zaydzuhri's picture
Add files using upload-large-folder tool
f72219a verified
raw
history blame
56.3 kB
# -*- coding: utf-8 -*-
# Copyright (c) 2023-2025, Songlin Yang, Yu Zhang, Yuqi Pan
from typing import Optional, Tuple
import torch
import torch.nn.functional as F
import triton
import triton.language as tl
from fla.modules.layernorm import group_norm
from fla.ops.common.utils import prepare_chunk_indices, prepare_chunk_offsets
from fla.utils import autocast_custom_bwd, autocast_custom_fwd, input_guard
@triton.heuristics({
'USE_INITIAL_STATE': lambda args: args['h0'] is not None,
'USE_INITIAL_STATE_B': lambda args: args['hb0'] is not None,
'STORE_FINAL_STATE': lambda args: args['ht'] is not None,
'USE_OFFSETS': lambda args: args['offsets'] is not None,
})
@triton.autotune(
configs=[
triton.Config({}, num_warps=num_warps)
for num_warps in [1, 2, 4, 8]
],
key=['BT', 'BK', 'BV']
)
@triton.jit(do_not_specialize=['T'])
def chunk_ttt_linear_fwd_kernel_h(
k,
v,
v_new,
eta,
w,
b,
eps,
h,
hb,
h0,
hb0,
ht,
hbt,
offsets,
chunk_offsets,
T,
H: tl.constexpr,
K: tl.constexpr,
V: tl.constexpr,
BT: tl.constexpr,
BK: tl.constexpr,
BV: tl.constexpr,
NT: tl.constexpr,
USE_INITIAL_STATE: tl.constexpr,
USE_INITIAL_STATE_B: tl.constexpr,
STORE_FINAL_STATE: tl.constexpr,
USE_OFFSETS: tl.constexpr,
HEAD_FIRST: tl.constexpr,
):
i_k, i_v, i_nh = tl.program_id(0), tl.program_id(1), tl.program_id(2)
i_n, i_h = i_nh // H, i_nh % H
if USE_OFFSETS:
bos, eos = tl.load(offsets + i_n).to(tl.int32), tl.load(offsets + i_n + 1).to(tl.int32)
T = eos - bos
NT = tl.cdiv(T, BT)
boh = tl.load(chunk_offsets + i_n).to(tl.int32)
else:
bos, eos = i_n * T, i_n * T + T
NT = tl.cdiv(T, BT)
boh = i_n * NT
# [BK, BV]
b_h = tl.zeros([BK, BV], dtype=tl.float32)
# [BV]
b_hb = tl.zeros([BV], dtype=tl.float32)
if USE_INITIAL_STATE:
p_h0 = tl.make_block_ptr(h0 + i_nh * K * V, (K, V), (V, 1), (i_k * BK, i_v * BV), (BK, BV), (1, 0))
b_h = tl.load(p_h0, boundary_check=(0, 1), padding_option="zero").to(tl.float32)
if USE_INITIAL_STATE_B:
p_hb0 = tl.make_block_ptr(hb0 + i_nh * V, (V,), (1,), (i_v * BV,), (BV,), (0,))
b_hb = tl.load(p_hb0, boundary_check=(0,), padding_option="zero").to(tl.float32)
offs = tl.arange(0, BV)
b_w = tl.load(w + i_h * V + offs, mask=offs < V, other=0.)
b_b = tl.load(b + i_h * V + offs, mask=offs < V, other=0.)
for i_t in range(NT):
if HEAD_FIRST:
p_h = tl.make_block_ptr(h + (i_nh * NT + i_t) * K*V, (K, V), (V, 1), (i_k * BK, i_v * BV), (BK, BV), (1, 0))
p_hb = tl.make_block_ptr(hb + (i_nh * NT + i_t) * V, (V,), (1,), (i_v * BV,), (BV,), (0,))
else:
p_h = tl.make_block_ptr(h + ((boh + i_t) * H + i_h) * K*V, (K, V), (V, 1), (i_k * BK, i_v * BV), (BK, BV), (1, 0))
p_hb = tl.make_block_ptr(hb + ((boh + i_t) * H + i_h) * V, (V,), (1,), (i_v * BV,), (BV,), (0,))
tl.store(p_h, b_h.to(p_h.dtype.element_ty), boundary_check=(0, 1))
tl.store(p_hb, b_hb.to(p_hb.dtype.element_ty), boundary_check=(0,))
if HEAD_FIRST:
p_k = tl.make_block_ptr(k+i_nh*T*K, (K, T), (1, K), (i_k * BK, i_t * BT), (BK, BT), (0, 1))
p_v = tl.make_block_ptr(v+i_nh*T*V, (T, V), (V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_v_new = tl.make_block_ptr(v_new+i_nh*T*V, (T, V), (V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_eta_last = eta+i_nh*T+T-1 if i_t == NT-1 else eta+i_nh*T+i_t*BT+BT-1
else:
p_k = tl.make_block_ptr(k+(bos*H+i_h)*K, (K, T), (1, H*K), (i_k * BK, i_t * BT), (BK, BT), (0, 1))
p_v = tl.make_block_ptr(v+(bos*H+i_h)*V, (T, V), (H*V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_v_new = tl.make_block_ptr(v_new+(bos*H+i_h)*V, (T, V), (H*V, 1), (i_t*BT, i_v * BV), (BT, BV), (1, 0))
p_eta_last = eta+bos*H+i_h + (T-1)*H if i_t == NT-1 else eta+bos*H+i_h + (i_t*BT+BT-1)*H
b_k = tl.load(p_k, boundary_check=(0, 1), padding_option="zero")
b_v = tl.load(p_v, boundary_check=(0, 1), padding_option="zero")
b_kh = tl.dot(tl.trans(b_k), b_h.to(b_k.dtype), allow_tf32=False).to(tl.float32) + b_hb[None, :]
b_kh = tl.where((offs < V)[None, :], b_kh, 0.)
mean = tl.sum(b_kh, axis=1, keep_dims=True) / V
xbar = tl.where((offs < V)[None, :], b_kh - mean, 0.)
var = tl.sum(xbar * xbar, axis=1, keep_dims=True) / V
rstd = 1 / tl.sqrt(var.to(tl.float32) + eps)
b_kh_hat = (b_kh - mean) * rstd
b_v = b_kh_hat.to(b_k.dtype) * b_w[None, :].to(b_k.dtype) + \
b_b[None, :].to(b_k.dtype) - b_v.to(b_k.dtype) + tl.trans(b_k)
b_v = tl.where((offs < V)[None, :], b_v * b_w[None, :].to(b_k.dtype), 0.)
