# Time a function

Time a function
You are encouraged to solve this task according to the task description, using any language you may know.

Write a program which uses a timer (with the least granularity available on your system) to time how long a function takes to execute.

Whenever possible, use methods which measure only the processing time used by the current process; instead of the difference in system time between start and finish, which could include time used by other processes on the computer.

This task is intended as a subtask for Measure relative performance of sorting algorithms implementations.

## 11l

Translation of: Nim
```F do_work(x)
V n = x
L(i) 10000000
n += i
R n

F time_func(f)
V start = time:perf_counter()
f()
R time:perf_counter() - start

print(time_func(() -> do_work(100)))```

## 8051 Assembly

Using a timer requires knowledge on two things: the oscillator frequency (which limits the maximum precision) and the desired precision. This code uses a common crystal of 11.0592MHz - but provides values for a few others as examples. This code also uses a precision of 4 bits (2^(-4) = 0.0625 seconds). Those familiar with binary can think of this as a right shift of 4 of the multi-byte value, where the low 4 bits represent the fraction of a second, and the remaining bits represent whole seconds. The maximum time value depends on the number of bytes used and the precision. For x bytes and p precision, the maximum value you can count to is (256^x - 1) * 2^(-p).

```TC	EQU	8 ; number of counter registers
TSTART	EQU	08h ; first register of timer counter
TEND	EQU	TSTART + TC - 1 ; end register of timer counter
; Note: The multi-byte value is stored in Big-endian

_6H	EQU	085h ; 6MHz
_6L	EQU	0edh
_12H	EQU	00bh ; 12MHz
_12L	EQU	0dbh
_110592H	EQU	01eh ; 11.0592MHz
_110592L	EQU	0ffh

; How to calculate timer reload (e.g. for 11.0592MHz):
; Note: 1 machine cycle takes 12 oscillator periods
; 11.0592MHz / 12 * 0.0625 seconds = 57,600 cycles = e100h
; ffffh - e100h = NOT e100h = 1effh

; assuming a 11.0592MHz crystal
TIMERH	EQU	_110592H
TIMERL	EQU	_110592L

;; some timer macros (using timer0)
start_timer macro
setb tr0
endm
stop_timer macro
clr tr0
endm
reset_timer macro
mov tl0, #TIMERL
mov th0, #TIMERH
endm

increment_counter macro ;; increment counter (multi-byte increment)
push psw
push acc
push 0 ; r0
mov r0, #TEND+1
setb c
inc_reg:
dec r0
clr a
mov @r0, a
jnc inc_reg_	; end prematurally if the higher bytes are unchanged
cjne r0, #TSTART, inc_reg
inc_reg_:
; if the carry is set here then the multi byte value has overflowed
pop 0
pop acc
pop psw
endm

ORG RESET
jmp init
ORG TIMER0
jmp timer_0

timer_0: ; interrupt every 6.25ms
stop_timer		; we only want to time the function
reset_timer
increment_counter
start_timer
reti

init:
mov sp, #TEND
setb ea			; enable interrupts
setb et0		; enable timer0 interrupt
mov tmod, #01h		; timer0 16-bit mode
reset_timer

; reset timer counter registers
clr a
mov r0, #TSTART
clear:
mov @r0, a
inc r0
cjne r0, #TEND, clear

start_timer
call function		; the function to time
stop_timer

; at this point the registers from TSTART
; through TEND indicate the current time
; multiplying the 8/16/24/etc length value by 0.0625 (2^-4) gives
; the elapsed number of seconds
; e.g. if the three registers were 02a0f2h then the elapsed time is:
; 02a0f2h = 172,274 and 172,274 * 0.0625 = 10,767.125 seconds
;
; Or alternatively:
; (high byte) 02h = 2 and 2 * 2^(16-4) = 8192
; (mid byte) a0h = 160 and 160 * 2^(8-4) = 2560
; (low byte) f2h = 242 and 242 * 2^(0-4) = 15.125
; 8192 + 2560 + 15.125 = 10,767.125 seconds

jmp \$

function:
; do whatever here
ret

END
```

## ACL2

```(time\$ (nthcdr 9999999 (take 10000000 nil)))
```

Output (for Clozure):

```; (EV-REC *RETURN-LAST-ARG3* ...) took
; 2.53 seconds realtime, 2.48 seconds runtime
; (160,001,648 bytes allocated).
(NIL)```

## Action!

```BYTE RTCLOK1=\$13
BYTE RTCLOK2=\$14
BYTE PALNTSC=\$D014

PROC Count(CARD max)
CARD i

FOR i=1 TO max DO OD
RETURN

CARD FUNC GetFrame()
CARD res
BYTE lsb=res,msb=res+1

lsb=RTCLOK2
msb=RTCLOK1
RETURN (res)

CARD FUNC FramesToMs(CARD frames)
CARD res

IF PALNTSC=15 THEN
res=frames*60
ELSE
res=frames*50
FI
RETURN (res)

PROC Main()
CARD ARRAY c=[1000 2000 5000 10000 20000 50000]
CARD beg,end,diff,diffMs
BYTE i

FOR i=0 TO 5
DO
PrintF("Count to %U takes ",c(i))
beg=GetFrame()
Count(c(i))
end=GetFrame()
diff=end-beg
diffMs=FramesToMs(diff)
PrintF("%U ms%E",diffMs)
OD
RETURN```
Output:
```Count to 1000 takes 50 ms
Count to 2000 takes 100 ms
Count to 5000 takes 300 ms
Count to 10000 takes 600 ms
Count to 20000 takes 1150 ms
Count to 50000 takes 3000 ms
```

```with Ada.Calendar; use Ada.Calendar;

procedure Query_Performance is
type Proc_Access is access procedure(X : in out Integer);
function Time_It(Action : Proc_Access; Arg : Integer) return Duration is
Start_Time : Time := Clock;
Finis_Time : Time;
Func_Arg : Integer := Arg;
begin
Action(Func_Arg);
Finis_Time := Clock;
return Finis_Time - Start_Time;
end Time_It;
procedure Identity(X : in out Integer) is
begin
X := X;
end Identity;
procedure Sum (Num : in out Integer) is
begin
for I in 1..1000 loop
Num := Num + I;
end loop;
end Sum;
Id_Access : Proc_Access := Identity'access;
Sum_Access : Proc_Access := Sum'access;

begin
Put_Line("Identity(4) takes" & Duration'Image(Time_It(Id_Access, 4)) & " seconds.");
Put_Line("Sum(4) takes:" & Duration'Image(Time_It(Sum_Access, 4)) & " seconds.");
end Query_Performance;
```

### Example

```Identity(4) takes 0.000001117 seconds.
Sum(4) takes: 0.000003632 seconds.
```

## Aime

```integer
identity(integer x)
{
x;
}

integer
sum(integer c)
{
integer s;

s = 0;
while (c) {
s += c;
c -= 1;
}

s;
}

real
time_f(integer (*fp)(integer), integer fa)
{
date f, s;
time t;

s.now;

fp(fa);

f.now;

t.ddiff(f, s);

t.microsecond / 1000000r;
}

integer
main(void)
{
o_real(6, time_f(identity, 1));
o_text(" seconds\n");
o_real(6, time_f(sum, 1000000));
o_text(" seconds\n");

0;
}```

## ARM Assembly

Works with: as version Raspberry Pi
```/* ARM assembly Raspberry PI  */
/*  program fcttime.s   */

/* Constantes    */
.equ STDOUT, 1     @ Linux output console
.equ EXIT,   1     @ Linux syscall
.equ WRITE,  4     @ Linux syscall

.equ N1, 1000000   @ loop number
.equ NBMEASURE, 10 @ measure number

/*********************************/
/* Initialized data              */
/*********************************/
.data
szMessError:       .asciz "Error detected !!!!. \n"
szMessSep:         .asciz "****************************\n"
szMessTemps:       .ascii "Function time : "
sSecondes:         .fill 10,1,' '
.ascii " s "
sMicroS:           .fill 10,1,' '
.asciz " micros\n"

szCarriageReturn:  .asciz "\n"
/*********************************/
/* UnInitialized data            */
/*********************************/
.bss
.align 4
dwDebut:           .skip 8
dwFin:             .skip 8
/*********************************/
/*  code section                 */
/*********************************/
.text
.global main
main:                                     @ entry of program
mov r1,#1                             @ parameter 1 function
mov r2,#2                             @ parameter 2 function
bl timeMesure
cmp r0,#0
blt 99f
mov r1,#1
mov r2,#2
bl timeMesure
cmp r0,#0
blt 99f
b 100f
99:
@ error
bl affichageMess
100:                                       @ standard end of the program
mov r0, #0                             @ return code
mov r7, #EXIT                          @ request to exit program
svc #0                                 @ perform the system call

/**************************************************************/
/*   examble function sum                                     */
/**************************************************************/
/* r0 contains op 1     */
/* r1 contains op 2     */
sum:
push {lr}                  @ save registres
100:
pop {lr}                   @ restaur registers
bx lr                      @ function return

/**************************************************************/
/*   exemple execution multiplication                         */
/**************************************************************/
/* r0 contains op 1     */
/* r1 contains op 2     */
mult:
push {lr}                  @ save registres
mul r0,r1,r0
100:
pop {lr}                   @ restaur registers
bx lr                      @ function return

/**************************************************************/
/*   Procedure for measuring the execution time of a routine  */
/**************************************************************/
/* r0 contains the function address     */
timeMesure:
push {r1-r8,lr}                      @ save registres
mov r4,r0                            @ save function address
mov r5,r1                            @ save param 1
mov r6,r2                            @ save param 2
mov r8,#0
1:
ldr r0,iAdrdwDebut                   @ start time area
mov r1,#0
mov r7, #0x4e                        @ call system gettimeofday
svc #0
cmp r0,#0                            @ error ?
blt 100f                             @ return error
ldr r7,iMax                          @ run number
mov r0,r5                            @ param function 1
mov r1,r6                            @ param function 2
2:                                       @ loop
blx r4                               @ call of the function to be measured
subs r7,#1                           @ decrement run
bge 2b                               @ loop if not zero
@
ldr r0,iAdrdwFin                     @ end time area
mov r1,#0
mov r7, #0x4e                        @ call system gettimeofday
svc #0
cmp r0,#0                            @ error ?
blt 100f                             @ return error
@ compute time
ldr r0,iAdrdwDebut                   @ start time area
//vidmemtit mesure r0 2
ldr r2,[r0]                          @ secondes
ldr r3,[r0,#4]                       @ micro secondes
ldr r0,iAdrdwFin                     @ end time area
ldr r1,[r0]                          @ secondes
ldr r0,[r0,#4]                       @ micro secondes
sub r2,r1,r2                         @ secondes number
subs r3,r0,r3                        @ microsecondes number
sublt r2,#1                          @ if negative sub 1 seconde to secondes
ldr r1,iSecMicro
mov r0,r2                            @ conversion secondes
bl conversion10
mov r0,r3                            @ conversion microsecondes
bl conversion10
bl affichageMess                     @ display message
cmp r8,#NBMEASURE
ble 1b
bl affichageMess
100:
pop {r1-r8,lr}                       @ restaur registers
bx lr                                @ function return
iMax:                 .int N1
iSecMicro:            .int 1000000

/******************************************************************/
/*     display text with size calculation                         */
/******************************************************************/
/* r0 contains the address of the message */
affichageMess:
push {r0,r1,r2,r7,lr}                   @ save  registres
mov r2,#0                               @ counter length
1:                                          @ loop length calculation
ldrb r1,[r0,r2]                         @ read octet start position + index
cmp r1,#0                               @ if 0 its over
bne 1b                                  @ and loop
@ so here r2 contains the length of the message
mov r1,r0                               @ address message in r1
mov r0,#STDOUT                          @ code to write to the standard output Linux
mov r7, #WRITE                          @ code call system "write"
svc #0                                  @ call systeme
pop {r0,r1,r2,r7,lr}                    @ restaur registers */
bx lr                                   @ return
/******************************************************************/
/*     Converting a register to a decimal                                 */
/******************************************************************/
/* r0 contains value and r1 address area   */
.equ LGZONECAL,   10
conversion10:
push {r1-r4,lr}                         @ save registers
mov r3,r1
mov r2,#LGZONECAL
1:                                          @ start loop
bl divisionpar10                        @ r0 <- dividende. quotient ->r0 reste -> r1
strb r1,[r3,r2]                         @ store digit on area
cmp r0,#0                               @ stop if quotient = 0
subne r2,#1                               @ previous position
bne 1b                                  @ else loop
@ end replaces digit in front of area
mov r4,#0
2:
ldrb r1,[r3,r2]
strb r1,[r3,r4]                         @ store in area begin
cmp r2,#LGZONECAL                       @ end
ble 2b                                  @ loop
mov r1,#' '
3:
strb r1,[r3,r4]
cmp r4,#LGZONECAL                       @ end
ble 3b
100:
pop {r1-r4,lr}                          @ restaur registres
bx lr                                   @return
/***************************************************/
/*   division par 10   signé                       */
/* Thanks to http://thinkingeek.com/arm-assembler-raspberry-pi/*
/* and   http://www.hackersdelight.org/            */
/***************************************************/
/* r0 dividende   */
/* r0 quotient */
/* r1 remainder  */
divisionpar10:
/* r0 contains the argument to be divided by 10 */
push {r2-r4}                           @ save registers  */
mov r4,r0
mov r3,#0x6667                         @ r3 <- magic_number  lower
movt r3,#0x6666                        @ r3 <- magic_number  upper
smull r1, r2, r3, r0                   @ r1 <- Lower32Bits(r1*r0). r2 <- Upper32Bits(r1*r0)
mov r2, r2, ASR #2                     @ r2 <- r2 >> 2
mov r1, r0, LSR #31                    @ r1 <- r0 >> 31
add r0, r2, r1                         @ r0 <- r2 + r1
add r2,r0,r0, lsl #2                   @ r2 <- r0 * 5
sub r1,r4,r2, lsl #1                   @ r1 <- r4 - (r2 * 2)  = r4 - (r0 * 10)
pop {r2-r4}
bx lr                                  @ return```
Output:
```Function time : 0          s 16881      micros
Function time : 0          s 16728      micros
Function time : 0          s 16690      micros
Function time : 0          s 16904      micros
Function time : 0          s 16703      micros
Function time : 0          s 16686      micros
Function time : 0          s 16703      micros
Function time : 0          s 8240       micros
Function time : 0          s 7152       micros
Function time : 0          s 7143       micros
Function time : 0          s 7153       micros
****************************
Function time : 0          s 7153       micros
Function time : 0          s 7143       micros
Function time : 0          s 7153       micros
Function time : 0          s 7151       micros
Function time : 0          s 7151       micros
Function time : 0          s 7144       micros
Function time : 0          s 7153       micros
Function time : 0          s 7177       micros
Function time : 0          s 7143       micros
Function time : 0          s 7156       micros
Function time : 0          s 7154       micros
****************************

```

## Arturo

