Hello
During a contest I discovered that these is a bug in the -O2 optimisation. Firstly let me state that I've actually looked at the assembly code; it's not a problem with uninitialised variables or something.
I've attached a code snippet, which is a heavy reduced version of the program that still displays the bug. Running the program w/o optimisations prints out the answer '1', as does -O1. However -O2 causes a different answer to be output. Looking at the generated assembly (from ppc386 -O2 -a -gl demo.pas) shows that the code generated for line 19 is incorrect: the first instruction is imull $24,%edx. This instruction also appears as part of the code for line 18 (to compute an offset from an array index, where $24 is related to the size of the array elements) and seems to have been mysteriously copied into line 19.
I'm using FreePascal 1.0.4 on Debian GNU/Linux from the package fp-compiler version 1.0.4-2. The kernel is 2.4.18. I've also been able to exhibit the problem with the GO32V2 version running on top of Win95 on another machine.
I'm not a member of the list, so please cc any queries to this email address.
If anyone thinks that this might be fixed in a snapshot, I'd be happy to test this. However I don't have the time for gratuitous testing.
Good luck
Bruce