
].Size
= size
;
954 info
->Varyings
[info
->NumVarying
].BufferIndex
= buffer_index
;
956 info
->Buffers
[buffer
].NumVaryings
++;
962 const tfeedback_candidate
*
963 tfeedback_decl::find_candidate(gl_shader_program
*prog
,
964 hash_table
*tfeedback_candidates
)
966 const char *name
= this->var_name
;
967 switch (this->lowered_builtin_array_variable
) {
969 name
= this->var_name
;
972 name
= "gl_ClipDistanceMESA";
975 name
= "gl_CullDistanceMESA";
977 case tess_level_outer
:
978 name
= "gl_TessLevelOuterMESA";
980 case tess_level_inner
:
981 name
= "gl_TessLevelInnerMESA";
984 this->matched_candidate
= (const tfeedback_candidate
*)
985 hash_table_find(tfeedback_candidates
, name
);
986 if (!this->matched_candidate
) {
987 /* From GL_EXT_transform_feedback:
988 * A program will fail to link if:
990 * * any variable name specified in the <varyings> array is not
991 * declared as an output in the geometry shader (if present) or
992 * the vertex shader (if no geometry shader is present);
994 linker_error(prog
, "Transform feedback varying %s undeclared.",
997 return this->matched_candidate
;
1002 * Parse all the transform feedback declarations that were passed to
1003 * glTransformFeedbackVaryings() and store them in tfeedback_decl objects.
1005 * If an error occurs, the error is reported through linker_error() and false
1009 parse_tfeedback_decls(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
1010 const void *mem_ctx
, unsigned num_names
,
1011 char **varying_names
, tfeedback_decl
*decls
)
1013 for (unsigned i
= 0; i
< num_names
; ++i
) {
1014 decls
[i
].init(ctx
, mem_ctx
, varying_names
[i
]);
1016 if (!decls
[i
].is_varying())
1019 /* From GL_EXT_transform_feedback:
1020 * A program will fail to link if:
1022 * * any two entries in the <varyings> array specify the same varying
1025 * We interpret this to mean "any two entries in the <varyings> array
1026 * specify the same varying variable and array index", since transform
1027 * feedback of arrays would be useless otherwise.
1029 for (unsigned j
= 0; j
< i
; ++j
) {
1030 if (!decls
[j
].is_varying())
1033 if (tfeedback_decl::is_same(decls
[i
], decls
[j
])) {
1034 linker_error(prog
, "Transform feedback varying %s specified "
1035 "more than once.", varying_names
[i
]);
1045 cmp_xfb_offset(const void * x_generic
, const void * y_generic
)
1047 tfeedback_decl
*x
= (tfeedback_decl
*) x_generic
;
1048 tfeedback_decl
*y
= (tfeedback_decl
*) y_generic
;
1050 if (x
->get_buffer() != y
->get_buffer())
1051 return x
->get_buffer() - y
->get_buffer();
1052 return x
->get_offset() - y
->get_offset();
1056 * Store transform feedback location assignments into
1057 * prog->LinkedTransformFeedback based on the data stored in tfeedback_decls.
1059 * If an error occurs, the error is reported through linker_error() and false
1063 store_tfeedback_info(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
1064 unsigned num_tfeedback_decls
,
1065 tfeedback_decl
*tfeedback_decls
, bool has_xfb_qualifiers
)
1067 /* Make sure MaxTransformFeedbackBuffers is less than 32 so the bitmask for
1068 * tracking the number of buffers doesn't overflow.
1070 assert(ctx
->Const
.MaxTransformFeedbackBuffers
< 32);
1072 bool separate_attribs_mode
=
1073 prog
->TransformFeedback
.BufferMode
== GL_SEPARATE_ATTRIBS
;
1075 ralloc_free(prog
->LinkedTransformFeedback
.Varyings
);
1076 ralloc_free(prog
->LinkedTransformFeedback
.Outputs
);
1078 memset(&prog
->LinkedTransformFeedback
, 0,
1079 sizeof(prog
->LinkedTransformFeedback
));
1081 /* The xfb_offset qualifier does not have to be used in increasing order
1082 * however some drivers expect to receive the list of transform feedback
1083 * declarations in order so sort it now for convenience.
1085 if (has_xfb_qualifiers
)
1086 qsort(tfeedback_decls
, num_tfeedback_decls
, sizeof(*tfeedback_decls
),
1089 prog
->LinkedTransformFeedback
.Varyings
=
1091 struct gl_transform_feedback_varying_info
,
1092 num_tfeedback_decls
);
1094 unsigned num_outputs
= 0;
1095 for (unsigned i
= 0; i
< num_tfeedback_decls
; ++i
) {
1096 if (tfeedback_decls
[i
].is_varying_written())
1097 num_outputs
+= tfeedback_decls
[i
].get_num_outputs();
1100 prog
->LinkedTransformFeedback
.Outputs
=
1102 struct gl_transform_feedback_output
,
1105 unsigned num_buffers
= 0;
1106 unsigned buffers
= 0;
1108 if (!has_xfb_qualifiers
&& separate_attribs_mode
) {
1109 /* GL_SEPARATE_ATTRIBS */
1110 for (unsigned i
= 0; i
< num_tfeedback_decls
; ++i
) {
1111 if (!tfeedback_decls
[i
].store(ctx
, prog
, &prog
->LinkedTransformFeedback
,
1112 num_buffers
, num_buffers
, num_outputs
,
1113 NULL
, has_xfb_qualifiers
))
1116 buffers
|= 1 << num_buffers
;
1121 /* GL_INVERLEAVED_ATTRIBS */
1122 int buffer_stream_id
= -1;
1124 num_tfeedback_decls
? tfeedback_decls
[0].get_buffer() : 0;
1125 bool explicit_stride
[MAX_FEEDBACK_BUFFERS
] = { false };
1127 /* Apply any xfb_stride global qualifiers */
1128 if (has_xfb_qualifiers
) {
1129 for (unsigned j
= 0; j
< MAX_FEEDBACK_BUFFERS
; j
++) {
1130 if (prog
->TransformFeedback
.BufferStride
[j
]) {
1132 explicit_stride
[j
] = true;
1133 prog
->LinkedTransformFeedback
.Buffers
[j
].Stride
=
1134 prog
->TransformFeedback
.BufferStride
[j
] / 4;
1139 for (unsigned i
= 0; i
< num_tfeedback_decls
; ++i
) {
1140 if (has_xfb_qualifiers
&&
1141 buffer
