/*
* Copyright © 2013 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
/**
* \file brw_vec4_gs.c
*
* State atom for client-programmable geometry shaders, and support code.
*/
#include "brw_gs.h"
#include "brw_context.h"
#include "brw_vec4_gs_visitor.h"
#include "brw_state.h"
#include "brw_ff_gs.h"
bool
brw_codegen_gs_prog(struct brw_context *brw,
struct gl_shader_program *prog,
struct brw_geometry_program *gp,
struct brw_gs_prog_key *key)
{
struct brw_stage_state *stage_state = &brw->gs.base;
struct brw_gs_compile c;
c.key = *key;
c.gp = gp;
c.prog_data.include_primitive_id =
(gp->program.Base.InputsRead & VARYING_BIT_PRIMITIVE_ID) != 0;
c.prog_data.invocations = gp->program.Invocations;
/* Allocate the references to the uniforms that will end up in the
* prog_data associated with the compiled program, and which will be freed
* by the state cache.
*
* Note: param_count needs to be num_uniform_components * 4, since we add
* padding around uniform values below vec4 size, so the worst case is that
* every uniform is a float which gets padded to the size of a vec4.
*/
struct gl_shader *gs = prog->_LinkedShaders[MESA_SHADER_GEOMETRY];
int param_count = gs->num_uniform_components * 4;
/* We also upload clip plane data as uniforms */
param_count += MAX_CLIP_PLANES * 4;
c.prog_data.base.base.param =
rzalloc_array(NULL, const gl_constant_value *, param_count);
c.prog_data.base.base.pull_param =
rzalloc_array(NULL, const gl_constant_value *, param_count);
c.prog_data.base.base.nr_params = param_count;
if (brw->gen >= 7) {
if (gp->program.OutputType == GL_POINTS) {
/* When the output type is points, the geometry shader may output data
* to multiple streams, and EndPrimitive() has no effect. So we
* configure the hardware to interpret the control data as stream ID.
*/
c.prog_data.control_data_format = GEN7_GS_CONTROL_DATA_FORMAT_GSCTL_SID;
/* We only have to emit control bits if we are using streams */
if (prog->Geom.UsesStreams)
c.control_data_bits_per_vertex = 2;
else
c.control_data_bits_per_vertex = 0;
} else {
/* When the output type is triangle_strip or line_strip, EndPrimitive()
* may be used to terminate the current strip and start a new one
* (similar to primitive restart), and outputting data to multiple
* streams is not supported. So we configure the hardware to interpret
* the control data as EndPrimitive information (a.k.a. "cut bits").
*/
c.prog_data.control_data_format = GEN7_GS_CONTROL_DATA_FORMAT_GSCTL_CUT;
/* We only need to output control data if the shader actually calls
* EndPrimitive().
*/
c.control_data_bits_per_vertex = gp->program.UsesEndPrimitive ? 1 : 0;
}
} else {
/* There are no control data bits in gen6. */
c.control_data_bits_per_vertex = 0;
/* If it is using transform feedback, enable it */
if (prog->TransformFeedback.NumVarying)
c.prog_data.gen6_xfb_enabled = true;
else
c.prog_data.gen6_xfb_enabled = false;
}
c.control_data_header_size_bits =
gp->program.VerticesOut * c.control_data_bits_per_vertex;
/* 1 HWORD = 32 bytes = 256 bits */
c.prog_data.control_data_header_size_hwords =
ALIGN(c.control_data_header_size_bits, 256) / 256;
GLbitfield64 outputs_written = gp->program.Base.OutputsWritten;
/* In order for legacy clipping to work, we need to populate the clip
* distance varying slots whenever clipping is enabled, even if the vertex
* shader doesn't write to gl_ClipDistance.
