File size: 7,975 Bytes
d91766b
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
import os

import torch
import torch.nn as nn
from einops import rearrange

from diffulex.attention import Attention
from diffulex.layer.layernorm import RMSNorm
from diffulex.layer.activation import SiluAndMul
from diffulex.layer.rotary_embedding import get_rope
from diffulex.layer.linear import RowParallelLinear, ColumnParallelLinear
from diffulex.layer.embed_head import VocabParallelEmbedding, ParallelLMHead
from diffulex.model.auto_model import AutoModelForDiffusionLM
from diffulex.model.config.sdar.configuration_sdar import SDARConfig
from diffulex.distributed.parallel_state import fetch_parallel_state


if os.environ.get("TRITON_INTERPRET", None) == "1":
    torch._dynamo.reset()
    torch._dynamo.config.suppress_errors = True
    torch.backends.optimized_mode = False


class SDARAttention(nn.Module):
    """SDAR attention (Diffulex native KV cache path).

    Compatible with Diffulex runner KV cache injection:
    runner sets `self.attn.k_cache` / `self.attn.v_cache` by assigning to modules
    that expose these attributes (see `diffulex/attention/attn_impl.py`).
    """

    def __init__(self, config: SDARConfig) -> None:
        super().__init__()
        parallel_state = fetch_parallel_state()
        tp_size = parallel_state.get_tp_world_size()
        self.total_num_heads = config.num_attention_heads
        assert self.total_num_heads % tp_size == 0
        self.num_heads = self.total_num_heads // tp_size

        self.total_num_kv_heads = config.num_key_value_heads
        assert self.total_num_kv_heads % tp_size == 0
        self.num_kv_heads = self.total_num_kv_heads // tp_size

        head_dim = getattr(config, "head_dim", None)
        self.head_dim = head_dim or (config.hidden_size // self.total_num_heads)
        self.q_size = self.num_heads * self.head_dim
        self.kv_size = self.num_kv_heads * self.head_dim
        self.scaling = self.head_dim**-0.5

        bias = getattr(config, "attention_bias", False)
        self.q_proj = ColumnParallelLinear(
            config.hidden_size,
            self.total_num_heads * self.head_dim,
            bias=bias,
        )
        self.k_proj = ColumnParallelLinear(
            config.hidden_size,
            self.total_num_kv_heads * self.head_dim,
            bias=bias,
        )
        self.v_proj = ColumnParallelLinear(
            config.hidden_size,
            self.total_num_kv_heads * self.head_dim,
            bias=bias,
        )
        self.o_proj = RowParallelLinear(
            self.total_num_heads * self.head_dim,
            config.hidden_size,
            bias=bias,
        )

        # SDAR uses q/k per-head RMSNorm.
        self.q_norm = RMSNorm(self.head_dim, eps=config.rms_norm_eps)
        self.k_norm = RMSNorm(self.head_dim, eps=config.rms_norm_eps)

        self.rotary_emb = get_rope(
            self.head_dim,
            rotary_dim=self.head_dim,
            max_position=config.max_position_embeddings,
            base=getattr(config, "rope_theta", 10000),
            rope_scaling=getattr(config, "rope_scaling", None),
        )

        # Diffulex Attention implements KV cache store/load via injected k_cache/v_cache.
        self.attn = Attention(
            self.num_heads,
            self.head_dim,
            self.scaling,
            self.num_kv_heads,
            attn_impl=getattr(config, "attn_impl", "triton"),
        )

    def forward(
        self,
        positions: torch.Tensor,
        hidden_states: torch.Tensor,
        mask: torch.Tensor | None = None,
    ) -> torch.Tensor:
        q = self.q_proj(hidden_states)
        k = self.k_proj(hidden_states)
        v = self.v_proj(hidden_states)

        q = rearrange(
            self.q_norm(
                rearrange(q, "token (head head_dim) -> token head head_dim", head=self.num_heads)
            ),
            "token head head_dim -> token (head head_dim)",
        )
        k = rearrange(
            self.k_norm(
                rearrange(k, "token (head head_dim) -> token head head_dim", head=self.num_kv_heads)
            ),
            "token head head_dim -> token (head head_dim)",
        )

        q, k = self.rotary_emb(positions, q, k)
        o = self.attn(q, k, v, mask)
        return self.o_proj(o)


class SDARMLP(nn.Module):
    """SDAR MLP: SiLU(gate) * up -> down."""

