Files
pytorch/torch/_inductor/kernel/mm.py
Gabriel Ferns 66f3b4a682 Contiguous subgraph decomposition (#161241)
## Summary

Adds a subgraph decomposition for addmm and mm that performs well on large `K` compared to `M` and `N`, and functions well as an alternative to `split-k` on AMD (transposed only), which does not support AMD currently.

## Background

On AMD (MI300x), for a matmul A * B, if B is non-contiguous, the resulting matmul is quite a bit slower.
For example:
```
  args[0]: TensorBox(StorageBox(
    InputBuffer(name='arg0_1', layout=FixedLayout('cuda:0', torch.float16, size=[1024, 178176], stride=[178176, 1]))
  ))
  args[1]: TensorBox(StorageBox(
    InputBuffer(name='arg1_1', layout=FixedLayout('cuda:0', torch.float16, size=[178176, 6144], stride=[1, 178176]))
  ))
```
is a lot slower than:
```
  args[0]: TensorBox(StorageBox(
    InputBuffer(name='arg0_1', layout=FixedLayout('cuda:0', torch.float16, size=[1024, 178176], stride=[178176, 1]))
  ))
  args[1]: TensorBox(StorageBox(
    InputBuffer(name='arg1_1', layout=FixedLayout('cuda:0', torch.float16, size=[178176, 6144], stride=[6144, 1]))
  ))
```
This PR adds a subgraph decomposition to test out whether making B contiguous is faster than just using the normal kernels.

## Data

I ran this on unique non-contiguous shapes from torchbench/huggingface and got these speedups:
```
Parsed 420 unique shapes from benchmark output
addmm improvements when best:
  addmm_16448x512x2048: +0.14%
  addmm_128x2048x2048: +0.01%
  addmm_128x768x1000: +0.75%
  addmm_12672x3072x768: +1.08%
  addmm_512x768x32000: +0.62%
  addmm_12608x384x384: +0.00%
  addmm_4160x1024x4096: +0.90%
  addmm_16x768x2: +0.56%
  addmm_12608x3072x768: +0.09%
  addmm_64x4096x1000: +2.77%
  addmm_256x1024x512: +1.99%
  addmm_30x256x256: +1.12%
  addmm_100480x128x384: +0.91%
  addmm_6400x2048x512: +0.25%
  addmm_61568x1024x256: +0.08%
  addmm_1x768x768: +0.93%
  addmm_12544x384x384: +0.19%
  addmm_128x512x1000: +0.77%
  addmm_2048x128x128: +1.32%
  addmm_128x3072x1000: +0.24%
  addmm_7936x512x2048: +0.07%
  addmm_8192x512x2048: +0.33%
  addmm_64x1024x1000: +1.43%
  addmm_128x2304x1000: +0.01%
  addmm_32768x256x2: +0.75%
  addmm_64x384x1152: +0.79%
  addmm_64x640x1000: +0.01%
  addmm_100480x128x128: +0.87%
  addmm_1152x3072x768: +1.13%
  addmm_8192x256x2048: +1.40%
  addmm_4096x128x768: +0.01%
  addmm_128x2560x1000: +0.01%
  addmm_12544x2048x512: +0.43%
  addmm_200704x24x96: +0.14%
  addmm_8448x512x2048: +0.96%
  addmm_50176x256x1024: +0.62%
  addmm_4160x4096x1024: +0.22%
  addmm_4096x768x768: +0.32%
  addmm_220x2048x512: +0.56%
  addmm_8x2048x1000: +1.12%
  addmm_256x197951x512: +26.99%
  addmm_401536x64x192: +0.60%
  addmm_2040x2048x512: +0.47%
  addmm_512x1024x256: +1.32%
  addmm_128x4096x1000: +1.67%
  addmm_12672x768x768: +0.34%
  addmm_128x368x1000: +0.77%
  addmm_96x1280x1000: +0.01%
  addmm_12544x512x2048: +0.41%
  addmm_6272x320x1280: +0.76%
  addmm_12544x3072x768: +0.09%
  addmm_64x384x1000: +0.39%
mm improvements when best:
  mm_200704x128x512: +1.29%
  mm_663552x16x16: +0.80%
  mm_4096x768x768: +0.51%
  mm_131072x64x31: +0.24%
  mm_12544x1152x384: +0.11%
  mm_128x2048x2: +0.46%
  mm_262144x16x23: +0.62%
  mm_50176x576x192: +0.37%
  mm_131072x16x31: +0.26%
================================================================================
BENCHMARK ANALYSIS RESULTS
================================================================================

Operation: addmm
----------------------------------------
Total shapes analyzed: 247
Average Subgraph placement: 3.38
Median Subgraph placement: 2.0
Subgraph is best choice: 52/247 shapes (21.1%)
Average improvement when best: 1.15%
Median improvement when best: 0.58%
Largest improvement when best: +26.99%

Operation: bmm
----------------------------------------
Total shapes analyzed: 85
Average Subgraph placement: 24.00
Median Subgraph placement: 21.0
Subgraph is best choice: 0/85 shapes (0.0%)
Average improvement when best: N/A (never best)
Median improvement when best: N/A (never best)
Largest improvement when best: N/A (never best)

Operation: mm
----------------------------------------
Total shapes analyzed: 88
Average Subgraph placement: 15.08
Median Subgraph placement: 4.0
Subgraph is best choice: 9/88 shapes (10.2%)
Average improvement when best: 0.52%
Median improvement when best: 0.46%
Largest improvement when best: +1.29%

```

## Results

The largest shape gain, `256,197951,512`, seemed to be driven by a case where the extern kernel is way faster than the best triton configs on the recursive autotune:
```
addmm,Extern,extern_kernels.addmm,256,197951,512,0.38024500012397766
addmm,Triton,256,197951,512,32,256,16,2,2,4,2.005444049835205
addmm,Triton,256,197951,512,32,128,32,2,4,8,2.04189395904541
addmm,Triton,256,197951,512,64,128,16,2,4,8,2.1911399364471436
addmm,Triton,256,197951,512,64,128,32,2,4,8,2.496040105819702
addmm,Triton,256,197951,512,64,128,64,2,8,16,2.9306790828704834
addmm,Triton,256,197951,512,64,64,32,2,4,8,3.0347819328308105
...
```
Compared to the non-transposed autotune:
```
addmm,Subgraph,contiguous_addmm_1384,256,197951,512,0.5024129748344421
addmm,Extern,extern_kernels.addmm,256,197951,512,0.6881489753723145
addmm,Triton,256,197951,512,32,256,16,2,2,4,2.5115010738372803
addmm,Triton,256,197951,512,32,128,32,2,4,8,2.5167479515075684
addmm,Triton,256,197951,512,64,128,16,2,4,8,2.9507460594177246
addmm,Triton,256,197951,512,64,256,64,2,8,4,2.9673290252685547
addmm,Triton,256,197951,512,64,128,64,2,8,16,3.3906331062316895
addmm,Triton,256,197951,512,64,128,32,2,4,8,3.496859073638916
```

