Different loops type. Speed test script

[ErosOlmi]

How fast are thinBasic loops? Here the answer.

 '-----------------------------------------------------------------------------
 'Variable declaration
 '-----------------------------------------------------------------------------
 Dim T0, T1, T2, T3, T4, T9 AS quad

 DIM MaxLoops  AS LONG VALUE 100000
 DIM Count   AS LONG
 DIM tmpNumber AS QUAD
 DIM tmpString AS STRING
 DIM Message  AS STRING
 DIM tFormat  AS STRING VALUE "#0"

 '-----------------------------------------------------------------------------
 'Confirm script execution
 '-----------------------------------------------------------------------------
 Message = "This program will perform:\n"
 Message += "" & MaxLoops & " FOR\n"
 Message += "" & MaxLoops & " WHILE/WEND\n"
 Message += "" & MaxLoops & " DO/LOOP WHILE\n"
 Message += "" & MaxLoops & " DO/LOOP UNTIL\n"
 Message += "Please press Yes to go on, NO to Stop\n"

 DIM lResult AS LONG = MSGBOX(0, Message, %MB_YESNO, "Continue?") 
 IF lResult <> %IDYES THEN
  STOP
 END IF

 T0 = GetTickCount
 
 '-----------------------------------------------------------------------------
 'Test speed: FOR loop
 '-----------------------------------------------------------------------------
 T1 = GetTickCount
 tmpNumber = 2
 FOR Count = 1 TO MaxLoops
  tmpNumber += 1
  tmpNumber = (tmpNumber * 2) ^ 2
  tmpNumber = 2
 NEXT
 
 '-----------------------------------------------------------------------------
 'Test speed: WHILE loop
 '-----------------------------------------------------------------------------
 T2 = GetTickCount
 Count = 0
 tmpString = ""
 tmpNumber = 2
 WHILE Count < MaxLoops
  Count += 1
  tmpNumber = (tmpNumber * 2) ^ 2
  tmpNumber = 2
 WEND
 
 '-----------------------------------------------------------------------------
 'Test speed: DO loop WHILE
 '-----------------------------------------------------------------------------
 T3 = GetTickCount
 Count = 0
 tmpString = ""
 tmpNumber = 2
 DO
  Count += 1
  tmpNumber = (tmpNumber * 2) ^ 2
  tmpNumber = 2
 LOOP WHILE Count < MaxLoops

 '-----------------------------------------------------------------------------
 'Test speed: DO loop UNTIL
 '-----------------------------------------------------------------------------
 T4 = GetTickCount
 Count = 0
 tmpString = ""
 tmpNumber = 2
 DO
  Count += 1
  tmpNumber = (tmpNumber * 2) ^ 2
  tmpNumber = 2
 LOOP UNTIL Count >= MaxLoops

 T9 = GetTickCount
 
 '-----------------------------------------------------------------------------
 'Show results with some internal counters
 '-----------------------------------------------------------------------------
 Message = "Test " & MaxLoops & " loops." & $CRLF
 Message += MaxLoops & " FOR"    & $tab & FORMAT$(T2 - T1, tFormat)      & " msec." & $CRLF
 Message += MaxLoops & " WHILE"   & $tab & FORMAT$(T3 - T2, tFormat)      & " msec." & $CRLF 
 Message += MaxLoops & " DO WHILE" & $tab & FORMAT$(T4 - T3, tFormat)      & " msec." & $CRLF
 Message += MaxLoops & " DO UNTIL" & $tab & FORMAT$(T9 - T4, tFormat)      & " msec." & $CRLF
 Message += "Total    "     & $tab & FORMAT$(T9 - T0, tFormat)      & " msec." & $CRLF
 Message += "Final message"     & $tab & FORMAT$(GetTickCount - T9, tFormat) & " msec." & $CRLF

 MSGBOX(0, Message)

[kryton9]

Clever test Eros. I was surprised by how much faster the do while loops were compared to the good old for loop.

[ErosOlmi]

Ken,

all those types of loop are managed internally by thinBasic core in different way.
What is best mostly depend by the processor and how thinBasic techniques best fits processor characteristics.
For example in my tests FOR/NEXT is always the best. If in your tests on AMD it is not it means the technique used is not the best on AMD processors.
Every processor manufacturer has different tips and tricks to get the max from theyr toys I suppose

In any case I think we are talking about few milliseconds difference

Ciao
Eros

[Dolphkex]

Have you observed significant variations in loop execution speed across different types, and do you think these differences are influenced by processor characteristics?