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""" Operation class for computation declaration."""
import inspect
# pylint: disable=invalid-name
from numbers import Integral as _Integral
from typing import List
import tvm._ffi
import tvm.arith._ffi_api
import tvm.tir
import tvm.tir._ffi_api
from tvm._ffi.base import string_types
from tvm.ir import Array
from tvm.runtime import convert
from . import _ffi_api
from . import tag as _tag
from . import tensor as _tensor
def placeholder(shape, dtype=None, name="placeholder"):
"""Construct an empty tensor object.
Parameters
----------
shape: Tuple of Expr
The shape of the tensor
dtype: str, optional
The data type of the tensor
name: str, optional
The name hint of the tensor
Returns
-------
tensor: Tensor
The created tensor
"""
shape = (shape,) if isinstance(shape, tvm.tir.PrimExpr) else shape
dtype = "float32" if dtype is None else dtype
return _ffi_api.Placeholder(shape, dtype, name)
def compute(shape, fcompute, name="compute", tag="", attrs=None, varargs_names=None):
"""Construct a new tensor by computing over the shape domain.
The compute rule is result[axis] = fcompute(axis)
Parameters
----------
shape: Tuple of Expr
The shape of the tensor
fcompute: lambda function of indices-> value
Specifies the input source expression
name: str, optional
The name hint of the tensor
tag: str, optional
Additional tag information about the compute.
attrs: dict, optional
The additional auxiliary attributes about the compute.
varargs_names: list, optional
The names to use for each of the varargs. If not supplied, the varargs
will be called i1, i2, ...
Returns
-------
tensor: Tensor
The created tensor
"""
if _tag.TagScope.get_current() is not None:
if tag != "":
raise ValueError("nested tag is not allowed for now")
tag = _tag.TagScope.get_current().tag
shape = (shape,) if isinstance(shape, tvm.tir.PrimExpr) else shape
# for python3
shape = tuple([int(s) if isinstance(s, float) else s for s in shape])
out_ndim = len(shape)
argspec = inspect.getfullargspec(fcompute)
if len(argspec.args) == 0 and argspec.varargs is None:
arg_names = ["i%d" % i for i in range(out_ndim)]
elif argspec.varargs is not None:
# if there is a varargs, it takes the remaining dimensions of out_ndim
num_remaining_args = out_ndim - len(argspec.args)
if varargs_names is not None:
if len(varargs_names) != num_remaining_args:
raise RuntimeError(
f"Number of varargs ({num_remaining_args}) does not match number"
f"of varargs_names ({len(varargs_names)})"
)
arg_names = argspec.args + varargs_names
else:
arg_names = argspec.args + [f"i{i}" for i in range(out_ndim - len(argspec.args))]
else:
arg_names = argspec.args
# if there are fewer args than out dimensions, the remaining dimensions
# are implicitly broadcast
out_ndim = len(arg_names)
assert argspec.varkw is None, "Variable keyword arguments not supported in fcompute"
assert argspec.defaults is None, "Default arguments not supported in fcompute"
assert len(argspec.kwonlyargs) == 0, "Keyword arguments are not supported in fcompute"
if out_ndim != len(arg_names):
raise ValueError(
"Number of args to fcompute does not match dimension, "
"args=%d, dimension=%d" % (len(arg_names), out_ndim)
)
dim_var = [tvm.tir.IterVar((0, s), x, 0) for x, s in zip(arg_names, shape[:out_ndim])]
body = fcompute(*[v.var for v in dim_var])
if isinstance(body, _tensor.TensorIntrinCall):
for i, s in enumerate(shape[out_ndim:]):
var_name = "ax" + str(i)
dim_var.append(tvm.tir.IterVar((0, s), var_name, 4))
op_node = _ffi_api.TensorComputeOp(
name,
tag,
dim_var,
body.reduce_axis,
out_ndim,
body.intrin,
body.tensors,
body.regions,
body.scalar_inputs,
)
else:
if not isinstance(body, (list, tuple)):
body = [body]
body = convert(body)
op_node = _ffi_api.ComputeOp(name, tag, attrs, dim_var, body)
num = op_node.num_outputs
outputs = tuple(op_node.output(i) for i in range(num))
return outputs[0] if num == 1 else outputs
def scan(init, update, state_placeholder, inputs=None, name="scan", tag="", attrs=None):
"""Construct new tensors by scanning over axis.
