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chore: import upstream snapshot with attribution
2026-07-13 13:23:58 +08:00

489 lines
19 KiB
Python

"""
Implementation for Phi architecture.
"""
import dataclasses
from typing import Any, Dict, Optional, Union # noqa: UP035
from tvm import tirx
from tvm.relax.frontend import nn
from tvm.relax.frontend.nn import Tensor, op
from mlc_llm import op as op_ext
from mlc_llm.model.model_utils import index_last_token
from mlc_llm.nn import PagedKVCache, RopeMode
from mlc_llm.support import logging
from mlc_llm.support import tensor_parallel as tp
from mlc_llm.support.config import ConfigBase
from mlc_llm.support.style import bold
logger = logging.getLogger(__name__)
@dataclasses.dataclass
class Phi1Config(ConfigBase):
"""Configuration of the Phi-1/Phi-1.5 model."""
vocab_size: int = 51200
hidden_size: int = 2048
intermediate_size: int = 8192
num_hidden_layers: int = 24
num_attention_heads: int = 32
layer_norm_eps: float = 1e-5
position_embedding_base: int = 0
partial_rotary_factor: float = 0.5
num_key_value_heads: int = 0
context_window_size: int = 0
prefill_chunk_size: int = 0
head_dim: int = 0
tensor_parallel_shards: int = 1
max_batch_size: int = 1
kwargs: Dict[str, Any] = dataclasses.field(default_factory=dict) # noqa: UP006
def __post_init__(self):
if self.position_embedding_base == 0:
if "rope_theta" in self.kwargs:
self.position_embedding_base = self.kwargs.pop("rope_theta")
else:
self.position_embedding_base = 10000
if self.context_window_size == 0:
for name in ["max_position_embeddings", "max_sequence_length"]:
if name in self.kwargs:
self.context_window_size = self.kwargs.pop(name)
logger.info(
"%s not found in config.json. Falling back to %s (%d)",
bold("context_window_size"),
bold(name),
self.context_window_size,
)
break
else:
raise ValueError(
"Unable to determine the maximum sequence length, because none of "
"`context_window_size`, `max_position_embeddings` or `max_sequence_length` is "
"provided in `config.json`."
)
if self.prefill_chunk_size == 0:
logger.info(
"%s defaults to %d",
bold("prefill_chunk_size"),
min(self.context_window_size, 8192),
)
self.prefill_chunk_size = min(self.context_window_size, 8192)
elif self.prefill_chunk_size > self.context_window_size:
logger.info(
"Overriding %s from %d to %d",
bold("prefill_chunk_size"),
self.prefill_chunk_size,
min(self.context_window_size, 8192),
)
self.prefill_chunk_size = min(self.context_window_size, 8192)
if self.num_key_value_heads == 0 or self.num_key_value_heads is None:
self.num_key_value_heads = self.num_attention_heads
if self.intermediate_size == 0 or self.intermediate_size is None:
self.intermediate_size = 4 * self.hidden_size
if self.head_dim == 0:
self.head_dim = self.hidden_size // self.num_attention_heads
assert self.head_dim * self.num_attention_heads == self.hidden_size
assert self.num_attention_heads % self.num_key_value_heads == 0
@dataclasses.dataclass
class PhiConfig(ConfigBase):
"""Configuration of the Phi-2 model."""
