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

[Tech Benner]

HI Rohit,

My concern about optimisation was to do with the test example only, 
using the same parameters many times to show up a measurable time 
difference.

Cheers

Gary


On 16/08/2022 9:54 am, Rohit Gupta wrote:
>
> 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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