6bb4355e3d
The publisher splash (title idx0) rendered FLAT in ours while canary samples a texture: ours never decoded the logo's textured pixel shader (E59B2B3D, a `tfetch2D` sprite) even though our guest IM_LOADs the exact same microcode canary does (verified byte-identical against the Wine oracle). The shader was misparsed as flat. Three coupled bugs in the ucode decoder, all off vs canary `gpu/ucode.h`: 1. CF opcode table was off-by-one (`control_flow.rs`): mapped opcode 0→Exec and 1→Exit, but Xenos has 0=kNop, 1=kExec, 2=kExecEnd, 3..6/13..14 the cond-exec variants, 7/8 loop, 9/10 call/return, 11 condjmp, 12 alloc, 15 mark-vs-fetch-done. So a real `kExec` clause was read as a terminal `Exit`, truncating the CF block and dropping every instruction (incl. the `tfetch`) after it. Added Nop/MarkVsFetchDone variants; parse now ends on an END-bit exec clause. 2. exec/loop `address` is an absolute instruction-triple index from shader dword 0, but indexed our post-CF `instructions` slice directly (`ucode/mod.rs`). Rebase addresses by the CF triple count so `address*3` lands on the right instruction. 3. Fetch instruction bitfields were wrong (`ucode/fetch.rs`): `const_index` read from bit 5 (actually `src_reg`) instead of bit 20, and texture `dimension` from dword1 instead of dword2 bit14. The logo's `tfetch ..,tf0` was read as `tf1`, whose empty fetch-constant failed to decode → no texture. Also the `sequence` fetch/ALU bit is bit[0] of each pair, not bit[1] (`shader_metrics.rs`, `translator.rs`, `xenos_interp.wgsl`). Result (--gpu-inline, deterministic 2x): the active PS's `tfetch_slots` now resolves slot 0, the tf0 fetch-constant decodes (fmt K8888), and `gpu.texture.decode` fires (137x at -n 50M; texture_cache_entries 0→1, the only golden field that changed — all draw/swap counts unchanged). The same fixes correct the WGSL uber-shader's fetch/CF walk for the threaded/--ui path. Added a regression test that parses the real E59B2B3D microcode and asserts a tfetch slot is found. Golden re-baselined (texture_cache_entries 0→1). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Sylpheed regression goldens
These JSON files anchor xenia-rs check digest output for Project Sylpheed.
Files
| File | -n | Mode | Captures |
|---|---|---|---|
sylpheed_n2m.json |
2_000_000 | full digest | early boot (swaps=0, no rendering) |
sylpheed_n50m.json |
50_000_000 | stable-digest | first VdSwap pair (swaps=2 post-Phase-A) |
Stable-digest mode
sylpheed_n50m.json is captured with --stable-digest, which omits
timing-sensitive counters: packets (±2–8% lockstep noise from a GPU thread
race), resolves, interrupts_delivered, interrupts_dropped,
texture_decodes. The remaining fields are byte-identical across repeated
lockstep runs at a fixed -n.
sylpheed_n2m.json predates the stable-digest flag and uses full-digest
compare. It still works because at -n 2M the GPU pipeline has not produced any
packets yet — packets=0 is trivially deterministic.
Circularity hazard
Per ORACBUG-001/002/003, these goldens were captured by running the same code
they validate. They detect regression from a known-good snapshot, not
correctness. When a planned fix intentionally moves the digest (e.g. a
shader fix landing draws > 0 for the first time), re-baseline the golden as
a separate commit and reference the audit ID in the message.
Re-baselining
cargo build --release -p xenia-app
target/release/xenia-rs check \
"$SYLPHEED_ISO" \
-n 50000000 \
--stable-digest \
--out crates/xenia-app/tests/golden/sylpheed_n50m.json
Running the goldens
cargo test --release -p xenia-app --test sylpheed_oracles -- --ignored --nocapture
The tests are #[ignore]-gated because each run takes a few seconds, which is
unacceptable in the default cargo test cycle. The ISO path defaults to the
contributor's local ~/RE Project Sylpheed/Project Sylpheed*.iso and can be
overridden via SYLPHEED_ISO=/path/to/sylpheed.iso.
n4b canonical-invocation regression anchor (deferred)
The audit's recommended next sprint also called for a sylpheed_n4b.json
golden capturing the canonical reference invocation
xenia-rs check sylpheed.iso -n 4_000_000_000 --parallel --reservations-table.
This is deferred because:
- The
--parallel --reservations-tablecombination is empirically pathologically slow at -n 100M (>32 min per run per the audit memory). At -n 4B the run cost is many hours, not the single-session-friendly 5–15 min the original plan estimated. - Each phase that intentionally moves rendering counters (C, D, E, F) would need a re-baseline of n4b — a significant time cost compounding over the sprint.
Once the renderer-unblock phases (C+D+E) land and draws > 0 is confirmed at
-n 100M lockstep, an n4b artifact may be captured one-shot and stored under
audit-runs/post-fix/ (not as a test golden) as a manual regression anchor for
the canonical invocation.