It seems to perform really well for high values of `K` vs `N` and `M`.
Testing this hypothesis with some custom shapes:
```
Parsed 64 unique shapes from benchmark output
addmm improvements when best:
  addmm_128x16384x128: +0.18%
  addmm_128x262144x256: +38.24%
  addmm_128x200000x512: +14.76%
  addmm_256x800000x128: +0.06%
  addmm_131072x128x256: +0.27%
  addmm_128x256x131072: +0.25%
  addmm_2048x200000x64: +12.45%
mm improvements when best:
  mm_128x16384x128: +0.18%
  mm_128x262144x256: +38.05%
  mm_128x200000x512: +9.47%
  mm_256x800000x128: +0.99%
  mm_512x6400000x256: +3.17%
  mm_524288x64x64: +0.29%
  mm_2048x200000x64: +11.19%
  mm_8192x1000000x256: +34.14%
  mm_128x4096x100000: +0.40%
  mm_128x3072x150000: +0.27%
================================================================================
BENCHMARK ANALYSIS RESULTS
================================================================================

Operation: addmm
----------------------------------------
Total shapes analyzed: 33
Average Subgraph placement: 4.39
Median Subgraph placement: 2.0
Subgraph is best choice: 7/33 shapes (21.2%)
Average improvement when best: 9.46%
Median improvement when best: 0.27%
Largest improvement when best: +38.24%

Operation: mm
----------------------------------------
Total shapes analyzed: 30
Average Subgraph placement: 7.63
Median Subgraph placement: 2.0
Subgraph is best choice: 10/30 shapes (33.3%)
Average improvement when best: 9.81%
Median improvement when best: 2.08%
Largest improvement when best: +38.05%

```
## Conclusion
Contiguous Subgraph Decompositionseems worthwhile for `mm` and `addmm`, but not `bmm`, and has a very large improvment on low `M`, low `N`, and high `K` shapes.

Data gathering scripts:
https://gist.github.com/exclamaforte/4a896c064d301b27bf5ca0a4f8fc3866

## Test Plan:
New unit tests.

Differential Revision: D80771648

Pull Request resolved: https://github.com/pytorch/pytorch/pull/161241
Approved by: https://github.com/eellison
2025-09-04 04:43:58 +00:00

