onnxruntime-tvm/python/tvm/api.py

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Python

"""Functions defined in TVM."""
# pylint: disable=invalid-name,unused-import,redefined-builtin
from __future__ import absolute_import as _abs
from numbers import Integral as _Integral
from ._ffi.base import string_types
from ._ffi.node import register_node, NodeBase
from ._ffi.node import convert_to_node as _convert_to_node
from ._ffi.function import Function
from ._ffi.function import _init_api, register_func, get_global_func, extract_ext_funcs
from ._ffi.function import convert_to_tvm_func as _convert_tvm_func
from ._ffi.runtime_ctypes import TVMType
from . import _api_internal
from . import make as _make
from . import expr as _expr
from . import tensor as _tensor
from . import schedule as _schedule
from . import container as _container
from . import tag as _tag
int8 = "int8"
int32 = "int32"
float32 = "float32"
handle = "handle"
def min_value(dtype):
"""minimum value of dtype
Parameters
----------
dtype : str
The data type.
Returns
-------
value : tvm.Expr
The minimum value of dtype.
"""
return _api_internal._min_value(dtype)
def max_value(dtype):
"""maximum value of dtype
Parameters
----------
dtype : str
The data type.
Returns
-------
value : tvm.Expr
The maximum value of dtype.
"""
return _api_internal._max_value(dtype)
def const(value, dtype):
"""construct a constant
Parameters
----------
value : number
The content of the constant number.
dtype : str
The data type.
Returns
-------
const_val: tvm.Expr
The result expression.
"""
return _api_internal._const(value, dtype)
def get_env_func(name):
"""Get an EnvFunc by a global name.
Parameters
----------
name: str
The name of the global function.
Returns
-------
env_func : EnvFunc
The result env function.
Note
----
EnvFunc is a Node wrapper around
global function that can be serialized via its name.
This can be used to serialize function field in the language.
"""
return _api_internal._EnvFuncGet(name)
def convert(value):
"""Convert value to TVM node or function.
Parameters
----------
value : python value
Returns
-------
tvm_val : Node or Function
Converted value in TVM
"""
if isinstance(value, (Function, NodeBase)):
return value
if callable(value):
return _convert_tvm_func(value)
return _convert_to_node(value)
def load_json(json_str):
"""Load tvm object from json_str.
Parameters
----------
json_str : str
The json string
Returns
-------
node : Node
The loaded tvm node.
"""
return _api_internal._load_json(json_str)
def save_json(node):
"""Load tvm object as json string.
Parameters
----------
node : Node
A TVM Node object to be saved.
Returns
-------
json_str : str
Saved json string.
"""
return _api_internal._save_json(node)
def var(name="tindex", dtype=int32):
"""Create a new variable with specified name and dtype
Parameters
----------
name : str
The name
dtype : int
The data type
Returns
-------
var : Var
The result symbolic variable.
"""
return _api_internal._Var(name, dtype)
def any(*args):
"""Create a new experssion of the union of all conditions in the arguments
Parameters
----------
args : list
List of symbolic boolean expressions
Returns
-------
expr: Expr
Expression
"""
if not args:
raise ValueError("Any must take at least 1 argument")
if len(args) == 1:
return args[0]
ret = _make._OpOr(args[0], args[1])
for i in range(2, len(args)):
ret = _make._OpOr(ret, args[i])
return ret
def all(*args):
"""Create a new experssion of the intersection of all conditions in the
arguments
Parameters
----------
args : list
List of symbolic boolean expressions
Returns
-------
expr: Expr
Expression
"""
if not args:
raise ValueError("Any must take at least 1 argument")
if len(args) == 1:
return args[0]
ret = _make._OpAnd(args[0], args[1])
for i in range(2, len(args)):
ret = _make._OpAnd(ret, args[i])
return ret
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, _expr.Expr) else shape
dtype = float32 if dtype is None else dtype
return _api_internal._Placeholder(
shape, dtype, name)
def compute(shape, fcompute, name="compute", tag="", attrs=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
Additonal tag information about the compute.
attrs: dict, optional
The additional auxiliary attributes about the compute.
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, _expr.Expr) else shape
# for python3
shape = tuple([int(s) if isinstance(s, float) else s for s in shape])
ndim = len(shape)
code = fcompute.__code__
out_ndim = ndim
if code.co_argcount == 0:
arg_names = ["i%d" % i for i in range(ndim)]
else:
arg_names = code.co_varnames[:code.co_argcount]
out_ndim = code.co_argcount
if out_ndim != len(arg_names):
raise ValueError("fcompute do not match dimension, ndim=%d" % ndim)
dim_var = [_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(_IterVar((0, s), var_name, 4))
op_node = _api_internal._TensorComputeOp(name,
tag,
dim_var,
body.reduce_axis,
out_ndim,
body.intrin,
body.tensors,
body.regions)
else:
if not isinstance(body, (list, tuple)):
body = [body]
body = convert(body)
op_node = _api_internal._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 it it contains multiple outputs.
