AMOS:Optimizing Miscellaneous

Use extensions

speed increase: large

Get yourself a fast extension, such as AMCAF or Turbo Plus. This will only speed things up where an extension command replaces an internal command with a faster one - Easylife and AMCAF will do this for many string operations and, AMCAF, Turbo and Powerbobs do it for graphics.

Don't use:

        Plot x,y,c

Use this instead:

        Turbo Plot x,y,c (for AMCAF)
     or
        F Plot x,y,c (for Turbo Plus)

See the AMOS extensions page for a list of all known AMOS extensions and where to find them.
(or look in http://aminet.net/dev/amos Aminet's Amos directory].

Use assembler

speed increase: varies

Use assembler procedures for inner loops. Beware though, it does take a small amount of CPU time to jump to an assembler procedure, so with small routines, it's simply not worth it.

Use 'Copper Off' when doing CPU intensive work

speed increase: small

Use "Copper Off" to disable the screen while doing intense communication. The copper then stops stealing clock cycles from the processor (Unlike Multi No and such instructions, this really does work). Use "Copper On" to re-enable the normal system.

Clear an array using Fill

speed increase: large

Use Fill to clear an array to a certain value, rather than the equivilant For / Next loop.

Don't use:

        For n=0 to 1000
           A(n)=27
        Next n

Use this instead:

        Fill Varptr(A(0)) To Varptr(A(1000)),27

Use global variables

speed increase: small

Use global variables to return parameters from procedures, rather than Param.

Don't use:

        _HELLO[10,20] : pram=Param : Print pram
        Procedure _HELLO[x,y]
           temp=0
           For n=x To y
              If a(n)=0 Then temp=n : Exit
           Next n
        End Proc[temp]

Use this instead:

        Global pram
        _HELLO[10,20] : Print pram
        Procedure _HELLO[x,y]
           pram=0
           For n=x To y
              If a(n)=0 Then pram=n : Pop Proc
           Next N
        End Proc

However, don't do things like this, which are actually slower.

Don't do:

     _HELLO[10,20] : Print A
     Procedure _HELLO[X,Y]
        Shared A
        A=X*Y
     End Proc

Do this:

     _HELLO[10,20] : Print Param
     Procedure _HELLO[X,Y]
     End Proc[X*Y]

Use subroutines instead of procedures

speed increase: large

Use subroutines instead of procedures. Although they're messier, they are several times faster! Of course, with this method, you can not pass parameters, but all the variables you were using will still be accessible.

Don't use:

        _SOMETHING
        Procedure _SOMETHING
           Code
        End Proc

Use this instead:

        Gosub _SOMETHING
        _SOMETHING:
           Code
        Return