1418 lines
45 KiB
Python

# mypy: allow-untyped-defs
import functools
import logging
from typing import Any, Optional
import torch
from torch._dynamo.utils import counters
from torch._inductor.autoheuristic.autoheuristic import AutoHeuristicSelectAlgorithm
from torch._inductor.autoheuristic.autoheuristic_utils import (
AHContext,
context_add_strides,
context_add_using_tf32,
mm_operations,
)
from torch._inductor.codegen.cpp_gemm_template import CppGemmTemplate
from torch._inductor.remote_gemm_autotune_cache import gen_best_config
from torch._inductor.virtualized import V
from torch.fx.experimental.proxy_tensor import make_fx
from torch.torch_version import TorchVersion
from .. import config as inductor_config
from ..codegen.cuda.gemm_template import CUTLASS2xGemmTemplate, CUTLASS3xGemmTemplate
from ..codegen.rocm.ck_tile_universal_gemm_template import CKTileGemmTemplate
from ..codegen.rocm.ck_universal_gemm_template import CKGemmTemplate
from ..codegen.subgraph import SubgraphChoiceCaller, SubgraphTemplate
from ..ir import Buffer, FlexibleLayout, is_triton, Layout
from ..kernel_inputs import MMKernelInputs
from ..lowering import (
add_layout_constraint,
constrain_to_fx_strides,
lowerings as L,
register_lowering,
)
from ..select_algorithm import (
autotune_select_algorithm,
ExternKernelChoice,
realize_inputs,
TritonTemplate,
)
from ..utils import (
_use_cutlass_for_op,
use_aten_gemm_kernels,
use_ck_gemm_template,
use_ck_tile_gemm_template,
use_contiguous,
use_cpp_gemm_template,
use_cutlass_template,
use_decompose_k_choice,
use_triton_template,
use_triton_tma_template,
)
from .mm_common import _is_static_problem, mm_args, mm_grid, persistent_mm_grid
try:
import triton
triton_version = TorchVersion(triton.__version__)
has_triton = True
except ImportError:
triton_version = TorchVersion("0.0.0")
has_triton = False
log = logging.getLogger(__name__)
aten = torch.ops.aten
prims = torch.ops.prims
mm_template = TritonTemplate(
name="mm",
grid=mm_grid,
source=(
r"""
{{def_kernel("A", "B")}}
M = {{size("A", 0)}}
N = {{size("B", 1)}}
K = {{size("A", 1)}}
if M * N == 0:
# early exit due to zero-size input(s)
return
stride_am = {{stride("A", 0)}}
stride_ak = {{stride("A", 1)}}
stride_bk = {{stride("B", 0)}}
stride_bn = {{stride("B", 1)}}
# based on triton.ops.matmul
pid = tl.program_id(0)
grid_m = (M + BLOCK_M - 1) // BLOCK_M
grid_n = (N + BLOCK_N - 1) // BLOCK_N
# re-order program ID for better L2 performance
width = GROUP_M * grid_n
group_id = pid // width
group_size = min(grid_m - group_id * GROUP_M, GROUP_M)
pid_m = group_id * GROUP_M + (pid % group_size)
pid_n = (pid % width) // (group_size)
tl.assume(pid_m >= 0)
tl.assume(pid_n >= 0)
rm = pid_m * BLOCK_M + tl.arange(0, BLOCK_M)
rn = pid_n * BLOCK_N + tl.arange(0, BLOCK_N)
if ((stride_am == 1 and stride_ak == M) or (stride_am == K and stride_ak == 1)) and (M >= BLOCK_M and K > 1):
offs_a_m = tl.max_contiguous(tl.multiple_of(rm % M, BLOCK_M), BLOCK_M)
else:
offs_a_m = rm % M
if ((stride_bk == 1 and stride_bn == K) or (stride_bk == N and stride_bn == 1)) and (N >= BLOCK_N and K > 1):
offs_b_n = tl.max_contiguous(tl.multiple_of(rn % N, BLOCK_N), BLOCK_N)
else:
offs_b_n = rn % N
offs_k = tl.arange(0, BLOCK_K)
acc = tl.zeros((BLOCK_M, BLOCK_N), dtype=ACC_TYPE)
for k_idx in range(0, tl.cdiv(K, BLOCK_K)):
{% if not EVEN_K %}
a_mask = offs_k[None, :] < (K - k_idx * BLOCK_K)
b_mask = offs_k[:, None] < (K - k_idx * BLOCK_K)
{% endif %}
a_k_idx_vals = offs_k[None, :] + (k_idx * BLOCK_K)
b_k_idx_vals = offs_k[:, None] + (k_idx * BLOCK_K)
idx_m = offs_a_m[:, None]
idx_n = a_k_idx_vals
{{load_input("A", "a", ("idx_m", "idx_n"), mask=None if EVEN_K else "a_mask", indent_width=8)}}
idx_m = b_k_idx_vals
idx_n = offs_b_n[None, :]
{{load_input("B", "b", ("idx_m", "idx_n"), mask=None if EVEN_K else "b_mask", indent_width=8)}}
{% if USE_FAST_ACCUM %}
acc = tl.dot(a, b, acc, allow_tf32=ALLOW_TF32, out_dtype=ACC_TYPE)
{% else %}
acc += tl.dot(a, b, allow_tf32=ALLOW_TF32, out_dtype=ACC_TYPE)
{% endif %}
# rematerialize rm and rn to save registers
rm = pid_m * BLOCK_M + tl.arange(0, BLOCK_M)
rn = pid_n * BLOCK_N + tl.arange(0, BLOCK_N)
idx_m = rm[:, None]
idx_n = rn[None, :]
mask = (idx_m < M) & (idx_n < N)
# inductor generates a suffix
{{store_output(("idx_m", "idx_n"), "acc", "mask")}}
"""
if (torch.version.hip is None) or triton_version >= "3.3.0"
# FIXME: To get around rocm failures like https://github.com/pytorch/pytorch/actions/runs/13123783322/job/36617154943
# The only difference between the two templates is M >= BLOCK_M and N >= BLOCK_N checking.
# See more details in https://github.com/pytorch/pytorch/pull/146293
else r"""
{{def_kernel("A", "B")}}
M = {{size("A", 0)}}
N = {{size("B", 1)}}
K = {{size("A", 1)}}
if M * N == 0:
# early exit due to zero-size input(s)
return
stride_am = {{stride("A", 0)}}
stride_ak = {{stride("A", 1)}}
stride_bk = {{stride("B", 0)}}
stride_bn = {{stride("B", 1)}}
# based on triton.ops.matmul
pid = tl.program_id(0)
grid_m = (M + BLOCK_M - 1) // BLOCK_M
grid_n = (N + BLOCK_N - 1) // BLOCK_N
# re-order program ID for better L2 performance
width = GROUP_M * grid_n
group_id = pid // width
group_size = min(grid_m - group_id * GROUP_M, GROUP_M)
pid_m = group_id * GROUP_M + (pid % group_size)
pid_n = (pid % width) // (group_size)
tl.assume(pid_m >= 0)
tl.assume(pid_n >= 0)
rm = pid_m * BLOCK_M + tl.arange(0, BLOCK_M)
rn = pid_n * BLOCK_N + tl.arange(0, BLOCK_N)
if (stride_am == 1 and stride_ak == M) or (stride_am == K and stride_ak == 1):
offs_a_m = tl.max_contiguous(tl.multiple_of(rm % M, BLOCK_M), BLOCK_M)
else:
offs_a_m = rm % M
if (stride_bk == 1 and stride_bn == K) or (stride_bk == N and stride_bn == 1):
offs_b_n = tl.max_contiguous(tl.multiple_of(rn % N, BLOCK_N), BLOCK_N)
else:
offs_b_n = rn % N
offs_k = tl.arange(0, BLOCK_K)
acc = tl.zeros((BLOCK_M, BLOCK_N), dtype=ACC_TYPE)
for k_idx in range(0, tl.cdiv(K, BLOCK_K)):
{% if not EVEN_K %}
a_mask = offs_k[None, :] < (K - k_idx * BLOCK_K)
b_mask = offs_k[:, None] < (K - k_idx * BLOCK_K)
{% endif %}
a_k_idx_vals = offs_k[None, :] + (k_idx * BLOCK_K)
b_k_idx_vals = offs_k[:, None] + (k_idx * BLOCK_K)
idx_m = offs_a_m[:, None]
idx_n = a_k_idx_vals
