Npu decode funcall gating#254
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…layer-embedding archs On NPU, the decode (1-token) model compiles the non-repeated blocks as NPUW "funcall-everywhere" subgraphs. For gemma3/4-style architectures those blocks carry the per-layer input embedding (inp_per_layer / per_layer_proj), so each one pays a per-call function prologue (tensor bind + closure unpack) on every decoded token. At batch-1 decode this per-call overhead dominates and makes decode ~8x slower than it should be (gemma4 E2B Q4_K_M: ~1.6 -> ~13 t/s). Fix: give the decode model its own compile config (compile_config_decode) and, for archs that carry a per-layer input embedding, set NPUW_FUNCALL_FOR_ALL=NO for the decode model only. Prefill is unchanged (funcalls there are amortized over the whole prompt). The arch is detected via a per_layer tensor in the graph (ModelParams::has_per_layer_embd); other archs and CPU/GPU are unaffected. Verified no change on Llama-3.2-1B (no per-layer embedding). Adds optional env overrides for experimentation: GGML_OPENVINO_NPUW_FOLD / _FUNCALL_FOR_ALL (both prefill+decode) GGML_OPENVINO_DECODE_NPUW_FOLD / _FUNCALL_FOR_ALL (decode only; precedence)
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openvino: NPU decode fix for gemma3/4 — disable NPUW funcall for per-layer-embedding archs
On NPU, the decode (1-token) model wraps its non-repeated blocks as NPUW funcall
subgraphs. For gemma3/4-style architectures those blocks hold the per-layer input
embedding (
inp_per_layer/per_layer_proj), so each pays a per-call functionprologue (tensor bind + closure unpack) on every decoded token. At batch-1 decode
this overhead dominates.
Fix: the decode model gets its own compile config, and for archs carrying a
per-layer input embedding we set
NPUW_FUNCALL_FOR_ALL=NOfor decode only.Prefill is unchanged; other archs and CPU/GPU are unaffected. Arch detected via a
per_layertensor in the graph (ModelParams::has_per_layer_embd).Results (NPU, c=1024, decode steady-state):
Trade-off: decode-model compile time rises for gated archs (paid once per
process); prefill and CPU/GPU are unaffected.
Adds optional env overrides for experimentation:
GGML_OPENVINO_[DECODE_]NPUW_FOLD/_FUNCALL_FOR_ALL.