Files
daedalus-fourier/CMakeLists.txt
T
marfrit 36eca40ff2 Cycle 2 (LPF) closure: M1''=100%, R''=0.41, M4''=+6.9%, PASS
Phase 4 plan + Phase 5 second-model review (PASS-WITH-REVISIONS:
2 YELLOW contract gaps applied) + Phase 6 v1 implementation +
Phase 7 verification including M4'' concurrent gate.

Phase 5'' review delivered cleanly — no RED bugs (cycle 1 lessons
applied successfully). 2 YELLOW findings baked into phase4 §4:
  - stride >= 4 contract added alongside m.x >= 4 (finding 2)
  - assert(...) in bench made a MUST not a suggestion (finding 4)
  - V3D divergence-cost note: don't restructure to always-execute,
    masked lanes consume clock anyway (finding 3, informational)

Phase 6 v1 first-light hit M1'' 100.0000% bit-exact on first run
(65536/65536 edges) — the cycle-1 v4 patterns (WG=256, 2-per-sg,
uint8_t SSBO, oob early-return discipline) baked in from start
worked as expected.

Performance:

  M2'' = 19.645 Medge/s     (50.9 ns/edge)
  M3'' = 48.285 Medge/s     (NEON baseline from phase3)
  R''  = 0.41               (ORANGE band - doesn't auto-close per
                             cycle-1 calibration adjustment)

shaderdb: 160 inst, **4 threads**, 0 spills, 21 max-temps —
shader is already at the compiler ceiling. No v2/v3/v4 iteration
loop like cycle 1 because there's nothing more to extract from
the compiled shape. The 30x gap between theoretical instruction
throughput and measured wall-clock is divergence-tax + memory
latency, not compile quality.

M4'' concurrent matrix on hertz (8s windows):

  NEON-1 LPF          41.131 Medge/s
  NEON-4 LPF          33.726 Medge/s  <- realistic CPU ceiling
                                          (per-core 7-9; same
                                          bandwidth-saturation as
                                          cycle-1 F1)
  QPU only            14.299 Medge/s
  MIXED NEON-3 + QPU  36.049 Medge/s  <- +6.9% over NEON-4
  MIXED NEON-4 + QPU  31.892 Medge/s  <- -5.4% oversubscribed

The "freed-core" pattern generalizes from IDCT to LPF: NEON-3+QPU
beats pure NEON-4 by ~7% in both cycles. Cycle-2 NEW finding:
**oversubscribed mode hurts for lighter kernels** (LPF -5.4% vs
cycle-1 IDCT +9.4%). Recommendation for higgs deployment hardens
to "always N-1 NEON cores + QPU, never N + QPU".

Phase 9 lessons (in phase7 §"Phase 9 lessons"):
1. Cycle-1 v4-pattern is the v1 starting point (saves 3 iterations)
2. Phase 5 review pays off every cycle
3. R isolation misleading on bandwidth-saturated hardware
4. Oversubscription tax depends on kernel weight
5. shaderdb 4-threads/0-spills = compute not the bottleneck

New artifacts:
- src/v3d_lpf_h_4_8.comp                — GLSL kernel
- tests/bench_v3d_lpf.c                 — M1'' + M2'' harness with
                                          contract asserts + fm/hev
                                          pass-rate instrumentation
- tests/bench_concurrent_lpf.c          — M4'' pthread bench
                                          (mirrors bench_concurrent.c)
- docs/k2_deblock_phase{4,5,7}.md       — plan + review + verification

Project verdict: continue. Cycle 3 candidates: MC interpolation
(multiply-heavy, stress V3D SMUL24), CDEF (AV1-only, different
neighborhood shape), or wd=8/wd=16 LPF variants. User to direct.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-18 12:39:26 +00:00

