GLM-5 · Input features · OpenModelAtlas

78 transformer blocks › 75 MoE blocks › Mixture of experts › Shared expert

Input features

tensorx

The normalized features entering this SwiGLU shared expert.

shape: $x_{\mathrm{ffn}}$ [B batch, T positions, 6144 d]

Sources

Contextual evidence from MoE RMSNorm

RMSNorm owns one gain per feature; it normalizes in float32, casts back to the input precision and multiplies by the gain.

rmsnorm · huggingface/transformers / modeling_glm_moe_dsa.py
Pinned revision 5e4d6304de55 ↗ · lines 48–62

Read code excerpt

class GlmMoeDsaRMSNorm(nn.Module):
    def __init__(self, hidden_size, eps: float = 1e-6) -> None:
        """
        GlmMoeDsaRMSNorm is equivalent to T5LayerNorm
        """
        super().__init__()
        self.weight = nn.Parameter(torch.ones(hidden_size))
        self.variance_epsilon = eps

    def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
        input_dtype = hidden_states.dtype
        hidden_states = hidden_states.to(torch.float32)
        variance = hidden_states.pow(2).mean(-1, keepdim=True)
        hidden_states = hidden_states * torch.rsqrt(variance + self.variance_epsilon)
        return self.weight * hidden_states.to(input_dtype)

Contextual evidence from MoE RMSNorm

A block applies input RMSNorm, attention and a residual addition, then post-attention RMSNorm, the feed-forward network and a second residual addition; the first first_k_dense_replace blocks use the dense MLP, the rest MoE.

block · huggingface/transformers / modeling_glm_moe_dsa.py
Pinned revision 5e4d6304de55 ↗ · lines 586–627

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class GlmMoeDsaDecoderLayer(GradientCheckpointingLayer):
    def __init__(self, config: GlmMoeDsaConfig, layer_idx: int):
        super().__init__()
        self.hidden_size = config.hidden_size
        self.self_attn = GlmMoeDsaAttention(config, layer_idx)

        self.mlp = GlmMoeDsaMoE(config) if config.mlp_layer_types[layer_idx] == "sparse" else GlmMoeDsaMLP(config)

        self.input_layernorm = GlmMoeDsaRMSNorm(config.hidden_size, config.rms_norm_eps)
        self.post_attention_layernorm = GlmMoeDsaRMSNorm(config.hidden_size, config.rms_norm_eps)

    def forward(
        self,
        hidden_states: torch.Tensor,
        attention_mask: torch.Tensor | None = None,
        position_ids: torch.LongTensor | None = None,
        past_key_values: Cache | None = None,
        use_cache: bool | None = False,
        position_embeddings: tuple[torch.Tensor, torch.Tensor] | None = None,
        prev_topk_indices: torch.Tensor | None = None,  # MAIN DIFF with DSV3.2
        **kwargs: Unpack[TransformersKwargs],
    ) -> tuple[torch.Tensor, torch.Tensor | None]:
        residual = hidden_states
        hidden_states = self.input_layernorm(hidden_states)
        # Self Attention
        hidden_states, _, topk_indices = self.self_attn(
            hidden_states=hidden_states,
            attention_mask=attention_mask,
            position_ids=position_ids,
            past_key_values=past_key_values,
            use_cache=use_cache,
            position_embeddings=position_embeddings,
            prev_topk_indices=prev_topk_indices,  # MAIN DIFF with DSV3.2
            **kwargs,
        )
        hidden_states = residual + hidden_states

        residual = hidden_states
        hidden_states = self.post_attention_layernorm(hidden_states)
        hidden_states = self.mlp(hidden_states)
        hidden_states = residual + hidden_states
        return hidden_states, topk_indices

Contextual evidence from Gate projection

The dense feed-forward network is a SwiGLU MLP, down(silu(gate x) ⊙ up x), computed in the input’s precision.

mlp · huggingface/transformers / modeling_glm_moe_dsa.py
Pinned revision 5e4d6304de55 ↗ · lines 465–478

Read code excerpt

class GlmMoeDsaMLP(nn.Module):
    def __init__(self, config, intermediate_size=None):
        super().__init__()
        self.config = config
        self.hidden_size = config.hidden_size
        self.intermediate_size = config.intermediate_size if intermediate_size is None else intermediate_size
        self.gate_proj = nn.Linear(self.hidden_size, self.intermediate_size, bias=False)
        self.up_proj = nn.Linear(self.hidden_size, self.intermediate_size, bias=False)
        self.down_proj = nn.Linear(self.intermediate_size, self.hidden_size, bias=False)
        self.act_fn = ACT2FN[config.hidden_act]

    def forward(self, x):
        down_proj = self.down_proj(self.act_fn(self.gate_proj(x)) * self.up_proj(x))
        return down_proj

Contextual evidence from Gate projection

Attention projections have no bias (attention_bias is false) and the checkpoint stores its weights in bfloat16.

linear · zai-org/GLM-5 / config.json
Pinned revision c183ef8c61fa ↗ · lines 5–7

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  "attention_bias": false,
  "attention_dropout": 0.0,
  "dtype": "bfloat16",