2 * Copyright © 2012 Intel Corporation
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5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
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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
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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 * Validate the types and qualifiers of an output from one stage against the
45 * matching input to another stage.
48 cross_validate_types_and_qualifiers(struct gl_shader_program
*prog
,
49 const ir_variable
*input
,
50 const ir_variable
*output
,
51 gl_shader_stage consumer_stage
,
52 gl_shader_stage producer_stage
)
54 /* Check that the types match between stages.
56 const glsl_type
*type_to_match
= input
->type
;
58 /* VS -> GS, VS -> TCS, VS -> TES, TES -> GS */
59 const bool extra_array_level
= (producer_stage
== MESA_SHADER_VERTEX
&&
60 consumer_stage
!= MESA_SHADER_FRAGMENT
) ||
61 consumer_stage
== MESA_SHADER_GEOMETRY
;
62 if (extra_array_level
) {
63 assert(type_to_match
->is_array());
64 type_to_match
= type_to_match
->fields
.array
;
67 if (type_to_match
!= output
->type
) {
68 /* There is a bit of a special case for gl_TexCoord. This
69 * built-in is unsized by default. Applications that variable
70 * access it must redeclare it with a size. There is some
71 * language in the GLSL spec that implies the fragment shader
72 * and vertex shader do not have to agree on this size. Other
73 * driver behave this way, and one or two applications seem to
76 * Neither declaration needs to be modified here because the array
77 * sizes are fixed later when update_array_sizes is called.
79 * From page 48 (page 54 of the PDF) of the GLSL 1.10 spec:
81 * "Unlike user-defined varying variables, the built-in
82 * varying variables don't have a strict one-to-one
83 * correspondence between the vertex language and the
86 if (!output
->type
->is_array() || !is_gl_identifier(output
->name
)) {
88 "%s shader output `%s' declared as type `%s', "
89 "but %s shader input declared as type `%s'\n",
90 _mesa_shader_stage_to_string(producer_stage
),
93 _mesa_shader_stage_to_string(consumer_stage
),
99 /* Check that all of the qualifiers match between stages.
101 if (input
->data
.centroid
!= output
->data
.centroid
) {
103 "%s shader output `%s' %s centroid qualifier, "
104 "but %s shader input %s centroid qualifier\n",
105 _mesa_shader_stage_to_string(producer_stage
),
107 (output
->data
.centroid
) ? "has" : "lacks",
108 _mesa_shader_stage_to_string(consumer_stage
),
109 (input
->data
.centroid
) ? "has" : "lacks");
113 if (input
->data
.sample
!= output
->data
.sample
) {
115 "%s shader output `%s' %s sample qualifier, "
116 "but %s shader input %s sample qualifier\n",
117 _mesa_shader_stage_to_string(producer_stage
),
119 (output
->data
.sample
) ? "has" : "lacks",
120 _mesa_shader_stage_to_string(consumer_stage
),
121 (input
->data
.sample
) ? "has" : "lacks");
125 if (input
->data
.patch
!= output
->data
.patch
) {
127 "%s shader output `%s' %s patch qualifier, "
128 "but %s shader input %s patch qualifier\n",
129 _mesa_shader_stage_to_string(producer_stage
),
131 (output
->data
.patch
) ? "has" : "lacks",
132 _mesa_shader_stage_to_string(consumer_stage
),
133 (input
->data
.patch
) ? "has" : "lacks");
137 if (!prog
->IsES
&& input
->data
.invariant
!= output
->data
.invariant
) {
139 "%s shader output `%s' %s invariant qualifier, "
140 "but %s shader input %s invariant qualifier\n",
141 _mesa_shader_stage_to_string(producer_stage
),
143 (output
->data
.invariant
) ? "has" : "lacks",
144 _mesa_shader_stage_to_string(consumer_stage
),
145 (input
->data
.invariant
) ? "has" : "lacks");
149 /* GLSL >= 4.40 removes text requiring interpolation qualifiers
150 * to match cross stage, they must only match within the same stage.
152 * From page 84 (page 90 of the PDF) of the GLSL 4.40 spec:
154 * "It is a link-time error if, within the same stage, the interpolation
155 * qualifiers of variables of the same name do not match.
158 if (input
->data
.interpolation
!= output
->data
.interpolation
&&
159 prog
->Version
< 440) {
161 "%s shader output `%s' specifies %s "
162 "interpolation qualifier, "
163 "but %s shader input specifies %s "
164 "interpolation qualifier\n",
165 _mesa_shader_stage_to_string(producer_stage
),
167 interpolation_string(output
->data
.interpolation
),
168 _mesa_shader_stage_to_string(consumer_stage
),
169 interpolation_string(input
->data
.interpolation
));
175 * Validate front and back color outputs against single color input
178 cross_validate_front_and_back_color(struct gl_shader_program
*prog
,
179 const ir_variable
*input
,
180 const ir_variable
*front_color
,
181 const ir_variable
*back_color
,
182 gl_shader_stage consumer_stage
,
183 gl_shader_stage producer_stage
)
185 if (front_color
!= NULL
&& front_color
->data
.assigned
)
186 cross_validate_types_and_qualifiers(prog
, input
, front_color
,
187 consumer_stage
, producer_stage
);
189 if (back_color
!= NULL
&& back_color
->data
.assigned
)
190 cross_validate_types_and_qualifiers(prog
, input
, back_color
,
191 consumer_stage
, producer_stage
);
195 * Validate that outputs from one stage match inputs of another
198 cross_validate_outputs_to_inputs(struct gl_shader_program
*prog
,
199 gl_shader
*producer
, gl_shader
*consumer
)
201 glsl_symbol_table parameters
;
202 ir_variable
*explicit_locations
[MAX_VARYING
] = { NULL
, };
204 /* Find all shader outputs in the "producer" stage.
206 foreach_in_list(ir_instruction
, node
, producer
->ir
) {
207 ir_variable
*const var
= node
->as_variable();
209 if ((var
== NULL
) || (var
->data
.mode
!= ir_var_shader_out
))
212 if (!var
->data
.explicit_location
213 || var
->data
.location
< VARYING_SLOT_VAR0
)
214 parameters
.add_variable(var
);
216 /* User-defined varyings with explicit locations are handled
217 * differently because they do not need to have matching names.
219 const unsigned idx
= var
->data
.location
- VARYING_SLOT_VAR0
;
221 if (explicit_locations
[idx
] != NULL
) {
223 "%s shader has multiple outputs explicitly "
224 "assigned to location %d\n",
225 _mesa_shader_stage_to_string(producer
->Stage
),
230 explicit_locations
[idx
] = var
;
235 /* Find all shader inputs in the "consumer" stage. Any variables that have
236 * matching outputs already in the symbol table must have the same type and
239 * Exception: if the consumer is the geometry shader, then the inputs
240 * should be arrays and the type of the array element should match the type
241 * of the corresponding producer output.