model_type: str # "phi", "phi-msft", "mixformer-sequential"
vocab_size: int = 51200
n_positions: int = 2048
n_embd: int = 2560
n_layer: int = 32
n_inner: int = 0
n_head: int = 32
rotary_dim: int = 32
position_embedding_base: int = 0
layer_norm_epsilon: float = 1e-5
context_window_size: int = 0
prefill_chunk_size: int = 0
n_head_kv: int = 0
head_dim: int = 0
tensor_parallel_shards: int = 1
kwargs: Dict[str, Any] = dataclasses.field(default_factory=dict) # noqa: UP006
def __post_init__(self):
if self.position_embedding_base == 0:
if "rope_theta" in self.kwargs:
self.position_embedding_base = self.kwargs.pop("rope_theta")
else:
self.position_embedding_base = 10000
if self.context_window_size == 0:
for name in ["max_position_embeddings", "max_sequence_length"]:
if name in self.kwargs:
self.context_window_size = self.kwargs.pop(name)
logger.info(
"%s not found in config.json. Falling back to %s (%d)",
bold("context_window_size"),
bold(name),
self.context_window_size,
)
break
else:
self.context_window_size = self.n_positions
logger.info(
"%s not found in config.json. Falling back to %s (%d)",
bold("context_window_size"),
"n_positions",
self.context_window_size,
)
if self.prefill_chunk_size == 0:
self.prefill_chunk_size = self.context_window_size
self.prefill_chunk_size = min(self.prefill_chunk_size, self.context_window_size)
if self.n_head_kv == 0 or self.n_head_kv is None:
self.n_head_kv = self.n_head
if self.n_inner == 0 or self.n_inner is None:
self.n_inner = 4 * self.n_embd
if self.head_dim == 0:
self.head_dim = self.n_embd // self.n_head
assert self.head_dim * self.n_head == self.n_embd
assert self.n_head % self.n_head_kv == 0
@staticmethod
def from_phi1(config: Phi1Config) -> "PhiConfig":
"Build PhiConig from a Phi1Config."
return PhiConfig(
model_type="phi",
vocab_size=config.vocab_size,
n_positions=config.context_window_size,
n_embd=config.hidden_size,
n_layer=config.num_hidden_layers,
n_inner=config.intermediate_size,
n_head=config.num_attention_heads,
rotary_dim=int(config.partial_rotary_factor * config.head_dim),
position_embedding_base=config.position_embedding_base,
layer_norm_epsilon=config.layer_norm_eps,
context_window_size=config.context_window_size,
prefill_chunk_size=config.prefill_chunk_size,
n_head_kv=config.num_key_value_heads,
head_dim=config.head_dim,
tensor_parallel_shards=config.tensor_parallel_shards,
kwargs=config.kwargs,
)
class PhiMLP(nn.Module):
def __init__(self, config: PhiConfig):
super().__init__()
if config.n_inner % config.tensor_parallel_shards != 0:
raise ValueError(
f"Cannot split MLP intermediate size {config.n_inner} "
f"evenly to {config.tensor_parallel_shards} GPUs."
)
self.intermediate_size = config.n_inner // config.tensor_parallel_shards
self.fc1 = nn.Linear(config.n_embd, self.intermediate_size)
self.fc2 = nn.Linear(self.intermediate_size, config.n_embd)
def forward(self, hidden_states: Tensor):
hidden_states = self.fc1(hidden_states)
hidden_states = op.gelu(hidden_states, approximate="tanh")
hidden_states = self.fc2(hidden_states)
return hidden_states
class PhiMHA(nn.Module):
def __init__(self, config: PhiConfig):
self.num_q_heads = config.n_head // config.tensor_parallel_shards
assert config.n_head % config.tensor_parallel_shards == 0, (
f"n_head({config.n_head}) must be divisible by tensor_parallel_shards"
)
self.n_head_kv = config.n_head_kv // config.tensor_parallel_shards
assert config.n_head_kv % config.tensor_parallel_shards == 0, (
f"n_head({config.n_head_kv}) must be divisible by tensor_parallel_shards"
)
self.head_dim = config.head_dim
op_size = self.head_dim * (self.num_q_heads + 2 * self.n_head_kv)
hidden_size = config.n_embd
self.Wqkv = nn.Linear(hidden_size, op_size, bias=True)
self.out_proj = nn.Linear(self.num_q_heads * self.head_dim, hidden_size, bias=True)
