Avoiding Compiler Screwups?

[Baker]

Are there any special tricks to avoiding compiler screwups?

Here is one that is bothering me right now .... Using maximum optimization, ambient sounds aren't playing until pressing ALT-TAB and switching away or back. Both using GCC and using Visual Studio. Maybe even more than that. Of course the debug build works fine.

The most aggressive optimizations don't seem to add any fps or performance, but they sure do screw up small things in subtle ways.

I've had the compiler poorly round floats so that multiplying by 100 ends up being slightly short of x 100 in multiplication against an integer before. There is a block of original Quake source code in software I have wrapped with #pragma optimize ("off") / #pragma optimize ("on") to keep the compiler from foobaring it.

Sometimes I kind of wonder whether just to use slightly less than the best optimization to prevent this kind of subtle chaos.

[Spike]

bugs like that suggest that you're not initialising something properly.
try valgrind.

[qbism]

Pentium optimizations can have errors related to FP precision. Anything below P4/ss3 or thereabouts

[Baker]

I've used a few different tools like Very Sleep and Microsoft Application Verifier, nothing.

After further examination, the sound issue might not have been code related at all. I think one of the tabs in my web browser was responsible or something running in the background.

[Baker]

[qbism]

Separate packet update rate from refresh rate?

[Spike]

fte just uses a float internally and just copies that over to the master_vol field, apparently.
well done finding it though, such things can be annoying (especially that ambient noise stuff anyway).

[Baker]

[revelator]

One thing to also look out for are floating point precision when it comes to msvc.
Msvc from version 2012 and up have replaced floating point precision with SSE math so if you get weird behaviour ill look at that.
This was discovered because vanilla doom3's stencil shadows fucked up totally when compiled with msvc 2012, so stick to 2010 if you cannot fix the code.