243 foreach_in_list(ir_instruction
, node
, consumer
->ir
) {
244 ir_variable
*const input
= node
->as_variable();
246 if ((input
== NULL
) || (input
->data
.mode
!= ir_var_shader_in
))
249 if (strcmp(input
->name
, "gl_Color") == 0 && input
->data
.used
) {
250 const ir_variable
*const front_color
=
251 parameters
.get_variable("gl_FrontColor");
253 const ir_variable
*const back_color
=
254 parameters
.get_variable("gl_BackColor");
256 cross_validate_front_and_back_color(prog
, input
,
257 front_color
, back_color
,
258 consumer
->Stage
, producer
->Stage
);
259 } else if (strcmp(input
->name
, "gl_SecondaryColor") == 0 && input
->data
.used
) {
260 const ir_variable
*const front_color
=
261 parameters
.get_variable("gl_FrontSecondaryColor");
263 const ir_variable
*const back_color
=
264 parameters
.get_variable("gl_BackSecondaryColor");
266 cross_validate_front_and_back_color(prog
, input
,
267 front_color
, back_color
,
268 consumer
->Stage
, producer
->Stage
);
270 /* The rules for connecting inputs and outputs change in the presence
271 * of explicit locations. In this case, we no longer care about the
272 * names of the variables. Instead, we care only about the
273 * explicitly assigned location.
275 ir_variable
*output
= NULL
;
276 if (input
->data
.explicit_location
277 && input
->data
.location
>= VARYING_SLOT_VAR0
) {
278 output
= explicit_locations
[input
->data
.location
- VARYING_SLOT_VAR0
];
280 if (output
== NULL
) {
282 "%s shader input `%s' with explicit location "
283 "has no matching output\n",
284 _mesa_shader_stage_to_string(consumer
->Stage
),
288 output
= parameters
.get_variable(input
->name
);
291 if (output
!= NULL
) {
292 cross_validate_types_and_qualifiers(prog
, input
, output
,
293 consumer
->Stage
, producer
->Stage
);
295 /* Check for input vars with unmatched output vars in prev stage
296 * taking into account that interface blocks could have a matching
297 * output but with different name, so we ignore them.
299 assert(!input
->data
.assigned
);
300 if (input
->data
.used
&& !input
->get_interface_type() &&
301 !input
->data
.explicit_location
&& !prog
->SeparateShader
)
303 "%s shader input `%s' "
304 "has no matching output in the previous stage\n",
305 _mesa_shader_stage_to_string(consumer
->Stage
),
314 * Initialize this object based on a string that was passed to
315 * glTransformFeedbackVaryings.
317 * If the input is mal-formed, this call still succeeds, but it sets
318 * this->var_name to a mal-formed input, so tfeedback_decl::find_output_var()
319 * will fail to find any matching variable.
322 tfeedback_decl::init(struct gl_context
*ctx
, const void *mem_ctx
,
325 /* We don't have to be pedantic about what is a valid GLSL variable name,
326 * because any variable with an invalid name can't exist in the IR anyway.
330 this->orig_name
= input
;
331 this->lowered_builtin_array_variable
= none
;
332 this->skip_components
= 0;
333 this->next_buffer_separator
= false;
334 this->matched_candidate
= NULL
;
337 if (ctx
->Extensions
.ARB_transform_feedback3
) {
338 /* Parse gl_NextBuffer. */
339 if (strcmp(input
, "gl_NextBuffer") == 0) {
340 this->next_buffer_separator
= true;
344 /* Parse gl_SkipComponents. */
345 if (strcmp(input
, "gl_SkipComponents1") == 0)
346 this->skip_components
= 1;
347 else if (strcmp(input
, "gl_SkipComponents2") == 0)
348 this->skip_components
= 2;
349 else if (strcmp(input
, "gl_SkipComponents3") == 0)
350 this->skip_components
= 3;
351 else if (strcmp(input
, "gl_SkipComponents4") == 0)
352 this->skip_components
= 4;
354 if (this->skip_components
)
358 /* Parse a declaration. */
359 const char *base_name_end
;
360 long subscript
= parse_program_resource_name(input
, &base_name_end
);
361 this->var_name
= ralloc_strndup(mem_ctx
, input
, base_name_end
- input
);
362 if (this->var_name
== NULL
) {
363 _mesa_error_no_memory(__func__
);
367 if (subscript
>= 0) {
368 this->array_subscript
= subscript
;
369 this->is_subscripted
= true;
371 this->is_subscripted
= false;
374 /* For drivers that lower gl_ClipDistance to gl_ClipDistanceMESA, this
375 * class must behave specially to account for the fact that gl_ClipDistance
376 * is converted from a float[8] to a vec4[2].
378 if (ctx
->Const
.ShaderCompilerOptions
[MESA_SHADER_VERTEX
].LowerClipDistance
&&
379 strcmp(this->var_name
, "gl_ClipDistance") == 0) {
380 this->lowered_builtin_array_variable
= clip_distance
;
383 if (ctx
->Const
.LowerTessLevel
&&
384 (strcmp(this->var_name
, "gl_TessLevelOuter") == 0))
385 this->lowered_builtin_array_variable
= tess_level_outer
;
386 if (ctx
->Const
.LowerTessLevel
&&
387 (strcmp(this->var_name
, "gl_TessLevelInner") == 0))
388 this->lowered_builtin_array_variable
= tess_level_inner
;
393 * Determine whether two tfeedback_decl objects refer to the same variable and
394 * array index (if applicable).
397 tfeedback_decl::is_same(const tfeedback_decl
&x
, const tfeedback_decl
&y
)
399 assert(x
.is_varying() && y
.is_varying());
401 if (strcmp(x
.var_name
, y
.var_name
) != 0)
403 if (x
.is_subscripted
!= y
.is_subscripted
)
405 if (x
.is_subscripted
&& x
.array_subscript
!= y
.array_subscript
)
412 * Assign a location and stream ID for this tfeedback_decl object based on the
413 * transform feedback candidate found by find_candidate.
415 * If an error occurs, the error is reported through linker_error() and false
419 tfeedback_decl::assign_location(struct gl_context
*ctx
,
420 struct gl_shader_program
*prog
)
422 assert(this->is_varying());
424 unsigned fine_location
425 = this->matched_candidate
->toplevel_var
->data
.location
* 4
426 + this->matched_candidate
->toplevel_var
->data
.location_frac
427 + this->matched_candidate
->offset
;
429 if (this->matched_candidate
->type
->is_array()) {
431 const unsigned matrix_cols
=
432 this->matched_candidate
->type
->fields
.array
->matrix_columns
;
433 const unsigned vector_elements
=
434 this->matched_candidate
->type
->fields
.array
->vector_elements
;
435 const unsigned dmul
=
436 this->matched_candidate
->type
->fields
.array
->is_double() ? 2 : 1;
437 unsigned actual_array_size
;
438 switch (this->lowered_builtin_array_variable
) {
440 actual_array_size
= prog
->LastClipDistanceArraySize
;
442 case tess_level_outer
:
443 actual_array_size
= 4;
445 case tess_level_inner
:
446 actual_array_size
= 2;
450 actual_array_size
= this->matched_candidate
->type
->array_size();
454 if (this->is_subscripted
) {
455 /* Check array bounds. */
456 if (this->array_subscript
>= actual_array_size
) {
457 linker_error(prog
, "Transform feedback varying %s has index "
458 "%i, but the array size is %u.",
459 this->orig_name
, this->array_subscript
,
463 unsigned array_elem_size
= this->lowered_builtin_array_variable
?
