micropython / micropython/micropython
Overflow converting -2147483648 to int when using MPZ
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- C
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Description
When MICROPY_LONGINT_IMPL == MICROPY_LONGINT_IMPL_MPZ, calling mp_obj_get_int() for a Python variable that contains the value -2147483648 results in an overflow converting long int to machine word error.
If MICROPY_LONGINT_IMPL == MICROPY_LONGINT_IMPL_LONGLONG instead, the conversion works OK.
Is the MPZ overflow check incorrect?
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Research direction
Start by locating mp_obj_get_int() and the MPZ implementation of integer-to-machine-word conversion, then compare its boundary handling with the LONGLONG path. Reproduce the conversion for -2147483648 with MICROPY_LONGINT_IMPL_MPZ enabled and verify that the value no longer raises an overflow error.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- c
- Domain
- embedded-iot
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100