daedalus-fourier/CMakeLists.txt

# 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
)

# Tell CMake/gas to preprocess .S sources.
set_source_files_properties(${FFASM_SOURCES} PROPERTIES
    COMPILE_OPTIONS "${FFASM_FLAGS}"
    LANGUAGE ASM)

# ---- NEON baseline microbench ----------------------------------------------

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)
# 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
    )
    add_custom_target(daedalus_shaders ALL DEPENDS ${NOOP_SPV} ${IDCT8_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)

    # 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)
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>")