!= tfeedback_decls
[i
].get_buffer()) {
1142 /* we have moved to the next buffer so reset stream id */
1143 buffer_stream_id
= -1;
1147 if (tfeedback_decls
[i
].is_next_buffer_separator()) {
1148 if (!tfeedback_decls
[i
].store(ctx
, prog
,
1149 &prog
->LinkedTransformFeedback
,
1150 buffer
, num_buffers
, num_outputs
,
1151 explicit_stride
, has_xfb_qualifiers
))
1154 buffer_stream_id
= -1;
1156 } else if (tfeedback_decls
[i
].is_varying()) {
1157 if (buffer_stream_id
== -1) {
1158 /* First varying writing to this buffer: remember its stream */
1159 buffer_stream_id
= (int) tfeedback_decls
[i
].get_stream_id();
1160 } else if (buffer_stream_id
!=
1161 (int) tfeedback_decls
[i
].get_stream_id()) {
1162 /* Varying writes to the same buffer from a different stream */
1164 "Transform feedback can't capture varyings belonging "
1165 "to different vertex streams in a single buffer. "
1166 "Varying %s writes to buffer from stream %u, other "
1167 "varyings in the same buffer write from stream %u.",
1168 tfeedback_decls
[i
].name(),
1169 tfeedback_decls
[i
].get_stream_id(),
1175 if (has_xfb_qualifiers
) {
1176 buffer
= tfeedback_decls
[i
].get_buffer();
1178 buffer
= num_buffers
;
1180 buffers
|= 1 << buffer
;
1182 if (!tfeedback_decls
[i
].store(ctx
, prog
,
1183 &prog
->LinkedTransformFeedback
,
1184 buffer
, num_buffers
, num_outputs
,
1185 explicit_stride
, has_xfb_qualifiers
))
1190 assert(prog
->LinkedTransformFeedback
.NumOutputs
== num_outputs
);
1192 prog
->LinkedTransformFeedback
.ActiveBuffers
= buffers
;
1199 * Data structure recording the relationship between outputs of one shader
1200 * stage (the "producer") and inputs of another (the "consumer").
1202 class varying_matches
1205 varying_matches(bool disable_varying_packing
, bool xfb_enabled
,
1206 gl_shader_stage producer_stage
,
1207 gl_shader_stage consumer_stage
);
1209 void record(ir_variable
*producer_var
, ir_variable
*consumer_var
);
1210 unsigned assign_locations(struct gl_shader_program
*prog
,
1211 uint64_t reserved_slots
);
1212 void store_locations() const;
1215 bool is_varying_packing_safe(const glsl_type
*type
,
1216 const ir_variable
*var
);
1219 * If true, this driver disables varying packing, so all varyings need to
1220 * be aligned on slot boundaries, and take up a number of slots equal to
1221 * their number of matrix columns times their array size.
1223 * Packing may also be disabled because our current packing method is not
1224 * safe in SSO or versions of OpenGL where interpolation qualifiers are not
1225 * guaranteed to match across stages.
1227 const bool disable_varying_packing
;
1230 * If true, this driver has transform feedback enabled. The transform
1231 * feedback code requires at least some packing be done even when varying
1232 * packing is disabled, fortunately where transform feedback requires
1233 * packing it's safe to override the disabled setting. See
1234 * is_varying_packing_safe().
1236 const bool xfb_enabled
;
1239 * Enum representing the order in which varyings are packed within a
1242 * Currently we pack vec4's first, then vec2's, then scalar values, then
1243 * vec3's. This order ensures that the only vectors that are at risk of
1244 * having to be "double parked" (split between two adjacent varying slots)
1247 enum packing_order_enum
{
1250 PACKING_ORDER_SCALAR
,
1254 static unsigned compute_packing_class(const ir_variable
*var
);
1255 static packing_order_enum
compute_packing_order(const ir_variable
*var
);
1256 static int match_comparator(const void *x_generic
, const void *y_generic
);
1257 static int xfb_comparator(const void *x_generic
, const void *y_generic
);
1260 * Structure recording the relationship between a single producer output
1261 * and a single consumer input.
1265 * Packing class for this varying, computed by compute_packing_class().
1267 unsigned packing_class
;
1270 * Packing order for this varying, computed by compute_packing_order().
1272 packing_order_enum packing_order
;
1273 unsigned num_components
;
1276 * The output variable in the producer stage.
1278 ir_variable
*producer_var
;
1281 * The input variable in the consumer stage.
1283 ir_variable
*consumer_var
;
1286 * The location which has been assigned for this varying. This is
1287 * expressed in multiples of a float, with the first generic varying
1288 * (i.e. the one referred to by VARYING_SLOT_VAR0) represented by the
1291 unsigned generic_location
;
1295 * The number of elements in the \c matches array that are currently in
1298 unsigned num_matches
;
1301 * The number of elements that were set aside for the \c matches array when
1304 unsigned matches_capacity
;
1306 gl_shader_stage producer_stage
;
1307 gl_shader_stage consumer_stage
;
1310 } /* anonymous namespace */
1312 varying_matches::varying_matches(bool disable_varying_packing
,
1314 gl_shader_stage producer_stage
,
1315 gl_shader_stage consumer_stage
)
1316 : disable_varying_packing(disable_varying_packing
),
1317 xfb_enabled(xfb_enabled
),
1318 producer_stage(producer_stage
),
1319 consumer_stage(consumer_stage
)
1321 /* Note: this initial capacity is rather arbitrarily chosen to be large
1322 * enough for many cases without wasting an unreasonable amount of space.
1323 * varying_matches::record() will resize the array if there are more than
1324 * this number of varyings.
