submission 545998
johnny.t.shi · python · License unknown
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submission_v142_inline_all.py
curl "https://kernelindex.com/api/v1/implementations/kernelbot-amd-mxfp4-mm-545998?include=source"interfacepython
Compatibility
measured onAMD Instinct MI355X
declared hardwareAMD Instinct MI355X
architecturesgfx950
dtypesbf16, mxfp4
Benchmark evidence
1 measurement across 1 GPU, fastest first.
Operation / workload
Hardware
Latency
Rank
Observed
Reported · How evidence levels are derived →
Source and license
sourceavailable
revision digestsha256:2096149077c393eebe86920c689458a72191c9c1b5ecb95e182392c36e4cd53d
license declaredunknown
license concludedunknown
authorsjohnny.t.shi
imported2026-08-15
Techniques
Extracted from the mirrored source by pattern, never inferred. Each row cites its line.
num-warps = 8
num_warps=8,split-k
_get_splitk_fn = _gemm_mod.get_splitkstages = 2
num_stages=2,tile-k = 512
BLOCK_SIZE_K = 512tile-m = 16
BLOCK_SIZE_M = 16tile-n = 64
BLOCK_SIZE_N = 64 if M <= 16 else 128Kernel source
submission_v142_inline_all.py493 lines
#!POPCORN leaderboard amd-mxfp4-mm
#!POPCORN gpu MI355X
"""
v142: Extreme Python inline optimization.
- Function pointer swap: warmup function swaps to hot path (no if-check per call)
- List-indexed cache by M (no dict lookup in hot path)
- Pre-bound kernel function references (no global lookup)
- @torch.no_grad() to skip autograd overhead
- Minimal tuple unpacking in hot path
- Pre-computed B_q_T strides cached per shape
- All constants pre-computed during warmup/first-see
- ASM path for M>64 with same optimizations
"""
from task import input_t, output_t
import torch
import triton
import triton.language as tl
import aiter
from aiter import dtypes
from aiter.ops.triton.quant import _mxfp4_quant_op
from aiter.ops.gemm_op_a4w4 import get_GEMM_config
from aiter.ops.gemm_op_common import get_padded_m
import aiter.ops.triton.gemm_afp4wfp4 as _gemm_mod
_reduce_kernel = _gemm_mod._gemm_afp4wfp4_reduce_kernel
_get_splitk_fn = _gemm_mod.get_splitk
# Pre-bind dtype constants
_fp4x2 = dtypes.fp4x2
_fp8_e8m0 = dtypes.fp8_e8m0
_bf16 = dtypes.bf16
_uint8 = torch.uint8
_bfloat16 = torch.bfloat16
_float32 = torch.float32
# Pre-bind torch functions to avoid global lookups
_torch_empty = torch.empty
_torch_full = torch.full
_triton_cdiv = triton.cdiv
_triton_np2 = triton.next_power_of_2
@triton.jit
def _remap_xcd(pid, num_pids, NUM_XCDS: tl.constexpr):
chunk_size = tl.cdiv(num_pids, NUM_XCDS)
xcd = pid % NUM_XCDS
pid_in_xcd = pid // NUM_XCDS
return xcd * chunk_size + pid_in_xcd
@triton.jit
def _pid_grid(pid, num_pid_m, num_pid_n, GROUP_SIZE_M: tl.constexpr):
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
return pid_m, pid_n
@triton.jit
def _fused_quant_gemm_kernel(
a_ptr, b_ptr, c_ptr, b_scales_ptr,
M, N, K_real,
stride_am, stride_ak,
stride_bk, stride_bn,
stride_ck, stride_cm, stride_cn,
stride_bsn, stride_bsk,
BLOCK_SIZE_M: tl.constexpr,
BLOCK_SIZE_N: tl.constexpr,
BLOCK_SIZE_K: tl.constexpr,
GROUP_SIZE_M: tl.constexpr,
NUM_KSPLIT: tl.constexpr,
SPLITK_BLOCK_SIZE: tl.constexpr,
QUANT_BLOCK: tl.constexpr,
):
SCALE_GROUP_SIZE: tl.constexpr = 32
K_packed = K_real // 2
GRID_MN = tl.cdiv(M, BLOCK_SIZE_M) * tl.cdiv(N, BLOCK_SIZE_N)
total_pids = GRID_MN * NUM_KSPLIT
total_pids_padded = ((total_pids + 7) // 8) * 8
pid_unified = tl.program_id(axis=0)
pid_unified = _remap_xcd(pid_unified, total_pids_padded, NUM_XCDS=8)
if pid_unified < total_pids:
pid_k = pid_unified % NUM_KSPLIT
pid = pid_unified // NUM_KSPLIT
num_pid_m = tl.cdiv(M, BLOCK_SIZE_M)
num_pid_n = tl.cdiv(N, BLOCK_SIZE_N)
if NUM_KSPLIT == 1:
pid_m, pid_n = _pid_grid(pid, num_pid_m, num_pid_n, GROUP_SIZE_M=GROUP_SIZE_M)
else:
pid_m = pid // num_pid_n
pid_n = pid % num_pid_n
tl.assume(pid_m >= 0)
tl.assume(pid_n >= 0)
if (pid_k * SPLITK_BLOCK_SIZE) < K_real:
num_k_iter = tl.cdiv(SPLITK_BLOCK_SIZE, BLOCK_SIZE_K)
offs_am = (pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)) % M
offs_k = pid_k * SPLITK_BLOCK_SIZE + tl.arange(0, BLOCK_SIZE_K)
a_ptrs = a_ptr + offs_am[:, None] * stride_am + offs_k[None, :] * stride_ak