b_v2 = rstd * (V * b_v - tl.sum(b_v, axis=1, keep_dims=True) - b_kh_hat.to(b_k.dtype)
* tl.sum(b_v * b_kh_hat.to(b_k.dtype), axis=1, keep_dims=True)) / V
tl.store(p_v_new, b_v2.to(p_v_new.dtype.element_ty), boundary_check=(0, 1))
b_eta_last = tl.load(p_eta_last)
b_h = b_h - tl.dot(b_eta_last * b_k, b_v2.to(b_k.dtype), allow_tf32=False)
b_hb = b_hb - tl.sum(b_eta_last * b_v2.to(b_k.dtype), axis=0)
if STORE_FINAL_STATE:
p_ht = tl.make_block_ptr(ht + i_nh * K*V, (K, V), (V, 1), (i_k * BK, i_v * BV), (BK, BV), (1, 0))
p_hbt = tl.make_block_ptr(hbt + i_nh * V, (V,), (1,), (i_v * BV,), (BV,), (0,))
tl.store(p_ht, b_h.to(p_ht.dtype.element_ty), boundary_check=(0, 1))
tl.store(p_hbt, b_hb.to(p_hbt.dtype.element_ty), boundary_check=(0,))
@triton.heuristics({
'USE_OFFSETS': lambda args: args['offsets'] is not None,
})
@triton.autotune(
configs=[
triton.Config({}, num_warps=num_warps, num_stages=num_stages)
for num_warps in [2, 4, 8]
for num_stages in [2, 3]
],
key=['BT'],
)
@triton.jit(do_not_specialize=['T'])
def chunk_ttt_linear_fwd_kernel_o(
q,
k,
v,
eta,
h,
hb,
o,
offsets,
indices,
scale,
T,
H: tl.constexpr,
K: tl.constexpr,
V: tl.constexpr,
BT: tl.constexpr,
BK: tl.constexpr,
BV: tl.constexpr,
USE_OFFSETS: tl.constexpr,
HEAD_FIRST: tl.constexpr,
):
i_v, i_t, i_bh = tl.program_id(0), tl.program_id(1), tl.program_id(2)
i_b, i_h = i_bh // H, i_bh % H
if USE_OFFSETS:
i_tg = i_t
i_n, i_t = tl.load(indices + i_t * 2).to(tl.int32), tl.load(indices + i_t * 2 + 1).to(tl.int32)
bos, eos = tl.load(offsets + i_n).to(tl.int32), tl.load(offsets + i_n + 1).to(tl.int32)
T = eos - bos
NT = tl.cdiv(T, BT)
else:
NT = tl.cdiv(T, BT)
i_tg = i_b * NT + i_t
bos, eos = i_b * T, i_b * T + T
# offset calculation
q += (i_bh * T * K) if HEAD_FIRST else ((bos * H + i_h) * K)
k += (i_bh * T * K) if HEAD_FIRST else ((bos * H + i_h) * K)
v += (i_bh * T * V) if HEAD_FIRST else ((bos * H + i_h) * V)
eta += (i_bh * T) if HEAD_FIRST else (bos * H + i_h)
o += (i_bh * T * V) if HEAD_FIRST else ((bos * H + i_h) * V)
h += ((i_bh * NT + i_t) * K * V) if HEAD_FIRST else ((i_tg * H + i_h) * K * V)
hb += ((i_bh * NT + i_t) * V) if HEAD_FIRST else ((i_tg * H + i_h) * V)
stride_qk = K if HEAD_FIRST else H*K
stride_vo = V if HEAD_FIRST else H*V
stride_eta = 1 if HEAD_FIRST else H
p_q = tl.make_block_ptr(q, (T, K), (stride_qk, 1), (i_t * BT, 0), (BT, BK), (1, 0))
p_k = tl.make_block_ptr(k, (K, T), (1, stride_qk), (0, i_t * BT), (BK, BT), (0, 1))
p_eta = tl.make_block_ptr(eta, (T,), (stride_eta,), (i_t * BT,), (BT,), (0,))
p_h = tl.make_block_ptr(h, (K, V), (V, 1), (0, i_v * BV), (BK, BV), (1, 0))
p_hb = tl.make_block_ptr(hb, (V,), (1,), (i_v * BV,), (BV,), (0,))
# [BT, BK]
b_q = tl.load(p_q, boundary_check=(0, 1), padding_option="zero")
# [BK, BT]
b_k = tl.load(p_k, boundary_check=(0, 1), padding_option="zero")
# [BT, 1]
b_eta = tl.load(p_eta, boundary_check=(0,), padding_option="zero")
# [BK, BV]
b_h = tl.load(p_h, boundary_check=(0, 1), padding_option="zero")
# [BV]
b_hb = tl.load(p_hb, boundary_check=(0,), padding_option="zero")
# [BT, BK] @ [BK, BV] -> [BT, BV]
b_o = tl.dot(b_q, b_h, allow_tf32=False)
# [BT, BK] @ [BK, BT] -> [BT, BT]
b_A = tl.dot(b_q, b_k, allow_tf32=False)
o_i = tl.arange(0, BT)
m_A = o_i[:, None] >= o_i[None, :]
b_A = tl.where(m_A, b_A, 0)
b_Ae = tl.where(m_A, b_eta[:, None], 0.0)
p_v = tl.make_block_ptr(v, (T, V), (stride_vo, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_o = tl.make_block_ptr(o, (T, V), (stride_vo, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
b_v = tl.load(p_v, boundary_check=(0, 1), padding_option="zero")
b_o = (b_o - tl.dot(b_eta[:, None] * b_A.to(b_v.dtype), b_v, allow_tf32=False)) * scale
b_o += b_hb[None, :] - tl.dot(b_Ae.to(b_v.dtype), b_v, allow_tf32=False)
tl.store(p_o, b_o.to(p_o.dtype.element_ty), boundary_check=(0, 1))
@triton.heuristics({
'USE_INITIAL_STATE': lambda args: args['h0'] is not None,
'USE_INITIAL_STATE_B': lambda args: args['hb0'] is not None,
'USE_OFFSETS': lambda args: args['offsets'] is not None,
})
@triton.autotune(
configs=[
triton.Config({}, num_warps=num_warps)
for num_warps in [1, 2, 4, 8]
],
key=['BT', 'BK', 'BV'],
)
@triton.jit(do_not_specialize=['T'])
def chunk_ttt_linear_bwd_kernel_h(
k,
v,
v_new,
eta,
w,
b,
eps,
h,
h0,
hb0,
x,
y,
r,
offsets,
chunk_offsets,
T,
H: tl.constexpr,
K: tl.constexpr,
V: tl.constexpr,
BT: tl.constexpr,
BK: tl.constexpr,
BV: tl.constexpr,
NT: tl.constexpr,
USE_INITIAL_STATE: tl.constexpr,
USE_INITIAL_STATE_B: tl.constexpr,
USE_OFFSETS: tl.constexpr,
HEAD_FIRST: tl.constexpr,
):
i_k, i_v, i_nh = tl.program_id(0), tl.program_id(1), tl.program_id(2)
i_n, i_h = i_nh // H, i_nh % H
if USE_OFFSETS:
bos, eos = tl.load(offsets + i_n).to(tl.int32), tl.load(offsets + i_n + 1).to(tl.int32)
T = eos - bos
NT = tl.cdiv(T, BT)
boh = tl.load(chunk_offsets + i_n).to(tl.int32)
else:
bos, eos = i_n * T, i_n * T + T
NT = tl.cdiv(T, BT)
boh = i_n * NT
# [BK, BV]
b_h = tl.zeros([BK, BV], dtype=tl.float32)
# [BV]
b_hb = tl.zeros([BV], dtype=tl.float32)
if USE_INITIAL_STATE:
p_h0 = tl.make_block_ptr(h0 + i_nh * K * V, (K, V), (V, 1), (i_k * BK, i_v * BV), (BK, BV), (1, 0))
b_h = tl.load(p_h0, boundary_check=(0, 1), padding_option="zero").to(tl.float32)
if USE_INITIAL_STATE_B:
p_hb0 = tl.make_block_ptr(hb0 + i_nh * V, (V,), (1,), (i_v * BV,), (BV,), (0,))
b_hb = tl.load(p_hb0, boundary_check=(0,), padding_option="zero").to(tl.float32)
offs = tl.arange(0, BV)
b_w = tl.load(w + i_h * V + offs, mask=offs < V, other=0.)
b_b = tl.load(b + i_h * V + offs, mask=offs < V, other=0.)
for i_t in range(NT):
if HEAD_FIRST:
p_h = tl.make_block_ptr(h + (i_nh * NT + i_t) * K*V, (K, V), (V, 1), (i_k * BK, i_v * BV), (BK, BV), (1, 0))
else:
p_h = tl.make_block_ptr(h + ((boh + i_t) * H + i_h) * K*V, (K, V), (V, 1), (i_k * BK, i_v * BV), (BK, BV), (1, 0))
tl.store(p_h, b_h.to(p_h.dtype.element_ty), boundary_check=(0, 1))
if HEAD_FIRST:
p_k = tl.make_block_ptr(k+i_nh*T*K, (K, T), (1, K), (i_k * BK, i_t * BT), (BK, BT), (0, 1))
p_v = tl.make_block_ptr(v+i_nh*T*V, (T, V), (V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_v_new = tl.make_block_ptr(v_new+i_nh*T*V, (T, V), (V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_x = tl.make_block_ptr(x+i_nh*T*V, (T, V), (V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_y = tl.make_block_ptr(y+i_nh*T*V, (T, V), (V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_r = tl.make_block_ptr(r+i_nh*T, (T, 1), (1, 1), (i_t * BT, 0), (BT, 1), (1, 0))
p_eta_last = eta+i_nh*T+T-1 if i_t == NT-1 else eta+i_nh*T+i_t*BT+BT-1
else:
p_k = tl.make_block_ptr(k+(bos*H+i_h)*K, (K, T), (1, H*K), (i_k * BK, i_t * BT), (BK, BT), (0, 1))
p_v = tl.make_block_ptr(v+(bos*H+i_h)*V, (T, V), (H*V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_v_new = tl.make_block_ptr(v_new+(bos*H+i_h)*V, (T, V), (H*V, 1), (i_t*BT, i_v * BV), (BT, BV), (1, 0))
p_x = tl.make_block_ptr(x+(bos*H+i_h)*V, (T, V), (H*V, 1), (i_t*BT, i_v * BV), (BT, BV), (1, 0))
p_y = tl.make_block_ptr(y+(bos*H+i_h)*V, (T, V), (H*V, 1), (i_t*BT, i_v * BV), (BT, BV), (1, 0))
p_r = tl.make_block_ptr(r+bos*H+i_h, (T, 1), (H, 1), (i_t*BT, 0), (BT, 1), (1, 0))
p_eta_last = eta+bos*H+i_h + (T-1)*H if i_t == NT-1 else eta+bos*H+i_h + (i_t*BT+BT-1)*H
b_k = tl.load(p_k, boundary_check=(0, 1), padding_option="zero")
b_v = tl.load(p_v, boundary_check=(0, 1), padding_option="zero")
b_kh = tl.dot(tl.trans(b_k), b_h.to(b_k.dtype), allow_tf32=False).to(tl.float32) + b_hb[None, :]
b_kh = tl.where((offs < V)[None, :], b_kh, 0.)
