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15c2580 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 | """Local editable copy of vLLM fused_moe_kernel_gptq_awq (int4 W4A16 MoE GEMM).
Extracted verbatim from vllm/model_executor/layers/fused_moe/fused_moe.py for
PerfSkills kernel-level optimization. Optimize the @triton.jit bodies here.
"""
from vllm.triton_utils import tl, triton
@triton.jit
def write_zeros_to_output(
c_ptr,
stride_cm,
stride_cn,
pid_n,
N,
offs_token,
token_mask,
BLOCK_SIZE_M,
BLOCK_SIZE_N,
compute_type,
):
accumulator = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=compute_type)
offs_cn = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
c_ptrs = c_ptr + stride_cm * offs_token[:, None] + stride_cn * offs_cn[None, :]
c_mask = token_mask[:, None] & (offs_cn[None, :] < N)
tl.store(c_ptrs, accumulator, mask=c_mask)
@triton.jit
def fused_moe_kernel_gptq_awq(
# Pointers to matrices
a_ptr,
b_ptr,
c_ptr,
b_scale_ptr,
b_zp_ptr,
topk_weights_ptr,
sorted_token_ids_ptr,
expert_ids_ptr,
num_tokens_post_padded_ptr,
# Matrix dimensions
N: tl.constexpr,
K: tl.constexpr,
EM,
num_valid_tokens,
# The stride variables represent how much to increase the ptr by when
# moving by 1 element in a particular dimension. E.g. `stride_am` is
# how much to increase `a_ptr` by to get the element one row down
# (A has M rows).
stride_am,
stride_ak,
stride_be,
stride_bk,
stride_bn,
stride_cm,
stride_cn,
stride_bse,
stride_bsk,
stride_bsn,
stride_bze,
stride_bzk,
stride_bzn,
block_k_diviable: tl.constexpr,
group_size: tl.constexpr,
# Meta-parameters
BLOCK_SIZE_M: tl.constexpr,
BLOCK_SIZE_N: tl.constexpr,
BLOCK_SIZE_K: tl.constexpr,
GROUP_SIZE_M: tl.constexpr,
SPLIT_K: tl.constexpr,
MUL_ROUTED_WEIGHT: tl.constexpr,
top_k: tl.constexpr,
compute_type: tl.constexpr,
has_zp: tl.constexpr,
use_int4_w4a16: tl.constexpr,
use_int8_w8a16: tl.constexpr,
):
"""
Implements the fused computation for a Mixture of Experts (MOE) using
token and expert matrices.
Key Parameters:
- A: The input tensor representing tokens with shape (*, K), where '*' can
be any shape representing batches and K is the feature dimension of
each token.
- B: The stacked MOE weight tensor with shape (E, N, K), where E is
the number of experts, K is the input feature dimension, and N is
the output feature dimension.
- C: The output cache tensor with shape (M, topk, N), where M is the
total number of tokens post padding, topk is the number of times
each token is repeated, and N is the output feature dimension.
- sorted_token_ids: A tensor containing the sorted indices of tokens,
repeated topk times and arranged by the expert index they are
assigned to.
- expert_ids: A tensor containing the indices of the expert for each
block. It determines which expert matrix from B should be used for
each block in A.
This kernel performs the multiplication of a token by its corresponding
expert matrix as determined by `expert_ids`. The sorting of
`sorted_token_ids` by expert index and padding ensures divisibility by
BLOCK_SIZE_M, which is necessary to maintain consistency in block matrix
multiplication across different blocks processed by the same expert.
"""
# -----------------------------------------------------------
# Map program ids `pid` to the block of C it should compute.
# This is done in a grouped ordering to promote L2 data reuse.
pid = tl.program_id(axis=0)
num_pid_m = tl.cdiv(EM, BLOCK_SIZE_M)
num_pid_n = tl.cdiv(N, BLOCK_SIZE_N)
num_pid_in_group = GROUP_SIZE_M * num_pid_n
group_id = pid // num_pid_in_group
first_pid_m = group_id * GROUP_SIZE_M
group_size_m = min(num_pid_m - first_pid_m, GROUP_SIZE_M)
pid_m = first_pid_m + ((pid % num_pid_in_group) % group_size_m)
