4 ms·
-O3 also makes build times longer (sometimes significantly), and occasionally the resulting program is actually slightly slower than -O2. IME -O3 should only b
by hmry 6mo ago
-O3 also makes build times longer (sometimes significantly), and occasionally the resulting program is actually slightly slower than -O2.
IME -O3 should only be used if you have benchmarks that show -O3 actually produces a speedup for your specific codebase.
- fyrn_ 6mo agoThis various a lot between compilers. Clang for example treats O3 perf regressions a bugs In many cases at least) and is a bit more reasonable with O3 on. GCC goes full mad max and you don't know what it's going to do.