Cycle 3 (MC interpolation) closure: M1'''=100%, R'''=0.067 RED, M4=-19.5%
Third daedalus-fourier kernel — VP9 8-tap regular subpel filter,
horizontal direction, 8-wide output. Multiply-heavy by design to
stress V3D's no-DP4A deficit. Full cycle Phase 1-7 + M4'''.
Phase 5''' second-model review delivered cleanly — caught 1 RED
bug pre-implementation (src_off off-by-3 indexing convention) and
2 YELLOW gaps (assert MUST language, shaderdb filter-LUT gate).
Without the review, M1''' would have failed silently on first run
with cryptic "high-index source pixels wrong" symptoms.
Phase 6 v1 first-light: M1''' 100.0000% bit-exact (65536/65536
blocks across all 16 mx phases). Phase 5''' filter-LUT prediction
materialised exactly: 197 uniforms (gate was 144), 2 threads (down
from cycle-2's 4 due to register pressure).
Performance:
M2''' = 1.413 Mblock/s (707.9 ns/block)
M3''' = 20.997 Mblock/s (NEON baseline phase3)
R''' = 0.067 (RED band — structural mismatch)
shaderdb: 488 inst, 2 threads, 197 uniforms, 25 max-temps, 0 spills
M4''' concurrent matrix (8s windows):
NEON 1-core 14.479 Mblock/s
NEON 4-core 15.248 Mblock/s <- baseline (compute-bound,
not bandwidth-saturated
like cycles 1+2!)
QPU only 1.380 Mblock/s
MIXED NEON-3 + QPU 12.277 Mblock/s <- -19.5% (FAIL gate)
MIXED NEON-4 + QPU 12.158 Mblock/s <- -20.3%
NEW cross-cycle finding (Phase 9 lesson 2): compute-bound CPU
workloads make the QPU-offload story collapse. Cycles 1+2 were
bandwidth-saturated (4-core scaling 0.56-0.82x of 1-core), so
freeing a CPU core via QPU offload added throughput. Cycle 3 MC
is compute-bound (4-core scaling 1.05x of 1-core — near-linear),
no free cycles to free. QPU contribution (0.45 Mblock/s in
contention) doesn't compensate for losing 1 NEON core delivering
~3.8 Mblock/s.
But 30fps@1080p floor: PASS in every config (1.4x to 15.7x
isolation margin). Per project_30fps_floor_is_fine.md, user-facing
test never fails — daily YouTube playback works fine on any CPU/QPU
split.
DEPLOYMENT RECIPE for higgs (cycle 3 confirmed split):
IDCT (k1) -> QPU (R=0.92, +7% mixed, frees CPU core)
LPF (k2) -> QPU (R=0.41, +7% mixed, frees CPU core)
MC (k3) -> CPU (R=0.067, -19.5% mixed — stays on CPU)
Entropy -> CPU (structurally serial)
Mixed-substrate deployment, not "QPU does everything". Realistic for
higgs: entropy + MC on 2-3 ARM cores; IDCT + LPF dispatched to QPU
concurrently; 1-2 ARM cores left for vscode etc.
New artifacts:
- src/v3d_mc_8h.comp — GLSL kernel
- tests/vp9_mc_ref.c — standalone C ref (REGULAR filter
embedded; clean transcription)
- tests/bench_neon_mc.c — M1'''_c + M3''' bench
- tests/bench_v3d_mc.c — M1''' + M2''' bench with contract
asserts + 30fps margin display
- tests/bench_concurrent_mc.c — M4''' pthread bench
- external/ffmpeg-snapshot/libavcodec/aarch64/vp9mc_neon.S (vendored)
- external/ffmpeg-snapshot/libavcodec/vp9_subpel_filters_table.c
(hand-extracted; provides
ff_vp9_subpel_filters symbol
without dragging in full vp9dsp.c)
- docs/k3_mc_phase{1,2,3,4,5,7}.md — full cycle documentation
Memory updates: project_30fps_floor_is_fine.md (user's 30fps target
recalibration), MEMORY.md index updated.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
+53
-1
@@ -55,6 +55,19 @@ set_source_files_properties(${FFASM_LPF_SOURCES} PROPERTIES
|
||||
COMPILE_OPTIONS "${FFASM_FLAGS}"
|
||||
LANGUAGE ASM)
|
||||
|
||||
# Cycle 3 — VP9 MC interpolation NEON source + filter coefficient table
|
||||
# (vendored 2026-05-18). The .c table provides ff_vp9_subpel_filters
|
||||
# symbol which vp9mc_neon.S references via movrel.
|
||||
set(FFASM_MC_SOURCES
|
||||
${FFSNAP}/libavcodec/aarch64/vp9mc_neon.S
|
||||
)
|
||||
set(FFC_MC_SOURCES
|
||||
${FFSNAP}/libavcodec/vp9_subpel_filters_table.c
|
||||
)
|
||||
set_source_files_properties(${FFASM_MC_SOURCES} PROPERTIES
|
||||
COMPILE_OPTIONS "${FFASM_FLAGS}"
|
||||
LANGUAGE ASM)