464 1 : vector_elements
* matrix_cols
* dmul
;
465 fine_location
+= array_elem_size
* this->array_subscript
;
468 this->size
= actual_array_size
;
470 this->vector_elements
= vector_elements
;
471 this->matrix_columns
= matrix_cols
;
472 if (this->lowered_builtin_array_variable
)
473 this->type
= GL_FLOAT
;
475 this->type
= this->matched_candidate
->type
->fields
.array
->gl_type
;
477 /* Regular variable (scalar, vector, or matrix) */
478 if (this->is_subscripted
) {
479 linker_error(prog
, "Transform feedback varying %s requested, "
480 "but %s is not an array.",
481 this->orig_name
, this->var_name
);
485 this->vector_elements
= this->matched_candidate
->type
->vector_elements
;
486 this->matrix_columns
= this->matched_candidate
->type
->matrix_columns
;
487 this->type
= this->matched_candidate
->type
->gl_type
;
489 this->location
= fine_location
/ 4;
490 this->location_frac
= fine_location
% 4;
492 /* From GL_EXT_transform_feedback:
493 * A program will fail to link if:
495 * * the total number of components to capture in any varying
496 * variable in <varyings> is greater than the constant
497 * MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS_EXT and the
498 * buffer mode is SEPARATE_ATTRIBS_EXT;
500 if (prog
->TransformFeedback
.BufferMode
== GL_SEPARATE_ATTRIBS
&&
501 this->num_components() >
502 ctx
->Const
.MaxTransformFeedbackSeparateComponents
) {
503 linker_error(prog
, "Transform feedback varying %s exceeds "
504 "MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS.",
509 /* Only transform feedback varyings can be assigned to non-zero streams,
510 * so assign the stream id here.
512 this->stream_id
= this->matched_candidate
->toplevel_var
->data
.stream
;
519 tfeedback_decl::get_num_outputs() const
521 if (!this->is_varying()) {
524 return (this->num_components() + this->location_frac
+ 3)/4;
529 * Update gl_transform_feedback_info to reflect this tfeedback_decl.
531 * If an error occurs, the error is reported through linker_error() and false
535 tfeedback_decl::store(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
536 struct gl_transform_feedback_info
*info
,
537 unsigned buffer
, const unsigned max_outputs
) const
539 assert(!this->next_buffer_separator
);
541 /* Handle gl_SkipComponents. */
542 if (this->skip_components
) {
543 info
->BufferStride
[buffer
] += this->skip_components
;
547 /* From GL_EXT_transform_feedback:
548 * A program will fail to link if:
550 * * the total number of components to capture is greater than
551 * the constant MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS_EXT
552 * and the buffer mode is INTERLEAVED_ATTRIBS_EXT.
554 if (prog
->TransformFeedback
.BufferMode
== GL_INTERLEAVED_ATTRIBS
&&
555 info
->BufferStride
[buffer
] + this->num_components() >
556 ctx
->Const
.MaxTransformFeedbackInterleavedComponents
) {
557 linker_error(prog
, "The MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS "
558 "limit has been exceeded.");
562 unsigned location
= this->location
;
563 unsigned location_frac
= this->location_frac
;
564 unsigned num_components
= this->num_components();
565 while (num_components
> 0) {
566 unsigned output_size
= MIN2(num_components
, 4 - location_frac
);
567 assert(info
->NumOutputs
< max_outputs
);
568 info
->Outputs
[info
->NumOutputs
].ComponentOffset
= location_frac
;
569 info
->Outputs
[info
->NumOutputs
].OutputRegister
= location
;
570 info
->Outputs
[info
->NumOutputs
].NumComponents
= output_size
;
571 info
->Outputs
[info
->NumOutputs
].StreamId
= stream_id
;
572 info
->Outputs
[info
->NumOutputs
].OutputBuffer
= buffer
;
573 info
->Outputs
[info
->NumOutputs
].DstOffset
= info
->BufferStride
[buffer
];
575 info
->BufferStride
[buffer
] += output_size
;
576 info
->BufferStream
[buffer
] = this->stream_id
;
577 num_components
-= output_size
;
582 info
->Varyings
[info
->NumVarying
].Name
= ralloc_strdup(prog
, this->orig_name
);
583 info
->Varyings
[info
->NumVarying
].Type
= this->type
;
584 info
->Varyings
[info
->NumVarying
].Size
= this->size
;
591 const tfeedback_candidate
*
592 tfeedback_decl::find_candidate(gl_shader_program
*prog
,
593 hash_table
*tfeedback_candidates
)
595 const char *name
= this->var_name
;
596 switch (this->lowered_builtin_array_variable
) {
598 name
= this->var_name
;
601 name
= "gl_ClipDistanceMESA";
603 case tess_level_outer
:
604 name
= "gl_TessLevelOuterMESA";
606 case tess_level_inner
:
607 name
= "gl_TessLevelInnerMESA";
610 this->matched_candidate
= (const tfeedback_candidate
*)
611 hash_table_find(tfeedback_candidates
, name
);
612 if (!this->matched_candidate
) {
613 /* From GL_EXT_transform_feedback:
614 * A program will fail to link if:
616 * * any variable name specified in the <varyings> array is not
617 * declared as an output in the geometry shader (if present) or
618 * the vertex shader (if no geometry shader is present);
620 linker_error(prog
, "Transform feedback varying %s undeclared.",
623 return this->matched_candidate
;
628 * Parse all the transform feedback declarations that were passed to
629 * glTransformFeedbackVaryings() and store them in tfeedback_decl objects.
631 * If an error occurs, the error is reported through linker_error() and false
635 parse_tfeedback_decls(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
636 const void *mem_ctx
, unsigned num_names
,
637 char **varying_names
, tfeedback_decl
*decls
)
639 for (unsigned i
= 0; i
< num_names
; ++i
) {
640 decls
[i
].init(ctx
, mem_ctx
, varying_names
[i
]);
642 if (!decls
[i
].is_varying())
645 /* From GL_EXT_transform_feedback:
646 * A program will fail to link if:
648 * * any two entries in the <varyings> array specify the same varying
651 * We interpret this to mean "any two entries in the <varyings> array
652 * specify the same varying variable and array index", since transform
653 * feedback of arrays would be useless otherwise.
655 for (unsigned j
= 0; j
< i
; ++j
) {
656 if (!decls
[j
].is_varying())
659 if (tfeedback_decl::is_same(decls
[i
], decls
[j
])) {
660 linker_error(prog
, "Transform feedback varying %s specified "
661 "more than once.", varying_names
[i
]);
671 * Store transform feedback location assignments into
672 * prog->LinkedTransformFeedback based on the data stored in tfeedback_decls.
