tvm.te¶
Namespace for Tensor Expression Language
Functions:
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Create a new experssion of the union of all conditions in the arguments |
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Create a new expression of the intersection of all conditions in the |
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minimum value of dtype |
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maximum value of dtype |
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Trace tensor data at the runtime. |
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Take exponential of input x. |
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Take gauss error function of the input x. |
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Take hyperbolic tanh of input x. |
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Quick function to get sigmoid |
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Take log of input x. |
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Take tan of input x. |
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Take cos of input x. |
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Take sin of input x. |
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Take square root of input x. |
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Take reciprocal of square root of input x. |
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Take floor of float input x. |
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Take ceil of float input x. |
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Take sinh of input x. |
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Take cosh of input x. |
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Take log2 of input x. |
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Take log10 of input x. |
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Take asin of input x. |
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Take asinh of input x. |
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Take acos of input x. |
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Take acos of input x. |
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Take atan of input x. |
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Take atanh of input x. |
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Get truncated value of the input. |
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Get absolute value of the input element-wise. |
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Round elements of the array to the nearest integer. |
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Round elements of the array to the nearest integer. |
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x power y |
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Count the number of set bits in input x. |
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Return the remainder of x divided by y with the same sign as x. |
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Conditional selection expression. |
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Check if input value is Nan. |
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Check if input value is finite. |
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Check if input value is infinite. |
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Compute a / b as in C/C++ semantics. |
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Compute floor(a / b) where a and b are non-negative. |
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Compute the remainder of indexdiv. |
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Compute the truncdiv of two expressions. |
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Compute the truncmod of two expressions. |
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Compute the floordiv of two expressions. |
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Compute the floormod of two expressions. |
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Create a commutative reducer for reduction. |
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Create a min expression over axis. |
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Create a max expression over axis. |
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Create a sum expression over axis. |
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Generic add operator. |
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Generic subtract operator. |
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Generic multiply operator. |
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Create a schedule for list of ops |
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Declare a tensor intrinsic function. |
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The operator tag scope. |
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Construct an empty tensor object. |
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Construct a new tensor by computing over the shape domain. |
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Construct new tensors by scanning over axis. |
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Compute several tensors via an extern function. |
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Create a new variable with specified name and dtype |
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Create a new variable represents a tensor shape size, which is non-negative. |
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Create a new constant with specified value and dtype |
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Create a new IterVar to represent thread index. |
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Create a new IterVar for reduction. |
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Create a TensorIR PrimFunc from tensor expression |
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Compute tensors via a schedulable TIR PrimFunc |
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Perform reverse-mode automatic differentiation. |
Classes:
Schedule for all the stages. |
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A Stage represents schedule for one operation. |
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Specialized condition to enable op specialization. |
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Auxiliary data structure for enable slicing syntax from tensor. |
Tensor object, to construct, see function.Tensor |
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Placeholder operation. |
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Scalar operation. |
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Tensor operation. |
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Scan operation. |
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External operation. |
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Hybrid operation. |
- tvm.te.any(*args, span=None)¶
Create a new experssion of the union of all conditions in the arguments
- Parameters
- Returns
expr – Expression
- Return type
Expr
Alias of
tvm.tir.any()
- tvm.te.all(*args, span=None)¶
- Create a new expression of the intersection of all conditions in the
arguments
- Parameters
- Returns
expr – Expression
- Return type
Expr
Alias of
tvm.tir.all()
- tvm.te.min_value(dtype, span=None)¶
minimum value of dtype
- Parameters
- Returns
value – The minimum value of dtype.
- Return type
tvm.Expr
Alias of
tvm.tir.min_value()
- tvm.te.max_value(dtype: str, span: Optional[tvm.ir.base.Span] = None) Any¶
maximum value of dtype
- Parameters
- Returns
value – The maximum value of dtype.
- Return type
tvm.Expr
Alias of
tvm.tir.max_value()
- tvm.te.trace(args, trace_action='tvm.default_trace_action')¶
Trace tensor data at the runtime.
The trace function allows to trace specific tensor at the runtime. The tracing value should come as last argument. The trace action should be specified, by default tvm.default_trace_action is used.
- Parameters
args (list of Expr or Buffers.) – Positional arguments.
trace_action (str.) – The name of the trace action.
