Windows-dev: grouped quantization + mixed precision + expert budget + download tool

Consolidates all experiment branches into one Windows-dev branch:

1. Group-scaled int4 (fmt=4, gs=128) — glm.c
   - QT struct: added gs field
   - matmul_i4_grouped: AVX2 kernel, verified to 3e-08 vs f32
   - Format detection: auto-detects from .qs scale array size
   - expert_load: both mmap and slab+pread paths handle fmt=4
   - qt_bytes: fmt=4 case added

2. Per-tensor-type mixed precision — convert_fp8_to_int4.py
   - Split classify() into sh/o/kvb/attn/dmlp sub-types
   - New args: --shared-bits, --o-bits, --kvb-bits, --attn-bits, --dmlp-bits
   - Plan: shared expert + o_proj + kv_b_proj at int8, rest grouped int4
   - Only +5.3 GB RAM vs +0 for pure int4

3. EXPERT_BUDGET (miss-aware) — glm.c
   - Caps distinct experts per layer across batch-union
   - Always keeps cache hits, only drops misses
   - Up to 1.8x faster decode on low-RAM hosts

4. Two-step shared-expert prediction (PILOT_TWO) — glm.c
   - la_predict kind==2 + pilot_prefetch integration
   - +3.1% recall over baseline PILOT

5. FP8 download tool — download_fp8.py
   - ModelScope + HuggingFace dual-source
   - Parallel shard download with stall recovery

6. Tiny model generation — make_glm_oracle.py
   - Generated and tested locally for pipeline validation

c/tools/make_glm_bench_model.py

@@ -3,15 +3,27 @@
 This is not a useful language model. It preserves the real glm_moe_dsa data
 flow while remaining small enough to generate locally and run repeated CPU/CUDA
 A/B tests without downloading the 379 GB checkpoint.
+
+With --fp8 the weights are written as FP8 e4m3 + 128x128 block scale_inv, in the
+SAME layout as the real GLM-5.2-FP8 checkpoint, so convert_fp8_to_int4.py can
+exercise its FP8->int4 dequant path on a local fixture (its dims are 128-friendly,
+so this is also the right fixture for --group-size 128 testing):
+
+  python tools/make_glm_bench_model.py --fp8 --output glm_bench_fp8
+  python tools/convert_fp8_to_int4.py --indir glm_bench_fp8 --outdir glm_bench_i4 --ebits 4 --group-size 128
 """
 
 import argparse
 import json
+import sys
 from pathlib import Path
 
 import torch
 from transformers import GlmMoeDsaConfig, GlmMoeDsaForCausalLM
 
+sys.path.insert(0, str(Path(__file__).resolve().parent))   # importa glm_fp8_emit se lanciato da c/
+from glm_fp8_emit import save_fp8_safetensors
+
 
 def build_config() -> GlmMoeDsaConfig:
     return GlmMoeDsaConfig(
@@ -51,6 +63,9 @@ def main() -> None:
     parser.add_argument("--output", default="glm_bench_medium")
     parser.add_argument("--device", default="cuda" if torch.cuda.is_available() else "cpu")
     parser.add_argument("--seed", type=int, default=1234)
+    parser.add_argument("--fp8", action="store_true",
+                        help="write weights as FP8 e4m3 + 128x128 block scale_inv (same layout as "
+                             "GLM-5.2-FP8) instead of bf16, so convert_fp8_to_int4.py can dequant+requant")
     args = parser.parse_args()
 
     torch.manual_seed(args.seed)
@@ -70,7 +85,16 @@ def main() -> None:
     output = Path(args.output)
     output.mkdir(parents=True, exist_ok=True)
     params = sum(p.numel() for p in model.parameters())
-    model.save_pretrained(output, safe_serialization=True, max_shard_size="4GB")
+    if args.fp8:
+        n_fp8, n_tot = save_fp8_safetensors(model.state_dict(), output / "model.safetensors")
+        # save_pretrained scrive config.json; nel path FP8 lo bypassiamo, quindi lo scriviamo
+        # a mano (serve al converter e al motore C). EN: save_pretrained writes config.json;
+        # the FP8 path bypasses it, so write it manually (converter + C engine need it).
+        (output / "config.json").write_text(json.dumps(cfg.to_dict()))
+        print(f"saved FP8: {n_fp8} e4m3 tensors (+{n_tot - n_fp8} scale_inv sidecars / f32) "
+              f"-> {output / 'model.safetensors'}")
+    else:
+        model.save_pretrained(output, safe_serialization=True, max_shard_size="4GB")
 
     model.to(args.device)
     prompt = [3, 14, 159, 26, 53, 58, 200, 11, 77, 240, 5, 99]
@@ -89,6 +113,7 @@ def main() -> None:
         "seed": args.seed,
         "parameters": params,
         "parameters_billions": round(params / 1e9, 4),
+        "format": "fp8-e4m3-128" if args.fp8 else "bf16",
         "purpose": "backend benchmark fixture; random weights, not a language model",
     }
     (output / "bench_manifest.json").write_text(json.dumps(manifest, indent=2))

