[swift-users] Performance critical code in Swift

[Игорь Никитин]

I got it. Thanks for your tips!

> 2 окт. 2016 г., в 0:13, Jens Persson <jens at bitcycle.com> написал(а):
> 
> You could write some examples in both C and Swift in order to gain experience in how to write your Swift code so that it will (probably) run as fast as (or faster than) your corresponding C code.
> 
> I've done this for a number of different performance critical things and it is often possible to get the Swift version as fast as the C version.
> 
> (If you find something that is not possible (or unnecessarily cumbersome) to write as fast in Swift as in C, you could probably file a bug/improvement on bugs.swift.org. I did this some time ago when I noticed that Swift's optimizer missed an opportunity to unroll loops in a certain situation and it turned out that a fix/optimizer-improvement was already on its way.)
> 
> You must of course profile/microbenchmark your code in some meaningful way, setting all relevant compiler flags for both C and Swift, preventing dead code elimination, measuring average or perhaps median times of lots of tests, making sure what should and shouldn't be statically knowable, etc.
> 
> In Swift you probably want -O -whole-module-optimization, and (rarely) you might want/need to disable safety checks.
> 
> /Jens
> 
> 
> 
>> On Sat, Oct 1, 2016 at 10:33 PM, Daniel Dunbar via swift-users <swift-users at swift.org> wrote:
>> Yes, it is possible. Exactly how much use of Unsafe style idioms and other performance-focused "workarounds" it requires depends a lot on the code in question. Can you say more about your problem area?
>> 
>>  - Daniel
>> 
>> > On Oct 1, 2016, at 1:30 PM, Игорь Никитин via swift-users <swift-users at swift.org> wrote:
>> >
>> > Hello!
>> > Is it possible for Swift to be as fast as C when writing performance critical code? Of course if using C Standard Library for instead of Foundation (and so on) and getting rid of dynamic dispatch and reference types.
>> > Or I need just to use C?
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