cuda.tile.ensure_constant

cuda.tile.ensure_constant(value, /)

Asserts that the argument is a compile-time constant and returns it.

For example, this can be used to ensure that an if statement is folded at compile time:

SnippetComplete Example

if ct.ensure_constant(2 > 1):
     print("Two is greater than one.")
else:
     ct.static_assert(False)  # This branch will be discarded

Copy

import cuda.tile as ct
import torch

@ct.kernel
def kernel():
    if ct.ensure_constant(2 > 1):
         print("Two is greater than one.")
    else:
         ct.static_assert(False)  # This branch will be discarded


torch.cuda.init()
ct.launch(torch.cuda.current_stream(), (1,), kernel, ())
torch.cuda.synchronize()

Output

Two is greater than one.

StaticAssertionError is raised if the argument is not a compile-time constant:

SnippetComplete Example

ct.ensure_constant(ct.bid(0))

Copy

import cuda.tile as ct
import torch

@ct.kernel
def kernel():
    ct.ensure_constant(ct.bid(0))


torch.cuda.init()
ct.launch(torch.cuda.current_stream(), (1,), kernel, ())
torch.cuda.synchronize()

Output

Traceback (most recent call last):
    ...
StaticAssertionError: Argument of ensure_constant() is not a compile-time constant