mean = tl.sum(b_kh, axis=1, keep_dims=True) / V
xbar = tl.where((offs < V)[None, :], b_kh - mean, 0.)
var = tl.sum(xbar * xbar, axis=1, keep_dims=True) / V
rstd = 1 / tl.sqrt(var.to(tl.float32) + eps)
b_kh_hat = (b_kh - mean) * rstd
b_v = b_kh_hat.to(b_k.dtype) * b_w[None, :].to(b_k.dtype) + \
b_b[None, :].to(b_k.dtype) - b_v.to(b_k.dtype) + tl.trans(b_k)
b_v = tl.where((offs < V)[None, :], b_v * b_w[None, :].to(b_k.dtype), 0.)
b_v2 = rstd * (V * b_v - tl.sum(b_v, axis=1, keep_dims=True) - b_kh_hat.to(b_k.dtype)
* tl.sum(b_v * b_kh_hat.to(b_k.dtype), axis=1, keep_dims=True)) / V
tl.store(p_x, b_kh_hat.to(p_x.dtype.element_ty), boundary_check=(0, 1))
tl.store(p_y, b_v.to(p_y.dtype.element_ty), boundary_check=(0, 1))
tl.store(p_r, rstd.to(p_r.dtype.element_ty), boundary_check=(0, 1))
tl.store(p_v_new, b_v2.to(p_v_new.dtype.element_ty), boundary_check=(0, 1))
b_eta_last = tl.load(p_eta_last)
b_h = b_h - tl.dot(b_eta_last * b_k, b_v2.to(b_k.dtype), allow_tf32=False)
b_hb = b_hb - tl.sum(b_eta_last * b_v2.to(b_k.dtype), axis=0)
@triton.heuristics({
'USE_OFFSETS': lambda args: args['offsets'] is not None,
})
@triton.autotune(
configs=[
triton.Config({}, num_warps=num_warps)
for num_warps in [4]
],
key=['BT', 'BK', 'BV'],
)
@triton.jit(do_not_specialize=['T'])
def chunk_ttt_linear_bwd_kernel_dv_local(
q,
k,
eta,
do,
dv,
offsets,
indices,
scale,
T,
H: tl.constexpr,
K: tl.constexpr,
V: tl.constexpr,
BT: tl.constexpr,
BK: tl.constexpr,
BV: tl.constexpr,
USE_OFFSETS: tl.constexpr,
HEAD_FIRST: tl.constexpr,
):
i_t, i_bh = tl.program_id(0), tl.program_id(1)
i_b, i_h = i_bh // H, i_bh % H
if USE_OFFSETS:
i_n, i_t = tl.load(indices + i_t * 2).to(tl.int32), tl.load(indices + i_t * 2 + 1).to(tl.int32)
bos, eos = tl.load(offsets + i_n).to(tl.int32), tl.load(offsets + i_n + 1).to(tl.int32)
T = eos - bos
else:
bos, eos = i_b * T, i_b * T + T
# offset calculation
q += i_bh * T * K if HEAD_FIRST else (bos * H + i_h) * K
k += i_bh * T * K if HEAD_FIRST else (bos * H + i_h) * K
eta += (i_bh * T) if HEAD_FIRST else (bos * H + i_h)
do += i_bh * T * V if HEAD_FIRST else (bos * H + i_h) * V
dv += i_bh * T * V if HEAD_FIRST else (bos * H + i_h) * V
stride_qk = K if HEAD_FIRST else H*K
stride_vo = V if HEAD_FIRST else H*V
stride_eta = 1 if HEAD_FIRST else H
b_A = tl.zeros([BT, BT], dtype=tl.float32)
for i_k in range(tl.cdiv(K, BK)):
p_k = tl.make_block_ptr(k, (T, K), (stride_qk, 1), (i_t * BT, i_k * BK), (BT, BK), (1, 0))
p_q = tl.make_block_ptr(q, (K, T), (1, stride_qk), (i_k * BK, i_t * BT), (BK, BT), (0, 1))
b_q = tl.load(p_q, boundary_check=(0, 1))
b_k = tl.load(p_k, boundary_check=(0, 1))
b_A += tl.dot(b_k, b_q)
p_eta = tl.make_block_ptr(eta, (T,), (stride_eta,), (i_t * BT,), (BT,), (0,))
b_eta = tl.load(p_eta, boundary_check=(0,))
mask = (tl.arange(0, BT)[:, None] <= tl.arange(0, BT)[None, :])
b_A = - tl.where(mask, b_A * scale * b_eta[None, :], 0).to(do.dtype.element_ty)
b_Ae = - tl.where(mask, b_eta[None, :], 0).to(do.dtype.element_ty)
for i_v in range(tl.cdiv(V, BV)):
p_do = tl.make_block_ptr(do, (T, V), (stride_vo, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_dv = tl.make_block_ptr(dv, (T, V), (stride_vo, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
b_do = tl.load(p_do, boundary_check=(0, 1))
b_dv = tl.dot(b_A.to(b_do.dtype), b_do) + tl.dot(b_Ae.to(b_do.dtype), b_do)
tl.store(p_dv, b_dv.to(p_dv.dtype.element_ty), boundary_check=(0, 1))
@triton.heuristics({
'USE_FINAL_STATE_GRADIENT': lambda args: args['dht'] is not None,
'USE_FINAL_STATE_GRADIENT_B': lambda args: args['dhbt'] is not None,
'USE_INITIAL_STATE': lambda args: args['dh0'] is not None,
'USE_INITIAL_STATE_B': lambda args: args['dhb0'] is not None,
'USE_OFFSETS': lambda args: args['offsets'] is not None,
})
@triton.autotune(
configs=[
triton.Config({}, num_warps=num_warps)
for num_warps in [2, 4, 8, 16]
],
key=['BT', 'BK', 'BV'],
)
@triton.jit(do_not_specialize=['T'])
def chunk_ttt_linear_bwd_kernel_norm(
q,
k,
v,
v_new,
x,
y,
r,
w,
b,
eta,
h,
dht,
dhbt,
dh0,
dhb0,
do,
dh,
dhb,
dv,
dv_new,
dk,
dw,
db,
offsets,
chunk_offsets,
scale,
T,
H: tl.constexpr,
K: tl.constexpr,
V: tl.constexpr,
BT: tl.constexpr,
BK: tl.constexpr,
BV: tl.constexpr,
USE_FINAL_STATE_GRADIENT: tl.constexpr,
USE_FINAL_STATE_GRADIENT_B: tl.constexpr,
USE_INITIAL_STATE: tl.constexpr,
USE_INITIAL_STATE_B: tl.constexpr,
USE_OFFSETS: tl.constexpr,
HEAD_FIRST: tl.constexpr
):
i_k, i_v, i_nh = tl.program_id(0), tl.program_id(1), tl.program_id(2)
i_n, i_h = i_nh // H, i_nh % H
if USE_OFFSETS:
bos, eos = tl.load(offsets + i_n).to(tl.int32), tl.load(offsets + i_n + 1).to(tl.int32)
T = eos - bos
NT = tl.cdiv(T, BT)
boh = tl.load(chunk_offsets + i_n).to(tl.int32)
else:
bos, eos = i_n * T, i_n * T + T
NT = tl.cdiv(T, BT)
boh = i_n * NT
# [BK, BV]
b_dh = tl.zeros([BK, BV], dtype=tl.float32)
# [BV]
b_dhb = tl.zeros([BV], dtype=tl.float32)
if USE_FINAL_STATE_GRADIENT:
p_dht = tl.make_block_ptr(dht + i_nh * K*V, (K, V), (V, 1), (i_k * BK, i_v * BV), (BK, BV), (1, 0))
b_dh += tl.load(p_dht, boundary_check=(0, 1), padding_option="zero")
if USE_FINAL_STATE_GRADIENT_B:
p_dhbt = tl.make_block_ptr(dhbt + i_nh * V, (V,), (1,), (i_v * BV,), (BV,), (0,))
b_dhb += tl.load(p_dhbt, boundary_check=(0,), padding_option="zero")
# [BV]
offs_v = tl.arange(0, BV)
offs_t = tl.arange(0, BT)
b_w = tl.load(w + i_h * V + offs_v, mask=offs_v < V, other=0.)
b_b = tl.load(b + i_h * V + offs_v, mask=offs_v < V, other=0.)