1326 this->matches_capacity
= 8;
1327 this->matches
= (match
*)
1328 malloc(sizeof(*this->matches
) * this->matches_capacity
);
1329 this->num_matches
= 0;
1333 varying_matches::~varying_matches()
1335 free(this->matches
);
1340 * Packing is always safe on individual arrays, structures, and matrices. It
1341 * is also safe if the varying is only used for transform feedback.
1344 varying_matches::is_varying_packing_safe(const glsl_type
*type
,
1345 const ir_variable
*var
)
1347 if (consumer_stage
== MESA_SHADER_TESS_EVAL
||
1348 consumer_stage
== MESA_SHADER_TESS_CTRL
||
1349 producer_stage
== MESA_SHADER_TESS_CTRL
)
1352 return xfb_enabled
&& (type
->is_array() || type
->is_record() ||
1353 type
->is_matrix() || var
->data
.is_xfb_only
);
1358 * Record the given producer/consumer variable pair in the list of variables
1359 * that should later be assigned locations.
1361 * It is permissible for \c consumer_var to be NULL (this happens if a
1362 * variable is output by the producer and consumed by transform feedback, but
1363 * not consumed by the consumer).
1365 * If \c producer_var has already been paired up with a consumer_var, or
1366 * producer_var is part of fixed pipeline functionality (and hence already has
1367 * a location assigned), this function has no effect.
1369 * Note: as a side effect this function may change the interpolation type of
1370 * \c producer_var, but only when the change couldn't possibly affect
1374 varying_matches::record(ir_variable
*producer_var
, ir_variable
*consumer_var
)
1376 assert(producer_var
!= NULL
|| consumer_var
!= NULL
);
1378 if ((producer_var
&& (!producer_var
->data
.is_unmatched_generic_inout
||
1379 producer_var
->data
.explicit_location
)) ||
1380 (consumer_var
&& (!consumer_var
->data
.is_unmatched_generic_inout
||
1381 consumer_var
->data
.explicit_location
))) {
1382 /* Either a location already exists for this variable (since it is part
1383 * of fixed functionality), or it has already been recorded as part of a
1389 bool needs_flat_qualifier
= consumer_var
== NULL
&&
1390 (producer_var
->type
->contains_integer() ||
1391 producer_var
->type
->contains_double());
1393 if (!disable_varying_packing
&&
1394 (needs_flat_qualifier
||
1395 (consumer_stage
!= -1 && consumer_stage
!= MESA_SHADER_FRAGMENT
))) {
1396 /* Since this varying is not being consumed by the fragment shader, its
1397 * interpolation type varying cannot possibly affect rendering.
1398 * Also, this variable is non-flat and is (or contains) an integer
1400 * If the consumer stage is unknown, don't modify the interpolation
1401 * type as it could affect rendering later with separate shaders.
1403 * lower_packed_varyings requires all integer varyings to flat,
1404 * regardless of where they appear. We can trivially satisfy that
1405 * requirement by changing the interpolation type to flat here.
1408 producer_var
->data
.centroid
= false;
1409 producer_var
->data
.sample
= false;
1410 producer_var
->data
.interpolation
= INTERP_MODE_FLAT
;
1414 consumer_var
->data
.centroid
= false;
1415 consumer_var
->data
.sample
= false;
1416 consumer_var
->data
.interpolation
= INTERP_MODE_FLAT
;
1420 if (this->num_matches
== this->matches_capacity
) {
1421 this->matches_capacity
*= 2;
1422 this->matches
= (match
*)
1423 realloc(this->matches
,
1424 sizeof(*this->matches
) * this->matches_capacity
);
1427 /* We must use the consumer to compute the packing class because in GL4.4+
1428 * there is no guarantee interpolation qualifiers will match across stages.
1430 * From Section 4.5 (Interpolation Qualifiers) of the GLSL 4.30 spec:
1432 * "The type and presence of interpolation qualifiers of variables with
1433 * the same name declared in all linked shaders for the same cross-stage
1434 * interface must match, otherwise the link command will fail.
1436 * When comparing an output from one stage to an input of a subsequent
1437 * stage, the input and output don't match if their interpolation
1438 * qualifiers (or lack thereof) are not the same."
1440 * This text was also in at least revison 7 of the 4.40 spec but is no
1441 * longer in revision 9 and not in the 4.50 spec.
1443 const ir_variable
*const var
= (consumer_var
!= NULL
)
1444 ? consumer_var
: producer_var
;
1445 const gl_shader_stage stage
= (consumer_var
!= NULL
)
1446 ? consumer_stage
: producer_stage
;
1447 const glsl_type
*type
= get_varying_type(var
, stage
);
1449 this->matches
[this->num_matches
].packing_class
1450 = this->compute_packing_class(var
);
1451 this->matches
[this->num_matches
].packing_order
1452 = this->compute_packing_order(var
);
1453 if (this->disable_varying_packing
&& !is_varying_packing_safe(type
, var
)) {
1454 unsigned slots
= type
->count_attribute_slots(false);
1455 this->matches
[this->num_matches
].num_components
= slots
* 4;
1457 this->matches
[this->num_matches
].num_components
1458 = type
->component_slots();
1460 this->matches
[this->num_matches
].producer_var
= producer_var
;
1461 this->matches
[this->num_matches
].consumer_var
= consumer_var
;
1462 this->num_matches
++;
1464 producer_var
->data
.is_unmatched_generic_inout
= 0;
1466 consumer_var
->data
.is_unmatched_generic_inout
= 0;
1471 * Choose locations for all of the variable matches that were previously
1472 * passed to varying_matches::record().
1475 varying_matches::assign_locations(struct gl_shader_program
*prog
,
1476 uint64_t reserved_slots
)
1478 /* If packing has been disabled then we cannot safely sort the varyings by
1479 * class as it may mean we are using a version of OpenGL where
1480 * interpolation qualifiers are not guaranteed to be matching across
1481 * shaders, sorting in this case could result in mismatching shader
1483 * When packing is disabled the sort orders varyings used by transform
1484 * feedback first, but also depends on *undefined behaviour* of qsort to
1485 * reverse the order of the varyings. See: xfb_comparator().
