From cc9ebbb5e770fbec853df4045ad35eeb1b402bf9 Mon Sep 17 00:00:00 2001 From: MechaCat02 Date: Fri, 3 Jul 2026 07:45:11 +0200 Subject: [PATCH] [iterate-4A] docs: handoff for intro-video-done milestone + speed frontier HANDOFF-intro-video-done.md: what to push/copy, the 6 branch commits, build/run, root-cause summary, and the profiled emulator-speed frontier with ranked levers. Co-Authored-By: Claude Opus 4.8 --- HANDOFF-intro-video-done.md | 109 ++++++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) create mode 100644 HANDOFF-intro-video-done.md diff --git a/HANDOFF-intro-video-done.md b/HANDOFF-intro-video-done.md new file mode 100644 index 0000000..aec5065 --- /dev/null +++ b/HANDOFF-intro-video-done.md @@ -0,0 +1,109 @@ +# Handoff — Intro video SOLVED (`iterate-4A/apu-xma-stage1`, tag `intro-video-done`) + +The original frontier — **why `dat/movie/ADV.wmv` never played** vs Xenia Canary — is **solved**. +The intro renders authentically: white SQUARE ENIX logo + cyan glow + red diamonds on a near-black +background, correct color / geometry / luminance, playing reliably. This doc is the handoff for that +state and the newly-opened **emulator-speed** frontier. + +> Method (unchanged): first-divergence vs canary · fix causes not symptoms · NO masking · measure the +> oracle, never infer. Full setup for this branch is in `HANDOFF-iterate-4A-milestone2.md` (FFmpeg dev +> libs, DuckDB tooling, etc.) — read that first on a fresh machine. + +--- + +## 0. What to push / copy for handoff + +**Git (the only repo):** `xenia-rs/`. Branch `iterate-4A/apu-xma-stage1`, **6 commits ahead of origin**. +```bash +cd xenia-rs +git push origin iterate-4A/apu-xma-stage1 # the 6 commits below +git push origin intro-video-done # the annotated milestone tag (-> 5573ac1) +``` +**Not in git (machine-local — copy manually for a full-context handoff):** +- `../CLAUDE.md` — project working instructions (project root is NOT a git repo). +- `~/.claude/projects/-home-fabi-RE---Project-Sylpheed/memory/` — the auto-memory (`MEMORY.md` + index + topic files). This is where the detailed step-by-step history lives. +- Large local artifacts (NOT pushed): the real ISO (`sylpheed.iso` symlink target), `sylpheed.db` + (DuckDB static-analysis DB, ~1h35m to regenerate — see CLAUDE.md), canary build. + +--- + +## 1. Commits on this branch (ahead of origin) + +| Commit | What | +|---|---| +| `645feb8` | ROOT #1 decode-timeout clock (IPM 10k→1M), #1b feeder starvation (incumbent-pick), #2 `k_8` texture decoder | +| `4344152` | re-baseline boot golden 50M→200M after the clock fix | +| `3559c8f` | ROOT #3 host render path — multi-texture YUV, tfetch dest-swizzle, PS const-bank +256 | +| `deb9292` | RectangleList quad completion (fix diagonal seam) | +| `5573ac1` | MULSC/ADDSC/SUBSC scalar-const operand addressing (fix squared-luma) — **tag `intro-video-done`** | +| `2c883e9` | diagnostics snapshot: `XENIA_PROFILE` profiler + probe/tooling (this handoff) | + +Working tree is **clean** — all diagnostics/tooling are now committed in `2c883e9`. + +--- + +## 2. Build & run (see CLAUDE.md for the authoritative version) + +```bash +cd xenia-rs +export CARGO_BUILD_JOBS=4 && cargo build --release # ~8s incremental +# Headless oracle run (threaded GPU, single-thread CPU lockstep): +RUST_LOG=warn ./target/release/xenia-rs exec sylpheed.iso -n 3000000000 +# Watch the movie (windowed): add --ui ; the first on-screen frame is at ~81s WALL +# (mostly boot). Give it >=150s. Boot is DETERMINISTIC; only wall speed varies. +``` +Movie oracles: `sylph-run.sh [runs] [n] [timeout]` (default 180s). Static analysis: `zq.py` over +`sylpheed.db` (DECIMAL bounds, never `0x`). Both are committed at repo root now. + +--- + +## 3. Root-cause summary (the fixes) + +- **#1 clock deadline** — movie handler `sub_821B4968` has a 2000 ms decode-ready timeout; + `INSTRUCTIONS_PER_MS` 10k ran ~320× too fast so a legit 720p decode looked timed-out → abort. + Fixed to 1_000_000 (`state.rs`; `XENIA_INSTR_PER_MS` overrides). +- **#1b feeder starvation** — co-located feeder tid24 lost the equal-priority rotation; + `pick_runnable` now has an incumbent-preference tiebreak (`scheduler.rs`; `XENIA_INCUMBENT_PICK`). +- **#2 `k_8` decoder** — the movie uploads YUV planes as linear `k_8`; added `decode_k8`. +- **#3 host render path** — multi-texture (8 YUV slots), tfetch 12-bit dest-swizzle, PS constant + bank +256 (Xenos splits VS 0..255 / PS 256..511), RectangleList quad synthesis (v3=v0+v2−v1), + and MULSC operand addressing (src3, not src_a/src_b). Details: memory topic file STEPs 88→97. + +--- + +## 4. Open frontier — emulator SPEED (profiled, not yet worked) + +Playback is slow (~14–19 fps). First quantified profile (`XENIA_PROFILE=1`, headless): + +- Effective **~35 MIPS** overall (3 B guest instr / 86 s clean). +- **Interpreter body ~40% @ ~95–102 MIPS**; kernel HLE ~4%; block-cache lookup ~5–6%; + **texture decode 0.3% (cache works — not a bottleneck); present ~0%; no default IPS throttle.** +- The rest is **per-block dispatch + scheduler plumbing** — ~13 instr/block over ~229 M blocks, + each paying fixed prologue/epilogue/lookup/borrow costs. **Overhead-bound, not interpreter-body + bound.** (Note: default run is single-thread lockstep `run_superblock`, confirming the + "serialized single-core" architecture; the console's 6 HW threads are time-sliced onto one host + thread. `--parallel` exists but is not validated for the movie.) + +**Ranked levers:** +1. **Coarsen the execution unit — longer superblock chains** (raise `superblock_budget`). Cheap, + reversible, targets the dominant overhead. ⚠️ chaining is also the scheduling lever (can starve + the movie subsystem — validate against the oracles). *Start here.* +2. **JIT / block-recompiler** — collapses both the interpreter body and per-block dispatch; the real + ceiling (~5–10×), but a multi-week subsystem. +3. **True multi-core** (guest threads on separate host threads) — huge for a 6-thread workload but + riskiest: would invalidate the IPM=1M + incumbent-pick timing fixes that made the video work. + +**Caveat for the next session:** precise remainder attribution needs a sampling profiler +(`perf_event_paranoid=4` blocks perf without sudo here; gdb `ptrace_scope=1` blocks non-descendant +attach). The `XENIA_PROFILE` coarse timers are the current best tool and are now gated zero-cost +when off. + +--- + +## 5. `XENIA_PROFILE` quick reference + +`XENIA_PROFILE=1 ` → periodic snapshots (every 500 M guest instr, or every 500 presents) + +a clean-exit report on stderr. Buckets: interp `step_block`, kernel HLE `call_export`, block +decode/cache `lookup_or_build`, texture decode, host draw, present, and the unaccounted remainder. +Zero-cost when unset (cached `is_on()` gate). Source: `crates/xenia-gpu/src/prof.rs`.