OpenHarmony/third_party_mesa3d
2
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

radv: compact MRTs to save PS export memory space

Browse Source 
If there are holes between color outputs (e.g. a shader exports MRT1,
but not MRT0), we can remove the holes by moving higher MRTs lower. The
hardware will remap the MRTs to their correct locations if we remove
holes in SPI_SHADER_COL_FORMAT but not CB_SHADER_MASK. This is good for
performance because the hardware will allocate less space for color
MRTs.

This also allows to remove even more unused color exports because we no
longer need to force previous targets to be non-zero. Only SotTR seems
affected from our fossils db.

fossils-db (NAVI21):
Totals from 859 (0.64% of 134913) affected shaders:
VGPRs: 24328 -> 24216 (-0.46%)
CodeSize: 1433276 -> 1422576 (-0.75%)
Instrs: 255275 -> 253728 (-0.61%)
Latency: 1666836 -> 1661544 (-0.32%)
InvThroughput: 346038 -> 343406 (-0.76%)
Copies: 16520 -> 16506 (-0.08%)
PreSGPRs: 25934 -> 25920 (-0.05%)
PreVGPRs: 19903 -> 19662 (-1.21%)

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5786>
This commit is contained in:
Samuel Pitoiset
2022-08-15 11:59:03 +02:00
committed by Marge Bot
parent 49c7d28b0b
commit 8fcb4aa0eb
3 changed files with 55 additions and 26 deletions
Download Patch File Download Diff File Expand all files Collapse all files

44
src/amd/vulkan/radv_pipeline.c
View File

@@ -533,13 +533,41 @@ format_is_float32(VkFormat format)
desc->channel[channel].type == UTIL_FORMAT_TYPE_FLOAT && desc->channel[channel].size == 32;
}
static unsigned
radv_compact_spi_shader_col_format(const struct radv_shader *ps,
const struct radv_blend_state *blend)
{
unsigned spi_shader_col_format = blend->spi_shader_col_format;
unsigned value = 0, num_mrts = 0;
unsigned i, num_targets;
/* Make sure to clear color attachments without exports because MRT holes are removed during
* compilation for optimal performance.
*/
spi_shader_col_format &= ps->info.ps.colors_written;
/* Compute the number of MRTs. */
num_targets = DIV_ROUND_UP(util_last_bit(spi_shader_col_format), 4);
/* Remove holes in spi_shader_col_format. */
for (i = 0; i < num_targets; i++) {
unsigned spi_format = (spi_shader_col_format >> (i * 4)) & 0xf;
if (spi_format) {
value |= spi_format << (num_mrts * 4);
num_mrts++;
}
}
return value;
}
static void
radv_pipeline_compute_spi_color_formats(const struct radv_graphics_pipeline *pipeline,
struct radv_blend_state *blend,
const struct vk_graphics_pipeline_state *state)
{
unsigned col_format = 0, is_int8 = 0, is_int10 = 0, is_float32 = 0;
unsigned num_targets;
for (unsigned i = 0; i < state->rp->color_attachment_count; ++i) {
unsigned cf;
@@ -572,16 +600,6 @@ radv_pipeline_compute_spi_color_formats(const struct radv_graphics_pipeline *pip
col_format |= V_028714_SPI_SHADER_32_AR;
}
/* If the i-th target format is set, all previous target formats must
* be non-zero to avoid hangs.
*/
num_targets = (util_last_bit(col_format) + 3) / 4;
for (unsigned i = 0; i < num_targets; i++) {
if (!(col_format & (0xfu << (i * 4)))) {
col_format |= V_028714_SPI_SHADER_32_R << (i * 4);
}
}
/* The output for dual source blending should have the same format as
* the first output.
*/
@@ -6030,6 +6048,9 @@ radv_graphics_pipeline_init(struct radv_graphics_pipeline *pipeline, struct radv
if (device->physical_device->rad_info.gfx_level >= GFX10_3)
gfx103_pipeline_init_vrs_state(pipeline, &state);
struct radv_shader *ps = pipeline->base.shaders[MESA_SHADER_FRAGMENT];
blend.spi_shader_col_format = radv_compact_spi_shader_col_format(ps, &blend);
/* Ensure that some export memory is always allocated, for two reasons:
*
* 1) Correctness: The hardware ignores the EXEC mask if no export
@@ -6045,7 +6066,6 @@ radv_graphics_pipeline_init(struct radv_graphics_pipeline *pipeline, struct radv
* color and Z formats to SPI_SHADER_ZERO. The hw will skip export
* instructions if any are present.
*/
struct radv_shader *ps = pipeline->base.shaders[MESA_SHADER_FRAGMENT];
if ((device->physical_device->rad_info.gfx_level <= GFX9 || ps->info.ps.can_discard) &&
!blend.spi_shader_col_format) {
if (!ps->info.ps.writes_z && !ps->info.ps.writes_stencil && !ps->info.ps.writes_sample_mask)