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Fix Gemma

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This commit is contained in:
Daniel Han 2024-07-19 09:27:18 -07:00
commit 565a5a3894
1 changed files with 15 additions and 6 deletions
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21
unsloth/models/gemma.py
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@ -210,22 +210,24 @@ class GemmaFixedRotaryEmbedding(torch.nn.Module):
self.dim = dim
self.max_position_embeddings = max_position_embeddings
self.base = base
# Dynamic RoPE we first set it to a max of 4 * 8192 tokens then we iteratively grow this
self.current_rope_size = min(4 * 8192, self.max_position_embeddings)
# Build here to make `torch.jit.trace` work.
self._set_cos_sin_cache(seq_len=max_position_embeddings, device=device, dtype=torch.get_default_dtype())
self._set_cos_sin_cache(seq_len=self.current_rope_size, device=device, dtype=torch.get_default_dtype())
pass
def _set_cos_sin_cache(self, seq_len, device, dtype):
# Note: on the original Llama codebase, these tensors are created on the target device (and not on CPU) and
# in FP32. They are applied (multiplied) in FP32 as well.
self.max_seq_len_cached = seq_len
self.current_rope_size = seq_len
# The difference is we do division explicity instead of t * (1/x) ie we do t/x.
freq_exponents = (2.0 / self.dim) * (
torch.arange(self.dim // 2, dtype = torch.int64, device = "cpu").float()
)
timescale = self.base**freq_exponents
positions = torch.arange(self.max_seq_len_cached, device = "cpu", dtype = torch.int64).float()
positions = torch.arange(self.current_rope_size, device = "cpu", dtype = torch.int64).float()
radians_new = positions[..., None] / timescale[None, None, :]
radians_new = radians_new.squeeze(0)
@ -239,7 +241,7 @@ class GemmaFixedRotaryEmbedding(torch.nn.Module):
def forward(self, x, position_ids=None, seq_len=None):
# x: [bs, num_attention_heads, seq_len, head_size]
if seq_len > self.max_seq_len_cached:
if seq_len > self.current_rope_size:
self._set_cos_sin_cache(seq_len=seq_len, device=x.device, dtype=x.dtype)
return (
@ -247,6 +249,13 @@ class GemmaFixedRotaryEmbedding(torch.nn.Module):
self.sin_cached[:seq_len].to(dtype=x.dtype),
)
pass
def extend_rope_embedding(self, x, seq_len):
if seq_len <= self.current_rope_size: return
# Iteratively grow by increments of 8192
self.current_rope_size = int(round(seq_len / 8192)) * 8192
self._set_cos_sin_cache(self.current_rope_size, device = "cuda:0", dtype = x.dtype)
pass
pass
@ -263,14 +272,14 @@ class GemmaFixedLinearScalingRotaryEmbedding(GemmaFixedRotaryEmbedding):
def _set_cos_sin_cache(self, seq_len, device, dtype):
# Note: on the original Llama codebase, these tensors are created on the target device (and not on CPU) and
# in FP32. They are applied (multiplied) in FP32 as well.
self.max_seq_len_cached = seq_len
self.current_rope_size = seq_len
# The difference is we do division explicity instead of t * (1/x) ie we do t/x.
freq_exponents = (2.0 / self.dim) * (
torch.arange(self.dim // 2, dtype = torch.int64, device = "cpu").float()
)
timescale = self.base**freq_exponents
positions = torch.arange(self.max_seq_len_cached, device = "cpu", dtype = torch.int64).float()
positions = torch.arange(self.current_rope_size, device = "cpu", dtype = torch.int64).float()
positions = positions / self.scaling_factor
radians_new = positions[..., None] / timescale[None, None, :]
radians_new = radians_new.squeeze(0)