- Returns
call – The call expression.
- Return type
See also
tvm.tir.call_packedCreates packed function.
Alias of
tvm.tir.trace()
- tvm.te.exp(x)¶
Take exponential of input x.
Alias of
tvm.tir.exp()
- tvm.te.erf(x)¶
Take gauss error function of the input x.
Alias of
tvm.tir.erf()
- tvm.te.tanh(x)¶
Take hyperbolic tanh of input x.
Alias of
tvm.tir.tanh()
- tvm.te.sigmoid(x)¶
Quick function to get sigmoid
Alias of
tvm.tir.sigmoid()
- tvm.te.log(x)¶
Take log of input x.
Alias of
tvm.tir.log()
- tvm.te.tan(x)¶
Take tan of input x.
Alias of
tvm.tir.tan()
- tvm.te.cos(x)¶
Take cos of input x.
Alias of
tvm.tir.cos()
- tvm.te.sin(x)¶
Take sin of input x.
Alias of
tvm.tir.sin()
- tvm.te.sqrt(x)¶
Take square root of input x.
Alias of
tvm.tir.sqrt()
- tvm.te.rsqrt(x)¶
Take reciprocal of square root of input x.
Alias of
tvm.tir.rsqrt()
- tvm.te.floor(x: tvm.tir.expr.PrimExprWithOp, span=None)¶
Take floor of float input x.
- Parameters
- Returns
y – The result.
- Return type
Alias of
tvm.tir.floor()
- tvm.te.ceil(x, span=None)¶
Take ceil of float input x.
- Parameters
- Returns
y – The result.
- Return type
Alias of
tvm.tir.ceil()
- tvm.te.sinh(x)¶
Take sinh of input x.
Alias of
tvm.tir.sinh()
- tvm.te.cosh(x)¶
Take cosh of input x.
Alias of
tvm.tir.cosh()
- tvm.te.log2(x)¶
Take log2 of input x.
Alias of
tvm.tir.log2()
- tvm.te.log10(x)¶
Take log10 of input x.
Alias of
tvm.tir.log10()
- tvm.te.asin(x)¶
Take asin of input x.
Alias of
tvm.tir.asin()
- tvm.te.asinh(x)¶
Take asinh of input x.
Alias of
tvm.tir.asinh()
- tvm.te.acos(x)¶
Take acos of input x.
Alias of
tvm.tir.acos()
- tvm.te.acosh(x)¶
Take acos of input x.
Alias of
tvm.tir.acosh()
- tvm.te.atan(x)¶
Take atan of input x.
Alias of
tvm.tir.atan()
- tvm.te.atanh(x)¶
Take atanh of input x.
Alias of
tvm.tir.atanh()
- tvm.te.trunc(x, span=None)¶
Get truncated value of the input.
The truncated value of the scalar x is the nearest integer i which is closer to zero than x is.
- Parameters
- Returns
y – The result.
- Return type
Alias of
tvm.tir.trunc()
- tvm.te.abs(x, span=None)¶
Get absolute value of the input element-wise.
- Parameters
- Returns
y – The result.
- Return type
Alias of
tvm.tir.abs()
- tvm.te.round(x, span=None)¶
Round elements of the array to the nearest integer.
- Parameters
- Returns
y – The result.
- Return type
Alias of
tvm.tir.round()
- tvm.te.nearbyint(x, span=None)¶
Round elements of the array to the nearest integer. This intrinsic uses llvm.nearbyint instead of llvm.round which is faster but will results different from te.round. Notably nearbyint rounds according to the rounding mode, whereas te.round (llvm.round) ignores that. For differences between the two see: https://en.cppreference.com/w/cpp/numeric/math/round https://en.cppreference.com/w/cpp/numeric/math/nearbyint
- Parameters
- Returns
y – The result.
- Return type
Alias of
tvm.tir.nearbyint()
- tvm.te.power(x, y, span=None)¶
x power y
- Parameters
- Returns
z – The result.
- Return type
Alias of
tvm.tir.power()
- tvm.te.popcount(x)¶
Count the number of set bits in input x.
Alias of
tvm.tir.popcount()
- tvm.te.fmod(x, y)¶
Return the remainder of x divided by y with the same sign as x.
- Parameters
- Returns
z – The result.