1487 if (!this->disable_varying_packing
) {
1488 /* Sort varying matches into an order that makes them easy to pack. */
1489 qsort(this->matches
, this->num_matches
, sizeof(*this->matches
),
1490 &varying_matches::match_comparator
);
1492 /* Only sort varyings that are only used by transform feedback. */
1493 qsort(this->matches
, this->num_matches
, sizeof(*this->matches
),
1494 &varying_matches::xfb_comparator
);
1497 unsigned generic_location
= 0;
1498 unsigned generic_patch_location
= MAX_VARYING
*4;
1499 bool previous_var_xfb_only
= false;
1501 for (unsigned i
= 0; i
< this->num_matches
; i
++) {
1502 unsigned *location
= &generic_location
;
1504 const ir_variable
*var
;
1505 const glsl_type
*type
;
1506 bool is_vertex_input
= false;
1507 if (matches
[i
].consumer_var
) {
1508 var
= matches
[i
].consumer_var
;
1509 type
= get_varying_type(var
, consumer_stage
);
1510 if (consumer_stage
== MESA_SHADER_VERTEX
)
1511 is_vertex_input
= true;
1513 var
= matches
[i
].producer_var
;
1514 type
= get_varying_type(var
, producer_stage
);
1517 if (var
->data
.patch
)
1518 location
= &generic_patch_location
;
1520 /* Advance to the next slot if this varying has a different packing
1521 * class than the previous one, and we're not already on a slot
1524 * Also advance to the next slot if packing is disabled. This makes sure
1525 * we don't assign varyings the same locations which is possible
1526 * because we still pack individual arrays, records and matrices even
1527 * when packing is disabled. Note we don't advance to the next slot if
1528 * we can pack varyings together that are only used for transform
1531 if ((this->disable_varying_packing
&&
1532 !(previous_var_xfb_only
&& var
->data
.is_xfb_only
)) ||
1533 (i
> 0 && this->matches
[i
- 1].packing_class
1534 != this->matches
[i
].packing_class
)) {
1535 *location
= ALIGN(*location
, 4);
1538 previous_var_xfb_only
= var
->data
.is_xfb_only
;
1540 unsigned num_elements
= type
->count_attribute_slots(is_vertex_input
);
1542 if (this->disable_varying_packing
&&
1543 !is_varying_packing_safe(type
, var
))
1546 slot_end
= type
->without_array()->vector_elements
;
1547 slot_end
+= *location
- 1;
1549 /* FIXME: We could be smarter in the below code and loop back over
1550 * trying to fill any locations that we skipped because we couldn't pack
1551 * the varying between an explicit location. For now just let the user
1552 * hit the linking error if we run out of room and suggest they use
1553 * explicit locations.
1555 for (unsigned j
= 0; j
< num_elements
; j
++) {
1556 while ((slot_end
< MAX_VARYING
* 4u) &&
1557 ((reserved_slots
& (UINT64_C(1) << *location
/ 4u) ||
1558 (reserved_slots
& (UINT64_C(1) << slot_end
/ 4u))))) {
1560 *location
= ALIGN(*location
+ 1, 4);
1561 slot_end
= *location
;
1563 /* reset the counter and try again */
1567 /* Increase the slot to make sure there is enough room for next
1570 if (this->disable_varying_packing
&&
1571 !is_varying_packing_safe(type
, var
))
1574 slot_end
+= type
->without_array()->vector_elements
;
1577 if (!var
->data
.patch
&& *location
>= MAX_VARYING
* 4u) {
1578 linker_error(prog
, "insufficient contiguous locations available for "
1579 "%s it is possible an array or struct could not be "
1580 "packed between varyings with explicit locations. Try "
1581 "using an explicit location for arrays and structs.",
1585 this->matches
[i
].generic_location
= *location
;
1587 *location
+= this->matches
[i
].num_components
;
1590 return (generic_location
+ 3) / 4;
1595 * Update the producer and consumer shaders to reflect the locations
1596 * assignments that were made by varying_matches::assign_locations().
1599 varying_matches::store_locations() const
1601 for (unsigned i
= 0; i
< this->num_matches
; i
++) {
1602 ir_variable
*producer_var
= this->matches
[i
].producer_var
;
1603 ir_variable
*consumer_var
= this->matches
[i
].consumer_var
;
1604 unsigned generic_location
= this->matches
[i
].generic_location
;
1605 unsigned slot
= generic_location
/ 4;
1606 unsigned offset
= generic_location
% 4;
1609 producer_var
->data
.location
= VARYING_SLOT_VAR0
+ slot
;
1610 producer_var
->data
.location_frac
= offset
;
1614 assert(consumer_var
->data
.location
== -1);
1615 consumer_var
->data
.location
= VARYING_SLOT_VAR0
+ slot
;
1616 consumer_var
->data
.location_frac
= offset
;
1623 * Compute the "packing class" of the given varying. This is an unsigned
1624 * integer with the property that two variables in the same packing class can
1625 * be safely backed into the same vec4.
1628 varying_matches::compute_packing_class(const ir_variable
*var
)
1630 /* Without help from the back-end, there is no way to pack together
1631 * variables with different interpolation types, because
1632 * lower_packed_varyings must choose exactly one interpolation type for
1633 * each packed varying it creates.
1635 * However, we can safely pack together floats, ints, and uints, because:
1637 * - varyings of base type "int" and "uint" must use the "flat"
1638 * interpolation type, which can only occur in GLSL 1.30 and above.
1640 * - On platforms that support GLSL 1.30 and above, lower_packed_varyings
1641 * can store flat floats as ints without losing any information (using
1642 * the ir_unop_bitcast_* opcodes).
1644 * Therefore, the packing class depends only on the interpolation type.
1646 unsigned packing_class
= var
->data
.centroid
| (var
->data
.sample
<< 1) |
1647 (var
->data
.patch
<< 2);
1649 packing_class
+= var
->is_interpolation_flat()
1650 ? unsigned(INTERP_MODE_FLAT
) : var
->data
.interpolation
;
1651 return packing_class
;
1656 * Compute the "packing order" of the given varying. This is a sort key we
1657 * use to determine when to attempt to pack the given varying relative to
1658 * other varyings in the same packing class.