    def __init__(self, config: SDARConfig) -> None:
        super().__init__()
        self.gate_proj = ColumnParallelLinear(
            config.hidden_size,
            config.intermediate_size,
            bias=False,
        )
        self.up_proj = ColumnParallelLinear(
            config.hidden_size,
            config.intermediate_size,
            bias=False,
        )
        self.down_proj = RowParallelLinear(
            config.intermediate_size,
            config.hidden_size,
            bias=False,
        )
        assert getattr(config, "hidden_act", "silu") == "silu"
        self.act_fn = SiluAndMul()

    def forward(self, x: torch.Tensor) -> torch.Tensor:
        gate = self.gate_proj(x)
        up = self.up_proj(x)
        x = self.act_fn(torch.cat([gate, up], dim=-1))
        return self.down_proj(x)


class SDARDecoderLayer(nn.Module):
    def __init__(self, config: SDARConfig) -> None:
        super().__init__()
        self.self_attn = SDARAttention(config)
        self.mlp = SDARMLP(config)
        self.input_layernorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)
        self.post_attention_layernorm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)

    def forward(
        self,
        positions: torch.Tensor,
        hidden_states: torch.Tensor,
        residual: torch.Tensor | None,
        mask: torch.Tensor | None = None,
    ) -> tuple[torch.Tensor, torch.Tensor]:
        if residual is None:
            residual = hidden_states
            hidden_states = self.input_layernorm(hidden_states)
        else:
            hidden_states, residual = self.input_layernorm(hidden_states, residual)

        hidden_states = self.self_attn(positions, hidden_states, mask)
        hidden_states, residual = self.post_attention_layernorm(hidden_states, residual)
        hidden_states = self.mlp(hidden_states)
        return hidden_states, residual


class SDARModel(nn.Module):
    def __init__(self, config: SDARConfig) -> None:
        super().__init__()
        self.embed_tokens = VocabParallelEmbedding(config.vocab_size, config.hidden_size)
        self.layers = nn.ModuleList([SDARDecoderLayer(config) for _ in range(config.num_hidden_layers)])
        self.norm = RMSNorm(config.hidden_size, eps=config.rms_norm_eps)

    def forward(
        self,
        input_ids: torch.Tensor,
        positions: torch.Tensor,
        mask: torch.Tensor | None = None,
    ) -> torch.Tensor:
        hidden_states = self.embed_tokens(input_ids)
        residual = None
        for layer in self.layers:
            hidden_states, residual = layer(positions, hidden_states, residual, mask)
        hidden_states, _ = self.norm(hidden_states, residual)
        return hidden_states


@AutoModelForDiffusionLM.register("sdar")
class SDARForDiffusionLM(nn.Module):
    packed_modules_mapping = {}

    def __init__(self, config: SDARConfig) -> None:
        super().__init__()
        self.model = SDARModel(config)
        self.lm_head = ParallelLMHead(config.vocab_size, config.hidden_size)
        if getattr(config, "tie_word_embeddings", False):
            self.lm_head.weight.data = self.model.embed_tokens.weight.data

    def forward(
        self,
        input_ids: torch.Tensor,
        positions: torch.Tensor,
        mask: torch.Tensor | None = None,
    ) -> torch.Tensor:
        return self.model(input_ids, positions, mask)

    def compute_logits(self, hidden_states: torch.Tensor) -> torch.Tensor:
        return self.lm_head(hidden_states)


__all__ = [
    "SDARConfig",
    "SDARAttention",
    "SDARMLP",
    "SDARDecoderLayer",
    "SDARModel",
    "SDARForDiffusionLM",
]