{{load_input("A", "a", ("idx_m", "idx_n"), mask=None if EVEN_K else "a_mask", indent_width=8)}}
idx_m = b_k_idx_vals
idx_n = offs_b_n[None, :]
{{load_input("B", "b", ("idx_m", "idx_n"), mask=None if EVEN_K else "b_mask", indent_width=8)}}
{% if USE_FAST_ACCUM %}
acc = tl.dot(a, b, acc, allow_tf32=ALLOW_TF32, out_dtype=ACC_TYPE)
{% else %}
acc += tl.dot(a, b, allow_tf32=ALLOW_TF32, out_dtype=ACC_TYPE)
{% endif %}
# rematerialize rm and rn to save registers
rm = pid_m * BLOCK_M + tl.arange(0, BLOCK_M)
rn = pid_n * BLOCK_N + tl.arange(0, BLOCK_N)
idx_m = rm[:, None]
idx_n = rn[None, :]
mask = (idx_m < M) & (idx_n < N)
# inductor generates a suffix
{{store_output(("idx_m", "idx_n"), "acc", "mask")}}
"""
),
cache_codegen_enabled_for_template=True,
prologue_loads_all_inputs=True,
)
persistent_tma_mm_template = TritonTemplate(
name="mm_persistent_tma",
grid=persistent_mm_grid,
source=r"""
{{def_kernel("A", "B")}}
M = {{size("A", 0)}}
N = {{size("B", 1)}}
K = {{size("A", 1)}}
if M * N == 0:
# early exit due to zero-size input(s)
return
start_pid = tl.program_id(0)
grid_m = tl.cdiv(M, BLOCK_M)
grid_n = tl.cdiv(N, BLOCK_N)
k_tiles = tl.cdiv(K, BLOCK_K)
num_tiles = grid_m * grid_n
tiles_per_SM = num_tiles // NUM_SMS
if start_pid < num_tiles % NUM_SMS:
tiles_per_SM += 1
tile_id = start_pid - NUM_SMS
ki = -1
width = GROUP_M * grid_n
rk_for_mask = tl.arange(0, BLOCK_K)
acc = tl.zeros((BLOCK_M, BLOCK_N), dtype=ACC_TYPE)
{%- if TMA_EXPERIMENTAL_API %}
workspace_base = ws_ptr + start_pid * 2 * TMA_SIZE
a_desc_ptr = workspace_base
b_desc_ptr = workspace_base + TMA_SIZE
triton.language.extra.cuda.experimental_device_tensormap_create2d(
desc_ptr=a_desc_ptr,
global_address=A,
load_size=[BLOCK_M, BLOCK_K] if A_ROW_MAJOR else [BLOCK_K, BLOCK_M],
global_size=[M, K] if A_ROW_MAJOR else [K, M],
element_ty=A.dtype.element_ty,
)
triton.language.extra.cuda.experimental_device_tensormap_create2d(
desc_ptr=b_desc_ptr,
global_address=B,
load_size=[BLOCK_K, BLOCK_N] if B_ROW_MAJOR else [BLOCK_N, BLOCK_K],
global_size=[K, N] if B_ROW_MAJOR else [N, K],
element_ty=B.dtype.element_ty,
)
tl.extra.cuda.experimental_tensormap_fenceproxy_acquire(a_desc_ptr)
tl.extra.cuda.experimental_tensormap_fenceproxy_acquire(b_desc_ptr)
{%- else %}
stride_am = {{stride("A", 0)}}
stride_ak = {{stride("A", 1)}}
stride_bk = {{stride("B", 0)}}
stride_bn = {{stride("B", 1)}}
a_desc = triton.language.make_tensor_descriptor(
base=A,
shape=[M, K] if A_ROW_MAJOR else [K, M],
strides=[stride_am, 1] if A_ROW_MAJOR else [stride_ak, 1],
block_shape=[BLOCK_M, BLOCK_K] if A_ROW_MAJOR else [BLOCK_K, BLOCK_M],
)
b_desc = triton.language.make_tensor_descriptor(
base=B,
shape=[K, N] if B_ROW_MAJOR else [N, K],
strides=[stride_bk, 1] if B_ROW_MAJOR else [stride_bn, 1],
block_shape=[BLOCK_K, BLOCK_N] if B_ROW_MAJOR else [BLOCK_N, BLOCK_K],
)
{%- endif %}
pid_m = 0
pid_n = 0
rm = 0
rn = 0
for _ in range(0, k_tiles * tiles_per_SM):
ki = tl.where(ki == k_tiles - 1, 0, ki + 1)
if ki == 0:
tile_id += NUM_SMS
# re-order program ID for better L2 performance
group_id = tile_id // width
group_size = min(grid_m - group_id * GROUP_M, GROUP_M)
pid_m = group_id * GROUP_M + (tile_id % group_size)
pid_n = (tile_id % width) // (group_size)
rm = pid_m * BLOCK_M
rn = pid_n * BLOCK_N
rk = ki * BLOCK_K
{%- if TMA_EXPERIMENTAL_API %}
a = tl._experimental_descriptor_load(
a_desc_ptr,
[rm, rk] if A_ROW_MAJOR else [rk, rm],
[BLOCK_M, BLOCK_K] if A_ROW_MAJOR else [BLOCK_K, BLOCK_M],
A.dtype.element_ty,
)
b = tl._experimental_descriptor_load(
b_desc_ptr,
[rk, rn] if B_ROW_MAJOR else [rn, rk],
[BLOCK_K, BLOCK_N] if B_ROW_MAJOR else [BLOCK_N, BLOCK_K],
B.dtype.element_ty,
)
{%- else %}
a = tl.load_tensor_descriptor(
a_desc,
[rm, rk] if A_ROW_MAJOR else [rk, rm],
)
b = tl.load_tensor_descriptor(
b_desc,
[rk, rn] if B_ROW_MAJOR else [rn, rk],
)
{%- endif %}
acc += tl.dot(
a if A_ROW_MAJOR else a.T,
b if B_ROW_MAJOR else b.T,
allow_tf32=ALLOW_TF32,
)
if ki == k_tiles - 1:
# rematerialize rm and rn to save registers
rcm = rm + tl.arange(0, BLOCK_M)
rcn = rn + tl.arange(0, BLOCK_N)
idx_m = rcm[:, None]
idx_n = rcn[None, :]
mask = (idx_m < M) & (idx_n < N)
# inductor generates a suffix
{{store_output(("idx_m", "idx_n"), "acc", "mask", indent_width=12)}}
acc = tl.zeros((BLOCK_M, BLOCK_N), dtype=ACC_TYPE)
""",
)
load_scales = r"""
@triton.jit
def load_scales(a_scale_ptr, b_scale_ptr, SCALING_ROWWISE: tl.constexpr):
if SCALING_ROWWISE:
# For row-wise scaling, we'll return the pointers
return a_scale_ptr, b_scale_ptr
else:
# For per-tensor scaling, we'll load the scalar values
a_scale = tl.load(a_scale_ptr)
b_scale = tl.load(b_scale_ptr)
return a_scale, b_scale
"""
apply_scaling = r"""
@triton.jit
def apply_scaling(
accumulator,
a_scale,
b_scale,
SCALING_ROWWISE: tl.constexpr,
offs_cm,
offs_cn,
M,
N,
stride_a_scale_m,
stride_b_scale_n,
):
if SCALING_ROWWISE:
# For row-wise scaling, we need to load the scales for each row/column
a_scales = tl.load(
a_scale + (offs_cm * stride_a_scale_m),
mask=offs_cm < M,
other=0.0,
)
b_scales = tl.load(
b_scale + (offs_cn * stride_b_scale_n),
mask=offs_cn < N,
other=0.0,
)
acc_scale = a_scales[:, None] * b_scales[None, :]
else:
# For per-tensor scaling, we can directly use the loaded scalar values
acc_scale = a_scale * b_scale
return accumulator * acc_scale
"""
device_tma = r"""
{{def_kernel("A", "B", "A_inverse_scale", "B_inverse_scale")}}
M = {{size("A", 0)}}
N = {{size("B", 1)}}
K = {{size("A", 1)}}
if M * N == 0:
# early exit due to zero-size input(s)
return
stride_am = {{stride("A", 0)}}
stride_ak = {{stride("A", 1)}}
stride_bk = {{stride("B", 0)}}
stride_bn = {{stride("B", 1)}}
if SCALING_ROWWISE:
stride_a_scale_m = 1
stride_b_scale_n = 1
else:
stride_a_scale_m = 0
stride_b_scale_n = 0
start_pid = tl.program_id(axis=0)
num_pid_m = tl.cdiv(M, BLOCK_M)
num_pid_n = tl.cdiv(N, BLOCK_N)
k_tiles = tl.cdiv(K, BLOCK_K)
num_tiles = num_pid_m * num_pid_n
{%- if TMA_EXPERIMENTAL_API %}
workspace_base = ws_ptr + start_pid * 2 * TMA_SIZE
a_desc_ptr = workspace_base
b_desc_ptr = workspace_base + TMA_SIZE
triton.language.extra.cuda.experimental_device_tensormap_create2d(
desc_ptr=a_desc_ptr,
global_address=A,
load_size=[BLOCK_M, BLOCK_K],