```benchmark [
print "starting function"
pause 2000
print "function ended"
]
```
Output:
```starting function
function ended
[benchmark] time: 2.005s```

## AutoHotkey

### System time

Uses system time, not process time

```MsgBox % time("fx")
Return

fx()
{
Sleep, 1000
}

time(function, parameter=0)
{
SetBatchLines -1  ; don't sleep for other green threads
StartTime := A_TickCount
%function%(parameter)
Return ElapsedTime := A_TickCount - StartTime . " milliseconds"
}
```

### Using QueryPerformanceCounter

QueryPerformanceCounter allows even more precision:

```MsgBox, % TimeFunction("fx")

TimeFunction(Function, Parameters*) {
SetBatchLines, -1						; SetBatchLines sets the speed of which every new line of coe is run.
DllCall("QueryPerformanceCounter", "Int64*", CounterBefore)	; Start the counter.
DllCall("QueryPerformanceFrequency", "Int64*", Freq)		; Get the frequency of the counter.
%Function%(Parameters*)						; Call the function with it's parameters.
DllCall("QueryPerformanceCounter", "Int64*", CounterAfter)	; End the counter.

; Calculate the speed of which it counted.
Return, (((CounterAfter - CounterBefore) / Freq) * 1000) . " milliseconds."
}

fx() {
Sleep, 1000
}
```

## BaCon

The BaCon TIMER function keeps track of time spent running, in milliseconds (which is also the time unit used by SLEEP). This is not process specific, but a wall clock time counter which starts at 0 during process initialization. As BaCon can easily use external C libraries, process specific CLOCK_PROCESS_CPUTIME_ID clock_gettime could also be used.

```' Time a function
SUB timed()
SLEEP 7000
END SUB

st = TIMER
timed()
et = TIMER
PRINT st, ", ", et
```
Output:
```prompt\$ ./time-function
0, 7000```

## BASIC

Works with: QBasic
```DIM timestart AS SINGLE, timedone AS SINGLE, timeelapsed AS SINGLE

timestart = TIMER
SLEEP 1 'code or function to execute goes here
timedone = TIMER

'midnight check:
IF timedone < timestart THEN timedone = timedone + 86400
timeelapsed = timedone - timestart
```

## BASIC256

```call cont(10000000)
print msec; " milliseconds"

t0 = msec
call cont(10000000)
print msec+t0; " milliseconds"
end

subroutine cont(n)
sum = 0
for i = 1 to n
sum += 1
next i
end subroutine```

## Batch File

Granularity: hundredths of second.

```@echo off
Setlocal EnableDelayedExpansion

call :clock

::timed function:fibonacci series.....................................
set /a a=0 ,b=1,c=1
:loop
if %c% lss 2000000000 echo %c% & set /a c=a+b,a=b, b=c & goto loop
::....................................................................

call :clock

echo  Function executed in %timed% hundredths of second
goto:eof

:clock
if not defined timed set timed=0
for /F "tokens=1-4 delims=:.," %%a in ("%time%") do (
set /A timed = "(((1%%a - 100) * 60 + (1%%b - 100)) * 60 + (1%%c - 100))  * 100 + (1%%d - 100)- %timed%"
)
goto:eof```

## BBC BASIC

```start%=TIME:REM centi-second timer
REM perform processing
lapsed%=TIME-start%
```

## BQN

To execute a function `F` once and get the amount of time it took to execute with value `v`, you can do this:

```F •_timed v
```

`•_timed` is a system value that runs `F` a set number of times and returns the average runtime of the function. Here, since the left argument `𝕨` is omitted, it is run once.

The final result is in seconds.

Here are a few example runs:

```   {0:1;𝕩×𝕊𝕩-1}•_timed 100
8.437800000000001e¯05
{0:1;𝕩×𝕊𝕩-1}•_timed 1000
0.000299545
```

## Bracmat

```( ( time
=   fun funarg t0 ret
.   !arg:(?fun.?funarg)
& clk\$:?t0
& !fun\$!funarg:?ret
& (!ret.flt\$(clk\$+-1*!t0,3) s)
)
& ( fib
=
.   !arg:<2&1
| fib\$(!arg+-1)+fib\$(!arg+-2)
)
& time\$(fib.30)
)```

Output:

`1346269.5,141*10E0 s`

## C

Works with: POSIX version .1-2001

On some system (like GNU/Linux) to be able to use the clock_gettime function you must link with the rt (RealTime) library.

`CLOCK_PROCESS_CPUTIME_ID` is preferred when available (eg. Linux kernel 2.6.12 up), being CPU time used by the current process. (`CLOCK_MONOTONIC` generally includes CPU time of unrelated processes, and may be drifted by `adjtime()`.)

```#include <stdio.h>
#include <time.h>

int identity(int x) { return x; }

int sum(int s)
{
int i;
for(i=0; i < 1000000; i++) s += i;
return s;
}

#ifdef CLOCK_PROCESS_CPUTIME_ID
/* cpu time in the current process */
#define CLOCKTYPE  CLOCK_PROCESS_CPUTIME_ID
#else
/* this one should be appropriate to avoid errors on multiprocessors systems */
#define CLOCKTYPE  CLOCK_MONOTONIC
#endif

double time_it(int (*action)(int), int arg)
{
struct timespec tsi, tsf;

clock_gettime(CLOCKTYPE, &tsi);
action(arg);
clock_gettime(CLOCKTYPE, &tsf);

double elaps_s = difftime(tsf.tv_sec, tsi.tv_sec);
long elaps_ns = tsf.tv_nsec - tsi.tv_nsec;
return elaps_s + ((double)elaps_ns) / 1.0e9;
}

int main()
{
printf("identity (4) takes %lf s\n", time_it(identity, 4));
printf("sum      (4) takes %lf s\n", time_it(sum, 4));
return 0;
}
```

## C#

Using Stopwatch.

```using System;
using System.Linq;
using System.Diagnostics;

class Program {
static void Main(string[] args) {
Stopwatch sw = new Stopwatch();

sw.Start();
DoSomething();
sw.Stop();

Console.WriteLine("DoSomething() took {0}ms.", sw.Elapsed.TotalMilliseconds);
}

static void DoSomething() {

Enumerable.Range(1, 10000).Where(x => x % 2 == 0).Sum();  // Sum even numers from 1 to 10000
}
}
```

Using DateTime.

```using System;
using System.Linq;

class Program {
static void Main(string[] args) {
DateTime start, end;

start = DateTime.Now;
DoSomething();
end = DateTime.Now;

Console.WriteLine("DoSomething() took " + (end - start).TotalMilliseconds + "ms");
}

static void DoSomething() {

Enumerable.Range(1, 10000).Where(x => x % 2 == 0).Sum();  // Sum even numers from 1 to 10000
}
}
```

Output:

```DoSomething() took 1071,5408ms
```

## C++

### Using `ctime`

```#include <ctime>
#include <iostream>
using namespace std;

int identity(int x) { return x; }
int sum(int num) {
for (int i = 0; i < 1000000; i++)
num += i;
return num;
}

double time_it(int (*action)(int), int arg) {
clock_t start_time = clock();
action(arg);
clock_t finis_time = clock();
return ((double) (finis_time - start_time)) / CLOCKS_PER_SEC;
}

int main() {
cout << "Identity(4) takes " << time_it(identity, 4) << " seconds." << endl;
cout << "Sum(4) takes " << time_it(sum, 4) << " seconds." << endl;
return 0;
}
```

Output:

``` Identity(4) takes 0 seconds.
Sum(4) takes 0.01 seconds.
```

### Using `std::chrono`

```// Compile with:
// g++ -std=c++20 -Wall -Wextra -pedantic -O0 func-time.cpp -o func-time

#include <iostream>
#include <chrono>

template<typename f>
double measure(f func) {
auto start = std::chrono::steady_clock::now(); // Starting point
(*func)(); // Run the function
auto end = std::chrono::steady_clock::now(); // End point

return std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count(); // By default, return time by milliseconds
}

/*
Test functions:
identity(): returns a number
addmillion(): add 1,000,000 to a number, one by one, using a for-loop
*/

int identity(int x) { return x; }

for (int i = 0; i < 1000000; i++)
num += i;
return num;
}

int main() {
double time;
time = measure([](){ return identity(10); });
// Shove the function into a lambda function.
// Yeah, I couldn't think of any better workaround.
std::cout << "identity(10)\t\t" << time << " milliseconds / " << time / 1000 << " seconds" << std::endl; // Print it
time = measure([](){ return addmillion(1800); });
std::cout << "addmillion(1800)\t" << time << " milliseconds / " << time / 1000 << " seconds" << std::endl;

return 0;
}
```

Output:

```identity(10)		0 milliseconds / 0 seconds
addmillion(1800)	4 milliseconds / 0.004 seconds
```

## Clojure

```  (defn fib []
(map first
(iterate
(fn [[a b]] [b (+ a b)])
[0 1])))

(time (take 100 (fib)))
```

Output:

```"Elapsed time: 0.028 msecs"
(0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181)
```

## Common Lisp

Common Lisp provides a standard utility for performance measurement, time:

```CL-USER> (time (reduce #'+ (make-list 100000 :initial-element 1)))
Evaluation took:
0.151 seconds of real time
0.019035 seconds of user run time
0.01807 seconds of system run time
0 calls to %EVAL
0 page faults and
2,400,256 bytes consed.
```

(The example output here is from SBCL.)

However, it merely prints textual information to trace output, so the information is not readily available for further processing (except by parsing it in a CL-implementation-specific manner).

