fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2026-04-22 16:10:36 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

panfrost: Optimize pan_afbc_payload_layout_packed() for AArch64

Browse source 
Payload size retrieval can greatly benefit from using SIMD to sum up
the 16 6-bit packed sizes. This commit proposes an optimized version
using Arm A64 NEON intrinsics. This was measured on a Rock 5B to be ~2
times faster than the original.

Signed-off-by: Loïc Molinari <loic.molinari@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Mary Guillemard <mary.guillemard@collabora.com>
Acked-by: Eric R. Smith <eric.smith@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35001>
This commit is contained in:
Loïc Molinari 2025-07-03 08:29:45 +02:00 • committed by Marge Bot
parent a9a3ee3719
commit 5f5b8b1db3
1 changed files with 82 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

85
src/panfrost/lib/pan_afbc.c
View file

@ -6,7 +6,12 @@
#include "pan_afbc.h"
#include "util/perf/cpu_trace.h"
#include "util/detect_arch.h"
#if DETECT_ARCH_AARCH64
#include <arm_neon.h>
/* Arm A64 NEON intrinsics version. */
uint32_t
pan_afbc_payload_layout_packed(unsigned arch,
const struct pan_afbc_headerblock *headers,
@ -16,14 +21,86 @@ pan_afbc_payload_layout_packed(unsigned arch,
{
MESA_TRACE_FUNC();
/* XXX: It might be faster to copy the header from non-cacheable memory
* into a cacheline sized chunk in cacheable memory in order to avoid too
* many uncached transactions. Not sure though, so it needs testing. */
uint32_t uncompressed_size =
pan_afbc_payload_uncompressed_size(format, modifier);
uint32_t body_size = 0;
alignas(16) static const uint8_t idx0[16] =
{ 4, 5, 6, ~0, 7, 8, 9, ~0, 10, 11, 12, ~0, 13, 14, 15, ~0 };
alignas(16) static const uint8_t idx1[16] =
{ 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60 };
alignas(16) static const uint8_t mask[16] =
{ 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63 };
alignas(16) static const uint8_t ones[16] =
{ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 };
uint8x16_t vidx0 = vld1q_u8(idx0);
uint8x16_t vidx1 = vld1q_u8(idx1);
uint8x16_t vmask = vld1q_u8(mask);
uint8x16_t vones = vld1q_u8(ones);
for (uint32_t i = 0; i < nr_blocks; ++i) {
uint32_t payload_size = 0;
/* Skip sum if the 1st subblock is 0 (solid color encoding). */
if (arch < 7 || headers[i].payload.subblock_sizes[0] & 0x3f) {
uint8x16_t vhdr = vld1q_u8((uint8_t *)&headers[i]);
/* Dispatch 6-bit packed 16 subblock sizes into 8-bit vector. */
uint8x16_t v0 = vqtbl1q_u8(vhdr, vidx0);
uint8x16_t v1 = vreinterpretq_u8_u32(
vshrq_n_u32(vreinterpretq_u32_u8(v0), 6));
uint8x16_t v2 = vreinterpretq_u8_u32(
vshrq_n_u32(vreinterpretq_u32_u8(v0), 12));
uint8x16_t v3 = vreinterpretq_u8_u32(
vshrq_n_u32(vreinterpretq_u32_u8(v0), 18));
uint8x16x4_t vtbl = {{ v0, v1, v2, v3 }};
v0 = vqtbl4q_u8(vtbl, vidx1);
v0 = vandq_u8(v0, vmask);
/* Sum across vector. */
payload_size = vaddlvq_u8(v0);
/* Number of subblocks of size 1. */
v0 = vceqq_u8(v0, vones);
v0 = vandq_u8(v0, vones);
uint32_t nr_ones = vaddvq_u8(v0);
/* Payload size already stores subblocks of size 1. Fix-up the sum
* using the number of such subblocks. */
payload_size += nr_ones * (uncompressed_size - 1);
payload_size = ALIGN_POT(payload_size, 16);
}
layout[i].size = payload_size;
layout[i].offset = body_size;
body_size += payload_size;
}
return body_size;
}
#else
/* Generic version. */
uint32_t
pan_afbc_payload_layout_packed(unsigned arch,
const struct pan_afbc_headerblock *headers,
struct pan_afbc_payload_extent *layout,
uint32_t nr_blocks, enum pipe_format format,
uint64_t modifier)
{
MESA_TRACE_FUNC();
uint32_t uncompressed_size =
pan_afbc_payload_uncompressed_size(format, modifier);
uint32_t body_size = 0;
/* XXX: It might be faster to copy the header from non-cacheable memory
* into a cacheline sized chunk in cacheable memory in order to avoid too
* many uncached transactions. Not sure though, so it needs testing. */
for (uint32_t i = 0; i < nr_blocks; i++) {
uint32_t payload_size =
pan_afbc_payload_size(arch, headers[i], uncompressed_size);
@ -34,3 +111,5 @@ pan_afbc_payload_layout_packed(unsigned arch,
return body_size;
}
#endif