674 * If an error occurs, the error is reported through linker_error() and false
678 store_tfeedback_info(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
679 unsigned num_tfeedback_decls
,
680 tfeedback_decl
*tfeedback_decls
)
682 bool separate_attribs_mode
=
683 prog
->TransformFeedback
.BufferMode
== GL_SEPARATE_ATTRIBS
;
685 ralloc_free(prog
->LinkedTransformFeedback
.Varyings
);
686 ralloc_free(prog
->LinkedTransformFeedback
.Outputs
);
688 memset(&prog
->LinkedTransformFeedback
, 0,
689 sizeof(prog
->LinkedTransformFeedback
));
691 prog
->LinkedTransformFeedback
.Varyings
=
693 struct gl_transform_feedback_varying_info
,
694 num_tfeedback_decls
);
696 unsigned num_outputs
= 0;
697 for (unsigned i
= 0; i
< num_tfeedback_decls
; ++i
)
698 num_outputs
+= tfeedback_decls
[i
].get_num_outputs();
700 prog
->LinkedTransformFeedback
.Outputs
=
702 struct gl_transform_feedback_output
,
705 unsigned num_buffers
= 0;
707 if (separate_attribs_mode
) {
708 /* GL_SEPARATE_ATTRIBS */
709 for (unsigned i
= 0; i
< num_tfeedback_decls
; ++i
) {
710 if (!tfeedback_decls
[i
].store(ctx
, prog
, &prog
->LinkedTransformFeedback
,
711 num_buffers
, num_outputs
))
718 /* GL_INVERLEAVED_ATTRIBS */
719 int buffer_stream_id
= -1;
720 for (unsigned i
= 0; i
< num_tfeedback_decls
; ++i
) {
721 if (tfeedback_decls
[i
].is_next_buffer_separator()) {
723 buffer_stream_id
= -1;
725 } else if (buffer_stream_id
== -1) {
726 /* First varying writing to this buffer: remember its stream */
727 buffer_stream_id
= (int) tfeedback_decls
[i
].get_stream_id();
728 } else if (buffer_stream_id
!=
729 (int) tfeedback_decls
[i
].get_stream_id()) {
730 /* Varying writes to the same buffer from a different stream */
732 "Transform feedback can't capture varyings belonging "
733 "to different vertex streams in a single buffer. "
734 "Varying %s writes to buffer from stream %u, other "
735 "varyings in the same buffer write from stream %u.",
736 tfeedback_decls
[i
].name(),
737 tfeedback_decls
[i
].get_stream_id(),
742 if (!tfeedback_decls
[i
].store(ctx
, prog
,
743 &prog
->LinkedTransformFeedback
,
744 num_buffers
, num_outputs
))
750 assert(prog
->LinkedTransformFeedback
.NumOutputs
== num_outputs
);
752 prog
->LinkedTransformFeedback
.NumBuffers
= num_buffers
;
759 * Data structure recording the relationship between outputs of one shader
760 * stage (the "producer") and inputs of another (the "consumer").
762 class varying_matches
765 varying_matches(bool disable_varying_packing
,
766 gl_shader_stage producer_stage
,
767 gl_shader_stage consumer_stage
);
769 void record(ir_variable
*producer_var
, ir_variable
*consumer_var
);
770 unsigned assign_locations(uint64_t reserved_slots
, bool separate_shader
);
771 void store_locations() const;
775 * If true, this driver disables varying packing, so all varyings need to
776 * be aligned on slot boundaries, and take up a number of slots equal to
777 * their number of matrix columns times their array size.
779 const bool disable_varying_packing
;
782 * Enum representing the order in which varyings are packed within a
785 * Currently we pack vec4's first, then vec2's, then scalar values, then
786 * vec3's. This order ensures that the only vectors that are at risk of
787 * having to be "double parked" (split between two adjacent varying slots)
790 enum packing_order_enum
{
793 PACKING_ORDER_SCALAR
,
797 static unsigned compute_packing_class(const ir_variable
*var
);
798 static packing_order_enum
compute_packing_order(const ir_variable
*var
);
799 static int match_comparator(const void *x_generic
, const void *y_generic
);
802 * Structure recording the relationship between a single producer output
803 * and a single consumer input.
807 * Packing class for this varying, computed by compute_packing_class().
809 unsigned packing_class
;
812 * Packing order for this varying, computed by compute_packing_order().
814 packing_order_enum packing_order
;
815 unsigned num_components
;
818 * The output variable in the producer stage.
820 ir_variable
*producer_var
;
823 * The input variable in the consumer stage.
825 ir_variable
*consumer_var
;
828 * The location which has been assigned for this varying. This is
829 * expressed in multiples of a float, with the first generic varying
830 * (i.e. the one referred to by VARYING_SLOT_VAR0) represented by the
833 unsigned generic_location
;
837 * The number of elements in the \c matches array that are currently in
840 unsigned num_matches
;
843 * The number of elements that were set aside for the \c matches array when
846 unsigned matches_capacity
;
848 gl_shader_stage producer_stage
;
849 gl_shader_stage consumer_stage
;
852 } /* anonymous namespace */
854 varying_matches::varying_matches(bool disable_varying_packing
,
855 gl_shader_stage producer_stage
,
856 gl_shader_stage consumer_stage
)
857 : disable_varying_packing(disable_varying_packing
),
858 producer_stage(producer_stage
),
859 consumer_stage(consumer_stage
)
861 /* Note: this initial capacity is rather arbitrarily chosen to be large
862 * enough for many cases without wasting an unreasonable amount of space.
863 * varying_matches::record() will resize the array if there are more than
864 * this number of varyings.
866 this->matches_capacity
= 8;
867 this->matches
= (match
*)
868 malloc(sizeof(*this->matches
) * this->matches_capacity
);
869 this->num_matches
= 0;
873 varying_matches::~varying_matches()
880 * Record the given producer/consumer variable pair in the list of variables
881 * that should later be assigned locations.
883 * It is permissible for \c consumer_var to be NULL (this happens if a
884 * variable is output by the producer and consumed by transform feedback, but
885 * not consumed by the consumer).
887 * If \c producer_var has already been paired up with a consumer_var, or
888 * producer_var is part of fixed pipeline functionality (and hence already has
889 * a location assigned), this function has no effect.
891 * Note: as a side effect this function may change the interpolation type of
892 * \c producer_var, but only when the change couldn't possibly affect
896 varying_matches::record(ir_variable
*producer_var
, ir_variable
*consumer_var
)
898 assert(producer_var
!= NULL
|| consumer_var
!= NULL
);
900 if ((producer_var
&& (!producer_var
->data
.is_unmatched_generic_inout
||
901 producer_var
->data
.explicit_location
)) ||
902 (consumer_var
&& (!consumer_var
->data
.is_unmatched_generic_inout
||
903 consumer_var
->data
.explicit_location
))) {
904 /* Either a location already exists for this variable (since it is part
905 * of fixed functionality), or it has already been recorded as part of a
911 if ((consumer_var
== NULL
&& producer_var
->type
->contains_integer()) ||
912 consumer_stage
!= MESA_SHADER_FRAGMENT
) {
913 /* Since this varying is not being consumed by the fragment shader, its
914 * interpolation type varying cannot possibly affect rendering. Also,
915 * this variable is non-flat and is (or contains) an integer.
917 * lower_packed_varyings requires all integer varyings to flat,
918 * regardless of where they appear. We can trivially satisfy that
919 * requirement by changing the interpolation type to flat here.