- Return type
Alias of
tvm.tir.fmod()
- tvm.te.if_then_else(cond, t, f, span=None)¶
Conditional selection expression.
- Parameters
- Returns
result – The result of conditional expression.
- Return type
Note
Unlike Select, if_then_else will not execute the branch that does not satisfy the condition. You can use it to guard against out of bound access. Unlike Select, if_then_else cannot be vectorized if some lanes in the vector have different conditions.
Alias of
tvm.tir.if_then_else()
- tvm.te.isnan(x, span=None)¶
Check if input value is Nan.
- Parameters
- Returns
y – The result.
- Return type
Alias of
tvm.tir.isnan()
- tvm.te.isfinite(x, span=None)¶
Check if input value is finite.
- Parameters
- Returns
y – The result.
- Return type
Alias of
tvm.tir.isfinite()
- tvm.te.isinf(x, span=None)¶
Check if input value is infinite.
- Parameters
- Returns
y – The result.
- Return type
Alias of
tvm.tir.isinf()
- tvm.te.div(a, b, span=None)¶
Compute a / b as in C/C++ semantics.
- Parameters
- Returns
res – The result expression.
- Return type
Note
When operands are integers, returns truncdiv(a, b, span).
Alias of
tvm.tir.div()
- tvm.te.indexdiv(a, b, span=None)¶
Compute floor(a / b) where a and b are non-negative.
- Parameters
- Returns
res – The result expression.
- Return type
Note
Use this function to split non-negative indices. This function may take advantage of operands’ non-negativeness.
Alias of
tvm.tir.indexdiv()
- tvm.te.indexmod(a, b, span=None)¶
Compute the remainder of indexdiv. a and b are non-negative.
- Parameters
- Returns
res – The result expression.
- Return type
Note
Use this function to split non-negative indices. This function may take advantage of operands’ non-negativeness.
Alias of
tvm.tir.indexmod()
- tvm.te.truncdiv(a, b, span=None)¶
Compute the truncdiv of two expressions.
- Parameters
- Returns
res – The result expression.
- Return type
Note
This is the default integer division behavior in C.
Alias of
tvm.tir.truncdiv()
- tvm.te.truncmod(a, b, span=None)¶
Compute the truncmod of two expressions.
- Parameters
- Returns
res – The result expression.
- Return type
Note
This is the default integer division behavior in C.
Alias of
tvm.tir.truncmod()
- tvm.te.floordiv(a, b, span=None)¶
Compute the floordiv of two expressions.
- Parameters
- Returns
res – The result expression.
- Return type
Alias of
tvm.tir.floordiv()
- tvm.te.floormod(a, b, span=None)¶
Compute the floormod of two expressions.
- Parameters
- Returns
res – The result expression.
- Return type
Alias of
tvm.tir.floormod()
- tvm.te.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 – A function which creates a reduce expression over axis. There are two ways to use it:
accept (expr, axis, where) to produce an Reduce Expr on specified axis;
simply use it with multiple Exprs.
- Return type
function
Example
n = te.var("n") m = te.var("m") mysum = te.comm_reducer(lambda x, y: x+y, lambda t: tvm.tir.const(0, dtype=t), name="mysum") A = te.placeholder((n, m), name="A") k = te.reduce_axis((0, m), name="k") B = te.compute((n,), lambda i: mysum(A[i, k], axis=k), name="B")
Alias of
tvm.tir.comm_reducer()
- tvm.te.min(expr, axis, where=None, init=None, *args)¶
Create a min expression over axis.
- Parameters
- Returns
value – The result value.
- Return type
Example
m = te.var("m") n = te.var("n") A = te.placeholder((m, n), name="A") k = te.reduce_axis((0, n), name="k") # there are two way to use this min reducer: # mode 1, accept (expr, axis, where) to produce an Reduce Expr # tvm.min represents tvm.te.min or tvm.tir.min. B = te.compute((m,), lambda i: tvm.min(A[i, k], axis=k), name="B") # mode 2, simply use it with multiple Exprs: min_res = tvm.min(m, n)
Alias of
tvm.tir.min()
- tvm.te.max(expr, axis, where=None, init=None, *args)¶
Create a max expression over axis.
- Parameters
- Returns
value – The result value.
