2 * Copyright © 2013 Intel Corporation
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
27 * State atom for client-programmable geometry shaders, and support code.
30 #include "brw_vec4_gs.h"
31 #include "brw_context.h"
32 #include "brw_vec4_gs_visitor.h"
33 #include "brw_state.h"
37 do_gs_prog(struct brw_context
*brw
,
38 struct gl_shader_program
*prog
,
39 struct brw_geometry_program
*gp
,
40 struct brw_gs_prog_key
*key
)
42 struct brw_stage_state
*stage_state
= &brw
->gs
.base
;
43 struct brw_gs_compile c
;
44 memset(&c
, 0, sizeof(c
));
48 c
.prog_data
.include_primitive_id
=
49 (gp
->program
.Base
.InputsRead
& VARYING_BIT_PRIMITIVE_ID
) != 0;
51 /* Allocate the references to the uniforms that will end up in the
52 * prog_data associated with the compiled program, and which will be freed
55 * Note: param_count needs to be num_uniform_components * 4, since we add
56 * padding around uniform values below vec4 size, so the worst case is that
57 * every uniform is a float which gets padded to the size of a vec4.
59 struct gl_shader
*gs
= prog
->_LinkedShaders
[MESA_SHADER_GEOMETRY
];
60 int param_count
= gs
->num_uniform_components
* 4;
62 /* We also upload clip plane data as uniforms */
63 param_count
+= MAX_CLIP_PLANES
* 4;
65 c
.prog_data
.base
.param
= rzalloc_array(NULL
, const float *, param_count
);
66 c
.prog_data
.base
.pull_param
= rzalloc_array(NULL
, const float *, param_count
);
68 if (gp
->program
.OutputType
== GL_POINTS
) {
69 /* When the output type is points, the geometry shader may output data
70 * to multiple streams, and EndPrimitive() has no effect. So we
71 * configure the hardware to interpret the control data as stream ID.
73 c
.prog_data
.control_data_format
= GEN7_GS_CONTROL_DATA_FORMAT_GSCTL_SID
;
75 /* However, StreamID is not yet supported, so we output zero bits of
76 * control data per vertex.
78 c
.control_data_bits_per_vertex
= 0;
80 /* When the output type is triangle_strip or line_strip, EndPrimitive()
81 * may be used to terminate the current strip and start a new one
82 * (similar to primitive restart), and outputting data to multiple
83 * streams is not supported. So we configure the hardware to interpret
84 * the control data as EndPrimitive information (a.k.a. "cut bits").
86 c
.prog_data
.control_data_format
= GEN7_GS_CONTROL_DATA_FORMAT_GSCTL_CUT
;
88 /* We only need to output control data if the shader actually calls
91 c
.control_data_bits_per_vertex
= gp
->program
.UsesEndPrimitive
? 1 : 0;
93 c
.control_data_header_size_bits
=
94 gp
->program
.VerticesOut
* c
.control_data_bits_per_vertex
;
96 /* 1 HWORD = 32 bytes = 256 bits */
97 c
.prog_data
.control_data_header_size_hwords
=
98 ALIGN(c
.control_data_header_size_bits
, 256) / 256;
100 GLbitfield64 outputs_written
= gp
->program
.Base
.OutputsWritten
;
102 /* In order for legacy clipping to work, we need to populate the clip
103 * distance varying slots whenever clipping is enabled, even if the vertex
104 * shader doesn't write to gl_ClipDistance.
106 if (c
.key
.base
.userclip_active
) {
107 outputs_written
|= BITFIELD64_BIT(VARYING_SLOT_CLIP_DIST0
);
108 outputs_written
|= BITFIELD64_BIT(VARYING_SLOT_CLIP_DIST1
);
111 brw_compute_vue_map(brw
, &c
.prog_data
.base
.vue_map
, outputs_written
);
113 /* Compute the output vertex size.
115 * From the Ivy Bridge PRM, Vol2 Part1 7.2.1.1 STATE_GS - Output Vertex
118 * [0,62] indicating [1,63] 16B units
120 * Specifies the size of each vertex stored in the GS output entry
121 * (following any Control Header data) as a number of 128-bit units
124 * Programming Restrictions: The vertex size must be programmed as a
125 * multiple of 32B units with the following exception: Rendering is
126 * disabled (as per SOL stage state) and the vertex size output by the
129 * If rendering is enabled (as per SOL state) the vertex size must be
130 * programmed as a multiple of 32B units. In other words, the only time
131 * software can program a vertex size with an odd number of 16B units
132 * is when rendering is disabled.
