mpz_get_si: possible undefined behaviour? [Was: Micro-GMP]

[Vincent Lefevre]

On 2018-12-04 13:45:10 +0100, Torbjorn Granlund wrote:
> Pedro Gimeno <gmpdevel at formauri.es> writes:
> 
>   An assertion of LONG_MIN < -LONG_MAX should make the code safe in that case.
> 
> Does The Standard even guarantee thet there are about as many negative
> and positive number?
> 
> I am really worried that GMP might not properly on a machine where
> LONG_MIN = -17 while LONG_MAX = 2^32-18.

This is not possible. The C standard specifies the possible
representations:
  * two's complement, which yields LONG_MIN = - LONG_MAX - 1
  * ones' complement, which yields LONG_MIN = - LONG_MAX
  * sign-magnitude, which yields LONG_MIN = - LONG_MAX

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Vincent Lefèvre <vincent at vinc17.net> - Web: <https://www.vinc17.net/>
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