*/
if (c.key.base.userclip_active) {
outputs_written |= BITFIELD64_BIT(VARYING_SLOT_CLIP_DIST0);
outputs_written |= BITFIELD64_BIT(VARYING_SLOT_CLIP_DIST1);
}
brw_compute_vue_map(brw->intelScreen->devinfo,
&c.prog_data.base.vue_map, outputs_written);
/* Compute the output vertex size.
*
* From the Ivy Bridge PRM, Vol2 Part1 7.2.1.1 STATE_GS - Output Vertex
* Size (p168):
*
* [0,62] indicating [1,63] 16B units
*
* Specifies the size of each vertex stored in the GS output entry
* (following any Control Header data) as a number of 128-bit units
* (minus one).
*
* Programming Restrictions: The vertex size must be programmed as a
* multiple of 32B units with the following exception: Rendering is
* disabled (as per SOL stage state) and the vertex size output by the
* GS thread is 16B.
*
* If rendering is enabled (as per SOL state) the vertex size must be
* programmed as a multiple of 32B units. In other words, the only time
* software can program a vertex size with an odd number of 16B units
* is when rendering is disabled.
*
* Note: B=bytes in the above text.
*
* It doesn't seem worth the extra trouble to optimize the case where the
* vertex size is 16B (especially since this would require special-casing
* the GEN assembly that writes to the URB). So we just set the vertex
* size to a multiple of 32B (2 vec4's) in all cases.
*
* The maximum output vertex size is 62*16 = 992 bytes (31 hwords). We
* budget that as follows:
*
* 512 bytes for varyings (a varying component is 4 bytes and
* gl_MaxGeometryOutputComponents = 128)
* 16 bytes overhead for VARYING_SLOT_PSIZ (each varying slot is 16
* bytes)
* 16 bytes overhead for gl_Position (we allocate it a slot in the VUE
* even if it's not used)
* 32 bytes overhead for gl_ClipDistance (we allocate it 2 VUE slots
* whenever clip planes are enabled, even if the shader doesn't
* write to gl_ClipDistance)
* 16 bytes overhead since the VUE size must be a multiple of 32 bytes
* (see below)--this causes up to 1 VUE slot to be wasted
* 400 bytes available for varying packing overhead
*
* Worst-case varying packing overhead is 3/4 of a varying slot (12 bytes)
* per interpolation type, so this is plenty.
*
*/
unsigned output_vertex_size_bytes = c.prog_data.base.vue_map.num_slots * 16;
output_vertex_size_bytes <= GEN7_MAX_GS_OUTPUT_VERTEX_SIZE_BYTES);
c.prog_data.output_vertex_size_hwords =
ALIGN(output_vertex_size_bytes, 32) / 32;
/* Compute URB entry size. The maximum allowed URB entry size is 32k.
* That divides up as follows:
*
* 64 bytes for the control data header (cut indices or StreamID bits)
* 4096 bytes for varyings (a varying component is 4 bytes and
* gl_MaxGeometryTotalOutputComponents = 1024)
* 4096 bytes overhead for VARYING_SLOT_PSIZ (each varying slot is 16
* bytes/vertex and gl_MaxGeometryOutputVertices is 256)
* 4096 bytes overhead for gl_Position (we allocate it a slot in the VUE
* even if it's not used)
* 8192 bytes overhead for gl_ClipDistance (we allocate it 2 VUE slots
* whenever clip planes are enabled, even if the shader doesn't
* write to gl_ClipDistance)
* 4096 bytes overhead since the VUE size must be a multiple of 32
* bytes (see above)--this causes up to 1 VUE slot to be wasted
* 8128 bytes available for varying packing overhead
*
* Worst-case varying packing overhead is 3/4 of a varying slot per
* interpolation type, which works out to 3072 bytes, so this would allow
* us to accommodate 2 interpolation types without any danger of running
* out of URB space.
*
* In practice, the risk of running out of URB space is very small, since
* the above figures are all worst-case, and most of them scale with the
* number of output vertices. So we'll just calculate the amount of space
* we need, and if it's too large, fail to compile.