The functions get-internal-run-time and get-internal-real-time may be used to get time information programmatically, with at least one-second granularity (and usually more). Here is a function which uses them to measure the time taken for one execution of a provided function:

```(defun timings (function)
(let ((real-base (get-internal-real-time))
(run-base (get-internal-run-time)))
(funcall function)
(values (/ (- (get-internal-real-time) real-base) internal-time-units-per-second)
(/ (- (get-internal-run-time) run-base) internal-time-units-per-second))))

CL-USER> (timings (lambda () (reduce #'+ (make-list 100000 :initial-element 1))))
17/500
7/250
```

## D

```import std.stdio, std.datetime;

int identity(int x) {
return x;
}

int sum(int num) {
foreach (i; 0 .. 100_000_000)
num += i;
return num;
}

double timeIt(int function(int) func, int arg) {
StopWatch sw;
sw.start();
func(arg);
sw.stop();
return sw.peek().usecs / 1_000_000.0;
}

void main() {
writefln("identity(4) takes %f6 seconds.", timeIt(&identity, 4));
writefln("sum(4) takes %f seconds.", timeIt(&sum, 4));
}
```

Output:

```identity(4) takes 0.0000016 seconds.
sum(4) takes 0.522065 seconds.```

### Using Tango

```import tango.io.Stdout;
import tango.time.Clock;

int identity (int x)
{
return x;
}

int sum (int num)
{
for (int i = 0; i < 1000000; i++)
num += i;
return num;
}

double timeIt(int function(int) func, int arg)
{
long before = Clock.now.ticks;
func(arg);
return (Clock.now.ticks - before) / cast(double)TimeSpan.TicksPerSecond;
}

void main ()
{
Stdout.format("Identity(4) takes {:f6} seconds",timeIt(&identity,4)).newline;
Stdout.format("Sum(4) takes {:f6} seconds",timeIt(&sum,4)).newline;
}
```

## Delphi

Works with: Delphi version 6.0

Here is a simple timer object that I use to time different parts of the code, to figure out which parts take the most time and are the best targets for optimization.

The object is based on the TPanel, which means the timer can be dropped on a form where it will display timing data whenever you want.

The time is controlled by four different commands: Reset, Start, StopItalic text and DisplayItalic text.

Reset. Reset zeros the timer. Start. Starts the timer running. Stop. Stops the timer. Displays. Displays the current cumulative time since the first start.

Start and Stop can be moved around the code to control which parts are timed. You can even turn the timer on and off multiple times to messure the combined execution times of multiple different sections of code. You can also move the Start and Stop commands closer and closer together to zoom in on the part of the code that takes the most time to execute.

Finally, since the object is based on the TPanel component, the font, colors and layout can be made to look fancy for placement on the status bar of a program.

```type TResolution=(rsSeconds,rsMiliSeconds);

type TCodeTimer=class(TPanel)
private
FResolution: TResolution;
public
WrkCount,TotCount: longint;
constructor Create(AOwner: TComponent); override;
procedure Reset;
procedure Start;
procedure Stop;
procedure Display;
published
property Resolution: TResolution read FResolution write FResolution default rsMiliSeconds;
end;

function GetHiResTick: integer;
var C: TLargeInteger;
begin
QueryPerformanceCounter(C);
Result:=C;
end;

constructor TCodeTimer.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
FResolution:=rsMiliSeconds;
end;

procedure TCodeTimer.Reset;
begin
WrkCount:=0;
TotCount:=0;
end;

procedure TCodeTimer.Start;
begin
WrkCount:=GetHiResTick;
end;

procedure TCodeTimer.Stop;
begin
TotCount:=TotCount+(GetHiResTick-WrkCount);
end;

procedure TCodeTimer.Display;
begin
else Caption:=FloatToStrF(TotCount/1000,ffFixed,18,3)+' ms.'
end;
```
Output:
```
```

## E

Translation of: Java

— E has no standardized facility for CPU time measurement; this

Works with: E-on-Java

.

```def countTo(x) {
println("Counting...")
for _ in 1..x {}
println("Done!")
}

def MX := <unsafe:java.lang.management.makeManagementFactory>

for count in [10000, 100000] {
countTo(count)
println(`Counting to \$count takes \${(finish-start)//1000000}ms`)
}```

## EasyLang

```func fua lim .
# this is interpreted
i = 1
while i <= lim
sum += i
i += 1
.
return sum
.
start = systime
print fua 1e8
print systime - start
#
fastfunc fub lim .
# this is compiled to wasm
i = 1
while i <= lim
sum += i
i += 1
.
return sum
.
start = systime
print fub 1e8
print systime - start```

## Elena

Translation of: C#

ELENA 6.x :

```import system'calendar;
import system'routines;
import system'math;
import extensions;

someProcess()
{

new Range(0,10000).filterBy::(x => x.mod(2) == 0).summarize();
}

public program()
{
var start := now;

someProcess();

var end := now;

console.printLine("Time elapsed in msec:",(end - start).Milliseconds)
}```
Output:
```Time elapsed in msec:1015
```

## Elixir

Translation of: Erlang

tc/1

```iex(10)> :timer.tc(fn -> Enum.each(1..100000, fn x -> x*x end) end)
{236000, :ok}
```

tc/2

```iex(11)> :timer.tc(fn x -> Enum.each(1..x, fn y -> y*y end) end, [1000000])
{2300000, :ok}
```

tc/3

```iex(12)> :timer.tc(Enum, :to_list, [1..1000000])
{224000,
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41,
42, 43, 44, 45, 46, 47, 48, 49, ...]}
```

## EMal

Translation of: VBA
```fun identity = int by int x
int retval = 0
for int i = 0; i < 1000; ++i
retval = x
end
return retval
end
fun sum = int by int num
int t
for int j = 0; j < 1000; ++j
t = num
for int i = 0; i < 10000; i++
t = t + i
end
end
return t
end
int startTime, finishTime
startTime = time()
identity(1)
finishTime = time()
writeLine("1000 times Identity(1) takes " + (finishTime - startTime) + " milliseconds")
startTime = time()
sum(1)
finishTime = time()
writeLine("1000 times Sum(1) takes " + (finishTime - startTime) + " milliseconds")```
Output:
```1000 times Identity(1) takes 16 milliseconds
1000 times Sum(1) takes 6160 milliseconds
```

## Erlang

Erlang's timer module has three implementations of the tc function.

tc/1 takes a 0-arity function and executes it:

```5> {Time,Result} = timer:tc(fun () -> lists:foreach(fun(X) -> X*X end, lists:seq(1,100000)) end).
{226391,ok}
6> Time/1000000. % Time is in microseconds.
0.226391
7> % Time is in microseconds.
```

tc/2 takes an n-arity function and its arguments:

```9> timer:tc(fun (X) -> lists:foreach(fun(Y) -> Y*Y end, lists:seq(1,X)) end, [1000000]).
{2293844,ok}
```

tc/3 takes a module name, function name and the list of arguments to the function:

```8> timer:tc(lists,seq,[1,1000000]).
{62370,
[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,
23,24,25,26,27|...]}
```

## Euphoria

```atom t
t = time()
some_procedure()
t = time() - t
printf(1,"Elapsed %f seconds.\n",t)```

## F#

The .Net framework provides a Stopwatch class which provides a performance counter.

```open System.Diagnostics
let myfunc data =
let timer = new Stopwatch()
timer.Start()
let result = data |> expensive_processing
timer.Stop()
printf "elapsed %d ms" timer.ElapsedMilliseconds
result
```

## Factor

Works with: Factor version 0.98
```USING: kernel sequences tools.time ;

[ 10000 <iota> sum drop ] time
```
Output:
```Running time: 0.002888635 seconds

dispatch-stats.  - Print method dispatch statistics
gc-events.       - Print all garbage collection events
gc-stats.        - Print breakdown of different garbage collection events
gc-summary.      - Print aggregate garbage collection statistics
```

## Forth

Works with: GNU Forth
```: time: ( "word" -- )
utime 2>R ' EXECUTE
utime 2R> D-
<# # # # # # # [CHAR] . HOLD #S #> TYPE ."  seconds" ;

1000 time: MS  \ 1.000081 seconds ok
```

## Fortran

Works with: Gfortran

version 4.4.5 (Debian 4.4.5-8) on x86_64-linux-gnu

```c The subroutine to analyze
subroutine do_something()
c For testing we just do nothing for 3 seconds
call sleep(3)
return
end

c Main Program
program timing
integer(kind=8) start,finish,rate
call system_clock(count_rate=rate)
call system_clock(start)
c Here comes the function we want to time
call do_something()
call system_clock(finish)
write(6,*) 'Elapsed Time in seconds:',float(finish-start)/rate
return
end
```

## FreeBASIC

```' FB 1.05.0 Win64

Function sumToLimit(limit As UInteger) As UInteger
Dim sum As UInteger = 0
For i As UInteger = 1 To limit
sum += i
Next
Return sum
End Function

Dim As Double start = timer
Dim limit As UInteger = 100000000
Dim result As UInteger = sumToLimit(limit)
Dim ms As UInteger = Int(1000 * (timer - start) + 0.5)
Print "sumToLimit("; Str(limit); ") = "; result
Print "took ";  ms; " milliseconds to calculate"
Print
Print "Press any key to quit"
Sleep
```
Output:
```sumToLimit(100000000) = 5000000050000000
took 314 milliseconds to calculate
```

## FutureBasic

```begin enum 1
_numLabel
_numInput
_textField
_computeTime
end enum

void local fn BuildMacInterface
window 1, @"Prime factors", ( 0, 0, 560, 120 ), NSWindowStyleMaskTitled + NSWindowStyleMaskClosable
textlabel _numLabel, @"Number to factor:", ( 155, 86, 148, 24 )
textfield _numInput, Yes, @"", ( 280, 88, 160, 24 )
TextFieldSetTextColor ( _numLabel, fn ColorGray )
ControlSetAlignment ( _numInput, NSTextAlignmentCenter )
ControlSetFormat ( _numInput, @"0123456789-", YES, 15, _formatCaseInsensitive )
ControlSetFont ( _numInput, fn FontSystemFontOfSize( 13 ) )
textfield _textField, YES, , ( 20, 46, 520, 26 )
ControlSetFontWithName ( _textField, @"Menlo", 12 )
ControlSetAlignment( _textField, NSTextAlignmentCenter )
TextFieldSetBordered( _textField, YES )
textlabel _computeTime,,( 350, 16, 188, 22 )
ControlSetAlignment( _computeTime, NSTextAlignmentRight )
WindowMakeFirstResponder ( 1, _numInput )
end fn

void local fn factor
SInt64 i, count = 0, num = fn ControlIntegerValue( _numInput ), n = num
if n < 0 then n = -n
while ( n mod 2 == 0 )
mda(count) = 2 : count++ : n = n/2
wend
for i = 3 to sqr(n) + 1 step 2
while ( n mod i == 0 )
mda(count) = i : count++ : n = n/i
wend
next
if (n > 2) then mda(count) = n
if num < 0 then mda(0) = -mda_integer(0)
CFStringRef s = fn StringByReplacingOccurrencesOfString( mda_text, @"\n", @" * " ) : mda_kill
s = fn StringByTrimmingCharactersInSet( s, fn CharacterSetWithCharactersInString( @" * " ) )
ControlSetStringValue( _textField, fn StringWithFormat( @"%@ = %lld", s, num ) )
end fn

void local fn DoDialog( ev as Long )
select ev
case _controlTextDidEndEditing
CFTimeInterval t = fn CACurrentMediaTime
fn Factor
ControlSetStringValue( _computeTime, fn StringWithFormat(  @"Compute time: %.3f ms", (fn CACurrentMediaTime-t)*1000 ) )
WindowMakeFirstResponder( _textField, _numInput )
case _windowWillClose : end
end select
end fn

fn BuildMacInterface

on dialog fn DoDialog

HandleEvents```

## GAP

```# Return the time passed in last function
time;
```

## Go

### go test

The Go command line tool `go test` includes benchmarking support. Given a package with functions:

```package empty

func Empty() {}

func Count() {
// count to a million
for i := 0; i < 1e6; i++ {
}
}
```

the following code, placed in a file whose name ends in _test.go, will time them:

```package empty

import "testing"

func BenchmarkEmpty(b *testing.B) {
for i := 0; i < b.N; i++ {
Empty()
}
}

func BenchmarkCount(b *testing.B) {
for i := 0; i < b.N; i++ {
Count()
}
}
```

`go test` varies `b.N` to get meaningful resolution. Example:

```\$ go test -bench=.
testing: warning: no tests to run
PASS
BenchmarkEmpty	2000000000	         0.30 ns/op
BenchmarkCount	   10000	    298734 ns/op
ok  		3.642s
```

The first number is the value of `b.N` chosen and the second the average time per iteration. The `testing` package can optionally include memory use and throughput benchmarks.

There is also a standard tool to compare the multiple benchmark outputs (installable via `go get golang.org/x/tools/cmd/benchcmp`).

### testing.Benchmark

The benchmarking features of the `testing` package are exported for use within a Go program.

