Add active-MoE AutoQuant cost accounting

Signed-off-by: weimingc <17592131+meenchen@users.noreply.github.com>

Author: meenchen

examples/llm_ptq/hf_ptq.py

@@ -382,9 +382,18 @@ def forward_step(model, batch):
             f"Invalid auto_quantize_method: {auto_quantize_method}. Must be 'gradient' or 'kl_div'"
         )
 
+    auto_quantize_constraints = {
+        "effective_bits": args.auto_quantize_bits,
+        "cost_model": args.auto_quantize_cost_model,
+    }
+    if args.auto_quantize_active_moe_expert_ratio is not None:
+        auto_quantize_constraints["cost"] = {
+            "active_moe_expert_ratio": args.auto_quantize_active_moe_expert_ratio
+        }
+
     language_model, _ = mtq.auto_quantize(
         language_model,
-        constraints={"effective_bits": args.auto_quantize_bits},
+        constraints=auto_quantize_constraints,
         data_loader=calib_dataloader,
         forward_step=forward_step,
         loss_func=loss_func,  # Only used for gradient-based method
@@ -1401,6 +1410,27 @@ def parse_args() -> argparse.Namespace:
             "(sensitivity scores, costs, etc.). Only used when auto_quantize_bits is specified."
         ),
     )
+    parser.add_argument(
+        "--auto_quantize_cost_model",
+        type=str,
+        default="weight",
+        choices=["weight", "active_moe"],
+        help=(
+            "Cost model for auto_quantize effective-bits accounting. 'weight' counts all "
+            "quantizable weights equally. 'active_moe' scales routed MoE expert weights by "
+            "--auto_quantize_active_moe_expert_ratio, or infers top_k/num_experts from model config."
+        ),
+    )
+    parser.add_argument(
+        "--auto_quantize_active_moe_expert_ratio",
+        type=float,
+        default=None,
+        help=(
+            "Routed MoE expert active ratio for --auto_quantize_cost_model active_moe. "
+            "For top-k MoE this is top_k / num_experts. If omitted, common model config "
+            "fields such as num_experts_per_tok and num_experts are used when available."
+        ),
+    )
     parser.add_argument(
         "--moe_calib_experts_ratio",
         type=float,
@@ -1434,6 +1464,18 @@ def parse_args() -> argparse.Namespace:
     args = parser.parse_args()
     if args.moe_calib_experts_ratio is not None and not (0.0 < args.moe_calib_experts_ratio <= 1.0):
         parser.error("--moe_calib_experts_ratio must be in the range (0.0, 1.0].")
+    if args.auto_quantize_active_moe_expert_ratio is not None and not (
+        0.0 < args.auto_quantize_active_moe_expert_ratio <= 1.0
+    ):
+        parser.error("--auto_quantize_active_moe_expert_ratio must be in the range (0.0, 1.0].")
+    if (
+        args.auto_quantize_cost_model == "weight"
+        and args.auto_quantize_active_moe_expert_ratio is not None
+    ):
+        parser.error(
+            "--auto_quantize_active_moe_expert_ratio requires "
+            "--auto_quantize_cost_model active_moe."
+        )
 
     if args.specdec_offline_dataset is not None and args.sparsity_fmt != "dense":
         parser.error("--specdec_offline_dataset is only supported with --sparsity_fmt dense (PTQ).")