loopyt ec5f37821d fix(h20): let the reference backend sync, and stop the reference raising under the guard ... Running end to end surfaced two things the per-kernel A/B could not. The engine wraps the forward pass in `forbid_cuda_sync()`, which sets torch's sync debug mode to "error". The compiled kernels never sync; the torch references do, and not by oversight: * `tile_kernels/torch/cast.py` built `torch.tensor(-1.0, device="cuda")` (and three more like it) for use as a `torch.where` operand. Constructing a device tensor from a Python scalar is a host-to-device copy, so it syncs -- and it is unnecessary, because `torch.where` accepts a plain scalar and passes it to the kernel. Patched via `patch_torch_ref_sync.py` (idempotent, reversible), which is a fix worth having on its own: the same cast raises for any caller that holds the device clean. * `get_mapping_from_psum` reads the expert prefix-sum to the host to compute alignment ranges in Python, and `moe_topk_gate_forward` compacts rows with `nonzero()` and branches on `.any()`. Those cannot be made sync-free without rewriting how the reference addresses, which is the wrong trade for a fallback whose job is being runnable. So each compat module wraps its reference module once and every call through it runs inside `allow_cuda_sync()`. Not done, deliberately: `set_sync_debug_mode("default")` process-wide. That would also stop the guard catching accidental syncs in the compiled path, which is what it is for. Also fixed: my own `bool(force_random.any())` in the gate adapter was itself a sync, outside the reference, so it raised before the adapter could decide anything. End to end now completes: exit=0, all 8 DP ranks agree, coherent answers. It is not token-identical to the compiled path -- 16/16 samples differ, with a control run confirming the harness is deterministic (two cuda runs are bit-identical), so the difference is real. Recorded in the doc as the next thing to attribute rather than papered over.		2026-10-24 19:10:49 +08:00
..
simulate_no_tilelang	feat(h20): make the pure-torch kernel references usable without TileLang	2026-10-22 16:08:46 +08:00
tile_kernels_patch	fix(h20): let the reference backend sync, and stop the reference raising under the guard	2026-10-24 19:10:49 +08:00
ab_cases.py	test(h20): catch a factory that returns nothing before eight ranks do	2026-10-22 14:16:41 +08:00
build_vendor.sh	initial commit	2026-10-20 12:09:42 +08:00
build.sh	initial commit	2026-10-20 12:09:42 +08:00
compare_layers.py	fix(sm90): expand expert scales on the contraction axis only	2026-10-21 16:50:31 +08:00
copy_site_packages.py	feat(h20): make the FlagTree image setup reproducible instead of a shell history	2026-10-22 13:20:03 +08:00
enable_torch_kernel_refs.sh	feat(h20): make the pure-torch kernel references usable without TileLang	2026-10-22 16:08:46 +08:00
flagtree_triton_probe.py	docs(h20): record what a FlagTree/FlagOS image can and cannot do	2026-10-22 10:53:47 +08:00
format_csrc.sh	initial commit	2026-10-20 12:09:42 +08:00
gen_stub.sh	initial commit	2026-10-20 12:09:42 +08:00
h20_ask.py	style(sm90): satisfy ruff and add the missing type annotations	2026-10-21 17:09:08 +08:00
h20_attn_check.py	style(sm90): satisfy ruff and add the missing type annotations	2026-10-21 17:09:08 +08:00
h20_e2e_report.sh	docs(h20): point at the setup script, and let the report script carry its own defaults	2026-10-22 13:20:08 +08:00
h20_engram_check.py	style(sm90): satisfy ruff and add the missing type annotations	2026-10-21 17:09:08 +08:00
h20_expert_weight_check.py	style(sm90): satisfy ruff and add the missing type annotations	2026-10-21 17:09:08 +08:00
h20_index_decode_check.py	test(sm90): rule out the KV cache and the decode indexer	2026-10-21 20:02:19 +08:00
h20_kv_roundtrip.py	test(sm90): rule out the KV cache and the decode indexer	2026-10-21 20:02:19 +08:00
h20_ops_ab.py	test(h20): catch a factory that returns nothing before eight ranks do	2026-10-22 14:16:41 +08:00
h20_philox_check.py	feat(triton): reproduce cuRAND's Philox stream, so the sampler can be ported	2026-10-22 08:37:08 +08:00
h20_quant_check.py	test(sm90): decode FP4 by table lookup in the quant check	2026-10-21 17:15:16 +08:00
h20_real_requant_check.py	style(sm90): satisfy ruff and add the missing type annotations	2026-10-21 17:09:08 +08:00
h20_recipe_probe.py	debug: capture final logits, and keep the profile forward out of the dumps	2026-10-21 17:44:21 +08:00
h20_rng_dump.py	feat(triton): reproduce cuRAND's Philox stream, so the sampler can be ported	2026-10-22 08:37:08 +08:00
h20_smoke_check.py	style(sm90): satisfy ruff and add the missing type annotations	2026-10-21 17:09:08 +08:00
h20_state_check.py	test(h20): check what the model actually says, in a file rather than on the command line	2026-10-22 10:53:01 +08:00
h20_topk_check.py	style(sm90): satisfy ruff and add the missing type annotations	2026-10-21 17:09:08 +08:00
ref_layer_dump.py	debug: capture final logits, and keep the profile forward out of the dumps	2026-10-21 17:44:21 +08:00
ref_next_token.py	debug: per-step decode dumps, and prove the flip is decode-only	2026-10-21 19:07:49 +08:00
setup_flagtree_image.sh	feat(h20): make the FlagTree image setup reproducible instead of a shell history	2026-10-22 13:20:03 +08:00
verify_tile_kernels_patch.py	feat(h20): make the pure-torch kernel references usable without TileLang	2026-10-22 16:08:46 +08:00