b_dw = tl.zeros([BV,], dtype=b_w.dtype)
b_db = tl.zeros([BV,], dtype=b_b.dtype)
p_dw = tl.make_block_ptr(dw + i_nh * V, (V,), (1,), (i_v * BV,), (BV,), (0,))
p_db = tl.make_block_ptr(db + i_nh * V, (V,), (1,), (i_v * BV,), (BV,), (0,))
for i_t in range(NT - 1, -1, -1):
if HEAD_FIRST:
p_h = tl.make_block_ptr(h + (i_nh * NT + i_t) * K*V, (V, K), (1, V), (i_v * BV, i_k * BK), (BV, BK), (0, 1))
p_dh = tl.make_block_ptr(dh + (i_nh * NT + i_t) * K*V, (K, V), (V, 1), (i_k * BK, i_v * BV), (BK, BV), (1, 0))
p_dhb = tl.make_block_ptr(dhb + (i_nh * NT + i_t) * V, (V,), (1,), (i_v * BV,), (BV,), (0,))
else:
p_h = tl.make_block_ptr(h + ((boh+i_t) * H + i_h) * K*V, (V, K), (1, V), (i_v * BV, i_k * BK), (BV, BK), (0, 1))
p_dh = tl.make_block_ptr(dh + ((boh+i_t) * H + i_h) * K*V, (K, V), (V, 1), (i_k * BK, i_v * BV), (BK, BV), (1, 0))
p_dhb = tl.make_block_ptr(dhb + ((boh+i_t) * H + i_h) * V, (V,), (1,), (i_v * BV,), (BV,), (0,))
tl.store(p_dh, b_dh.to(p_dh.dtype.element_ty), boundary_check=(0, 1))
tl.store(p_dhb, b_dhb.to(p_dhb.dtype.element_ty), boundary_check=(0,))
if HEAD_FIRST:
p_q = tl.make_block_ptr(q + i_nh * T*K, (K, T), (1, K), (i_k * BK, i_t * BT), (BK, BT), (0, 1))
p_k = tl.make_block_ptr(k + i_nh * T*K, (T, K), (K, 1), (i_t * BT, i_k * BK), (BT, BK), (1, 0))
p_v = tl.make_block_ptr(v + i_nh * T*V, (T, V), (V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_v_new = tl.make_block_ptr(v_new + i_nh * T*V, (T, V), (V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_x = tl.make_block_ptr(x + i_nh * T*V, (T, V), (V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_y = tl.make_block_ptr(y + i_nh * T*V, (T, V), (V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_dv_new = tl.make_block_ptr(dv_new + i_nh * T*V, (T, V), (V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_dv = tl.make_block_ptr(dv + i_nh * T*V, (T, V), (V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_dk = tl.make_block_ptr(dk + i_nh * T*K, (T, K), (K, 1), (i_t * BT, i_k * BK), (BT, BK), (1, 0))
p_do = tl.make_block_ptr(do + i_nh * T*V, (T, V), (V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_r = tl.make_block_ptr(r + i_nh * T, (T, 1), (1, 1), (i_t * BT, 0), (BT, 1), (1, 0))
p_eta_last = eta + i_nh*T + T - 1 if i_t == NT-1 else eta + i_nh*T + i_t*BT + BT - 1
else:
p_q = tl.make_block_ptr(q+(bos*H+i_h)*K, (K, T), (1, H*K), (i_k * BK, i_t * BT), (BK, BT), (0, 1))
p_k = tl.make_block_ptr(k+(bos*H+i_h)*K, (T, K), (H*K, 1), (i_t * BT, i_k * BK), (BT, BK), (1, 0))
p_v = tl.make_block_ptr(v+(bos*H+i_h)*V, (T, V), (H*V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_v_new = tl.make_block_ptr(v_new+(bos*H+i_h)*V, (T, V), (H*V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_x = tl.make_block_ptr(x+(bos*H+i_h)*V, (T, V), (H*V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_y = tl.make_block_ptr(y+(bos*H+i_h)*V, (T, V), (H*V, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_dv_new = tl.make_block_ptr(dv_new+(bos*H+i_h)*V, (T, V), (H*V, 1), (i_t*BT, i_v * BV), (BT, BV), (1, 0))
p_dv = tl.make_block_ptr(dv+(bos*H+i_h)*V, (T, V), (H*V, 1), (i_t*BT, i_v * BV), (BT, BV), (1, 0))
p_dk = tl.make_block_ptr(dk+(bos*H+i_h)*K, (T, K), (H*K, 1), (i_t*BT, i_k * BK), (BT, BK), (1, 0))
p_do = tl.make_block_ptr(do+(bos*H+i_h)*V, (T, V), (H*V, 1), (i_t*BT, i_v * BV), (BT, BV), (1, 0))
p_r = tl.make_block_ptr(r+bos*H+i_h, (T, 1), (H, 1), (i_t*BT, 0), (BT, 1), (1, 0))
p_eta_last = eta+bos*H+i_h + (T-1)*H if i_t == NT-1 else eta+bos*H+i_h + (i_t*BT+BT-1)*H
b_k = tl.load(p_k, boundary_check=(0, 1), padding_option="zero")
b_dv_new = tl.load(p_dv_new, boundary_check=(0, 1), padding_option="zero").to(b_k.dtype)
b_eta_last = tl.load(p_eta_last)
b_dv_new -= tl.dot(b_eta_last * b_k, b_dh.to(b_k.dtype))
b_dv_new -= b_eta_last * b_dhb.to(b_k.dtype)[None, :]
b_v_new = tl.load(p_v_new, boundary_check=(0, 1), padding_option="zero")
b_x = tl.load(p_x, boundary_check=(0, 1), padding_option="zero").to(b_k.dtype)
b_y = tl.load(p_y, boundary_check=(0, 1), padding_option="zero").to(b_k.dtype)
b_rstd = tl.load(p_r, boundary_check=(0, 1), padding_option="zero").to(tl.float32)
b_dy = b_rstd * (b_dv_new * V - tl.sum(b_dv_new, axis=1, keep_dims=True) -
b_x * tl.sum(b_dv_new * b_x, axis=1, keep_dims=True)) / V
b_dx = -b_rstd * (b_dv_new * tl.sum(b_x * b_y, axis=1, keep_dims=True) +
b_y * tl.sum(b_dv_new * b_x, axis=1, keep_dims=True)) / V
b_drstd = tl.sum(b_dv_new.to(b_rstd.dtype) * b_v_new.to(b_rstd.dtype) / b_rstd, axis=1, keep_dims=True)
b_v = tl.load(p_v, boundary_check=(0, 1), padding_option="zero")
b_w = b_w.to(b_k.dtype)
b_b = b_b.to(b_k.dtype)
b_dv = -b_w * b_dy.to(b_k.dtype)
b_dk = b_w * b_dy.to(b_k.dtype)
b_dw += tl.sum(2 * b_w * b_x * b_dy.to(b_k.dtype) +
(b_b - b_v.to(b_k.dtype) + b_k) * b_dy.to(b_k.dtype), axis=0).to(b_dw.dtype)
b_db += tl.sum(b_w * b_dy.to(b_k.dtype), axis=0).to(b_db.dtype)
b_dx = b_dx.to(b_k.dtype) + b_w * b_w * b_dy.to(b_k.dtype)
# d_rstd, dx --> dkh --> dk, dh
b_q = tl.load(p_q, boundary_check=(0, 1), padding_option="zero")
b_h = tl.load(p_h, boundary_check=(0, 1), padding_option="zero")
b_do = tl.load(p_do, boundary_check=(0, 1), padding_option="zero")
b_q = (b_q * scale).to(b_q.dtype)
b_dkh = b_rstd * (V * b_dx - tl.sum(b_dx, axis=1, keep_dims=True) -
b_x * tl.sum(b_x * b_dx, axis=1, keep_dims=True)) / V
b_dkh -= b_rstd * b_rstd * b_drstd * b_x / V
b_dkh = tl.where((offs_v < V)[None, :] * (offs_t < T-i_t*BT)[:, None], b_dkh, 0.)
b_dk += tl.dot(b_dkh, b_h.to(b_dkh.dtype)).to(b_k.dtype)
b_dh += tl.dot(b_q, b_do.to(b_q.dtype)) + tl.dot(tl.trans(b_k).to(b_dkh.dtype), b_dkh)
b_dhb += tl.sum(b_do + b_dkh, axis=0)
b_dh = tl.where((offs_v < V)[None, :], b_dh, 0.)
b_dhb = tl.where((offs_v < V), b_dhb, 0.)