global_size=[M, K],
element_ty=A.dtype.element_ty,
)
triton.language.extra.cuda.experimental_device_tensormap_create2d(
desc_ptr=b_desc_ptr,
global_address=B,
load_size=[BLOCK_N, BLOCK_K],
global_size=[N, K],
element_ty=B.dtype.element_ty,
)
tl.extra.cuda.experimental_tensormap_fenceproxy_acquire(a_desc_ptr)
tl.extra.cuda.experimental_tensormap_fenceproxy_acquire(b_desc_ptr)
{%- else %}
stride_am = {{stride("A", 0)}}
stride_bn = {{stride("B", 1)}}
a_desc = triton.language.make_tensor_descriptor(
base=A,
shape=[M, K],
strides=[stride_am, 1],
block_shape=[BLOCK_M, BLOCK_K],
)
b_desc = triton.language.make_tensor_descriptor(
base=B,
shape=[N, K],
strides=[stride_bn, 1],
block_shape=[BLOCK_N, BLOCK_K],
)
{%- endif %}
tiles_per_SM = num_tiles // NUM_SMS
if start_pid < num_tiles % NUM_SMS:
tiles_per_SM += 1
tile_id = start_pid - NUM_SMS
ki = -1
pid_m = 0
pid_n = 0
offs_am = 0
offs_bn = 0
num_pid_in_group = GROUP_M * num_pid_n
accumulator = tl.zeros((BLOCK_M, BLOCK_N), dtype=ACC_TYPE)
a_scale, b_scale = load_scales(A_inverse_scale, B_inverse_scale, SCALING_ROWWISE)
for _ in range(0, k_tiles * tiles_per_SM):
ki = tl.where(ki == k_tiles - 1, 0, ki + 1)
if ki == 0:
tile_id += NUM_SMS
group_id = tile_id // num_pid_in_group
first_pid_m = group_id * GROUP_M
group_size_m = min(num_pid_m - first_pid_m, GROUP_M)
pid_m = first_pid_m + (tile_id % group_size_m)
pid_n = (tile_id % num_pid_in_group) // group_size_m
offs_am = pid_m * BLOCK_M
offs_bn = pid_n * BLOCK_N
offs_k = ki * BLOCK_K
{%- if TMA_EXPERIMENTAL_API %}
a = tl._experimental_descriptor_load(
a_desc_ptr, [offs_am, offs_k], [BLOCK_M, BLOCK_K], A.dtype.element_ty
)
b = tl._experimental_descriptor_load(
b_desc_ptr, [offs_bn, offs_k], [BLOCK_N, BLOCK_K], B.dtype.element_ty
)
{%- else %}
a = tl.load_tensor_descriptor(a_desc, [offs_am, offs_k])
b = tl.load_tensor_descriptor(b_desc, [offs_bn, offs_k])
{%- endif %}
if USE_FAST_ACCUM:
accumulator = tl.dot(a, b.T, accumulator)
else:
accumulator += tl.dot(a, b.T)
if ki == k_tiles - 1:
# Apply inverse scaling
offs_cm = offs_am + tl.arange(0, BLOCK_M)
offs_cn = offs_bn + tl.arange(0, BLOCK_N)
# Apply scaling
accumulator = apply_scaling(
accumulator,
a_scale,
b_scale,
SCALING_ROWWISE,
offs_cm,
offs_cn,
M,
N,
stride_a_scale_m,
stride_b_scale_n,
)
idx_m = offs_cm[:, None]
idx_n = offs_cn[None, :]
mask = (idx_m < M) & (idx_n < N)
# inductor generates a suffix
{{store_output(("idx_m", "idx_n"), "accumulator", "mask", indent_width=12)}}
accumulator = tl.zeros((BLOCK_M, BLOCK_N), dtype=tl.float32)
"""
scaled_mm_device_tma_template = TritonTemplate(
name="scaled_mm_device_tma",
grid=persistent_mm_grid,
source=device_tma + load_scales + apply_scaling,
)
# prevent duplication registration of extern functions
@functools.cache
def lazy_register_extern_choice(fn):
return ExternKernelChoice(fn)
aten_mm = ExternKernelChoice(torch.mm, "at::mm_out", op_overload=aten.mm.out)
aten_addmm = ExternKernelChoice(
torch.addmm, "at::addmm_out", op_overload=aten.addmm.out
)
aten__int_mm = ExternKernelChoice(
torch._int_mm, "at::_int_mm_out", op_overload=aten._int_mm.out
)
aten__sparse_semi_structured_mm = ExternKernelChoice(
torch._sparse_semi_structured_mm,
"at::_sparse_semi_structured_mm",
has_out_variant=False,
op_overload=aten._sparse_semi_structured_mm.default,
)
aten__fp8_mm = ExternKernelChoice(
torch._scaled_mm, "at::_scaled_mm_out", op_overload=aten._scaled_mm.out
)
def _is_int8_mat(mat):
return mat.get_dtype() in (torch.int8, torch.uint8)
def bias_addmm(inp, mat1, mat2, *, out=None, alpha=1, beta=1):
"""
Giving torch.addmm a 1D tensor calls a different (faster) cublasLt
kernel under the hood. There are a few shapes where this is slower,
but they are rare.
"""
if inp.stride(0) == 0 or inp.size(0) == 1:
return torch.addmm(inp[0], mat1, mat2, out=out, alpha=alpha, beta=beta)
return torch.addmm(inp, mat1, mat2, out=out, alpha=alpha, beta=beta)
def check_supported_striding(mat_a, mat_b) -> None:
def is_row_major(stride) -> bool:
return V.graph.sizevars.statically_known_equals(stride[1], 1)
def is_col_major(stride) -> bool:
return V.graph.sizevars.statically_known_equals(stride[0], 1)
def has_zero_dim(size) -> bool:
return bool(
V.graph.sizevars.statically_known_equals(size[0], 0)
or V.graph.sizevars.statically_known_equals(size[1], 0)
)
# Check mat_a (self) stride requirements
torch._check(
is_row_major(mat_a.get_stride()) or has_zero_dim(mat_a.get_size()),
lambda: f"mat_a must be row_major, got stride {mat_a.get_stride()}",
)
# Check mat_b stride requirements
torch._check(
is_col_major(mat_b.get_stride()) or has_zero_dim(mat_b.get_size()),
lambda: f"mat_b must be col_major, got stride {mat_b.get_stride()}",
)
aten_bias_addmm = ExternKernelChoice(bias_addmm, None)
def decomposeK(a, b, k_splits):
m = a.shape[0]
n = b.shape[1]
k = a.shape[1]
k_parts = k // k_splits
B = k_splits
a_reshaped = torch.permute(a.reshape(m, B, k_parts), (1, 0, 2))
b_reshaped = b.reshape(B, k_parts, n)
result = torch.bmm(a_reshaped, b_reshaped, out_dtype=torch.float32)
reduced_buf = torch.sum(result, 0)
return reduced_buf.to(a.dtype)
class DecomposeKSugraphTemplate(SubgraphTemplate):
def __init__(self):
super().__init__(
name="decompose_k",
)
def generate( # type: ignore[override]
self,
input_nodes: list[Buffer],
layout: Layout,
k_split: int,
) -> SubgraphChoiceCaller:
from torch._dispatch.python import enable_python_dispatcher
from ..decomposition import select_decomp_table
name = f"decompose_k_mm_{k_split}_split"
description = f"{k_split=}"
with enable_python_dispatcher():
decompositions = select_decomp_table()
fn = make_fx(
functools.partial(decomposeK, k_splits=k_split),
decompositions,
)
return super().generate(
name=name,
input_nodes=input_nodes,
layout=layout,
make_fx_graph=fn,
description=description,
)
decompose_k_subgraph_template = DecomposeKSugraphTemplate()
class ContiguousTemplate(SubgraphTemplate):
def __init__(self, name: str, description: str, fn: Any):
self.name = name
self.description = description
self.fn = fn
super().__init__(
name=name,
)
def generate( # type: ignore[override]
self,
input_nodes: list[Buffer],
layout: Layout,
) -> SubgraphChoiceCaller:
from torch._dispatch.python import enable_python_dispatcher