*
* The above is for gen7+ where we have a single URB entry that will hold
* all the output. In gen6, we will have to allocate URB entries for every
* vertex we emit, so our URB entries only need to be large enough to hold
* a single vertex. Also, gen6 does not have a control data header.
*/
unsigned output_size_bytes;
if (brw->gen >= 7) {
output_size_bytes =
c.prog_data.output_vertex_size_hwords * 32 * gp->program.VerticesOut;
output_size_bytes += 32 * c.prog_data.control_data_header_size_hwords;
} else {
output_size_bytes = c.prog_data.output_vertex_size_hwords * 32;
}
/* Broadwell stores "Vertex Count" as a full 8 DWord (32 byte) URB output,
* which comes before the control header.
*/
if (brw->gen >= 8)
output_size_bytes += 32;
assert(output_size_bytes
>= 1); int max_output_size_bytes = GEN7_MAX_GS_URB_ENTRY_SIZE_BYTES;
if (brw->gen == 6)
max_output_size_bytes = GEN6_MAX_GS_URB_ENTRY_SIZE_BYTES;
if (output_size_bytes > max_output_size_bytes)
return false;
/* URB entry sizes are stored as a multiple of 64 bytes in gen7+ and
* a multiple of 128 bytes in gen6.
*/
if (brw->gen >= 7)
c.prog_data.base.urb_entry_size = ALIGN(output_size_bytes, 64) / 64;
else
c.prog_data.base.urb_entry_size = ALIGN(output_size_bytes, 128) / 128;
c.prog_data.output_topology =
get_hw_prim_for_gl_prim(gp->program.OutputType);
brw_compute_vue_map(brw->intelScreen->devinfo,
&c.input_vue_map, c.key.input_varyings);
/* GS inputs are read from the VUE 256 bits (2 vec4's) at a time, so we
* need to program a URB read length of ceiling(num_slots / 2).
*/
c.prog_data.base.urb_read_length = (c.input_vue_map.num_slots + 1) / 2;
void *mem_ctx = ralloc_context(NULL);
unsigned program_size;
const unsigned *program =
brw_gs_emit(brw, prog, &c, mem_ctx, &program_size);
if (program == NULL) {
ralloc_free(mem_ctx);
return false;
}
/* Scratch space is used for register spilling */
if (c.base.last_scratch) {
perf_debug("Geometry shader triggered register spilling. "
"Try reducing the number of live vec4 values to "
"improve performance.\n");
c.prog_data.base.base.total_scratch
= brw_get_scratch_size(c.base.last_scratch*REG_SIZE);
brw_get_scratch_bo(brw, &stage_state->scratch_bo,
c.prog_data.base.base.total_scratch *
brw->max_gs_threads);
}
brw_upload_cache(&brw->cache, BRW_CACHE_GS_PROG,
&c.key, sizeof(c.key),
program, program_size,
&c.prog_data, sizeof(c.prog_data),
&stage_state->prog_offset, &brw->gs.prog_data);
ralloc_free(mem_ctx);
return true;
}
static bool
brw_gs_state_dirty(struct brw_context *brw)
{
return brw_state_dirty(brw,
_NEW_TEXTURE,
BRW_NEW_GEOMETRY_PROGRAM |
BRW_NEW_TRANSFORM_FEEDBACK |
BRW_NEW_VUE_MAP_VS);
}
static void
brw_gs_populate_key(struct brw_context *brw,
struct brw_gs_prog_key *key)
{
struct gl_context *ctx = &brw->ctx;
struct brw_stage_state *stage_state = &brw->gs.base;
struct brw_geometry_program *gp =
(struct brw_geometry_program *) brw->geometry_program;
struct gl_program *prog = &gp->program.Base;
key->base.program_string_id = gp->id;
brw_setup_vue_key_clip_info(brw, &key->base,