tl.store(p_dv, b_dv.to(p_dv.dtype.element_ty), boundary_check=(0, 1))
tl.store(p_dk, b_dk.to(p_dk.dtype.element_ty), boundary_check=(0, 1))
tl.store(p_dw, b_dw.to(p_dw.dtype.element_ty), boundary_check=(0,))
tl.store(p_db, b_db.to(p_db.dtype.element_ty), boundary_check=(0,))
if USE_INITIAL_STATE:
p_dh0 = tl.make_block_ptr(dh0 + i_nh * K*V, (K, V), (V, 1), (i_k * BK, i_v * BV), (BK, BV), (1, 0))
tl.store(p_dh0, b_dh.to(p_dh0.dtype.element_ty), boundary_check=(0, 1))
if USE_INITIAL_STATE_B:
p_dhb0 = tl.make_block_ptr(dhb0+i_nh*V, (V,), (1,), (i_v * BV,), (BV,), (0,))
tl.store(p_dhb0, b_dhb.to(p_dhb0.dtype.element_ty), boundary_check=(0,))
@triton.heuristics({
'USE_OFFSETS': lambda args: args['offsets'] is not None,
})
@triton.autotune(
configs=[
triton.Config({}, num_warps=num_warps, num_stages=num_stages)
for num_warps in [2, 4, 8]
for num_stages in [2, 3]
],
key=['BT', 'BK', 'BV'],
)
@triton.jit(do_not_specialize=['T'])
def chunk_bwd_kernel_dqke(
q,
k,
v,
e,
h,
do,
dh,
dhb,
dq,
dk,
de,
offsets,
indices,
scale,
T,
B: tl.constexpr,
H: tl.constexpr,
K: tl.constexpr,
V: tl.constexpr,
BT: tl.constexpr,
BK: tl.constexpr,
BV: tl.constexpr,
USE_OFFSETS: tl.constexpr,
HEAD_FIRST: tl.constexpr,
):
i_k, i_t, i_bh = tl.program_id(0), tl.program_id(1), tl.program_id(2)
i_b, i_h = i_bh // H, i_bh % H
if USE_OFFSETS:
i_tg = i_t
i_n, i_t = tl.load(indices + i_t * 2).to(tl.int32), tl.load(indices + i_t * 2 + 1).to(tl.int32)
bos, eos = tl.load(offsets + i_n).to(tl.int32), tl.load(offsets + i_n + 1).to(tl.int32)
T = eos - bos
NT = tl.cdiv(T, BT)
else:
NT = tl.cdiv(T, BT)
i_tg = i_b * NT + i_t
bos, eos = i_b * T, i_b * T + T
# offset calculation
v += i_bh * T * V if HEAD_FIRST else (bos * H + i_h) * V
do += i_bh * T * V if HEAD_FIRST else (bos * H + i_h) * V
h += (i_bh * NT + i_t) * K*V if HEAD_FIRST else (i_tg * H + i_h) * K * V
dh += (i_bh * NT + i_t) * K*V if HEAD_FIRST else (i_tg * H + i_h) * K * V
dhb += (i_bh * NT + i_t) * V if HEAD_FIRST else (i_tg * H + i_h) * V
q += i_bh * T * K if HEAD_FIRST else (bos * H + i_h) * K
k += i_bh * T * K if HEAD_FIRST else (bos * H + i_h) * K
dq += i_bh * T * K if HEAD_FIRST else (bos * H + i_h) * K
dk += i_bh * T * K if HEAD_FIRST else (bos * H + i_h) * K
e += i_bh * T if HEAD_FIRST else (bos * H + i_h)
de += i_bh * T if HEAD_FIRST else (bos * H + i_h)
stride_qk = K if HEAD_FIRST else H*K
stride_vo = V if HEAD_FIRST else H*V
stride_e = 1 if HEAD_FIRST else H
b_dq = tl.zeros([BT, BK], dtype=tl.float32)
b_dk = tl.zeros([BT, BK], dtype=tl.float32)
b_ds = tl.zeros([BT, BT], dtype=tl.float32)
b_de = tl.zeros([BT,], dtype=tl.float32)
p_k = tl.make_block_ptr(k, (T, K), (stride_qk, 1), (i_t * BT, i_k * BK), (BT, BK), (1, 0))
b_k = tl.load(p_k, boundary_check=(0, 1))
p_e_last = (e + (i_t*BT+BT-1)*stride_e) if (i_t*BT+BT) <= T else (e + (T-1)*stride_e)
i_last = (BT-1) if (i_t*BT+BT) <= T else (T % BT-1)
mask = (tl.arange(0, BT) == i_last)
b_e_last = tl.load(p_e_last)
for i_v in range(tl.cdiv(V, BV)):
p_v = tl.make_block_ptr(v, (T, V), (stride_vo, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_do = tl.make_block_ptr(do, (T, V), (stride_vo, 1), (i_t * BT, i_v * BV), (BT, BV), (1, 0))
p_h = tl.make_block_ptr(h, (V, K), (1, V), (i_v * BV, i_k * BK), (BV, BK), (0, 1))
p_dh = tl.make_block_ptr(dh, (V, K), (1, V), (i_v * BV, i_k * BK), (BV, BK), (0, 1))
p_dhb = tl.make_block_ptr(dhb, (V,), (1,), (i_v * BV,), (BV,), (0,))
# [BT, BV]
b_v = tl.load(p_v, boundary_check=(0, 1))
b_do = tl.load(p_do, boundary_check=(0, 1))
# [BV, BK]
b_h = tl.load(p_h, boundary_check=(0, 1))
b_dh = tl.load(p_dh, boundary_check=(0, 1))
# [BV]
b_dhb = tl.load(p_dhb, boundary_check=(0,))
# [BT, BV] @ [BV, BT] -> [BT, BT]
b_ds += tl.dot(b_do, tl.trans(b_v))
# [BT, BV] @ [BV, BK] -> [BT, BK]
b_dq += tl.dot(b_do, b_h.to(b_do.dtype))
# [BT, BV] @ [BV, BK] -> [BT, BK]
b_dk -= b_e_last * tl.dot(b_v, b_dh.to(b_v.dtype))
b_de -= mask * tl.sum(tl.trans(b_dh) * tl.dot(tl.trans(b_k), b_v.to(b_k.dtype)))
b_de -= mask * tl.sum(b_dhb * tl.sum(b_v, axis=0).to(b_k.dtype))
o_i = tl.arange(0, BT)
p_q = tl.make_block_ptr(q, (T, K), (stride_qk, 1), (i_t * BT, i_k * BK), (BT, BK), (1, 0))
p_e = tl.make_block_ptr(e, (T,), (stride_e,), (i_t * BT,), (BT,), (0,))
b_q = tl.load(p_q, boundary_check=(0, 1))
b_e = tl.load(p_e, boundary_check=(0,))
p_dq = tl.make_block_ptr(dq, (T, K), (stride_qk, 1), (i_t * BT, i_k * BK), (BT, BK), (1, 0))
p_dk = tl.make_block_ptr(dk, (T, K), (stride_qk, 1), (i_t * BT, i_k * BK), (BT, BK), (1, 0))
p_de = tl.make_block_ptr(de, (T,), (stride_e,), (i_t * BT,), (BT,), (0,))
b_ds = tl.where(o_i[:, None] >= o_i[None, :], b_ds, 0)
b_ds = b_ds.to(b_k.dtype)
b_dq -= tl.dot(b_ds, b_k) * b_e[:, None]
b_dk -= tl.dot(tl.trans(b_ds), b_q * b_e[:, None]) * scale
b_de -= tl.sum(scale * tl.dot(b_ds, b_k) * b_q, axis=1)
b_de -= tl.sum(b_ds, axis=1)
b_dq *= scale
tl.store(p_dq, b_dq.to(p_dq.dtype.element_ty), boundary_check=(0, 1))
tl.store(p_dk, b_dk.to(p_dk.dtype.element_ty), boundary_check=(0, 1))
tl.store(p_de, b_de.to(p_de.dtype.element_ty), boundary_check=(0,))
def chunk_ttt_linear_fwd_h(
k: torch.Tensor,
v: torch.Tensor,
w: torch.Tensor,
b: torch.Tensor,
eta: torch.Tensor,
eps: float,
initial_state: Optional[torch.Tensor] = None,
initial_state_bias: Optional[torch.Tensor] = None,
output_final_state: bool = False,
offsets: Optional[torch.LongTensor] = None,
indices: Optional[torch.LongTensor] = None,
head_first: bool = True,
chunk_size: int = 16,
) -> Tuple[torch.Tensor, torch.Tensor]:
if head_first:
B, H, T, K, V = *k.shape, v.shape[-1]
else:
B, T, H, K, V = *k.shape, v.shape[-1]
BT = chunk_size
# N: the actual number of sequences in the batch with either equal or variable lengths
if offsets is None:
N, NT, chunk_offsets = B, triton.cdiv(T, BT), None
else:
N, NT, chunk_offsets = len(offsets) - 1, len(indices), prepare_chunk_offsets(offsets, BT)
BK = triton.next_power_of_2(K)
BV = triton.next_power_of_2(V)
assert max(BK, BV) <= 128, "current kernel does not support head dimension larger than 128."