```package main

import (
"fmt"
"testing"
)

func empty() {}

func count() {
for i := 0; i < 1e6; i++ {
}
}

func main() {
e := testing.Benchmark(func(b *testing.B) {
for i := 0; i < b.N; i++ {
empty()
}
})
c := testing.Benchmark(func(b *testing.B) {
for i := 0; i < b.N; i++ {
count()
}
})
fmt.Println("Empty function:    ", e)
fmt.Println("Count to a million:", c)
fmt.Println()
fmt.Printf("Empty: %12.4f\n", float64(e.T.Nanoseconds())/float64(e.N))
fmt.Printf("Count: %12.4f\n", float64(c.T.Nanoseconds())/float64(c.N))
}
```
Output:
```Empty function:     2000000000	         0.80 ns/op
Count to a million:     2000	    796071 ns/op

Empty:       0.7974
Count:  796071.6555
```

### Alternative technique

The `go test` command and the `testing` package are the preferred techniques for benchmarking or timing any Go code. Ignoring the well-tested and carefully crafted standard tools though, here is a simplistic alternative:

As the first line of the function you wish to time, use defer with an argument of time.Now() to print the elapsed time to the return of any function. For example, define the function from as shown below. It works because defer evaluates its function's arguments at the time the function is deferred, so the current time gets captured at the point of the defer. When the function containing the defer returns, the deferred from function runs, computes the elapsed time as a time.Duration, and prints it with standard formatting, which adds a nicely scaled unit suffix.

```package main

import (
"fmt"
"time"
)

func from(t0 time.Time) {
fmt.Println(time.Now().Sub(t0))
}

func empty() {
defer from(time.Now())
}

func count() {
defer from(time.Now())
for i := 0; i < 1e6; i++ {
}
}

func main() {
empty()
count()
}
```

Output:

```2us
643us
```

## Groovy

Translation of: Java

### CPU Timing

```import java.lang.management.ManagementFactory

def clockCpuTime = { Closure c ->
c.call()
}
```

### Wall Clock Timing

```def clockRealTime = { Closure c ->
def start = System.currentTimeMillis()
c.call()
System.currentTimeMillis() - start
}
```

Test:

```def countTo = { Long n ->
long i = 0; while(i < n) { i += 1L }
}

["CPU time":clockCpuTime, "wall clock time":clockRealTime].each { measurementType, timer ->
println '\n'
[100000000L, 1000000000L].each { testSize ->
def measuredTime = timer(countTo.curry(testSize))
println "Counting to \${testSize} takes \${measuredTime}ms of \${measurementType}"
}
}
```

Output:

```Counting to 100000000 takes 23150.5484ms of CPU time
Counting to 1000000000 takes 233861.0991ms of CPU time

Counting to 100000000 takes 24314ms of wall clock time
Counting to 1000000000 takes 249005ms of wall clock time```

## Halon

```\$t = uptime();

sleep(1);

echo uptime() - \$t;```

```import System.CPUTime (getCPUTime)

-- We assume the function we are timing is an IO monad computation
timeIt :: (Fractional c) => (a -> IO b) -> a -> IO c
timeIt action arg = do
startTime <- getCPUTime
action arg
finishTime <- getCPUTime
return \$ fromIntegral (finishTime - startTime) / 1000000000000

-- Version for use with evaluating regular non-monadic functions
timeIt_ :: (Fractional c) => (a -> b) -> a -> IO c
timeIt_ f = timeIt ((`seq` return ()) . f)
```

### Example

```*Main> :m + Text.Printf Data.List
*Main Data.List Text.Printf> timeIt' id 4 >>= printf "Identity(4) takes %f seconds.\n"
Identity(4) takes 0.0 seconds.
*Main Data.List Text.Printf> timeIt' (\x -> foldl' (+) x [1..1000000]) 4 >>= printf "Sum(4) takes %f seconds.\n"
Sum(4) takes 0.248015 seconds.
```

## HicEst

```t_start = TIME()    ! returns seconds since midnight
SYSTEM(WAIT = 1234) ! wait 1234 milliseconds
t_end = TIME()

WRITE(StatusBar) t_end - t_start, " seconds"```

## Icon and Unicon

The function 'timef' takes as argument a procedure name and collects performance and timing information including run time (in milliseconds), garbage collection, and memory usage by region.

```procedure timef(f)                               #: time a function f

every put(gcol  := [], -&collections)            # baseline collections count
every put(alloc := [], -&allocated)              # . total allocated space by region
every put(used  := [], -&storage)                # . currently used space by region - no total
every put(size  := [], -&regions)                # . current size of regions        - no total

write("Performance and Timing measurement for ",image(f),":")
runtime := &time                                 # base time
f()
write("Execution time=",&time-runtime," ms.")

every (i := 0, x := &collections) do  gcol[i +:= 1] +:= x
every (i := 0, x := &allocated  ) do alloc[i +:= 1] +:= x
every (i := 0, x := &storage    ) do  used[i +:= 1] +:= x
every (i := 0, x := &regions    ) do  size[i +:= 1] +:= x

push(gcol,"garbage collections:")
push(alloc,"memory allocated:")
push(used,"N/A","currently used:")
push(size,"N/A","current size:")

write("Memory Region and Garbage Collection Summary (delta):")
every (i := 0) <:= *!(title|gcol|alloc|used|size)
every x := (title|gcol|alloc|used|size) do {
f := left
every writes(f(!x,i + 3)) do f := right
write()
}
write("Note: static region values should be zero and may not be meaningful.")
return
end
```

Sample usage:

```procedure main()
timef(perfectnumbers)
end

procedure perfectnumbers()
...
```

Sample output (from the Perfect Numbers task):

```Performance and Timing measurement for procedure perfectnumbers:
Perfect numbers from 1 to 10000:
6
28
496
8128
Done.
Execution time=416 ms.
Memory Region and Garbage Collection Summary (delta):
total                 static                 string                  block
garbage collections:                         2                      0                      0                      2
memory allocated:                      1247012                      0                     24                1246988
currently used:                            N/A                      0                      0                 248040
current size:                              N/A                      0                      0                      0
Note: static region values should be zero and may not be meaningful.
```

## Insitux

Yes, non-transpiled Insitux really is this slow due to its original and ongoing commission: being shoehorned into a Roblox game.

```(function measure
(let [start result end] [(time) (... . args) (time)])
(str result " took " (- end start) "ms"))

(function fib n
(if (< n 2) n
(+ (fib (dec n))
(fib (- n 2)))))

(measure fib 35)
;returns "9227465 took 26497ms"```

## Ioke

```use("benchmark")

func = method((1..50000) reduce(+))

Benchmark report(1, 1, func)
```

## J

Time and space requirements are tested using verbs obtained through the Foreign conjunction (`!:`). `6!:2` returns time required for execution, in floating-point measurement of seconds. `7!:2` returns a measurement of space required to execute. Both receive as input a sentence for execution. The verb `timespacex` combines these and is available in the standard library.

There's also `timex` (which is defined as `6!:2`, but easier for some people to remember) which measures only the execution time. Interestingly, timex typically measures slightly larger times than timespacex. This is likely due to the difference between cold cache (timex) and warm cache (timespacex) -- in timespacex, the modularity of its design means that two runs of the code are performed, once to measure space use the other to measure time use.

When the Memoize feature or similar techniques are used, execution time and space can both be affected by prior calculations.

### Example

```   (6!:2 , 7!:2) '|: 50 50 50 \$ i. 50^3'      (6!:2,7!:2) '|: 50 50 50 \$ i. 50^3'
0.0014169 2.09875e6
timespacex '|: 50 50 50 \$ i. 50^3'
0.0014129 2.09875e6
timex '|: 50 50 50 \$ i. 50^3'
0.0015032
```

## Janet

```(defmacro time
"Print the time it takes to evaluate body to stderr.\n
Evaluates to body."
[body]
(with-syms [\$start \$val]
~(let [,\$start (os/clock)
,\$val ,body]
(eprint (- (os/clock) ,\$start))
,\$val)))

(time (os/sleep 0.5))
```
Output:
`0.500129`

## Java

If you're looking for a quick way to calculate the duration of a few lines of code you can utilize the `System.currentTimeMillis` method.

```long start = System.currentTimeMillis();
/* code you want to time, here */
long duration = System.currentTimeMillis() - start;
```

Works with: Java version 1.5+
```import java.lang.management.ManagementFactory;

public class TimeIt {
public static void main(String[] args) {

long start, end;
countTo(100000000);
System.out.println("Counting to 100000000 takes "+(end-start)/1000000+"ms");
countTo(1000000000L);
System.out.println("Counting to 1000000000 takes "+(end-start)/1000000+"ms");

}

public static void countTo(long x){
System.out.println("Counting...");
for(long i=0;i<x;i++);
System.out.println("Done!");
}
}
```

Measures real time rather than CPU time:

Works with: Java version (all versions)
```	public static void main(String[] args){
long start, end;
start = System.currentTimeMillis();
countTo(100000000);
end = System.currentTimeMillis();
System.out.println("Counting to 100000000 takes "+(end-start)+"ms");
start = System.currentTimeMillis();
countTo(1000000000L);
end = System.currentTimeMillis();
System.out.println("Counting to 1000000000 takes "+(end-start)+"ms");

}
```

Output:

```Counting...
Done!
Counting to 100000000 takes 370ms
Counting...
Done!
Counting to 1000000000 takes 3391ms
```

## JavaScript

```function test() {
let n = 0
for(let i = 0; i < 1000000; i++){
n += i
}
}

let start = new Date().valueOf()
test()
let end = new Date().valueOf()

console.log('test() took ' + ((end - start) / 1000) + ' seconds') // test() took 0.001 seconds
```

## Joy

```clock
1 1023 [dup +] times pop
clock swap -.```

## Julia

```# v0.6.0

function countto(n::Integer)
i = zero(n)
println("Counting...")
while i < n
i += 1
end
println("Done!")
end

@time countto(10 ^ 5)
@time countto(10 ^ 10)
```
Output:
```Counting...
Done!
Counting...
Done!
0.000109 seconds (15 allocations: 400 bytes)
Counting...
Done!
0.000127 seconds (15 allocations: 400 bytes)```

## Kotlin

Translation of: Java
```// version 1.1.2
// need to enable runtime assertions with JVM -ea option

import java.lang.management.ManagementFactory

fun countTo(x: Int) {
println("Counting...");
(1..x).forEach {}
println("Done!")
}

fun main(args: Array<String>) {
val counts = intArrayOf(100_000_000, 1_000_000_000)
for (count in counts) {
countTo(count)
println("Counting to \$count takes \${(end-start)/1000000}ms")
}
}
```

This is a typical result (sometimes the second figure is only about 1400ms - no idea why)

Output:
```Counting...
Done!
Counting to 100000000 takes 179ms
Counting...
Done!
Counting to 1000000000 takes 3527ms
```

## Lasso

```local(start = micros)
loop(100000) => {
'nothing is outout because no autocollect'
}
'time for 100,000 loop repititions: '+(micros - #start)+' microseconds'
```

## Lingo

```on testFunc ()
repeat with i = 1 to 1000000
x = sqrt(log(i))
end repeat
end```
```ms = _system.milliseconds
testFunc()
ms = _system.milliseconds - ms
put "Execution time in ms:" && ms
-- "Execution time in ms: 983"```

## Logo

Works with: UCB Logo

on a Unix system

This is not an ideal method; Logo does not expose a timer (except for the WAIT command) so we use the Unix "date" command to get a second timer.

```to time
output first first shell "|date +%s|
end
to elapsed :block
localmake "start time
run :block
(print time - :start [seconds elapsed])
end

elapsed [wait 300]   ; 5 seconds elapsed```

## Lua

```function Test_Function()
for i = 1, 10000000 do
local s = math.log( i )
s = math.sqrt( s )
end
end

t1 = os.clock()
Test_Function()
t2 = os.clock()

print( os.difftime( t2, t1 ) )
```

## M2000 Interpreter

We use Profiler to reset timer, and Timecount to read time in milliseconds as a double, with nanoseconds for resolution. Internal use of QueryPerformanceCounter from Windows Api. In this example we get times for use of same module with different variable types. sum=limit-limit make sum 0 to the same type of limit,and using n=sum and n++ we make n=1 using same type as sum.

10000% is Integer 16bit

10000& is Long 32bit

10000@ is Decimal

10000# is Currency

10000~ is Float

10000 is Double (default)

10000&& is long long (64bit integer)

255ub is Byte type (unsigned value, 0 to 255)

Although parameter limit take the type Byte from the argument passed, the limit-limit converted to integer, so sum and n get type integer, so the loop use integers 16bit. So we use the sumtolimit2. The n-! change sign, and this cause overflow for byte value, so this removed from the sumtolimit2.