- Return type
Example
m = te.var("m") n = te.var("n") A = te.placeholder((m, n), name="A") k = te.reduce_axis((0, n), name="k") # there are two way to use this max reducer: # mode 1, accept (expr, axis, where) to produce an Reduce Expr # tvm.max represents tvm.te.max or tvm.tir.max. B = te.compute((m,), lambda i: tvm.max(A[i, k], axis=k), name="B") # mode 2, simply use it with multiple Exprs: max_res = tvm.max(m, n)
Alias of
tvm.tir.max()
- tvm.te.sum(expr, axis, where=None, init=None, *args)¶
Create a sum expression over axis.
- Parameters
- Returns
value – The result value.
- Return type
Example
m = te.var("m") n = te.var("n") A = te.placeholder((m, n), name="A") k = te.reduce_axis((0, n), name="k") # there are two way to use this sum reducer: # mode 1, accept (expr, axis, where) to produce an Reduce Expr # tvm.sum represents tvm.te.sum or tvm.tir.sum. B = te.compute((m,), lambda i: tvm.sum(A[i, k], axis=k), name="B") # mode 2, simply use it with multiple Exprs: sum_res = tvm.sum(m, n)
Alias of
tvm.tir.sum()
- tvm.te.add(lhs, rhs, span=None)¶
Generic add operator.
- Parameters
- Returns
op – The result Expr of add operaton.
- Return type
tvm.Expr
Alias of
tvm.tir.add()
- tvm.te.subtract(lhs, rhs, span=None)¶
Generic subtract operator.
- Parameters
- Returns
op – The result Expr of subtract operaton.
- Return type
tvm.Expr
Alias of
tvm.tir.subtract()
- tvm.te.multiply(lhs, rhs, span=None)¶
Generic multiply operator.
- Parameters
- Returns
op – The result Expr of multiply operaton.
- Return type
tvm.Expr
Alias of
tvm.tir.multiply()
- class tvm.te.Schedule¶
Schedule for all the stages.
Methods:
Build a normalized schedule from the current schedule.
create_group(outputs, inputs[, include_inputs])Create stage group by giving output and input boundary.
cache_read(tensor, scope, readers)Create a cache read of original tensor for readers.
cache_write(tensor, scope)Create a cache write of original tensor, before storing into tensor.
rfactor(tensor, axis[, factor_axis])Factor a reduction axis in tensor's schedule to be an explicit axis.
- normalize()¶
Build a normalized schedule from the current schedule.
Insert necessary rebase to make certain iter var to start from 0. This is needed before bound inference and followup step.
- Returns
sch – The normalized schedule.
- Return type
- create_group(outputs, inputs, include_inputs=False)¶
Create stage group by giving output and input boundary.
The operators between outputs and inputs are placed as member of group. outputs are include in the group, while inputs are not included.
- Parameters
outputs (list of Tensors) – The outputs of the group.
inputs (list of Tensors) – The inputs of the group.
include_inputs (boolean, optional) – Whether include input operations in the group if they are used by outputs.
- Returns
group – A virtual stage represents the group, user can use compute_at to move the attachment point of the group.
- Return type
- cache_read(tensor, scope, readers)¶
Create a cache read of original tensor for readers.
This will mutate the body of the readers. A new cache stage will be created for the tensor. Call this before doing any split/fuse schedule.
- cache_write(tensor, scope)¶
Create a cache write of original tensor, before storing into tensor.
This will mutate the body of the tensor. A new cache stage will created before feed into the tensor.
This function can be used to support data layout transformation. If there is a split/fuse/reorder on the data parallel axis of tensor before cache_write is called. The intermediate cache stores the data in the layout as the iteration order of leave axis. The data will be transformed back to the original layout in the original tensor. User can further call compute_inline to inline the original layout and keep the data stored in the transformed layout.
- rfactor(tensor, axis, factor_axis=0)¶
Factor a reduction axis in tensor’s schedule to be an explicit axis.
This will create a new stage that generated the new tensor with axis as the first dimension. The tensor’s body will be rewritten as a reduction over the factored tensor.
- class tvm.te.Stage¶
A Stage represents schedule for one operation.