def forward(self, hidden_states: Tensor, paged_kv_cache: PagedKVCache, layer_id: int):
d, h_q, h_kv = self.head_dim, self.num_q_heads, self.n_head_kv
b, s, _ = hidden_states.shape
# QKV Projection
qkv = self.Wqkv(hidden_states)
qkv = op.reshape(qkv, (b, s, h_q + h_kv + h_kv, d))
# Attention
output = op.reshape(
paged_kv_cache.attention_with_fused_qkv(
layer_id, qkv, self.num_q_heads, sm_scale=self.head_dim**-0.5
),
(b, s, h_q * d),
)
return self.out_proj(output)
class PhiParallelBlock(nn.Module):
def __init__(self, config: PhiConfig):
super().__init__()
self.ln = nn.LayerNorm(config.n_embd, eps=config.layer_norm_epsilon)
self.mixer = PhiMHA(config)
self.mlp = PhiMLP(config)
def _set_tp():
def _set(param, hint):
param.attrs["shard_strategy"] = hint
hd = config.head_dim
q = self.mixer.num_q_heads * hd
k = self.mixer.n_head_kv * hd
v = self.mixer.n_head_kv * hd
_set(
self.mixer.Wqkv.weight,
tp.ShardSingleDim("_shard_qkv_weight", segs=[q, k, v], dim=0),
)
_set(
self.mixer.Wqkv.bias,
tp.ShardSingleDim("_shard_qkv_bias", segs=[q, k, v], dim=0),
)
_set(self.mixer.out_proj.weight, tp.ShardSingleDim("_shard_o_weight", dim=1))
_set(self.mlp.fc1.weight, tp.ShardSingleDim("_shard_mlp_fc1_weight", dim=0))
_set(self.mlp.fc1.bias, tp.ShardSingleDim("_shard_mlp_fc1_bias", dim=0))
_set(self.mlp.fc2.weight, tp.ShardSingleDim("_shard_mlp_fc2_weight", dim=1))
self.tensor_parallel_shards = config.tensor_parallel_shards
_set_tp()
def forward(self, hidden_states: Tensor, paged_kv_cache: PagedKVCache, layer_id: int):
residual = hidden_states
hidden_states = self.ln(hidden_states)
with (
tp.shard_bias(self.mixer.out_proj, self.tensor_parallel_shards),
tp.shard_bias(self.mlp.fc2, self.tensor_parallel_shards),
):
attn_outputs = self.mixer(hidden_states, paged_kv_cache, layer_id)
feed_forward_hidden_states = self.mlp(hidden_states)
hidden_states = self._apply_parallel_residual(
attn_outputs, feed_forward_hidden_states, residual
)
return hidden_states
def _apply_parallel_residual(self, attn_out, mlp_out, residual):
if self.tensor_parallel_shards > 1:
return op.ccl_allreduce(
attn_out + mlp_out + residual / self.tensor_parallel_shards, "sum"
)
return attn_out + mlp_out + residual
class PhiCausalLMHead(nn.Module):
def __init__(self, config: PhiConfig) -> None:
super().__init__()
self.ln = nn.LayerNorm(config.n_embd, eps=config.layer_norm_epsilon)
self.linear = nn.Linear(config.n_embd, "vocab_size")
def forward(self, hidden_states: Tensor):
hidden_states = self.ln(hidden_states)
logits = self.linear(hidden_states)
if logits.dtype != "float32":
logits = logits.astype("float32")
return logits
class PhiModel(nn.Module):
def __init__(self, config: PhiConfig) -> None:
super().__init__()
self.embd = nn.Embedding(config.vocab_size, config.n_embd)
self.h = nn.ModuleList([PhiParallelBlock(config) for _ in range(config.n_layer)])
def forward(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
hidden_states = input_embed
for layer_id, layer in enumerate(self.h):
hidden_states = layer(hidden_states, paged_kv_cache, layer_id)
return hidden_states
class PhiForCausalLM(nn.Module):
def __init__(self, config: Union[PhiConfig, Phi1Config]) -> None:
super().__init__()
if isinstance(config, Phi1Config):
config = PhiConfig.from_phi1(config)
self.transformer = PhiModel(config)
self.lm_head = PhiCausalLMHead(config)
self.num_hidden_layers = config.n_layer
self.num_attention_heads = config.n_head
self.num_key_value_heads = config.n_head_kv
self.head_dim = config.head_dim
self.hidden_size = config.n_embd
self.vocab_size = config.vocab_size
self.rope_theta = config.position_embedding_base
self.tensor_parallel_shards = config.tensor_parallel_shards
self.rotary_dim = config.rotary_dim
self.dtype = "float32"
def to(self, dtype: Optional[str] = None):
super().to(dtype=dtype)
if dtype is not None:
self.dtype = dtype
