From: Markus L?ll

So out of curiosity i took the definitions given in this thread, and tried to run timing-tests. Here's what I ran:

...

ghc -prof -auto-all -o Test Test.h Test +RTS -p and then looked in the Test.prof file.

I think this is a poor approach for timing tests, for two reasons: 1) -O or -O2. Reporting performance results from non-optimized builds is often highly misleading. 2) -auto-all inhibits performance of code, sometimes significantly. You'd be better off using a non-profiling build and criterion. Plus criterion does the statistics for you and warns about possibly invalid samples. John