Function/Module Parameters in M2000 without explicitly assign type take the type from stack of values which a Read statement (which Interpreter insert to code) read from there. This type can't change for the run of module or function. We can define a parameter as variant if we want to allow changes of the type.

```Module Checkit {
Module sumtolimit (limit) {
sum=limit-limit
n=sum
rem print type\$(n), type\$(sum), type\$(limit)
n++
while limit {sum+=limit*n:limit--:n-!}
}
Module sumtolimit2 (limit) {
byte sum, n
n++
while limit {sum++:limit--}
}
Cls ' clear screen
Profiler
sumtolimit 10000%
Print TimeCount
Profiler
sumtolimit 10000&
Print TimeCount
Profiler
sumtolimit 10000#
Print TimeCount
Profiler
sumtolimit 10000@
Print TimeCount
Profiler
sumtolimit 10000~
Print TimeCount
Profiler
sumtolimit 10000
Print TimeCount
Profiler
sumtolimit 10000&&
Print TimeCount
Profiler
sumtolimit 255ub
Print TimeCount
Profiler
sumtolimit2 255ub
Print TimeCount
}
Checkit```

## Maple

The built-in command CodeTools:-Usage can compute the "real" time for the length of the computation or the "cpu" time for the computation. The following examples find the real time and cpu time for computing the integer factors for 32!+1.

`CodeTools:-Usage(ifactor(32!+1), output = realtime, quiet);`
`CodeTools:-Usage(ifactor(32!+1), output = cputime, quiet);`

## Mathematica /Wolfram Language

```AbsoluteTiming[x];
```

where x is an operation. Example calculating a million digits of Sqrt[3]:

```AbsoluteTiming[N[Sqrt[3], 10^6]]
```
Output:
```{0.000657, 1.7320508075688772935274463......}
```

First elements if the time in seconds, second elements if the result from the operation. Note that I truncated the result.

## Maxima

```f(n) := if n < 2 then n else f(n - 1) + f(n - 2)\$

/* First solution, call the time function with an output line number, it gives the time taken to compute that line.
Here it's assumed to be %o2 */
f(24);
46368

time(%o2);
[0.99]

/* Second solution, change a system flag to print timings for all following lines */
showtime: true\$

f(24);
Evaluation took 0.9400 seconds (0.9400 elapsed)
46368
```

## MiniScript

```start = time
for i in range(1,100000)
end for
duration = time - start
print "Process took " + duration + " seconds"
```
Output:
```Process took 0.312109 seconds
```

## Nim

```import times, strutils

proc doWork(x: int) =
var n = x
for i in 0..10000000:
n += i

template time(statement: untyped): float =
let t0 = cpuTime()
statement
cpuTime() - t0

echo "Time = ", time(doWork(100)).formatFloat(ffDecimal, precision = 3), " s"
```
Output:

Compiled in debug mode (no options).

`Time = 0.046 s`

## Nu

`timeit { sleep 1ms }`
Output (example):
`1ms 112µs 723ns`

## OCaml

```let time_it action arg =
let start_time = Sys.time () in
ignore (action arg);
let finish_time = Sys.time () in
finish_time -. start_time
```

### Example

```# Printf.printf "Identity(4) takes %f seconds.\n" (time_it (fun x -> x) 4);;
Identity(4) takes 0.000000 seconds.
- : unit = ()
# let sum x = let num = ref x in for i = 0 to 999999 do num := !num + i done; !num;;
val sum : int -> int = <fun>
# Printf.printf "Sum(4) takes %f seconds.\n" (time_it sum 4);;
Sum(4) takes 0.084005 seconds.
- : unit = ()
```

## Oforth

bench allows to calculate how long a runnable takes to execute.

Result is microseconds.

It uses difference between system time, not processing time.

Output:
```>#[ 0 1000 seq apply(#+) ] bench .
267
500500 ok
```

## Oz

```declare
%% returns milliseconds
fun {TimeIt Proc}
Before = {Now}
in
{Proc}
{Now} - Before
end

fun {Now}
{Property.get 'time.total'}
end
in
{Show
{TimeIt
proc {\$}
{FoldL {List.number 1 1000000 1} Number.'+' 4 _}
end}
}```

## PARI/GP

This version, by default, returns just the CPU time used by gp, not the delta of wall times. PARI can be compiled to use wall time if you prefer: configure with `--time=ftime` instead of ```--time= getrusage```, `--time=clock_gettime`, or `--time=times`. See Appendix A, section 2.2 of the User's Guide to PARI/GP.

```time(foo)={
foo();
gettime();
}```

Alternate version:

Works with: PARI/GP version 2.6.2+
```time(foo)={
my(start=getabstime());
foo();
getabstime()-start;
}```

## PascalABC.NET

```function LongTimeCalc(n: integer): real;
begin
var sum := 0.0;
for var i:=1 to n do
for var j := 1 to n do
sum += 1/i/j;
Result := sum;
end;

begin
MillisecondsDelta;
LongTimeCalc(10000).Println;
MillisecondsDelta.Println;
end.
```

## Perl

Example of using the built-in Benchmark core module - it compares two versions of recursive factorial functions:

```use Benchmark;
use Memoize;

sub fac1 {
my \$n = shift;
return \$n == 0 ? 1 : \$n * fac1(\$n - 1);
}
sub fac2 {
my \$n = shift;
return \$n == 0 ? 1 : \$n * fac2(\$n - 1);
}
memoize('fac2');

my \$result = timethese(100000, {
'fac1' => sub { fac1(50) },
'fac2' => sub { fac2(50) },
});
Benchmark::cmpthese(\$result);
```

Output:

```Benchmark: timing 100000 iterations of fac1, fac2...
fac1:  6 wallclock secs ( 5.45 usr +  0.00 sys =  5.45 CPU) @ 18348.62/s (n=100000)
fac2:  1 wallclock secs ( 0.84 usr +  0.00 sys =  0.84 CPU) @ 119047.62/s (n=100000)
Rate fac1 fac2
fac1  18349/s   -- -85%
fac2 119048/s 549%   --
```

Example without using Benchmark:

```sub cpu_time {
my (\$user,\$system,\$cuser,\$csystem) = times;
\$user + \$system
}

sub time_it {
my \$action = shift;
my \$startTime = cpu_time();
\$action->(@_);
my \$finishTime = cpu_time();
\$finishTime - \$startTime
}

printf "Identity(4) takes %f seconds.\n", time_it(sub {@_}, 4);
# outputs "Identity(4) takes 0.000000 seconds."

sub sum {
my \$x = shift;
foreach (0 .. 999999) {
\$x += \$_;
}
\$x
}

printf "Sum(4) takes %f seconds.\n", time_it(\&sum, 4);
# outputs "Sum(4) takes 0.280000 seconds."
```

## Phix

Library: Phix/basics

Measures wall-clock time. On Windows the resolution is about 15ms. The elapsed function makes it more human-readable, eg elapsed(720) yields "12 minutes".

```with javascript_semantics
function identity(integer x)
return x
end function

function total(integer num)
for i=1 to 100_000_000 do
num += odd(i)
end for
return num
end function

procedure time_it(integer fn)
atom t0 = time()
integer res = fn(4)
string funcname = get_routine_info(fn)[4]
printf(1,"%s(4) = %d, taking %s\n",{funcname,res,elapsed(time()-t0)})
end procedure

time_it(identity)
time_it(total)
```
Output:
```identity(4) = 4, taking 0s
total(4) = 50000004, taking 6.8s
```

## Phixmonti

```def count
for drop endfor
enddef

1000000 count
msec dup var t0 print " seconds" print nl

10000000 count
msec t0 - print " seconds" print```

## Picat

Picat had some built-in timing functions/predicates:

• `time/1`: reports the time since start of execution. (The related `time2/1` also reports the backtracks for CP problems.)
• `statistics(runtime,[ProgTime,LastTime])`: `ProgTime` is the ms since program started, `LastTime` is the ms since last call to `statistics(runtime,_)`. It can be used to create user defined time predicates/functions, as show in `time1b/1`.
```import cp.

go =>
println("time/1 for 201 queens:"),
time2(once(queens(201,_Q))),
nl,

% time1b/1 is a used defined function (using statistics/2)
Time = time1b(\$once(queens(28,Q2))),
println(Q2),
printf("28-queens took %dms\n", Time),
nl.

% N-queens problem.
% N: number of queens to place
% Q: the solution
queens(N, Q) =>
Q=new_list(N),
Q :: 1..N,
all_different(Q),
all_different([\$Q[I]-I : I in 1..N]),
all_different([\$Q[I]+I : I in 1..N]),
solve([ffd,split],Q).

% time1b/1 is a function that returns the time (ms)
time1b(Goal) = T =>
statistics(runtime, _),
call(Goal),
statistics(runtime, [_,T]).```
Output:
```time/1 for 201 queens:
CPU time 0.049 seconds. Backtracks: 0

[1,3,5,23,13,4,21,7,14,26,24,19,6,20,18,28,8,27,2,10,25,17,9,16,12,15,11,22]
28-queens took 0ms```

## PicoLisp

There is a built-in function 'bench' for that. However, it measures wall-clock time, because for practical purposes the real time needed by a task (including I/O and communication) is more meaningful. There is another function, 'tick', which also measures user time, and is used by the profiling tools.

```: (bench (do 1000000 (* 3 4)))
0.080 sec
-> 12```

## Pike

Shows CPU time used, not including any automatic gc passes. Explicit calls to gc() are included though. This example uses the convenience function gauge(), but it could also be done manually with gethrvtime() in ms or ns resolution.

```void get_some_primes()
{
int i;
while(i < 10000)
i = i->next_prime();
}

void main()
{
float time_wasted = gauge( get_some_primes() );
write("Wasted %f CPU seconds calculating primes\n", time_wasted);
}
```
Output:
```Wasted 0.014 CPU seconds calculating primes
```

## PL/I

```declare (start_time, finish_time) float (18);

start_time = secs();

do i = 1 to 10000000;
/* something to be repeated goes here. */
end;
finish_time = secs();

put skip edit ('elapsed time=', finish_time - start_time, ' seconds')
(A, F(10,3), A);
/* gives the result to thousandths of a second. */

/* Note: using the SECS function takes into account the clock */
/* going past midnight. */```

## PowerShell

```function fun(\$n){
\$res = 0
if(\$n -gt 0) {
1..\$n | foreach{
\$a, \$b = \$_, (\$n+\$_)
\$res += \$a + \$b
}

}
\$res
}
"\$((Measure-Command {fun 10000}).TotalSeconds) Seconds"
```

Output:

```0.820712 Seconds
```

## PureBasic

### Built in timer

This version uses the built in timer, on Windows it has an accuracy of ~10-15 msec.

```Procedure Foo(Limit)
Protected i, palindromic, String\$
For i=0 To Limit
String\$=Str(i)
If String\$=ReverseString(String\$)
palindromic+1
EndIf
Next
ProcedureReturn palindromic
EndProcedure

If OpenConsole()
Define Start, Stop, cnt
PrintN("Starting timing of a calculation,")
PrintN("for this we test how many of 0-1000000 are palindromic.")
Start=ElapsedMilliseconds()
cnt=Foo(1000000)
Stop=ElapsedMilliseconds()
PrintN("The function need "+Str(stop-Start)+" msec,")
PrintN("and "+Str(cnt)+" are palindromic.")
Print("Press ENTER to exit."): Input()
EndIf
```
```Starting timing of a calculation,
for this we test how many of 0-1000000 are palindromic.
The function need 577 msec,
and 1999 are palindromic.
Press ENTER to exit.
```

### Hi-res version

Library: Droopy

This version uses a hi-res timer, but it is Windows only.

```If OpenConsole()
Define Timed.f, cnt
PrintN("Starting timing of a calculation,")
PrintN("for this we test how many of 0-1000000 are palindromic.")
; Dependent on Droopy-library
If MeasureHiResIntervalStart()
; Same Foo() as above...
cnt=Foo(1000000)
Timed=MeasureHiResIntervalStop()
EndIf
PrintN("The function need "+StrF(Timed*1000,3)+" msec,")
PrintN("and "+Str(cnt)+" are palindromic.")
Print("Press ENTER to exit."): Input()
EndIf
```
```Starting timing of a calculation,
for this we test how many of 0-1000000 are palindromic.
The function need 604.341 msec,
and 1999 are palindromic.
Press ENTER to exit.
```

This version still relies on the Windows API but does not make use of any additional libraries.

