[fpc-devel] Debugging Loop Unroll Optimization

Martok listbox at martoks-place.de
Wed May 16 14:57:51 CEST 2018

Hi all,

as we have discovered in 0033576 and 0033614, there is a bug somewhere in the
loop unroll optimization pass that only appears in complex enough code. The
problem is, it doesn't happen in the single testsuite test, and the observable
crashes in Lazarus are caused by memory corruption at some point unrelated to
the crash, so it's hard to debug (at least on Windows, without rr...).

I have one other project that has sporadic crashes with -OoLOOPUNROLL (I wish I
had figured that out back then), but that is about as difficult as Lazarus,
where it's at least 100% reproducible.

Does anyone have more complete test cases, or maybe smaller affected projects?


Ceterum censeo b32079 esse sanandam.

More information about the fpc-devel mailing list