134 * Note: B=bytes in the above text.
136 * It doesn't seem worth the extra trouble to optimize the case where the
137 * vertex size is 16B (especially since this would require special-casing
138 * the GEN assembly that writes to the URB). So we just set the vertex
139 * size to a multiple of 32B (2 vec4's) in all cases.
141 * The maximum output vertex size is 62*16 = 992 bytes (31 hwords). We
142 * budget that as follows:
144 * 512 bytes for varyings (a varying component is 4 bytes and
145 * gl_MaxGeometryOutputComponents = 128)
146 * 16 bytes overhead for VARYING_SLOT_PSIZ (each varying slot is 16
148 * 16 bytes overhead for gl_Position (we allocate it a slot in the VUE
149 * even if it's not used)
150 * 32 bytes overhead for gl_ClipDistance (we allocate it 2 VUE slots
151 * whenever clip planes are enabled, even if the shader doesn't
152 * write to gl_ClipDistance)
153 * 16 bytes overhead since the VUE size must be a multiple of 32 bytes
154 * (see below)--this causes up to 1 VUE slot to be wasted
155 * 400 bytes available for varying packing overhead
157 * Worst-case varying packing overhead is 3/4 of a varying slot (12 bytes)
158 * per interpolation type, so this is plenty.
161 unsigned output_vertex_size_bytes
= c
.prog_data
.base
.vue_map
.num_slots
* 16;
162 assert(output_vertex_size_bytes
<= GEN7_MAX_GS_OUTPUT_VERTEX_SIZE_BYTES
);
163 c
.prog_data
.output_vertex_size_hwords
=
164 ALIGN(output_vertex_size_bytes
, 32) / 32;
166 /* Compute URB entry size. The maximum allowed URB entry size is 32k.
167 * That divides up as follows:
169 * 64 bytes for the control data header (cut indices or StreamID bits)
170 * 4096 bytes for varyings (a varying component is 4 bytes and
171 * gl_MaxGeometryTotalOutputComponents = 1024)
172 * 4096 bytes overhead for VARYING_SLOT_PSIZ (each varying slot is 16
173 * bytes/vertex and gl_MaxGeometryOutputVertices is 256)
174 * 4096 bytes overhead for gl_Position (we allocate it a slot in the VUE
175 * even if it's not used)
176 * 8192 bytes overhead for gl_ClipDistance (we allocate it 2 VUE slots
177 * whenever clip planes are enabled, even if the shader doesn't
178 * write to gl_ClipDistance)
179 * 4096 bytes overhead since the VUE size must be a multiple of 32
180 * bytes (see above)--this causes up to 1 VUE slot to be wasted
181 * 8128 bytes available for varying packing overhead
183 * Worst-case varying packing overhead is 3/4 of a varying slot per
184 * interpolation type, which works out to 3072 bytes, so this would allow
185 * us to accommodate 2 interpolation types without any danger of running
188 * In practice, the risk of running out of URB space is very small, since
189 * the above figures are all worst-case, and most of them scale with the
190 * number of output vertices. So we'll just calculate the amount of space
191 * we need, and if it's too large, fail to compile.
193 unsigned output_size_bytes
=
194 c
.prog_data
.output_vertex_size_hwords
* 32 * gp
->program
.VerticesOut
;
195 output_size_bytes
+= 32 * c
.prog_data
.control_data_header_size_hwords
;
197 assert(output_size_bytes
>= 1);
198 if (output_size_bytes
> GEN7_MAX_GS_URB_ENTRY_SIZE_BYTES
)
201 /* URB entry sizes are stored as a multiple of 64 bytes. */
202 c
.prog_data
.base
.urb_entry_size
= ALIGN(output_size_bytes
, 64) / 64;
204 c
.prog_data
.output_topology
= prim_to_hw_prim
[gp
->program
.OutputType
];
206 brw_compute_vue_map(brw
, &c
.input_vue_map
, c
.key
.input_varyings
);
208 /* GS inputs are read from the VUE 256 bits (2 vec4's) at a time, so we
209 * need to program a URB read length of ceiling(num_slots / 2).
