### 3.8 Useful Macros and Constants

Global Constant: const int mp_bits_per_limb

  The number of bits per limb.

Macro: __GNU_MP_VERSION
Macro: __GNU_MP_VERSION_MINOR
Macro: __GNU_MP_VERSION_PATCHLEVEL

  The major and minor GMP version, and patch level, respectively, as integers. For GMP i.j, these numbers will be i, j, and 0, respectively. For GMP i.j.k, these numbers will be i, j, and k, respectively.

Global Constant: const char * const gmp_version

  The GMP version number, as a null-terminated string, in the form “i.j.k”. This release is `"6.1.0"`. Note that the format “i.j” was used, before version 4.3.0, when k was zero.

Macro: __GMP_CC
Macro: __GMP_CFLAGS

  The compiler and compiler flags, respectively, used when compiling GMP, as strings.