[fpc-devel] Detecting SSE and AVX compiler options

Florian Klämpfl florian at freepascal.org
Sun Feb 3 23:05:58 CET 2019

Am 03.02.19 um 21:52 schrieb J. Gareth Moreton:
> It just seems highly dependent on the source code and can easily break 
> if it's changed... and not just the Floor function, but also possibly if 
> Trunc and Frac are modified in some way.  The code does boil down to two 
> instructions in SSE 4.1 and AVX, but it depends on many different nodes 
> with an exact arrangement, and if something is changed (but still 
> functionally equivalent), the optimisation will break.

Well, yes. But maybe its possible to create a reasonable test and take 
care of most imaginable situations.

More information about the fpc-devel mailing list