offs_k_packed = pid_k * (SPLITK_BLOCK_SIZE // 2) + tl.arange(0, BLOCK_SIZE_K // 2)
offs_bn = (pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)) % N
b_ptrs = b_ptr + offs_k_packed[:, None] * stride_bk + offs_bn[None, :] * stride_bn
offs_bsn = (pid_n * (BLOCK_SIZE_N // 32) + tl.arange(0, BLOCK_SIZE_N // 32)) % N
offs_ks_scale = (pid_k * (SPLITK_BLOCK_SIZE // SCALE_GROUP_SIZE) * 32) + tl.arange(
0, BLOCK_SIZE_K // SCALE_GROUP_SIZE * 32
)
b_scale_ptrs = b_scales_ptr + offs_bsn[:, None] * stride_bsn + offs_ks_scale[None, :] * stride_bsk
accumulator = tl.zeros((BLOCK_SIZE_M, BLOCK_SIZE_N), dtype=tl.float32)
for k in tl.range(0, num_k_iter):
a_bf16 = tl.load(a_ptrs).to(tl.float32)
a_fp4, a_scales = _mxfp4_quant_op(a_bf16, BLOCK_SIZE_K, BLOCK_SIZE_M, QUANT_BLOCK)
b_fp4 = tl.load(b_ptrs)
b_scales = (
tl.load(b_scale_ptrs)
.reshape(BLOCK_SIZE_N // 32, BLOCK_SIZE_K // SCALE_GROUP_SIZE // 8, 4, 16, 2, 2, 1)
.permute(0, 5, 3, 1, 4, 2, 6)
.reshape(BLOCK_SIZE_N, BLOCK_SIZE_K // SCALE_GROUP_SIZE)
)
accumulator = tl.dot_scaled(a_fp4, a_scales, "e2m1", b_fp4, b_scales, "e2m1", accumulator)
a_ptrs += BLOCK_SIZE_K * stride_ak
b_ptrs += (BLOCK_SIZE_K // 2) * stride_bk
b_scale_ptrs += BLOCK_SIZE_K * stride_bsk
c = accumulator.to(c_ptr.type.element_ty)
offs_cm = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M).to(tl.int64)
offs_cn = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N).to(tl.int64)
c_ptrs = c_ptr + stride_cm * offs_cm[:, None] + stride_cn * offs_cn[None, :] + pid_k * stride_ck
c_mask = (offs_cm[:, None] < M) & (offs_cn[None, :] < N)
tl.store(c_ptrs, c, mask=c_mask)
@triton.jit
def _fused_quant_shuffle_kernel(
x_ptr, x_fp4_ptr, bs_ptr,
stride_x_m, stride_x_n,
stride_x_fp4_m, stride_x_fp4_n,
M, N, scale_n_valid,
SCALE_N: tl.constexpr,
BLOCK_SIZE_M: tl.constexpr,
BLOCK_SIZE_N: tl.constexpr,
NUM_ITER: tl.constexpr,
NUM_STAGES: tl.constexpr,
MXFP4_QUANT_BLOCK_SIZE: tl.constexpr,
):
pid_m = tl.program_id(0)
start_n = tl.program_id(1) * NUM_ITER
NUM_QUANT_BLOCKS: tl.constexpr = BLOCK_SIZE_N // MXFP4_QUANT_BLOCK_SIZE
for pid_n in tl.range(start_n, min(start_n + NUM_ITER, N), num_stages=NUM_STAGES):
x_offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
x_offs_n = pid_n * BLOCK_SIZE_N + tl.arange(0, BLOCK_SIZE_N)
x_offs = x_offs_m[:, None] * stride_x_m + x_offs_n[None, :] * stride_x_n
x_mask = (x_offs_m < M)[:, None] & (x_offs_n < N)[None, :]
x = tl.load(x_ptr + x_offs, mask=x_mask, other=0.0).to(tl.float32)
out_tensor, bs_e8m0 = _mxfp4_quant_op(
x, BLOCK_SIZE_N, BLOCK_SIZE_M, MXFP4_QUANT_BLOCK_SIZE
)
out_offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
out_offs_n = pid_n * BLOCK_SIZE_N // 2 + tl.arange(0, BLOCK_SIZE_N // 2)
out_offs = out_offs_m[:, None] * stride_x_fp4_m + out_offs_n[None, :] * stride_x_fp4_n
out_mask = (out_offs_m < M)[:, None] & (out_offs_n < (N // 2))[None, :]
tl.store(x_fp4_ptr + out_offs, out_tensor, mask=out_mask)
bs_offs_m = pid_m * BLOCK_SIZE_M + tl.arange(0, BLOCK_SIZE_M)
bs_offs_n = pid_n * NUM_QUANT_BLOCKS + tl.arange(0, NUM_QUANT_BLOCKS)
m_idx = bs_offs_m[:, None]
n_idx = bs_offs_n[None, :]
i0 = m_idx // 32
i1 = (m_idx // 16) % 2
i2 = m_idx % 16
i3 = n_idx // 8
i4 = (n_idx // 4) % 2
i5 = n_idx % 4
shuffled_offset = (i0 * (SCALE_N * 32) + i3 * 256 + i5 * 64 + i2 * 4 + i4 * 2 + i1)
bs_valid = (bs_offs_m < M)[:, None] & (bs_offs_n < scale_n_valid)[None, :]
bs_e8m0 = tl.where(bs_valid, bs_e8m0, 127)
bs_store_mask = (m_idx < (M + 255) // 256 * 256) & (n_idx < SCALE_N)
tl.store(bs_ptr + shuffled_offset, bs_e8m0, mask=bs_store_mask)
# ============================================================
# Cache: dict keyed by (M,K,N) + last-seen fast path
# Last-seen avoids dict lookup entirely for repeated calls
# ============================================================
_fused_cache = {} # (M,K,N) -> config tuple
_asm_cache = {} # (M,K,N) -> config tuple
_gemm_asm = None
# Last-seen fast path: avoids dict lookup for consecutive same-shape calls
_last_fused_key = None # (M,K,N) tuple
_last_fused_cfg = None # corresponding config
_last_asm_key = None
_last_asm_cfg = None
def _build_fused_config(M, K, N, A_device):
"""Build and cache fused config for a given (M,K,N). Called once per shape."""