Parameters
----------
init: Tensor or list of Tensor
The initial condition of first init.shape[0] timestamps
update: Tensor or list of Tensor
The update rule of the scan given by symbolic tensor.
state_placeholder: Tensor or list of Tensor
The placeholder variables used by update.
inputs: Tensor or list of Tensor, optional
The list of inputs to the scan. This is not required, but can
be useful for the compiler to detect scan body faster.
name: str, optional
The name hint of the tensor
tag: str, optional
Additonal tag information about the compute.
attrs: dict, optional
The additional auxiliary attributes about the compute.
Returns
-------
tensor: Tensor or list of Tensors
The created tensor or tuple of tensors contains multiple outputs.
Example
-------
.. code-block:: python
# The following code is equivalent to numpy.cumsum
m = te.var("m")
n = te.var("n")
X = te.placeholder((m, n), name="X")
s_state = te.placeholder((m, n))
s_init = te.compute((1, n), lambda _, i: X[0, i])
s_update = te.compute((m, n), lambda t, i: s_state[t-1, i] + X[t, i])
res = tvm.te.scan(s_init, s_update, s_state, X)
"""
if _tag.TagScope.get_current() is not None:
if tag != "":
raise ValueError("nested tag is not allowed for now")
tag = _tag.TagScope.get_current().tag
if isinstance(init, _tensor.Tensor):
init = [init]
if isinstance(update, _tensor.Tensor):
update = [update]
if isinstance(state_placeholder, _tensor.Tensor):
state_placeholder = [state_placeholder]
if isinstance(inputs, _tensor.Tensor):
inputs = [inputs]
if inputs is None:
inputs = []
if len(init) != len(update) or len(init) != len(state_placeholder):
raise ValueError("init, update, state_placeholder must have same length")
axis = tvm.tir.IterVar((init[0].shape[0], update[0].shape[0]), "%s.idx" % name, 3)
op = _ffi_api.ScanOp(name, tag, attrs, axis, init, update, state_placeholder, inputs)
res = [op.output(i) for i in range(len(update))]
return res[0] if len(res) == 1 else res
def extern(
shape,
inputs,
fcompute,
name="extern",
dtype=None,
in_buffers=None,
out_buffers=None,
tag="",
attrs=None,
):
"""Compute several tensors via an extern function.
Parameters
----------
shape: tuple or list of tuples.
The shape of the outputs.
inputs: list of Tensor
The inputs
fcompute: lambda function of inputs, outputs-> stmt
Specifies the IR statement to do the computation.
See the following note for function signature of fcompute
.. note::
**Parameters**
- **ins** (list of :any:`tvm.tir.Buffer`) - Placeholder for each inputs
- **outs** (list of :any:`tvm.tir.Buffer`) - Placeholder for each outputs
**Returns**
- **stmt** (:any:`tvm.tir.Stmt`) - The statement that carries out array computation.
name: str, optional
The name hint of the tensor
dtype: str or list of str, optional
The data types of outputs,
by default dtype will be same as inputs.
in_buffers: tvm.tir.Buffer or list of tvm.tir.Buffer, optional
Input buffers.
out_buffers: tvm.tir.Buffer or list of tvm.tir.Buffer, optional
Output buffers.
tag: str, optional
Additonal tag information about the compute.
attrs: dict, optional
The additional auxiliary attributes about the compute.
Returns
-------
tensor: Tensor or list of Tensors
The created tensor or tuple of tensors contains multiple outputs.
Example
-------
In the code below, C is generated by calling external PackedFunc
`tvm.contrib.cblas.matmul`
.. code-block:: python
A = te.placeholder((n, l), name="A")
B = te.placeholder((l, m), name="B")
C = te.extern((n, m), [A, B],
lambda ins, outs: tvm.tir.call_packed(
"tvm.contrib.cblas.matmul",
ins[0], ins[1], outs[0], 0, 0), name="C")
"""
if _tag.TagScope.get_current() is not None:
if tag != "":
raise ValueError("nested tag is not allowed for now")
tag = _tag.TagScope.get_current().tag
shape = (shape,) if isinstance(shape, (tvm.tir.PrimExpr, _Integral)) else shape
if shape == () or isinstance(shape[0], (tvm.tir.PrimExpr, _Integral)):
shape = [shape]
if in_buffers is not None:
in_buffers = [in_buffers] if not isinstance(in_buffers, list) else in_buffers
if len(inputs) != len(in_buffers):
raise RuntimeError(
"Number of inputs and in_buffers mismatch: %d vs %d."