from ..decomposition import select_decomp_table
with enable_python_dispatcher():
decompositions = select_decomp_table()
fn = make_fx(
self.fn,
decompositions,
)
return super().generate(
name=self.name,
input_nodes=input_nodes,
layout=layout,
make_fx_graph=fn,
description=self.description,
)
def contiguous_mm(a, b):
return torch.mm(a, b.contiguous())
def contiguous_addmm(inp, a, b):
return torch.addmm(inp, a, b.contiguous())
mm_contiguous_subgraph_template = ContiguousTemplate(
"contiguous_mm", "contiguous mm", contiguous_mm
)
addmm_contiguous_subgraph_template = ContiguousTemplate(
"contiguous_addmm", "contiguous addmm", contiguous_addmm
)
@register_lowering(aten.mm, type_promotion_kind=None)
def tuned_mm(mat1, mat2, *, layout=None):
"""
Lowering for autotuning aten.mm with different backends (Aten, Triton, CUTLASS, etc.)
"""
# TODO(coconutruben): integrate into MMKernelInputs when all callsites use that
m, n, k, layout, mat1, mat2 = mm_args(mat1, mat2, layout=layout)
static_shape, is_nonzero = _is_static_problem(layout)
name = "mm"
# Create MMKernelInputs for standard MM at the top
kernel_inputs = MMKernelInputs([mat1, mat2])
# below is for getting an overview logging info of inductor mms
counters["aten_mm_info"][f"aten.mm_{m}_{n}_{k}"] += 1
log.info(
"Tuned aten.mm: m=%s, n=%s, k=%s, mat1_dtype=%s, mat2_dtype=%s, output_layout=%s",
m,
n,
k,
mat1.get_dtype(),
mat2.get_dtype(),
layout,
)
aten_layout = layout
if not (inductor_config.max_autotune or inductor_config.max_autotune_gemm):
aten_layout = FlexibleLayout(
device=layout.device, dtype=layout.dtype, size=layout.size
)
# options to tune from
choices = (
[aten_mm.bind(kernel_inputs.nodes(), aten_layout)]
if use_aten_gemm_kernels()
else []
)
static_shape, is_nonzero = _is_static_problem(layout)
if is_nonzero and use_triton_template(layout):
# Get template params using the new unified function
for kwargs, extra_kwargs in V.choices.get_mm_configs(
kernel_inputs, layout, mm_template.name, "mm"
):
mm_template.maybe_append_choice(
choices,
**kwargs,
**extra_kwargs,
)
if use_triton_tma_template(mat1, mat2):
# Get TMA template params using the new unified function
for kwargs, extra_kwargs in V.choices.get_mm_configs(
kernel_inputs, layout, persistent_tma_mm_template.name, "mm"
):
persistent_tma_mm_template.maybe_append_choice(
choices,
**kwargs,
**extra_kwargs,
)
# Only do split-k optimization if K is much larger than m, n and m, n are small
if use_decompose_k_choice(m, n, k):
for kwargs, extra_kwargs in V.choices.get_mm_configs(
kernel_inputs, layout, decompose_k_subgraph_template.name, "mm"
):
decompose_k_subgraph_template.maybe_append_choice(
choices,
**kwargs,
**extra_kwargs,
)
if not mat2.get_layout().is_contiguous() and use_contiguous(m, n, k):
mm_contiguous_subgraph_template.maybe_append_choice(
choices,
input_nodes=(mat1, mat2),
layout=layout,
)
if (
is_nonzero
and use_cutlass_template(layout, m, n, k)
and _use_cutlass_for_op("mm")
):
CUTLASS3xGemmTemplate.add_cutlass_gemm_choices(
choices, layout, kernel_inputs.nodes()
)
if is_nonzero and use_ck_gemm_template(layout, m, n, k):
CKGemmTemplate.add_ck_gemm_choices(choices, layout, kernel_inputs.nodes())
if is_nonzero and use_ck_tile_gemm_template(layout, m, n, k):
CKTileGemmTemplate.add_choices(choices, layout, kernel_inputs.nodes())
if use_cpp_gemm_template(layout, mat1, mat2):
CppGemmTemplate.add_choices(
choices,
layout,
kernel_inputs.nodes(),
)
input_nodes = [mat1, mat2]
if (
is_nonzero
and use_triton_template(layout)
and torch._inductor.config.run_autoheuristic(name)
and is_triton(mat1)
):
always_included = []
if use_aten_gemm_kernels():
always_included.append("extern_mm")
num_choices_before_extra_configs = len(choices)
for kwargs, extra_kwargs in V.choices.get_mm_configs(
# TODO(coconutruben): remove once we deprecate ah
# mm-extra is a hack to keep the ah functionality alive
# while we transition to the unified kwargs retrieval
kernel_inputs,
layout,
"mm-ah",
"mm",
):
assert not kwargs, "mm-ah should not have any extra kwargs"
mm_template.maybe_append_choice(
choices,
input_nodes=kernel_inputs.nodes(),
layout=layout,
**kwargs,
)
# using AutoHeuristic for ranking
ah_choices = mm_autoheuristic(
mat1,
mat2,
m,
n,
k,
choices,
name,
input_nodes,
mm_operations(),
None,
top_k=10,
always_included=always_included,
)
if not torch._inductor.config.collect_autoheuristic(name):
# if we are collecting data, we do not want to modify choices
if ah_choices is not None and len(ah_choices) > 0:
# the order in which autoheuristic returns choices is not the same as
# as the order of choices, which affects things like epilogue fusion.
# once epilogue fusion benchmarks choices in sorted order, I think we can
# just use the order returned by autoheuristic
choices = [choice for choice in choices if choice in ah_choices]
else:
choices = choices[:num_choices_before_extra_configs]
for k in inductor_config.external_matmul:
choices.append(
lazy_register_extern_choice(k).bind(kernel_inputs.nodes(), layout)
)
best_config_future = None
# Purposely not awaiting the future here - this kicks off the best config lookup at lowering time
# The future will be awaited at scheduling time in select_algorithm.py
if torch._inductor.config.remote_gemm_autotune_cache:
best_config_future = gen_best_config(mat1, mat2)
return autotune_select_algorithm(
name,
choices,
kernel_inputs.nodes(),
layout,
best_config_future=best_config_future,
)
@register_lowering(aten._int_mm, type_promotion_kind=None)
def tuned_int_mm(mat1, mat2, *, layout=None):
# TODO(coconutruben): integrate into MMKernelInputs when all callsites use that
m, n, k, layout, mat1, mat2 = mm_args(
mat1, mat2, layout=layout, out_dtype=torch.int32
)
# below is for getting an overview logging info of inductor mms
counters["aten_mm_info"][f"aten._int_mm_{m}_{n}_{k}"] += 1
log.info(
"Tuned aten._int_mm: m=%s, n=%s, k=%s, mat1_dtype=%s, mat2_dtype=%s, output_layout=%s",
m,
n,
k,
mat1.get_dtype(),
mat2.get_dtype(),
layout,
)
static_shape, is_nonzero = _is_static_problem(layout)
use_cutlass = static_shape and is_nonzero and use_cutlass_template(layout, m, n, k)
choices = (