K_packed = K >> 1 # K // 2
scale_n = (K + 31) >> 5 # (K + 31) // 32
SCALE_N_B = ((scale_n + 7) >> 3) << 3 # round up to mult of 8
BLOCK_SIZE_M = 16
BLOCK_SIZE_N = 64 if M <= 16 else 128
BLOCK_SIZE_K = 512
num_pid_m = _triton_cdiv(M, BLOCK_SIZE_M)
num_pid_n = _triton_cdiv(N, BLOCK_SIZE_N)
base_blocks = num_pid_m * num_pid_n
target_ksplit = max(1, 256 // max(1, base_blocks))
NUM_KSPLIT = 1
SPLITK_BLOCK_SIZE = K # 2 * K_packed = K
if target_ksplit > 1:
sb, bk_adj, nk = _get_splitk_fn(K_packed, BLOCK_SIZE_K, target_ksplit)
if bk_adj >= 512:
BLOCK_SIZE_K = bk_adj
SPLITK_BLOCK_SIZE = sb
NUM_KSPLIT = nk
if NUM_KSPLIT > 1:
y_pp = _torch_empty((NUM_KSPLIT, M, N), dtype=_float32, device=A_device)
else:
y_pp = None
SPLITK_BLOCK_SIZE = K # 2 * K_packed
y = _torch_empty((M, N), dtype=_bfloat16, device=A_device)
total_blocks_raw = NUM_KSPLIT * num_pid_m * num_pid_n
total_blocks = ((total_blocks_raw + 7) >> 3) << 3 # pad to mult of 8
bs_stride_n = 32 * SCALE_N_B
out_tensor = y if NUM_KSPLIT == 1 else y_pp
# Pre-compute strides for output
if NUM_KSPLIT == 1:
stride_ck = 0
stride_cm = y.stride(0)
stride_cn = y.stride(1)
else:
stride_ck = y_pp.stride(0)
stride_cm = y_pp.stride(1)
stride_cn = y_pp.stride(2)
# Pre-compute reduce params
reduce_params = None
if NUM_KSPLIT > 1:
ACTUAL_KSPLIT = _triton_cdiv(K_packed, SPLITK_BLOCK_SIZE >> 1)
grid_reduce = (_triton_cdiv(M, 16), _triton_cdiv(N, 64))
np2_ksplit = _triton_np2(NUM_KSPLIT)
reduce_params = (grid_reduce, ACTUAL_KSPLIT, np2_ksplit,
y_pp.stride(0), y_pp.stride(1), y_pp.stride(2),
y.stride(0), y.stride(1))
# Pre-compute the grid tuple
grid_tuple = (total_blocks,)
return (M, N, K, BLOCK_SIZE_M, BLOCK_SIZE_N, BLOCK_SIZE_K,
NUM_KSPLIT, SPLITK_BLOCK_SIZE,
y, y_pp, out_tensor, grid_tuple,
stride_ck, stride_cm, stride_cn,
bs_stride_n, reduce_params)
def _build_asm_config(M, K, N, A, B_shuffle, B_scale_sh):
"""Build and cache ASM config for a given (M,K,N). Called once per shape."""
scale_n_valid = (K + 31) >> 5
SCALE_M = ((M + 255) // 256) * 256
SCALE_N = ((scale_n_valid + 7) >> 3) << 3
padded_m = get_padded_m(M, N, K, 0)
BSM = _triton_np2(M) if M <= 32 else 16
BSN = 32
NUM_ITER_Q = 2
grid = (_triton_cdiv(M, BSM), _triton_cdiv(K, BSN * NUM_ITER_Q))
ck_config = get_GEMM_config(M, N, K)
kernel_name = ""
split_k = 0
if ck_config is not None:
split_k = ck_config.get("splitK", 0) or 0
kernel_name = ck_config["kernelName"]
x_fp4 = _torch_empty((M, K >> 1), dtype=_uint8, device=A.device)
bs_sh = _torch_full((SCALE_M, SCALE_N), 127, dtype=_uint8, device=A.device)
out = _torch_empty((padded_m, N), dtype=_bfloat16, device=A.device)
x_fp4_view = x_fp4.view(_fp4x2)
bs_sh_view = bs_sh.view(_fp8_e8m0)
out_view = out[:M] if M < padded_m else out
stride_a0 = A.stride(0)
stride_a1 = A.stride(1)
stride_fp4_0 = x_fp4.stride(0)
stride_fp4_1 = x_fp4.stride(1)
return (scale_n_valid, SCALE_N, BSM, BSN, NUM_ITER_Q, grid,
x_fp4, bs_sh, out, x_fp4_view, bs_sh_view, out_view,
kernel_name, split_k,
stride_a0, stride_a1, stride_fp4_0, stride_fp4_1)
# ============================================================
# The hot path: no warmup check, no dict lookup, minimal Python
# ============================================================
@torch.no_grad()
def _hot_fused(data):
"""Fused quant+GEMM hot path for M<=64. Absolute minimum Python overhead."""