Example
-------
.. code-block:: python
# The following code is equivalent to numpy.cumsum
m = tvm.var("m")
n = tvm.var("n")
X = tvm.placeholder((m, n), name="X")
s_state = tvm.placeholder((m, n))
s_init = tvm.compute((1, n), lambda _, i: X[0, i])
s_update = tvm.compute((m, n), lambda t, i: s_state[t-1, i] + X[t, i])
res = tvm.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 = _IterVar((init[0].shape[0], update[0].shape[0]), "%s.idx" % name, 3)
op = _api_internal._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 tensor via 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:`Buffer`) - Placeholder for each inputs
- **outs** (list of :any:`Buffer`) - Placeholder for each outputs
**Returns**
- **stmt** (:any:`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: Buffer or list of Buffer, optional
Input buffers.
out_buffers: Buffer or list of Buffers, 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 it it contains multiple outputs.
Example
-------
In the code below, C is generated by calling external PackedFunc
`tvm.contrib.cblas.matmul`
.. code-block:: python
A = tvm.placeholder((n, l), name='A')
B = tvm.placeholder((l, m), name='B')
C = tvm.extern((n, m), [A, B],
lambda ins, outs: tvm.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, (_expr.Expr, _Integral)) else shape
shape = [shape] if isinstance(shape[0], (_expr.Expr, _Integral)) else 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(
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(decl_buffer(shp, dt, name))
body = fcompute(input_placeholders, output_placeholders)
if isinstance(body, _expr.Expr):
body = _make.Evaluate(body)
op = _api_internal._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 decl_buffer(shape,
dtype=None,
name="buffer",
data=None,
strides=None,
elem_offset=None,
scope="",
data_alignment=-1,
offset_factor=0):
"""Decleare a new symbolic buffer.
Normally buffer is created automatically during lower and build.
This is only needed if user want to specify their own buffer layout.
See the note below for detailed discussion on usage of buffer.
Parameters
----------
shape : tuple of Expr
The shape of the buffer.
dtype : str, optional
The data type of the buffer.
name : str, optional
The name of the buffer.
data : Var, optional
The data pointer in the buffer.
strides: array of Expr
The stride of the buffer.
elem_offset: Expr, optional
The beginning offset of the array to data.
In terms of number of elements of dtype.
scope: str, optional
The storage scope of the buffer, if not global.
If scope equals empty string, it means it is global memory.
data_alignment: int, optional
The alignment of data pointer in bytes.
If -1 is passed, the alignment will be set to TVM's internal default.
offset_factor: int, optional
The factor of elem_offset field, when set,
elem_offset is required to be multiple of offset_factor.
If 0 is pssed, the alignment will be set to 1.
if non-zero is passed, we will created a Var for elem_offset if elem_offset is not None.
Returns
-------
buffer : Buffer
The created buffer
Note
----
Buffer data structure reflects the DLTensor structure in dlpack.
While DLTensor data structure is very general, it is usually helpful
to create function that only handles specific case of data structure
and make compiled function benefit from it.
If user pass strides and elem_offset is passed as None
when constructing the function, then the function will be specialized
for the DLTensor that is compact and aligned.
If user pass a fully generic symbolic array to the strides,
then the resulting function becomes fully generic.
"""
shape = (shape,) if isinstance(shape, (_expr.Expr, _Integral)) else shape
dtype = float32 if dtype is None else dtype
strides = () if strides is None else strides
if offset_factor != 0 and elem_offset is None:
shape_dtype = shape[0].dtype if hasattr(shape[0], "dtype") else "int32"
elem_offset = var('%s_elem_offset' % name, shape_dtype)
if data is None:
data = var(name, "handle")
return _api_internal._Buffer(
data, dtype, shape, strides, elem_offset, name, scope,
data_alignment, offset_factor)
def _IterVar(dom, name, iter_type, thread_tag=''):
"""Internal function to create IterVar
Parameters
----------
dom : Range
The domain of iteration.
name : str
The name of iteration variable.
iter_type : int
The type of iteration.
thread_tag : str
The thread tag of the iteration variable.
Returns
-------
iter_var : IterVar
The result itervar
"""
if dom is not None:
if isinstance(dom, (list, tuple)):
if len(dom) != 2:
raise TypeError("need to be list of ranges")
dom = Range(dom[0], dom[1])
if not isinstance(dom, _container.Range):
raise TypeError("dom need to be Range")
name = name if name else 'iter'
v = var(name)
return _api_internal._IterVar(dom, v, iter_type, thread_tag)
def thread_axis(dom=None, tag='', name=''):
"""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.
