if statement inside a for loop fails to compile

[numba]

if statement inside a for loop fails to compile

[jriehl]

This bug appears to be a nasty corner case in control flow analysis of for-loop code that is being transformed into a while loop. I've added unit tests that illustrate this problem. The case where there is an if-else branch in the for loop is more horrifying since it is causing LLVM to abort due to bad phi node generation. We'll need these new unit tests working for any new release.

[jriehl]

Looks like the while-loop version wasn't complete enough. See also:

https://groups.google.com/a/continuum.io/d/topic/numba-users/tVwSYOdW518/discussion

[jriehl]

This was a whammy of an issue, caused by strange interactions between the dead bytecode Python will generate, phi node generation, and the for-loop transformation. Should be fixed per test results.

[mvaladas2020]

Strange, works for me with numba 0.48.0 but fails with latest 0.51.1...

from numba.decorators import jit
import numba

@jit(arg_types=[numba.double], ret_type=numba.double)
def is_REALLY_five(some_value):
for i in range(5):
if some_value == 5.0:
return 1.0
return 0.0

[gmarkall]

Strange, works for me with numba 0.48.0 but fails with latest 0.51.1...

from numba.decorators import jit
import numba

@jit(arg_types=[numba.double], ret_type=numba.double)
def is_REALLY_five(some_value):
for i in range(5):
if some_value == 5.0:
return 1.0
return 0.0

The numba.decorators module was removed, and you can import jit from numba instead.

If you have any further issues, please start a thread on the Numba Discourse (https://numba.discourse.group) describing your issue / question.

[mvaladas2020]

The numba.decorators module was removed, and you can import jit from numba instead.

If you have any further issues, please start a thread on the Numba Discourse (https://numba.discourse.group) describing your issue / question.

Thank you for your update.

[phanirohith]

I tried both versions numba 0.48.0, 0.51.1, still, the if loop is getting failed.

[esc]

I tried both versions numba 0.48.0, 0.51.1, still, the if loop is getting failed.

@phanirohith thank you for bringing this to our attention. This seems like a regression. Can you please open a new issue and add the code your have as a reproducer. We will take a closer look then. Thank you!