186 lines
6.6 KiB
CMake

# daedalus-fourier — Phase 3 baseline + (later) Phase 6 implementation.
#
# Builds:
# bench_neon_idct — NEON throughput baseline (Phase 3 M3) +
# bit-exact correctness gate (Phase 1 M1).
# bench_vulkan_dispatch — Vulkan compute dispatch-overhead baseline (M5).
#
# Linkage note: bench_neon_idct statically links the vendored
# FFmpeg n7.1.3 NEON snapshot (LGPL-2.1+); see
# external/ffmpeg-snapshot/PROVENANCE.md.
cmake_minimum_required(VERSION 3.20)
project(daedalus-fourier C ASM)
set(CMAKE_C_STANDARD 11)
set(CMAKE_C_STANDARD_REQUIRED ON)
if (NOT CMAKE_BUILD_TYPE)
set(CMAKE_BUILD_TYPE Release)
endif()
if (NOT CMAKE_SYSTEM_PROCESSOR MATCHES "aarch64")
message(FATAL_ERROR
"daedalus-fourier targets aarch64 (Pi 5 / BCM2712). "
"Cross-compile not yet wired.")
endif()
add_compile_options(-Wall -Wextra -Wno-unused-parameter)
# ---- Vendored FFmpeg snapshot (LGPL-2.1+) -----------------------------------
set(FFSNAP ${CMAKE_SOURCE_DIR}/external/ffmpeg-snapshot)
# Assembly preamble (config.h shim + FFmpeg's asm helpers) used by the
# vendored .S file. -I flags expose:
# - FFSNAP/ so `#include "config.h"` finds our shim
# - FFSNAP/libavcodec/aarch64/ so `#include "neon.S"` finds the helper
# - FFSNAP/ so `#include "libavutil/aarch64/asm.S"`
# resolves against the vendored copy
set(FFASM_FLAGS
-I${FFSNAP}
-I${FFSNAP}/libavcodec/aarch64
-I${FFSNAP}
)
set(FFASM_SOURCES
${FFSNAP}/libavcodec/aarch64/vp9itxfm_neon.S
)
# Cycle 2 — VP9 loop filter NEON source (vendored 2026-05-18).
set(FFASM_LPF_SOURCES
${FFSNAP}/libavcodec/aarch64/vp9lpf_neon.S
)
set_source_files_properties(${FFASM_LPF_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}"
LANGUAGE ASM)
# ---- NEON baseline microbenches --------------------------------------------
add_executable(bench_neon_idct
tests/bench_neon_idct.c
tests/vp9_idct8_ref.c
${FFASM_SOURCES}
)
target_compile_options(bench_neon_idct PRIVATE -O3 -march=armv8-a+simd)
# Cycle 2 — VP9 loop filter NEON baseline.
add_executable(bench_neon_lpf
tests/bench_neon_lpf.c
tests/vp9_lpf_ref.c
${FFASM_LPF_SOURCES}
)
target_compile_options(bench_neon_lpf PRIVATE -O3 -march=armv8-a+simd)
# bench_neon_idct doesn't need vulkan/drm — pure CPU baseline.
# ---- Vulkan dispatch-overhead microbench (next chunk) ----------------------
# Stub: written in a follow-up step. Toggle ON with -DDAEDALUS_BUILD_VULKAN=ON
# once tests/bench_vulkan_dispatch.c exists.
option(DAEDALUS_BUILD_VULKAN "Build Vulkan compute-dispatch microbench" ON)
if (DAEDALUS_BUILD_VULKAN)
find_package(Vulkan REQUIRED)
# Compile GLSL compute shaders to SPIR-V via glslangValidator.
# The binary loads them at runtime from the build dir (cwd-relative).
find_program(GLSLANG_VALIDATOR
NAMES glslangValidator glslang
REQUIRED)
set(NOOP_SPV ${CMAKE_BINARY_DIR}/noop.spv)
add_custom_command(