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 _IterVar(dom, name, 1, tag)
def reduce_axis(dom, name="rv"):
"""Create a new IterVar for reduction.
Parameters
----------
dom : Range
The domain of iteration.
name : str
The name of the variable.
Returns
-------
axis : IterVar
An iteration variable representing the value.
"""
return _IterVar(dom, name, 2)
def comm_reducer(fcombine, fidentity, name="reduce"):
"""Create a commutative reducer for reduction.
Parameters
----------
fcombine : function(Expr -> Expr -> Expr)
A binary function which takes two Expr as input to return a Expr.
fidentity : function(str -> Expr)
A function which takes a type string as input to return a const Expr.
Returns
-------
reducer : function
A function which creates a reduce expression over axis.
There are two ways to use it:
1. accept (expr, axis, where) to produce an Reduce Expr on
specified axis;
2. simply use it with multiple Exprs.
Example
-------
.. code-block:: python
n = tvm.var('n')
m = tvm.var('m')
mysum = tvm.comm_reducer(lambda x, y: x+y,
lambda t: tvm.const(0, dtype=t), name="mysum")
A = tvm.placeholder((n, m), name='A')
k = tvm.reduce_axis((0, m), name='k')
B = tvm.compute((n,), lambda i: mysum(A[i, k], axis=k), name='B')
"""
def _reduce_directly(*args):
num = len(args)
# process `where` is None
if num == 3 and args[2] is None:
num = 2
res = args[0]
for i in range(num-1):
res = fcombine(res, args[i+1])
return res
def _make_reduce(expr, axis, where=None):
code = fcombine.__code__
assert fcombine.__code__.co_argcount == 2
expr = convert(expr)
if isinstance(expr, _container.Array):
size = len(expr)
larr = []
rarr = []
dtypes = []
for i in range(size):
dtype = expr[i].dtype
dtypes.append(dtype)
lname = code.co_varnames[0] + '_' + str(i)
larr.append(var(lname, dtype))
rname = code.co_varnames[1] + '_' + str(i)
rarr.append(var(rname, dtype))
lhs = convert(larr)
rhs = convert(rarr)
result = fcombine(lhs, rhs)
id_elem = fidentity(*dtypes)
else:
assert isinstance(expr, _expr.Expr)
size = 1
dtype = expr.dtype
lvar = var(code.co_varnames[0], dtype)
rvar = var(code.co_varnames[1], dtype)
result = [fcombine(lvar, rvar)]
id_elem = [fidentity(dtype)]
lhs = convert([lvar])
rhs = convert([rvar])
expr = convert([expr])
result = convert(result)
id_elem = convert(id_elem)
combiner = _make.CommReducer(lhs, rhs, result, id_elem)
axis = convert(axis if isinstance(axis, (list, tuple)) else [axis])
if where is None:
where = convert(True)
outputs = tuple(_expr.Reduce(combiner, expr, axis, where, i)
for i in range(size))
return outputs[0] if size == 1 else outputs
# pylint: disable=keyword-arg-before-vararg
def reducer(expr, axis, where=None, *args):
if isinstance(axis, (_schedule.IterVar, list, tuple)):
assert not args
return _make_reduce(expr, axis, where)
if where is None:
assert not args
return _reduce_directly(expr, axis)
return _reduce_directly(expr, axis, where, *args)
doc_str = """Create a {0} expression over axis.
Parameters
----------
expr : Expr
The source expression.
axis : IterVar
The reduction IterVar axis
where : optional, Expr
Filtering predicate of the reduction.
Returns
-------
value : Expr
The result value.
Example
-------
.. code-block:: python
m = tvm.var("m")
n = tvm.var("n")
A = tvm.placeholder((m, n), name="A")
k = tvm.reduce_axis((0, n), name="k")
# there are two way to use this {0} reducer:
# mode 1, accept (expr, axis, where) to produce an Reduce Expr
B = tvm.compute((m,), lambda i: tvm.{0}(A[i, k], axis=k), name="B")
# mode 2, simply use it with multiple Exprs:
{0}_res = tvm.{0}(m, n)
"""
reducer.__doc__ = doc_str.format(name)
return reducer
_init_api("tvm.api")
#pylint: disable=unnecessary-lambda
sum = comm_reducer(lambda x, y: x+y, lambda t: const(0, dtype=t), name="sum")
min = comm_reducer(lambda x, y: _make._OpMin(x, y), max_value, name='min')
max = comm_reducer(lambda x, y: _make._OpMax(x, y), min_value, name='max')