[Performance] std.conv.toInt is damn fast!

[Bill Baxter]

Andrey Khropov wrote:
> Burton Radons wrote:
> 
> 
>>Use std.conv.toInt instead, although from the looks of the implementation,
>>that will be slightly slower as well.
> 
> 
> Thanks for the advice. As a matter of fact it is faster than C's atoi!
> And better handles errors (through exceptions)
> 
> D-std.conv.toInt: 277 ms elapsed (mean).
> vs
> D-std.c.stdlib.atoi: 348 ms elapsed (mean).
> 
> And it's really the fastest implementation among the different languages std
> libraries:
> 
> Here is the list of results for different languages and implementations
> (all optimization options were turned to the maximum):
> 
> 1) DMD 0.173 (toInt)	      				- 0.277 sec
> 2) MinGW GCC 3.4.2 (atoi)  	 			- 0.345 sec
> 3) MS VC++ 8.0 (atoi)       				- 0.645 sec
> 4) C# on Mono 1.1.18 (int.Parse)    			- 1.023 sec
> 5) Java on HotSpot 1.5.0_08 (Integer.decode)	- 1.796 sec (-server)
> 6) Java on JRockit 26.4.0 (Integer.decode)		- 1.969 sec (-server, that's the
> mean for 5 runs, first run (when Jitting is performed) is 2.905 sec)
> 7) C# on .NET 2.0 (int.Parse)				- 2.899 sec (haven't yet downloaded .NET 3.0)
> 8) CPython 2.4.2 + Psyco 1.5 (int())			- 5.406 sec
> 9) IronPython 1.0 on Mono 1.1.18 (int())		- 10.625 sec 
> 10) IronPython 1.0 on .NET 2.0 (int())		- 10.685 sec 
> 11) CPython 2.4.2 (int())					- 11.218 sec
> 12) MinGW GCC 3.4.2 
>    (boost 1.33.1::lexical_cast<int>)  		- 21.305 sec
> 13) MS VC++ 8.0 
>    (boost 1.33.1::lexical_cast<int>)			- 51.700 sec (Yes, it's hard to believe
> but check yourself!)
> 
> I actually cannot believe it, but D's std.conv.toInt is almost 100x faster than
> boost version!
> 


Holy moly!  Now that's dedication!  You must really have a lot of 
strings you need to convert to integers!

--bb