from __future__ import annotations
import math
from typing import Callable, Iterable, TYPE_CHECKING
if TYPE_CHECKING:
from torch import Tensor
from .base import ModelBase, TextModel, gguf
@ModelBase.register("Jais2ForCausalLM")
# [TAG_HF_EXAMPLE_GATED] inceptionai/Jais-2-8B-Chat is gated
# [TAG_HF_EXAMPLE_MISSING]
class Jais2Model(TextModel):
model_arch = gguf.MODEL_ARCH.JAIS2
def set_gguf_parameters(self):
super().set_gguf_parameters()
hparams = self.hparams
head_dim = hparams.get("head_dim", hparams["hidden_size"] // hparams["num_attention_heads"])
self.gguf_writer.add_rope_dimension_count(head_dim)
@ModelBase.register("JAISLMHeadModel")
@ModelBase.example("inceptionai/jais-family-590m")
class JaisModel(TextModel):
model_arch = gguf.MODEL_ARCH.JAIS
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# SwigLU activation
assert self.hparams["activation_function"] == "swiglu"
# ALiBi position embedding
assert self.hparams["position_embedding_type"] == "alibi"
# Embeddings scale
self.embeddings_scale = 1.0
if 'mup_embeddings_scale' in self.hparams:
self.embeddings_scale = self.hparams['mup_embeddings_scale']
elif 'embeddings_scale' in self.hparams:
self.embeddings_scale = self.hparams['embeddings_scale']
else:
assert False
self.width_scale = 1.0
if 'mup_output_alpha' in self.hparams:
assert 'mup_width_scale' in self.hparams
self.width_scale = self.hparams['mup_output_alpha'] * self.hparams['mup_width_scale']
elif 'width_scale' in self.hparams:
self.width_scale = self.hparams['width_scale']
else:
assert False
self.max_alibi_bias = 8.0
def set_vocab(self):
self._set_vocab_gpt2()
def set_gguf_parameters(self):
self.gguf_writer.add_block_count(self.block_count)
self.gguf_writer.add_context_length(self.hparams["n_positions"])
self.gguf_writer.add_embedding_length(self.hparams["n_embd"])
self.gguf_writer.add_feed_forward_length(self.hparams["n_inner"])
self.gguf_writer.add_head_count(self.hparams["n_head"])
self.gguf_writer.add_layer_norm_eps(self.hparams["layer_norm_epsilon"])
self.gguf_writer.add_file_type(self.ftype)
@classmethod
def filter_tensors(cls, item: tuple[str, Callable[[], Tensor]]) -> tuple[str, Callable[[], Tensor]] | None:
name, gen = item
# we don't need these
if name.endswith((".attn.bias")):
return None
return super().filter_tensors(item)
def modify_tensors(self, data_torch: Tensor, name: str, bid: int | None) -> Iterable[tuple[str, Tensor]]:
if name.endswith(("relative_pe.slopes")):
# Calculate max ALiBi bias (this is the inverse of the ALiBi calculation)
# Some other models has max_alibi_bias spelled out explicitly in the hyperparams,
# but Jais's PyTorch model simply precalculates the slope values and places them
# in relative_pes.slopes
n_head_closest_log2 = 2 ** math.floor(math.log2(self.hparams["n_head"]))
first_val = float(data_torch[0].item())
self.max_alibi_bias = -round(math.log2(first_val) * n_head_closest_log2)
return
if name.endswith((".c_attn.weight", ".c_proj.weight", ".c_fc.weight", ".c_fc2.weight")):
data_torch = data_torch.transpose(1, 0)
new_name = self.map_tensor_name(name)
if new_name == self.format_tensor_name(gguf.MODEL_TENSOR.TOKEN_EMBD):
yield from super().modify_tensors(data_torch * self.embeddings_scale, new_name, bid)
elif new_name == self.format_tensor_name(gguf.MODEL_TENSOR.OUTPUT):
yield from super().modify_tensors(data_torch * self.width_scale, new_name, bid)
else:
yield from super().modify_tensors(data_torch, new_name, bid)
def prepare_tensors(self):
super().prepare_tensors()
self.gguf_writer.add_max_alibi_bias(self.max_alibi_bias)