radeonsi: use si_nir_is_output_const_if_tex_is_const

When a blending mode producing "color = src * dst" is used and we
can determine that dst is 1, then the draw call can dropped completely.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10979>
This commit is contained in:
Pierre-Eric Pelloux-Prayer 2021-05-06 15:20:21 +02:00
parent 83250036be
commit b78a38bd02
4 changed files with 80 additions and 0 deletions

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@ -402,6 +402,13 @@ struct si_shader_info {
* fragment shader invocations if flat shading.
*/
bool allow_flat_shading;
/* Optimization: if the texture bound to this texunit has been cleared to 1,
* then the draw can be skipped (see si_draw_vbo_skip_noop). Initially the
* value is 0xff (undetermined) and can be later changed to 0 (= false) or
* texunit + 1.
*/
uint8_t writes_1_if_tex_is_1;
};
/* A shader selector is a gallium CSO and contains shader variants and

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@ -418,6 +418,10 @@ void si_nir_scan_shader(const struct nir_shader *nir, struct si_shader_info *inf
info->color_interpolate_loc[1] = nir->info.fs.color1_sample ? TGSI_INTERPOLATE_LOC_SAMPLE :
nir->info.fs.color1_centroid ? TGSI_INTERPOLATE_LOC_CENTROID :
TGSI_INTERPOLATE_LOC_CENTER;
/* Set an invalid value. Will be determined at draw time if needed when the expected
* conditions are met.
*/
info->writes_1_if_tex_is_1 = nir->info.writes_memory ? 0 : 0xff;
}
info->constbuf0_num_slots = nir->num_uniforms;

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@ -24,6 +24,7 @@
#include "si_build_pm4.h"
#include "si_query.h"
#include "si_shader_internal.h"
#include "sid.h"
#include "util/fast_idiv_by_const.h"
#include "util/format/u_format.h"
@ -445,6 +446,14 @@ static void *si_create_blend_state_mode(struct pipe_context *ctx,
blend->alpha_to_one = state->alpha_to_one;
blend->dual_src_blend = util_blend_state_is_dual(state, 0);
blend->logicop_enable = logicop_enable;
blend->allows_noop_optimization =
state->rt[0].rgb_func == PIPE_BLEND_ADD &&
state->rt[0].alpha_func == PIPE_BLEND_ADD &&
state->rt[0].rgb_src_factor == PIPE_BLENDFACTOR_DST_COLOR &&
state->rt[0].alpha_src_factor == PIPE_BLENDFACTOR_DST_COLOR &&
state->rt[0].rgb_dst_factor == PIPE_BLENDFACTOR_ZERO &&
state->rt[0].alpha_dst_factor == PIPE_BLENDFACTOR_ZERO &&
mode == V_028808_CB_NORMAL;
unsigned num_shader_outputs = state->max_rt + 1; /* estimate */
if (blend->dual_src_blend)
@ -627,6 +636,57 @@ static void *si_create_blend_state(struct pipe_context *ctx, const struct pipe_b
return si_create_blend_state_mode(ctx, state, V_028808_CB_NORMAL);
}
static void si_draw_blend_dst_sampler_noop(struct pipe_context *ctx,
const struct pipe_draw_info *info,
unsigned drawid_offset,
const struct pipe_draw_indirect_info *indirect,
const struct pipe_draw_start_count_bias *draws,
unsigned num_draws) {
struct si_context *sctx = (struct si_context *)ctx;
if (sctx->framebuffer.state.nr_cbufs == 1) {
struct si_shader_selector *sel = sctx->shader.ps.cso;
bool free_nir;
if (unlikely(sel->info.writes_1_if_tex_is_1 == 0xff)) {
struct nir_shader *nir = si_get_nir_shader(sel, NULL, &free_nir);
/* Determine if this fragment shader always writes vec4(1) if a specific texture
* is all 1s.
*/
float in[4] = { 1.0, 1.0, 1.0, 1.0 };
float out[4];
int texunit;
if (si_nir_is_output_const_if_tex_is_const(nir, in, out, &texunit) &&
!memcmp(in, out, 4 * sizeof(float))) {
sel->info.writes_1_if_tex_is_1 = 1 + texunit;
} else {
sel->info.writes_1_if_tex_is_1 = 0;
}
if (free_nir)
ralloc_free(nir);
}
if (sel->info.writes_1_if_tex_is_1 &&
sel->info.writes_1_if_tex_is_1 != 0xff) {
/* Now check if the texture is cleared to 1 */
int unit = sctx->shader.ps.cso->info.writes_1_if_tex_is_1 - 1;
struct si_samplers *samp = &sctx->samplers[PIPE_SHADER_FRAGMENT];
if ((1u << unit) & samp->enabled_mask) {
struct si_texture* tex = (struct si_texture*) samp->views[unit]->texture;
if (tex->is_depth &&
tex->depth_cleared_level_mask & BITFIELD_BIT(samp->views[unit]->u.tex.first_level) &&
tex->depth_clear_value[0] == 1) {
return;
}
/* TODO: handle color textures */
}
}
}
sctx->real_draw_vbo(ctx, info, drawid_offset, indirect, draws, num_draws);
}
static void si_bind_blend_state(struct pipe_context *ctx, void *state)
{
struct si_context *sctx = (struct si_context *)ctx;
@ -664,6 +724,14 @@ static void si_bind_blend_state(struct pipe_context *ctx, void *state)
old_blend->commutative_4bit != blend->commutative_4bit ||
old_blend->logicop_enable != blend->logicop_enable)))
si_mark_atom_dirty(sctx, &sctx->atoms.s.msaa_config);
if (likely(!radeon_uses_secure_bos(sctx->ws))) {
if (unlikely(blend->allows_noop_optimization)) {
si_install_draw_wrapper(sctx, si_draw_blend_dst_sampler_noop);
} else {
si_install_draw_wrapper(sctx, NULL);
}
}
}
static void si_delete_blend_state(struct pipe_context *ctx, void *state)

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@ -65,6 +65,7 @@ struct si_state_blend {
bool alpha_to_one : 1;
bool dual_src_blend : 1;
bool logicop_enable : 1;
bool allows_noop_optimization : 1;
};
struct si_state_rasterizer {