Redesign benchmarks for culture-specific string operations by adamsitnik · Pull Request #892 · dotnet/performance

adamsitnik · 2019-09-20T15:52:50Z

The culture-specific string benchmarks we had so far were using a very small and simple input and were testing very few cultures and CompareOptions. This is why we have missed issues like https://github.com/dotnet/corefx/issues/40674

This is my proposal for fixing it.

Instead of using some made-up text, we are using part of "Alice's Adventures in Wonderland" book. It contains mostly simply ASCII characters, but also some "high" chars that get special treatment and hit the slow path.

The tested matrix now is:

(new CultureInfo("en-US"), CompareOptions.Ordinal)
(new CultureInfo("en-US"), CompareOptions.OrdinalIgnoreCase)
(new CultureInfo("en-US"), CompareOptions.None)
(new CultureInfo("en-US"), CompareOptions.IgnoreCase)
(new CultureInfo("en-US"), CompareOptions.IgnoreSymbols)
(CultureInfo.InvariantCulture, CompareOptions.None)
(CultureInfo.InvariantCulture, CompareOptions.IgnoreCase)
(new CultureInfo("pl-PL"), CompareOptions.None) // as an example of complex language hitting the slow path on Unix

I've removed the old benchmarks that would now be duplicated.

Moreover I've realized that Perf_CompareInfo had a serious bug inside - the strings were always identical because source argument was never used..

performance/src/benchmarks/micro/corefx/System.Globalization/Perf.CompareInfo.cs

Lines 14 to 24 in 0c626c0

    
           private static string GenerateInputString(char source, int count, char replaceChar, int replacePos) 
        
           { 
        
               char[] str = new char[count]; 
        
               for (int i = 0; i < count; i++) 
        
               { 
        
                   str[i] = replaceChar; 
        
               } 
        
               str[replacePos] = replaceChar; 
        
               return new string(str); 
        
           }

Fixes #885

src/benchmarks/micro/corefx/System.Globalization/Perf.StringCultureSpecific.cs

tarekgh

Modulo @jkotas comments, LGTM

src/benchmarks/micro/corefx/System.Globalization/Perf.StringCultureSpecific.cs

…pendent execution paths)

…cution path, not dependent on size or high chars)

adamsitnik added 3 commits September 20, 2019 14:34

fix a bug

762f9d1

implement new benchmarks for culture-specific string operations

d8c6c02

remove benchmarks that are now duplicated with the new ones

10f9696

adamsitnik requested review from jkotas and tarekgh September 20, 2019 15:52

jkotas reviewed Sep 20, 2019

View reviewed changes