4 ms·In practice, gcc and clang implement it so it's portable /sby Matheus28 6y agoIn practice, gcc and clang implement it so it's portable /sstrictfp 6y agoBut technically it's UB, so you shouldn't use it.nickelpro 6y agoFor the curious, this exact series of comments _is_ mandated by the standard and therefore be reliably located in every thread that involves C/C++.