submission 632161

#!POPCORN leaderboard amd-moe-mxfp4
#!POPCORN gpu MI355X

import os
import torch
from task import input_t, output_t

from aiter import ActivationType, QuantType
from aiter.fused_moe import fused_moe

_PAD_CACHE = {}


def custom_kernel(data: input_t) -> output_t:
    (
        hidden_states,
        gate_up_weight,
        down_weight,
        gate_up_weight_scale,
        down_weight_scale,
        gate_up_weight_shuffled,
        down_weight_shuffled,
        gate_up_weight_scale_shuffled,
        down_weight_scale_shuffled,
        topk_weights,
        topk_ids,
        config,
    ) = data

    M = topk_ids.shape[0]

    # Per-shape kernel backend selection via env vars.
    # get_2stage_cfgs() and get_ksplit() are LRU-cached per shape,
    # so env vars only matter on first (warmup) call.
    if M <= 128:
        # Trigger cktile backend with split_k=2 for decode shapes.
        # BYPASS_TUNE_CONFIG=1 skips CSV kernel selection, forcing
        # the default heuristic path which respects AITER_KSPLIT.
        os.environ["AITER_KSPLIT"] = "2"
        os.environ["AITER_BYPASS_TUNE_CONFIG"] = "1"
    else:
        # Keep CSV-tuned ck2stages for large-M 256-expert shapes,
        # and default ck backend for large-M 32-expert shapes.
        os.environ["AITER_KSPLIT"] = "0"
        os.environ["AITER_BYPASS_TUNE_CONFIG"] = "0"

    cfg_id = id(config)
    cached = _PAD_CACHE.get(cfg_id)
    if cached is not None:
        hidden_pad, intermediate_pad = cached
    else:
        hidden_pad = config["d_hidden_pad"] - config["d_hidden"]
        intermediate_pad = config["d_expert_pad"] - config["d_expert"]
        _PAD_CACHE[cfg_id] = (hidden_pad, intermediate_pad)

    return fused_moe(
        hidden_states, gate_up_weight_shuffled, down_weight_shuffled,
        topk_weights, topk_ids,
        activation=ActivationType.Silu, quant_type=QuantType.per_1x32,
        w1_scale=gate_up_weight_scale_shuffled,
        w2_scale=down_weight_scale_shuffled,
        hidden_pad=hidden_pad, intermediate_pad=intermediate_pad,
    )