[fpc-devel] Finally fixed that MOVZX/SX optimisation!

Joost van der Sluis joost at cnoc.nl
Wed Feb 19 00:12:21 CET 2020

Op 18-02-2020 om 23:04 schreef J. Gareth Moreton:
> It seems that not all regressions are caught when you run the test suite 
> conventionally, and you have to specify additional options like "-O4", 
> which may cause other failures to occur if a test is not expecting any 
> kind of intense optimisation, for example.  In response, over here at 
> https://bugs.freepascal.org/view.php?id=36687, I've introduced two new 
> tests that are copies of the ones that failed, but which explicitly add 
> -O4 to the default compiler options.

In fact, *all* test should succeed with an option like -O4. So, 
following your approach we have to add copies for all tests, with all 
possible combination of compiler-options. That's undo-able and that is 
why this isn't done.

So when you are working on optimizations, it might be a good idea to run 
the complete test-suite with optimizations enabled (-O4) on your local 

We also realize that it is undo-able to test with all 
optimization-settings, but to make our live easier, there are nightly 
(daily) tests with all sort of options. You can find the results here:


For example, the latest x86_64-linux run with -O4:



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