Methods:
split(parent[, factor, nparts])Split the stage either by factor providing outer scope, or both
fuse(*args)Fuse multiple consecutive iteration variables into a single iteration variable.
set_scope(scope)Set the thread scope of this stage
bind(ivar, thread_ivar)Bind ivar to thread index thread_ivar
env_threads(threads)Mark threads to be launched at the outer scope of composed op.
set_store_predicate(predicate)Set predicate under which store to the array can be performed.
compute_at(parent, scope)Attach the stage at parent's scope
Mark stage as inline
Attach the stage at parent, and mark it as root
reorder(*args)reorder the arguments in the specified order.
tile(x_parent, y_parent, x_factor, y_factor)Perform tiling on two dimensions
vectorize(var)Vectorize the iteration.
tensorize(var, tensor_intrin)Tensorize the computation enclosed by var with tensor_intrin
unroll(var)Unroll the iteration.
parallel(var)Parallelize the iteration.
pragma(var, pragma_type[, pragma_value])Annotate the iteration with pragma
prefetch(tensor, var, offset)Prefetch the specified variable
storage_align(axis, factor, offset)Set alignment requirement for specific axis
Compute the current stage via double buffering.
Compute the current stage via rolling buffering.
transform_layout(mapping_function)Defines the layout transformation for the current stage's tensor.
- split(parent, factor=None, nparts=None)¶
Split the stage either by factor providing outer scope, or both
- Parameters
parent (IterVar) – The parent iter var.
factor (Expr, optional) – The splitting factor
nparts (Expr, optional) – The number of outer parts.
- Returns
outer (IterVar) – The outer variable of iteration.
inner (IterVar) – The inner variable of iteration.
- fuse(*args)¶
Fuse multiple consecutive iteration variables into a single iteration variable.
fused = fuse(…fuse(fuse(args[0], args[1]), args[2]),…, args[-1]) The order is from outer to inner.
- Parameters
args (list of IterVars) – Itervars that proceeds each other
- Returns
fused – The fused variable of iteration.
- Return type
- set_scope(scope)¶
Set the thread scope of this stage
- Parameters
scope (str) – The thread scope of this stage
- bind(ivar, thread_ivar)¶
Bind ivar to thread index thread_ivar
- env_threads(threads)¶
Mark threads to be launched at the outer scope of composed op.
- Parameters
threads (list of threads) – The threads to be launched.
- set_store_predicate(predicate)¶
Set predicate under which store to the array can be performed.
Use this when there are duplicated threads doing the same store and we only need one of them to do the store.
- Parameters
predicate (Expr) – The guard condition fo store.
- compute_at(parent, scope)¶
Attach the stage at parent’s scope
- compute_root()¶
Attach the stage at parent, and mark it as root
- Parameters
parent (Stage) – The parent stage
- reorder(*args)¶
reorder the arguments in the specified order.
- Parameters
args (list of IterVar) – The order to be ordered
- tile(x_parent, y_parent, x_factor, y_factor)¶
Perform tiling on two dimensions
The final loop order from outmost to inner most are [x_outer, y_outer, x_inner, y_inner]
- Parameters
- Returns
x_outer (IterVar) – Outer axis of x dimension
y_outer (IterVar) – Outer axis of y dimension
x_inner (IterVar) – Inner axis of x dimension
p_y_inner (IterVar) – Inner axis of y dimension
- tensorize(var, tensor_intrin)¶
Tensorize the computation enclosed by var with tensor_intrin
- Parameters
var (IterVar) – The iteration boundary of tensorization.
tensor_intrin (TensorIntrin) – The tensor intrinsic used for computation.
- parallel(var)¶
Parallelize the iteration.
- Parameters
var (IterVar) – The iteration to be parallelized.
- pragma(var, pragma_type, pragma_value=None)¶
Annotate the iteration with pragma
This will translate to a pragma_scope surrounding the corresponding loop generated. Useful to support experimental features and extensions.