```Procedure.f ticksHQ(reportIfPresent = #False)
Static maxfreq.q
Protected T.q
If reportIfPresent Or maxfreq = 0
QueryPerformanceFrequency_(@maxfreq)
If maxfreq
ProcedureReturn 1.0
Else
ProcedureReturn 0
EndIf
EndIf
QueryPerformanceCounter_(@T)
ProcedureReturn T / maxfreq ;Result is in milliseconds
EndProcedure

If OpenConsole()
Define timed.f, cnt
PrintN("Starting timing of a calculation,")
PrintN("for this we test how many of 0-1000000 are palindromic.")
; Dependent on Windows API
If ticksHQ(#True)
timed = ticksHQ() ;start time
; Same Foo() as above...
cnt = Foo(1000000)
timed = ticksHQ() - timed ;difference
EndIf
PrintN("The function need " + StrF(timed * 1000, 3) + " msec,")
PrintN("and " + Str(cnt) + " are palindromic.")
Print("Press ENTER to exit."): Input()
EndIf
```

Sample output:

```Starting timing of a calculation,
for this we test how many of 0-1000000 are palindromic.
The function need 174.811 msec,
and 1999 are palindromic.
```

## Python

Given function and arguments return a time (in microseconds) it takes to make the call.

Note: There is an overhead in executing a function that does nothing.

```import sys, timeit
def usec(function, arguments):
modname, funcname = __name__, function.__name__
timer = timeit.Timer(stmt='%(funcname)s(*args)' % vars(),
setup='from %(modname)s import %(funcname)s; args=%(arguments)r' % vars())
try:
t, N = 0, 1
while t < 0.2:
t = min(timer.repeat(repeat=3, number=N))
N *= 10
microseconds = round(10000000 * t / N, 1) # per loop
return microseconds
except:
timer.print_exc(file=sys.stderr)
raise

from math import pow
def nothing(): pass
def identity(x): return x
```

### Example

```>>> print(usec(nothing, []))
1.7
>>> print(usec(identity, [1]))
2.2
>>> print(usec(pow, (2, 100)))
3.3
>>> print([usec(qsort, (range(n),)) for n in range(10)])
[2.7, 2.8, 31.4, 38.1, 58.0, 76.2, 100.5, 130.0, 149.3, 180.0]
```

using qsort() from Quicksort. Timings show that the implementation of qsort() has quadratic dependence on sequence length N for already sorted sequences (instead of O(N*log(N)) in average).

## Quackery

`time` returns system time since Unix epoch in microseconds, but is not reliable to the microsecond, so we are using millisecond granularity. Process time is not available.

```  [ time ]'[ do
time swap - 1000 / ] is time: ( --> n )

time: [ 0 314159 times 1+ echo ]
cr cr
say "That took about " echo say " milliseconds."```
Output:
```314159

```

## R

R has a built-in function, system.time, to calculate this.

```# A task
foo <- function()
{
for(i in 1:10)
{
mat <- matrix(rnorm(1e6), nrow=1e3)
mat^-0.5
}
}
timer <- system.time(foo())
# Extract the processing time
timer["user.self"]
```

For a breakdown of processing time by function, there is Rprof.

```Rprof()
foo()
Rprof(NULL)
summaryRprof()
```

## Racket

```#lang racket
(define (fact n) (if (zero? n) 1 (* n (fact (sub1 n)))))
(time (fact 5000))
```

## Raku

(formerly Perl 6) Follows modern trend toward measuring wall-clock time, since CPU time is becoming rather ill-defined in the age of multicore, and doesn't reflect IO overhead in any case.

```my \$start = now;
(^100000).pick(1000);
say now - \$start;
```
Output:
`0.02301709`

## Raven

```define doId use \$x
\$x dup * \$x /

define doPower use \$v, \$p
\$v \$p pow

define doSort
group
20000 each choose
list sort reverse

define timeFunc use \$fName
time as \$t1
\$fName "" prefer call
time as \$t2
\$fName \$t2 \$t1 -"%.4g secs for %s\n" print

"NULL" timeFunc
42 "doId" timeFunc
12 2 "doPower" timeFunc
"doSort" timeFunc```
Output:
```2.193e-05 secs for NULL
2.003e-05 secs for doId
4.601e-05 secs for doPower
3.028 secs for doSort```

## Retro

Retro has a time function returning the current time in seconds. This can be used to build a simple timing function:

```: .runtime ( a- ) time [ do time ] dip - "\n%d\n" puts ;

: test 20000 [ putn space ] iterd ;
&test .runtime```

Finer measurements are not possible with the standard implementation.

## REXX

### elapsed time version

REXX doesn't have a language feature for obtaining true CPU time (except under
IBM mainframes which have commands that can retrieve such times), but it does
have a built-in function for elapsed time(s).

On my machine, I found the granularity of Regina always to be 0.001s. For ooRexx it was mostly 0.015s, but I also observed 0.004s.
Run following small program to find the granularity of your system's clock.

```do x = 1 to 40
say time('l') time('e')
do y = 1 to 10000
end
end
```

The main reason for the true CPU time omission is that REXX was developed under VM/CMS and
there's a way to easily query the host (VM/CP) to indicate how much   true   CPU time was used by
(normally) your own userID.  The result can then be placed into a REXX variable (as an option).

```/*REXX program displays the elapsed time for a REXX function (or subroutine). */
arg reps .                             /*obtain an optional argument from C.L.*/
if reps==''  then reps=100000          /*Not specified?  No, then use default.*/
call time 'Reset'                      /*only the 1st character is examined.  */
junk = silly(reps)                     /*invoke the  SILLY  function (below). */
/*───►   CALL SILLY REPS    also works.*/

/*                          The    E   is for    elapsed    time.*/
/*                                 │             ─               */
/*                        ┌────◄───┘                             */
/*                        │                                      */
/*                        ↓                                      */
say 'function SILLY took' format(time("E"),,2)  'seconds for' reps "iterations."
/*                             ↑                                 */
/*                             │                                 */
/*            ┌────────►───────┘                                 */
/*            │                                                  */
/* The above  2  for the  FORMAT  function displays the time with*/
/* two decimal digits (rounded)  past the decimal point).  Using */
/* a   0  (zero)    would round the  time  to whole seconds.     */
exit                                   /*stick a fork in it,  we're all done. */
/*────────────────────────────────────────────────────────────────────────────*/
silly: procedure               /*chew up some CPU time doing some silly stuff.*/
do j=1  for arg(1) /*wash,  apply,  lather,  rinse,  repeat.  ··· */
@.j=random() date() time() digits() fuzz() form() xrange() queued()
end   /*j*/
return j-1
```

output   when using a personal computer built in the 20th century:

```function SILLY took 3.54 seconds for 100000 iterations.
```

output   when using a personal computer built in the 21st century:

```function SILLY took 0.44 seconds for 100000 iterations.
```

output   when using an IBM mainframe with MVS/TSO:

```function SILLY took 0.69 seconds for 100000 iterations.
```

### CPU time used version

This version   only   works with Regina REXX as the   J   option   (for the time BIF)   is a Regina extension.

Since the   silly   function (by far) consumes the bulk of the CPU time of the REXX program, what is
being measured is essentially the same as the wall clock time (duration) of the function execution;   the
overhead of the invocation is minimal compared to the overall time used.

```/*REXX program displays the elapsed time for a REXX function (or subroutine). */
arg reps .                             /*obtain an optional argument from C.L.*/
if reps==''  then reps=100000          /*Not specified?  No, then use default.*/
call time 'Reset'                      /*only the 1st character is examined.  */
junk = silly(reps)                     /*invoke the  SILLY  function (below). */
/*───►   CALL SILLY REPS    also works.*/

/*                          The   J   is for the CPU time used   */
/*                                │   by the REXX program since  */
/*                        ┌───────┘   since the time was  RESET. */
/*                        │           This is a Regina extension.*/
/*                        ↓                                      */
say 'function SILLY took' format(time("J"),,2)  'seconds for' reps "iterations."
/*                             ↑                                 */
/*                             │                                 */
/*            ┌────────►───────┘                                 */
/*            │                                                  */
/* The above  2  for the  FORMAT  function displays the time with*/
/* two decimal digits (rounded)  past the decimal point).  Using */
/* a   0  (zero)    would round the  time  to whole seconds.     */
exit                                   /*stick a fork in it,  we're all done. */
/*────────────────────────────────────────────────────────────────────────────*/
silly: procedure               /*chew up some CPU time doing some silly stuff.*/
do j=1  for arg(1) /*wash,  apply,  lather,  rinse,  repeat.  ··· */
@.j=random() date() time() digits() fuzz() form() xrange() queued()
end   /*j*/
return j-1
```

output   is essentially identical to the previous examples.

### Performance comparison

It's not very meaningful to compare performance of different languages. But with ANSI compatible REXXen you may exactly run the same program on the same machine. I did this for Regina and ooRexx.
Running Mike Cowlishaw's famous RexxCps program, version 2.2, gives on Intel i7, 4.5Ghz, 16GB, Windows 11 following output. All timings are elapsed time.

Output:
```----- REXXCPS 2.2 -- Measuring REXX clauses/second -----
REXX version: REXX-Regina_3.9.6(MT) 5.00 29 Apr 2024
System: WIN64

Averaging: 100 measures of 1000 iterations
Total iterations: 0.1 million
Total clauses: 100 million

Calibration begin: 55314.874
Calibration einde: 55314.874 took 0 secs
Calibration (empty DO): 0 secs (average of 100)

True run begin: 55314.874
True run einde: 55320.604 took 5.730 secs

Total (full DO): 0.0573 secs (average of 100 measures of 1000 iterations)
Time for one iteration (1000 clauses) was: 0.0000573 seconds

Performance: 17.452007 million REXX clauses per second

----- REXXCPS 2.2 -- Measuring REXX clauses/second -----
REXX version: REXX-ooRexx_5.0.0(MT)_64-bit 6.05 23 Dec 2022
System: WindowsNT

Averaging: 100 measures of 1000 iterations
Total iterations: 0.1 million
Total clauses: 100 million

Calibration begin: 55328.934
Calibration einde: 55328.934 took 0 secs
Calibration (empty DO): 0 secs (average of 100)

True run begin: 55328.934
True run einde: 55334.512 took 5.578 secs

Total (full DO): 0.05578 secs (average of 100 measures of 1000 iterations)
Time for one iteration (1000 clauses) was: 0.00005578 seconds

Performance: 17.9275726 million REXX clauses per second
```

That's about equal. However, I wondered if the two versions differ in the performance of their elementary operations, such as assignments, looping, calculations, IO and more. The following program is an attempt to measure it.

```Main:
call Parameters
call DoToLoops
call DoForLoops
call Tarra
call IntegerAssign
call IntegerSubtract
call IntegerMultiply
call IntegerDivide1
call IntegerDivide2
call IntegerRemainder
call IntegerPower
call FloatingAssign
call FloatingSubtract
call FloatingMultiply
call FloatingDivide1
call FloatingDivide2
call FloatingRemainder
call FloatingPower
call Formula
call StringFunctions
call NumericFunctions
call FixedParseVar
call DynamicParseVar
call NoOperation
call IfThen
call SelectWhen
call IfElseIf
call CallProc
call CallProcParms
call CallRout
call CallRoutParms
call DateTime
call PushPullQueued
call Interpreting
call Output
call Input
call StemProcessing
return

Parameters:
arg count digit
if count = '' then
count = 1e6
if digit = '' then
digit = 9
numeric digits digit
parse version version
say 'Version' version
say 'Using loop counter' count/1e6 'million and' digits() 'digits'
say
tarra = 0
call time('r')
return

DoToLoops:
call time('r')
do x = 1 to count*10
end
call Measure 'Do ... to ...',10
return

DoForLoops:
call time('r')
do x = 1 for count*10
end
call Measure 'Do ... for ...',10
return

Tarra:
call time('r')
do x = 1 to count*10
end
tarra = time('e')/10
return

IntegerAssign:
call time('r')
do x = 1 to count*10
a = 123
end
call Measure 'Integer assign',10
return

call time('r')
do x = 1 to count*10
a = x+123
end
call Measure 'Integer +',10
return

IntegerSubtract:
call time('r')
do x = 1 to count*10
a = x-123
end
call Measure 'Integer -',10
return

IntegerMultiply:
call time('r')
do x = 1 to count*10
a = x*123
end
call Measure 'Integer *',10
return

IntegerDivide1:
call time('r')
do x = 1 to count*10
a = 123/3
end
call Measure 'Integer /',10
return

IntegerDivide2:
call time('r')
do x = 1 to count*10
a = x//123
end
call Measure 'Integer //',10
return

IntegerRemainder:
call time('r')
do x = 1 to count*10
a = x%123
end
call Measure 'Integer %',10
return

IntegerPower:
call time('r')
do x = 1 to count*10
a = 123**2
end
call Measure 'Integer **',10
return