% (len(inputs), len(in_buffers))
)
if out_buffers is not None:
out_buffers = [out_buffers] if not isinstance(out_buffers, list) else out_buffers
if len(shape) != len(out_buffers):
raise RuntimeError(
"Number of outputs and out_buffers mismatch: %d vs %d."
% (len(shape), len(out_buffers))
)
input_placeholders = in_buffers or []
output_placeholders = out_buffers or []
types = set()
for t in inputs:
if not isinstance(t, _tensor.Tensor):
raise ValueError("expect inputs to be tensor")
if in_buffers is None:
input_placeholders.append(tvm.tir.decl_buffer(t.shape, t.dtype, t.op.name))
types.add(t.dtype)
if dtype is None:
if len(types) != 1:
raise ValueError("Cannot infer output type, please provide dtype argument")
infered_type = types.pop()
dtype = [infered_type for _ in shape]
if isinstance(dtype, str):
dtype = [dtype]
if out_buffers is None:
for shp, dt in zip(shape, dtype):
output_placeholders.append(tvm.tir.decl_buffer(shp, dt, name))
body = fcompute(input_placeholders, output_placeholders)
if isinstance(body, tvm.tir.PrimExpr):
body = tvm.tir.Evaluate(body)
if not isinstance(body, tvm.tir.Stmt):
raise ValueError(
"Function '{}' should return PrimExpr or Stmt, but it returned '{}'".format(
fcompute.__name__, type(body)
)
)
op = _ffi_api.ExternOp(name, tag, attrs, inputs, input_placeholders, output_placeholders, body)
res = [op.output(i) for i in range(len(output_placeholders))]
return res[0] if len(res) == 1 else res
def extern_primfunc(input_tensors: List[_tensor.Tensor], primfunc: tvm.tir.PrimFunc, **kwargs):
"""Compute tensors via a schedulable TIR PrimFunc
Parameters
----------
input_tensors: list of Tensor
Input tensors that map to the corresponding primfunc input params.
primfunc: PrimFunc
The TIR PrimFunc
Returns
-------
tensor: Tensor or list of Tensors
The created tensor or tuple of tensors if it contains multiple outputs.
Example
-------
In the code below, a TVMScript defined TIR PrimFunc is inlined into
a TE ExternOp. Applying te.create_prim_func on this
.. code-block:: python
A = te.placeholder((128, 128), name="A")
B = te.placeholder((128, 128), name="B")
@T.prim_func
def before_split(a: T.handle, b: T.handle) -> None:
A = T.match_buffer(a, (128, 128))
B = T.match_buffer(b, (128, 128))
for i, j in T.grid(128, 128):
with T.block("B"):
vi, vj = T.axis.remap("SS", [i, j])
B[vi, vj] = A[vi, vj] * 2.0
C = te.extern_primfunc([A, B], func)
"""
access_map = {
k: tuple(v) for k, v in tvm.arith._ffi_api.DomainTouchedAccessMap(primfunc).items()
}
in_buffers = [buf for buf, access in access_map.items() if len(access[0])]
out_buffers = [buf for buf, access in access_map.items() if len(access[1])]
assert in_buffers, "PrimFunc has no input buffers"
assert out_buffers, "PrimFunc has no output buffers"
outputs = []
inplace = []
input_buffers = in_buffers
for obuf in out_buffers:
if obuf in in_buffers:
inplace.append(obuf)
else:
outputs.append(obuf)
if not outputs:
iobuf = inplace.pop()
input_buffers.remove(iobuf)
outputs = [iobuf]
assert len(input_buffers) == len(input_tensors), (
"The number of provided input input_tensors does not match the number of ",
"input buffers in the primfunc",
)
for tensor, buffer in zip(input_tensors, input_buffers):