- Parameters
Note
Most pragmas are advanced/experimental features and may subject to change. List of supported pragmas:
debug_skip_region
Force skip the region marked by the axis and turn it into no-op. This is useful for debug purposes.
parallel_launch_point
Specify to launch parallel threads outside the specified iteration loop. By default the threads launch at the point of parallel construct. This pragma moves the launching point to even outer scope. The threads are launched once and reused across multiple parallel constructs as BSP style program.
parallel_barrier_when_finish
Insert a synchronization barrier between working threads after the specified loop iteration finishes.
parallel_stride_pattern
Hint parallel loop to execute in strided pattern.
for (int i = task_id; i < end; i += num_task)
- prefetch(tensor, var, offset)¶
Prefetch the specified variable
- storage_align(axis, factor, offset)¶
Set alignment requirement for specific axis
This ensures that stride[axis] == k * factor + offset for some k. This is useful to set memory layout to for more friendly memory access pattern. For example, we can set alignment to be factor=2, offset=1 to avoid bank conflict for thread access on higher dimension in GPU shared memory.
- double_buffer()¶
Compute the current stage via double buffering.
This can only be applied to intermediate stage. This will double the storage cost of the current stage. Can be useful to hide load latency.
- rolling_buffer()¶
Compute the current stage via rolling buffering.
This can only be applied to intermediate stage. This will change the storage cost of the current stage.
- transform_layout(mapping_function: Callable[[...], List[tvm.ir.expr.PrimExpr]])¶
Defines the layout transformation for the current stage’s tensor.
The map from initial_indices to final_indices must be an invertible affine transformation. This method may be called more than once for a given tensor, in which case each transformation is applied sequentially.
If the stage is a ComputeOp, then the iteration order of the compute stage is rewritten to be a row-major traversal of the tensor, and the new loop iteration variables are returned. For all other stages, the loop iteration order is unmodified, and the return value is None.
- Parameters
mapping_function (Callable[..., List[tvm.tir.PrimExpr]]) – A callable that accepts N arguments of type tvm.tir.Var, and outputs a list of PrimExpr. The input arguments represent the location of a value in the current stage’s tensor, using the pre-transformation layout. The return value of the function gives the location of that value in the current stage’s tensor, using the post-transformation layout.
- Returns
new_iter_vars – If the stage is a ComputeOp, then the return will be the updated loop iteration variables over the data array, in the same order as the output values from the mapping_function.
Otherwise, the return value is None.
- Return type
Optional[List[tvm.tir.IterVar]]
Examples
# ``A`` is a tensor whose compute definition is in NHWC # format, and should be transformed into NCHWc format. s[A].transform_layout( lambda n,h,w,c: [n, c//4, h, w, c%4] )
# ``A`` is a tensor whose compute definition is in an # arbitrary format, and should be transformed such that # the last index is split, with the slower-changing index # of the split placed at the slowest changing dimension. s[A].transform_layout( lambda *indices, i: [i//4, *indices, i%4] )
# ``B`` is a tensor defined by te.compute to be a copy of # ``A`, and should be transformed such that ``B``'s layout # is a transpose of ``A``'s layout. The loop iteration # that computes ``B`` will correspond to ``B``'s memory # layout. A = te.placeholder([n,m]) B = te.compute(A.shape, lambda i,j: A[i,j]) s = te.create_schedule(B.op) s[B].transform_layout(lambda i,j: [j,i])
- tvm.te.create_schedule(ops)¶
Create a schedule for list of ops
- Parameters
ops (list of Operations) – The source expression.
- Returns
sch – The created schedule.
- Return type
- class tvm.te.SpecializedCondition(conditions)¶
Specialized condition to enable op specialization.
Methods:
current()Returns the current specialized condition
- static current()¶
Returns the current specialized condition
- class tvm.te.TensorSlice(tensor, indices)¶
Auxiliary data structure for enable slicing syntax from tensor.
Methods:
asobject()Convert slice to object.
Attributes:
Data content of the tensor.
- asobject()¶
Convert slice to object.
- property dtype¶
Data content of the tensor.
- class tvm.te.Tensor¶
Tensor object, to construct, see function.Tensor
Attributes:
Dimension of the tensor.
Axis of the tensor.
The corressponding
Operation.The output value index the tensor corresponds to.
The output shape of the tensor.
- property ndim¶
Dimension of the tensor.
- property axis¶
Axis of the tensor.
- property op¶
The corressponding
Operation.
- property value_index¶
The output value index the tensor corresponds to.
- property shape¶
The output shape of the tensor.
- tvm.te.decl_tensor_intrin(op, fcompute, name='tensor_intrin', binds=None, scalar_params=None, default_buffer_params=None)¶
Declare a tensor intrinsic function.