FloatingAssign:
call time('r')
do x = 1 to count*10
a = 1.23
end
call Measure 'Floating assign',10
return

call time('r')
do x = 1 to count*10
a = x+1.23
end
call Measure 'Floating +',10
return

FloatingSubtract:
call time('r')
do x = 1 to count*10
a = x-1.23
end
call Measure 'Floating -',10
return

FloatingMultiply:
call time('r')
do x = 1 to count*10
a = x*1.23
end
call Measure 'Floating *',10
return

FloatingDivide1:
call time('r')
do x = 1 to count*10
a = x/1.23
end
call Measure 'Floating /',10
return

FloatingDivide2:
call time('r')
do x = 1 to count*10
a = x//1.23
end
call Measure 'Floating //',10
return

FloatingRemainder:
call time('r')
do x = 1 to count*10
a = x%1.23
end
call Measure 'Floating %',10
return

FloatingPower:
call time('r')
do x = 1 to count*10
a = 1.23**2
end
call Measure 'Floating **',10
return

Formula:
call time('r')
do x = 1 to count
a = ( (x+1.23) * (x-1.23) ) / ( (x*1.23) * (x/1.23) )
end
call Measure 'Formula',1
return

StringFunctions:
a = 'this is the first text'; b = 'this is the second text'; c = 1.23
call time('r')
do x = 1 to count
t = a||b
t = abbrev('text',a)
t = center(a,100)
t = compare(a,b)
t = copies(a,3)
t = delstr(a,5,10)
t = delword(a,2,3)
t = format(c,1,2)
t = insert(a,b,10)
t = lastpos('text',a)
t = left(a,10)
t = length(a)
t = overlay('paul',a,4)
t = pos('text',a)
t = reverse(a)
t = right(a,10)
t = space(a)
t = strip(a)
t = substr(a,5,10)
t = subword(a,2,2)
t = translate(a,'one','the')
t = verify(a,'the')
t = word(a,3)
t = wordindex(a,3)
t = wordlength(a,3)
t = wordpos('is the',a)
t = words(a)
t = xrange('a','z')
end
call Measure 'String functions',28
return

NumericFunctions:
a = -1.23; b = 1.23
call time('r')
do x = 1 to count
t = abs(a)
t = max(a,b)
t = min(a,b)
t = random()
t = sign(a)
t = trunc(b)
t = digits()
end
call Measure 'Numeric functions',7
return

FixedParseVar:
t = '1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20'
call time('r')
do x = 1 to count
parse var t rec1 ','  rec2 ','  rec3 ','  rec4 ','  rec5 ','  rec6 ','  rec7 ','  rec8 ','  rec9 ','  rec10 ',',
rec11 ',' rec12 ',' rec13 ',' rec14 ',' rec15 ',' rec16 ',' rec17 ',' rec18 ',' rec19 ',' rec20 ','
end
call Measure 'Fixed parse var',1
return

DynamicParseVar:
t = '1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20'
call time('r')
do x = 1 to count
do y = 1 to 20
parse var t rec.y ',' t
end
end
call Measure 'Dynamic parse var',1
return

NoOperation:
call time('r')
do x = 1 to count*10
nop
end
call Measure 'No operation',10
return

IfThen:
a = 1
call time('r')
do x = 1 to count
if a = 1 then nop
if a = 2 then nop
if a <> 1 then nop
if a <> 2 then nop
if a < 0 then nop
if a < 2 then nop
if a > 0 then nop
if a > 2 then nop
end
call Measure 'If ...then ...',8
return

SelectWhen:
a = 2
call time('r')
do x = 1 to count
select
when a = 1 then nop
when a = 2 then nop
when a = 3 then nop
end
select
when a <> 2 then nop
when a <> 1 then nop
when a <> 0 then nop
end
select
when a > 2 then nop
when a > 1 then nop
when a > 0 then nop
end
select
when a < 2 then nop
when a < 3 then nop
when a < 4 then nop
end
end
call Measure 'Select ... when ...',8
return

IfElseIf:
a = 2
call time('r')
do x = 1 to count
if a = 1 then nop
else if a = 2 then nop
else if a = 3 then nop
if a <> 2 then nop
else if a <> 1 then nop
else if a <> 0 then nop
if a > 2 then nop
else if a > 1 then nop
else if a > 0 then nop
if a < 2 then nop
else if a < 3 then nop
else if a < 4 then nop
end
call Measure 'If ... else if ...',8
return

CallProc:
call time('r')
do x = 1 to count
call Proc1
end
call Measure 'Call procedure',1
return

CallProcParms:
call time('r')
do x = 1 to count
call Proc2 1,2,3
end
call Measure 'Call procedure with parms',1
return

CallRout:
call time('r')
do x = 1 to count
call Rout1
end
call Measure 'Call routine',1
return

CallRoutParms:
call time('r')
do x = 1 to count
call Rout2 1,2,3
end
call Measure 'Call routine with parms',1
return

Proc1:
procedure
return

Proc2:
procedure
arg a,b,c
return

Rout1:
return

Rout2:
arg a,b,c
return

DateTime:
call time('r')
do x = 1 to count
t = date('b')
t = date('d')
t = date('e')
t = date('m')
t = date('n')
t = date('o')
t = date('s')
t = date('u')
t = date('w')
t = time('c')
t = time('e')
t = time('h')
t = time('l')
t = time('m')
t = time('n')
t = time('s')
end
call Measure 'Date and time',16
return

PushPullQueued:
a = 123.45
call time('r')
do x = 1 to count
push a
b = queued()
pull a
end
call Measure 'Push, pull and queued',3
return

Interpreting:
a = 'nop'
call time('r')
do x = 1 to count
interpret a
end
call Measure 'Interpret',1
return

Output:
file = '\temp\perf.txt'
call lineout file,,1
call time('r')
do x = 1 to count
call lineout file,'sequence number of this record is' x
end
call Measure 'Output',1
return

Input:
file = '\temp\perf.txt'
call time('r')
do x = 1 to count
t = linein(file)
end
call Measure 'Input',1
return

StemProcessing:
call time('r')
do x = 1 to count
stem.x.x.x = 1.23
end
call Measure 'Stem processing',1
return

Measure:
parse arg measure,clauses
elaps = time('e')-tarra
if elaps > 0 then do
say left(measure,25) format((count*clauses)/(1e6*elaps) ,3,1) 'million clauses/sec'
end
else
say left(measure,25) 'loop counter too low, cannot perform measure'
return
```
Output:
```Version REXX-Regina_3.9.6(MT) 5.00 29 Apr 2024
Using loop counter 1 million and 9 digits

Do ... to ...              70.4 million clauses/sec
Do ... for ...             93.5 million clauses/sec
Integer assign             25.0 million clauses/sec
Integer +                  11.0 million clauses/sec
Integer -                  11.4 million clauses/sec
Integer *                   6.4 million clauses/sec
Integer /                   9.5 million clauses/sec
Integer //                  3.5 million clauses/sec
Integer %                   4.0 million clauses/sec
Integer **                  5.1 million clauses/sec
Floating assign            25.7 million clauses/sec
Floating +                 10.6 million clauses/sec
Floating -                 10.8 million clauses/sec
Floating *                  6.4 million clauses/sec
Floating /                  2.4 million clauses/sec
Floating //                 3.0 million clauses/sec
Floating %                  3.1 million clauses/sec
Floating **                 5.2 million clauses/sec
Formula                     0.4 million clauses/sec
String functions            9.1 million clauses/sec
Numeric functions           9.2 million clauses/sec
Fixed parse var             2.3 million clauses/sec
Dynamic parse var           0.4 million clauses/sec
No operation               37.5 million clauses/sec
If ...then ...             40.7 million clauses/sec
Select ... when ...        38.3 million clauses/sec
If ... else if ...         37.8 million clauses/sec
Call procedure              3.3 million clauses/sec
Call procedure with parms   2.0 million clauses/sec
Call routine                6.4 million clauses/sec
Call routine with parms     4.1 million clauses/sec
Date and time               1.6 million clauses/sec
Push, pull and queued      21.8 million clauses/sec
Interpret                   1.2 million clauses/sec
Output                      0.2 million clauses/sec
Input                       0.3 million clauses/sec
Stem processing             4.0 million clauses/sec

Version REXX-ooRexx_5.0.0(MT)_64-bit 6.05 23 Dec 2022
Using loop counter 1 million and 9 digits

Do ... to ...              27.9 million clauses/sec
Do ... for ...             30.4 million clauses/sec
Integer assign             27.0 million clauses/sec
Integer +                  17.4 million clauses/sec
Integer -                  16.5 million clauses/sec
Integer *                  11.5 million clauses/sec
Integer /                  20.2 million clauses/sec
Integer //                 18.0 million clauses/sec
Integer %                  15.3 million clauses/sec
Integer **                 15.4 million clauses/sec
Floating assign            27.0 million clauses/sec
Floating +                  8.1 million clauses/sec
Floating -                  7.5 million clauses/sec
Floating *                  6.2 million clauses/sec
Floating /                  2.7 million clauses/sec
Floating //                 3.4 million clauses/sec
Floating %                  3.5 million clauses/sec
Floating **                 5.6 million clauses/sec
Formula                     0.9 million clauses/sec
String functions           14.9 million clauses/sec
Numeric functions          14.1 million clauses/sec
Fixed parse var             1.2 million clauses/sec
Dynamic parse var           0.4 million clauses/sec
No operation               29.5 million clauses/sec
If ...then ...             47.9 million clauses/sec
Select ... when ...        28.9 million clauses/sec
If ... else if ...         40.4 million clauses/sec
Call procedure              5.9 million clauses/sec
Call procedure with parms   3.1 million clauses/sec
Call routine                7.3 million clauses/sec
Call routine with parms     4.3 million clauses/sec
Date and time               3.9 million clauses/sec
Push, pull and queued       0.1 million clauses/sec
Interpret                   0.3 million clauses/sec
Output                      0.8 million clauses/sec
Input                       0.4 million clauses/sec
Stem processing             2.3 million clauses/sec
```

Regina wins Loop processing, Parse pull queued, Stem processing.
ooRexx wins Integer calculations, String and numeric functions, Formula, IO.

## Ring

```beginTime = TimeList()[13]
for n = 1 to 10000000
n = n + 1
next
endTime = TimeList()[13]
elapsedTime = endTime - beginTime
see "Elapsed time = " + elapsedTime + nl```

## RPL

In its first versions, RPL did not provide user access to system clock - but advanced users knew which system call can be made on their machine to get it. The following code works on a 1987-manufactured HP-28S, but can crash on older ones and will surely do on other machines. If using a newer model, replace `#11CAh SYSEVAL` by `TICKS`, which is a (safe) built-in instruction.

RPL code Comment
```≪
#11CAh SYSEVAL → tick
≪ EVAL
#11CAh SYSEVAL tick -
B→R 8192 / 1 FIX RND STD
≫ ≫ 'TEVAL' STO
```
``` TEVAL ( ≪function≫  -- execution_time )
Store current system time
Execute function
Measure difference in CPU cycles
convert to seconds, round to one decimal place

```
Input:
```≪ 1 1000 START NEXT ≫ TEVAL
```
Output:
```1: 6.4
```

Yes, more than 6 seconds to loop 1000 times is quite slow.

HP-49+ models have a built-in `TEVAL` command.