NK = triton.cdiv(K, BK)
NV = triton.cdiv(V, BV)
assert NK == 1, 'NK > 1 is not supported because it involves time-consuming synchronization'
assert NV == 1, 'NV > 1 is not supported by TTT update rule.'
if head_first:
h = k.new_empty(B, H, NT, K, V)
hb = k.new_empty(B, H, NT, 1, V)
else:
h = k.new_empty(B, NT, H, K, V)
hb = k.new_empty(B, NT, H, 1, V)
final_state = k.new_empty(N, H, K, V, dtype=torch.float32) if output_final_state else None
final_state_bias = k.new_empty(N, H, 1, V, dtype=torch.float32) if output_final_state else None
v_new = torch.empty_like(v)
grid = (NK, NV, N * H)
chunk_ttt_linear_fwd_kernel_h[grid](
k=k,
v=v,
v_new=v_new,
eta=eta,
w=w,
b=b,
eps=eps,
h=h,
hb=hb,
h0=initial_state,
hb0=initial_state_bias,
ht=final_state,
hbt=final_state_bias,
offsets=offsets,
chunk_offsets=chunk_offsets,
T=T,
H=H,
K=K,
V=V,
BT=BT,
BK=BK,
BV=BV,
NT=NT,
HEAD_FIRST=head_first
)
return h, hb, v_new, final_state, final_state_bias
def chunk_ttt_linear_fwd_o(
q: torch.Tensor,
k: torch.Tensor,
v: torch.Tensor,
eta: torch.Tensor,
h: torch.Tensor,
hb: torch.Tensor,
scale: Optional[float] = None,
offsets: Optional[torch.LongTensor] = None,
indices: Optional[torch.LongTensor] = None,
head_first: bool = True,
chunk_size: int = 64
) -> torch.Tensor:
if head_first:
B, H, T, K, V = *q.shape, v.shape[-1]
else:
B, T, H, K, V = *q.shape, v.shape[-1]
if scale is None:
scale = k.shape[-1] ** -0.5
BT = chunk_size
NT = triton.cdiv(T, BT) if offsets is None else len(indices)
BK = triton.next_power_of_2(K)
BV = triton.next_power_of_2(V)
NK = triton.cdiv(K, BK)
NV = triton.cdiv(V, BV)
assert NK == 1, 'NK > 1 is not supported because it involves time-consuming synchronization'
assert NV == 1, 'NV > 1 is not supported by TTT update rule.'
o = torch.empty_like(v)
grid = (NV, NT, B * H)
chunk_ttt_linear_fwd_kernel_o[grid](
q,
k,
v,
eta,
h,
hb,
o,
offsets,
indices,
scale,
T=T,
H=H,
K=K,
V=V,
BT=BT,
BK=BK,
BV=BV,
HEAD_FIRST=head_first
)
return o
def chunk_ttt_linear_bwd_h(
k: torch.Tensor,
v: torch.Tensor,
w: torch.Tensor,
b: torch.Tensor,
eta: torch.Tensor,
eps: float,
initial_state: Optional[torch.Tensor] = None,
initial_state_bias: Optional[torch.Tensor] = None,
offsets: Optional[torch.LongTensor] = None,
indices: Optional[torch.LongTensor] = None,
head_first: bool = True,
chunk_size: int = 16,
) -> Tuple[torch.Tensor, torch.Tensor]:
if head_first:
B, H, T, K, V = *k.shape, v.shape[-1]
else:
B, T, H, K, V = *k.shape, v.shape[-1]
BT = chunk_size
# N: the actual number of sequences in the batch with either equal or variable lengths
if offsets is None:
N, NT, chunk_offsets = B, triton.cdiv(T, BT), None
else:
N, NT, chunk_offsets = len(offsets) - 1, len(indices), prepare_chunk_offsets(offsets, BT)
BK = triton.next_power_of_2(K)
BV = triton.next_power_of_2(V)
assert max(BK, BV) <= 128, "current kernel does not support head dimension larger than 128."
NK = triton.cdiv(K, BK)
NV = triton.cdiv(V, BV)
assert NK == 1, 'NK > 1 is not supported because it involves time-consuming synchronization'
assert NV == 1, 'NV > 1 is not supported by TTT update rule.'
if head_first:
h = k.new_empty(B, H, NT, K, V)
rstd = v.new_empty(B, H, T, 1, dtype=torch.float32)
else:
h = k.new_empty(B, NT, H, K, V)
rstd = v.new_empty(B, T, H, 1, dtype=torch.float32)
x = torch.empty_like(v)
y = torch.empty_like(v)
v_new = torch.empty_like(v)
grid = (NK, NV, N * H)
chunk_ttt_linear_bwd_kernel_h[grid](
k=k,
v=v,
v_new=v_new,
eta=eta,
w=w,
b=b,
eps=eps,
h=h,
h0=initial_state,
hb0=initial_state_bias,
x=x,
y=y,
r=rstd,
offsets=offsets,
chunk_offsets=chunk_offsets,
T=T,
H=H,
K=K,
V=V,
BT=BT,
BK=BK,
BV=BV,
NT=NT,
HEAD_FIRST=head_first
)
return h, v_new, x, y, rstd
def chunk_ttt_linear_bwd_dv_local(
q: torch.Tensor,
k: torch.Tensor,
eta: torch.Tensor,
do: torch.Tensor,
scale: float,
offsets: Optional[torch.LongTensor] = None,
indices: Optional[torch.LongTensor] = None,
head_first: bool = True,
chunk_size: int = 16
) -> torch.Tensor:
if head_first:
B, H, T, K, V = *k.shape, do.shape[-1]
else:
B, T, H, K, V = *k.shape, do.shape[-1]
BT = chunk_size
NT = triton.cdiv(T, BT) if offsets is None else len(indices)
BK = min(triton.next_power_of_2(K), 128)
BV = min(triton.next_power_of_2(V), 128)
dv = torch.empty_like(do)
grid = (NT, B * H)
chunk_ttt_linear_bwd_kernel_dv_local[grid](
q,
k,
eta,
do,
dv,
offsets,
indices,
scale,
T=T,
H=H,
K=K,
V=V,
BT=BT,
BK=BK,
BV=BV,
HEAD_FIRST=head_first
)
return dv
def chunk_ttt_linear_bwd_norm(
q: torch.Tensor, # [B, H, L, D]
k: torch.Tensor, # [B, H, L, D]
v: torch.Tensor, # [B, H, L, D]
v_new: torch.Tensor, # [B, H, L, D]
x: torch.Tensor, # [B, H, L, D]
y: torch.Tensor, # [B, H, L, D]
rstd: torch.Tensor, # [B, H, L, 1]
w: torch.Tensor, # [H, D]
b: torch.Tensor, # [H, D]
eta: torch.Tensor, # [B, H, L, 1]
h0: torch.Tensor, # [B, H, D, D]
hb0: torch.Tensor, # [B, H, 1, D]
h: torch.Tensor, # [B, H, NT, D, D]
dht: Optional[torch.Tensor], # [B, H, D, D]
dhbt: Optional[torch.Tensor], # [B, H, 1, D]
dv_new: Optional[torch.Tensor], # [B, H, L, D]
do: torch.Tensor, # [B, H, L, D]
scale: float,
offsets: Optional[torch.LongTensor] = None,
indices: Optional[torch.LongTensor] = None,
head_first: bool = True,
chunk_size: int = 16
) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor]:
# torch implementation of `dkh, dw, db, dk, dv` for LN^2
assert offsets is None, "bwd of varlen is not implemented yet."
if head_first:
B, H, T, K, V = *q.shape, do.shape[-1]
else:
B, T, H, K, V = *q.shape, do.shape[-1]
BT = chunk_size
if offsets is None:
N, NT, chunk_offsets = B, triton.cdiv(T, BT), None
else:
N, NT, chunk_offsets = len(offsets) - 1, len(indices), prepare_chunk_offsets(offsets, BT)
BK = triton.next_power_of_2(K)
BV = triton.next_power_of_2(V)
NK = triton.cdiv(K, BK)
NV = triton.cdiv(V, BV)
assert NK == 1, 'NK > 1 is not supported by TTT.'
assert NV == 1, 'NV > 1 is not supported by TTT.'
