Function: _def_timer
Class: default
Section: default
C-Name: sd_timer
Prototype:
Help:
Doc: this toggle is either 1 (on) or 0 (off). Every instruction sequence
 in the gp calculator (anything ended by a newline in your input) is timed,
 to some accuracy depending on the hardware and operating system. When
 \tet{timer} is on, each such timing is printed immediately before the
 output as follows:
 \bprog
 ? factor(2^2^7+1)
 time = 108 ms.     \\ this line omitted if 'timer' is 0
 %1 =
 [     59649589127497217 1]

 [5704689200685129054721 1]
 @eprog\noindent (See also \kbd{\#} and \kbd{\#\#}.)

 The time measured is the user \idx{CPU time}, not including the time
 for printing the results. If the time is negligible ($< 1$ ms.), nothing is
 printed: in particular, no timing should be printed when defining a user
 function or an alias, or installing a symbol from the library.

 If you are using a parallel version of \kbd{gp}, the output is more
 complex, such as
 \bprog
 ? isprime( 10^300 + 331 )
 cpu time = 3,206 ms, real time = 1,289 ms. \\ omitted if 'timer' is 0
 %1 = 1
 @eprog\noindent Now, \kbd{real time} is the wallclock time, and \kbd{cpu time}
 is the sum of the CPU times spent by the different threads.

 The default value is \kbd{0} (off).