1660 varying_matches::packing_order_enum
1661 varying_matches::compute_packing_order(const ir_variable
*var
)
1663 const glsl_type
*element_type
= var
->type
;
1665 while (element_type
->base_type
== GLSL_TYPE_ARRAY
) {
1666 element_type
= element_type
->fields
.array
;
1669 switch (element_type
->component_slots() % 4) {
1670 case 1: return PACKING_ORDER_SCALAR
;
1671 case 2: return PACKING_ORDER_VEC2
;
1672 case 3: return PACKING_ORDER_VEC3
;
1673 case 0: return PACKING_ORDER_VEC4
;
1675 assert(!"Unexpected value of vector_elements");
1676 return PACKING_ORDER_VEC4
;
1682 * Comparison function passed to qsort() to sort varyings by packing_class and
1683 * then by packing_order.
1686 varying_matches::match_comparator(const void *x_generic
, const void *y_generic
)
1688 const match
*x
= (const match
*) x_generic
;
1689 const match
*y
= (const match
*) y_generic
;
1691 if (x
->packing_class
!= y
->packing_class
)
1692 return x
->packing_class
- y
->packing_class
;
1693 return x
->packing_order
- y
->packing_order
;
1698 * Comparison function passed to qsort() to sort varyings used only by
1699 * transform feedback when packing of other varyings is disabled.
1702 varying_matches::xfb_comparator(const void *x_generic
, const void *y_generic
)
1704 const match
*x
= (const match
*) x_generic
;
1706 if (x
->producer_var
!= NULL
&& x
->producer_var
->data
.is_xfb_only
)
1707 return match_comparator(x_generic
, y_generic
);
1709 /* FIXME: When the comparator returns 0 it means the elements being
1710 * compared are equivalent. However the qsort documentation says:
1712 * "The order of equivalent elements is undefined."
1714 * In practice the sort ends up reversing the order of the varyings which
1715 * means locations are also assigned in this reversed order and happens to
1716 * be what we want. This is also whats happening in
1717 * varying_matches::match_comparator().
1724 * Is the given variable a varying variable to be counted against the
1725 * limit in ctx->Const.MaxVarying?
1726 * This includes variables such as texcoords, colors and generic
1727 * varyings, but excludes variables such as gl_FrontFacing and gl_FragCoord.
1730 var_counts_against_varying_limit(gl_shader_stage stage
, const ir_variable
*var
)
1732 /* Only fragment shaders will take a varying variable as an input */
1733 if (stage
== MESA_SHADER_FRAGMENT
&&
1734 var
->data
.mode
== ir_var_shader_in
) {
1735 switch (var
->data
.location
) {
1736 case VARYING_SLOT_POS
:
1737 case VARYING_SLOT_FACE
:
1738 case VARYING_SLOT_PNTC
:
1749 * Visitor class that generates tfeedback_candidate structs describing all
1750 * possible targets of transform feedback.
1752 * tfeedback_candidate structs are stored in the hash table
1753 * tfeedback_candidates, which is passed to the constructor. This hash table
1754 * maps varying names to instances of the tfeedback_candidate struct.
1756 class tfeedback_candidate_generator
: public program_resource_visitor
1759 tfeedback_candidate_generator(void *mem_ctx
,
1760 hash_table
*tfeedback_candidates
)
1762 tfeedback_candidates(tfeedback_candidates
),
1768 void process(ir_variable
*var
)
1770 /* All named varying interface blocks should be flattened by now */
1771 assert(!var
->is_interface_instance());
1773 this->toplevel_var
= var
;
1774 this->varying_floats
= 0;
1775 program_resource_visitor::process(var
);
1779 virtual void visit_field(const glsl_type
*type
, const char *name
,
1782 assert(!type
->without_array()->is_record());
1783 assert(!type
->without_array()->is_interface());
1787 tfeedback_candidate
*candidate
1788 = rzalloc(this->mem_ctx
, tfeedback_candidate
);
1789 candidate
->toplevel_var
= this->toplevel_var
;
1790 candidate
->type
= type
;
1791 candidate
->offset
= this->varying_floats
;
1792 hash_table_insert(this->tfeedback_candidates
, candidate
,
1793 ralloc_strdup(this->mem_ctx
, name
));
1794 this->varying_floats
+= type
->component_slots();
1798 * Memory context used to allocate hash table keys and values.
1800 void * const mem_ctx
;
1803 * Hash table in which tfeedback_candidate objects should be stored.
1805 hash_table
* const tfeedback_candidates
;
1808 * Pointer to the toplevel variable that is being traversed.
1810 ir_variable
*toplevel_var
;
1813 * Total number of varying floats that have been visited so far. This is
1814 * used to determine the offset to each varying within the toplevel
1817 unsigned varying_floats
;
1824 populate_consumer_input_sets(void *mem_ctx
, exec_list
*ir
,
1825 hash_table
*consumer_inputs
,
1826 hash_table
*consumer_interface_inputs
,
1827 ir_variable
*consumer_inputs_with_locations
[VARYING_SLOT_TESS_MAX
])
1829 memset(consumer_inputs_with_locations
,
1831 sizeof(consumer_inputs_with_locations
[0]) * VARYING_SLOT_TESS_MAX
);
1833 foreach_in_list(ir_instruction
, node
, ir
) {
1834 ir_variable
*const input_var
= node
->as_variable();
1836 if (input_var
!= NULL
&& input_var
->data
.mode
== ir_var_shader_in
) {
1837 /* All interface blocks should have been lowered by this point */
1838 assert(!input_var
->type
->is_interface());
1840 if (input_var
->data
.explicit_location
) {
1841 /* assign_varying_locations only cares about finding the
1842 * ir_variable at the start of a contiguous location block.
1844 * - For !producer, consumer_inputs_with_locations isn't used.
1846 * - For !consumer, consumer_inputs_with_locations is empty.