if head_first:
dh = q.new_empty(B, H, NT, K, V)
dhb = q.new_empty(B, H, NT, 1, V)
else:
dh = q.new_empty(B, NT, H, K, V)
dhb = q.new_empty(B, NT, H, 1, V)
dh0 = torch.empty_like(h0, dtype=torch.float32) if h0 is not None else None
dhb0 = torch.empty_like(hb0, dtype=torch.float32) if hb0 is not None else None
dv = torch.empty_like(v)
dk = torch.empty_like(k)
dw = w.new_empty(B, H, V)
db = b.new_empty(B, H, V)
grid = (NK, NV, N * H)
chunk_ttt_linear_bwd_kernel_norm[grid](
q=q,
k=k,
v=v,
v_new=v_new,
x=x,
y=y,
r=rstd,
w=w,
b=b,
eta=eta,
h=h,
dht=dht,
dhbt=dhbt,
dh0=dh0,
dhb0=dhb0,
do=do,
dh=dh,
dhb=dhb,
dv=dv,
dv_new=dv_new,
dk=dk,
dw=dw,
db=db,
offsets=offsets,
chunk_offsets=chunk_offsets,
scale=scale,
T=T,
H=H,
K=K,
V=V,
BT=BT,
BK=BK,
BV=BV,
HEAD_FIRST=head_first
)
dw = dw.sum(dim=0)
db = db.sum(dim=0)
return dh, dhb, dh0, dhb0, dv, dk, dw, db
def chunk_ttt_linear_bwd_norm_ref(
q: torch.Tensor, # [B, H, L, D]
k: torch.Tensor, # [B, H, L, D]
v: torch.Tensor, # [B, H, L, D]
v_new: torch.Tensor, # [B, H, L, D]
kh: torch.Tensor, # [B, H, L, D]
y: torch.Tensor, # [B, H, L, D]
w: torch.Tensor, # [H, D]
b: torch.Tensor, # [H, D]
eta: torch.Tensor, # [B, H, L, 1]
h0: torch.Tensor, # [B, H, D, D]
h: torch.Tensor, # [B, H, NT, D, D]
dht: Optional[torch.Tensor], # [B, H, D, D]
dv_new: Optional[torch.Tensor], # [B, H, L, D]
do: torch.Tensor, # [B, H, L, D]
scale: float,
eps: float,
offsets: Optional[torch.LongTensor] = None,
indices: Optional[torch.LongTensor] = None,
head_first: bool = True,
chunk_size: int = 16
) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor]:
# torch implementation of `dkh, dw, db, dk, dv` for LN^2
assert offsets is None, "bwd of varlen is not implemented yet."
if head_first:
B, H, T, K, V = *q.shape, do.shape[-1]
else:
B, T, H, K, V = *q.shape, do.shape[-1]
# [B, L, H, D] -> [B, H, L, D]
q, k, v, v_new, kh, y, h, eta, dv_new, do = [
x.transpose(1, 2) for x in
[q, k, v, v_new, kh, y, h, eta, dv_new, do]
]
BT = chunk_size
NT = triton.cdiv(T, BT) if offsets is None else len(indices)
pad_len = (BT - (T % BT)) % BT
if pad_len > 0:
q, k, v, v_new, kh, y, eta, dv_new, do = [
F.pad(x, (0, 0, 0, pad_len)) for x in
[q, k, v, v_new, kh, y, eta, dv_new, do]
]
eta[:, :, -1, :] = eta[:, :, -(pad_len+1), :]
# [NT, B, H, BT, D]
q, k, v, v_new, kh, y, eta, dv_new, do = [
x.reshape(B, H, NT, BT, -1).permute(2, 0, 1, 3, 4) for x in
[q, k, v, v_new, kh, y, eta, dv_new, do]
]
h = h.permute(2, 0, 1, 3, 4)
# allocate
dh = q.new_zeros(NT, B, H, K, V)
dv = torch.zeros_like(v)
dk = torch.zeros_like(k)
dw = torch.zeros_like(w)
db = torch.zeros_like(b)
# recurrent state
b_dh = dht if dht is not None else torch.zeros_like(dh[0])
b_dh = b_dh.to(torch.float32)
# [H, 1, D]
_w = w.reshape(H, 1, V).to(torch.float32)
_b = b.reshape(H, 1, V).to(torch.float32)
# d_state passing
for i_t in range(NT - 1, -1, -1):
dh[i_t] = b_dh.to(dh.dtype)
# [B, H, BT, D]
_q, _k, _v, _v_new, _kh, _y, _h, _eta, _dv_new, _do = [
x[i_t].to(torch.float32) for x in
(q, k, v, v_new, kh, y, h, eta, dv_new, do)
]
_dv_new -= (_eta[:, :, -1, :, None] * _k) @ b_dh
mean = _kh.mean(dim=-1, keepdim=True)
var = _kh.var(dim=-1, unbiased=False, keepdim=True).to(torch.float32)
rstd = 1 / torch.sqrt(var + eps).to(torch.float32)
x = (_kh - mean) * rstd
# [B, H, BT, D]
dy = rstd * (_dv_new*V - _dv_new.sum(dim=-1, keepdim=True) - x*(x*_dv_new).sum(dim=-1, keepdim=True)) / V
dx = -rstd * (_dv_new*(x*_y).sum(dim=-1, keepdim=True) + _y*(x*_dv_new).sum(dim=-1, keepdim=True)) / V
d_rstd = (_dv_new * _v_new / rstd).sum(dim=-1, keepdim=True)
dv[i_t] = (-_w*dy).to(dv.dtype)
dk[i_t] += (_w*dy).to(dk.dtype)
dw += (2*_w*x*dy+(_b-_v+_k)*dy).sum(dim=(0, 2)).to(dw.dtype)
db += (_w*dy).sum(dim=(0, 2)).to(db.dtype)
dx += _w*_w*dy
# d_rstd, dx --> dkh --> dk, dh
dkh = rstd * (V * dx - dx.sum(dim=-1, keepdim=True) - x * (x * dx).sum(dim=-1, keepdim=True)) / V
dkh -= rstd**2 * d_rstd * x / V
dk[i_t] += (dkh @ _h.transpose(-2, -1)).to(dk.dtype)
b_dh += (_q.transpose(-2, -1) * scale) @ _do + _k.transpose(-2, -1) @ dkh
dh0 = b_dh.to(torch.float32) if h0 is not None else None
# [NT, B, H, BT, D] -> [B, H, T, D]
dv = dv.permute(1, 2, 0, 3, 4).reshape(B, H, -1, V)[:, :, :T, :]
dk = dk.permute(1, 2, 0, 3, 4).reshape(B, H, -1, K)[:, :, :T, :]
# [B, H, NT, D, D]
dh = dh.permute(1, 2, 0, 3, 4)
if not head_first:
dv, dk, dh = [x.transpose(1, 2) for x in (dv, dk, dh)]
dh, dv, dk, dw, db = [x.contiguous() for x in (dh, dv, dk, dw, db)]
dh0 = dh0.contiguous() if h0 is not None else None
return dh, dh0, dv, dk, dw, db
def chunk_ttt_linear_bwd_dqke(
q: torch.Tensor,
k: torch.Tensor,
v: torch.Tensor,
eta: torch.Tensor,
h: torch.Tensor,
do: torch.Tensor,
dh: torch.Tensor,
dhb: torch.Tensor,
scale: float,
offsets: Optional[torch.LongTensor] = None,
indices: Optional[torch.LongTensor] = None,
head_first: bool = True,
chunk_size: int = 16,
) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor]:
if head_first:
B, H, T, K, V = *k.shape, v.shape[-1]
else:
B, T, H, K, V = *k.shape, v.shape[-1]
BT = chunk_size
NT = triton.cdiv(T, BT) if offsets is None else len(indices)
BK = triton.next_power_of_2(K)
BV = min(triton.next_power_of_2(V), 64)
NK = triton.cdiv(K, BK)
assert NK == 1, "NK > 1 is not supported."
