# Copyright (c) Meta Platforms, Inc. and affiliates.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
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#
"""
Softmax op implementation
"""
import logging
import os
import re
from collections import OrderedDict
from hashlib import sha1
from operator import itemgetter
from typing import Dict, List, Union
import jinja2
from aitemplate import backend
from aitemplate.backend import registry
from aitemplate.backend.target import Target
from aitemplate.compiler.base import (
DynamicProfileStrategy,
ExecItem,
IntImm,
IntVar,
Operator,
Tensor,
)
from aitemplate.compiler.ops.softmax.cache_entry import NormQueryEntry, NormRecordEntry
from aitemplate.testing import detect_target
from aitemplate.utils.tensor_utils import wrap_dim
_LOGGER = logging.getLogger(__name__)
EXEC_COND_TEMPLATE = jinja2.Template(
"""
{{indent}}if ({{cond}}) {
{{indent}} {{program}}
{{indent}}}
"""
)
[docs]class softmax(Operator):
r"""Applies the Softmax function to a 2D input Tensor
rescaling them so that the elements of the n-dimensional output Tensor
lie in the range [0,1] and sum to 1.
Softmax is defined as:
.. math::
\text{Softmax}(x_{i}) = \frac{\exp(x_i)}{\sum_j \exp(x_j)}
Args:
input (Tensor [N, M]):
dim (int): optional, a dimension along which Softmax will be computed (so every slice
along dim will sum to 1). Default: None, in this case the input tensor will be treated as
a 1-D tensor.
Returns:
Tensor: a Tensor of the same dimension and shape as the input with
values in the range [0, 1].
"""
def __init__(
self,
) -> None:
"""initialize the op"""
super().__init__()
self._attrs["op"] = "softmax"
self._attrs["has_profiler"] = False
if detect_target().name() == "rocm":
self._attrs["has_profiler"] = True
def _infer_shapes(self, x: Tensor) -> List[IntVar]:
"""Infer output shape for the softmax op.
Parameters
----------
x : Tensor
Input shape of softmax op.
Returns
----------
List[IntVar]
"""
shapes = x._attrs["shape"]
assert (
len(shapes) >= 2
), f"softmax only supports input with rank >= 2, current rank: {len(shapes)}"
return x._attrs["shape"]
def _invert_exec_key(self, key: str):
"""Invert execution key to get input arguments as integers.
Parameters
----------
key : str
Execution key
Returns
----------
List[int]
"""
res = []
for item in re.split(" == | && ", key):
if item.isnumeric():
res.append(int(item))
return res
def _gen_exec_key(self, name_value_mapping: Dict[str, Union[int, List[int]]]):
"""Generate execution key from the name value mapping.
Parameters
----------
name_value_mapping : Dict[str, Union[int, List[int]]
Dict for name and value.
Returns
----------
str
"""
key_strs = []
for name, values in name_value_mapping.items():
if len(values) == 1:
key_strs.append(f"{name} == {values[0]}")
elif len(values) > 1:
key_strs.append(f"{name} >= {values[0]} && {name} <= {values[-1]}")
else:
raise RuntimeError(
"Softmax input has empty dim values: {}".format(values)
)
return " && ".join(key_strs)
def _extract_exec_path(self, dynamic_profiling_strategy=DynamicProfileStrategy.MAX):
"""Extract execution key, i.e. input arguments for the profiler.
Parameters
----------
dynamic_profiling_strategy: DynamicProfileStrategy, optional
A dynamic profiling strategy. By default MAX is used, i.e. to profile
a dynamic range, an upper bound will be used.
"""
shape_values_dict = {
var._attrs["name"]: var._attrs["values"]
for var in self._attrs["inputs"][0]._attrs["shape"]
}
self._attrs["exec_path"] = OrderedDict()
if dynamic_profiling_strategy == DynamicProfileStrategy.MAX:
max_values = {
name: [max(shape_values)]
for name, shape_values in shape_values_dict.items()
}
exec_item = ExecItem(
profiling_key=self._gen_exec_key(max_values),
exec_cond=self._gen_exec_key(shape_values_dict),
algo="",
)
self._attrs["exec_path"][exec_item.profiling_key] = exec_item
elif dynamic_profiling_strategy == DynamicProfileStrategy.MIN:
min_values = {
name: [min(shape_values)]
for name, shape_values in shape_values_dict.items()
}
exec_item = ExecItem(
profiling_key=self._gen_exec_key(min_values),
exec_cond=self._gen_exec_key(shape_values_dict),
algo="",
)
self._attrs["exec_path"][exec_item.profiling_key] = exec_item
def __call__(self, x: Tensor, dim: int = None) -> Tensor:
"""call the op
Parameters
----------
x : Tensor
input tensor
dim : int
the dimension to be normalized.
(default: None, in this case the input tensor will be treated as
a 1-D tensor)
Returns
----------
Tensor
"""
if dim is None:
raise NotImplementedError(
"flattening input tensor before normalization is not supported yet"
)
dim = wrap_dim(dim, x._rank())
inner_dims = x.shape()[dim + 1 :]
if not all(isinstance(d, IntImm) for d in inner_dims):
raise NotImplementedError(
"inner dims must all be static; {dim=}, {x.shape()=}"
)
self._attrs["inputs"] = [x]
self._attrs["dim"] = dim
self._set_depth()
output_shape = self._infer_shapes(x)
output = Tensor(output_shape, src_ops={self}, dtype=x.dtype())
self._attrs["outputs"] = [output]
return output
def _gen_profile_cmd(self, profiler_prefix, cfg, x_shape):
"""Generate profiler command.