1848 * For consumer && producer, if you were trying to set some
1849 * ir_variable to the middle of a location block on the other side
1850 * of producer/consumer, cross_validate_outputs_to_inputs() should
1851 * be link-erroring due to either type mismatch or location
1852 * overlaps. If the variables do match up, then they've got a
1853 * matching data.location and you only looked at
1854 * consumer_inputs_with_locations[var->data.location], not any
1855 * following entries for the array/structure.
1857 consumer_inputs_with_locations
[input_var
->data
.location
] =
1859 } else if (input_var
->get_interface_type() != NULL
) {
1860 char *const iface_field_name
=
1861 ralloc_asprintf(mem_ctx
, "%s.%s",
1862 input_var
->get_interface_type()->without_array()->name
,
1864 hash_table_insert(consumer_interface_inputs
, input_var
,
1867 hash_table_insert(consumer_inputs
, input_var
,
1868 ralloc_strdup(mem_ctx
, input_var
->name
));
1875 * Find a variable from the consumer that "matches" the specified variable
1877 * This function only finds inputs with names that match. There is no
1878 * validation (here) that the types, etc. are compatible.
1881 get_matching_input(void *mem_ctx
,
1882 const ir_variable
*output_var
,
1883 hash_table
*consumer_inputs
,
1884 hash_table
*consumer_interface_inputs
,
1885 ir_variable
*consumer_inputs_with_locations
[VARYING_SLOT_TESS_MAX
])
1887 ir_variable
*input_var
;
1889 if (output_var
->data
.explicit_location
) {
1890 input_var
= consumer_inputs_with_locations
[output_var
->data
.location
];
1891 } else if (output_var
->get_interface_type() != NULL
) {
1892 char *const iface_field_name
=
1893 ralloc_asprintf(mem_ctx
, "%s.%s",
1894 output_var
->get_interface_type()->without_array()->name
,
1897 (ir_variable
*) hash_table_find(consumer_interface_inputs
,
1901 (ir_variable
*) hash_table_find(consumer_inputs
, output_var
->name
);
1904 return (input_var
== NULL
|| input_var
->data
.mode
!= ir_var_shader_in
)
1911 io_variable_cmp(const void *_a
, const void *_b
)
1913 const ir_variable
*const a
= *(const ir_variable
**) _a
;
1914 const ir_variable
*const b
= *(const ir_variable
**) _b
;
1916 if (a
->data
.explicit_location
&& b
->data
.explicit_location
)
1917 return b
->data
.location
- a
->data
.location
;
1919 if (a
->data
.explicit_location
&& !b
->data
.explicit_location
)
1922 if (!a
->data
.explicit_location
&& b
->data
.explicit_location
)
1925 return -strcmp(a
->name
, b
->name
);
1929 * Sort the shader IO variables into canonical order
1932 canonicalize_shader_io(exec_list
*ir
, enum ir_variable_mode io_mode
)
1934 ir_variable
*var_table
[MAX_PROGRAM_OUTPUTS
* 4];
1935 unsigned num_variables
= 0;
1937 foreach_in_list(ir_instruction
, node
, ir
) {
1938 ir_variable
*const var
= node
->as_variable();
1940 if (var
== NULL
|| var
->data
.mode
!= io_mode
)
1943 /* If we have already encountered more I/O variables that could
1944 * successfully link, bail.
1946 if (num_variables
== ARRAY_SIZE(var_table
))
1949 var_table
[num_variables
++] = var
;
1952 if (num_variables
== 0)
1955 /* Sort the list in reverse order (io_variable_cmp handles this). Later
1956 * we're going to push the variables on to the IR list as a stack, so we
1957 * want the last variable (in canonical order) to be first in the list.
1959 qsort(var_table
, num_variables
, sizeof(var_table
[0]), io_variable_cmp
);
1961 /* Remove the variable from it's current location in the IR, and put it at
1964 for (unsigned i
= 0; i
< num_variables
; i
++) {
1965 var_table
[i
]->remove();
1966 ir
->push_head(var_table
[i
]);
1971 * Generate a bitfield map of the explicit locations for shader varyings.
1973 * Note: For Tessellation shaders we are sitting right on the limits of the
1974 * 64 bit map. Per-vertex and per-patch both have separate location domains
1975 * with a max of MAX_VARYING.
1978 reserved_varying_slot(struct gl_linked_shader
*stage
,
1979 ir_variable_mode io_mode
)
1981 assert(io_mode
== ir_var_shader_in
|| io_mode
== ir_var_shader_out
);
1982 /* Avoid an overflow of the returned value */
1983 assert(MAX_VARYINGS_INCL_PATCH
<= 64);
1991 foreach_in_list(ir_instruction
, node
, stage
->ir
) {
1992 ir_variable
*const var
= node
->as_variable();
1994 if (var
== NULL
|| var
->data
.mode
!= io_mode
||
1995 !var
->data
.explicit_location
||
1996 var
->data
.location
< VARYING_SLOT_VAR0
)
1999 var_slot
= var
->data
.location
- VARYING_SLOT_VAR0
;
2001 unsigned num_elements
= get_varying_type(var
, stage
->Stage
)
2002 ->count_attribute_slots(stage
->Stage
== MESA_SHADER_VERTEX
);
2003 for (unsigned i
= 0; i
< num_elements
; i
++) {
2004 if (var_slot
>= 0 && var_slot
< MAX_VARYINGS_INCL_PATCH
)
2005 slots
|= UINT64_C(1) << var_slot
;
2015 * Assign locations for all variables that are produced in one pipeline stage
2016 * (the "producer") and consumed in the next stage (the "consumer").
2018 * Variables produced by the producer may also be consumed by transform
2021 * \param num_tfeedback_decls is the number of declarations indicating
2022 * variables that may be consumed by transform feedback.
2024 * \param tfeedback_decls is a pointer to an array of tfeedback_decl objects
2025 * representing the result of parsing the strings passed to
2026 * glTransformFeedbackVaryings(). assign_location() will be called for
2027 * each of these objects that matches one of the outputs of the
2030 * When num_tfeedback_decls is nonzero, it is permissible for the consumer to
2031 * be NULL. In this case, varying locations are assigned solely based on the
2032 * requirements of transform feedback.