922 producer_var
->data
.centroid
= false;
923 producer_var
->data
.sample
= false;
924 producer_var
->data
.interpolation
= INTERP_QUALIFIER_FLAT
;
928 consumer_var
->data
.centroid
= false;
929 consumer_var
->data
.sample
= false;
930 consumer_var
->data
.interpolation
= INTERP_QUALIFIER_FLAT
;
934 if (this->num_matches
== this->matches_capacity
) {
935 this->matches_capacity
*= 2;
936 this->matches
= (match
*)
937 realloc(this->matches
,
938 sizeof(*this->matches
) * this->matches_capacity
);
941 const ir_variable
*const var
= (producer_var
!= NULL
)
942 ? producer_var
: consumer_var
;
944 this->matches
[this->num_matches
].packing_class
945 = this->compute_packing_class(var
);
946 this->matches
[this->num_matches
].packing_order
947 = this->compute_packing_order(var
);
948 if (this->disable_varying_packing
) {
949 const struct glsl_type
*type
= var
->type
;
952 /* Some shader stages have 2-dimensional varyings. Use the inner type. */
953 if (!var
->data
.patch
&&
954 ((var
== producer_var
&& producer_stage
== MESA_SHADER_TESS_CTRL
) ||
955 (var
== consumer_var
&& (consumer_stage
== MESA_SHADER_TESS_CTRL
||
956 consumer_stage
== MESA_SHADER_TESS_EVAL
||
957 consumer_stage
== MESA_SHADER_GEOMETRY
)))) {
958 assert(type
->is_array());
959 type
= type
->fields
.array
;
962 slots
= type
->count_attribute_slots(false);
963 this->matches
[this->num_matches
].num_components
= slots
* 4;
965 this->matches
[this->num_matches
].num_components
966 = var
->type
->component_slots();
968 this->matches
[this->num_matches
].producer_var
= producer_var
;
969 this->matches
[this->num_matches
].consumer_var
= consumer_var
;
972 producer_var
->data
.is_unmatched_generic_inout
= 0;
974 consumer_var
->data
.is_unmatched_generic_inout
= 0;
979 * Choose locations for all of the variable matches that were previously
980 * passed to varying_matches::record().
983 varying_matches::assign_locations(uint64_t reserved_slots
, bool separate_shader
)
985 /* We disable varying sorting for separate shader programs for the
988 * 1/ All programs must sort the code in the same order to guarantee the
989 * interface matching. However varying_matches::record() will change the
990 * interpolation qualifier of some stages.
992 * 2/ GLSL version 4.50 removes the matching constrain on the interpolation
995 * From Section 4.5 (Interpolation Qualifiers) of the GLSL 4.40 spec:
997 * "The type and presence of interpolation qualifiers of variables with
998 * the same name declared in all linked shaders for the same cross-stage
999 * interface must match, otherwise the link command will fail.
1001 * When comparing an output from one stage to an input of a subsequent
1002 * stage, the input and output don't match if their interpolation
1003 * qualifiers (or lack thereof) are not the same."
1005 * "It is a link-time error if, within the same stage, the interpolation
1006 * qualifiers of variables of the same name do not match."
1008 if (!separate_shader
) {
1009 /* Sort varying matches into an order that makes them easy to pack. */
1010 qsort(this->matches
, this->num_matches
, sizeof(*this->matches
),
1011 &varying_matches::match_comparator
);
1014 unsigned generic_location
= 0;
1015 unsigned generic_patch_location
= MAX_VARYING
*4;
1017 for (unsigned i
= 0; i
< this->num_matches
; i
++) {
1018 unsigned *location
= &generic_location
;
1020 if ((this->matches
[i
].consumer_var
&&
1021 this->matches
[i
].consumer_var
->data
.patch
) ||
1022 (this->matches
[i
].producer_var
&&
1023 this->matches
[i
].producer_var
->data
.patch
))
1024 location
= &generic_patch_location
;
1026 /* Advance to the next slot if this varying has a different packing
1027 * class than the previous one, and we're not already on a slot
1031 this->matches
[i
- 1].packing_class
1032 != this->matches
[i
].packing_class
) {
1033 *location
= ALIGN(*location
, 4);
1035 while ((*location
< MAX_VARYING
* 4u) &&
1036 (reserved_slots
& (1u << *location
/ 4u))) {
1037 *location
= ALIGN(*location
+ 1, 4);
1040 this->matches
[i
].generic_location
= *location
;
1042 *location
+= this->matches
[i
].num_components
;
1045 return (generic_location
+ 3) / 4;
1050 * Update the producer and consumer shaders to reflect the locations
1051 * assignments that were made by varying_matches::assign_locations().
1054 varying_matches::store_locations() const
1056 for (unsigned i
= 0; i
< this->num_matches
; i
++) {
1057 ir_variable
*producer_var
= this->matches
[i
].producer_var
;
1058 ir_variable
*consumer_var
= this->matches
[i
].consumer_var
;
1059 unsigned generic_location
= this->matches
[i
].generic_location
;
1060 unsigned slot
= generic_location
/ 4;
1061 unsigned offset
= generic_location
% 4;
1064 producer_var
->data
.location
= VARYING_SLOT_VAR0
+ slot
;
1065 producer_var
->data
.location_frac
= offset
;
1069 assert(consumer_var
->data
.location
== -1);
1070 consumer_var
->data
.location
= VARYING_SLOT_VAR0
+ slot
;
1071 consumer_var
->data
.location_frac
= offset
;
1078 * Compute the "packing class" of the given varying. This is an unsigned
1079 * integer with the property that two variables in the same packing class can
1080 * be safely backed into the same vec4.
1083 varying_matches::compute_packing_class(const ir_variable
*var
)
1085 /* Without help from the back-end, there is no way to pack together
1086 * variables with different interpolation types, because
1087 * lower_packed_varyings must choose exactly one interpolation type for
1088 * each packed varying it creates.
1090 * However, we can safely pack together floats, ints, and uints, because:
1092 * - varyings of base type "int" and "uint" must use the "flat"
1093 * interpolation type, which can only occur in GLSL 1.30 and above.
1095 * - On platforms that support GLSL 1.30 and above, lower_packed_varyings
1096 * can store flat floats as ints without losing any information (using
1097 * the ir_unop_bitcast_* opcodes).
1099 * Therefore, the packing class depends only on the interpolation type.
1101 unsigned packing_class
= var
->data
.centroid
| (var
->data
.sample
<< 1) |
1102 (var
->data
.patch
<< 2);
1104 packing_class
+= var
->data
.interpolation
;
1105 return packing_class
;
1110 * Compute the "packing order" of the given varying. This is a sort key we
1111 * use to determine when to attempt to pack the given varying relative to
1112 * other varyings in the same packing class.
1114 varying_matches::packing_order_enum
1115 varying_matches::compute_packing_order(const ir_variable
*var
)
1117 const glsl_type
*element_type
= var
->type
;
1119 while (element_type
->base_type
== GLSL_TYPE_ARRAY
) {
1120 element_type
= element_type
->fields
.array
;
1123 switch (element_type
->component_slots() % 4) {
1124 case 1: return PACKING_ORDER_SCALAR
;
1125 case 2: return PACKING_ORDER_VEC2
;
1126 case 3: return PACKING_ORDER_VEC3
;
1127 case 0: return PACKING_ORDER_VEC4
;
1129 assert(!"Unexpected value of vector_elements");
1130 return PACKING_ORDER_VEC4
;
1136 * Comparison function passed to qsort() to sort varyings by packing_class and
1137 * then by packing_order.