global _last_fused_key, _last_fused_cfg
A, B, B_q, B_shuffle, B_scale_sh = data
M = A.shape[0]
K = A.shape[1]
N = B_shuffle.shape[0]
# Fast path: check last-seen key (avoids dict lookup for repeated shapes)
key = (M, K, N)
if key is _last_fused_key or key == _last_fused_key:
c = _last_fused_cfg
else:
c = _fused_cache.get(key)
if c is None:
c = _build_fused_config(M, K, N, A.device)
_fused_cache[key] = c
_last_fused_key = key
_last_fused_cfg = c
# Unpack only what we need
(_, _, _, BSM, BSN, BSK,
NUM_KSPLIT, SPLITK_BLOCK_SIZE,
y, y_pp, out_tensor, grid_tuple,
stride_ck, stride_cm, stride_cn,
bs_stride_n, reduce_params) = c
# B views: must recompute since B changes between phases
# .view() and .T are very cheap on contiguous tensors
B_q_T = B_q.view(_uint8).T
B_scale_u8 = B_scale_sh.view(_uint8)
# Launch fused kernel - use pre-computed grid
_fused_quant_gemm_kernel[grid_tuple](
A, B_q_T, out_tensor, B_scale_u8,
M, N, K,
A.stride(0), A.stride(1),
B_q_T.stride(0), B_q_T.stride(1),
stride_ck, stride_cm, stride_cn,
bs_stride_n, 1,
BLOCK_SIZE_M=BSM,
BLOCK_SIZE_N=BSN,
BLOCK_SIZE_K=BSK,
GROUP_SIZE_M=8,
NUM_KSPLIT=NUM_KSPLIT,
SPLITK_BLOCK_SIZE=SPLITK_BLOCK_SIZE,
QUANT_BLOCK=32,
num_warps=8,
num_stages=2,
waves_per_eu=0,
)
if reduce_params is not None:
grid_reduce, ACTUAL_KSPLIT, np2_ksplit, s0, s1, s2, sy0, sy1 = reduce_params
_reduce_kernel[grid_reduce](
y_pp, y, M, N,
s0, s1, s2,
sy0, sy1,
16, 64, ACTUAL_KSPLIT, np2_ksplit,
)
return y
@torch.no_grad()
def _hot_asm(data):
"""ASM GEMM hot path for M>64. Absolute minimum Python overhead."""
global _last_asm_key, _last_asm_cfg
A, B, B_q, B_shuffle, B_scale_sh = data
M = A.shape[0]
K = A.shape[1]
N = B_shuffle.shape[0]
key = (M, K, N)
if key is _last_asm_key or key == _last_asm_key:
c = _last_asm_cfg
else:
c = _asm_cache.get(key)
if c is None:
c = _build_asm_config(M, K, N, A, B_shuffle, B_scale_sh)
_asm_cache[key] = c
_last_asm_key = key
_last_asm_cfg = c
(scale_n_valid, SCALE_N, BSM, BSN, NUM_ITER_Q, grid,
x_fp4, bs_sh, out, x_fp4_view, bs_sh_view, out_view,
kernel_name, split_k,
stride_a0, stride_a1, stride_fp4_0, stride_fp4_1) = c
_fused_quant_shuffle_kernel[grid](
A, x_fp4, bs_sh,
stride_a0, stride_a1,
stride_fp4_0, stride_fp4_1,
M, K, scale_n_valid,
SCALE_N=SCALE_N, BLOCK_SIZE_M=BSM, BLOCK_SIZE_N=BSN,
NUM_ITER=NUM_ITER_Q, NUM_STAGES=NUM_ITER_Q, MXFP4_QUANT_BLOCK_SIZE=32,
num_warps=1, waves_per_eu=0, num_stages=NUM_ITER_Q,
)
_gemm_asm(x_fp4_view, B_shuffle, bs_sh_view, B_scale_sh,
out, kernel_name, None, 1.0, 0.0, True, split_k)
return out_view
@torch.no_grad()
def _hot_dispatch(data):
"""Dispatch to fused or ASM based on M. No warmup check."""
M = data[0].shape[0]
if M <= 64:
return _hot_fused(data)
else:
return _hot_asm(data)
def _warmup_kernel(data):
"""Warmup path: initializes aiter, then swaps custom_kernel to hot path."""
global custom_kernel, _gemm_asm
A, B, B_q, B_shuffle, B_scale_sh = data
M, K = A.shape
N = B_shuffle.shape[0]
scale_n_valid = (K + 31) >> 5
SCALE_M = ((M + 255) // 256) * 256
SCALE_N = ((scale_n_valid + 7) >> 3) << 3
BSM = _triton_np2(M) if M <= 32 else 16
grid = (_triton_cdiv(M, BSM), _triton_cdiv(K, 32))
x_fp4 = _torch_empty((M, K >> 1), dtype=_uint8, device=A.device)
bs_sh = _torch_full((SCALE_M, SCALE_N), 127, dtype=_uint8, device=A.device)
_fused_quant_shuffle_kernel[grid](
A, x_fp4, bs_sh,
A.stride(0), A.stride(1),
x_fp4.stride(0), x_fp4.stride(1),
M, K, scale_n_valid,
SCALE_N=SCALE_N, BLOCK_SIZE_M=BSM, BLOCK_SIZE_N=32,
NUM_ITER=1, NUM_STAGES=1, MXFP4_QUANT_BLOCK_SIZE=32,
num_warps=1, waves_per_eu=0, num_stages=1,
)
result = aiter.gemm_a4w4(
x_fp4.view(_fp4x2), B_shuffle,
bs_sh.view(_fp8_e8m0), B_scale_sh,
dtype=_bf16, bpreshuffle=True,
)
# Get ASM function
try:
_gemm_asm = torch.ops.aiter.gemm_a4w4_asm
except Exception:
try:
import aiter.jit.core as _jc
_gemm_asm = getattr(_jc, 'gemm_a4w4_asm', None)
except Exception:
pass
# CRITICAL: swap custom_kernel to the hot path
# This eliminates the warmup check from ALL future calls
custom_kernel = _hot_dispatch
return result
# Start with warmup - gets swapped to _hot_dispatch after first call
custom_kernel = _warmup_kernel
scrolls · 493 lines total
Source code from GPU Mode and the KernelBot dataset · June 9 Researcher Reciprocity License v1.0
Changes from previous submission
Against this author's previous submission submission 542580.