[aten__int_mm.bind((mat1, mat2), layout)] if use_aten_gemm_kernels() else []
)
# Create MMKernelInputs for Int MM
kernel_inputs = MMKernelInputs([mat1, mat2])
if use_cutlass and _use_cutlass_for_op("int_mm"):
CUTLASS3xGemmTemplate.add_cutlass_gemm_choices(
choices, layout, kernel_inputs.nodes(), fuseable=True, non_fuseable=True
)
if is_nonzero and use_triton_template(layout, enable_int32=True):
for kwargs, extra_kwargs in V.choices.get_mm_configs(
kernel_inputs, layout, mm_template.name, "int_mm"
):
mm_template.maybe_append_choice(
choices,
**kwargs,
**extra_kwargs,
)
return autotune_select_algorithm("int_mm", choices, kernel_inputs.nodes(), layout)
@register_lowering(aten.addmm, type_promotion_kind=None)
def tuned_addmm(inp, mat1, mat2, *, alpha=1, beta=1, layout=None):
"""
Lowering for autotuning aten.addmm with different backends (Aten, Triton, CUTLASS, etc.)
"""
# TODO(coconutruben): integrate into MMKernelInputs when all callsites use that
m, n, k, layout, mat1, mat2, inp_expanded = mm_args(mat1, mat2, inp, layout=layout)
static_shape, is_nonzero = _is_static_problem(layout)
# Create MMKernelInputs for AddMM at the top
kernel_inputs = MMKernelInputs(
[inp_expanded, mat1, mat2], scalars=dict(alpha=alpha, beta=beta)
)
# below is for getting an overview logging info of inductor mms
counters["aten_mm_info"][f"aten.addmm_{m}_{n}_{k}"] += 1
log.info(
"Tuned aten.addmm: m=%s, n=%s, k=%s, mat1_dtype=%s, mat2_dtype=%s, output_layout=%s",
m,
n,
k,
mat1.get_dtype(),
mat2.get_dtype(),
layout,
)
if (not is_nonzero) or (
not (inductor_config.max_autotune or inductor_config.max_autotune_gemm)
):
# Use a FlexibleLayout if we are not autotuning.
# This allows padding strides for the output.
from torch._inductor.ir import FixedLayout, FlexibleLayout
if isinstance(layout, FixedLayout):
layout = FlexibleLayout(
device=layout.device, dtype=layout.dtype, size=layout.size
)
choices = (
[
aten_addmm.bind(
# TODO(coconutruben): replace with kernel_inputs.nodes()
# once that supports the unexpanded nodes as well
[inp, mat1, mat2],
layout,
alpha=alpha,
beta=beta,
)
]
if use_aten_gemm_kernels()
else []
)
return autotune_select_algorithm(
# TODO(coconutruben): replace with kernel_inputs.nodes()
# once that supports the unexpanded nodes as well
"addmm",
choices,
[inp, mat1, mat2],
layout,
)
choices = (
[
aten_addmm.bind(
kernel_inputs.nodes(),
layout,
alpha=alpha,
beta=beta,
)
]
if use_aten_gemm_kernels()
else []
)
if (
use_aten_gemm_kernels()
and inp_expanded.get_stride()[0] == 0
and inp_expanded.get_device().type == "cuda"
and inductor_config.triton.autotune_cublasLt
):
# unexpand inp to make sure fused addmm from cublasLt is used
choices.insert(
0,
aten_bias_addmm.bind(
kernel_inputs.nodes(),
layout,
alpha=alpha,
beta=beta,
),
)
if is_nonzero and use_triton_template(layout):
# all the triton templates use the extra_kwargs
# Get template params using the new unified function
for kwargs, extra_kwargs in V.choices.get_mm_configs(
kernel_inputs,
layout,
mm_template.name,
"addmm",
):
mm_template.maybe_append_choice(
choices,
**kwargs,
**extra_kwargs,
)
if use_triton_tma_template(mat1, mat2):
# Get TMA template params using the new unified function
for kwargs, extra_kwargs in V.choices.get_mm_configs(
kernel_inputs,
layout,
persistent_tma_mm_template.name,
"addmm",
):
persistent_tma_mm_template.maybe_append_choice(
choices,
**kwargs,
**extra_kwargs,
)
if not mat2.get_layout().is_contiguous() and use_contiguous(m, n, k):
addmm_contiguous_subgraph_template.maybe_append_choice(
choices,
input_nodes=(inp_expanded, mat1, mat2),
layout=layout,
)
if (
is_nonzero
and use_cutlass_template(layout, m, n, k)
and _use_cutlass_for_op("addmm")
):
CUTLASS3xGemmTemplate.add_cutlass_gemm_choices(
choices,
layout,
# reorder here because CUTLASS expects (x, w, bias) but torch
# is bias, x, w
kernel_inputs.nodes(reorder=[1, 2, 0]),
alpha=alpha,
beta=beta,
)
if is_nonzero and use_ck_gemm_template(layout, m, n, k):
CKGemmTemplate.add_ck_gemm_choices(
choices,
layout,
# reorder here because CK expects (x, w, bias) but torch
# is bias, x, w
kernel_inputs.nodes(reorder=[1, 2, 0]),
alpha=alpha,
beta=beta,
input_reorder=[2, 0, 1],
)
if use_cpp_gemm_template(layout, mat1, mat2):
CppGemmTemplate.add_choices(
choices,
layout,
kernel_inputs.nodes(),
alpha=alpha,
beta=beta,
has_bias=True,
)
return autotune_select_algorithm("addmm", choices, kernel_inputs.nodes(), layout)
@register_lowering(aten._sparse_semi_structured_mm, type_promotion_kind=None)
def tuned_sparse_semi_structured_mm(
mat1, mat1_meta, mat2, *, out_dtype=None, layout=None
):
from torch._inductor.select_algorithm import realize_inputs
mat1, mat1_meta, mat2 = realize_inputs(mat1, mat1_meta, mat2)
m1, k1 = mat1.get_size()
m2, _ = mat1_meta.get_size()
k2, n = mat2.get_size()
m = V.graph.sizevars.check_equals_and_simplify(m1, m2)
k = V.graph.sizevars.check_equals_and_simplify(2 * k1, k2)
if layout is None:
from torch._inductor.ir import FixedLayout
layout = FixedLayout(
mat2.get_device(),
out_dtype if out_dtype else mat2.get_dtype(),
[m, n],
[n, 1],
)
else:
assert out_dtype is None, "out_dtype is ignored if layout is specified."
choices = (
[
aten__sparse_semi_structured_mm.bind(
(mat1, mat1_meta, mat2), layout, out_dtype=out_dtype
)
]
if use_aten_gemm_kernels()
else []
)
if (
m * n != 0
and use_cutlass_template(layout, m, n, k)
and _use_cutlass_for_op("sparse_semi_structured_mm")
):
CUTLASS2xGemmTemplate.add_cutlass_gemm_choices(
choices, layout, [mat1, mat2, mat1_meta], fuseable=True, non_fuseable=True
)
return autotune_select_algorithm(
"sparse_semi_structured_mm", choices, (mat1, mat1_meta, mat2), layout
)
add_layout_constraint(aten._scaled_mm.default, constrain_to_fx_strides)
@register_lowering(aten._scaled_mm.default, type_promotion_kind=None) # type: ignore[misc]
def tuned_scaled_mm(
mat_a,
mat_b,
scale_a,
scale_b,
bias=None,
scale_result=None,
out_dtype=None,
use_fast_accum=False,
layout=None,
):
"""
Performs an optimized matrix multiplication where scaling factors are applied
to the inputs and/or output.
Args:
mat1 (Tensor): First input matrix
mat2 (Tensor): Second input matrix
scale1 (Tensor): Scale factor applied to mat1 (supports broadcasting)
