Shouldn't suggest using -O3 about tinyrenderer HOT 2 CLOSED

I'm very late, but you appear to confuse -O3 (standards compliant) with -Ofast (explicitly non-standards compliant). -O3 is entirely safe providing your code is correct. Packages sometimes break with -O3 because they are not correct, and the analysis at -O3 can prove as such.

For modern, new programs there is very little reason to prefer -O2 over -O3 unless you're doing very hairy things with templates, especially because the more detailed flow analysis of -O3 can produce warnings (find bugs) that -O2 does not.

from tinyrenderer.

...very late also, but I believe you are correct. I was remembering warnings not to use -O3 because a lot of code is not correct, and hasn't been fixed.

from tinyrenderer.