2035 assign_varying_locations(struct gl_context
*ctx
,
2037 struct gl_shader_program
*prog
,
2038 gl_linked_shader
*producer
,
2039 gl_linked_shader
*consumer
,
2040 unsigned num_tfeedback_decls
,
2041 tfeedback_decl
*tfeedback_decls
,
2042 const uint64_t reserved_slots
)
2044 /* Tessellation shaders treat inputs and outputs as shared memory and can
2045 * access inputs and outputs of other invocations.
2046 * Therefore, they can't be lowered to temps easily (and definitely not
2049 bool unpackable_tess
=
2050 (consumer
&& consumer
->Stage
== MESA_SHADER_TESS_EVAL
) ||
2051 (consumer
&& consumer
->Stage
== MESA_SHADER_TESS_CTRL
) ||
2052 (producer
&& producer
->Stage
== MESA_SHADER_TESS_CTRL
);
2054 /* Transform feedback code assumes varying arrays are packed, so if the
2055 * driver has disabled varying packing, make sure to at least enable
2056 * packing required by transform feedback.
2059 ctx
->Extensions
.EXT_transform_feedback
&& !unpackable_tess
;
2061 /* Disable packing on outward facing interfaces for SSO because in ES we
2062 * need to retain the unpacked varying information for draw time
2065 * Packing is still enabled on individual arrays, structs, and matrices as
2066 * these are required by the transform feedback code and it is still safe
2067 * to do so. We also enable packing when a varying is only used for
2068 * transform feedback and its not a SSO.
2070 bool disable_varying_packing
=
2071 ctx
->Const
.DisableVaryingPacking
|| unpackable_tess
;
2072 if (prog
->SeparateShader
&& (producer
== NULL
|| consumer
== NULL
))
2073 disable_varying_packing
= true;
2075 varying_matches
matches(disable_varying_packing
, xfb_enabled
,
2076 producer
? producer
->Stage
: (gl_shader_stage
)-1,
2077 consumer
? consumer
->Stage
: (gl_shader_stage
)-1);
2078 hash_table
*tfeedback_candidates
2079 = hash_table_ctor(0, hash_table_string_hash
, hash_table_string_compare
);
2080 hash_table
*consumer_inputs
2081 = hash_table_ctor(0, hash_table_string_hash
, hash_table_string_compare
);
2082 hash_table
*consumer_interface_inputs
2083 = hash_table_ctor(0, hash_table_string_hash
, hash_table_string_compare
);
2084 ir_variable
*consumer_inputs_with_locations
[VARYING_SLOT_TESS_MAX
] = {
2088 unsigned consumer_vertices
= 0;
2089 if (consumer
&& consumer
->Stage
== MESA_SHADER_GEOMETRY
)
2090 consumer_vertices
= prog
->Geom
.VerticesIn
;
2092 /* Operate in a total of four passes.
2094 * 1. Sort inputs / outputs into a canonical order. This is necessary so
2095 * that inputs / outputs of separable shaders will be assigned
2096 * predictable locations regardless of the order in which declarations
2097 * appeared in the shader source.
2099 * 2. Assign locations for any matching inputs and outputs.
2101 * 3. Mark output variables in the producer that do not have locations as
2102 * not being outputs. This lets the optimizer eliminate them.
2104 * 4. Mark input variables in the consumer that do not have locations as
2105 * not being inputs. This lets the optimizer eliminate them.
2108 canonicalize_shader_io(consumer
->ir
, ir_var_shader_in
);
2111 canonicalize_shader_io(producer
->ir
, ir_var_shader_out
);
2114 linker::populate_consumer_input_sets(mem_ctx
, consumer
->ir
,
2116 consumer_interface_inputs
,
2117 consumer_inputs_with_locations
);
2120 foreach_in_list(ir_instruction
, node
, producer
->ir
) {
2121 ir_variable
*const output_var
= node
->as_variable();
2123 if (output_var
== NULL
|| output_var
->data
.mode
!= ir_var_shader_out
)
2126 /* Only geometry shaders can use non-zero streams */
2127 assert(output_var
->data
.stream
== 0 ||
2128 (output_var
->data
.stream
< MAX_VERTEX_STREAMS
&&
2129 producer
->Stage
== MESA_SHADER_GEOMETRY
));
2131 if (num_tfeedback_decls
> 0) {
2132 tfeedback_candidate_generator
g(mem_ctx
, tfeedback_candidates
);
2133 g
.process(output_var
);
2136 ir_variable
*const input_var
=
2137 linker::get_matching_input(mem_ctx
, output_var
, consumer_inputs
,
2138 consumer_interface_inputs
,
2139 consumer_inputs_with_locations
);
2141 /* If a matching input variable was found, add this output (and the
2142 * input) to the set. If this is a separable program and there is no
2143 * consumer stage, add the output.
2145 * Always add TCS outputs. They are shared by all invocations
2146 * within a patch and can be used as shared memory.
2148 if (input_var
|| (prog
->SeparateShader
&& consumer
== NULL
) ||
2149 producer
->Stage
== MESA_SHADER_TESS_CTRL
) {
2150 matches
.record(output_var
, input_var
);
2153 /* Only stream 0 outputs can be consumed in the next stage */
2154 if (input_var
&& output_var
->data
.stream
!= 0) {
2155 linker_error(prog
, "output %s is assigned to stream=%d but "
2156 "is linked to an input, which requires stream=0",
2157 output_var
->name
, output_var
->data
.stream
);
2162 /* If there's no producer stage, then this must be a separable program.
2163 * For example, we may have a program that has just a fragment shader.
2164 * Later this program will be used with some arbitrary vertex (or
2165 * geometry) shader program. This means that locations must be assigned
2166 * for all the inputs.