scale2 (Tensor): Scale factor applied to mat2 (supports broadcasting)
bias (Tensor, optional): Optional bias tensor to add to the result
layout: Layout hint for optimization
Returns:
Tensor: The result of the scaled matrix multiplication
"""
# TODO(coconutruben): integrate into MMKernelInputs when all callsites use that
m, n, k, layout, mat_a, mat_b = mm_args(
mat_a, mat_b, layout=layout, out_dtype=out_dtype
)
# below is for getting an overview logging info of inductor mms
counters["aten_mm_info"][f"aten._scaled_mm.default_{m}_{n}_{k}"] += 1
log.info(
"Tuned aten._scaled_mm.default: m=%s, n=%s, k=%s, mat1_dtype=%s, mat2_dtype=%s, output_layout=%s",
m,
n,
k,
mat_a.get_dtype(),
mat_b.get_dtype(),
layout,
)
check_supported_striding(mat_a, mat_b)
scale_a_real, scale_b_real = realize_inputs(scale_a, scale_b)
input_nodes: tuple[Any, ...]
if not bias:
input_nodes = (mat_a, mat_b, scale_a_real, scale_b_real)
else:
bias_real = realize_inputs(bias)
input_nodes = (mat_a, mat_b, scale_a_real, scale_b_real, bias_real)
aten_choice = aten__fp8_mm.bind(
input_nodes, layout, out_dtype=out_dtype, use_fast_accum=use_fast_accum
)
choices = []
if use_aten_gemm_kernels():
choices.append(aten_choice)
# We dont have triton lowerings for the MX variants yet
if scale_a.dtype != torch.float32:
return autotune_select_algorithm("scaled_mm", choices, input_nodes, layout)
_, is_nonzero = _is_static_problem(layout)
# Prepare triton input nodes and create kernel_inputs at the top
triton_input_nodes: list[Any]
if bias and len(mat_b.get_size()) == len(bias.get_size()) + 1:
# Need to unsqueeze bias from [N] -> [1, N]
triton_bias = L[aten.unsqueeze](bias, 0)
else:
triton_bias = bias
if len(scale_a.get_size()) == 0 or len(scale_b.get_size()) == 0:
assert len(scale_a.get_size()) == len(scale_b.get_size())
# Need to unsqueeze scale from [] -> [1, 1]
triton_scale_a = L[aten.unsqueeze](L[aten.unsqueeze](scale_a, 0), 1)
triton_scale_b = L[aten.unsqueeze](L[aten.unsqueeze](scale_b, 0), 1)
else:
triton_scale_a = scale_a
triton_scale_b = scale_b
if bias:
triton_input_nodes = [
mat_a,
mat_b,
triton_scale_a,
triton_scale_b,
triton_bias,
]
else:
triton_input_nodes = [mat_a, mat_b, triton_scale_a, triton_scale_b]
# Create MMKernelInputs for Scaled MM (matrices are at indices 0, 1)
kernel_inputs = MMKernelInputs(triton_input_nodes, mat1_idx=0, mat2_idx=1)
if is_nonzero and use_triton_template(layout, enable_float8=True):
overriders = dict(USE_FAST_ACCUM=use_fast_accum)
# TODO (paulzhan): There is no template that exists for bias and TMA
# Don't run tma template currently if bias exists
if use_triton_tma_template(mat_a, mat_b) and not bias:
# Get TMA template params using the new unified function
for kwargs, extra_kwargs in V.choices.get_mm_configs(
kernel_inputs,
layout,
scaled_mm_device_tma_template.name,
"scaled_mm",
overriders,
):
scaled_mm_device_tma_template.maybe_append_choice(
choices,
**kwargs,
**extra_kwargs,
)
# Get template params using the new unified function
for kwargs, extra_kwargs in V.choices.get_mm_configs(
kernel_inputs,
layout,
mm_template.name,
"scaled_mm",
overriders,
):
# possibly appends a TritonTemplateCaller to choices
mm_template.maybe_append_choice(
choices,
**kwargs,
**extra_kwargs,
)
if (
is_nonzero
and use_cutlass_template(layout, m, n, k)
and _use_cutlass_for_op("scaled_mm")
):
CUTLASS3xGemmTemplate.add_cutlass_gemm_choices(
choices,
layout,
kernel_inputs.nodes(), # type: ignore[arg-type]
use_fast_accum=use_fast_accum, # type: ignore[arg-type]
)
if is_nonzero and use_ck_gemm_template(layout, m, n, k):
CKGemmTemplate.add_ck_gemm_choices(choices, layout, kernel_inputs.nodes())
return autotune_select_algorithm("scaled_mm", choices, input_nodes, layout)
@functools.cache
def _is_sm7x_or_older_gpu(index: Optional[int]) -> bool:
props = torch.cuda.get_device_properties(index or 0)
return props.major <= 7
def dims_are_int(dims):
return all(isinstance(dim, int) for dim in dims)
def mm_autoheuristic(
mat1,
mat2,
m,
n,
k,
choices,
name,
input_nodes,
ops,
precondition,
top_k: Optional[int] = None,
always_included=None,
):
m, n, k = get_size_hints(mat1, mat2, m, n, k)
if not dims_are_int([m, n, k]):
return None
mat1_stride, mat2_stride = get_size_hints_strides(mat1, mat2)
def get_context(m, k, n, mat1, mat2, mat1_stride, mat2_stride):
context = AHContext()
context.add_feature("m", m)
context.add_feature("k", k)
context.add_feature("n", n)
context.add_feature("mat1_dtype", mat1.layout.dtype, is_categorical=True)
context.add_feature("mat2_dtype", mat2.layout.dtype, is_categorical=True)
context_add_strides(context, "mat1", mat1_stride)
context_add_strides(context, "mat2", mat2_stride)
context.add_feature(
"mat1_iscontig", mat1.layout.is_contiguous(), is_categorical=True
)
context.add_feature(
"mat2_iscontig", mat2.layout.is_contiguous(), is_categorical=True
)
if name == "mm":
context_add_using_tf32(context, mat1.layout.dtype)
return context
def fallback():
return None
context = get_context(m, k, n, mat1, mat2, mat1_stride, mat2_stride)
autoheuristic = AutoHeuristicSelectAlgorithm(
fallback=fallback,
choices=choices,
input_nodes=input_nodes,
context=context,
name=name,
augment_context=ops,
precondition=precondition,
)
if top_k is not None:
# TODO: is there a cleaner way to ensure aten.mm is always included?
return autoheuristic.get_top_k_choices_caller(
top_k, always_included=always_included
)
return autoheuristic.get_choice_caller()
def get_size_hints(mat1, mat2, m, n, k):
if not isinstance(m, int) or not isinstance(k, int):
(m, k) = V.graph.sizevars.size_hints(
mat1.get_size(),
fallback=torch._inductor.config.unbacked_symint_fallback,
)
if not isinstance(n, int) or not isinstance(k, int):
(k, n) = V.graph.sizevars.size_hints(
mat2.get_size(),
fallback=torch._inductor.config.unbacked_symint_fallback,
)
return m, n, k
def get_size_hints_strides(mat1, mat2):
mat1_stride = mat1.layout.stride
mat2_stride = mat2.layout.stride
strides = [mat1_stride, mat2_stride]
strides_hints = []
for stride in strides:
if not isinstance(stride, int):
stride = V.graph.sizevars.size_hints(
stride,
fallback=torch._inductor.config.unbacked_symint_fallback,
)
strides_hints.append(stride)
return strides_hints[0], strides_hints[1]