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Gemma 4 31B selected-logit splice, lane by lane

Recorded Doppler reference, live in-browser CSL tail, hash-bound receipt. The hardware lane shows what's publishable today.

pinned to doe@…
model gemma-4-31b-it-text-q4k-ehf16-af16
topK 32 · prompt tokens 7
PROMPT
01 · REFERENCE RECORDED · DOPPLER WEBGPU

Doppler WebGPU reference

Real Gemma 4 31B af16 prefill, last layer post-FFN state, tied lm-head logits. Captured from the frozen reference fixture; sha256-bound.

fixture
frozen at
top-1 token
top-1 logit
top-2 logit
top-1 vs top-2
handoff tensor
recorded sha256
browser sha256
computing…
verification
computing…
passes to 02 · HANDOFF loading…
02 · HANDOFF LIVE · BROWSER HASH

Activation + weight chunks, byte-bound

Per-chunk activation (post-RMSNorm) and lm-head weight slice. Browser recomputes sha256 over each shipped .npy and verifies against the recorded splice receipt.

chunks
6 chunks · 5376 hidden / 32 PE width
per-chunk dtype
activation f16 · weight f16 · output f32
verification
computing…
passes to 03 · CSL TAIL
03 · CSL TAIL DETECTING BACKEND

Live selected lm_head GEMV in your browser

Browser runs the chunked f16 dot product over the same activation + weight bytes the CSL run consumed (post-RMSNorm activations from the splice path). The final_norm_f16 step ran in the recorded splice; its CSL source is shown below for visibility, but only the lm_head_prefill GEMV executes live here.

live kernel
lm_head_prefill · selected token only
recorded chain
final_norm_f16 → lm_head_prefill → softcap (full chain in receipt)
backend
per-chunk math
1024 × f16·f16 → f32 accumulate
raw logit
softcapped
vs Doppler
Authored CSL source (visible kernel lowering)
passes to 04 · RECEIPT
04 · RECEIPT

Splice receipt, schema-bound

Comparison mode: argmax_decision_bound. Top-token decision is preserved; strict logit tolerance is recorded separately.

verdict
argmax stable
CSL argmax
reference argmax
max logit |Δ|
strict tolerance
decision margin
SCOPE
NOT WHAT
hardware lane: simulator ceiling at memcpy_d2h_start; CS-3 receipt pending