# TODO(csullivan): Can a stronger comparison between Tensor<>Buffer be made?
assert len(tensor.shape) == len(buffer.shape)
for d1, d2 in zip(tensor.shape, buffer.shape):
assert d1 == d2, (
"The input input_tensors provided do not match the input buffers in the ",
"primfunc. Please check that the order of input te.Input_Tensors and the ",
"order of the primfunc variables in the params list agree.",
)
output = extern(
[buf.shape for buf in outputs],
input_tensors,
lambda ins, outs: primfunc.body,
in_buffers=input_buffers,
out_buffers=outputs,
**kwargs,
)
return output
def var(name="tindex", dtype="int32", span=None):
"""Create a new variable with specified name and dtype
Parameters
----------
name : str
The name
dtype : str
The data type
span : Optional[Span]
The location of this variable in the source.
Returns
-------
var : Var
The result symbolic variable.
"""
return tvm.tir.Var(name, dtype, span)
def const(dtype="int32", span=None):
"""Create a new constant with specified name and dtype
Parameters
----------
name : str
The name
dtype : str
The data type
span : Optional[Span]
The location of this variable in the source.
Returns
-------
var : Var
The result symbolic variable.
"""
return tvm.tir.const(dtype, span)
def size_var(name="size", dtype="int32", span=None):
"""Create a new variable represents a tensor shape size, which is non-negative.
Parameters
----------
name : str
The name
dtype : str
The data type
span : Optional[Span]
The location of this variable in the source.
Returns
-------
var : SizeVar
The result symbolic shape variable.
"""
return tvm.tir.SizeVar(name, dtype, span)
def thread_axis(dom=None, tag="", name="", span=None):
"""Create a new IterVar to represent thread index.
Parameters
----------
dom : Range or str
The domain of iteration
When str is passed, dom is set to None and str is used as tag
tag : str, optional
The thread tag
name : str, optional
The name of the var.
span : Optional[Span]
The location of this variable in the source.
Returns
-------
axis : IterVar
The thread itervar.
"""
if isinstance(dom, string_types):
tag, dom = dom, None
if not tag:
raise ValueError("tag must be given as Positional or keyword argument")
name = name if name else tag
return tvm.tir.IterVar(dom, name, 1, tag, span)
def reduce_axis(dom, name="rv", thread_tag="", span=None):
"""Create a new IterVar for reduction.
Parameters
----------
dom : Range
The domain of iteration.
name : str
The name of the variable.
thread_tag : Optional[str]
The name of the thread_tag.
span : Optional[Span]
The location of this variable in the source.
Returns
-------
axis : IterVar
An iteration variable representing the value.
"""
return tvm.tir.IterVar(dom, name, 2, thread_tag, span)
def create_prim_func(ops: List[_tensor.Tensor]) -> tvm.tir.PrimFunc:
"""Create a TensorIR PrimFunc from tensor expression
Parameters
----------
ops : List[Tensor]
The source expression.
Example
-------
We define a matmul kernel using following code:
.. code-block:: python
import tvm
from tvm import te
from tvm.te import create_prim_func
import tvm.script
A = te.placeholder((128, 128), name="A")
B = te.placeholder((128, 128), name="B")
k = te.reduce_axis((0, 128), "k")
C = te.compute((128, 128), lambda x, y: te.sum(A[x, k] * B[y, k], axis=k), name="C")
func = create_prim_func([A, B, C])
print(func.script())
If we want to use TensorIR schedule to do transformations on such kernel,
we need to use `create_prim_func([A, B, C])` to create a schedulable PrimFunc.
The generated function looks like:
.. code-block:: python
@T.prim_func
def tir_matmul(a: T.handle, b: T.handle, c: T.handle) -> None:
A = T.match_buffer(a, (128, 128))
B = T.match_buffer(b, (128, 128))
C = T.match_buffer(c, (128, 128))
for i, j, k in T.grip(128, 128, 128):
with T.block():
vi, vj, vk = T.axis.remap("SSR", [i, j, k])
with T.init():
C[vi, vj] = 0.0
C[vi, vj] += A[vi, vk] * B[vj, vk]
Returns
-------
func : tir.PrimFunc
The created function.
"""
if not isinstance(ops, (list, tuple, Array)):
ops = [ops]
return _ffi_api.CreatePrimFunc(ops)