c/tools/make_glm_oracle.py

@@ -3,10 +3,34 @@ Architettura vera (MLA + DSA indexer + router sigmoid/noaux_tc + shared expert),
 dimensioni minuscole. Salva pesi+config in c/glm_tiny/ e un riferimento greedy in
 c/ref_glm.json. seq corta (<= index_topk) cosi' il DSA seleziona tutte le key e
 l'attenzione coincide con la MLA densa: il motore C puo' validare senza implementare
-l'indexer sparso."""
-import json, torch
+l'indexer sparso.
+
+--fp8: salva i pesi come FP8 e4m3 + scale a blocchi 128x128 (layout del checkpoint reale
+GLM-5.2-FP8) invece di bf16, cosi' convert_fp8_to_int4.py puo' esercitare il path FP8->int4
+su un modello minuscolo. PRIMA di calcolare ref_glm.json fa il round-trip dei pesi per FP8
+(quant->dequant, copy_ nel modello): cosi' il riferimento riflette ESATTAMENTE il modello
+FP8 che il converter legge, non il modello bf16 a precisione piena. Default: bf16 (oracolo
+originale invariato).
+EN: --fp8 writes FP8 e4m3 + 128x128 block scale_inv (real GLM-5.2-FP8 layout) instead of bf16,
+EN: so convert_fp8_to_int4.py can run its FP8->int4 path on a tiny model. ref_glm.json is
+EN: computed AFTER the FP8 round-trip, so the reference matches exactly what the converter
+EN: ingests. Default: bf16 (original oracle unchanged)."""
+import json, sys, argparse
+from pathlib import Path
+import torch
 from transformers import GlmMoeDsaConfig, GlmMoeDsaForCausalLM
 
+sys.path.insert(0, str(Path(__file__).resolve().parent))   # importa glm_fp8_emit se lanciato da c/
+from glm_fp8_emit import (fp8_block_quantize, fp8_block_dequantize, keep_f32,
+                          save_fp8_safetensors)
+
+ap = argparse.ArgumentParser()
+ap.add_argument("--fp8", action="store_true",
+                help="salva in FP8 e4m3 + 128x128 block scale_inv (layout GLM-5.2-FP8) e "
+                     "calcola ref_glm.json sul modello dopo il round-trip FP8. "
+                     "EN: write FP8 e4m3 + block scale_inv, ref computed on FP8-rounded model")
+args = ap.parse_args()
+
 torch.manual_seed(1234)
 
 cfg = GlmMoeDsaConfig(
@@ -53,6 +77,18 @@ with torch.no_grad():
             layer.mlp.gate.e_score_correction_bias.copy_(
                 torch.linspace(-0.1, 0.1, cfg.n_routed_experts))
 
+# --fp8: round-trip dei pesi quantizzabili per FP8 PRIMA di calcolare il riferimento,
+# cosi' ref_glm.json riflette esattamente il modello FP8 che il converter leggera'.
+# Norme/router/bias (keep_f32) restano a precisione piena. EN: --fp8: round-trip quantizable
+# weights through FP8 before computing the reference, so ref_glm.json matches the FP8 model.
+if args.fp8:
+    with torch.no_grad():
+        for n, p in model.named_parameters():
+            if keep_f32(n, p) or p.dim() < 2:
+                continue
+            q, s = fp8_block_quantize(p)
+            p.copy_(fp8_block_dequantize(q, s))
+
 print("=== state_dict tensors (names used by the C loader) ===")
 for n, p in model.state_dict().items():
     print(f"  {n:60s} {tuple(p.shape)}")
@@ -73,7 +109,13 @@ with torch.no_grad():
 tf_pred = lg.argmax(-1).tolist()
 print("tf_pred:", tf_pred)
 
-model.save_pretrained("glm_tiny", safe_serialization=True)
+if args.fp8:
+    n_fp8, n_tot = save_fp8_safetensors(model.state_dict(), "glm_tiny/model.safetensors")
+    print(f"\nsaved FP8: {n_fp8} e4m3 tensors (+{n_tot - n_fp8} scale_inv sidecars / f32) "
+          f"-> glm_tiny/model.safetensors")
+else:
+    model.save_pretrained("glm_tiny", safe_serialization=True)
 json.dump(cfg.to_dict(), open("glm_tiny/config.json", "w"))
 json.dump({"prompt_ids": prompt, "full_ids": full, "tf_pred": tf_pred}, open("ref_glm.json", "w"))
-print("\nsaved: glm_tiny/ (weights + config) and ref_glm.json")
+print("saved: glm_tiny/ (weights + config) and ref_glm.json"
+      + (" [fp8]" if args.fp8 else ""))