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ADR-0852: Wire speed_chroma_hip and speed_temporal_hip into HIP Build and Dispatch

  • Status: Accepted
  • Date: 2026-05-29
  • Deciders: lusoris
  • Tags: hip, build, speed, feature, gpu, fork-local

Context

ADR-0567 landed real on-device GPU kernels for speed_chroma and speed_temporal on all four backends (CUDA, SYCL, HIP, Vulkan). The HIP half produced three files:

  • core/src/feature/hip/speed/speed_score.hip — five extern "C" kernels
  • core/src/feature/hip/speed_chroma_hip.c — host wrapper, vmaf_fex_speed_chroma_hip
  • core/src/feature/hip/speed_temporal_hip.c — host wrapper, vmaf_fex_speed_temporal_hip

All three files were committed but none were wired into the build system or the feature extractor registry. The hip_kernel_sources meson dict in core/src/meson.build had no speed_score entry, core/src/hip/meson.build had no entries for the two .c wrappers, and core/src/feature/feature_extractor.c had no extern declarations or dispatch-table entries for the two extractors. This left the SpEED HIP path unreachable regardless of build flags.

Decision

We add the three missing wiring entries (one in each of the three files listed above). No implementation changes are made — only build-system and registry connections. The scaffold posture is preserved: without enable_hipcc=true both extractors' init() returns -ENOSYS, matching every prior HIP consumer's contract.

Alternatives considered

Option Pros Cons Why not chosen
Wire all three simultaneously (chosen) Closes the gap atomically; consistent with ADR-0533 pattern Slightly larger changeset than wiring only one side Wiring only host wrappers without the kernel blob gives a guaranteed -ENOSYS on hipModuleLoadData — no user benefit
Add a weak HSACO stub and defer kernel wiring Keeps link green, mirrors the pre-ADR-0539 ADM pattern Users get -ENOSYS on the kernel load, same as without the stub The real kernel source already exists; there is no reason to defer it

Consequences

  • Positive: speed_chroma_hip and speed_temporal_hip are now reachable via vmaf_get_feature_extractor_by_name; with enable_hipcc=true they run real on-device kernels per ADR-0567.
  • Negative: none — the implementation was already reviewed as part of ADR-0567.
  • Neutral / follow-ups: ADR-0214 cross-backend ULP gate (places=4 vs CPU reference) should be run once a ROCm device is available in CI.

References

  • ADR-0567 (0567-speed-chroma-temporal-real-gpu.md) — original implementation.
  • ADR-0533 (0533-hip-extractor-registration-sweep.md) — HIP extractor wiring pattern.
  • ADR-0539 (0539-integer-adm-hip-kernels.md) — prior art for hip_kernel_sources.
  • core/src/feature/hip/AGENTS.md — hip_hsaco_stubs.c fallback pattern.