OUTPUT ${NOOP_SPV}
COMMAND ${GLSLANG_VALIDATOR} -V -o ${NOOP_SPV}
${CMAKE_SOURCE_DIR}/tests/shaders/noop.comp
DEPENDS ${CMAKE_SOURCE_DIR}/tests/shaders/noop.comp
COMMENT "glslang: noop.comp -> noop.spv"
VERBATIM
)
set(IDCT8_SPV ${CMAKE_BINARY_DIR}/v3d_idct8.spv)
add_custom_command(
OUTPUT ${IDCT8_SPV}
COMMAND ${GLSLANG_VALIDATOR} -V --target-env vulkan1.3
-o ${IDCT8_SPV}
${CMAKE_SOURCE_DIR}/src/v3d_idct8.comp
DEPENDS ${CMAKE_SOURCE_DIR}/src/v3d_idct8.comp
COMMENT "glslang: v3d_idct8.comp -> v3d_idct8.spv"
VERBATIM
)
set(LPF_SPV ${CMAKE_BINARY_DIR}/v3d_lpf_h_4_8.spv)
add_custom_command(
OUTPUT ${LPF_SPV}
COMMAND ${GLSLANG_VALIDATOR} -V --target-env vulkan1.3
-o ${LPF_SPV}
${CMAKE_SOURCE_DIR}/src/v3d_lpf_h_4_8.comp
DEPENDS ${CMAKE_SOURCE_DIR}/src/v3d_lpf_h_4_8.comp
COMMENT "glslang: v3d_lpf_h_4_8.comp -> v3d_lpf_h_4_8.spv"
VERBATIM
)
add_custom_target(daedalus_shaders ALL DEPENDS ${NOOP_SPV} ${IDCT8_SPV} ${LPF_SPV})
# v3d_runner — reusable Vulkan plumbing.
add_library(v3d_runner STATIC src/v3d_runner.c)
target_include_directories(v3d_runner PUBLIC src)
target_link_libraries(v3d_runner PUBLIC Vulkan::Vulkan)
target_compile_options(v3d_runner PRIVATE -O2)
add_executable(bench_vulkan_dispatch tests/bench_vulkan_dispatch.c)
add_dependencies(bench_vulkan_dispatch daedalus_shaders)
target_link_libraries(bench_vulkan_dispatch PRIVATE Vulkan::Vulkan)
target_compile_options(bench_vulkan_dispatch PRIVATE -O2)
add_executable(bench_v3d_idct
tests/bench_v3d_idct.c
tests/vp9_idct8_ref.c
)
add_dependencies(bench_v3d_idct daedalus_shaders)
target_link_libraries(bench_v3d_idct PRIVATE v3d_runner Vulkan::Vulkan)
target_compile_options(bench_v3d_idct PRIVATE -O2)
# Cycle 2 — QPU LPF bench.
add_executable(bench_v3d_lpf
tests/bench_v3d_lpf.c
tests/vp9_lpf_ref.c
)
add_dependencies(bench_v3d_lpf daedalus_shaders)
target_link_libraries(bench_v3d_lpf PRIVATE v3d_runner Vulkan::Vulkan)
target_compile_options(bench_v3d_lpf 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.
add_executable(bench_concurrent
tests/bench_concurrent.c
${FFASM_SOURCES}
)
add_dependencies(bench_concurrent daedalus_shaders)
target_link_libraries(bench_concurrent PRIVATE v3d_runner Vulkan::Vulkan pthread)
target_compile_options(bench_concurrent PRIVATE -O3 -march=armv8-a+simd)
# Cycle 2 M4'' — concurrent LPF.
add_executable(bench_concurrent_lpf
tests/bench_concurrent_lpf.c
${FFASM_LPF_SOURCES}
)
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)
endif()
# ---- Summary ----------------------------------------------------------------
message(STATUS "daedalus-fourier build configured for ${CMAKE_SYSTEM_PROCESSOR}")
message(STATUS " FFmpeg snapshot: ${FFSNAP}")
message(STATUS " Build type: ${CMAKE_BUILD_TYPE}")
message(STATUS " Targets: bench_neon_idct"
"$<$<BOOL:${DAEDALUS_BUILD_VULKAN}>:; bench_vulkan_dispatch>")