dq = torch.empty_like(q)
dk = torch.empty_like(k)
de = torch.empty_like(eta)
grid = (NK, NT, B * H)
chunk_bwd_kernel_dqke[grid](
q=q,
k=k,
v=v,
e=eta,
h=h,
do=do,
dh=dh,
dhb=dhb,
dq=dq,
dk=dk,
de=de,
offsets=offsets,
indices=indices,
scale=scale,
B=B,
T=T,
H=H,
K=K,
V=V,
BT=BT,
BK=BK,
BV=BV,
HEAD_FIRST=head_first
)
return dq, dk, de
def chunk_ttt_linear_fwd(
q: torch.Tensor,
k: torch.Tensor,
v: torch.Tensor,
w: torch.Tensor,
b: torch.Tensor,
eta: torch.Tensor,
scale: float,
eps: float,
initial_state: torch.Tensor,
initial_state_bias: torch.Tensor,
output_final_state: bool,
offsets: Optional[torch.LongTensor] = None,
indices: Optional[torch.LongTensor] = None,
head_first: bool = True,
BT: int = 16
):
h, hb, v_new, final_state, final_state_bias = chunk_ttt_linear_fwd_h(
k=k,
v=v,
w=w,
b=b,
eta=eta,
eps=eps,
initial_state=initial_state,
initial_state_bias=initial_state_bias,
output_final_state=output_final_state,
offsets=offsets,
indices=indices,
head_first=head_first,
chunk_size=BT
)
o = chunk_ttt_linear_fwd_o(
q=q,
k=k,
v=v_new,
eta=eta,
h=h,
hb=hb,
scale=scale,
offsets=offsets,
indices=indices,
head_first=head_first,
chunk_size=BT
)
return o, final_state, final_state_bias
def chunk_ttt_linear_bwd(
q: torch.Tensor,
k: torch.Tensor,
v: torch.Tensor,
w: torch.Tensor,
b: torch.Tensor,
eta: torch.Tensor,
scale: float,
eps: float,
do: torch.Tensor,
dht: torch.Tensor,
dhbt: torch.Tensor,
BT: int = 16,
initial_state: torch.Tensor = None,
initial_state_bias: torch.Tensor = None,
offsets: Optional[torch.LongTensor] = None,
indices: Optional[torch.LongTensor] = None,
head_first: bool = True
):
h, v_new, x, y, rstd = chunk_ttt_linear_bwd_h(
k=k,
v=v,
w=w,
b=b,
eta=eta,
eps=eps,
initial_state=initial_state,
initial_state_bias=initial_state_bias,
offsets=offsets,
indices=indices,
head_first=head_first,
chunk_size=BT
)
dv_new = chunk_ttt_linear_bwd_dv_local(
q=q,
k=k,
eta=eta,
do=do,
scale=scale,
offsets=offsets,
indices=indices,
head_first=head_first,
chunk_size=BT
)
dh, dhb, dh0, dhb0, dv, dk, dw, db = chunk_ttt_linear_bwd_norm(
q=q,
k=k,
v=v,
v_new=v_new,
x=x,
y=y,
rstd=rstd,
w=w,
b=b,
eta=eta,
h0=initial_state,
hb0=initial_state_bias,
h=h,
dht=dht,
dhbt=dhbt,
dv_new=dv_new,
do=do,
scale=scale,
offsets=offsets,
indices=indices,
head_first=head_first,
chunk_size=BT
)
dq, dk2, de = chunk_ttt_linear_bwd_dqke(
q=q,
k=k,
v=v_new,
eta=eta,
h=h,
do=do,
dh=dh,
dhb=dhb,
scale=scale,
offsets=offsets,
indices=indices,
head_first=head_first,
chunk_size=BT
)
dk.add_(dk2)
return dq, dk, dv, de, dw, db, dh0, dhb0
class ChunkTTTLinearFunction(torch.autograd.Function):
@staticmethod
@input_guard
@autocast_custom_fwd
def forward(ctx, q, k, v, w, b, BT, eta, scale, eps, initial_state,
initial_state_bias, output_final_state, offsets, head_first):
# 2-d indices denoting the offsets of chunks in each sequence
# for example, if the passed `offsets` is [0, 100, 356] and `chunk_size` is 64,
# then there are 2 and 4 chunks in the 1st and 2nd sequences respectively, and `indices` will be
# [[0, 0], [0, 1], [1, 0], [1, 1], [1, 2], [1, 3]]
indices = prepare_chunk_indices(offsets, BT) if offsets is not None else None
o, final_state, final_state_bias = chunk_ttt_linear_fwd(
q=q,
k=k,
v=v,
w=w,
b=b,
eta=eta,
scale=scale,
eps=eps,
BT=BT,
initial_state=initial_state,
initial_state_bias=initial_state_bias,
output_final_state=output_final_state,
offsets=offsets,
indices=indices,
head_first=head_first,
)
ctx.save_for_backward(q, k, v, eta, w, b, initial_state, initial_state_bias)
ctx.BT = BT
ctx.scale = scale
ctx.eps = eps
ctx.offsets = offsets
ctx.indices = indices
ctx.head_first = head_first
return o.to(q.dtype), final_state, final_state_bias
@staticmethod
@input_guard
@autocast_custom_bwd
def backward(ctx, do, dht, dhbt):
q, k, v, eta, w, b, initial_state, initial_state_bias = ctx.saved_tensors
dq, dk, dv, de, dw, db, dh0, dhb0 = chunk_ttt_linear_bwd(
q=q,
k=k,
v=v,
w=w,
b=b,
eta=eta,
scale=ctx.scale,
eps=ctx.eps,
do=do,
dht=dht,
dhbt=dhbt,
BT=ctx.BT,
initial_state=initial_state,
initial_state_bias=initial_state_bias,
offsets=ctx.offsets,
indices=ctx.indices,
head_first=ctx.head_first
)
return dq.to(q), dk.to(k), dv.to(v), dw.to(w), db.to(b), None, de.to(eta), None, None, dh0, dhb0, None, None, None
def norm_residual(x, weight, bias, eps, head_first):
# GroupNorm and Residual
if head_first:
B, H, T, D = x.shape
x = x.transpose(1, 2)
x += group_norm(
x.reshape(B, T, -1).clone(),
weight=weight.reshape(-1).clone(),
bias=bias.reshape(-1).clone(),
eps=eps,
num_groups=H,
).reshape(x.shape)
x = x.transpose(1, 2)
else:
B, T, H, D = x.shape
x += group_norm(
x.reshape(B, T, -1).clone(),
weight=weight.reshape(-1).clone(),
bias=bias.reshape(-1).clone(),
eps=eps,
num_groups=H,
).reshape(x.shape)
return x
def chunk_ttt_linear(
q: torch.Tensor,
k: torch.Tensor,
v: torch.Tensor,
w: torch.Tensor,
b: torch.Tensor,
eta: torch.Tensor,
scale: float = None,
eps: float = 1e-6,
chunk_size: int = 16,
initial_state: torch.Tensor = None,
initial_state_bias: torch.Tensor = None,
output_final_state: bool = False,
cu_seqlens: Optional[torch.LongTensor] = None,
head_first: bool = True,
):
r"""
Args:
q (torch.Tensor):
queries of shape `(B, H, T, K)`
k (torch.Tensor):
keys of shape `(B, H, T, K)`
v (torch.Tensor):
values of shape `(B, H, T, V)`
w (torch.Tensor):
layer norm weight of shape `(H, V)`
b (torch.Tensor):
layer norm bias of shape `(H, V)`
eta (torch.Tensor):
Learning rate for hidden state, of shape `(B, H, T, 1)`.
scale (Optional[int]):
Scale factor for the RetNet attention scores.
If not provided, it will default to `1 / sqrt(K)`. Default: `None`.
chunk_size (int):
chunk size. Default: `16`.
initial_state (Optional[torch.Tensor]):
Initial state of shape `(B, H, K, V)`. Default: `None`.
initial_state_bias (Optional[torch.Tensor]):
Initial state bias of shape `(B, H, 1, V)`. Default: `None`.
output_final_state (Optional[bool]):
Whether to output the final state of shape `(B, H, K, V)`. Default: `False`.
cu_seqlens (torch.LongTensor):
Cumulative sequence lengths of shape `[N+1]` used for variable-length training,
consistent with the FlashAttention API.
head_first (Optional[bool]):
Whether the inputs are in the head-first format, which is not supported for variable-length inputs.
Default: `True`.
Returns:
o (torch.Tensor):
Outputs of shape `[B, H, T, V]`
final_state (torch.Tensor):
Final state of shape `[B, H, K, V]` if `output_final_state=True` else `None`
"""
assert q.dtype == k.dtype == v.dtype
assert k.shape[-1] == v.shape[-1], "DK must equal to DV."
if isinstance(eta, float):
eta = torch.full_like(q[:, :, :, :1], eta)
if cu_seqlens is not None:
if q.shape[0] != 1:
raise ValueError(f"The batch size is expected to be 1 rather than {q.shape[0]} when using `cu_seqlens`."
f"Please flatten variable-length inputs before processing.")
if head_first:
raise RuntimeError("Sequences with variable lengths are not supported for head-first mode")
if initial_state is not None and initial_state.shape[0] != len(cu_seqlens) - 1:
raise ValueError(f"The number of initial states is expected to be equal to the number of input sequences, "
f"i.e., {len(cu_seqlens) - 1} rather than {initial_state.shape[0]}.")
if scale is None:
scale = k.shape[-1] ** -0.5
else:
assert scale > 0, "Scale must be positive."
o, final_state, final_state_bias = ChunkTTTLinearFunction.apply(
q,
k,
v,
w,
b,
chunk_size,
eta,
scale,
eps,
initial_state,
initial_state_bias,
output_final_state,
cu_seqlens,
head_first,
)
o = norm_residual(o, w, b, eps, head_first)
return o, final_state, final_state_bias