- Parameters
op (Operation) – The symbolic description of the intrinsic operation
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
tvm.tir.Buffer) - Placeholder for each inputsouts (list of
tvm.tir.Buffer) - Placeholder for each outputs
Returns
stmt (
tvm.tir.Stmt, or tuple of three stmts)If a single stmt is returned, it represents the body
If tuple of three stmts are returned they corresponds to body, reduce_init, reduce_update
name (str, optional) – The name of the intrinsic.
binds (dict of
Tensortotvm.tir.Buffer, optional) – Dictionary that maps the Tensor to Buffer which specified the data layout requirement of the function. By default, a new compact buffer is created for each tensor in the argument.scalar_params (a list of variables used by op, whose values will be passed) – as scalar_inputs when the tensor intrinsic is called.
default_buffer_params (Optional[dict]) – Dictionary of buffer arguments to be passed when constructing a buffer.
- Returns
intrin – A TensorIntrin that can be used in tensorize schedule.
- Return type
- tvm.te.tag_scope(tag)¶
The operator tag scope.
- Parameters
tag (str) – The tag name.
- Returns
tag_scope – The tag scope object, which can be used as decorator or context manger.
- Return type
TagScope
Example
n = te.var('n') m = te.var('m') l = te.var('l') A = te.placeholder((n, l), name='A') B = te.placeholder((m, l), name='B') k = te.reduce_axis((0, l), name='k') with tvm.te.tag_scope(tag='matmul'): C = te.compute((n, m), lambda i, j: te.sum(A[i, k] * B[j, k], axis=k)) # or use tag_scope as decorator @tvm.te.tag_scope(tag="conv") def compute_relu(data): return te.compute(data.shape, lambda *i: tvm.tir.Select(data(*i) < 0, 0.0, data(*i)))
- tvm.te.placeholder(shape, dtype=None, name='placeholder')¶
Construct an empty tensor object.
- tvm.te.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 – The created tensor
- Return type
- tvm.te.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 – The created tensor or tuple of tensors contains multiple outputs.
- Return type
Tensor or list of Tensors
Example
# 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)
- tvm.te.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
tvm.tir.Buffer) - Placeholder for each inputsouts (list of
tvm.tir.Buffer) - Placeholder for each outputs
Returns
stmt (
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 – The created tensor or tuple of tensors contains multiple outputs.
- Return type
Tensor or list of Tensors
Example
In the code below, C is generated by calling external PackedFunc tvm.contrib.cblas.matmul
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")
- tvm.te.var(name='tindex', dtype='int32', span=None)¶
Create a new variable with specified name and dtype
- tvm.te.size_var(name='size', dtype='int32', span=None)¶
Create a new variable represents a tensor shape size, which is non-negative.
- tvm.te.const(value, dtype='int32', span=None)¶
Create a new constant with specified value and dtype
- tvm.te.thread_axis(dom=None, tag='', name='', span=None)¶
Create a new IterVar to represent thread index.
- Parameters
- Returns
axis – The thread itervar.
- Return type
- tvm.te.reduce_axis(dom, name='rv', thread_tag='', span=None)¶
Create a new IterVar for reduction.
- tvm.te.create_prim_func(ops: List[tvm.te.tensor.Tensor], index_dtype_override: Optional[str] = None) tvm.tir.function.PrimFunc¶
Create a TensorIR PrimFunc from tensor expression
- Parameters
ops (List[Tensor]) – The source expression.
Example
We define a matmul kernel using following code:
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:
@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.grid(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 – The created function.
- Return type
- tvm.te.extern_primfunc(input_tensors: List[tvm.te.tensor.Tensor], primfunc: tvm.tir.function.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 – The created tensor or tuple of tensors if it contains multiple outputs.
- Return type
Tensor or list of Tensors
Example
In the code below, a TVMScript defined TIR PrimFunc is inlined into a TE ExternOp. Applying te.create_prim_func on this
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)
- class tvm.te.PlaceholderOp¶
Placeholder operation.
- class tvm.te.ComputeOp¶
Scalar operation.
- class tvm.te.TensorComputeOp¶
Tensor operation.
- class tvm.te.ScanOp¶
Scan operation.
