HiDream-ai-dev / hi_diffusers /models /attention_processor.py
blanchon's picture
first commit
755bbb7
from typing import Optional
import torch
from .attention import HiDreamAttention
try:
from flash_attn_interface import flash_attn_func
USE_FLASH_ATTN3 = True
except:
from flash_attn import flash_attn_func
USE_FLASH_ATTN3 = False
# Copied from https://github.com/black-forest-labs/flux/blob/main/src/flux/math.py
def apply_rope(xq: torch.Tensor, xk: torch.Tensor, freqs_cis: torch.Tensor) -> tuple[torch.Tensor, torch.Tensor]:
xq_ = xq.float().reshape(*xq.shape[:-1], -1, 1, 2)
xk_ = xk.float().reshape(*xk.shape[:-1], -1, 1, 2)
xq_out = freqs_cis[..., 0] * xq_[..., 0] + freqs_cis[..., 1] * xq_[..., 1]
xk_out = freqs_cis[..., 0] * xk_[..., 0] + freqs_cis[..., 1] * xk_[..., 1]
return xq_out.reshape(*xq.shape).type_as(xq), xk_out.reshape(*xk.shape).type_as(xk)
def attention(query: torch.Tensor, key: torch.Tensor, value: torch.Tensor):
if USE_FLASH_ATTN3:
hidden_states = flash_attn_func(query, key, value, causal=False, deterministic=False)[0]
else:
hidden_states = flash_attn_func(query, key, value, dropout_p=0., causal=False)
hidden_states = hidden_states.flatten(-2)
hidden_states = hidden_states.to(query.dtype)
return hidden_states
class HiDreamAttnProcessor_flashattn:
"""Attention processor used typically in processing the SD3-like self-attention projections."""
def __call__(
self,
attn: HiDreamAttention,
image_tokens: torch.FloatTensor,
image_tokens_masks: Optional[torch.FloatTensor] = None,
text_tokens: Optional[torch.FloatTensor] = None,
rope: torch.FloatTensor = None,
*args,
**kwargs,
) -> torch.FloatTensor:
dtype = image_tokens.dtype
batch_size = image_tokens.shape[0]
query_i = attn.q_rms_norm(attn.to_q(image_tokens)).to(dtype=dtype)
key_i = attn.k_rms_norm(attn.to_k(image_tokens)).to(dtype=dtype)
value_i = attn.to_v(image_tokens)
inner_dim = key_i.shape[-1]
head_dim = inner_dim // attn.heads
query_i = query_i.view(batch_size, -1, attn.heads, head_dim)
key_i = key_i.view(batch_size, -1, attn.heads, head_dim)
value_i = value_i.view(batch_size, -1, attn.heads, head_dim)
if image_tokens_masks is not None:
key_i = key_i * image_tokens_masks.view(batch_size, -1, 1, 1)
if not attn.single:
query_t = attn.q_rms_norm_t(attn.to_q_t(text_tokens)).to(dtype=dtype)
key_t = attn.k_rms_norm_t(attn.to_k_t(text_tokens)).to(dtype=dtype)
value_t = attn.to_v_t(text_tokens)
query_t = query_t.view(batch_size, -1, attn.heads, head_dim)
key_t = key_t.view(batch_size, -1, attn.heads, head_dim)
value_t = value_t.view(batch_size, -1, attn.heads, head_dim)
num_image_tokens = query_i.shape[1]
num_text_tokens = query_t.shape[1]
query = torch.cat([query_i, query_t], dim=1)
key = torch.cat([key_i, key_t], dim=1)
value = torch.cat([value_i, value_t], dim=1)
else:
query = query_i
key = key_i
value = value_i
if query.shape[-1] == rope.shape[-3] * 2:
query, key = apply_rope(query, key, rope)
else:
query_1, query_2 = query.chunk(2, dim=-1)
key_1, key_2 = key.chunk(2, dim=-1)
query_1, key_1 = apply_rope(query_1, key_1, rope)
query = torch.cat([query_1, query_2], dim=-1)
key = torch.cat([key_1, key_2], dim=-1)
hidden_states = attention(query, key, value)
if not attn.single:
hidden_states_i, hidden_states_t = torch.split(hidden_states, [num_image_tokens, num_text_tokens], dim=1)
hidden_states_i = attn.to_out(hidden_states_i)
hidden_states_t = attn.to_out_t(hidden_states_t)
return hidden_states_i, hidden_states_t
else:
hidden_states = attn.to_out(hidden_states)
return hidden_states