I noticed that in QT Creator the default optimization level for the release version is -O2. I was wondering: why not -O3? I've read here on Stack Overflow that it can be dangerous or "bug exposing", but what are those optimizations flag which are considered to be more riskful than helpful and why?
Optimization level 3 flags (on GCC):
-fgcse-after-reload-finline-functions-fipa-cp-clone-fpredictive-commoning-ftree-vectorize-funswitch-loops