[DUG] Curious re efficiency of using in [set of integer]

[Rohit Gupta]

Ross, that was my expectation, that the SET would be slightly faster.

The *set *should *fetch *the data, *shift *it and *and *it.

Where as the *or *should *fetch *the data and execute two *compare *and 
*jump *type instructions.

In this case, I doubt if the optimisation would make much difference.  
Optimisation make a significant difference to loops and where a 
variable/constant is used again and again.

Regards

*Rohit Gupta*
B.E. Elec., M.E., Mem IEEE, Member IET

On 15/08/2022 22:51, Ross Levis wrote:
>
> I did the test but had to use a loop 40000000 times to get some 
> separation.  The in set statement was actually faster than doing 2 
> “or” statements.  Around 76 to 65 ticks. Basically identical and both 
> too fast to be concerned with.
>
> *From:*delphi-bounces at listserver.123.net.nz 
> [mailto:delphi-bounces at listserver.123.net.nz] *On Behalf Of *Ross Levis
> *Sent:* Monday, 15 August 2022 6:11 pm
> *To:* 'NZ Borland Developers Group - Delphi List'
> *Cc:* delphi at delphi.org.nz
> *Subject:* Re: [DUG] Curious re efficiency of using in [set of integer]
>
> I should do that.
>
> It may matter if it’s converting to something expensive code in ASM, 
> and this code is being executed a few thousand times.
>
> *From:*delphi-bounces at listserver.123.net.nz 
> [mailto:delphi-bounces at listserver.123.net.nz] *On Behalf Of *Rohit Gupta
> *Sent:* Monday, 15 August 2022 6:01 pm
> *To:* NZ Borland Developers Group - Delphi List
> *Cc:* delphi at delphi.org.nz
> *Subject:* Re: [DUG] Curious re efficiency of using in [set of integer]
>
> Just put it in a loop of 10k and time it.
>
> But honestly, does it really matter?
>
> Regards
> Rohit
>
> 15/08/2022 17:34:14 Ross Levis <ross at stationplaylist.com>:
>
>     Var Total: Integer;
>
>     If I want to test 2 or 3 values of an integer, I often use
>
>     *if Total in [4,6] then ...*
>
>     But is that more or less efficient for the CPU/ASM coding than
>
>     *if (Total = 4) or (Total = 6) then ...*
>
>     I’m not sure how to find out myself.
>
>
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