def batch_forward(
self,
input_embeds: Tensor,
paged_kv_cache: PagedKVCache,
logit_positions: Optional[Tensor] = None,
):
op_ext.configure()
hidden_states = self.transformer(input_embeds, paged_kv_cache)
if logit_positions is not None:
hidden_states = op.take(hidden_states, logit_positions, axis=1)
lm_logits = self.lm_head(hidden_states)
if lm_logits.dtype != "float32":
lm_logits = lm_logits.astype("float32")
return lm_logits
def prefill(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
op_ext.configure()
hidden_states = self.transformer(input_embed, paged_kv_cache)
hidden_states = index_last_token(hidden_states)
logits = self.lm_head(hidden_states)
if logits.dtype != "float32":
logits = logits.astype("float32")
return logits, paged_kv_cache
def decode(self, input_embed: Tensor, paged_kv_cache: PagedKVCache):
op_ext.configure()
hidden_states = self.transformer(input_embed, paged_kv_cache)
logits = self.lm_head(hidden_states)
if logits.dtype != "float32":
logits = logits.astype("float32")
return logits, paged_kv_cache
def batch_prefill(
self,
input_embeds: Tensor,
logit_positions: Tensor,
paged_kv_cache: PagedKVCache,
):
if self.tensor_parallel_shards > 1:
logit_positions = op.ccl_broadcast_from_worker0(logit_positions)
logits = self.batch_forward(input_embeds, paged_kv_cache, logit_positions)
return logits, paged_kv_cache
def batch_decode(self, input_embeds: Tensor, paged_kv_cache: PagedKVCache):
logits = self.batch_forward(input_embeds, paged_kv_cache)
return logits, paged_kv_cache
def batch_verify(self, input_embeds: Tensor, paged_kv_cache: PagedKVCache):
logits = self.batch_forward(input_embeds, paged_kv_cache)
return logits, paged_kv_cache
def embed(self, input_ids: Tensor):
if self.tensor_parallel_shards > 1:
input_ids = op.ccl_broadcast_from_worker0(input_ids)
embeds = self.transformer.embd(input_ids)
return embeds
def create_paged_kv_cache(
self,
max_batch_size: tirx.Var,
max_total_seq_len: tirx.Var,
prefill_chunk_size: tirx.Var,
page_size: tirx.Var,
support_sliding_window: tirx.Var,
) -> PagedKVCache:
return PagedKVCache.create_generic(
attn_kind="mha",
max_batch_size=max_batch_size,
max_total_seq_len=max_total_seq_len,
prefill_chunk_size=prefill_chunk_size,
page_size=page_size,
support_sliding_window=support_sliding_window,
num_hidden_layers=self.num_hidden_layers,
num_attention_heads=self.num_attention_heads // self.tensor_parallel_shards,
num_key_value_heads=self.num_key_value_heads // self.tensor_parallel_shards,
qk_head_dim=self.head_dim,
v_head_dim=self.head_dim,
rope_mode=RopeMode.NORMAL,
rope_scale=1,
rope_theta=self.rope_theta,
rotary_dim=self.rotary_dim,
dtype=self.dtype,
)
def get_default_spec(self):
mod_spec = {
"embed": {
"input_ids": nn.spec.Tensor(["seq_len"], "int32"),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"prefill": {
"input_embed": nn.spec.Tensor([1, "seq_len", self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"decode": {
"input_embed": nn.spec.Tensor([1, 1, self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_prefill": {
"input_embeds": nn.spec.Tensor([1, "seq_len", self.hidden_size], self.dtype),
"logit_positions": nn.spec.Tensor(["batch_size"], "int32"),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_decode": {
"input_embeds": nn.spec.Tensor(["batch_size", 1, self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"batch_verify": {
"input_embeds": nn.spec.Tensor([1, "seq_len", self.hidden_size], self.dtype),
"paged_kv_cache": nn.spec.Object(object_type=PagedKVCache),
"$": {
"param_mode": "packed",
"effect_mode": "none",
},
},
"create_paged_kv_cache": {
"max_batch_size": int,
"max_total_seq_len": int,
"prefill_chunk_size": int,
"page_size": int,
"support_sliding_window": int,
"$": {
"param_mode": "none",
"effect_mode": "none",
},
},
}
return nn.spec.ModuleSpec.from_raw(mod_spec, self)