http://benji3up2kxewkqfcq7buxk2xd6zwy3zggnurkrm3l4cvwy2iipvyyad.onion/mirrors/gmpdoc/Efficiency.html
On suitable compilers (GCC for instance) this is
inlined too. mpz_add_ui , mpz_sub_ui , mpf_add_ui and mpf_sub_ui benefit from an in-place operation like mpz_add_ui(x,x,y) , since
usually only one or two limbs of x will need to be changed. The same
applies to the full precision mpz_add etc if y is small.