## Ruby

Ruby's Benchmark module provides a way to generate nice reports (numbers are in seconds):

```require 'benchmark'

Benchmark.bm(8) do |x|
x.report("nothing:")  {  }
x.report("sum:")  { (1..1_000_000).inject(4) {|sum, x| sum + x} }
end
```

Output:

```              user     system      total        real
nothing:  0.000000   0.000000   0.000000 (  0.000014)
sum:      2.700000   0.400000   3.100000 (  3.258348)
```

You can get the total time as a number for later processing like this:

```Benchmark.measure { whatever }.total
```

## Rust

```// 20210224 Rust programming solution

use rand::Rng;
use std::time::{Instant};

fn custom_function() {

let mut i = 0;
let n1: f32 = rng.gen();

while i < ( 1000000 + 1000000 * ( n1.log10() as i32 ) ) {
i = i + 1;
}
}

fn main() {

let start = Instant::now();
custom_function();
let duration = start.elapsed();

println!("Time elapsed in the custom_function() is : {:?}", duration);
}
```
Output:
```Time elapsed in the custom_function() is : 39.615455ms
```

## Scala

Define a `time` function that returns the elapsed time (in ms) to execute a block of code.

```def time(f: => Unit)={
val s = System.currentTimeMillis
f
System.currentTimeMillis - s
}
```

Can be called with a code block:

```println(time {
for(i <- 1 to 10000000) {}
})
```

Or with a function:

```def count(i:Int) = for(j <- 1 to i){}

println(time (count(10000000)))
```

## Scheme

```(time (some-function))
```

## Seed7

```\$ include "seed7_05.s7i";
include "time.s7i";
include "duration.s7i";

const func integer: identity (in integer: x) is
return x;

const func integer: sum (in integer: num) is func
result
var integer: result is 0;
local
var integer: number is 0;
begin
result := num;
for number range 1 to 1000000 do
result +:= number;
end for;
end func;

const func duration: timeIt (ref func integer: aFunction) is func
result
var duration: result is duration.value;
local
var time: before is time.value;
begin
before := time(NOW);
ignore(aFunction);
result := time(NOW) - before;
end func;

const proc: main is func
begin
writeln("Identity(4) takes " <& timeIt(identity(4)));
writeln("Sum(4)      takes " <& timeIt(sum(4)));
end func;```
Output:

of interpreted program

```Identity(4) takes 0-00-00 00:00:00.000163
Sum(4)      takes 0-00-00 00:00:00.131823
```
Output:

of compiled program (optimized with -O2)

```Identity(4) takes 0-00-00 00:00:00.000072
Sum(4)      takes 0-00-00 00:00:00.000857
```

## Sidef

```var benchmark = frequire('Benchmark')

func fac_rec(n) {
n == 0 ? 1 : (n * __FUNC__(n - 1))
}

func fac_iter(n) {
var prod = 1
n.times { |i|
prod *= i
}
prod
}

var result = benchmark.timethese(-3, Hash(
'fac_rec'  => { fac_rec(20)  },
'fac_iter' => { fac_iter(20) },
))

benchmark.cmpthese(result)
```
Output:
```Benchmark: running fac_iter, fac_rec for at least 3 CPU seconds...
fac_iter:  3 wallclock secs ( 3.23 usr +  0.00 sys =  3.23 CPU) @ 7331.89/s (n=23682)
fac_rec:  3 wallclock secs ( 3.19 usr +  0.00 sys =  3.19 CPU) @ 3551.72/s (n=11330)
Rate  fac_rec fac_iter
fac_rec  3552/s       --     -52%
fac_iter 7332/s     106%       --
```

## Slate

`[inform: 2000 factorial] timeToRun.`

## Smalltalk

(Squeak/Pharo/VisualWorks/SmalltalkX)

```Time millisecondsToRun: [
Transcript show: 2000 factorial
].
```

## SparForte

As a structured script.

```#!/usr/local/bin/spar
pragma annotate( summary, "time_function" )
@( description, "Write a program which uses a timer (with the least " )
@( description, "granularity available on your system) to time how " )
@( description, "long a function takes to execute." )
@( see_also, "http://rosettacode.org/wiki/Time_a_function" );
pragma annotate( author, "Ken O. Burtch" );

pragma restriction( no_external_commands );

procedure time_function is

procedure sample_function( num : in out integer ) is
begin
for i in 1..1000 loop
num := @+1;
end loop;
end sample_function;

start_time : calendar.time;
end_time   : calendar.time;
seconds    : duration;

procedure time_sample_function is
sample_param : integer := 4;
begin
start_time := calendar.clock;
sample_function( sample_param );
end_time := calendar.clock;
seconds := end_time - start_time;
end time_sample_function;

begin
time_sample_function;
put_line( "sum(4) takes:" & strings.image( seconds ) & " seconds." );
command_line.set_exit_status( 0 );
end time_function;
```

## Standard ML

```fun time_it (action, arg) = let
val timer = Timer.startCPUTimer ()
val _ = action arg
val times = Timer.checkCPUTimer timer
in
Time.+ (#usr times, #sys times)
end
```

### Example

```- print ("Identity(4) takes " ^ Time.toString (time_it (fn x => x, 4)) ^ " seconds.\n");
Identity(4) takes 0.000 seconds.
val it = () : unit
- fun sum (x:IntInf.int) = let
fun loop (i, sum) =
if i >= 1000000 then sum
else loop (i + 1, sum + i)
in loop (0, x)
end;
val sum = fn : IntInf.int -> IntInf.int
- print ("Sum(4) takes " ^ Time.toString (time_it (sum, 4)) ^ " seconds.\n");
Sum(4) takes 0.220 seconds.
val it = () : unit
```

## Stata

Stata can track up to 100 timers. See timer in Stata help.

```program timer_test
timer clear 1
timer on 1
sleep `0'
timer off 1
timer list 1
end

. timer_test 1000
1:      1.01 /        1 =       1.0140
```

## Swift

Using the 2-term ackermann function for demonstration.

```import Foundation

public struct TimeResult {
public var seconds: Double
public var nanoSeconds: Double

public var duration: Double { seconds + (nanoSeconds / 1e9) }

@usableFromInline
init(seconds: Double, nanoSeconds: Double) {
self.seconds = seconds
self.nanoSeconds = nanoSeconds
}
}

extension TimeResult: CustomStringConvertible {
public var description: String {
return "TimeResult(seconds: \(seconds); nanoSeconds: \(nanoSeconds); duration: \(duration)s)"
}
}

public struct ClockTimer {
@inlinable @inline(__always)
public static func time<T>(_ f: () throws -> T) rethrows -> (T, TimeResult) {
var tsi = timespec()
var tsf = timespec()

clock_gettime(CLOCK_MONOTONIC_RAW, &tsi)
let res = try f()
clock_gettime(CLOCK_MONOTONIC_RAW, &tsf)

let secondsElapsed = difftime(tsf.tv_sec, tsi.tv_sec)
let nanoSecondsElapsed = Double(tsf.tv_nsec - tsi.tv_nsec)

return (res, TimeResult(seconds: secondsElapsed, nanoSeconds: nanoSecondsElapsed))
}
}

func ackermann(m: Int, n: Int) -> Int {
switch (m, n) {
case (0, _):
return n + 1
case (_, 0):
return ackermann(m: m - 1, n: 1)
case (_, _):
return ackermann(m: m - 1, n: ackermann(m: m, n: n - 1))
}
}

let (n, t) = ClockTimer.time { ackermann(m: 3, n: 11) }

print("Took \(t.duration)s to calculate ackermann(m: 3, n: 11) = \(n)")

let (n2, t2) = ClockTimer.time { ackermann(m: 4, n: 1) }

print("Took \(t2.duration)s to calculate ackermann(m: 4, n: 1) = \(n2)")
```
Output:
```Took 0.193593682s to calculate ackermann(m: 3, n: 11) = 16381
Took 3.103710995s to calculate ackermann(m: 4, n: 1) = 65533```

## Tcl

The Tcl `time` command returns the real time elapsed averaged over a number of iterations.

```proc sum_n {n} {
for {set i 1; set sum 0.0} {\$i <= \$n} {incr i} {set sum [expr {\$sum + \$i}]}
return [expr {wide(\$sum)}]
}

puts [time {sum_n 1e6} 100]
puts [time {} 100]
```
Output:
```163551.0 microseconds per iteration
0.2 microseconds per iteration
```

## TorqueScript

Greek2me 02:16, 19 June 2012 (UTC)

Returns average time elapsed from many iterations.

```function benchmark(%times,%function,%a,%b,%c,%d,%e,%f,%g,%h,%i,%j,%k,%l,%m,%n,%o)
{
if(!isFunction(%function))
{
warn("BENCHMARKING RESULT FOR" SPC %function @ ":" NL "Function does not exist.");
return -1;
}

%start = getRealTime();

for(%i=0; %i < %times; %i++)
{
call(%function,%a,%b,%c,%d,%e,%f,%g,%h,%i,%j,%k,%l,%m,%n,%o);
}

%end = getRealTime();

%result = (%end-%start) / %times;

warn("BENCHMARKING RESULT FOR" SPC %function @ ":" NL %result);

return %result;
}```
Example:
```function exampleFunction(%var1,%var2)
{
//put stuff here
}

benchmark(500,"exampleFunction","blah","variables");

==> BENCHMARKING RESULT FOR exampleFunction:
==> 13.257```

## True BASIC

Translation of: QBasic
```SUB cont (n)
LET sum = 0
FOR i = 1 TO n
LET sum = sum+1
NEXT i
END SUB

LET timestart = TIME
CALL cont (10000000)
LET timedone = TIME

!midnight check:
IF timedone < timestart THEN LET timedone = timedone+86400
LET timeelapsed = (timedone-timestart)*1000
PRINT timeelapsed; "miliseconds."
END
```

## TUSCRIPT

```\$\$ MODE TUSCRIPT
SECTION test
LOOP n=1,999999
rest=MOD (n,1000)
IF (rest==0) Print n
ENDLOOP
ENDSECTION
time_beg=TIME ()
DO test
time_end=TIME ()
interval=TIME_INTERVAL (seconds,time_beg,time_end)
PRINT "'test' start at ",time_beg
PRINT "'test' ends  at ",time_end
PRINT "'test' takes ",interval," seconds"```
Output:
```'test' start at 2011-01-15 14:38:22
'test' ends  at 2011-01-15 14:38:31
'test' takes 9 seconds
```

## UNIX Shell

```\$ time sleep 1
```
```real    0m1.074s
user    0m0.001s
sys     0m0.006s
```

## VBA

```Public Declare Function GetTickCount Lib "kernel32.dll" () As Long
Private Function identity(x As Long) As Long
For j = 0 To 1000
identity = x
Next j
End Function
Private Function sum(ByVal num As Long) As Long
Dim t As Long
For j = 0 To 1000
t = num
For i = 0 To 10000
t = t + i
Next i
Next j
sum = t
End Function
Private Sub time_it()
Dim start_time As Long, finis_time As Long
start_time = GetTickCount
identity 1
finis_time = GetTickCount
Debug.Print "1000 times Identity(1) takes "; (finis_time - start_time); " milliseconds"
start_time = GetTickCount
sum 1
finis_time = GetTickCount
Debug.Print "1000 times Sum(1) takes "; (finis_time - start_time); " milliseconds"
End Sub
```
Output:
```1000 times Identity(1) takes  0  seconds
1000 times Sum(1) takes  296  seconds```

## Wart

```time 1+1
30000/1000000  # in microseconds
=> 2
```

## Wren

Library: Wren-check

The only way Wren currently has to time a function (encapsulated in the Benchmark.run method) is to measure the System time before and after the function is called. We therefore use that approach, averaging over say 100 runs, having first shut down as many other processes as we can.

```import "./check" for Benchmark

Benchmark.run("a function", 100, true) {
for (i in 0..1e7) {}
}
```
Output:
```Running 'a function' over 100 iteration(s):
-------------------------------------------
Best  191.172 ms
Mean  201.942 ms
Worst 208.049 ms
```

## XPL0

This works fine under pure DOS but has problems under Windows. Windows can execute other processes, although it could be argued that this should be included as part of the total time to accomplish the task at hand. DOS does go off to service a timer interrupt, but it's usually very fast, although beware of TSRs that hook this interrupt handler.

There's a more serious problem with the GetTime intrinsic under Windows XP. GetTime provides microsecond resolution by combining the BIOS timer interrupt count at location 046C with the count in the 8254 chip (or its equivalent). Unfortunately, Windows virtualizes the 8254 and thus the two values can be out of sync.

```include c:\cxpl\codes;
int T0, T1, I;
[T0:= GetTime;
for I:= 1, 1_000_000 do [];
T1:= GetTime;
IntOut(0, T1-T0); Text(0, " microseconds^M^J");
]```
Example output:

for a Duron 850 running DOS 5.0

```2354 microseconds
```

## Yabasic

```sub count(n)
local i

for i = 1 to n
next i
end sub

count(1000000)

print peek("millisrunning"), " milliseconds"

t0 = peek("millisrunning")
count(10000000)
print peek("millisrunning")-t0, " milliseconds"```

## zkl

In order to be as OS independent as possible, only system time is available.

`t:=Time.Clock.time; Atomic.sleep(3); (Time.Clock.time - t).println();`
Output:
`3`

## ZX Spectrum Basic

The ZX Spectrum has very little in the way of timing functionality; its best clock is the three-byte FRAMES variable, which starts at zero when the system is turned on and updates every time the ULA refreshes the screen, giving a granularity of one fiftieth of a second. As the system cannot multitask, a difference between the start and end time is as good as we can get; certain actions, most notably operating the system BEEPer, temporarily stop the counter.

```1 DEF FN t()=(PEEK 23672+256*PEEK 23673+65536*PEEK 23674)/50
10 LET time=FN t()
20 PRINT ASN 0.5
30 PRINT FN t()-time
```
Output:
```0.52359878
0.22

0 OK, 30:1```