Parameters
----------
profiler_prefix : str
Directory to store profiler.
cfg: str
The filename generated for profiler.
x_shape : List[int]
Input shapes for the profiler.
"""
exe_path = os.path.join(profiler_prefix, cfg)
if not os.access(exe_path, os.X_OK):
raise RuntimeError("Profiler %s is not executable" % exe_path)
cmd = [exe_path]
for shape in x_shape:
cmd.append(shape)
command = [str(x) for x in cmd]
return command
def _profile_single_workload(self, profiler_prefix, exec_key, devices):
"""Profile a single workload.
Parameters
----------
profiler_prefix : str
Base dir to keep profiling source codes.
exec_key: str
Input arguments to profiler executables.
devices: List[int]
GPU device ids used for profiling.
"""
target = backend.target.Target.current()
# if in CI just choose minimal configs
# workspace is a hack just provides 102400 Byte
# query cache
tmp_key = next(iter(self._attrs["op_instance"].keys()))
tmp_op = self._attrs["op_instance"][tmp_key]
exec_entry_sha1 = sha1(exec_key.encode("utf-8")).hexdigest()
query = NormQueryEntry(
dtype_in=tmp_op.In.value,
dtype_acc=tmp_op.accumulator_type().value,
dtype_out=tmp_op.Out.value,
rank=tmp_op.Rank,
op_type=self._attrs["op"],
device=target._arch,
exec_entry_sha1=exec_entry_sha1,
)
cache_value = target.query_profile_cache("normalization", query.__dict__)
if cache_value is not None and not target.force_profile():
_LOGGER.info("Load profiling result from cache.")
return cache_value
content = list(self._attrs["op_instance"].keys())
runner = backend.profiler_runner.Runner(devices, self._attrs["name"])
x_shape = self._invert_exec_key(exec_key)
for cfg in content:
command = self._gen_profile_cmd(profiler_prefix, cfg, x_shape)
runner.push(cfg, command)
runner.join()
result = runner.pull()
if len(result) == 0:
raise RuntimeError(
"Profile workload: " f"{exec_key}" " failed. " f"Results: {result}."
)
out = min(result, key=itemgetter(1))
best_algo = out[0]
workspace = out[1].workspace
## cache
cache_record = NormRecordEntry(
exec_entry=exec_key,
exec_entry_sha1=exec_entry_sha1,
dtype_in=tmp_op.In.value,
dtype_acc=tmp_op.accumulator_type().value,
dtype_out=tmp_op.Out.value,
rank=tmp_op.Rank,
op_type=self._attrs["op"],
device=target._arch,
algo=best_algo,
workspace=workspace,
)
Target.current().insert_profile_cache("normalization", cache_record.__dict__)
return (best_algo, workspace)
[docs] def profile(
self,
workdir="./",
devices=None,
dynamic_profiling_strategy=DynamicProfileStrategy.MAX,
):
"""Selects the fastest kernel configurations.
Parameters
----------
workdir : str, optional
Base dir to keep profiling source codes, by default "./"
devices: list, optional
Devices used for profiling, by default device 0 will be used.
dynamic_profiling_strategy: DynamicProfileStrategy, optional
A dynamic profiling strategy. By default MAX is used, i.e. to profile
a dynamic range, an upper bound will be used.
"""
if devices is None:
devices = [0]
self._extract_exec_path(dynamic_profiling_strategy)
workloads = list(self._attrs["exec_path"].keys())
profiler_prefix = os.path.join(workdir, "profiler", self._attrs["op"])
if "op_instance" not in self._attrs:
target = backend.target.Target.current()
# init candidate ops
func_key = "{target}.{op}.config".format(
target=target.name(), op=self._attrs["op"]
)
func = registry.get(func_key)
func(self._attrs)
for wkl in workloads:
_LOGGER.info(
"Profile: {name}: {wkl}".format(name=self._attrs["name"], wkl=wkl),
)
best_algo, workspace = self._profile_single_workload(
profiler_prefix, wkl, devices
)
self._attrs["exec_path"][wkl].algo = best_algo
self._attrs["workspace"] = workspace
[docs] def gen_profiler(
self,
workdir: str = None,
dynamic_profiling_strategy=DynamicProfileStrategy.HINTS,
) -> None:
"""Generator profiler. The profiler files are standalone executable for profiling.
Parameters
----------
workdir : str, optional
Base dir to keep profiling source codes, by default "./"
dynamic_profiling_strategy: DynamicProfileStrategy, optional
A dynamic profiling strategy, used to filter generated profiles at compile time.
See also: :func:`~aitemplate.compiler.transform.profile.profile`
"""
target = Target.current()
# init candidate ops
func_key = "{target}.{op}.config".format(
target=target.name(), op=self._attrs["op"]
)
func = registry.get(func_key)
func(self._attrs)
func_key = "{target}.{op}.gen_profiler".format(
target=target.name(), op=self._attrs["op"]
)
func = registry.get(func_key)
func(self._attrs, workdir)
[docs] def gen_function(self) -> str:
"""Generate function body.
Returns
-------
str
The rendered template of generated function body.
"""
target = backend.target.Target.current()
func_key = "{target}.{op}.gen_function".format(
target=target.name(), op=self._attrs["op"]
)
self._attrs["exec_cond_template"] = EXEC_COND_TEMPLATE
func = registry.get(func_key)
return func(self._attrs)
def _args_for_pseudo_code(self):
return {"dim": self._attrs["dim"]}