1140 varying_matches::match_comparator(const void *x_generic
, const void *y_generic
)
1142 const match
*x
= (const match
*) x_generic
;
1143 const match
*y
= (const match
*) y_generic
;
1145 if (x
->packing_class
!= y
->packing_class
)
1146 return x
->packing_class
- y
->packing_class
;
1147 return x
->packing_order
- y
->packing_order
;
1152 * Is the given variable a varying variable to be counted against the
1153 * limit in ctx->Const.MaxVarying?
1154 * This includes variables such as texcoords, colors and generic
1155 * varyings, but excludes variables such as gl_FrontFacing and gl_FragCoord.
1158 var_counts_against_varying_limit(gl_shader_stage stage
, const ir_variable
*var
)
1160 /* Only fragment shaders will take a varying variable as an input */
1161 if (stage
== MESA_SHADER_FRAGMENT
&&
1162 var
->data
.mode
== ir_var_shader_in
) {
1163 switch (var
->data
.location
) {
1164 case VARYING_SLOT_POS
:
1165 case VARYING_SLOT_FACE
:
1166 case VARYING_SLOT_PNTC
:
1177 * Visitor class that generates tfeedback_candidate structs describing all
1178 * possible targets of transform feedback.
1180 * tfeedback_candidate structs are stored in the hash table
1181 * tfeedback_candidates, which is passed to the constructor. This hash table
1182 * maps varying names to instances of the tfeedback_candidate struct.
1184 class tfeedback_candidate_generator
: public program_resource_visitor
1187 tfeedback_candidate_generator(void *mem_ctx
,
1188 hash_table
*tfeedback_candidates
)
1190 tfeedback_candidates(tfeedback_candidates
),
1196 void process(ir_variable
*var
)
1198 this->toplevel_var
= var
;
1199 this->varying_floats
= 0;
1200 if (var
->is_interface_instance())
1201 program_resource_visitor::process(var
->get_interface_type(),
1202 var
->get_interface_type()->name
);
1204 program_resource_visitor::process(var
);
1208 virtual void visit_field(const glsl_type
*type
, const char *name
,
1211 assert(!type
->without_array()->is_record());
1212 assert(!type
->without_array()->is_interface());
1216 tfeedback_candidate
*candidate
1217 = rzalloc(this->mem_ctx
, tfeedback_candidate
);
1218 candidate
->toplevel_var
= this->toplevel_var
;
1219 candidate
->type
= type
;
1220 candidate
->offset
= this->varying_floats
;
1221 hash_table_insert(this->tfeedback_candidates
, candidate
,
1222 ralloc_strdup(this->mem_ctx
, name
));
1223 this->varying_floats
+= type
->component_slots();
1227 * Memory context used to allocate hash table keys and values.
1229 void * const mem_ctx
;
1232 * Hash table in which tfeedback_candidate objects should be stored.
1234 hash_table
* const tfeedback_candidates
;
1237 * Pointer to the toplevel variable that is being traversed.
1239 ir_variable
*toplevel_var
;
1242 * Total number of varying floats that have been visited so far. This is
1243 * used to determine the offset to each varying within the toplevel
1246 unsigned varying_floats
;
1253 populate_consumer_input_sets(void *mem_ctx
, exec_list
*ir
,
1254 hash_table
*consumer_inputs
,
1255 hash_table
*consumer_interface_inputs
,
1256 ir_variable
*consumer_inputs_with_locations
[VARYING_SLOT_TESS_MAX
])
1258 memset(consumer_inputs_with_locations
,
1260 sizeof(consumer_inputs_with_locations
[0]) * VARYING_SLOT_TESS_MAX
);
1262 foreach_in_list(ir_instruction
, node
, ir
) {
1263 ir_variable
*const input_var
= node
->as_variable();
1265 if ((input_var
!= NULL
) && (input_var
->data
.mode
== ir_var_shader_in
)) {
1266 if (input_var
->type
->is_interface())
1269 if (input_var
->data
.explicit_location
) {
1270 /* assign_varying_locations only cares about finding the
1271 * ir_variable at the start of a contiguous location block.
1273 * - For !producer, consumer_inputs_with_locations isn't used.
1275 * - For !consumer, consumer_inputs_with_locations is empty.
1277 * For consumer && producer, if you were trying to set some
1278 * ir_variable to the middle of a location block on the other side
1279 * of producer/consumer, cross_validate_outputs_to_inputs() should
1280 * be link-erroring due to either type mismatch or location
1281 * overlaps. If the variables do match up, then they've got a
1282 * matching data.location and you only looked at
1283 * consumer_inputs_with_locations[var->data.location], not any
1284 * following entries for the array/structure.
1286 consumer_inputs_with_locations
[input_var
->data
.location
] =
1288 } else if (input_var
->get_interface_type() != NULL
) {
1289 char *const iface_field_name
=
1290 ralloc_asprintf(mem_ctx
, "%s.%s",
1291 input_var
->get_interface_type()->name
,
1293 hash_table_insert(consumer_interface_inputs
, input_var
,
1296 hash_table_insert(consumer_inputs
, input_var
,
1297 ralloc_strdup(mem_ctx
, input_var
->name
));
1306 * Find a variable from the consumer that "matches" the specified variable
1308 * This function only finds inputs with names that match. There is no
1309 * validation (here) that the types, etc. are compatible.
1312 get_matching_input(void *mem_ctx
,
1313 const ir_variable
*output_var
,
1314 hash_table
*consumer_inputs
,
1315 hash_table
*consumer_interface_inputs
,
1316 ir_variable
*consumer_inputs_with_locations
[VARYING_SLOT_TESS_MAX
])
1318 ir_variable
*input_var
;
1320 if (output_var
->data
.explicit_location
) {
1321 input_var
= consumer_inputs_with_locations
[output_var
->data
.location
];
1322 } else if (output_var
->get_interface_type() != NULL
) {
1323 char *const iface_field_name
=
1324 ralloc_asprintf(mem_ctx
, "%s.%s",
1325 output_var
->get_interface_type()->name
,
1328 (ir_variable
*) hash_table_find(consumer_interface_inputs
,
1332 (ir_variable
*) hash_table_find(consumer_inputs
, output_var
->name
);
1335 return (input_var
== NULL
|| input_var
->data
.mode
!= ir_var_shader_in
)
1342 io_variable_cmp(const void *_a
, const void *_b
)
1344 const ir_variable
*const a
= *(const ir_variable
**) _a
;
1345 const ir_variable
*const b
= *(const ir_variable
**) _b
;
1347 if (a
->data
.explicit_location
&& b
->data
.explicit_location
)
1348 return b
->data
.location
- a
->data
.location
;
1350 if (a
->data
.explicit_location
&& !b
->data
.explicit_location
)
1353 if (!a
->data
.explicit_location
&& b
->data
.explicit_location
)
1356 return -strcmp(a
->name
, b
->name
);
1360 * Sort the shader IO variables into canonical order
1363 canonicalize_shader_io(exec_list
*ir
, enum ir_variable_mode io_mode
)
1365 ir_variable
*var_table
[MAX_PROGRAM_OUTPUTS
* 4];
1366 unsigned num_variables
= 0;
1368 foreach_in_list(ir_instruction
, node
, ir
) {
1369 ir_variable
*const var
= node
->as_variable();
1371 if (var
== NULL
|| var
->data
.mode
!= io_mode
)
1374 /* If we have already encountered more I/O variables that could
1375 * successfully link, bail.
