[GitHub] [lucenenet] jeme commented on pull request #347: Move call to debugging flag out of loops calling FixedBitSet.Get/Set

[GitBox <gi...@apache.org>]

jeme commented on pull request #347:
URL: https://github.com/apache/lucenenet/pull/347#issuecomment-698815793


   Maybe a bit discouraging but in a simple benchmark, this doesn't seem to have any positive impact.
   
   ``` ini
   
   BenchmarkDotNet=v0.12.1, OS=Windows 10.0.18363.1016 (1909/November2018Update/19H2)
   Intel Core i7-6700 CPU 3.40GHz (Skylake), 1 CPU, 8 logical and 4 physical cores
     [Host]     : .NET Framework 4.8 (4.8.4200.0), X86 LegacyJIT
     DefaultJob : .NET Framework 4.8 (4.8.4200.0), X86 LegacyJIT
   
   
   ```
   |                     Method |       Mean |    Error |   StdDev |
   |--------------------------- |-----------:|---------:|---------:|
   |                 CacheValue |   320.7 ns |  6.34 ns |  7.30 ns |
   |              NonCacheValue |   318.5 ns |  4.74 ns |  4.20 ns |
   |    CacheValue_PassToMethod | 6,687.3 ns | 47.91 ns | 40.01 ns |
   | NonCacheValue_PassToMethod | 6,640.5 ns | 32.99 ns | 30.86 ns |
   
   ----
   
   ```csharp
      public class Benchmark
       {
   
   
           [Benchmark]
           public void CacheValue()
           {
               int counter = 0;
               bool cached = ValueSource.Value;
               for (int i = 0; i < 1000; i++)
                   if (cached)
                       counter++;
           }
   
           [Benchmark]
           public void NonCacheValue()
           {
               int counter = 0;
               for (int i = 0; i < 1000; i++)
                   if (ValueSource.Value)
                       counter++;
           }
   
           [Benchmark]
           public void CacheValue_PassToMethod()
           {
               bool cached = ValueSource.Value;
               for (int i = 0; i < 100; i++)
                   DooWork(cached);
           }
   
           [Benchmark]
           public void NonCacheValue_PassToMethod()
           {
               for (int i = 0; i < 100; i++)
                   DooWork();
           }
   
           public void DooWork(bool workMore)
           {
               int counter = 0;
               for (int i = 0; i < 100; i++)
                   if (workMore)
                       counter++;
           } 
           
           public void DooWork()
           {
               int counter = 0;
               for (int i = 0; i < 100; i++)
                   if (ValueSource.Value)
                       counter++;
           }
       }
   ```
   
   Obviously benchmarks of the actual code could prove to have different results.
   
   Caching the boolean flag using a Lazy seems very reasonable.
    


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