211 c
.prog_data
.base
.urb_read_length
= (c
.input_vue_map
.num_slots
+ 1) / 2;
213 void *mem_ctx
= ralloc_context(NULL
);
214 unsigned program_size
;
215 const unsigned *program
=
216 brw_gs_emit(brw
, prog
, &c
, mem_ctx
, &program_size
);
217 if (program
== NULL
) {
218 ralloc_free(mem_ctx
);
222 /* Scratch space is used for register spilling */
223 if (c
.base
.last_scratch
) {
224 perf_debug("Geometry shader triggered register spilling. "
225 "Try reducing the number of live vec4 values to "
226 "improve performance.\n");
228 c
.prog_data
.base
.total_scratch
229 = brw_get_scratch_size(c
.base
.last_scratch
*REG_SIZE
);
231 brw_get_scratch_bo(brw
, &stage_state
->scratch_bo
,
232 c
.prog_data
.base
.total_scratch
* brw
->max_gs_threads
);
235 brw_upload_cache(&brw
->cache
, BRW_GS_PROG
,
236 &c
.key
, sizeof(c
.key
),
237 program
, program_size
,
238 &c
.prog_data
, sizeof(c
.prog_data
),
239 &stage_state
->prog_offset
, &brw
->gs
.prog_data
);
240 ralloc_free(mem_ctx
);
247 brw_upload_gs_prog(struct brw_context
*brw
)
249 struct gl_context
*ctx
= &brw
->ctx
;
250 struct brw_stage_state
*stage_state
= &brw
->gs
.base
;
251 struct brw_gs_prog_key key
;
252 /* BRW_NEW_GEOMETRY_PROGRAM */
253 struct brw_geometry_program
*gp
=
254 (struct brw_geometry_program
*) brw
->geometry_program
;
257 /* No geometry shader. Vertex data just passes straight through. */
258 if (brw
->state
.dirty
.brw
& BRW_NEW_VUE_MAP_VS
) {
259 brw
->vue_map_geom_out
= brw
->vue_map_vs
;
260 brw
->state
.dirty
.brw
|= BRW_NEW_VUE_MAP_GEOM_OUT
;
265 struct gl_program
*prog
= &gp
->program
.Base
;
267 memset(&key
, 0, sizeof(key
));
269 key
.base
.program_string_id
= gp
->id
;
270 brw_setup_vec4_key_clip_info(brw
, &key
.base
, gp
->program
.UsesClipDistance
);
272 /* _NEW_LIGHT | _NEW_BUFFERS */
273 key
.base
.clamp_vertex_color
= ctx
->Light
._ClampVertexColor
;
276 brw_populate_sampler_prog_key_data(ctx
, prog
, stage_state
->sampler_count
,
279 /* BRW_NEW_VUE_MAP_VS */
280 key
.input_varyings
= brw
->vue_map_vs
.slots_valid
;
282 if (!brw_search_cache(&brw
->cache
, BRW_GS_PROG
,
284 &stage_state
->prog_offset
, &brw
->gs
.prog_data
)) {
285 bool success
= do_gs_prog(brw
, ctx
->Shader
.CurrentGeometryProgram
,
289 if (memcmp(&brw
->vs
.prog_data
->base
.vue_map
, &brw
->vue_map_geom_out
,
290 sizeof(brw
->vue_map_geom_out
)) != 0) {
291 brw
->vue_map_geom_out
= brw
->gs
.prog_data
->base
.vue_map
;
292 brw
->state
.dirty
.brw
|= BRW_NEW_VUE_MAP_GEOM_OUT
;
297 const struct brw_tracked_state brw_gs_prog
= {
299 .mesa
= (_NEW_LIGHT
| _NEW_BUFFERS
| _NEW_TEXTURE
),
300 .brw
= BRW_NEW_GEOMETRY_PROGRAM
| BRW_NEW_VUE_MAP_VS
,
302 .emit
= brw_upload_gs_prog
307 brw_gs_prog_data_compare(const void *in_a
, const void *in_b
)
309 const struct brw_gs_prog_data
*a
= in_a
;
310 const struct brw_gs_prog_data
*b
= in_b
;
312 /* Compare the base vec4 structure. */
313 if (!brw_vec4_prog_data_compare(&a
->base
, &b
->base
))
316 /* Compare the rest of the struct. */
317 const unsigned offset
= sizeof(struct brw_vec4_prog_data
);
318 if (memcmp(((char *) a
) + offset
, ((char *) b
) + offset
,
319 sizeof(struct brw_gs_prog_data
) - offset
)) {
328 brw_gs_prog_data_free(const void *in_prog_data
)
330 const struct brw_gs_prog_data
*prog_data
= in_prog_data
;
332 brw_vec4_prog_data_free(&prog_data
->base
);