pid_n = (pid % num_pid_in_group) // group_size_m
# ----------------------------------------------------------
# Create pointers for the first blocks of A and B.
# We will advance this pointer as we move in the K direction
# and accumulate
# `a_ptrs` is a block of [BLOCK_SIZE_M, BLOCK_SIZE_K] pointers
# `b_ptrs` is a block of [BLOCK_SIZE_K, BLOCK_SIZE_N] pointers
num_tokens_post_padded = tl.load(num_tokens_post_padded_ptr)
if pid_m * BLOCK_SIZE_M >= num_tokens_post_padded:
return
offs_token_id = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M).to(tl.int64)
# Cast to int64 to prevent overflow in stride*offset products
offs_token = tl.load(sorted_token_ids_ptr + offs_token_id).to(tl.int64)
token_mask = offs_token < num_valid_tokens
off_experts = tl.load(expert_ids_ptr + pid_m).to(tl.int64)
if off_experts == -1:
# -----------------------------------------------------------
# Write back zeros to the output when the expert is not
# in the current expert parallel rank.
write_zeros_to_output(
c_ptr,
stride_cm,
stride_cn,
pid_n,
N,
offs_token,
token_mask,
BLOCK_SIZE_M,
BLOCK_SIZE_N,
compute_type,
)
return
offs_bn = (pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N).to(tl.int64)) % N
offs_k = tl.arange(0, BLOCK_SIZE_K)
a_ptrs = a_ptr + (
offs_token[:, None] // top_k * stride_am + offs_k[None, :] * stride_ak
)
if use_int4_w4a16:
b_ptrs = (
b_ptr
+ off_experts * stride_be
+ (offs_k[:, None] // 2) * stride_bk
+ offs_bn[None, :] * stride_bn
)
b_shifter = (offs_k[:, None] % 2) * 4
elif use_int8_w8a16:
b_ptrs = (
b_ptr
+ off_experts * stride_be
+ offs_k[:, None] * stride_bk
+ offs_bn[None, :] * stride_bn
)
if not has_zp and use_int4_w4a16:
b_zp_num = 8
if not has_zp and use_int8_w8a16:
b_zp_num = 128
elif has_zp and use_int4_w4a16:
b_zp_shifter = (offs_bn[None, :] % 2) * 4
# -----------------------------------------------------------
# Iterate to compute a block of the C matrix.
# We accumulate into a `[BLOCK_SIZE_M, BLOCK_SIZE_N]` block
# of fp32 values for higher accuracy.
# `accumulator` will be converted back to fp16 after the loop.
accumulator = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
for k in range(0, tl.cdiv(K, BLOCK_SIZE_K)):
# Load the next block of A and B, generate a mask by checking the
# K dimension.
if not block_k_diviable:
k_mask = offs_k[:, None] < K - k * BLOCK_SIZE_K
k_other = 0.0
else:
k_mask = None
k_other = None
a = tl.load(
a_ptrs,
mask=token_mask[:, None] & (offs_k[None, :] < K - k * BLOCK_SIZE_K),
other=0.0,
)
b = tl.load(b_ptrs)
if use_int4_w4a16:
b = (b >> b_shifter) & 0xF
b_scale_ptrs = (
b_scale_ptr
+ off_experts * stride_bse
+ offs_bn[None, :] * stride_bsn
+ ((offs_k[:, None] + BLOCK_SIZE_K * k) // group_size) * stride_bsk
)
b_scale = tl.load(b_scale_ptrs, mask=k_mask, other=k_other)
b_scale = b_scale.to(tl.float32)
if has_zp and use_int4_w4a16:
offs_k_true = (offs_k[:, None] + BLOCK_SIZE_K * k) // group_size
b_zp_ptrs = (
b_zp_ptr
+ off_experts * stride_bze
+ (offs_bn[None, :] // 2) * stride_bzn
+ offs_k_true * stride_bzk
)
b_zp = tl.load(b_zp_ptrs, mask=k_mask, other=k_other)
b_zp = (b_zp >> b_zp_shifter) & 0xF
b_zp = b_zp.to(tl.float32)
elif has_zp and use_int8_w8a16:
offs_k_true = (offs_k[:, None] + BLOCK_SIZE_K * k) // group_size
b_zp_ptrs = (
b_zp_ptr
+ off_experts * stride_bze
+ offs_bn[None, :] * stride_bzn
+ offs_k_true * stride_bzk
)
b_zp = tl.load(b_zp_ptrs, mask=k_mask, other=k_other)
b_zp = b_zp.to(tl.float32)
# We accumulate along the K dimension.
if has_zp:
b = ((b.to(tl.float32) - b_zp) * b_scale).to(compute_type)
else:
b = ((b.to(tl.float32) - b_zp_num) * b_scale).to(compute_type)
accumulator = tl.dot(a, b, acc=accumulator)
# Advance the ptrs to the next K block.
a_ptrs += BLOCK_SIZE_K * stride_ak
if use_int4_w4a16:
b_ptrs += (BLOCK_SIZE_K // 2) * stride_bk
else:
b_ptrs += BLOCK_SIZE_K * stride_bk
if MUL_ROUTED_WEIGHT:
moe_weight = tl.load(topk_weights_ptr + offs_token, mask=token_mask, other=0)
accumulator = accumulator * moe_weight[:, None]
accumulator = accumulator.to(compute_type)
# -----------------------------------------------------------
# Write back the block of the output
offs_cn = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
c_ptrs = c_ptr + stride_cm * offs_token[:, None] + stride_cn * offs_cn[None, :]
c_mask = token_mask[:, None] & (offs_cn[None, :] < N)
tl.store(c_ptrs, accumulator, mask=c_mask)
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