Attributes:
Represent the scan axis, only defined when it is a ScanOp
- property scan_axis¶
Represent the scan axis, only defined when it is a ScanOp
- class tvm.te.ExternOp¶
External operation.
- class tvm.te.HybridOp¶
Hybrid operation.
Attributes:
Represent the IterVar axis, also defined when it is a HybridOp
- property axis¶
Represent the IterVar axis, also defined when it is a HybridOp
- tvm.te.gradient(output, inputs, head=None)¶
Perform reverse-mode automatic differentiation.
- Parameters
output (Tensor) – The tensor to differentiate.
inputs (List[Tensor]) – The list of input tensors to be differentiated wrt.
head (Tensor) – The adjoint of the output, in other words, some tensor, by which the Jacobians will be multiplied. Its shape must be of the form prefix + output.shape. If None is passed, the identity tensor of shape output.shape + output.shape will be used.
- Returns
tensors – The result gradient, in the same order as the inputs
- Return type
List[Tensor]
Example
x = tvm.placeholder((32, 3, 28, 28), name='x') w1 = tvm.placeholder((10, 3, 3, 3), name='w1') w2 = tvm.placeholder((10, 10, 3, 3), name='w2') z1 = topi.nn.conv2d(x, w1, 1, 1, 1) z2 = topi.nn.conv2d(z1, w2, 1, 1, 1) y = topi.sum(z2) # produce gradients [dw1, dw2] = tvm.gradient(y, [w1, w2]) # produce Jacobians [jw1, jw2] = tvm.gradient(z2, [w1, w2]) # produce gradients, the head adjoint for z2 is provided manually [dw1, dw2] = tvm.gradient(z2, [w1, w2], topi.full_like(z2, 1.0))
tvm.te.hybrid¶
Hybrid Programming APIs of TVM Python Package.
This package maps a subset of python to HalideIR so that: 1. Users can write some preliminary versions of the computation patterns have not been supported yet and verify it across the real execution and python semantic emulation. 2. So far, it is a text format dedicated to HalideIR Phase 0. Refer tvm.lower for more details. A larger ambition of this module is to support all levels of HalideIR.
Functions:
|
A wrapper call of decorator package, differs to call time |
|
Another level of wrapper |
|
Decorate a python function function as hybrid script. |
|
Dump the current schedule to hybrid module |
Classes:
|
The usage of Hybrid Module is very similar to conventional TVM module, but conventional TVM module requires a function body which is already fully lowered. |
- tvm.te.hybrid.decorate(func, fwrapped)¶
A wrapper call of decorator package, differs to call time
- Parameters
func (function) – The original function
fwrapped (function) – The wrapped function
- class tvm.te.hybrid.HybridModule(src=None, name=None)¶
The usage of Hybrid Module is very similar to conventional TVM module, but conventional TVM module requires a function body which is already fully lowered. This contradicts to the fact that Hybrid Module is originally a text format for Phase 0 HalideIR. Thus, a totally separated module is defined.
Methods:
load(path)Load the module from a python file
- tvm.te.hybrid.source_to_op(src, args, symbols, closure_vars)¶
Another level of wrapper
- Parameters
src (ast.node or str) – If an ast.node, then directly lower it. If a str, then parse it to ast and lower it.
args (list of Tensors or Vars) – The argument lists to the function. It is NOT encouraged to write a function without arguments. It is NOT encouraged to write a function with side effect.
symbols (list of str) – The symbol list of the global context of the function.
closure_vars (dict) – A dict of external name reference captured by this function.
- Returns
res – The result of output tensors of the formed OpNode.
- Return type
list of output tensors
- tvm.te.hybrid.script(pyfunc)¶
Decorate a python function function as hybrid script.
The hybrid function support emulation mode and parsing to the internal language IR.
- Returns
hybrid_func – A decorated hybrid script function.
- Return type
function
- tvm.te.hybrid.build(sch, inputs, outputs, name='hybrid_func')¶
Dump the current schedule to hybrid module
- Parameters
sch (tvm.te.Schedule) – The schedule to be dumped
inputs (An array of Tensors or Vars) – The inputs of the function body
outputs (An array of Tensors) – The outputs of the function body
- Returns
module – The built results is wrapped in a HybridModule. The usage of HybridModule is roughly the same as normal TVM-built modules.
- Return type