Check if a function is jitted

Numba Support: How do I do ...?
1

I am currently doing hasattr(func, "inspect_llvm") to find out is a function is jitted. It works but …

  1. What is the recommended way to do it?
  2. And to check if was jitted in object or nopython mode?
2

Perhaps you could use the signatures attribute of the dispatcher:

In [1]: import numba as nb

In [2]: @nb.njit
   ...: def foo():
   ...:     acc = 0
   ...:     for i in range(100):
   ...:         acc += i
   ...:     return acc
   ...:

In [3]: foo
Out[3]: CPUDispatcher(<function foo at 0x7fbf7572ab80>)

In [4]: foo.signatures
Out[4]: []

In [5]: foo()
Out[5]: 4950

In [6]: foo.signatures
Out[6]: [()]
3

Or maybe this is even better: https://github.com/numba/numba/blob/master/numba/core/extending.py#L526

4

Thanks @esc I was not aware of this. Do you know if there is a way to distinguish between jitted and nijitted functions?

5

This is now documented: Document numba.extending.is_jitted by stuartarchibald · Pull Request #6472 · numba/numba · GitHub

RE: differentiating between nopython vs “some sort of jit”, there’s two attributes on the dispatcher object:

  1. signatures which is a list of all compiled signatures
  2. nopython_signatures which is a list of nopython mode compiled signatures.

Small demo:

In [1]: from numba import jit

In [2]: @jit
   ...: def foo(x):
   ...:     if x.ndim == 1:
   ...:         object()
   ...:         return 10
   ...:     else:
   ...:         return 4
   ...: 

In [3]: import numpy as np

In [4]: a = np.array([1])

In [5]: foo(a)
<ipython-input-2-bd094eb34546>:1: NumbaWarning: 
Compilation is falling back to object mode WITH looplifting enabled because Function "foo" failed type inference due to: Untyped global name 'object': cannot determine Numba type of <class 'type'>

File "<ipython-input-2-bd094eb34546>", line 4:
def foo(x):
    <source elided>
    if x.ndim == 1:
        object()
        ^

  @jit
<path>/numba/core/object_mode_passes.py:178: NumbaWarning: Function "foo" was compiled in object mode without forceobj=True.

File "<ipython-input-2-bd094eb34546>", line 2:
@jit
def foo(x):
^

  state.func_ir.loc))
<path>/numba/core/object_mode_passes.py:188: NumbaDeprecationWarning: 
Fall-back from the nopython compilation path to the object mode compilation path has been detected, this is deprecated behaviour.

For more information visit http://numba.pydata.org/numba-doc/latest/reference/deprecation.html#deprecation-of-object-mode-fall-back-behaviour-when-using-jit

File "<ipython-input-2-bd094eb34546>", line 2:
@jit
def foo(x):
^

  state.func_ir.loc))
Out[5]: 10

In [6]: b = np.array([[1]])

In [7]: foo(b)
Out[7]: 4

In [8]: foo.signatures
Out[8]: [(array(int64, 1d, C),), (array(int64, 2d, C),)]

In [9]: foo.nopython_signatures
Out[9]: [(array(int64, 2d, C),) -> Literal[int](4)]