Function: gettime
Section: programming/specific
C-Name: gettime
Prototype: l
Help: gettime(): milliseconds of CPU time used since the last call to gettime.
Doc: returns the CPU time (in milliseconds) used since either the last call to
 \kbd{gettime}, or to the beginning of the containing GP instruction (if
 inside \kbd{gp}), whichever came last.

 For a reentrant version, see \tet{getabstime}.

 For a version giving wall-clock time, see \tet{getwalltime}.
