3.10 Compatibility with older versions

This version of MPIR is upwardly binary compatible with all GMP 5.x, 4.x and 3.x versions, and upwardly compatible at the source level with all 2.x versions, with the following exceptions.

• mpn_gcd had its source arguments swapped as of GMP 3.0, for consistency with other mpn functions.
• mpf_get_prec counted precision slightly differently in GMP 3.0 and 3.0.1, but in 3.1 reverted to the 2.x style.
• mpn_bdivmod provided provisionally in the past has been removed from MPIR 2.7.0.
• MPIR does not support the secure cryptographic functions provided by GMP.
• Full GMP compatibility is only available when the ‘--enable-gmpcompat’ configure option is used.

There are a number of compatibility issues between GMP 1 and GMP 2 that of course also apply when porting applications from GMP 1 to GMP 4 and MPIR 1 and 2. Please see the GMP 2 manual for details.