gp->program.Base.UsesClipDistanceOut);
/* _NEW_TEXTURE */
brw_populate_sampler_prog_key_data(ctx, prog, stage_state->sampler_count,
&key->base.tex);
/* BRW_NEW_VUE_MAP_VS */
key->input_varyings = brw->vue_map_vs.slots_valid;
}
void
brw_upload_gs_prog(struct brw_context *brw)
{
struct gl_context *ctx = &brw->ctx;
struct gl_shader_program **current = ctx->_Shader->CurrentProgram;
struct brw_stage_state *stage_state = &brw->gs.base;
struct brw_gs_prog_key key;
/* BRW_NEW_GEOMETRY_PROGRAM */
struct brw_geometry_program *gp =
(struct brw_geometry_program *) brw->geometry_program;
if (!brw_gs_state_dirty(brw))
return;
if (gp == NULL) {
/* No geometry shader. Vertex data just passes straight through. */
if (brw->ctx.NewDriverState & BRW_NEW_VUE_MAP_VS) {
brw->vue_map_geom_out = brw->vue_map_vs;
brw->ctx.NewDriverState |= BRW_NEW_VUE_MAP_GEOM_OUT;
}
if (brw->gen == 6 &&
(brw->ctx.NewDriverState & BRW_NEW_TRANSFORM_FEEDBACK)) {
gen6_brw_upload_ff_gs_prog(brw);
return;
}
/* Other state atoms had better not try to access prog_data, since
* there's no GS program.
*/
brw->gs.prog_data = NULL;
brw->gs.base.prog_data = NULL;
return;
}
brw_gs_populate_key(brw, &key);
if (!brw_search_cache(&brw->cache, BRW_CACHE_GS_PROG,
&key, sizeof(key),
&stage_state->prog_offset, &brw->gs.prog_data)) {
bool success = brw_codegen_gs_prog(brw, current[MESA_SHADER_GEOMETRY],
gp, &key);
(void)success;
}
brw->gs.base.prog_data = &brw->gs.prog_data->base.base;
if (memcmp(&brw
->gs.
prog_data->base.
vue_map, &brw
->vue_map_geom_out
, sizeof(brw->vue_map_geom_out)) != 0) {
brw->vue_map_geom_out = brw->gs.prog_data->base.vue_map;
brw->ctx.NewDriverState |= BRW_NEW_VUE_MAP_GEOM_OUT;
}
}
bool
brw_gs_precompile(struct gl_context *ctx,
struct gl_shader_program *shader_prog,
struct gl_program *prog)
{
struct brw_context *brw = brw_context(ctx);
struct brw_gs_prog_key key;
uint32_t old_prog_offset = brw->gs.base.prog_offset;
struct brw_gs_prog_data *old_prog_data = brw->gs.prog_data;
bool success;
struct gl_geometry_program *gp = (struct gl_geometry_program *) prog;
struct brw_geometry_program *bgp = brw_geometry_program(gp);
brw_vue_setup_prog_key_for_precompile(ctx, &key.base, bgp->id, &gp->Base);
/* Assume that the set of varyings coming in from the vertex shader exactly
* matches what the geometry shader requires.
*/
key.input_varyings = gp->Base.InputsRead;
success = brw_codegen_gs_prog(brw, shader_prog, bgp, &key);
brw->gs.base.prog_offset = old_prog_offset;
brw->gs.prog_data = old_prog_data;
return success;
}
bool
brw_gs_prog_data_compare(const void *in_a, const void *in_b)
{
const struct brw_gs_prog_data *a = in_a;
const struct brw_gs_prog_data *b = in_b;
/* Compare the base structure. */
if (!brw_stage_prog_data_compare(&a->base.base, &b->base.base))
return false;
/* Compare the rest of the struct. */
const unsigned offset = sizeof(struct brw_stage_prog_data);
if (memcmp(((char *) a
) + offset
, ((char *) b
) + offset
, sizeof(struct brw_gs_prog_data) - offset)) {
return false;
}
return true;
}