2168 foreach_in_list(ir_instruction
, node
, consumer
->ir
) {
2169 ir_variable
*const input_var
= node
->as_variable();
2171 if (input_var
== NULL
|| input_var
->data
.mode
!= ir_var_shader_in
)
2174 matches
.record(NULL
, input_var
);
2178 hash_table_dtor(consumer_inputs
);
2179 hash_table_dtor(consumer_interface_inputs
);
2181 for (unsigned i
= 0; i
< num_tfeedback_decls
; ++i
) {
2182 if (!tfeedback_decls
[i
].is_varying())
2185 const tfeedback_candidate
*matched_candidate
2186 = tfeedback_decls
[i
].find_candidate(prog
, tfeedback_candidates
);
2188 if (matched_candidate
== NULL
) {
2189 hash_table_dtor(tfeedback_candidates
);
2193 if (matched_candidate
->toplevel_var
->data
.is_unmatched_generic_inout
) {
2194 matched_candidate
->toplevel_var
->data
.is_xfb_only
= 1;
2195 matches
.record(matched_candidate
->toplevel_var
, NULL
);
2199 const unsigned slots_used
= matches
.assign_locations(prog
, reserved_slots
);
2200 matches
.store_locations();
2202 for (unsigned i
= 0; i
< num_tfeedback_decls
; ++i
) {
2203 if (!tfeedback_decls
[i
].is_varying())
2206 if (!tfeedback_decls
[i
].assign_location(ctx
, prog
)) {
2207 hash_table_dtor(tfeedback_candidates
);
2211 hash_table_dtor(tfeedback_candidates
);
2213 if (consumer
&& producer
) {
2214 foreach_in_list(ir_instruction
, node
, consumer
->ir
) {
2215 ir_variable
*const var
= node
->as_variable();
2217 if (var
&& var
->data
.mode
== ir_var_shader_in
&&
2218 var
->data
.is_unmatched_generic_inout
) {
2219 if (!prog
->IsES
&& prog
->Version
<= 120) {
2220 /* On page 25 (page 31 of the PDF) of the GLSL 1.20 spec:
2222 * Only those varying variables used (i.e. read) in
2223 * the fragment shader executable must be written to
2224 * by the vertex shader executable; declaring
2225 * superfluous varying variables in a vertex shader is
2228 * We interpret this text as meaning that the VS must
2229 * write the variable for the FS to read it. See
2230 * "glsl1-varying read but not written" in piglit.
2232 linker_error(prog
, "%s shader varying %s not written "
2234 _mesa_shader_stage_to_string(consumer
->Stage
),
2236 _mesa_shader_stage_to_string(producer
->Stage
));
2238 linker_warning(prog
, "%s shader varying %s not written "
2240 _mesa_shader_stage_to_string(consumer
->Stage
),
2242 _mesa_shader_stage_to_string(producer
->Stage
));
2247 /* Now that validation is done its safe to remove unused varyings. As
2248 * we have both a producer and consumer its safe to remove unused
2249 * varyings even if the program is a SSO because the stages are being
2250 * linked together i.e. we have a multi-stage SSO.
2252 remove_unused_shader_inputs_and_outputs(false, producer
,
2254 remove_unused_shader_inputs_and_outputs(false, consumer
,
2259 lower_packed_varyings(mem_ctx
, slots_used
, ir_var_shader_out
,
2260 0, producer
, disable_varying_packing
,
2265 lower_packed_varyings(mem_ctx
, slots_used
, ir_var_shader_in
,
2266 consumer_vertices
, consumer
,
2267 disable_varying_packing
, xfb_enabled
);
2274 check_against_output_limit(struct gl_context
*ctx
,
2275 struct gl_shader_program
*prog
,
2276 gl_linked_shader
*producer
,
2277 unsigned num_explicit_locations
)
2279 unsigned output_vectors
= num_explicit_locations
;
2281 foreach_in_list(ir_instruction
, node
, producer
->ir
) {
2282 ir_variable
*const var
= node
->as_variable();
2284 if (var
&& !var
->data
.explicit_location
&&
2285 var
->data
.mode
== ir_var_shader_out
&&
2286 var_counts_against_varying_limit(producer
->Stage
, var
)) {
2287 /* outputs for fragment shader can't be doubles */
2288 output_vectors
+= var
->type
->count_attribute_slots(false);
2292 assert(producer
->Stage
!= MESA_SHADER_FRAGMENT
);
2293 unsigned max_output_components
=
2294 ctx
->Const
.Program
[producer
->Stage
].MaxOutputComponents
;
2296 const unsigned output_components
= output_vectors
* 4;
2297 if (output_components
> max_output_components
) {
2298 if (ctx
->API
== API_OPENGLES2
|| prog
->IsES
)
2299 linker_error(prog
, "%s shader uses too many output vectors "
2301 _mesa_shader_stage_to_string(producer
->Stage
),
2303 max_output_components
/ 4);
2305 linker_error(prog
, "%s shader uses too many output components "
2307 _mesa_shader_stage_to_string(producer
->Stage
),
2309 max_output_components
);
2318 check_against_input_limit(struct gl_context
*ctx
,
2319 struct gl_shader_program
*prog
,
2320 gl_linked_shader
*consumer
,
2321 unsigned num_explicit_locations
)
2323 unsigned input_vectors
= num_explicit_locations
;
2325 foreach_in_list(ir_instruction
, node
, consumer
->ir
) {
2326 ir_variable
*const var
= node
->as_variable();
2328 if (var
&& !var
->data
.explicit_location
&&
2329 var
->data
.mode
== ir_var_shader_in
&&
2330 var_counts_against_varying_limit(consumer
->Stage
, var
)) {
2331 /* vertex inputs aren't varying counted */
2332 input_vectors
+= var
->type
->count_attribute_slots(false);
2336 assert(consumer
->Stage
!= MESA_SHADER_VERTEX
);
2337 unsigned max_input_components
=
2338 ctx
->Const
.Program
[consumer
->Stage
].MaxInputComponents
;
2340 const unsigned input_components
= input_vectors
* 4;
2341 if (input_components
> max_input_components
) {
2342 if (ctx
->API
== API_OPENGLES2
|| prog
->IsES
)
2343 linker_error(prog
, "%s shader uses too many input vectors "
2345 _mesa_shader_stage_to_string(consumer
->Stage
),
2347 max_input_components
/ 4);
2349 linker_error(prog
, "%s shader uses too many input components "
2351 _mesa_shader_stage_to_string(consumer
->Stage
),
2353 max_input_components
);