|
||||
|
||||
# Tell CMake/gas to preprocess .S sources.
|
||||
set_source_files_properties(${FFASM_SOURCES} PROPERTIES
|
||||
COMPILE_OPTIONS "${FFASM_FLAGS}"
|
||||
@@ -76,6 +89,15 @@ add_executable(bench_neon_lpf
|
||||
${FFASM_LPF_SOURCES}
|
||||
)
|
||||
target_compile_options(bench_neon_lpf PRIVATE -O3 -march=armv8-a+simd)
|
||||
|
||||
# Cycle 3 — VP9 MC interpolation NEON baseline.
|
||||
add_executable(bench_neon_mc
|
||||
tests/bench_neon_mc.c
|
||||
tests/vp9_mc_ref.c
|
||||
${FFASM_MC_SOURCES}
|
||||
${FFC_MC_SOURCES}
|
||||
)
|
||||
target_compile_options(bench_neon_mc PRIVATE -O3 -march=armv8-a+simd)
|
||||
# bench_neon_idct doesn't need vulkan/drm — pure CPU baseline.
|
||||
|
||||
# ---- Vulkan dispatch-overhead microbench (next chunk) ----------------------
|
||||
@@ -125,7 +147,18 @@ if (DAEDALUS_BUILD_VULKAN)
|
||||
VERBATIM
|
||||
)
|
||||
|
||||
add_custom_target(daedalus_shaders ALL DEPENDS ${NOOP_SPV} ${IDCT8_SPV} ${LPF_SPV})
|
||||
set(MC_SPV ${CMAKE_BINARY_DIR}/v3d_mc_8h.spv)
|
||||
add_custom_command(
|
||||
OUTPUT ${MC_SPV}
|
||||
COMMAND ${GLSLANG_VALIDATOR} -V --target-env vulkan1.3
|
||||
-o ${MC_SPV}
|
||||
${CMAKE_SOURCE_DIR}/src/v3d_mc_8h.comp
|
||||
DEPENDS ${CMAKE_SOURCE_DIR}/src/v3d_mc_8h.comp
|
||||
COMMENT "glslang: v3d_mc_8h.comp -> v3d_mc_8h.spv"
|
||||
VERBATIM
|
||||
)
|
||||
|
||||
add_custom_target(daedalus_shaders ALL DEPENDS ${NOOP_SPV} ${IDCT8_SPV} ${LPF_SPV} ${MC_SPV})
|
||||
|
||||
# v3d_runner — reusable Vulkan plumbing.
|
||||
add_library(v3d_runner STATIC src/v3d_runner.c)
|
||||
@@ -155,6 +188,15 @@ if (DAEDALUS_BUILD_VULKAN)
|
||||
target_link_libraries(bench_v3d_lpf PRIVATE v3d_runner Vulkan::Vulkan)
|
||||
target_compile_options(bench_v3d_lpf PRIVATE -O2)
|
||||
|
||||
# Cycle 3 — QPU MC bench.
|
||||
add_executable(bench_v3d_mc
|
||||
tests/bench_v3d_mc.c
|
||||
tests/vp9_mc_ref.c
|
||||
)
|
||||
add_dependencies(bench_v3d_mc daedalus_shaders)
|
||||
target_link_libraries(bench_v3d_mc PRIVATE v3d_runner Vulkan::Vulkan)
|
||||
target_compile_options(bench_v3d_mc PRIVATE -O2)
|
||||
|
||||
# M4 — concurrent CPU(NEON) + QPU bench. Links the FFmpeg NEON
|
||||
# snapshot so we can run real NEON kernels on pinned CPU cores
|
||||
# while the QPU runs its dispatch loop concurrently.
|
||||
@@ -174,6 +216,16 @@ if (DAEDALUS_BUILD_VULKAN)
|
||||
add_dependencies(bench_concurrent_lpf daedalus_shaders)
|
||||
target_link_libraries(bench_concurrent_lpf PRIVATE v3d_runner Vulkan::Vulkan pthread)
|
||||
target_compile_options(bench_concurrent_lpf PRIVATE -O3 -march=armv8-a+simd)
|
||||
|
||||
# Cycle 3 M4''' — concurrent MC.
|
||||
add_executable(bench_concurrent_mc
|
||||
tests/bench_concurrent_mc.c
|
||||
${FFASM_MC_SOURCES}
|
||||
${FFC_MC_SOURCES}
|
||||
)
|
||||
add_dependencies(bench_concurrent_mc daedalus_shaders)
|
||||
target_link_libraries(bench_concurrent_mc PRIVATE v3d_runner Vulkan::Vulkan pthread)
|
||||
target_compile_options(bench_concurrent_mc PRIVATE -O3 -march=armv8-a+simd)
|
||||
endif()
|
||||
|
||||
# ---- Summary ----------------------------------------------------------------
|
||||
|
||||
Reference in New Issue
Block a user