[DUG] Int64 or floating point faster?

[Jolyon Smith]

That's curious.  Who are "they" ?  It doesn't sound like any floating point
implementation I ever came across in Delphi (or anywhere else, for that
matter).  O.o


On 17 August 2014 12:28, Pieter De Wit <pieter at insync.za.net> wrote:

>  Hi Jolyon,
>
> From memory, they used 2 int32's to make a float - this could have been
> int16's - memory is very vague on this :) The one was used to represent the
> whole numbers and the other was to show the decimal numbers
>
> Cheers,
>
> Pieter
>
>
> On 17/08/2014 12:05, Jolyon Smith wrote:
>
> @Pieter - I don't understand what you mean when you say that "float was
> int32.int32".  For starters, "float" is an imprecise term.  If you mean
> "single" then the entire value was always 32 bit in it's entirety.  If you
> mean double then it was always 64 bit.  What is this "in32.int32" type of
> which you speak ?  O.o
>
>
> On 17 August 2014 11:52, Jolyon Smith <jsmith at deltics.co.nz> wrote:
>
>> I think there are too many variables involved to give an answer to this
>> question without some of those variables being reduced to known values.
>>
>> e.g.  what hardware ?  what version of Delphi ?  x64 target or x86 ?
>>  what precision of floating point ?
>>
>> Having said that, in a quick test knocked up in my Smoketest framework I
>> found that Double comfortably outperforms Int64 when compiling for Win32
>> but that both Double and Int64 demonstrated improved performance when
>> compiling for Win64 and that whilst Double still showed some advantage it
>> was not as significant (and in some test runs the difference was
>> negligible).
>>
>> If you are targeting FireMonkey you will have to bear in mind that the
>> back-end compiler is different to the x86/x64 backend, so results obtained
>> using the WinXX compilers will not necessarily be indicative of performance
>> on the ARM or LLVM platforms.
>>
>>
>> Conditions:
>>
>>  - Delphi XE4
>>  - Running in a 64-bit Win 7 VM
>>   - No testing was done for correctness of the results.
>>
>>
>>
>>
>>
>>  On 16 August 2014 15:30, Ross Levis <ross at stationplaylist.com> wrote:
>>
>>>   Would I be correct that int64 multiplications would be faster than
>>> floating point in Delphi?  My app needs to do several million.
>>>
>>>
>>>
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>>
>
>
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