1377 if (num_variables
== ARRAY_SIZE(var_table
))
1380 var_table
[num_variables
++] = var
;
1383 if (num_variables
== 0)
1386 /* Sort the list in reverse order (io_variable_cmp handles this). Later
1387 * we're going to push the variables on to the IR list as a stack, so we
1388 * want the last variable (in canonical order) to be first in the list.
1390 qsort(var_table
, num_variables
, sizeof(var_table
[0]), io_variable_cmp
);
1392 /* Remove the variable from it's current location in the IR, and put it at
1395 for (unsigned i
= 0; i
< num_variables
; i
++) {
1396 var_table
[i
]->remove();
1397 ir
->push_head(var_table
[i
]);
1402 * Generate a bitfield map of the explicit locations for shader varyings.
1404 * In theory a 32 bits value will be enough but a 64 bits value is future proof.
1407 reserved_varying_slot(struct gl_shader
*stage
, ir_variable_mode io_mode
)
1409 assert(io_mode
== ir_var_shader_in
|| io_mode
== ir_var_shader_out
);
1410 assert(MAX_VARYING
<= 64); /* avoid an overflow of the returned value */
1418 foreach_in_list(ir_instruction
, node
, stage
->ir
) {
1419 ir_variable
*const var
= node
->as_variable();
1421 if (var
== NULL
|| var
->data
.mode
!= io_mode
|| !var
->data
.explicit_location
)
1424 var_slot
= var
->data
.location
- VARYING_SLOT_VAR0
;
1425 if (var_slot
>= 0 && var_slot
< MAX_VARYING
)
1426 slots
|= 1u << var_slot
;
1434 * Assign locations for all variables that are produced in one pipeline stage
1435 * (the "producer") and consumed in the next stage (the "consumer").
1437 * Variables produced by the producer may also be consumed by transform
1440 * \param num_tfeedback_decls is the number of declarations indicating
1441 * variables that may be consumed by transform feedback.
1443 * \param tfeedback_decls is a pointer to an array of tfeedback_decl objects
1444 * representing the result of parsing the strings passed to
1445 * glTransformFeedbackVaryings(). assign_location() will be called for
1446 * each of these objects that matches one of the outputs of the
1449 * When num_tfeedback_decls is nonzero, it is permissible for the consumer to
1450 * be NULL. In this case, varying locations are assigned solely based on the
1451 * requirements of transform feedback.
1454 assign_varying_locations(struct gl_context
*ctx
,
1456 struct gl_shader_program
*prog
,
1457 gl_shader
*producer
, gl_shader
*consumer
,
1458 unsigned num_tfeedback_decls
,
1459 tfeedback_decl
*tfeedback_decls
)
1461 if (ctx
->Const
.DisableVaryingPacking
) {
1462 /* Transform feedback code assumes varyings are packed, so if the driver
1463 * has disabled varying packing, make sure it does not support transform
1466 assert(!ctx
->Extensions
.EXT_transform_feedback
);
1469 /* Tessellation shaders treat inputs and outputs as shared memory and can
1470 * access inputs and outputs of other invocations.
1471 * Therefore, they can't be lowered to temps easily (and definitely not
1474 bool disable_varying_packing
=
1475 ctx
->Const
.DisableVaryingPacking
||
1476 (consumer
&& consumer
->Stage
== MESA_SHADER_TESS_EVAL
) ||
1477 (consumer
&& consumer
->Stage
== MESA_SHADER_TESS_CTRL
) ||
1478 (producer
&& producer
->Stage
== MESA_SHADER_TESS_CTRL
);
1480 varying_matches
matches(disable_varying_packing
,
1481 producer
? producer
->Stage
: (gl_shader_stage
)-1,
1482 consumer
? consumer
->Stage
: (gl_shader_stage
)-1);
1483 hash_table
*tfeedback_candidates
1484 = hash_table_ctor(0, hash_table_string_hash
, hash_table_string_compare
);
1485 hash_table
*consumer_inputs
1486 = hash_table_ctor(0, hash_table_string_hash
, hash_table_string_compare
);
1487 hash_table
*consumer_interface_inputs
1488 = hash_table_ctor(0, hash_table_string_hash
, hash_table_string_compare
);
1489 ir_variable
*consumer_inputs_with_locations
[VARYING_SLOT_TESS_MAX
] = {
1493 unsigned consumer_vertices
= 0;
1494 if (consumer
&& consumer
->Stage
== MESA_SHADER_GEOMETRY
)
1495 consumer_vertices
= prog
->Geom
.VerticesIn
;
1497 /* Operate in a total of four passes.
1499 * 1. Sort inputs / outputs into a canonical order. This is necessary so
1500 * that inputs / outputs of separable shaders will be assigned
1501 * predictable locations regardless of the order in which declarations
1502 * appeared in the shader source.
1504 * 2. Assign locations for any matching inputs and outputs.
1506 * 3. Mark output variables in the producer that do not have locations as
1507 * not being outputs. This lets the optimizer eliminate them.
1509 * 4. Mark input variables in the consumer that do not have locations as
1510 * not being inputs. This lets the optimizer eliminate them.
1513 canonicalize_shader_io(consumer
->ir
, ir_var_shader_in
);
1516 canonicalize_shader_io(producer
->ir
, ir_var_shader_out
);
1519 && !linker::populate_consumer_input_sets(mem_ctx
,
1522 consumer_interface_inputs
,
1523 consumer_inputs_with_locations
)) {
1524 assert(!"populate_consumer_input_sets failed");
1525 hash_table_dtor(tfeedback_candidates
);
1526 hash_table_dtor(consumer_inputs
);
1527 hash_table_dtor(consumer_interface_inputs
);
1532 foreach_in_list(ir_instruction
, node
, producer
->ir
) {
1533 ir_variable
*const output_var
= node
->as_variable();
1535 if ((output_var
== NULL
) ||
1536 (output_var
->data
.mode
!= ir_var_shader_out
))
1539 /* Only geometry shaders can use non-zero streams */
1540 assert(output_var
->data
.stream
== 0 ||
1541 (output_var
->data
.stream
< MAX_VERTEX_STREAMS
&&
1542 producer
->Stage
== MESA_SHADER_GEOMETRY
));
1544 tfeedback_candidate_generator
g(mem_ctx
, tfeedback_candidates
);
1545 g
.process(output_var
);
1547 ir_variable
*const input_var
=
1548 linker::get_matching_input(mem_ctx
, output_var
, consumer_inputs
,
1549 consumer_interface_inputs
,
1550 consumer_inputs_with_locations
);
1552 /* If a matching input variable was found, add this ouptut (and the
1553 * input) to the set. If this is a separable program and there is no
1554 * consumer stage, add the output.
1556 * Always add TCS outputs. They are shared by all invocations
1557 * within a patch and can be used as shared memory.