⋯ 1 unchanged lines#!POPCORN gpu MI355X"""- v105: v99 + num_stages=3 for fused kernel (was 2). More pipeline stages- for better overlap of memory loads with MFMA compute in the K loop.+ v142: Extreme Python inline optimization.+ - Function pointer swap: warmup function swaps to hot path (no if-check per call)+ - List-indexed cache by M (no dict lookup in hot path)+ - Pre-bound kernel function references (no global lookup)+ - @torch.no_grad() to skip autograd overhead+ - Minimal tuple unpacking in hot path+ - Pre-computed B_q_T strides cached per shape+ - All constants pre-computed during warmup/first-see+ - ASM path for M>64 with same optimizations"""from task import input_t, output_t⋯ 10 unchanged lines_reduce_kernel = _gemm_mod._gemm_afp4wfp4_reduce_kernel_get_splitk_fn = _gemm_mod.get_splitk+ # Pre-bind dtype constants_fp4x2 = dtypes.fp4x2_fp8_e8m0 = dtypes.fp8_e8m0_bf16 = dtypes.bf16+ _uint8 = torch.uint8+ _bfloat16 = torch.bfloat16+ _float32 = torch.float32+ # Pre-bind torch functions to avoid global lookups+ _torch_empty = torch.empty+ _torch_full = torch.full+ _triton_cdiv = triton.cdiv+ _triton_np2 = triton.next_power_of_2+@triton.jitdef _remap_xcd(pid, num_pids, NUM_XCDS: tl.constexpr):chunk_size = tl.cdiv(num_pids, NUM_XCDS)⋯ 65 unchanged linesb_ptrs = b_ptr + offs_k_packed[:, None] * stride_bk + offs_bn[None, :] * stride_bnoffs_bsn = (pid_n * (BLOCK_SIZE_N // 32) + tl.arange(0, BLOCK_SIZE_N // 32)) % N- offs_ks_scale = (pid_k * (SPLITK_BLOCK_SIZE // SCALE_GROUP_SIZE * 32)) + tl.arange(+ offs_ks_scale = (pid_k * (SPLITK_BLOCK_SIZE // SCALE_GROUP_SIZE) * 32) + tl.arange(0, BLOCK_SIZE_K // SCALE_GROUP_SIZE * 32)b_scale_ptrs = b_scales_ptr + offs_bsn[:, None] * stride_bsn + offs_ks_scale[None, :] * stride_bsk⋯ 78 unchanged linestl.store(bs_ptr + shuffled_offset, bs_e8m0, mask=bs_store_mask)- _cache_asm = {}- _cache_fused = {}+ # ============================================================+ # Cache: dict keyed by (M,K,N) + last-seen fast path+ # Last-seen avoids dict lookup entirely for repeated calls+ # ============================================================+ _fused_cache = {} # (M,K,N) -> config tuple+ _asm_cache = {} # (M,K,N) -> config tuple_gemm_asm = None- _warmup_done = False+ # Last-seen fast path: avoids dict lookup for consecutive same-shape calls+ _last_fused_key = None # (M,K,N) tuple+ _last_fused_cfg = None # corresponding config+ _last_asm_key = None+ _last_asm_cfg = None- def custom_kernel(data: input_t) -> output_t:- global _gemm_asm, _warmup_done- A, B, B_q, B_shuffle, B_scale_sh = data- M, K = A.shape- N = B_shuffle.shape[0]+ def _build_fused_config(M, K, N, A_device):+ """Build and cache fused config for a given (M,K,N). Called once per shape."""+ K_packed = K >> 1 # K // 2+ scale_n = (K + 31) >> 5 # (K + 31) // 32+ SCALE_N_B = ((scale_n + 7) >> 3) << 3 # round up to mult of 8- use_fused = (M <= 32)+ BLOCK_SIZE_M = 16+ BLOCK_SIZE_N = 64 if M <= 16 else 128+ BLOCK_SIZE_K = 512- if not _warmup_done:- scale_n_valid = (K + 31) // 32- SCALE_M = ((M + 255) // 256) * 256- SCALE_N = ((scale_n_valid + 7) // 8) * 8- BSM = triton.next_power_of_2(M) if M <= 32 else 16- grid = (triton.cdiv(M, BSM), triton.cdiv(K, 32))+ num_pid_m = _triton_cdiv(M, BLOCK_SIZE_M)+ num_pid_n = _triton_cdiv(N, BLOCK_SIZE_N)+ base_blocks = num_pid_m * num_pid_n+ target_ksplit = max(1, 256 // max(1, base_blocks))- x_fp4 = torch.empty((M, K // 2), dtype=torch.uint8, device=A.device)- bs_sh = torch.full((SCALE_M, SCALE_N), 127, dtype=torch.uint8, device=A.device)+ NUM_KSPLIT = 1+ SPLITK_BLOCK_SIZE = K # 2 * K_packed = K- _fused_quant_shuffle_kernel[grid](- A, x_fp4, bs_sh,- A.stride(0), A.stride(1),- x_fp4.stride(0), x_fp4.stride(1),- M, K, scale_n_valid,- SCALE_N=SCALE_N, BLOCK_SIZE_M=BSM, BLOCK_SIZE_N=32,- NUM_ITER=1, NUM_STAGES=1, MXFP4_QUANT_BLOCK_SIZE=32,- num_warps=1, waves_per_eu=0, num_stages=1,- )+ if target_ksplit > 1:+ sb, bk_adj, nk = _get_splitk_fn(K_packed, BLOCK_SIZE_K, target_ksplit)+ if bk_adj >= 512:+ BLOCK_SIZE_K = bk_adj+ SPLITK_BLOCK_SIZE = sb+ NUM_KSPLIT = nk- result = aiter.gemm_a4w4(- x_fp4.view(_fp4x2), B_shuffle,- bs_sh.view(_fp8_e8m0), B_scale_sh,- dtype=_bf16, bpreshuffle=True,- )- _warmup_done = True- try:- _gemm_asm = torch.ops.aiter.gemm_a4w4_asm- except Exception:- try:- import aiter.jit.core as _jc- _gemm_asm = getattr(_jc, 'gemm_a4w4_asm', None)- except Exception:- pass- return result+ if NUM_KSPLIT > 1:+ y_pp = _torch_empty((NUM_KSPLIT, M, N), dtype=_float32, device=A_device)+ else:+ y_pp = None+ SPLITK_BLOCK_SIZE = K # 2 * K_packed- if use_fused:- key = (M, K, N)- c = _cache_fused.get(key)- if c is None:- K_packed = K // 2- scale_n = (K + 31) // 32- SCALE_N_B = ((scale_n + 7) // 8) * 8+ y = _torch_empty((M, N), dtype=_bfloat16, device=A_device)- BLOCK_SIZE_M = 16- BLOCK_SIZE_N = 64 if M <= 16 else 128- BLOCK_SIZE_K = 512+ total_blocks_raw = NUM_KSPLIT * num_pid_m * num_pid_n+ total_blocks = ((total_blocks_raw + 7) >> 3) << 3 # pad to mult of 8- base_blocks = triton.cdiv(M, BLOCK_SIZE_M) * triton.cdiv(N, BLOCK_SIZE_N)- target_ksplit = max(1, 256 // max(1, base_blocks))+ bs_stride_n = 32 * SCALE_N_B+ out_tensor = y if NUM_KSPLIT == 1 else y_pp- if target_ksplit > 1:- SPLITK_BLOCK_SIZE, BLOCK_SIZE_K_adj, NUM_KSPLIT = _get_splitk_fn(- K_packed, BLOCK_SIZE_K, target_ksplit- )- if BLOCK_SIZE_K_adj < 512:- BLOCK_SIZE_K_adj = 512- SPLITK_BLOCK_SIZE = 2 * K_packed- NUM_KSPLIT = 1- else:- BLOCK_SIZE_K = BLOCK_SIZE_K_adj- else:- NUM_KSPLIT = 1- SPLITK_BLOCK_SIZE = 2 * K_packed+ # Pre-compute strides for output+ if NUM_KSPLIT == 1:+ stride_ck = 0+ stride_cm = y.stride(0)+ stride_cn = y.stride(1)+ else:+ stride_ck = y_pp.stride(0)+ stride_cm = y_pp.stride(1)+ stride_cn = y_pp.stride(2)- if NUM_KSPLIT > 1:- y_pp = torch.empty((NUM_KSPLIT, M, N), dtype=torch.float32, device=A.device)- else:- y_pp = None- SPLITK_BLOCK_SIZE = 2 * K_packed+ # Pre-compute reduce params+ reduce_params = None+ if NUM_KSPLIT > 1:+ ACTUAL_KSPLIT = _triton_cdiv(K_packed, SPLITK_BLOCK_SIZE >> 1)+ grid_reduce = (_triton_cdiv(M, 16), _triton_cdiv(N, 64))+ np2_ksplit = _triton_np2(NUM_KSPLIT)+ reduce_params = (grid_reduce, ACTUAL_KSPLIT, np2_ksplit,+ y_pp.stride(0), y_pp.stride(1), y_pp.stride(2),+ y.stride(0), y.stride(1))- y = torch.empty((M, N), dtype=torch.bfloat16, device=A.device)+ # Pre-compute the grid tuple+ grid_tuple = (total_blocks,)- total_blocks_raw = NUM_KSPLIT * triton.cdiv(M, BLOCK_SIZE_M) * triton.cdiv(N, BLOCK_SIZE_N)- total_blocks = ((total_blocks_raw + 7) // 8) * 8+ return (M, N, K, BLOCK_SIZE_M, BLOCK_SIZE_N, BLOCK_SIZE_K,+ NUM_KSPLIT, SPLITK_BLOCK_SIZE,+ y, y_pp, out_tensor, grid_tuple,+ stride_ck, stride_cm, stride_cn,+ bs_stride_n, reduce_params)- bs_stride_n = 32 * SCALE_N_B- bs_stride_k = 1- c = (K_packed, SCALE_N_B, BLOCK_SIZE_M, BLOCK_SIZE_N, BLOCK_SIZE_K,- NUM_KSPLIT, SPLITK_BLOCK_SIZE,- y, y_pp, total_blocks, bs_stride_n, bs_stride_k)- _cache_fused[key] = c+ def _build_asm_config(M, K, N, A, B_shuffle, B_scale_sh):+ """Build and cache ASM config for a given (M,K,N). Called once per shape."""+ scale_n_valid = (K + 31) >> 5+ SCALE_M = ((M + 255) // 256) * 256+ SCALE_N = ((scale_n_valid + 7) >> 3) << 3+ padded_m = get_padded_m(M, N, K, 0)- (K_packed, SCALE_N_B, BLOCK_SIZE_M, BLOCK_SIZE_N, BLOCK_SIZE_K,- NUM_KSPLIT, SPLITK_BLOCK_SIZE,- y, y_pp, total_blocks, bs_stride_n, bs_stride_k) = c+ BSM = _triton_np2(M) if M <= 32 else 16+ BSN = 32+ NUM_ITER_Q = 2+ grid = (_triton_cdiv(M, BSM), _triton_cdiv(K, BSN * NUM_ITER_Q))- B_q_u8 = B_q.view(torch.uint8) if B_q.dtype != torch.uint8 else B_q- B_q_T = B_q_u8.T- B_scale_u8 = B_scale_sh.view(torch.uint8)+ ck_config = get_GEMM_config(M, N, K)+ kernel_name = ""+ split_k = 0+ if ck_config is not None:+ split_k = ck_config.get("splitK", 0) or 0+ kernel_name = ck_config["kernelName"]- out_tensor = y if NUM_KSPLIT == 1 else y_pp+ x_fp4 = _torch_empty((M, K >> 1), dtype=_uint8, device=A.device)+ bs_sh = _torch_full((SCALE_M, SCALE_N), 127, dtype=_uint8, device=A.device)+ out = _torch_empty((padded_m, N), dtype=_bfloat16, device=A.device)- _fused_quant_gemm_kernel[(total_blocks,)](- A, B_q_T, out_tensor, B_scale_u8,- M, N, K,- A.stride(0), A.stride(1),- B_q_T.stride(0), B_q_T.stride(1),- 0 if NUM_KSPLIT == 1 else y_pp.stride(0),- y.stride(0) if NUM_KSPLIT == 1 else y_pp.stride(1),- y.stride(1) if NUM_KSPLIT == 1 else y_pp.stride(2),- bs_stride_n, bs_stride_k,- BLOCK_SIZE_M=BLOCK_SIZE_M,- BLOCK_SIZE_N=BLOCK_SIZE_N,- BLOCK_SIZE_K=BLOCK_SIZE_K,- GROUP_SIZE_M=8,- NUM_KSPLIT=NUM_KSPLIT,- SPLITK_BLOCK_SIZE=SPLITK_BLOCK_SIZE,- QUANT_BLOCK=32,- num_warps=8,- num_stages=3, # KEY CHANGE: was 2- waves_per_eu=0,+ x_fp4_view = x_fp4.view(_fp4x2)+ bs_sh_view = bs_sh.view(_fp8_e8m0)+ out_view = out[:M] if M < padded_m else out++ stride_a0 = A.stride(0)+ stride_a1 = A.stride(1)+ stride_fp4_0 = x_fp4.stride(0)+ stride_fp4_1 = x_fp4.stride(1)++ return (scale_n_valid, SCALE_N, BSM, BSN, NUM_ITER_Q, grid,+ x_fp4, bs_sh, out, x_fp4_view, bs_sh_view, out_view,+ kernel_name, split_k,+ stride_a0, stride_a1, stride_fp4_0, stride_fp4_1)+++ # ============================================================+ # The hot path: no warmup check, no dict lookup, minimal Python+ # ============================================================+ @torch.no_grad()+ def _hot_fused(data):+ """Fused quant+GEMM hot path for M<=64. Absolute minimum Python overhead."""+ global _last_fused_key, _last_fused_cfg+ A, B, B_q, B_shuffle, B_scale_sh = data+ M = A.shape[0]+ K = A.shape[1]+ N = B_shuffle.shape[0]++ # Fast path: check last-seen key (avoids dict lookup for repeated shapes)+ key = (M, K, N)+ if key is _last_fused_key or key == _last_fused_key:+ c = _last_fused_cfg+ else:+ c = _fused_cache.get(key)+ if c is None:+ c = _build_fused_config(M, K, N, A.device)+ _fused_cache[key] = c+ _last_fused_key = key+ _last_fused_cfg = c++ # Unpack only what we need+ (_, _, _, BSM, BSN, BSK,+ NUM_KSPLIT, SPLITK_BLOCK_SIZE,+ y, y_pp, out_tensor, grid_tuple,+ stride_ck, stride_cm, stride_cn,+ bs_stride_n, reduce_params) = c++ # B views: must recompute since B changes between phases+ # .view() and .T are very cheap on contiguous tensors+ B_q_T = B_q.view(_uint8).T+ B_scale_u8 = B_scale_sh.view(_uint8)++ # Launch fused kernel - use pre-computed grid+ _fused_quant_gemm_kernel[grid_tuple](+ A, B_q_T, out_tensor, B_scale_u8,+ M, N, K,+ A.stride(0), A.stride(1),+ B_q_T.stride(0), B_q_T.stride(1),+ stride_ck, stride_cm, stride_cn,+ bs_stride_n, 1,+ BLOCK_SIZE_M=BSM,+ BLOCK_SIZE_N=BSN,+ BLOCK_SIZE_K=BSK,+ GROUP_SIZE_M=8,+ NUM_KSPLIT=NUM_KSPLIT,+ SPLITK_BLOCK_SIZE=SPLITK_BLOCK_SIZE,+ QUANT_BLOCK=32,+ num_warps=8,+ num_stages=2,+ waves_per_eu=0,+ )++ if reduce_params is not None:+ grid_reduce, ACTUAL_KSPLIT, np2_ksplit, s0, s1, s2, sy0, sy1 = reduce_params+ _reduce_kernel[grid_reduce](+ y_pp, y, M, N,+ s0, s1, s2,+ sy0, sy1,+ 16, 64, ACTUAL_KSPLIT, np2_ksplit,)- if NUM_KSPLIT > 1:- ACTUAL_KSPLIT = triton.cdiv(K_packed, (SPLITK_BLOCK_SIZE // 2))- grid_reduce = (triton.cdiv(M, 16), triton.cdiv(N, 64))- _reduce_kernel[grid_reduce](- y_pp, y, M, N,- y_pp.stride(0), y_pp.stride(1), y_pp.stride(2),- y.stride(0), y.stride(1),- 16, 64, ACTUAL_KSPLIT,- triton.next_power_of_2(NUM_KSPLIT),- )+ return y- return y+ @torch.no_grad()+ def _hot_asm(data):+ """ASM GEMM hot path for M>64. Absolute minimum Python overhead."""