1559 if (input_var
|| (prog
->SeparateShader
&& consumer
== NULL
) ||
1560 producer
->Type
== GL_TESS_CONTROL_SHADER
) {
1561 matches
.record(output_var
, input_var
);
1564 /* Only stream 0 outputs can be consumed in the next stage */
1565 if (input_var
&& output_var
->data
.stream
!= 0) {
1566 linker_error(prog
, "output %s is assigned to stream=%d but "
1567 "is linked to an input, which requires stream=0",
1568 output_var
->name
, output_var
->data
.stream
);
1573 /* If there's no producer stage, then this must be a separable program.
1574 * For example, we may have a program that has just a fragment shader.
1575 * Later this program will be used with some arbitrary vertex (or
1576 * geometry) shader program. This means that locations must be assigned
1577 * for all the inputs.
1579 foreach_in_list(ir_instruction
, node
, consumer
->ir
) {
1580 ir_variable
*const input_var
= node
->as_variable();
1582 if ((input_var
== NULL
) ||
1583 (input_var
->data
.mode
!= ir_var_shader_in
))
1586 matches
.record(NULL
, input_var
);
1590 for (unsigned i
= 0; i
< num_tfeedback_decls
; ++i
) {
1591 if (!tfeedback_decls
[i
].is_varying())
1594 const tfeedback_candidate
*matched_candidate
1595 = tfeedback_decls
[i
].find_candidate(prog
, tfeedback_candidates
);
1597 if (matched_candidate
== NULL
) {
1598 hash_table_dtor(tfeedback_candidates
);
1599 hash_table_dtor(consumer_inputs
);
1600 hash_table_dtor(consumer_interface_inputs
);
1604 if (matched_candidate
->toplevel_var
->data
.is_unmatched_generic_inout
)
1605 matches
.record(matched_candidate
->toplevel_var
, NULL
);
1608 const uint64_t reserved_slots
=
1609 reserved_varying_slot(producer
, ir_var_shader_out
) |
1610 reserved_varying_slot(consumer
, ir_var_shader_in
);
1612 const unsigned slots_used
= matches
.assign_locations(reserved_slots
,
1613 prog
->SeparateShader
);
1614 matches
.store_locations();
1616 for (unsigned i
= 0; i
< num_tfeedback_decls
; ++i
) {
1617 if (!tfeedback_decls
[i
].is_varying())
1620 if (!tfeedback_decls
[i
].assign_location(ctx
, prog
)) {
1621 hash_table_dtor(tfeedback_candidates
);
1622 hash_table_dtor(consumer_inputs
);
1623 hash_table_dtor(consumer_interface_inputs
);
1628 hash_table_dtor(tfeedback_candidates
);
1629 hash_table_dtor(consumer_inputs
);
1630 hash_table_dtor(consumer_interface_inputs
);
1632 if (consumer
&& producer
) {
1633 foreach_in_list(ir_instruction
, node
, consumer
->ir
) {
1634 ir_variable
*const var
= node
->as_variable();
1636 if (var
&& var
->data
.mode
== ir_var_shader_in
&&
1637 var
->data
.is_unmatched_generic_inout
) {
1640 * On Page 91 (Page 97 of the PDF) of the GLSL ES 1.0 spec:
1642 * If the vertex shader declares but doesn't write to a
1643 * varying and the fragment shader declares and reads it,
1648 linker_warning(prog
, "%s shader varying %s not written "
1650 _mesa_shader_stage_to_string(consumer
->Stage
),
1652 _mesa_shader_stage_to_string(producer
->Stage
));
1653 } else if (prog
->Version
<= 120) {
1654 /* On page 25 (page 31 of the PDF) of the GLSL 1.20 spec:
1656 * Only those varying variables used (i.e. read) in
1657 * the fragment shader executable must be written to
1658 * by the vertex shader executable; declaring
1659 * superfluous varying variables in a vertex shader is
1662 * We interpret this text as meaning that the VS must
1663 * write the variable for the FS to read it. See
1664 * "glsl1-varying read but not written" in piglit.
1666 linker_error(prog
, "%s shader varying %s not written "
1668 _mesa_shader_stage_to_string(consumer
->Stage
),
1670 _mesa_shader_stage_to_string(producer
->Stage
));
1676 if (!disable_varying_packing
) {
1678 lower_packed_varyings(mem_ctx
, slots_used
, ir_var_shader_out
,
1682 lower_packed_varyings(mem_ctx
, slots_used
, ir_var_shader_in
,
1683 consumer_vertices
, consumer
);
1691 check_against_output_limit(struct gl_context
*ctx
,
1692 struct gl_shader_program
*prog
,
1693 gl_shader
*producer
)
1695 unsigned output_vectors
= 0;
1697 foreach_in_list(ir_instruction
, node
, producer
->ir
) {
1698 ir_variable
*const var
= node
->as_variable();
1700 if (var
&& var
->data
.mode
== ir_var_shader_out
&&
1701 var_counts_against_varying_limit(producer
->Stage
, var
)) {
1702 /* outputs for fragment shader can't be doubles */
1703 output_vectors
+= var
->type
->count_attribute_slots(false);
1707 assert(producer
->Stage
!= MESA_SHADER_FRAGMENT
);
1708 unsigned max_output_components
=
1709 ctx
->Const
.Program
[producer
->Stage
].MaxOutputComponents
;
1711 const unsigned output_components
= output_vectors
* 4;
1712 if (output_components
> max_output_components
) {
1713 if (ctx
->API
== API_OPENGLES2
|| prog
->IsES
)
1714 linker_error(prog
, "%s shader uses too many output vectors "
1716 _mesa_shader_stage_to_string(producer
->Stage
),
1718 max_output_components
/ 4);
1720 linker_error(prog
, "%s shader uses too many output components "
1722 _mesa_shader_stage_to_string(producer
->Stage
),
1724 max_output_components
);
1733 check_against_input_limit(struct gl_context
*ctx
,
1734 struct gl_shader_program
*prog
,
1735 gl_shader
*consumer
)
1737 unsigned input_vectors
= 0;
1739 foreach_in_list(ir_instruction
, node
, consumer
->ir
) {
1740 ir_variable
*const var
= node
->as_variable();
1742 if (var
&& var
->data
.mode
== ir_var_shader_in
&&
1743 var_counts_against_varying_limit(consumer
->Stage
, var
)) {
1744 /* vertex inputs aren't varying counted */
1745 input_vectors
+= var
->type
->count_attribute_slots(false);
1749 assert(consumer
->Stage
!= MESA_SHADER_VERTEX
);
1750 unsigned max_input_components
=
1751 ctx
->Const
.Program
[consumer
->Stage
].MaxInputComponents
;
1753 const unsigned input_components
= input_vectors
* 4;
1754 if (input_components
> max_input_components
) {
1755 if (ctx
->API
== API_OPENGLES2
|| prog
->IsES
)
1756 linker_error(prog
, "%s shader uses too many input vectors "
1758 _mesa_shader_stage_to_string(consumer
->Stage
),
1760 max_input_components
/ 4);
1762 linker_error(prog
, "%s shader uses too many input components "
1764 _mesa_shader_stage_to_string(consumer
->Stage
),
1766 max_input_components
);