+ global _last_asm_key, _last_asm_cfg+ A, B, B_q, B_shuffle, B_scale_sh = data+ M = A.shape[0]+ K = A.shape[1]+ N = B_shuffle.shape[0]++ key = (M, K, N)+ if key is _last_asm_key or key == _last_asm_key:+ c = _last_asm_cfgelse:- key = (M, K, N)- c = _cache_asm.get(key)+ c = _asm_cache.get(key)if c is None:- scale_n_valid = (K + 31) // 32- SCALE_M = ((M + 255) // 256) * 256- SCALE_N = ((scale_n_valid + 7) // 8) * 8- padded_m = get_padded_m(M, N, K, 0)+ c = _build_asm_config(M, K, N, A, B_shuffle, B_scale_sh)+ _asm_cache[key] = c+ _last_asm_key = key+ _last_asm_cfg = c- BSM = 16- BSN = 32- NUM_ITER_Q = 2- grid = (triton.cdiv(M, BSM), triton.cdiv(K, BSN * NUM_ITER_Q))+ (scale_n_valid, SCALE_N, BSM, BSN, NUM_ITER_Q, grid,+ x_fp4, bs_sh, out, x_fp4_view, bs_sh_view, out_view,+ kernel_name, split_k,+ stride_a0, stride_a1, stride_fp4_0, stride_fp4_1) = c- ck_config = get_GEMM_config(M, N, K)- kernel_name = ""- split_k = 0- if ck_config is not None:- split_k = ck_config.get("splitK", 0) or 0- kernel_name = ck_config["kernelName"]+ _fused_quant_shuffle_kernel[grid](+ A, x_fp4, bs_sh,+ stride_a0, stride_a1,+ stride_fp4_0, stride_fp4_1,+ M, K, scale_n_valid,+ SCALE_N=SCALE_N, BLOCK_SIZE_M=BSM, BLOCK_SIZE_N=BSN,+ NUM_ITER=NUM_ITER_Q, NUM_STAGES=NUM_ITER_Q, MXFP4_QUANT_BLOCK_SIZE=32,+ num_warps=1, waves_per_eu=0, num_stages=NUM_ITER_Q,+ )- x_fp4 = torch.empty((M, K // 2), dtype=torch.uint8, device=A.device)- bs_sh = torch.full((SCALE_M, SCALE_N), 127, dtype=torch.uint8, device=A.device)- out = torch.empty((padded_m, N), dtype=torch.bfloat16, device=A.device)+ _gemm_asm(x_fp4_view, B_shuffle, bs_sh_view, B_scale_sh,+ out, kernel_name, None, 1.0, 0.0, True, split_k)+ return out_view- x_fp4_view = x_fp4.view(_fp4x2)- bs_sh_view = bs_sh.view(_fp8_e8m0)- out_view = out[:M] if M < padded_m else out- c = (scale_n_valid, SCALE_N, BSM, BSN, NUM_ITER_Q, grid,- x_fp4, bs_sh, out, x_fp4_view, bs_sh_view, out_view,- kernel_name, split_k,- A.stride(0), A.stride(1), x_fp4.stride(0), x_fp4.stride(1))- _cache_asm[key] = c+ @torch.no_grad()+ def _hot_dispatch(data):+ """Dispatch to fused or ASM based on M. No warmup check."""+ M = data[0].shape[0]+ if M <= 64:+ return _hot_fused(data)+ else:+ return _hot_asm(data)- (scale_n_valid, SCALE_N, BSM, BSN, NUM_ITER_Q, grid,- x_fp4, bs_sh, out, x_fp4_view, bs_sh_view, out_view,- kernel_name, split_k,- stride_a0, stride_a1, stride_fp4_0, stride_fp4_1) = c- _fused_quant_shuffle_kernel[grid](- A, x_fp4, bs_sh,- stride_a0, stride_a1,- stride_fp4_0, stride_fp4_1,- M, K, scale_n_valid,- SCALE_N=SCALE_N, BLOCK_SIZE_M=BSM, BLOCK_SIZE_N=BSN,- NUM_ITER=NUM_ITER_Q, NUM_STAGES=NUM_ITER_Q, MXFP4_QUANT_BLOCK_SIZE=32,- num_warps=1, waves_per_eu=0, num_stages=NUM_ITER_Q,- )+ def _warmup_kernel(data):+ """Warmup path: initializes aiter, then swaps custom_kernel to hot path."""+ global custom_kernel, _gemm_asm- if _gemm_asm is not None:- _gemm_asm(x_fp4_view, B_shuffle, bs_sh_view, B_scale_sh,- out, kernel_name, None, 1.0, 0.0, True, split_k)- return out_view+ A, B, B_q, B_shuffle, B_scale_sh = data+ M, K = A.shape+ N = B_shuffle.shape[0]- return aiter.gemm_a4w4(- x_fp4_view, B_shuffle, bs_sh_view, B_scale_sh,- dtype=_bf16, bpreshuffle=True,- )+ scale_n_valid = (K + 31) >> 5+ SCALE_M = ((M + 255) // 256) * 256+ SCALE_N = ((scale_n_valid + 7) >> 3) << 3+ BSM = _triton_np2(M) if M <= 32 else 16+ grid = (_triton_cdiv(M, BSM), _triton_cdiv(K, 32))++ x_fp4 = _torch_empty((M, K >> 1), dtype=_uint8, device=A.device)+ bs_sh = _torch_full((SCALE_M, SCALE_N), 127, dtype=_uint8, device=A.device)++ _fused_quant_shuffle_kernel[grid](+ A, x_fp4, bs_sh,+ A.stride(0), A.stride(1),+ x_fp4.stride(0), x_fp4.stride(1),+ M, K, scale_n_valid,+ SCALE_N=SCALE_N, BLOCK_SIZE_M=BSM, BLOCK_SIZE_N=32,+ NUM_ITER=1, NUM_STAGES=1, MXFP4_QUANT_BLOCK_SIZE=32,+ num_warps=1, waves_per_eu=0, num_stages=1,+ )++ result = aiter.gemm_a4w4(+ x_fp4.view(_fp4x2), B_shuffle,+ bs_sh.view(_fp8_e8m0), B_scale_sh,+ dtype=_bf16, bpreshuffle=True,+ )++ # Get ASM function+ try:+ _gemm_asm = torch.ops.aiter.gemm_a4w4_asm+ except Exception:+ try:+ import aiter.jit.core as _jc+ _gemm_asm = getattr(_jc, 'gemm_a4w4_asm', None)+ except Exception:+ pass++ # CRITICAL: swap custom_kernel to the hot path+ # This eliminates the warmup check from ALL future calls+ custom_kernel = _hot_dispatch++ return result+++ # Start with warmup - gets swapped to _hot_dispatch after first call+ custom_kernel = _warmup_kernel
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